Meridian — Product Design System

The user wants a design system for their product. They haven't specified what the product is, so I need to make reasonable assumptions. The request is: 1. Design tokens (color, typography, spacing) 2. Standardized components (buttons, forms, cards) as high-fidelity mockups Since no product context is given, I should build a comprehensive, professional design system that could serve as a starting point for a SaaS/product application. I'll make it generic enough to be adaptable but specific enough to be useful — a complete single-file HTML page that presents the design system as a living documentation site. Let me think about what makes a design system page exceptional rather than generic: **Concept**: I'll design the design system itself as a beautifully crafted "brand book" / documentation site. The design system needs a name and identity — let me call it something distinctive. Maybe "Meridian" or "Cadence" or "Baseline" — "Baseline" is fitting for a design system (typography baselines, grid baselines). Or "Northlight". Let me go with "Cadence" — it evokes rhythm, consistency, systematic design. Actually "Meridian" sounds more premium. Let me think... "Halcyon"? "Foundry"? "Foundry" is nice — a foundry is where type is made, and it suggests a system for forging components. Let me go with "Foundry" — a design system. Actually, let me pick "Meridian Design System" — meridian lines are reference lines, which is exactly what a design system is. Good metaphor. Or "Vantage". Hmm. "Meridian" it is... actually let me reconsider — "Baseline" is very literal and good. But maybe something more evocative. Let me go with **"Lumen"** — no, too common. **"Kelp"**? No. **"Ridgeline"**? **"Meridian"** works well. Final: Meridian. **Visual direction**: I need to avoid generic blue/purple, gradients, emoji, Inter/Roboto. Let me pick a distinctive palette: - Primary: A deep warm ink/near-black with a vivid accent. Options: burnt orange/terracotta, forest green, oxblood red, mustard/amber. - A sophisticated choice: warm off-white paper background (#FAF8F5 type), deep ink text (#1A1815), and a rich accent like a deep terracotta/rust (#C2492D or similar) plus a supporting teal/forest. - Or: dark editorial style with cream and a vivid signal color like electric moss green or international orange. Let me design a dual-theme system actually — the design system should demonstrate light theme primarily, maybe with a dark mode toggle. A theme toggle would be a great interactive element showing tokens in action! That's a signature moment: flip the theme and watch every token, swatch, and component re-render live. Yes — that demonstrates the whole point of tokens (semantic tokens remapping). **Typography**: Avoid Inter/Roboto/Arial/system-ui as primary. Good options from Google Fonts: - Display/headings: "Fraunces" (variable serif, characterful), "Space Grotesk", "Sora", "Newsreader", "Instrument Serif", "Gambetta" (not on Google), "Bricolage Grotesque" (distinctive!), "Clash Display" (Fontshare). - Body: "Instrument Sans", "Public Sans", "Söhne" (not free), "General Sans" (Fontshare), "Archivo". - Mono: "JetBrains Mono", "IBM Plex Mono", "Fragment Mono", "Spline Sans Mono". Let me use: **Bricolage Grotesque** for display (very characterful, variable, distinctive) + **Instrument Sans** for body/UI + **JetBrains Mono** or **Spline Sans Mono** for code/tokens. Actually pairing Bricolage with Instrument Sans is nice. Fontshare's "Clash Display" + "General Sans" is also great but Fontshare CDN can be less reliable. I'll stick with Google Fonts: Bricolage Grotesque + Instrument Sans + JetBrains Mono. **Layout**: Avoid dashboard feel and equal 3-column card rows. The documentation should feel like an editorial spec sheet: - Left sidebar navigation (fixed) with section index — that's conventional for design systems but functional. I could make it more interesting: a slim fixed rail with numbered sections. - Main content: sections with big editorial headers, asymmetric layouts. - Sticky top bar with theme toggle and system name. Sections: 1. **Foundations / Principles** — brief intro, design principles (3-4 short statements, not cards... maybe a numbered list with big numerals) 2. **Color tokens** — semantic swatches with hex/rgb values, copy-on-click (toast feedback), primitive scales (e.g., accent scale from 50–900), contrast ratios shown (I can actually compute WCAG contrast ratio live — that's a nice craft detail!) 3. **Typography** — type scale specimens with sizes, weights, line-heights, live font-feature demo 4. **Spacing & grid** — spacing scale visualized (bars), radius scale, elevation/shadows 5. **Buttons** — all variants (primary, secondary, ghost, danger), sizes, states (hover/active/disabled/loading), interactive demos 6. **Forms** — text input, textarea, select, checkbox, radio, toggle/switch, validation states, an actual working demo form with real validation 7. **Cards** — a few card compositions (content card, stat/metric card, profile card, media card) but arranged asymmetrically, not a uniform 3-col row 8. Maybe: **Badges/tags, alerts/toasts** — could add small extras but keep scope focused. The user asked for buttons, forms, cards specifically. I could add a small "more components" section with badges, alerts to show extensibility. Keep it tasteful. 9. **Tokens as code** — a section showing the JSON/CSS variables export? Could be a nice touch: a tabbed code block showing tokens.json / tokens.css, with copy button. That makes it feel like a real deliverable. **Interactivity** (must be real, wired): - Theme toggle (light/dark) — remaps semantic tokens - Click-to-copy on every token swatch and code value → custom toast notification - Live contrast ratio computation for color pairs - Button demos actually clickable with press states, loading spinner state demo - Form demo with real validation (email, required, char count on textarea) - Toggle switches functional - Tabs in code section - Sidebar scrollspy highlighting active section - Maybe a density toggle (comfortable/compact)? That's another great token demo — spacing tokens remap. Could be nice but might complicate. Theme toggle is enough; maybe add density as second toggle in topbar. Let's do it — it powerfully demonstrates tokens. Actually, density toggle affects component padding via a `data-density` attribute on root. Manageable. **Signature moment**: The hero. A big typographic hero with the system name, maybe a live "token playground" — hmm. Or the hero could feature an animated specimen: giant "Aa" in Bricolage with weight/width axes controlled by sliders — a live variable font playground! That's memorable and demonstrates typography tokens. Bricolage Grotesque has variable axes: weight (200–800), width (75–100), optical size (12–96). Sliders controlling a giant specimen = great signature interaction. I'll put a variable font playground in the typography section, or in the hero. Hero: giant wordmark "Meridian" with maybe the specimen sliders right there. Let me put the playground in the Typography section to keep the hero clean but striking. Hero idea: Large serif/grotesque headline, an ink-on-paper feel, with a right-aligned column of meta info (version, tokens count, etc.), plus maybe an interactive swatch strip that cycles. Keep it editorial. Another signature idea: the color section where clicking a swatch copies and a small toast appears; also hovering a semantic token row shows its resolved primitive. Let me now define the actual token values. **Color system** — warm paper + ink + terracotta accent + deep green support: Light theme: - `--paper` / bg-canvas: #F7F4EE (warm paper) - `--bg-surface`: #FFFFFF (cards) - `--bg-subtle`: #EFEAE2 (wells, code blocks maybe darker) - `--ink` / text-primary: #1C1917 or warmer #201D1A - `--text-secondary`: #57534E-ish warm gray → #5C564D - `--text-muted`: #8A8378 - `--border`: #E2DCD1 / #DDD5C7 - `--border-strong`: #B9B0A0 Accent (primary): terracotta/rust — scale: - 50 #FBF3EF? Let me craft a scale around hue ~18–20°: - 100 #F9E8E0 - 200 #F2CDBD - 300 #E7AA8F - 400 #DB855F - 500 #C9632F? Hmm. Let me pick a strong 500: #C14E24 or #C2492D. I'll craft: - 300 #E8A87C - 400 #D97B47 - 500 #C25A2B (primary) — check contrast with white: #C25A2B luminance… roughly (194,90,43). Relative luminance: R=194/255=0.7608→linear 0.5394? Let me compute: c=0.7608, ((c+0.055)/1.055)^2.4 = (0.8158/1.055)=0.7733^2.4. ln0.7733≈-0.2571, ×2.4≈-0.6170, e^-0.617≈0.5395. G=90/255=0.3529→(0.4079/1.055)=0.3866^2.4: ln≈-0.9503×2.4=-2.2807→0.1022. B=43/255=0.1686→(0.2236/1.055)=0.2119^2.4: ln≈-1.5517×2.4=-3.724→0.0241. L=0.2126×0.5395+0.7152×0.1022+0.0722×0.0241=0.1147+0.0731+0.0017=0.1895. Contrast with white: (1.05)/(0.2395)=4.38. Slightly below 4.5 for normal text but fine for large/bold button text… For AA normal text I'd want ≥4.5. Darken 500 to #B04A1E? Or use white text on 600. Better: make primary button use `--accent-600` #A8431F as bg with white text, hover 700. Let me compute #A8431F: (168,67,31). R:0.6588→((0.7138)/1.055)? Wait formula: if c>0.03928, ((c+0.055)/1.055)^2.4. c=0.6588→(0.7138/1.055)=0.6766^2.4: ln≈-0.3907×2.4=-0.9377→0.3915. G=67/255=0.2627→(0.3177/1.055)=0.3012^2.4: ln≈-1.2000×2.4=-2.880→0.0561. B=31/255=0.1216→(0.1766/1.055)=0.1674^2.4: ln≈-1.7876×2.4=-4.290→0.0137. L=0.2126×0.3915+0.7152×0.0561+0.0722×0.0137=0.0832+0.0401+0.0010=0.1243. Contrast w/ white=1.05/0.1743=6.02. So define accent scale: - 50: #FCF4EE - 100: #F7E3D5 - 200: #EEC6AB - 300: #E2A277 - 400: #D57F4A - 500: #C25E2B - 600: #A8431F ← primary action - 700: #86351A - 800: #5F2512 - 900: #3D170B Secondary/success/warning/danger: - Success: deep green — 600 #2E6B45? contrast w/white: (46,107,69): R 0.1804→(0.2354/1.055)=0.2231^2.4: ln≈-1.4999×2.4=-3.5998→0.0273. G 0.4196→(0.4746/1.055)=0.4499^2.4: ln≈-0.7987×2.4=-1.9169→0.1471. B 0.2706→(0.3256/1.055)=0.3086^2.4: ln≈-1.1757×2.4=-2.8217→0.0594. L=0.2126×0.0273+0.7152×0.1471+0.0722×0.0594=0.0058+0.1052+0.0043=0.1153. Contrast=1.05/0.1653=6.35. Good. Scale around green hue 150ish. - Warning: amber/ochre — 600 #9A6A00-ish, dark text on it. #B47A0A? Warning usually pairs with dark ink text. Use #8F5F00 for text-on-light? I'll define warning 500 #D9930D (icon/bg-tint) and text-warning as #7A5200. - Danger: oxblood red — 600 #B3321F? contrast: (179,50,31): R 0.7020→(0.7570/1.055)=0.7175^2.4: ln≈-0.3319×2.4=-0.7966→0.4509. G 0.1961→(0.2511/1.055)=0.2380^2.4: ln≈-1.4355×2.4=-3.4452→0.0319. B 0.1216→0.0137 (from before). L=0.2126×0.4509+0.7152×0.0319+0.0722×0.0137=0.0959+0.0228+0.0010=0.1197. Contrast=1.05/0.1697=6.19. Good. Danger scale hue ~8°. - Info: could use a slate blue — but I want to avoid default blue vibes; a desaturated steel blue is fine as semantic (it's functional, not brand). #33628C-ish? Or teal #1F6E6B. Teal fits the palette better. Info = teal #176B63? Let me use a proper blue-leaning teal: 600 #0F6A5E? Hmm, info as teal conflicts slightly with success green. Use a desaturated indigo/steel: #4C5F9E? Meh. I'll just include success/warning/danger and treat accent as the action color; add "info" as teal #14655F. Actually to keep semantic completeness (success, warning, danger, info) I'll include info as a muted steel blue #3E5F8A — it's a functional token, acceptable. Or skip info. I'll include it as "info" with a slate-teal #2A6072. Fine. Dark theme remapping: - bg-canvas: #16130F (warm near-black) - bg-surface: #1F1B16 - bg-subtle: #26211A - text-primary: #F1EDE4 - text-secondary: #B5AC9E - text-muted: #857C6E - border: #35302687? just #353027, border-strong #4A443A - accent shifts lighter: primary action bg accent-400 #D57F4A with dark ink text? On dark theme, primary button: bg #D57F4A text #1C1917 — contrast: L(#D57F4A): (213,127,74): R 0.8353→(0.8903/1.055)=0.8439^2.4: ln≈-0.1697×2.4=-0.4073→0.6654. G 0.4980→(0.5530/1.055)=0.5242^2.4: ln≈-0.6459×2.4=-1.5502→0.2122. B 0.2902→(0.3452/1.055)=0.3272^2.4: ln≈-1.1172×2.4=-2.6813→0.0685. L=0.2126×0.6654+0.7152×0.2122+0.0722×0.0685=0.1415+0.1518+0.0049=0.2982. Contrast with #16130F: L of #16130F ≈ (22,19,15): R 0.0863→(0.1413/1.055)=0.1339^2.4: ln≈-2.0107×2.4=-4.8257→0.0080. G 0.0745→(0.1295/1.055)=0.1228^2.4: ln≈-2.0971×2.4=-5.033→0.0065. B 0.0588→(0.1138/1.055)=0.1079^2.4: ln≈-2.2268×2.4=-5.344→0.0048. L=0.2126×0.0080+0.7152×0.0065+0.0722×0.0048=0.0017+0.0047+0.0003=0.0067. Contrast=(0.2982+0.05)/(0.0067+0.05)=0.3482/0.0567=6.14. Good — dark text on accent-400 works in dark mode. I'll implement semantic tokens as CSS custom properties that flip under `[data-theme="dark"]`. Primitive scales stay constant (displayed as swatch rows). **Typography scale** (base 16px, ratio ~1.25 with adjustments): - display-xl: clamp(3rem, 6vw, 4.5rem) / 1.05, weight 700, Bricolage, letter-spacing -0.03em - display: 3rem/1.1 (48) - h1: 2.25rem (36) - h2: 1.75rem (28) - h3: 1.375rem (22) - h4 / title: 1.125rem (18) - body-lg: 1.125rem/1.6 - body: 1rem/1.6 - body-sm: 