# Codex Design System Notes These notes describe the inspected Codex desktop app, not Codium's implementation. The source snapshot was taken from the running macOS Codex app via the Chrome DevTools Protocol on `app://-/index.html?hostId=local`. Observed app version: - App title: `Codex` - User agent: `Codex/26.422.30944 Chrome/146.0.7680.179 Electron/41.2.0` - Theme class: `electron-dark` - Viewport sampled: `1344 x 877` ## Theming Pipeline (reverse-engineered) Codex generates ~149 CSS custom properties from **5 atomic user inputs** per theme, via a JS pre-pass that writes derived values onto ``'s inline `style`, plus a CSS layer that resolves the rest with `color-mix(in oklab, …)`. ### Inputs (per theme — `Light`, `Dark`) The user-editable theme object is persisted to `~/.codex/.codex-global-state.json` under `electron-persisted-atom-state.appearance{Light,Dark}ChromeTheme`: ```jsonc { "accent": "#0169cc", // link/highlight color "ink": "#0d0d0d", // foreground text/icon color "surface": "#ffffff", // primary surface color "contrast": 40, // 0–100 — single shaping knob "fonts": { "ui": "Geist, Inter", "code": "\"Geist Mono\", ui-monospace, ..." }, "opaqueWindows": true, // light=true, dark=false (vibrancy) "semanticColors": { "diffAdded": "#00a240", "diffRemoved": "#e02e2a", "skill": "#751ed9" } } ``` `appearanceTheme` (top-level) selects the resolved mode: `"light" | "dark" | "system"`. `system` queries `nativeTheme.shouldUseDarkColors`. ### Resolution flow 1. Resolve mode → pick the matching `appearance{Light,Dark}ChromeTheme` object. 2. Set `` class: - `electron-light` or `electron-dark` (resolved theme) - `+ electron-opaque` if `opaqueWindows: true` (Tailwind variant trigger) 3. Inline-style `` with the 5 base values verbatim: ```css --codex-base-accent: ; --codex-base-ink: ; --codex-base-surface: ; --codex-base-contrast: ; --vscode-font-family: ; --vscode-editor-font-family: ; ``` 4. JS pre-pass writes ~80 derived hex/rgba values onto the same inline `style`, so most tokens are concrete colors at runtime. 5. CSS rules add ~70 more tokens via `color-mix(in oklab, var(--color-text-foreground) X%, transparent)` etc., for the constant-alpha overlays. ### The shaping function Every contrast-driven token has the form: ``` value(contrast) = base + delta · t(contrast) ``` Where `t(0) = 0`, `t(100) = 1`, and `t(c) = (c/100)^p`. Fitting 9 different alpha tokens against the same shaping function yields tightly clustered exponents: - **Light theme:** `p ≈ 1.50` - **Dark theme:** `p ≈ 1.66` Dark uses a slightly steeper curve, presumably to compensate for vibrancy compositing reducing perceptual contrast on translucent surfaces. Each token defines its own `(base, delta)` pair; the curve `t(c)` is shared across all of them. ### Token derivation buckets | Bucket | Behavior | Example tokens | Formula | |---|---|---|---| | **A. Pass-through** | Literal copy of an input | `--color-text-foreground = ink`, `--color-background-surface = surface`, `--color-text-accent = accent` (light only) | `value = input` | | **B. Static-alpha ink overlays** | Constant alpha, contrast-independent | `--color-token-list-hover-background` (5%), `--color-token-bg-fog` (2.5%), `--color-token-badge-background` (4.7%), `--color-token-input-border` (7.4%) | `rgba(ink, k)` — k is per-token constant | | **C. Contrast-shaped ink overlays** | `rgba(ink, …)` ramped by contrast | `--color-border` (0.04 → 0.17), `--color-text-foreground-secondary` (0.60 → 0.93), `--color-background-button-primary-active` (0.04 → 0.44), `--color-icon-secondary`, `--color-text-foreground-tertiary` | `rgba(ink, base + delta · t(c))` | | **D. Surface ↔ ink mixes** | Slight tint of surface toward ink | `--color-background-surface-under` (sidebar/page bg) | `mix(surface, ink, base + delta · t(c))` | | **E. Surface ↔ accent mixes** | Pale accent backgrounds (selection/hover) | `--color-background-accent`, `--color-background-accent-hover`, `--color-background-accent-active` | `mix(surface, accent, base + delta · t(c))` | In **dark mode only**, `--color-text-accent` is itself a contrast-shaped mix toward `ink` (= white): ``` text-accent_dark(c) = mix(accent, ink, 0.19 + 0.46 · t(c)) ``` This auto-lightens the user-supplied accent (e.g. `#339cff`) toward white for legibility against `#181818`. Light mode leaves `accent` as a pass-through. ### Empirical token table (light theme, `ink=#0d0d0d`, `surface=#ffffff`, `accent=#0169cc`) | Token | c=0 | c=40 | c=100 | Formula | |---|---|---|---|---| | `--color-text-foreground` | `#0d0d0d` | `#0d0d0d` | `#0d0d0d` | `ink` | | `--color-background-surface` | `#ffffff` | `#ffffff` | `#ffffff` | `surface` | | `--color-background-surface-under` | `#ffffff` | `#f7f7f7` | `#e5e5e5` | `mix(surface, ink, 0.10·t(c))` | | `--color-text-foreground-secondary` | `rgba(13,13,13,0.598)` | `rgba(…,0.684)` | `rgba(…,0.933)` | `rgba(ink, 0.60 + 0.34·t(c))` | | `--color-text-foreground-tertiary` | `rgba(…,0.398)` | `rgba(…,0.484)` | `rgba(…,0.733)` | `secondary − 0.20` (constant offset) | | `--color-border` | `rgba(…,0.039)` | `rgba(…,0.074)` | `rgba(…,0.173)` | `rgba(ink, 0.04 + 0.13·t(c))` | | `--color-border-heavy` | `rgba(…,0.059)` | `rgba(…,0.111)` | `rgba(…,0.260)` | `rgba(ink, 0.06 + 0.20·t(c))` | | `--color-background-button-primary-active` | `rgba(…,0.037)` | `rgba(…,0.141)` | `rgba(…,0.440)` | `rgba(ink, 0.04 + 0.40·t(c))` | | `--color-background-accent` | `#e8f2fa` | `#e0ecf9` | `#c6def4` | `mix(surface, accent, 0.09 + 0.13·t(c))` | | `--color-token-list-hover-background` | `rgba(…,0.05)` | `rgba(…,0.05)` | `rgba(…,0.05)` | `rgba(ink, 0.05)` (constant) | | `--color-token-bg-fog` | `mix(oklab, ink 2.5%, transparent)` | same | same | constant alpha, CSS-only | ### Effects of changing each input | Input | Tokens affected | |---|---| | `accent` | Only the **accent family** (`text-accent`, `icon-accent`, `bg-accent`, `bg-accent-hover`, `bg-accent-active`) — ~6 tokens. Borders and ink overlays don't shift. | | `ink` | **Most tokens** — every `rgba(ink, α)` overlay plus surface↔ink mixes. Setting `ink: #ff0000` recolors borders, secondary text, fog, hover, etc., and tints `surface-under` toward red. | | `surface` | `background-surface` directly, plus all surface mixes (`surface-under`, `bg-accent` family, `dropdown`, `input-background`). | | `contrast` | Only the **contrast-shaped tokens** (~25). Static-alpha overlays don't move. | | `opaqueWindows` | Toggles vibrancy: light = opaque body, dark = `body { background: color(srgb 0.157 0.157 0.157 / 0.55) }` so macOS vibrancy shows through. Adds/removes `electron-opaque` class. | ### Design ideas 1. **Few inputs, many outputs.** A theme is a small JSON; designers pick 3 colors + 1 slider; "Copy theme" / "Import" exchange the JSON. 2. **Single shaping curve per theme.** Contrast isn't 25 knobs — it's one `t(c) = (c/100)^p` applied to every contrast-driven token. Per-token `(base, delta)` is the only thing that varies. 3. **Ink as an alpha source.** Dividers/secondary text/hover are `rgba(ink, α)`, not literal greys. Auto-flips with theme; works with custom ink colors; keeps perceptual contrast consistent. 4. **Accent stays on its own track.** Changing accent never recolors general tokens — only the explicit accent family. Custom themes can't go chaotic. 5. **Constant-alpha for ambient, contrast-shaped for interactive.