0.875rem/1.5 - caption/label: 0.8125rem (13), uppercase label variant with tracking - mono-sm: 0.8125rem Display specimen section: each row shows sample text at that size with meta (name, px/rem, weight, line-height). Maybe show "Aa" + sentence. **Spacing scale**: 4px base: 4, 8, 12, 16, 24, 32, 48, 64, 96 → tokens space-1..space-9. Visualize as bars with labels. Radius: 0(sm?) actually: radius-xs 4, sm 6? Let me define: sm 6, md 10, lg 16, xl 24, full 999. Or simpler: 4/8/12/16/999. I'll do: xs 4, sm 8, md 12, lg 20, full. Shadows: elevation-0..3 warm-tinted shadows (shadow color from ink with low alpha). Also border widths. **Components**: Buttons: variants primary (solid accent), secondary (outline/ink border), tertiary/ghost (text only), danger, plus sizes sm/md/lg, states: hover, active, focus-visible ring, disabled, loading (spinner). Show a live row + a "state matrix" showing hover/pressed/disabled rendered as static states (with .is-hover classes) so users can see all states at once. Clicking live buttons triggers a toast ("Primary button clicked") to prove wiring. Forms: - Text field (label, hint, required marker) - Field with error state (message with icon) - Field with success - Textarea with character counter (live) - Select (custom styled native select) - Checkbox (custom, with indeterminate example) - Radio group - Switch/toggle (functional, updates a status line) - A working demo form at the end: "Create project" form with validation — on submit, validates, shows inline errors or success toast + confetti? No confetti, keep restrained. Success → toast + form resets. Custom checkboxes/radios/switch need careful CSS with accent color, focus rings, disabled states. Cards: compositions — - Article/content card (image placeholder via picsum, tag, title, meta, action) - Metric card (number with delta, sparkline? A tiny inline SVG sparkline — hand-drawn, fine; or bar micro-chart) - Team/member card with avatar (initials-based avatar, no image needed) - Maybe a horizontal "list-item card" / notification card Arrange asymmetrically: e.g., a 12-col grid where article card spans 7, metric column spans 5 with two stacked metric cards, etc. Not uniform 3-col. Icons: use an icon library — Lucide via CDN? Lucide has a script that replaces ``. Or use inline SVGs hand-authored. Lucide CDN (unpkg lucide@latest) with `lucide.createIcons()` is reliable. I'll use Lucide. Toast system: custom, bottom-right or bottom-center, with icon, message, auto-dismiss, stacking. Contrast checker: for each semantic color pair (text on bg etc.), compute WCAG ratio and show badge (AAA/AA/AA18/Large). I'll write a JS function to compute luminance from hex. Scrollspy: IntersectionObserver on sections updating sidebar nav. Density toggle: `data-density="compact"` reduces paddings/font-size of components slightly — implement via CSS vars `--ctrl-pad-y` etc. Copy-to-clipboard: navigator.clipboard with fallback (execCommand) → toast. Code export section: tabs [tokens.css | tokens.json] showing a condensed sample; copy button. Content in `
` — must escape braces fine in HTML; just write text. Structure plan (single HTML file): ``` fonts: Bricolage Grotesque (wght 200..800, width?), Instrument Sans, JetBrains Mono lucide script logo mark, nav sections (numbered), theme toggle? theme toggle in topbar. Sidebar has scrollspy nav + version footer. breadcrumb-ish "Meridian / Foundations", right: density toggle, theme toggle big title, meta grid, principles list primitives scales + semantic tokens table w/ contrast scale specimens + variable playground (sliders) spacing bars, radius, elevation variants, sizes, states matrix, interactive field anatomy + all controls + demo form asymmetric compositions code tabs ``` Mobile: sidebar collapses to top or hidden; I'll make sidebar hidden below 1024px with a simple top nav or just hide it (doc page). I'll hide sidebar on small screens and show a compact horizontal nav maybe. Keep simple: hide sidebar, sections stack. Let me carefully design the aesthetics: - Paper background #F7F4EE; sidebar slightly different (#F2EEE6) with right border. - Headings in Bricolage Grotesque, weight 600–700, tight tracking. - Section headers: small mono index number ("01") + rule line + big heading + description. Editorial. - Use hairline borders generously (1px #E4DDD0) to create that spec-sheet feel. - Accent used sparingly: interactive states, primary buttons, active nav marker, small accents. - Dark theme flips all. Avoid uniform card grids. For color primitives, a row of swatches per hue is fine (it's a scale, that's genuine structure, not filler). Semantic tokens: table-like rows. Now the variable font playground: Bricolage Grotesque variable axes on Google Fonts: opsz 12–96, wdth 75–100, wght 200–800. I need to load it as variable font: `family=Bricolage+Grotesque:opsz,wdth,wght@12..96,75..100,200..800`. Then sliders for wght/wdth/opsz adjusting font-variation-settings on a big specimen "Aa Rg". Show live CSS output `font-variation-settings: "opsz" 96, "wdth" 100, "wght" 700;` with copy button. Google fonts URL: https://fonts.googleapis.com/css2?family=Bricolage+Grotesque:opsz,wdth,wght@12..96,75..100,200..800&family=Instrument+Sans:ital,wght@0,400..700;1,400..700&family=JetBrains+Mono:wght@400;500;600&display=swap Instrument Sans is variable 400..700. Good. Lucide: `` then `lucide.createIcons()`. Icons needed: sun/moon, check, copy, x, alert-circle/check-circle, chevron-down, search, plus, arrow-right, arrow-up-right, bell, heart?, loader (I'll do CSS spinner instead), calendar, more-horizontal, mail, user, layers, type, ruler?, box, credit... For sidebar nav I'll use mono numbers not icons. Keep icons minimal & functional. Let me draft the semantic token list: Colors semantic (light): - color-bg-canvas: #F7F4EE - color-bg-surface: #FFFFFF - color-bg-sunken: #EFEAE0 - color-bg-inverse: #201C17 - color-text-primary: #201C17 - color-text-secondary: #5D574B - color-text-muted: #8B8375 - color-text-inverse: #F7F4EE - color-border: #E3DCCC - color-border-strong: #C9C0AE - color-accent: #A8431F (action) - color-accent-hover: #8E3718 - color-accent-active: #7A2F14 - color-accent-subtle: #F6E7DC (tint bg) - color-accent-contrast: #FFFFFF - color-success: #2E6B45; success-subtle #E4F0E7? warm-tinted: #E6EFE4; success-text #24563A? just success token #2E6B45, subtle #E7F0E8 - color-warning: #8F5F00 (text-ish), warning-subtle #F6ECD4, warning-strong #B47A0A? Simplify: warning: #946200 ; warning-subtle: #F7EDD3 - color-danger: #B3321F; danger-hover #98281A; danger-subtle #F8E5E0 - color-info: #2A6072; info-subtle #E1EDF0 - focus ring: color-focus: #A8431F at 35%? Use rgba. Dark: - canvas #161310, surface #1E1A15, sunken #262119, inverse #F1EDE3 - text-primary #F1EDE3, secondary #B3AA9A, muted #7E7666 - border #332D24, border-strong #4A4336 - accent: #D57F4A, hover #E08F5C, active #C96F3C, subtle #33231A? accent-subtle in dark: rgba(213,127,74,0.14)? Use hex #3A2A1E. contrast text on accent: #1C1917 - success #6FBF8A? For dark: #71BF8F text-ish; success used as button bg? Mostly text/icon on subtle bg. success: #7CC193, subtle #1F2B21 - warning #E0A83E, subtle #2E2515 - danger #E36C55, hover #EC7F69, subtle #341D18 - info #6FA8BC, subtle #18262B Contrast demo pairs (light): text-primary/canvas, text-secondary/canvas, accent/white (on accent), success/success-subtle etc. I'll show ratio + grade chip. Compute dynamically so dark mode also recalculates — nice! When theme toggles, recompute contrast table. That's a strong craft signal: the doc itself validates its tokens in both themes. Buttons spec: - Height: sm 32, md 40, lg 48; padding-x: sm 12, md 16, lg 20; radius md (10px); font: body-sm 500 / body 500 / body 500... label 14/16. - Primary: bg accent, text accent-contrast; hover accent-hover; active accent-active + translateY(1px)?; focus ring 3px rgba accent .35 + 1px offset? Standard: box-shadow 0 0 0 3px canvas, 0 0 0 5px accent? Simpler: outline 2px offset 2px accent. I'll do focus-visible: outline: 2px solid var(--accent); outline-offset: 2px. - Secondary: bg surface, border 1px border-strong, text primary; hover bg sunken. - Ghost: transparent, text secondary→primary hover, bg subtle on hover. - Danger: bg danger text white; hover danger-hover. - Disabled: opacity? Better: bg border color, text muted, no events. I'll use reduced: bg sunken text muted border. - Loading: spinner replaces icon, disabled pointer. Also "icon button" square variant with lucide icon. Forms specifics: - Field: label 13px 600 (Instrument), optional hint 13 muted below input, focus: border accent + ring shadow 0 0 0 3px accent-ring (accent 20%). - Input: height 40, padding 0 12, radius 8? Use radius-sm 8. bg surface, border border-strong; hover border stronger. - Error: border danger, ring danger subtle on focus, message with alert icon 13px danger. - Success: border success, check icon inside right. - Textarea: min-height 96, counter bottom-right "0 / 280" live, turns warning >260, danger >280, blocks at 280 (maxlength). - Select: native with custom chevron via background-image SVG? Using wrapper with lucide chevron positioned; appearance:none. - Checkbox: 18px, radius 4, custom: appearance-none, checked bg accent with white check via clip-path or background SVG. Use inline SVG data-uri? Simpler: pseudo-element with borders forming checkmark (rotate trick). I'll use ::after with border-right/bottom rotate(-45deg). Indeterminate: ::before horizontal bar. Disabled: opacity. - Radio: 18px circle, checked dot via box-shadow inset or ::after. - Switch: 40×22 track, 18 knob, translate on checked, accent bg when on; label click toggles. - Demo form: name (required), email (format), role (select required), description (optional, counter), newsletter switch, terms checkbox required. Submit → validate all, scroll to first error, error summaries inline; on success: toast "Project created — all validations passed" and reset. Also a "reset" secondary button. Cards compositions: Grid 12 cols, gap 20: - Card A (span 7): article — image (picsum seed), tag chip, title (h3 Bricolage), excerpt, footer meta (avatar initials, date, read time) + arrow icon button. Hover: border-strong + shadow lift + image scale slightly. - Card B (span 5): metric — label, big number (Bricolage 40), delta chip (+12.4% success), sparkline SVG (path with area? simple stroke polyline, accent), footer note. Two stacked? One metric card + one "task/list" card stacked in the 5-col column: e.g., a compact list card with 3 rows (checkbox-like status dots, name, value) — that's real structure, not filler; it demos "list card". - Below: full-width horizontal card? Maybe a "profile/invite" card span 5 + quote card span 7? Careful not to overstuff. I'll do: row1: article(7) + metric(5). row2: list card (5) + quote/testimonial (7)? Hmm might be too much. Alternatively row2: one wide "banner-ish" card with action — a "trial expiry" style card with subtle accent bg and two buttons — shows CTA card. Let me do three distinct rows: 1. Article (7) | Metric (5) 2. Metric2? no. Row 2: List card (5) | CTA card (7) with sunken/accent-subtle bg, heading, text, primary+ghost buttons. This demos 4 card types asymmetrically. Sparkline: inline SVG polyline points hand-coded, with gradient fill? No gradient — use flat accent stroke + subtle accent fill at low opacity? A flat fill under line at 8% opacity is fine (not a decorative gradient). Or just stroke. I'll do stroke + small end dot. Tokens export: two tabs. tokens.css sample: ```css :root { /* Color · Semantic */ --color-bg-canvas: #F7F4EE; ... } [data-theme="dark"] { ... } ``` tokens.json sample with nested objects. Copy button per tab. Keep samples abbreviated but real (maybe 20-30 lines each). Toast: fixed bottom right (or bottom center on mobile), slide-up animation, icon + message + close, auto 3s, max stack. Now let me also add a subtle noise/texture? Maybe not — keep clean paper. Could add a very subtle radial vignette? Skip; hairlines carry it. Hero design: - Eyebrow: mono "MERIDIAN DESIGN SYSTEM — V1.0" - Giant heading in Bricolage: "Design that holds its line." or "One system. Every surface." Something memorable: "The quiet machinery behind the interface." Let me write: "A system of record for every pixel we ship." Hmm. Keep strong: heading "Built once. Shipped everywhere." Good. - Sub: short paragraph. - Meta row: 4 stats inline (not cards): "48 tokens · 3 typefaces? " Actually counts: tokens 60+, components 12, contrast AA+, themes 2. Render as a bordered inline strip. - Maybe hero right side: a specimen tile showing stacked tokens? Could do an interactive mini demo: theme toggle preview. Keep hero text-led with a decorative-but-meaningful element: a live "token strip" — a horizontal band of the primitive palette where hover expands swatch (flex-grow transition). That's a nice interactive flourish that is on-topic. I'll add the palette band at hero bottom: hovering a chip expands it and shows hex; click copies. Principles: numbered 01–04 with title + one-liner, in a 2-col asymmetric layout or vertical list with hairlines. Vertical list with big numerals left. Principles: 1. "Tokens before values" — No hardcoded decisions... 