** Fog/list-hover are quiet across the slider; borders/button states get punchier as the user dials contrast up — exactly what the slider name implies. 6. **Two-tier compute.** Heavy precomputed colors live in JS-injected inline style; light constant-alpha overlays stay in CSS via `color-mix(in oklab, …)` so they hot-recompute when ink changes. 7. **Theme-aware accent legibility.** Dark mode auto-mixes accent toward white as contrast increases, so users can pick any accent hue without worrying about contrast failures on `#181818`. 8. **Semantic colors are literal.** `diffAdded`/`diffRemoved`/`skill` bypass the derivation pipeline — they're direct inputs because diff red and OK green need to mean what they mean. ## Token Counts When the renderer settles, `getComputedStyle(:root)` reports ~149 reachable custom properties. They split as: | Layer | Count | Source | |---|---|---| | Inline-style chrome tokens | **65** | Computed in JS by `deriveTokens()` and written to `.style` | | `--color-token-*` design-system aliases | **96** | CSS-only, `var()` references to inline tokens | | Other (fonts, Tailwind base palette, VS Code editor tokens) | ~700 | Unrelated to chrome theme; bundled VS Code editor / framework defaults | The 65 + 96 ≈ 161 surface that chrome components actually consume. ## Built-in Themes Catalog Codex's `app.asar` bundles ~70 theme files. They split into two kinds based on what they export, and both kinds end up as selectable themes in the UI. ### Kind 1 — first-class chrome themes (12 files) These export a fully-formed `chromeTheme` object next to their VS Code-style `colors` object. They were authored explicitly for Codex's chrome — designer chose every input by hand: ```js // e.g. linear-dark.js export const chromeTheme = { accent: '#5e6ad2', contrast: 60, fonts: { ui: 'Inter', code: null }, ink: '#e3e4e6', opaqueWindows: true, semanticColors: { diffAdded: '#69c967', diffRemoved: '#ff7e78', skill: '#c2a1ff', }, surface: '#0f0f11', } ``` Bundled themes of this kind: **Linear Dark/Light, Vercel Dark/Light, Raycast Dark/Light, Notion Dark/Light, Sentry Dark, Lobster Dark, Matrix Dark, Proof Light** (12 entries). Plus the codex default in `appearance{Light,Dark}ChromeTheme` on the persistent global state file (counts as 2 more). The chrome theme object can be a partial — Codex merges it on top of the codex default for the same variant. Lobster, Matrix, Notion, Proof, and Sentry only override `fonts` and/or `opaqueWindows` and inherit everything chromatic from the codex default. ### Kind 2 — VS Code code themes (~55 files) The rest are pure VS Code colorTheme JSONs (Dracula, Tokyo Night, Catppuccin, One Dark Pro, Gruvbox, Monokai, Nord, Solarized, Material Theme, etc.). They define editor / activity-bar / terminal colors but **don't** carry a `chromeTheme` object: ```js // e.g. dracula.js { "editor.background": "#282A36", "editor.foreground": "#F8F8F2", "focusBorder": "#bd93f9", "activityBar.activeBorder": "#bd93f9", "terminal.ansiBlue": "#bd93f9", /* …50+ more editor.* / activityBar.* / terminal.* fields… */ } ``` When the user picks one of these from the code-theme picker, Codex **synthesizes a chrome theme on the fly** from the VS Code colors. The mapping is: | Chrome input | Source field (first non-null wins) | Notes | |---|---|---| | `surface` | `editor.background` | The dominant background color of the editor pane. | | `ink` | `editor.foreground` | The primary text color. | | `accent` | `focusBorder` → `activityBar.activeBorder` → `editorCursor.foreground` → `terminal.ansiBlue` → `button.background` | Pick the first that's non-transparent and ≠ surface. Themes whose `focusBorder` is `#XXXXXX00` (alpha 0) fall through to the next candidate. | | `contrast` | (codex default for variant) | 45 light / 60 dark. | | `opaqueWindows` | (codex default for variant) | `false` for both — code themes don't author this. | | `fonts` | (codex default) | Geist UI + Geist Mono code. | | `semanticColors.diffAdded` | (codex default for variant) | `#00a240` light / `#40c977` dark. | | `semanticColors.diffRemoved` | (codex default) | `#ba2623` / `#fa423e`. | | `semanticColors.skill` | (codex default) | `#924ff7` / `#ad7bf9`. | The synthesized chrome theme then runs through the same `deriveTokens()` pipeline as a first-class chrome theme — there's no separate code path. ### Catalog (Codium ships) | Kind | Source | Count | |---|---|---| | Codex defaults | `appearance{Light,Dark}ChromeTheme` global state | 2 | | First-class chrome themes | bundled `chromeTheme` exports | 12 | | Code-theme-derived | synthesized from `editor.*` / `focusBorder` | 55 | | **Total** | | **69** | ### Limitations of synthesis A code theme can't communicate the things that don't live in its color table: - **Contrast** — the `editor.*` JSON has no equivalent of the contrast knob, so all 55 derived themes start at the codex default contrast (45 / 60). The user can still adjust it in Settings → Appearance. - **`opaqueWindows`** — same: no signal for whether the window should be opaque vs translucent. Defaults to `false` (vibrancy on). - **Fonts** — code themes don't ship UI/code font preferences; we use the codex defaults. (Codex's first-class chrome themes like Linear sometimes do override fonts — `Inter` for Linear, `Satoshi` for Lobster.) - **Diff / skill colors** — these are intentionally meaningful (red-must-mean-error, green-must-mean-added) and code themes don't always agree on them, so we always use the codex default semantic colors. If you want a more faithful version of any synthesized theme, override the relevant inputs by hand — the chrome theme is just a JSON, persisted to `localStorage` by `applyPreset()`. ## JS Derivation Functions The runtime functions that compute the 65 inline tokens. Pseudocode pulled from the running app, normalized to the names used in `packages/codium/sources/theme/derive.ts`. ### Inputs ```ts type ChromeTheme = { accent: string // hex ink: string // hex (foreground) surface: string // hex (primary surface) contrast: number // 0..100 opaqueWindows: boolean fonts: { ui: string | null, code: string | null } semanticColors: { diffAdded: string, diffRemoved: string, skill: string } } type ThemeMode = 'light' | 'dark' ``` ### Color helpers ```ts type RGB = [number, number, number] const parseHex = (h: string): RGB => … // '#0d0d0d' → [13, 13, 13] const rgbToHex = (rgb: RGB): string => … // [13, 13, 13] → '#0d0d0d' const rgba = (rgb: RGB, a: number): string // → 'rgba(13, 13, 13, 0.123)' const rgb = (rgb: RGB): string // → 'rgb(13, 13, 13)' // Standard sRGB linear interpolation (the running app does NOT use oklab here // for the JS-side mixes; it only uses oklab for the CSS-side `color-mix`). const mix = (a: RGB, b: RGB, t: number): RGB => [ a[0] * (1 - t) + b[0] * t, a[1] * (1 - t) + b[1] * t, a[2] * (1 - t) + b[2] * t, ] const BLACK: RGB = [0, 0, 0] const WHITE: RGB = [255, 255, 255] ``` ### Shaping function The contrast slider is a **single** non-linear knob applied to every contrast-driven token. Each mode has its own exponent. ```ts const shape = (contrast: number, mode: ThemeMode): number => { const c = clamp01(contrast / 100) const p = mode === 'dark' ? 