2. "Contrast is not negotiable" — AA minimum... 3. "Motion with manners" — 150–250ms... 4. "Few components, used well" ... Section header component: ``` 01 Color ... ``` With hairline top border and generous top padding, sticky? Not sticky. Sidebar nav items: 01 Overview / 02 Color / 03 Typography / 04 Spacing / 05 Buttons / 06 Forms / 07 Cards / 08 Export. Active: accent text + left marker bar. Also mini logo: a square mark — I'll draw a small SVG mark: concentric arcs / meridian lines — e.g., a circle with vertical ellipse lines (globe meridians). Simple: circle + 2 ellipses + horizontal line, stroke ink. Scrollspy with IntersectionObserver, rootMargin to trigger near top. Theme toggle: sun/moon icon button in topbar; also persist? localStorage might be blocked in sandboxed iframe (Artifacts). Use try/catch. Fine. Density toggle: segmented control "Comfortable | Compact" small; sets data-density, components use var(--pad-*). I'll wire input paddings, button paddings, card paddings to density vars. Copy function: ```js function copyText(t, label){ navigator.clipboard?.writeText(t).then(ok).catch(fallback) } ``` Fallback with textarea+execCommand. Contrast calc: ```js function lum(hex){...} function ratio(a,b){...} ``` Grades: >=7 AAA, >=4.5 AA, >=3 AA Large, else Fail. Display chip colored: success for pass, warning/danger for fail. Contrast rows to show (light values, computed live): - text-primary on bg-canvas - text-secondary on bg-canvas - text-muted on bg-canvas - accent on bg-canvas (as text/link) - accent-contrast on accent (button text) - success on success-subtle? maybe skip subtles; keep 5–6 rows. Add danger on canvas, text-inverse on bg-inverse. 6 rows good. Each row: two overlapping swatch circles (fg over bg), label, tokens in mono, ratio number big, grade chip. Compute on load + on theme change: I'll store rows with fg/bg token paths that read getComputedStyle from :root — since semantic vars flip with data-theme on , reading computed style of document.documentElement gives current values. Wait — data-theme should go on `` (documentElement) so vars apply globally including body bg. Yes, put data-theme & data-density on , toggled via JS. Default light. Toast icons via lucide: after dynamic insert need lucide.createIcons() again — call after adding toast, or use static SVG strings for toast icons. I'll call lucide.createIcons({attrs?}) after insertion — fine, it scans DOM. Or simpler: build toasts with inline SVG check/x/alert strings. I'll just call createIcons() after each insert (cheap enough). Spinner for loading button: CSS border spinner 14px. Let me now also ensure NO emoji anywhere, no gradients (careful with image overlay — for article card image, I might add a caption bar instead of gradient overlay; or use a solid scrim? Avoid gradients: use a solid chip below image, no overlay). Shadows: subtle, e.g. `0 1px 2px rgba(32,28,23,.06), 0 8px 24px -12px rgba(32,28,23,.12)`. Elevation tokens: - elev-0: none - elev-1: 0 1px 2px rgba(28,24,19,.05) - elev-2: 0 2px 4px rgba(...,.05), 0 8px 20px -8px rgba(...,.12) - elev-3: 0 4px 8px ..., 0 20px 40px -16px rgba(...,.2) Dark shadows: heavier black. Spacing visualization: rows: token name (mono), px value, bar (width = value×multiplier, height 12, bg accent for base 4? color-code: use ink bars with accent for "space-4 16px base unit"?) simple: bars in sunken ink at 12% with value label. Hover row highlights. Maybe show a demonstration box with padding applied? Keep bars + a "padding demo" box where clicking tokens applies? Extra. Keep bars clean + radius scale (squares with each radius) + elevation (3 sample tiles). Typography specimens: rows each: left meta column (token name mono, size/line metrics), right: sample text. Sizes from display-xl down to label. Sample strings vary. Border rows hairlines. Hover shows baseline? Could add toggle "show metrics" that overlays baseline grid lines on specimens — cute but scope. Skip. Variable playground: panel with big "Ag" or word "Meridian" specimen, sliders: Size? Just wght 200–800, wdth 75–100, opsz 12–96. Readout mono values + generated CSS line with copy. Sliders styled custom (accent thumb). Specimen text maybe user-editable (contenteditable) — nice touch: "click to edit". Also font stacks documented: display/ui/mono cards? Show as three "specimen plates": family name big, sample pangram, usage note, stack in mono. Layout: 3 plates but asymmetric widths (e.g., 5/4/3)? That's a 3-col but uneven — acceptable? "no uniform equal-width 3-column rows" — uneven spans + distinct content makes it fine. Or stack vertically: each family row full-width with big name left, sample right. Vertical rows feel editorial. I'll do rows: family row with big name, sample sentence, meta (weights, stack mono). 3 rows. Forms layout: two-column: left = anatomy & states (default/error/success/disabled field examples stacked), right = controls grid (checkbox, radio, switch, select, textarea). Then full-width demo form panel ("Project intake — live validation") below. Card section extras: annotation labels? Could add small mono captions above each card ("card / article · radius-lg · elev-1"). Nice spec-sheet touch. Export section: tabs styled as folder tabs, pre code with syntax? Hand-color with spans? Keep plain mono with muted comments — fine, or minimal highlighting via spans for selectors. Keep plain; content: tokens.css (~40 lines) & tokens.json (~35 lines). Footer: hairline, mono note "Meridian DS v1.0 — set in Bricolage Grotesque & Instrument Sans", link-less. Topbar: sticky, blur? bg canvas with bottom hairline; left: current section label (updates with scrollspy — nice alive detail), right: density segmented + theme icon button. Alright — mobile responsiveness: - ≤1024: sidebar hidden; main full width; topbar shows logo instead of section label. - Grids collapse to single column; button rows wrap; type scale rows stack meta above sample. - Hero heading clamp. Amount of code is large; that's fine. Let me be meticulous about details and write it. Let me define CSS custom properties structure: ```css :root{ /* primitives (constant) */ --pr-accent-50..900 (named --a50 etc? Use --accent-50 but primitives shouldn't flip; semantic flips. I'll name primitives --accent-100 etc. and semantic --color-accent etc.) ``` Primitives constant in :root; semantics in :root default light, overridden in html[data-theme="dark"]. Density vars: ```css :root{ --d-pad-sm:8px 12px; ... } ``` Simpler: define numeric vars: --ctrl-h-sm:32px; --ctrl-h-md:40px; --ctrl-h-lg:48px; --ctrl-px-sm:12px; --ctrl-px-md:16px; --ctrl-px-lg:20px; --field-h:40px; --card-pad:24px; --sec-gap:96px... compact: ctrl-h 28/34/40, px 10/12/16, field-h 34, card-pad 16, gaps reduced. Apply via [data-density="compact"]. Focus ring token: --ring-accent: 0 0 0 3px color-mix(in srgb, var(--color-accent) 22%, transparent). Use color-mix — supported in modern browsers. I'll use color-mix for subtle tints to keep tokens clean: accent-subtle = color-mix(accent 10%, canvas). But semantic token table needs hex values shown... If I use color-mix, computed style returns the mixed color — getComputedStyle will return resolved color (e.g., "rgb(...)"), which I can display. Actually that's fine and robust: display computed rgb→hex. But the token *value* string shown in doc should be authored hex ideally. Hmm. Simplify: author explicit hexes for subtle tints (as computed above) rather than color-mix, so docs show stable hex per theme. I'll hand-pick subtle hexes per theme. For focus ring alpha shadow, color-mix or rgba of accent — accent differs per theme, so use color-mix(in srgb, var(--color-accent) 20%, transparent). Modern browsers OK. Contrast chip grade colors: use success/warning/danger text on their subtle bg. Fonts loading: preconnect + css2 link. Icon list (lucide names): sun, moon, check, copy, x, chevron-down, arrow-right, arrow-up-right, alert-circle, check-circle-2? (use "circle-check" in new naming; lucide supports "check-circle-2" older / "circle-check" newer; unpkg latest uses new names like "circle-check", "alert-circle" → "circle-alert"? Lucide renamed: alert-circle → circle-alert, but aliases exist in the web build? The lucide web build (lucide.min.js) `createIcons` uses icon names in kebab-case of current names; old names may fail. To be safe use stable names: "check", "x", "copy", "sun", "moon", "chevron-down", "arrow-right", "arrow-up-right", "plus", "minus", "search", "calendar", "clock", "user", "users", "mail", "bell", "info", "triangle-alert"? (alert-triangle renamed triangle-alert). Risky ones I'll avoid or pin version. Better: pin version: https://unpkg.com/lucide@0.462.0 — then names are known: in 0.462, both aliases? Lucide dropped old aliases at some point (0.263+ had aliases deprecated but still present until v1?). Safer: use current canonical names: circle-alert, circle-check, triangle-alert, circle-info? Hmm "info" exists. Let me pin lucide@0.454.0 and use: sun, moon, check, x, copy, chevron-down, arrow-right, arrow-up-right, calendar, clock, circle-alert, circle-check, info, plus, heart? Not needed. "loader-circle" for spinner? I'll use CSS spinner. "chevrons-up-down" for select? chevron-down fine. "more-horizontal" → renamed "ellipsis" in newer versions. Avoid. Pin 0.454.0 and use canonical new names as of then: circle-alert ✓ (renamed in 0.365? Actually the big rename happened ~v0.365: AlertCircle→CircleAlert with aliases kept until v1). In 0.454 both work? Aliases were kept in JS package as deprecated aliases — in lucide web (umd) createIcons uses `icons` object keyed by PascalCase; data-lucide kebab matched. Aliases included? The umd build exports aliases too I believe. To minimize risk, I'll use names valid across versions: check, x, copy, sun, moon, info, plus, minus, search, mail, calendar, clock, user, users, bell, chevron-down, arrow-right, arrow-up-right — these are stable. For alert use "alert-circle"? If renamed... In 0.454.0, `alert-circle` still exists as alias (deprecated aliases removed in v1.0? The removal happened... lucide said aliases removed in 1.0; 0.x kept them). Pinning 0.454.0, alert-circle works. But to be extra safe I could inline my own SVGs for critical icons... That's heavy. Decision: pin `https://unpkg.com/lucide@0.454.0/dist/umd/lucide.min.js` and use: sun, moon, check, x, copy, info, alert-circle (alias ok), check-circle-2? — I'll use "circle-check" hmm. Use alias old names consistently: alert-circle, check-circle-2, x-circle? x-circle alias for circle-x. These old aliases existed for ages in 0.x. Choose: alert-circle, check-circle-2, x, copy, sun, moon, info, chevron-down, arrow-up-right, arrow-right, calendar, clock, users, plus, search. If any alias missing, icon silently missing — minor risk. Alternatively use always-canonical-both? "check-circle-2" was new name at some point then renamed circle-check... ugh. Safest: implement toast/notification icons as inline SVG strings I author myself (check circle, alert, info, x, copy) — full control. Use lucide only for static decorative/functional icons in markup (sun, moon, chevron-down, arrow-up-right, calendar, clock, users, plus, search, info, copy). Those names are ancient-stable except… "copy" stable, "sun/moon" stable, "info" stable, "chevron-down" stable, "arrow-up-right" stable (added long ago), "calendar" stable, "clock" stable, "users" stable, "plus" stable, "search" stable. Good — use unpkg latest? Pin anyway: lucide@0.454.0. And inline SVGs for toast icons. Custom toast markup: ```js const ICONS={success:'',error:'...',info:'...'} ``` Simple 16px stroke svgs. Now, hero palette band: chips with flex:1, hover flex-grow 2.2, overflow hidden, label shows on expand (opacity transition). Click copies hex + toast. Height ~64px, radius-lg, overflow hidden, hairline border. Chips: accent 200..800? Show accent scale 100–900 (9 chips). Text color per chip contrast (white or ink) — precompute classes: light chips (100–400) ink text; 500+ white text. On hover show name+hex vertical? horizontal centered mono 11px. On mobile band still fine. Also each chip title attr. Scrollspy sections: overview, color, typography, spacing, buttons, forms, cards, export. Topbar left shows "02 · Color" updating. Sidebar: logo mark + "Meridian" wordmark (Bricolage 700), "Design System v1.0" mono; nav list; bottom: theme note? Put theme + density controls in topbar right. Sidebar bottom: mono "48 tokens · 8 primitives?" counts: Let me count planned tokens: colors ~ 20 semantic + 34 primitives; type 12; space 9; radius 5; elevation 4 → total ~80. Say "80+ tokens". Buttons state matrix: a panel showing each variant in states using forced classes: .is-hover, .is-active, .is-disabled, .is-loading — styles mirror real pseudo via classes (I'll write CSS: .btn.primary:hover, .btn.primary.is-hover share selector list). Manageable: define styles with `:hover, .is-hover` grouped. Focus ring demo: show one with .is-focus (outline). Interactive area: buttons that respond; primary click → toast success "Primary action fired"; danger → confirm? no confirm() — danger click → toast error "Destructive action needs confirmation" then maybe turns into "Confirm?" state for 3s — nice microinteraction: danger button first click → text changes to "Confirm delete" with warning tone; second click → toast; revert after 3s. Memorable! Implement simply. Loading demo: button "Save changes" → click → loading state 1.8s → success check + toast → revert. Forms validation demo details: fields with data-validate. Email regex. On blur validate individual; on submit validate all; error msgs per field; aria-invalid; success toast + reset + also show inline success state briefly? Just toast + reset. Textarea counter coloring thresholds. Switch demo: label "Enable analytics" toggling a status pill text "on/off". Select custom chevron: wrapper .select with ::after? Use lucide icon absolutely positioned pointer-events none. Checkbox indeterminate: set via JS on load (el.indeterminate=true). Cards hover: transform translateY(-2px), shadow elev-2, border-strong; transition 180ms. Image: picsum seed e.g. `https://picsum.photos/seed/meridian7/640/360.jpg` (grayscale? add ?grayscale to fit palette! picsum supports `?grayscale` — with .jpg extension: https://picsum.photos/seed/meridian/640/360.jpg?grayscale — yes supported). Grayscale images keep palette cohesive — smart. Add slight sepia via CSS filter to warm it: filter: sepia(.18) contrast(1.02). Metric sparkline: svg viewBox 0 0 120 36 polyline points with stroke accent width 2, plus area path fill accent opacity .08? flat fill okay (solid, not gradient). End dot circle r2.5 fill accent. Numbers: use tabular-nums (Instrument Sans supports? has tnum? maybe; JetBrains for numbers anyway). Big metric number in Bricolage. List card rows: status dot (success/danger/warning), name, mono value, chevron? Keep: dot + text + time mono. 3 rows: "Deploy api-core — passed — 2m", "Nightly batch — running — 12s", "eu-west-1 probe — failed — 1m" — with colored dots. Row hover bg sunken. CTA card: bg sunken (or accent-subtle), left content (title, text) right buttons column? Horizontal: text left, buttons right. Radius-lg, maybe hairline border + accent-subtle bg. Title Bricolage. Export code content — write realistic: tokens.css: ```css /* Meridian Design Tokens — v1.0.0 */ :root { /* color · primitives */ --accent-100: #F7E3D5; ... (abbrev with a few) /* color · semantic */ --color-bg-canvas: #F7F4EE; ... /* typography */ --font-display: "Bricolage Grotesque", ...; --type-display-xl: 700 clamp(3rem,6vw,4.5rem)/1.05 ...;? tokens as separate: --text-display-xl: 4.5rem; --leading-tight:1.05; /* space */ --space-1: 4px; ... /* radius, elevation */ } [data-theme="dark"] { --color-bg-canvas:#161310; ... } ``` tokens.json: ```json { "$schema": "...", "color": { "bg": {"canvas": {"$value":"#F7F4EE","$type":"color"}, ...} } ``` Keep ~35 lines. Tabs JS: buttons toggling panels. Copy buttons on code blocks. Alright, also small components to enrich: badges/chips inside cards (tag on article, delta chip on metric) — inline styles via classes .chip variants. Alerts? skip section, toasts cover feedback. Let me think about total length — this will be a big file (~1500-1900 lines). That's fine. Now write CSS carefully with the design language: Global: ```css *{box-sizing:border-box;margin:0} html{scroll-behavior:smooth} body{background:var(--color-bg-canvas);color:var(--color-text-primary);font:400 16px/1.6 "Instrument Sans",sans-serif; -webkit-font-smoothing:antialiased} ::selection{background:color-mix(in srgb, var(--color-accent) 25%, transparent)} ``` Layout: ```css .app{display:grid;grid-template-columns:248px 1fr;min-height:100vh} .sidebar{position:sticky;top:0;height:100vh;border-right:1px solid var(--color-border);background:var(--color-bg-canvas); padding:28px 20px; display:flex;flex-direction:column} main{min-width:0} .container{max-width:1060px;margin:0 auto;padding:0 48px} ``` Topbar sticky within main. Section spacing: padding 88px 0, hairline top border except hero. sec-head: display grid: `grid-template-columns:64px 1fr; gap:24px; align-items:start; margin-bottom:40px`. Index in JetBrains mono 13px with accent? Index: mono, muted, with accent square marker? Style: index number with border chip? Keep: big-ish muted mono "02" plus thin rule extends? I'll do: index inside small bordered square (28px) mono, and next to heading small mono kicker "FOUNDATIONS". Design: ``` [02] COLOR ————— kicker line Color ... ``` Actually simpler elegant: top hairline; row: mono index left, right block: h2 + lede; between h2 and right edge a mono kicker aligned right "TOKENS · SEMANTIC + PRIMITIVE". Use flex space-between on the head row. Subsection headings: h3 with small mono anchor like "3.1 Scale". I'll add IDs and consistent classes. Let me now write everything. I'll be careful with escaping in code blocks: use < etc. where needed (CSS braces fine, `<` none). JSON has quotes fine. For the contrast table rows, build in JS from config: ```js const CONTRAST_ROWS=[ {fg:'--color-text-primary', bg:'--color-bg-canvas', label:'Body text on canvas'}, {fg:'--color-text-secondary', bg:'--color-bg-canvas', label:'Secondary text'}, {fg:'--color-text-muted', bg:'--color-bg-canvas', label:'Captions & metadata'}, {fg:'--color-accent', bg:'--color-bg-canvas', label:'Links & accent text'}, {fg:'--color-accent-contrast', bg:'--color-accent', label:'Text on primary action'}, {fg:'--color-text-inverse', bg:'--color-bg-inverse', label:'Inverse surfaces'}, {fg:'--color-danger', bg:'--color-bg-canvas', label:'Destructive text'}, ] ``` renderContrast() reads computed values, computes ratio, picks grade: ≥7 'AAA' pass, ≥4.5 'AA' pass, ≥3 'AA Lg' warn-ish pass, else 'Fail'. Chip classes. Also each row: dual swatch: outer circle bg with inner circle fg. getComputedStyle(document.documentElement).getPropertyValue('--color-accent') returns the var raw string including possible spaces — fine hex. But semantic accent in dark theme is defined; reading root computed gives resolved custom property string (the value as authored for current theme). Good — hex strings. hexToRgb handle 3/6. Ratio: (L1+0.05)/(L2+0.05). Grade chip colors: AAA/AA → success; AA Large → warning; Fail → danger. Re-render on theme toggle. Theme toggle also swaps icon (sun↔moon): easiest — two icons in button, CSS shows per data-theme. Toast function: ```js function toast(msg, type='success'){ ... region.appendChild(el); lucide? using inline svg; setTimeout remove with exit animation } ``` Max 4: remove oldest. Copy helper with clipboard API + fallback. Scrollspy: IO with rootMargin '-45% 0px -50% 0px' targeting sections; update sidebar links + topbar label. Also smooth scroll offset for sticky topbar: use scroll-margin-top on sections (88px). Variable playground sliders: input range styled: track hairline, thumb 16px circle ink with accent border? Custom styling for webkit/moz. Editable specimen: contenteditable="true" spellcheck=false, mono caret accent. Live CSS readout updates + copy button copies current string. Font faces: ensure Bricolage variable loads with axes; specimen uses font-variation-settings directly. Edge: setting font-variation-settings overrides weight; fine within playground only. Density toggle markup: two-button segmented: ```html ``` Better labels: "Default"/"Compact" small mono. Compact also reduces section padding? Just components. Actually also reduce container padding slightly. Keep components only. Compact values: --ctrl-h-sm:30px; md:36; lg:44; px 10/14/18; field-h 36; card-pad 18; chip sizes smaller. Comfortable defaults as above. Also apply to demo form paddings. Right — no gradient anywhere. Check shadows fine. Article image with filter sepia — good. Hero composition: ``` kicker row: mono "MERIDIAN — INTERNAL DESIGN SYSTEM" + right mono "V1.0.0 · UPDATED 2025" h1 huge: "Built once. Shipped everywhere." — em italic? Bricolage has no italic! Bricolage Grotesque has no italic axis (Google: ital? Bricolage has no italics). Use accent color for second line instead, or outline text? Solid: second line in accent? Big accent text might be loud; use accent only on a period or underline. Style: "Built once," line1 ink; line2 "shipped everywhere." with "shipped" in accent? Tasteful. Or second line in text-secondary lighter? I'll do: line1 ink "Built once." line2: "Shipped everywhere." with the final period in accent. Subtle signature. Hmm maybe make "everywhere." accent. Decide: `everywhere.` accent colored — one word accent is tasteful. lede paragraph max-width 560. meta strip: bordered inline list: TOKENS 80+ | COMPONENTS 9 | THEMES 2 · LIGHT/DARK | TARGET WCAG AA. As 4 cells with hairline dividers (flex row, wrap). palette band interactive (accent scale) with caption "Primitive · accent scale — hover to expand, click to copy". principles: h3 "Principles", numbered rows 01-04 with hairlines. ``` Principles rows: grid 72px 260px 1fr: number (mono, muted, large-ish 14), title (Bricolage 20 600), desc (secondary 15). Hairline bottom each. Hover: number turns accent. Typography section structure: 1. Family rows (3): display Bricolage / text Instrument Sans / mono JetBrains. Row layout: left: family name big Bricolage/mono sample + role chip; right: pangram at that family, meta line (weights, stack mono small). 2. Scale table (specimens). 3. Playground panel. Scale rows: token chip (mono, e.g., text-display-xl), meta (48/50 · 700 · -2%), sample right-aligned? Layout: grid 220px 1fr, sample baseline aligned; row padding 20 hairline. Samples: - display-xl: "Grand gestures" (44-72 clamp) — use fixed 3.5rem for doc? Use actual token size: 4.5rem might overflow; sample text short. - Use tokens: display-xl 4.5rem sample "Aa" + word? Sample "Rhythm & grid" might overflow at 72px in 1fr (~700px) — fits (approx 8 chars × 0.55em ≈ 316px) ok. - display 3rem "Considered defaults" - h1 2.25 "Sections that scan" - h2 1.75 "Labels carry weight" - h3 1.375 "Details, handled" - body-lg 1.125 sentence - body 1 sentence - body-sm 0.875 sentence - label 0.8125 uppercase tracking "OVERLINE · 11–13 PX" Meta column: name mono + specs mono muted "48px / 52 · 600". Spacing section: - spacing bars: token mono name, size label "4px", bar div width value*? scale ×2 for visibility? width: calc(var) direct px is fine (4px tiny but honest). Show also a usage hint. Bars: bg ink at 85%? Use --color-text-primary as bar color height 10 radius 2; hover accent. Row grid 140px 80px 1fr. - radius scale: row of squares 72px each with token label + value, bg surface border, radius applied, hover elev. - elevation: three tiles bg surface with elev-1/2/3, hover lift more? Static fine + labels. Also border token note. - Also motion tokens! durations & easings with a demo dot that animates on hover (or click "play"). Add mini: tokens duration-fast 120ms, base 180, slow 280; easing cubic-bezier(.2,0,0,1). Demo: three dots that translate on button "Run". Nice extra. Implement: click run → dots animate translateX with respective durations. Good alive detail. I'll include in spacing section as "Motion" sub-block. Buttons section layout: - Row: live playground: variant buttons all interactive + icon button + loading demo + danger confirm demo. - Sizes: sm/md/lg primary trio. - States matrix: table-ish: columns Variant / Default / Hover / Active / Focus / Disabled / Loading? Full matrix heavy; show per-variant row: primary & secondary rows with forced-state cells (Default, Hover, Focus, Disabled). Danger shown in live area. Keep matrix: rows primary, secondary, ghost; cells: default, hover(force), focus(force), disabled(force). Loading demoed live. Forms section: - "Anatomy" panel: one field large annotated? Use field with label/hint and mono annotation lines (leader lines complex — skip, use labeled stacked list): default, with hint, error, success, disabled — 5 stacked fields in left col. - Controls panel right: select, textarea w/ counter, checkbox group (with indeterminate parent), radios, switches (2), - Demo form panel full width. Cards section: grid as planned with mono captions. Export section: tabs + pre + copy. Footer. Toast region bottom-right. Okay writing code now. I'll be systematic. Also remember: no `#` heading start of response; brief explanation after code. Language: English. Some CSS details for chips (status): ```css .chip{display:inline-flex;align-items:center;gap:6px;height:24px;padding:0 10px;border-radius:999px;font:500 12px/1 ...} .chip.accent{background:var(--color-accent-subtle);color:var(--color-accent)} etc per tone. ``` Delta chip includes arrow icon (arrow-up-right small) — lucide inside dynamically? Static markup fine. Inputs: ```css .field{display:flex;flex-direction:column;gap:6px} .label{font:600 13px; color: text-primary} .label .req{color:var(--color-accent)}? required marker: accent asterisk. .hint{font:400 12.5px; color muted} .control{position:relative} .input, select.input, textarea.input{width:100%;height:var(--field-h);padding:0 12px;border:1px solid var(--color-border-strong);border-radius:var(--radius-sm);background:var(--color-bg-surface);color:var(--color-text-primary);font:400 14px "Instrument Sans";transition:border-color .15s, box-shadow .15s} .input::placeholder{color:var(--color-text-muted)} .input:hover{border-color:...} .input:focus{outline:none;border-color:var(--color-accent);box-shadow:0 0 0 3px color-mix(in srgb,var(--color-accent) 18%, transparent)} .field.error .input{border-color:var(--color-danger)} .field.error .input:focus{box-shadow danger mix} .field.error .msg{display:flex;gap:6px;color:var(--color-danger);font-size:12.5px} ``` Message hidden by default (display:none) shown via .show or field state class. Checkbox CSS: ```css .check{appearance:none;width:18px;height:18px;border:1.5px solid var(--color-border-strong);border-radius:5px;background:var(--color-bg-surface);display:grid;place-items:center;transition:...;cursor:pointer;flex:none} .check:hover{border-color:var(--color-accent)} .check:checked{background:var(--color-accent);border-color:var(--color-accent)} .check:checked::after{content:"";width:9px;height:5px;border-left:2px solid var(--color-accent-contrast);border-bottom:2px solid var(--color-accent-contrast);transform:rotate(-45deg) translate(0,-1px)} .check:indeterminate{background:var(--color-accent);border-color:var(--color-accent)} .check:indeterminate::after{content:"";width:8px;height:2px;background:var(--color-accent-contrast)} .check:focus-visible{outline:2px solid var(--color-accent);outline-offset:2px} .check:disabled{opacity:.4;cursor:not-allowed} ``` Radio similar with ::after dot scale transition. Switch: ```css .switch{position:relative;width:40px;height:22px;flex:none} .switch input{position:absolute;opacity:0;inset:0;cursor:pointer;margin:0} (keep input covering for a11y) .switch .track{position:absolute;inset:0;border-radius:999px;background:var(--color-border-strong);transition:background .18s} .track::after{content:"";position:absolute;top:2px;left:2px;width:18px;height:18px;border-radius:50%;background:#fff (var(--color-bg-surface)? knob white both themes: use #fff in light, in dark knob should be light too — bg-surface in dark is dark; use canvas? knob contrast: use var(--color-bg-canvas)? in light canvas cream — fine, in dark knob would be dark on dark track — bad. Use fixed #FFF knob with subtle shadow; in dark theme knob white on accent track fine; when off (track = border-strong dark gray) white knob fine.) box-shadow elev-1; transition:transform .18s cubic-bezier(.2,0,0,1)} input:checked + .track{background:var(--color-accent)} input:checked + .track::after{transform:translateX(18px)} input:focus-visible + .track{outline...} input:disabled + .track{opacity:.4} ``` Knob white constant — okay. Select: ```css .select-wrap{position:relative} .select-wrap svg{position:absolute;right:10px;top:50%;translate:0 -50%;pointer-events:none;color:var(--color-text-muted)} select.input{appearance:none;padding-right:34px;cursor:pointer} ``` Demo form validation JS: ```js const validators={ name: v=>v.trim().length>=2||'Enter at least 2 characters', email: v=>/^[^\s@]+@[^\s@]+\.[^\s@]+$/.test(v)||'Enter a valid email address', role: v=>!!v||'Choose a team', terms: (v,el)=>el.checked||'You need to accept the terms' } ``` Show/hide error: field wrapper .error class + msg text set. Blur validate; input clears error while typing; submit collects. Success: toast + form.reset() + counter reset + switch reset + remove states. Buttons JS: - [data-toast] click → toast(msg,type). - #btn-load: click → add .is-loading, disabled, after 1600ms → .is-done (show check + "Saved"), toast success, after 1200ms revert. - #btn-danger: state machine. Loading button: contains span.label + span.spinner; CSS .is-loading .spinner{display}. .is-done swaps label text via JS. Spinner: ```css .spinner{width:14px;height:14px;border:2px solid color-mix(in srgb,var(--color-accent-contrast) 35%,transparent);border-top-color:var(--color-accent-contrast);border-radius:50%;animation:spin .7s linear infinite;display:none} .is-loading .spinner{display:inline-block} ``` For ghost spinner color differs — only used on primary, fine. Icon button: 40×40 (sizes), ghost-style with border? variant: .btn.icon.secondary. Focus matrix cells: classes .is-hover/.is-active(no visual diff static? active slightly darker + inner translate—skip active col) columns: Default / Hover / Focus-visible / Disabled. Use .is-focus{outline:2px solid var(--color-accent);outline-offset:2px}. Now sidebar active link style: ```css .nav a{display:flex;gap:10px;align-items:baseline;padding:7px 10px;border-radius:8px;color:var(--color-text-secondary);font:500 13.5px;position:relative} .nav a .n{font:500 10.5px "JetBrains Mono";color:var(--color-text-muted);width:18px} .nav a:hover{color:var(--color-text-primary);background:var(--color-bg-sunken)? subtle} .nav a.active{color:var(--color-text-primary);background:var(--color-bg-surface);box-shadow:elev-1? or border} .nav a.active .n{color:var(--color-accent)} ``` Add left accent bar via ::before on active. Logo mark SVG: ```html ``` stroke ink 1.5. Put in 30px tile with accent bg? Mark: tile bg ink, strokes paper — strong. I'll do 30px rounded square bg var(--color-text-primary), strokes var(--color-bg-canvas). In dark flips automatically. Topbar: ```css .topbar{position:sticky;top:0;z-index:40;display:flex;justify-content:space-between;align-items:center;height:56px;padding:0 48px? within container width — make topbar full width of main with inner container. background:color-mix(in srgb, var(--color-bg-canvas) 88%, transparent);backdrop-filter:blur(8px);border-bottom:1px solid var(--color-border)} ``` Left: #crumb mono "01 · Overview". Right: seg + theme btn. Note: backdrop blur + semi-transparent canvas is fine (not a gradient). Contrast section markup container: `.contrast-list` rows built by JS. Swatch primitives rows: for each scale (accent, success? show accent full + neutrals? Show: Accent (9), Warm gray? we don't have gray scale primitives except semantic — add neutral scale primitives: - neutral: 50 #FAF8F3? Our paper family: - 50 #FBF9F4 - 100 #F5F1E8 - 200 #E9E2D3 - 300 #D8CFBB - 400 #B4A98F? hmm keep: 400 #B7AC93 - 500 #8F8672 - 600 #6C6454 - 700 #4E4739 - 800 #332E24 - 900 #201C15 Then semantic text/border map to neutrals. Good, doc shows Neutral + Accent + Success + Warning + Danger scales. 5 scale rows, each swatch row with click-copy. Success scale (green, hue ~145 desat): - 100 #E3EEE4 - 200 #C4DCC6 - 300 #9CC4A2 - 400 #6BA57A - 500 #478A5D - 600 #2E6B45 - 700 #245637 - 800 #194028 - 900 #102B1B Warning scale (ochre): - 100 #F5EBD0 - 200 #EAD9A8 - 300 #DCBF77 - 400 #C9A24C - 500 #B4862A? warning core ~ #B4862A; 600 #946A1D? Let me: 500 #B08424, 600 #8F6817 (usable as text), 700 #6F5111, 800 #503A0C, 900 #342507. And 300/400 for icons. Danger scale (oxblood hue 8): - 100 #F6E3DE - 200 #ECC6BC - 300 #DDA08F - 400 #CC7458? lean red: #CD6E52 - 500 #BC4A31 - 600 #A63420? earlier #B3321F computed contrast 6.19 — set 600 #B3321F, 500 #C6553D? Let me order: 400 #CE7B62, 500 #C24E33, 600 #B3321F, 700 #8F2617, 800 #671B10, 900 #40100A. And 300 #E09A87. Semantic mapping displayed in a two-col definition rows (grid 200px 1fr): token name mono + value chip (bg preview + hex mono) + usage note. ~16 rows grouped: Background (canvas/surface/sunken/inverse), Text (primary/secondary/muted/inverse), Border (default/strong), Accent (accent/hover/active/subtle/contrast), Status (success/warning/danger/info + subtle each). Group headers h4 mono. Value chip: inline-flex swatch square 16px + hex + copy on click. Row hover bg sunken. This doc is getting rich. Time to write. I'll write the code in one go, keeping careful organization and comments. One more check — "no rows of repeated identical cards": my typography family rows are full-width rows (fine); buttons matrix is a table (functional); color rows are lists (functional). Card section asymmetric. Principles rows list. Good. Also ensure interactions: keyboard focus styles everywhere (focus-visible accent outline). Dark-theme adjustments for specific components: code block bg — use sunken; syntax none. Chips subtle colors dark variants defined. Shadows in dark stronger alpha. Article image filter maybe brightness .9. Meta strip hero: cells with mono label small muted + value Bricolage 20. Wrap. Let me write JS carefully: ```js const $=s=>document.querySelector(s), $$=s=>[...document.querySelectorAll(s)]; // THEME const root=document.documentElement; function setTheme(t){root.dataset.theme=t;try{localStorage.setItem('mrd-theme',t)}catch(e){}renderContrast();} themeBtn onclick toggle. init from storage or prefers-color-scheme. // DENSITY seg buttons set root.dataset.density + .on class. persist try. // COPY async function copy(text,label){...toast(`${label} copied — ${text}`)...} // delegate clicks on [data-copy] document.addEventListener('click',e=>{const c=e.target.closest('[data-copy]');if(c){copy(c.dataset.copy, c.dataset.label||'Value')}}) ``` Swatches get data-copy=hex data-label=name. Toast: ```js const region=$('#toasts'); const ICONS={success:'', info: circle+i, error: circle+! } function toast(msg,type='success'){const t=document.createElement('div');t.className='toast '+type;t.innerHTML=`${ICONS[type]}${msg}`;region.appendChild(t);requestAnimationFrame(()=>t.classList.add('in'));const kill=()=>{t.classList.remove('in');t.classList.add('out');setTimeout(()=>t.remove(),240)};t.querySelector('.t-x').onclick=kill;setTimeout(kill,3400);while(region.children.length>4)region.firstChild.remove();} ``` CSS toast: fixed right 20 bottom 20, column gap 8; toast: bg inverse, text inverse, radius 10, padding 10 12, shadow elev-3, translateY(8px) opacity 0 → in. Icon color per type (success uses success color? On inverse bg use light tints: success #7CC193 etc. define --toast vars per type simple: color set inline classes .toast.success .t-ic{color:var(--color-success)...} in dark success var is light green good; in light success #2E6B45 on dark inverse bg — readable (contrast vs #201C17: ~? #2E6B45 vs dark bg: L 0.115 vs 0.0085 → (0.165)/(0.058)=2.8 low but it's an icon, ok-ish. Better use dedicated bright values regardless of theme: success icon #6FBF8A, error #E5765F, info #7FB4C9 fixed constants. Fine.) X button clears. Contrast render: ```js const rows=[...]; function renderContrast(){const cs=getComputedStyle(root);list.innerHTML=rows.map(r=>{const fg=cs.getPropertyValue(r.fg).trim(),bg=cs.getPropertyValue(r.bg).trim();const cr=contrast(fg,bg);const g=cr>=7?['AAA','ok']:cr>=4.5?['AA','ok']:cr>=3?['AA·Lg','warn']:['Fail','bad'];return `${r.label}${short(r.fg)} on ${short(r.bg)} ${cr.toFixed(2)}${g[0]}`}).join('')} ``` short: token → strip "--color-" prefix? Show raw token names mono small — fine as is but long; map to short names: replace('--color-','').replace('--',''). Scrollspy: ```js const spy=new IntersectionObserver(es=>{es.forEach(e=>{if(e.isIntersecting){const id=e.target.id;$$('.nav a').forEach(a=>a.classList.toggle('active',a.hash==='#'+id));$('#crumb').textContent=e.target.dataset.crumb;}})},{rootMargin:'-20% 0px -70% 0px'}); ``` data-crumb like "02 · Color". Playground: ```js const spec=$('#specimen'), sliders {wght,wdth,opsz}; function upd(){const w=..., d=..., o=...;spec.style.fontVariationSettings=`"opsz" ${o}, "wdth" ${d}, "wght" ${w}`;readout.textContent=`font-variation-settings: "opsz" ${o}, "wdth" ${d}, "wght" ${w};`;vals update} copy button copies readout. ``` Counter: ```js ta.addEventListener('input',()=>{const n=ta.value.length;counter.textContent=`${n} / 280`;counter.className= n>280?'over':n>240?'warn':''}) maxlength=280 anyway. ``` maxlength prevents >280; still color warn at 240+. Indeterminate: `$('#cb-parent').indeterminate=true;` parent toggles children; child changes update parent state — implement small logic. Switch status: on change update #sw-status text + class. Motion demo: three dots spans with classes; #run-motion button restarts: remove class, void offsetWidth, add .go. CSS: .dot{transition:transform var(--dur) var(--ease-out)} .go .dot1{transform:translateX(160px)} with per-dot duration via inline var. Actually set style.transitionDuration per dot from token values: fast 120, base 180? make visible diff: 150/300/500? Tokens: --dur-fast:120ms;--dur-base:200ms;--dur-slow:320ms;--ease-out:cubic-bezier(.2,0,0,1);--ease-spring:cubic-bezier(.34,1.3,.64,1). Dots use base with different? Use three dots each with different duration tokens — shows difference. And easing demo: two dots same duration different easing (out vs spring). Combine: row of 4 dots: fast/out, base/out, slow/out, base/spring. Danger confirm logic: ```js const db=$('#btn-danger');let armed=false,timer; db.onclick=()=>{if(!armed){armed=true;db.classList.add('armed');db.querySelector('span').textContent='Confirm delete';timer=setTimeout(reset,2600)}else{reset();toast('Item deleted — this was a demo','error'?) use type 'error' but message softened: 'Delete confirmed (demo)'}} function reset(){armed=false;clearTimeout(timer);db.classList.remove('armed');db.querySelector('span').textContent='Delete workspace'} ``` .armed style: bg danger hover darker? make it pulse? keep solid with slight shake? subtle: outline danger. Fine: same danger but with alert icon? Keep text change only + icon swap maybe. Simple. Form submit: ```js form.addEventListener('submit',e=>{e.preventDefault();let ok=true;for each field validate; if(!ok){first invalid focus; toast('Fix the highlighted fields','error')}else{toast('Project created — validation passed','success');form.reset();syncCounter;parent indeterminate reset; status text reset}}) ``` Also inputs clear error on input event. Card hover CSS + image filter. Code tabs: ```js $$('.tab').forEach(b=>b.onclick=...) toggle panels + .on. copy buttons with data-target reading textContent of code el. ``` lucide.createIcons() at end + after toasts not needed (inline svg). Also add keyboard: pressing "t" toggles theme? Gimmick maybe; add — subtle power feature, mention in footer? Could conflict with typing in inputs — guard e.target tagName. I'll skip to avoid surprise... actually it's a nice touch; guard properly (not in input/textarea/select/contenteditable). Add: keydown 't' theme, 'd' density? Keep just theme. Hmm, undocumented features confuse; add tiny hint in topbar? Skip keyboard shortcut. Fine. Hero palette band chips text color: compute once in JS? Precompute class in markup: chips 100-400 text ink, 500+ text paper. In dark theme primitives constant so fine. Now the semantic token "usage note" content — write concise real guidance. Also number formatting: ratio toFixed(2). Edge: getPropertyValue for vars defined with fallback none returns "" if undefined — all defined. hex may include spaces — trim. Contrast func: ```js function hexRgb(h){h=h.replace('#','');if(h.length===3)h=[...h].map(c=>c+c).join('');const n=parseInt(h,16);return[(n>>16)&255,(n>>8)&255,n&255]} function lum(h){const[r,g,b]=hexRgb(h).map(v=>{v/=255;return v<=.03928?v/12.92:Math.pow((v+.055)/1.055,2.4)});return .2126*r+.7152*g+.0722*b} function ratio(a,b){const l1=lum(a),l2=lum(b);return (Math.max(l1,l2)+.05)/(Math.min(l1,l2)+.05)} ``` Now writing the whole file. I'll aim for clean, commented, organized code. Also remember start response without # heading, first-person intro, then code block, then brief explanation. Let me draft the tokens.css sample content (abbreviated but consistent): ``` /* ============================================ MERIDIAN — Design Tokens v1.0.0 ============================================ */ :root { /* — Color · primitives (do not use directly) — */ --accent-100: #F7E3D5; --accent-300: #E2A277; --accent-500: #C25E2B; --accent-600: #A8431F; --accent-700: #86351A; --neutral-100: #F5F1E8; --neutral-300: #D8CFBB; --neutral-600: #6C6454; --neutral-800: #332E24; --neutral-900: #201C15; /* — Color · semantic (use these) — */ --color-bg-canvas: #F7F4EE; --color-bg-surface: #FFFFFF; --color-bg-sunken: #EFEAE0; --color-text-primary:#201C15; --color-text-secondary:#5D574B; --color-text-muted: #8B8375; --color-border: #E3DCCC; --color-border-strong:#C9C0AE; --color-accent: #A8431F; --color-accent-hover:#8E3718; --color-accent-subtle:#F4E4D7; --color-success: #2E6B45; --color-warning: #8F6817; --color-danger: #B3321F; --color-info: #2A6072; /* — Typography — */ --font-display: "Bricolage Grotesque", "Instrument Sans", sans-serif; --font-text: "Instrument Sans", system-ui... hmm avoid system-ui in doc? it's a fallback stack — acceptable in code sample; fine, fallbacks are pragmatic. I'll write fallback: sans-serif. --font-mono: "JetBrains Mono", monospace; --text-display-xl: 4.5rem; --leading-display: 1.05; --text-h1: 2.25rem; --leading-title: 1.2; --text-body: 1rem; --leading-body: 1.6; --text-label: 0.8125rem; --weight-regular: 400; --weight-semibold: 600; --weight-bold: 700; /* — Spacing (4px base) — */ --space-1: 0.25rem; /* 4 */ --space-2: 0.5rem; /* 8 */ --space-3: 0.75rem; /* 12 */ --space-4: 1rem; /* 16 */ --space-5: 1.5rem; /* 24 */ --space-6: 2rem; /* 32 */ --space-7: 3rem; /* 48 */ --space-8: 4rem; /* 64 */ --space-9: 6rem; /* 96 */ /* — Radius & elevation — */ --radius-sm: 8px; --radius-md: 12px; --radius-lg: 20px; --radius-full: 999px; --elev-1: 0 1px 2px rgb(32 28 21 / .06); --elev-2: 0 2px 4px rgb(32 28 21 / .05), 0 10px 24px -10px rgb(32 28 21 / .14); --elev-3: 0 4px 10px rgb(32 28 21 / .08), 0 24px 48px -16px rgb(32 28 21 / .22); /* — Motion — */ --dur-fast: 120ms; --dur-base: 200ms; --dur-slow: 320ms; --ease-out: cubic-bezier(.2, 0, 0, 1); } [data-theme="dark"] { --color-bg-canvas: #161310; --color-bg-surface:#1E1A15; --color-bg-sunken: #262119; --color-text-primary:#F1EDE3; --color-text-secondary:#B3AA9A; --color-text-muted:#7E7666; --color-border:#332D24; --color-border-strong:#4A4336; --color-accent:#D57F4A; --color-accent-hover:#E08F5C; --color-accent-subtle:#3A2A1E; --color-accent-contrast:#1C1917; --color-success:#7CC193; --color-warning:#E0A83E; --color-danger:#E36C55; --color-info:#6FA8BC; } ``` tokens.json similar nested. Keep each ~45 lines max. Wait, earlier I defined light accent-subtle as #F6E7DC vs export #F4E4D7 — unify: #F5E5D8. And I should ensure semantic values in doc table match export. I'll finalize values: LIGHT: - bg-canvas #F7F4EE - bg-surface #FFFFFF - bg-sunken #EFEAE0 - bg-inverse #201C15 - text-primary #201C15 - text-secondary #5D574B - text-muted #8B8375 - text-inverse #F7F4EE - border #E3DCCC - border-strong #C9C0AE - accent #A8431F - accent-hover #8E3718 - accent-active #7A2E13 - accent-subtle #F5E5D8 - accent-contrast #FFFFFF - success #2E6B45, success-subtle #E7F0E6 - warning #8F6817, warning-subtle #F6EDD2 - danger #B3321F, danger-hover #962716, danger-subtle #F7E3DC - info #2A6072, info-subtle #E2EEF1 - focus-ring: color-mix accent 20% DARK: - bg-canvas #161310 - bg-surface #1E1A15 - bg-sunken #262119 - bg-inverse #F1EDE3 - text-primary #F1EDE3 - text-secondary #B3AA9A - text-muted #807867 - text-inverse #161310 - border #332D24 - border-strong #4A4336 - accent #D57F4A - accent-hover #E08F5C - accent-active #C96F3C - accent-subtle #3A2A1E - accent-contrast #201C15 - success #7CC193, subtle #1F2B21 - warning #E0A83E, subtle #2E2515 - danger #E36C55, hover #EC8169, subtle #361D17 - info #6FA8BC, subtle #18262B Semantic table rows will show these with copy. Contrast checks sanity (dark): text-secondary #B3AA9A on #161310: L1? approx (179,170,154): roughly L≈0.41 → ratio (0.46)/(0.0567)? compute-ish: fine >7. muted #807867 on canvas: (128,120,103) L≈0.19 → (0.24)/(0.0567)=4.2 — AA Large-ish, muted text at small sizes borderline; acceptable as caption tone, or lighten muted to #8A8172 (~ratio 4.8). Use #8A8172 dark muted. Light muted #8B8375 on #F7F4EE: L muted? (139,131,117): linear ≈ R .264? compute: 139/255=.545→((.6)/1.055=.5688)^2.4? ln .5688=-.5643×2.4=-1.354→.2582; G .5137→(.5390)^2.4: ln -.6178×2.4=-1.4827→.2271; B .4588→(.4870)^2.4: ln-.7196×2.4=-1.727→.178. L=.2126×.2582+.7152×.2271+.0722×.178=.0549+.1624+.0129=.2302. Canvas #F7F4EE L≈? (247,244,238): ~.905? approx .90. ratio=(0.95)/(0.2802)=3.39 — muted fails AA normal (it's for captions ≥ maybe fine but flagged "AA·Lg"). To get AA, darken muted: #756D5F: (117,109,95): .4588→? compute-ish L≈0.155 → ratio 0.955/0.205=4.66 ✓. Let me set light text-muted #756D5F? But visually muted should be lighter... #7A7264: (122,114,100) L? R .4784→(.5057)^2.4: ln -.6818*2.4=-1.636→.1947; G .4471→(.4759)^2.4: ln -.7427×2.4=-1.7824→.1682; B .3922→(.4239)^2.4: ln -.8583×2.4=-2.06→.1275. L=.2126*.1947+.7152*.1682+.0722*.1275=.0414+.1203+.0092=.1709. ratio=.955/.2209=4.32 — close. #746C5E gives ~4.7. Choose muted #736B5D. Hmm but then secondary vs muted gap: secondary #5D574B ratio? (93,87,75): R .3647→(.3978)^2.4: ln -.9222×2.4=-2.213→.1093; G .3412→(.3755)^2.4: ln -.9794×2.4=-2.3505→.0953; B .2941→(.3309)^2.4: ln -1.106×2.4=-2.654→.0703. L=.2126*.1093+.7152*.0953+.0722*.0703=.0232+.0682+.0051=.0965. ratio=.955/.1465=6.52 ✓. So: secondary #5D574B (6.5:1), muted #736B5D (~4.7:1) ✓ AA. Dark muted #8A8172 ratio: (138,129,114): L? R .5412→(.5651)^2.4: ln -.5707×2.4=-1.3697→.2542; G .5059→(.5316)^2.4: ln -.6319×2.4=-1.5166→.2195; B .4471→.1682. L=.2126*.2542+.7152*.2195+.0722*.1682=.054+.157+.0121=.2231. vs canvas dark L .0067: ratio .2731/.0567=4.82 ✓. Accent as text on light canvas: #A8431F L=.1243 → ratio .955/.1743=5.48 ✓ AA. Dark accent #D57F4A L=.2982 on #161310: .3482/.0567=6.14 ✓. danger #B3321F on canvas: L=.1197 → .955/.1697=5.63 ✓. dark danger #E36C55: (227,108,85): R .8902→(.8959)^2.4: ln-.1099×2.4=-.2638→.7681; G .4235→(.4536)^2.4: ln-.7905×2.4=-1.897→.15; B .3333→(.3681)^2.4: ln-.9994×2.4=-2.3986→.0909. L=.2126*.7681+.7152*.15+.0722*.0909=.1633+.1073+.0066=.2772. ratio=.3272/.0567=5.77 ✓. Great — all pass; contrast table will show AA/AAA passes which reinforces credibility. Neutral primitives finalize: ``` --neutral-50:#FBF9F4;100:#F5F1E8;200:#E9E2D3;300:#D8CFBB;400:#B7AC93;500:#8F8672;600:#6C6454;700:#4E4739;800:#332E24;900:#201C15 ``` Accent primitives: 50 #FBF2EB,100 #F7E3D5,200 #EEC6AB,300 #E2A277,400 #D57F4A,500 #C25E2B,600 #A8431F,700 #86351A,800 #5F2512,900 #3D170B. Hero band shows accent 100–900. Type scale tokens: display-xl 4.5rem/1.02? set 1.04; display 3rem/1.08; h1 2.25/1.15; h2 1.75/1.25; h3 1.375/1.35; h4 1.125/1.4; body-lg 1.125/1.6; body 1/1.6; body-sm .875/1.5; label .8125/1.2 caps .08em. Spacing tokens: space-1..9: 4,8,12,16,24,32,48,64,96. Component-level tokens: --ctrl-* as planned. Radius: sm 8, md 12, lg 20, xl 28?, full 999. Cards use lg, buttons md? Buttons radius: 10 — that's between; add --radius-btn? Use md 12 for buttons? Buttons at 12 look pill-ish at 40h — fine modern. Inputs 10? Keep: inputs/buttons radius 10 = --radius-md 10? Redefine: xs 6 (chips small), sm 8 (inputs), md 12 (buttons, cards?), lg 20 (large cards, panels), full. Buttons md 12? At h40 r12 chunky nice. OK: xs6 sm8 md12 lg20 full999. Panels/docs cards lg. Inner cards md? Cards section cards: lg. Elevation tokens as above. OK — also "Buttons" doc includes spec side notes: mono annotations like "h 40 · px 16 · r 12 · text 14/600". Add tiny spec caption under each demo row. Nice spec-sheet vibe. Now write final HTML. I'll write with care; length ~ big but let's go. I'll organize CSS with section comments. Also topbar crumb initial "00 · Overview"? sections data-crumb: overview "01 · Overview" etc. Sidebar numbering 01–08 matching. Let me also handle small-screen topbar: show logo mini instead of crumb? Keep crumb, fine. Media queries: - max-width 1100px: hide sidebar (.app{grid-template-columns:1fr}); - max-width 720px: container padding 20px; hero h1 clamp handles; meta strip wrap; grids single col (.grid-12 → block with gap); buttons rows wrap; anatomy grids single; type rows stack; sec-head stack; topbar padding 16; contrast rows wrap; playground specimen font-size clamp. Card grid: use CSS grid 12: .cards{display:grid;grid-template-columns:repeat(12,1fr);gap:20px} spans .s7{grid-column:span 7} etc. Collapse at 900: all span 12. Forms two-col: .split{display:grid;grid-template-columns:1fr 1fr;gap:28px} collapse 860. Playground layout: panel bg sunken radius lg padding 28: top specimen area (bg surface? keep sunken, specimen huge ink), bottom controls row: 3 slider groups + readout. Sliders grid 3 col collapse 1. Range styling: ```css input[type=range]{-webkit-appearance:none;width:100%;height:22px;background:transparent;cursor:pointer} input[type=range]::-webkit-slider-runnable-track{height:2px;background:var(--color-border-strong)} input[type=range]::-webkit-slider-thumb{-webkit-appearance:none;width:14px;height:14px;border-radius:50%;background:var(--color-accent);margin-top:-6px;border:none;box-shadow:0 0 0 2px var(--color-bg-canvas)? keep simple} ::-moz-range-track / thumb similarly. ``` Specimen text: "Meridian" default? Use "Aa Bb"? Use word "Grid & rhythm"? Editable: default "Rhythm". Font-size clamp(3rem,8vw,5.5rem). Show baseline hairline under. Readout mono small + copy icon button. Also sliders labeled mono: WGHT 700 / WDTH 100 / OPSZ 96 with value spans. Contrast list markup styling: rows grid: swatch 40px, meta 1fr, ratio 64px right mono big, chip 70px. Hairline dividers. crow swatch: 36px circle border hairline, inner circle 18px centered. Buttons section layout: Panel A (live): flex wrap gap 12: primary, secondary, ghost, danger(+confirm), icon-btn(search), loading(save). Below caption mono spec. Panel B sizes: three primaries sm md lg. Panel C matrix: table via grid: header row mono labels; rows: variant name mono + 4 cells. Cells: buttons forced classes, non-interactive (pointer-events none, tabindex -1? set disabled? disabled changes style—use pointer-events:none and aria-hidden). Matrix CSS reuse: .btn.is-hover{...same as hover} etc. Write selectors: ```css .btn.primary:hover,.btn.primary.is-hover{background:var(--color-accent-hover)} .btn.primary:active,.btn.primary.is-active{background:var(--color-accent-active);transform:translateY(1px)} .btn:focus-visible,.btn.is-focus{outline:2px solid var(--color-accent);outline-offset:2px} ``` etc per variant. Ghost hover: bg sunken? bg: color-mix accent 8%? Use sunken. Secondary hover: border-strong + bg sunken slight. .btn base: ```css .btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;height:var(--ctrl-h-md);padding:0 var(--ctrl-px-md);border-radius:var(--radius-md);border:1px solid transparent;font:600 14px/1 "Instrument Sans";letter-spacing:.01em;cursor:pointer;transition:background var(--dur-fast) var(--ease-out),border-color var(--dur-fast),color var(--dur-fast),transform var(--dur-fast);user-select:none;white-space:nowrap} .btn:disabled,.btn.is-disabled{cursor:not-allowed;pointer-events:none} ``` Disabled styles per variant: use generic: opacity? Style: primary disabled: bg sunken? Let me: .btn.primary.is-disabled{background:var(--color-bg-sunken);color:var(--color-text-muted)} secondary disabled similar border default color muted. Simpler: all disabled: background:var(--color-bg-sunken); color:var(--color-text-muted); border-color:transparent (secondary keeps border var border). ok: ```css .btn:disabled{background:var(--color-bg-sunken)!important;border-color:var(--color-border)!important;color:var(--color-text-muted)!important;box-shadow:none!important} ``` Use :disabled only (force via disabled attr in matrix). matrix disabled cell: actual disabled attr — perfect, no class needed. Sizes: .btn.sm{height:var(--ctrl-h-sm);padding:0 var(--ctrl-px-sm);font-size:13px;border-radius:8px} .lg{height:var(--ctrl-h-lg);padding:0 var(--ctrl-px-lg);font-size:15px} Icon btn: .btn.icon{width:var(--ctrl-h-md);padding:0} svg 18. svg size: lucide default 24 — set via CSS `.btn svg{width:16px;height:16px}` and global `svg{display:block}`? Lucide replaces with svg keeping classes? It copies attributes. I'll size via CSS selectors on container: e.g., `.meta-ic svg{width:13px;height:13px}` etc. Set default: `.lucide{width:16px;height:16px;stroke-width:1.8}`? lucide adds class "lucide". I can globally style svg.lucide. Good: ```css svg.lucide{width:16px;height:16px} ``` then override where needed. Ghost spinner not needed. Now card article: ```html Engineering Designing the Meridian grid How a 4-point spacing system and 12-column grid keep product surfaces consistent from marketing site to console. AK Aiko KimuraJun 12 · 8 min read ``` chip overlay on image: positioned top-left with solid bg (surface) to avoid gradient scrim. Metric card: ```html Weekly active teams12.4% 2,847 vs. 2,532 last week · source:metrics.api ``` spark CSS: .line{fill:none;stroke:var(--color-accent);stroke-width:2;vector-effect? fine} .fill{fill:var(--color-accent);opacity:.07} .dot{fill:var(--color-accent)}. List card: ```html Deploys today api-core v2.14.0production · canary 10% 2m ... "web-app v1.9.2" staging · building now "edge-worker v0.3" failed · rolled back 41m ``` dots: 8px circles colored success/info/danger; run could pulse animation (opacity) — alive detail. CTA card: ```html Migrate your tokens tonight Run meridian sync to pull the latest token release into every product repo. Rollback is one command away. ``` cta bg accent-subtle border accent 25%? border color-mix accent 30%, transparent. text primary. Cards captions above each: mono 11 muted uppercase: "CARD / ARTICLE — R-LG · ELEV-1". Forms demo form ids: f-name, f-email, f-role, f-desc, f-switch, f-terms. Validation messages predefined in markup .msg spans with text; toggle .show on field.error. For terms (checkbox) error message below group. Also add success state example: input with check icon (position absolute right) — static example "Valid" state. Anatomy examples column entries: 1. Default — label "Display name" placeholder "Aurora console" 2. With hint — hint "Visible to teammates only." 3. Error — value invalid "aurora@" msg "Enter a complete email address." 4. Success — value "aiko@meridian.dev" + check icon 5. Disabled — value "Locked field" disabled Controls column: - Select "Team" options - Textarea "Project brief" counter - Fieldset checkboxes: parent "Notify me" indeterminate + children Email/Slack checked one - Radios: "Environment" staging/production - Switches: "Usage analytics" on; "Beta features" off — with status pill live for first. Density compaction also on fields via --field-h. OK writing now. Also add `scroll-margin-top:72px` on sections. One more consideration: overall page top: main contains topbar sticky; hero starts below. Footer content: hairline top, flex: left "Meridian Design System · v1.0.0 — crafted as a single-file reference." right mono "BRICOLAGE GROTESQUE / INSTRUMENT SANS / JETBRAINS MONO". Time to produce final code. I'll write ~ carefully ensuring all JS ids match. Also double-check no emoji, no gradients (image? none), no lorem, everything wired. For the exports `` content, escape nothing special except keep `&` none. JSON quotes fine. Let me also make sure buttons inside forms default type="button" to avoid submits (demo form submit button is type submit; others specify type). Toast width ~ 320; on mobile right 12 left 12. Write the code: Also nav anchor click: default anchor jump with scroll-behavior smooth + scroll-margin handles offset. Sidebar links href="#id". Active default: overview. Potential pitfall: IntersectionObserver with rootMargin percentages relative viewport — good. Density: compact reduces --ctrl sizes AND --card-pad AND --field-h AND .panel padding var? Panels use fixed paddings; wire --panel-pad var: comfortable 24, compact 18. And section padding stays. Also segmented control styling. Also topbar theme button: 32px ghost icon button. Let me write everything now, mindful of correctness. For lucide script: place before my script or use defer; call createIcons on DOMContentLoaded / at end. Final check on avoiding banned things: no gradients (spark fill is flat), no emoji, custom fonts ✓, no alert() ✓, images only picsum grayscale ✓, no lorem ✓, dark toggle ✓, asymmetric layout ✓. Write it. Rough estimate of contrast row token short names: e.g. "--text-primary on --bg-canvas". For code sample in export: include comment header lines; ensure no `<` chars. JSON has `{` fine. In tokens.json sample use $value/$type schema-ish (W3C design tokens format) — realistic. Now produce final answer: short intro (first person, plan), the single HTML code block, then brief explanation of implementation. Intro should mention assumptions (neutral SaaS, tokens + components doc, light/dark, interactions). Let me write out all code now in final form. I'll be careful with the CSS var names consistency. Define in :root: ```css /* primitives */ --accent-50..900, --neutral-50..900, --success-100..900? To keep file shorter, primitives for status scales: define 100,300,500,600,700,900 for success/warning/danger? Doc swatch rows need the values listed in JS/markup anyway; CSS needs only used ones. I'll define full accent+neutral, and for status scales define the swatch data in markup (chips styled inline background style attr) — primitives don't need CSS vars at all for display! Swatch chips can use inline style="background:#...". Good — less CSS. But copy needs hex: data-copy attr. So primitive swatches are pure markup. Semantic vars needed in CSS: define both themes fully. ``` Semantic tokens CSS (light + dark) as listed. Component tokens in :root (density). Global resets, layout, topbar, sidebar, sections, hero, principles, band, subsections... let me just write. For .value-chip (semantic rows): ```html ``` Hover shows copy icon. Rows: grid: 190px(token name) 1fr(note) 150px(chip). Token name mono 12.5 accent-ish? token name in mono color text-primary weight 500, note secondary 13.5. Group titles: h4 mono 11 uppercase muted letterspacing with count. Primitive scale row: ```html accentPrimary action hue · terracotta 9 buttons.step style bg, data-copy ``` .step{flex:1;height:56px;display:flex;align-items:flex-end;justify-content:center;padding-bottom:6px;font mono 10;opacity 0→hover 1; first radius left, last right} band-like same as hero (reuse .band component!) Hero band = accent steps; color section reuses for all 5 scales. Text color: for steps with light bg need ink text — per-step inline style color too. I'll compute manually: accent: steps1-4 ink,5+paper? 500 #C25E2B with white text contrast 4.38 large-only — label is tiny... show hex only on hover at 10px — decorative; use white on 500+ anyway, ink on ≤400. success: ≤400 ink. warning: ≤400 ink (500 #B08424 white? contrast (176,132,36): L? ~0.27 → 3.3 low; use ink text on ≤500, white 600+). danger: ≤400 ink. neutral: ≤300 ink, 400 #B7AC93 white? contrast (183,172,147) L≈0.43 vs white 2.0 — use ink on ≤400? white on 500 #8F8672 (L .23? ratio ~3.5) meh ink on ≤400, white 500+. Fine—decorative hover labels. Actually simpler: label positioned below on hover? Keep inside. Number the steps with index? show "600" + hex on hover: content "600 · #A8431F" tiny. At 56px height, 10px font ok. Default state shows just step number? Show nothing default, hover shows full. Add title attr. Hero band reuse: .band{display:flex;height:64px;border-radius:var(--radius-lg);overflow:hidden;border:1px solid var(--color-border)} .band .step:hover{flex-grow:2.4} transition flex-grow .25s ease-out — flex-grow transition works (animatable). Spacing bars color: background:var(--neutral-800)? use text-primary. Hover accent. Radius tiles: 64px squares bg surface border, radius each; label under mono. Elevation tiles: 120×84 bg surface radius md with elev classes; page bg canvas so visible. Also border hairline. Motion: tokens list + stage: 4 lanes each: label mono (fast·out / base·out / slow·out / base·spring) + track with dot; Run button. Dot animation via class .go with per-dot transition-duration/easing from inline style or classes: ```css .dot-m{width:18px;height:18px;border-radius:50%;background:var(--color-text-primary);transition:transform 0ms} .go .d1{transform:translateX(calc(100% ...))} need track width: track flex-1 position relative; dot absolute left 0; translateX(var(--dist,200px)) — set --dist via JS to track.clientWidth - 26. Do JS: on run, set each dot style.transition='transform var(--dur) var(--ease)' using token map, set transform translateX(dist). Reset after. Implement fully in JS with tokens {fast:120...}. Dot color: last one accent to distinguish spring? all ink, fine. ``` Simplify JS: ```js function runMotion(){const dist=track.clientWidth-30;laneDots.forEach((d,i)=>{d.style.transition='none';d.style.transform='translateX(0)';});requestAnimationFrame(()=>{requestAnimationFrame(()=>{dots.forEach((d,i)=>{const cfg=[['120ms','cubic-bezier(.2,0,0,1)'],['200ms','cubic-bezier(.2,0,0,1)'],['320ms','cubic-bezier(.2,0,0,1)'],['200ms','cubic-bezier(.34,1.4,.64,1)']][i];d.style.transition=`transform ${cfg[0]} ${cfg[1]}`;d.style.transform=`translateX(${dist}px)`})})})} ``` Good. Now finalize form demo submit behaviors & button demos. Also add `aria` labels where sensible (roles minimal). Let me now write the final file text. I'll keep class names short. Begin. Also hero H1 size: clamp(2.8rem, 5.4vw, 4.6rem), Bricolage 700, letter-spacing -0.035em? Bricolage already tight; -0.02em. Sec h2: clamp(1.9rem, 3vw, 2.4rem) Bricolage 650? weight 640? use 640? font-weight numeric fine for variable: 640 ok but keep 600/700 standards: 600. Also give body Instrument Sans; buttons/labels Instrument; mono JetBrains. Potential issue: Bricolage Grotesque Google variable requires specifying axes in URL as I wrote; also default opsz auto. In specimens headings set font-variation-settings? Let opsz auto (font-optical-sizing:auto default). Good. Write code now. (Also remember `overflow-x:hidden` maybe for band? contained.) For the matrix grid: columns: 110px repeat(4, 1fr)? cells contain buttons; wrap scroll-x on small: wrap in .table-scroll{overflow:auto}. Let me count sections crumbs: 01 Overview,02 Color,03 Typography,04 Spacing & motion,05 Buttons,06 Forms,07 Cards,08 Export. Also the demo form panel header row: title + mono "INTERACTIVE — VALIDATION LIVE". Ready. Writing final. One more: prefers-color-scheme initial: if no stored, match dark? default light to show paper aesthetic first. Use stored else 'light'. Toast text ensure no injection issues — fine. Also add "skip" small helper? no. Alright, code: I'll now carefully compose. Given size, stay organized. Also ensure data-copy on vchips uses actual values matching CSS. Semantic token table rows list (light values shown in markup; values differ in dark but chip shows authored light hex — hmm, chip shows static hex but swatch color should reflect current theme! Make chip swatch use CSS var background (var(--color-accent)) so it flips, and the hex code text shows light value... mismatch in dark. Solution: JS updates the hex text on theme change: give each vchip data-var="--color-accent"; on theme toggle, loop vchips: read computed var, set code text + data-copy. That keeps docs truthful in both themes — excellent craft. Implement renderSemanticValues() on theme change. For primitives (constant) static fine. So semantic rows: ` Meridian — Product Design SystemV1.0.0 · 2025 Edition Built once. Shipped everywhere. Meridian is the working source of truth for our interface: a token set, a type system, and nine components that stay consistent from the first click to the thousandth. This page is the spec — and it's built entirely from the system it documents. Design Tokens80+ Components9 Themes2 Densities2 Contrast TargetAA Primitive · Accent Scale — Hover to expand · Click to copy Operating Principles 01Tokens before values Every color, size and duration is named once and referenced everywhere. If a literal value appears twice in the codebase, one of them is already wrong. 02Contrast is non-negotiable Body text ships at AA or better in both themes. The palette is engineered around accessibility from the start, not audited after the fact. 03Motion with manners 120–320 milliseconds, one easing family. Animation explains where things went; it never asks for applause. 04Few parts, used well Nine components cover ninety percent of screens. Reach for composition before reaching for a new part. 02 Color Two layers: constant primitives for scale, semantic tokens for meaning. Products consume the semantic layer only — so re-theming is a variable swap, not a find-and-replace. Click any value to copy it. Primitive + Semantic Primitives — never used directly in product Semantic Tokens — the only layer product code touches Contrast, verified live Recomputes when you flip the theme 03 Typography Bricolage Grotesque carries display, Instrument Sans carries interface, and JetBrains Mono carries anything a machine reads. Ten steps cover every size on screen. 3 Families · 10 Steps Bricolage Grotesque Display · Headlines The quick brown fox jumps over the lazy dog — 0123456789 "Bricolage Grotesque", sans-serif · wght 200–800 · opsz 12–96 · wdth 75–100 Instrument Sans Text · UI The quick brown fox jumps over the lazy dog — 0123456789 "Instrument Sans", sans-serif · wght 400–700 JetBrains Mono Code · Data GET /v2/tokens → 200 OK · {} · 42ms "JetBrains Mono", monospace · wght 400–600 Type Scale Rhythm Variable font playground — click the specimen to edit it, drag the axes below. Weight (wght) 700 Width (wdth) 100 Optical (opsz) 96 04 Spacing & Motion A 4-point base grid, five radii, three elevations and one easing family. Distance is never guessed — it's picked from the scale. 4pt Base Grid Space — 9 steps Radius --radius-xs6px · tags --radius-sm8px · inputs --radius-md12px · buttons --radius-lg20px · cards --radius-fullpills Elevation --elev-1 · resting --elev-2 · raised --elev-3 · overlay Motion tokens One easing family — cubic-bezier(.2, 0, 0, 1) — plus a single spring for playful transforms. fast · 120ms base · 200ms slow · 320ms base · spring 05 Buttons Five variants, three sizes, four states. One primary action per view — everything else steps back. Every button below is live. 5 Variants · 3 Sizes Variants — live Click them, they're real h 40 · px 16 · r-md 12 · label 14/600 · icon 16 · gap 8 — primary: --color-accent / hover +8% dark / active +12% Sizes --ctrl-h tokens sm 32/13px · md 40/14px · lg 48/15px — density toggle in the top bar re-maps every height live. State matrix Forced states for review DefaultHoverFocusDisabled primary secondary ghost Focus uses a 2px accent outline at 2px offset — never removed, only styled. Loading state replaces the leading icon with a spinner. 06 Forms Fields share one anatomy — label, control, message — so states read at a glance. Validation is inline and specific, and it actually runs below. Anatomy + Controls Field states One anatomy Display name* Work email Visible to teammates only. Work email Enter a complete email address. Work email Looks good. API endpoint Managed by your administrator. Controls Select · Textarea · Check · Radio · Switch Team* Project briefoptional 0 / 280 Notifications All channels EmailDigest every morning at 9:00 SlackDeploys and incidents only Environment Staging Production Usage analyticsAnonymous product metrics collecting Beta featuresOpt into unreleased surfaces Project intake — live validation Blur validates · Submit checks everything Project name* Enter at least 2 characters. Owner's email* Enter a valid email address. Team* Choose a team. Briefoptional · max 280 0 / 280 I accept the design system contribution termsReviews happen within two working days. Please accept the terms to continue. novalidate on — validation is ours, not the browser's 07 Cards Four compositions, one skeleton: surface, radius-lg, elevation-1. Content changes; the frame doesn't. Hover any card to feel the single shared lift. 4 Compositions Card / Article — r-lg · elev-1 · media 16:8 Engineering Designing the Meridian grid How a 4-point spacing system and a 12-column layout keep every product surface consistent, from marketing site to console. AK Aiko KimuraJun 12 · 8 min read Card / Metric — sparkline · tabular numerals Weekly active teams 12.4% 2,847 vs. 2,532 last week · source: metrics.api Card / List — status dots · live pulse Deploys today api-core v2.14.0production · canary 10% 2m web-app v1.9.2staging · building now edge-worker v0.3.1failed · rolled back 41m Card / Call-to-action — accent-subtle surface Migrate your tokens tonight Run meridian sync to pull the latest token release into every product repo. Rollback is one command away. 08 Token Export Take the tokens with you. Paste into any stylesheet or pipeline — these are the same values currently styling this page. CSS · JSON /* ============================================ MERIDIAN — Design Tokens · v1.0.0 ============================================ */ :root { /* color · primitives (reference only) */ --accent-100:#F7E3D5; --accent-300:#E2A277; --accent-500:#C25E2B; --accent-600:#A8431F; --accent-700:#86351A; --neutral-100:#F5F1E8; --neutral-300:#D8CFBB; --neutral-600:#6C6454; --neutral-800:#332E24; --neutral-900:#201C15; /* color · semantic (product code uses these) */ --color-bg-canvas:#F7F4EE; --color-bg-surface:#FFFFFF; --color-bg-sunken:#EFEAE0; --color-bg-inverse:#201C15; --color-text-primary:#201C15;--color-text-secondary:#5D574B; --color-text-muted:#736B5D; --color-text-inverse:#F7F4EE; --color-border:#E3DCCC; --color-border-strong:#C9C0AE; --color-accent:#A8431F; --color-accent-hover:#8E3718; --color-accent-subtle:#F5E5D8;--color-accent-contrast:#FFFFFF; --color-success:#2E6B45; --color-warning:#8F6817; --color-danger:#B3321F; --color-info:#2A6072; /* typography */ --font-display:"Bricolage Grotesque",sans-serif; --font-text:"Instrument Sans",sans-serif; --font-mono:"JetBrains Mono",monospace; --text-display-xl:4.5rem; --leading-display:1.04; --text-h1:2.25rem; --leading-title:1.2; --text-body:1rem; --leading-body:1.6; --text-label:.8125rem; --tracking-caps:.08em; /* space — 4pt base */ --space-1:.25rem; --space-2:.5rem; --space-3:.75rem; --space-4:1rem; --space-5:1.5rem; --space-6:2rem; --space-7:3rem; --space-8:4rem; --space-9:6rem; /* radius · elevation · motion */ --radius-sm:8px; --radius-md:12px; --radius-lg:20px; --radius-full:999px; --elev-1:0 1px 2px rgb(32 28 21 / .06); --elev-2:0 2px 4px rgb(32 28 21 / .05), 0 10px 24px -10px rgb(32 28 21 / .14); --dur-fast:120ms; --dur-base:200ms; --dur-slow:320ms; --ease-out:cubic-bezier(.2, 0, 0, 1); } [data-theme="dark"] { --color-bg-canvas:#161310; --color-bg-surface:#1E1A15; --color-bg-sunken:#262119; --color-bg-inverse:#F1EDE3; --color-text-primary:#F1EDE3;--color-text-secondary:#B3AA9A; --color-text-muted:#8A8172; --color-text-inverse:#161310; --color-border:#332D24; --color-border-strong:#4A4336; --color-accent:#D57F4A; --color-accent-hover:#E08F5C; --color-accent-subtle:#3A2A1E;--color-accent-contrast:#201C15; --color-success:#7CC193; --color-warning:#E0A83E; --color-danger:#E36C55; --color-info:#6FA8BC; } { "meridian": { "version": "1.0.0", "color": { "bg": { "canvas": { "$type": "color", "$value": "#F7F4EE" }, "surface": { "$type": "color", "$value": "#FFFFFF" }, "sunken": { "$type": "color", "$value": "#EFEAE0" } }, "text": { "primary": { "$type": "color", "$value": "#201C15" }, "secondary": { "$type": "color", "$value": "#5D574B" }, "muted": { "$type": "color", "$value": "#736B5D" } }, "border": { "default": { "$type": "color", "$value": "#E3DCCC" }, "strong": { "$type": "color", "$value": "#C9C0AE" } }, "accent": { "base": { "$type": "color", "$value": "#A8431F" }, "hover": { "$type": "color", "$value": "#8E3718" }, "subtle": { "$type": "color", "$value": "#F5E5D8" }, "contrast": { "$type": "color", "$value": "#FFFFFF" } }, "status": { "success": { "$type": "color", "$value": "#2E6B45" }, "warning": { "$type": "color", "$value": "#8F6817" }, "danger": { "$type": "color", "$value": "#B3321F" }, "info": { "$type": "color", "$value": "#2A6072" } }, "dark": { "bg": { "$type": "color", "$value": "#161310" }, "text":{ "$type": "color", "$value": "#F1EDE3" }, "accent": { "$type": "color", "$value": "#D57F4A" } } }, "typography": { "family": { "display": { "$type": "fontFamily", "$value": ["Bricolage Grotesque", "sans-serif"] }, "text": { "$type": "fontFamily", "$value": ["Instrument Sans", "sans-serif"] }, "mono": { "$type": "fontFamily", "$value": ["JetBrains Mono", "monospace"] } }, "size": { "display-xl": { "$type": "dimension", "$value": "4.5rem" }, "h1": { "$type": "dimension", "$value": "2.25rem" }, "body": { "$type": "dimension", "$value": "1rem" }, "label": { "$type": "dimension", "$value": "0.8125rem" } } }, "space": { "1": { "$type": "dimension", "$value": "4px" }, "2": { "$type": "dimension", "$value": "8px" }, "3": { "$type": "dimension", "$value": "12px" }, "4": { "$type": "dimension", "$value": "16px" }, "5": { "$type": "dimension", "$value": "24px" }, "6": { "$type": "dimension", "$value": "32px" }, "7": { "$type": "dimension", "$value": "48px" }, "8": { "$type": "dimension", "$value": "64px" }, "9": { "$type": "dimension", "$value": "96px" } } } } Meridian Design System · v1.0.0 — a single-file living spec. BRICOLAGE GROTESQUE / INSTRUMENT SANS / JETBRAINS MONO ``` **What you're getting, and why I built it this way:** - **A real token architecture, not a swatch dump.** Two layers: constant primitives (10-step scales for accent, warm neutral, success, warning, danger) and semantic tokens (`--color-bg-canvas`, `--color-accent`…) that product code consumes. Flipping the theme is literally a variable remap — and the doc proves it. - **Self-verifying accessibility.** The contrast table computes WCAG ratios in JavaScript from the live computed values, so it re-audits the palette every time you toggle light/dark. Every pairing ships AA or better in both themes. - **Type with character.** Bricolage Grotesque for display, Instrument Sans for UI, JetBrains Mono for data — plus a variable-font playground (wght/wdth/opsz sliders, editable specimen) that outputs copy-ready CSS. - **Components that are actually wired.** Buttons fire toasts, the danger button uses a two-step "confirm" pattern instead of a browser dialog, the save button runs a real loading→success cycle, and the intake form validates on blur and submit with inline, specific errors. - **Two more token demos:** a density toggle (top bar) that re-maps every control height/padding live, and a motion lane showing the three duration tokens against the spring easing. - **Cards as asymmetric compositions** — article, metric with sparkline, deploy list, CTA — sharing one skeleton rather than a uniform grid. To adapt it to your product: swap the accent scale hexes, keep the semantic layer names, and everything downstream re-themes itself.

Color

Color

Designing the Meridian grid

Migrate your tokens tonight

Built once.Shipped everywhere.

Operating Principles

Tokens before values

Contrast is non-negotiable

Motion with manners

Few parts, used well

Color

Primitives — never used directly in product

Semantic Tokens — the only layer product code touches

Contrast, verified live

Typography

Type Scale

Spacing & Motion

Space — 9 steps

Radius

Elevation

Motion tokens

Buttons

Variants — live

Sizes

State matrix

Forms

Field states

Controls

Project intake — live validation

Cards

Designing the Meridian grid

Migrate your tokens tonight

Token Export

Built once.
Shipped everywhere.

Build a design system for my product. Include design tokens ...