1.66 : 1.50 return Math.pow(c, p) } const apply = (curve: { base: number, delta: number }, t: number) => curve.base + curve.delta * t ``` ### Per-token coefficient table Empirically fit from snapshots of the running Codex app. ```ts const COEFFS: Record = { light: { p: 1.5, fgSecondary: { base: 0.598, delta: 0.335 }, fgTertiary: { base: 0.398, delta: 0.335 }, border: { base: 0.04, delta: 0.133 }, borderHeavy: { base: 0.06, delta: 0.20 }, borderLight: { base: 0.03, delta: 0.067 }, iconPrimary: 'passthrough', // light: ink as-is btnPrimaryActive: { base: 0.04, delta: 0.40 }, btnPrimaryHover: { base: 0.02, delta: 0.20 }, btnPrimaryInactive: { base: 0.151, delta: 0.306 }, btnSecondary: { base: 0.037, delta: 0.041 }, btnSecondaryActive: { base: 0.027, delta: 0.041 }, btnSecondaryHover: { base: 0.035, delta: 0.061 }, btnSecondaryInactive: { base: 0.007, delta: 0.041 }, btnTertiary: { base: 0, delta: 0 }, // always transparent btnTertiaryActive: { base: 0.140, delta: 0.184 }, btnTertiaryHover: { base: 0.073, delta: 0.082 }, surfUnder: { base: 0.0, delta: 0.10 }, // mix(surface, ink) bgAccent: { base: 0.09, delta: 0.13 }, // mix(surface, accent) bgAccentHover: { base: 0.10, delta: 0.15 }, bgAccentActive: { base: 0.11, delta: 0.16 }, accentForegroundMix: { base: 0, delta: 0 }, // light: passthrough accentPurple: '#751ed9', decorationAdded: '#00a240', decorationDeleted: '#e02e2a', editorOverlayAlpha: 0.15, }, dark: { p: 1.66, fgSecondary: { base: 0.58, delta: 0.303 }, fgTertiary: { base: 0.329, delta: 0.394 }, border: { base: 0.032, delta: 0.121 }, borderHeavy: { base: 0.078, delta: 0.182 }, borderLight: { base: 0.016, delta: 0.061 }, iconPrimary: { base: 0.79, delta: 0.27 }, btnPrimaryActive: { base: 0.035, delta: 0.152 }, btnPrimaryHover: { base: 0.019, delta: 0.091 }, btnPrimaryInactive: { base: 0.017, delta: 0.036 }, btnSecondary: { base: 0.037, delta: 0.036 }, btnSecondaryActive: { base: 0.078, delta: 0.099 }, btnSecondaryHover: { base: 0.051, delta: 0.063 }, btnSecondaryInactive: { base: 0.015, delta: 0.054 }, btnTertiary: { base: 0.017, delta: 0.027 }, btnTertiaryActive: { base: 0.058, delta: 0.099 }, btnTertiaryHover: { base: 0.041, delta: 0.063 }, surfUnder: { base: 0.05, delta: 0.16 }, // mix(surface, BLACK) bgAccent: { base: 0.17, delta: 0.19 }, // mix(BLACK, accent) bgAccentHover: { base: 0.18, delta: 0.21 }, bgAccentActive: { base: 0.20, delta: 0.23 }, accentForegroundMix: { base: 0.19, delta: 0.46 }, accentPurple: '#ad7bf9', decorationAdded: '#40c977', decorationDeleted: '#fa423e', editorOverlayAlpha: 0.23, }, } // Dark-mode-only "above surface" mixes (no headroom in light because // surface is already at maximum brightness). const DARK_SURFACE_MIX = { controlOpaque: { base: 0.049, delta: 0.099 }, // mix(surface, ink, …) editorOpaque: { base: 0.058, delta: 0.027 }, // mix(surface, ink, …) elevatedPrimary: { base: 0.053, delta: 0.180 }, // mix(surface, ink, …) buttonPrimaryFill: { base: 0.46, delta: 0 }, // mix(surface, BLACK, …) textBtnSecondary: { base: 0.20, delta: 0.09 }, // mix(surface, ink, …) } ``` ### Main derivation ```ts function deriveTokens(theme: ChromeTheme, mode: ThemeMode): Record { const ink = parseHex(theme.ink) const surface = parseHex(theme.surface) const accent = parseHex(theme.accent) const t = shape(theme.contrast, mode) const C = COEFFS[mode] const inkA = (alpha: number) => rgba(ink, alpha) const inkOverlay = (curve: Curve) => inkA(apply(curve, t)) // — accent foreground (legibility) const accentFg = mode === 'dark' ? rgbToHex(mix(accent, WHITE, apply(C.accentForegroundMix, t))) : theme.accent // — surface "below" (page / sidebar bg) — quieter than surface in both modes const surfaceUnder = rgbToHex(mix( surface, mode === 'dark' ? BLACK : ink, apply(C.surfUnder, t), )) // — surface "above" (panel / elevated / control / editor) const above = mode === 'dark' ? { control: mix(surface, ink, apply(DARK_SURFACE_MIX.controlOpaque, t)), editor: mix(surface, ink, apply(DARK_SURFACE_MIX.editorOpaque, t)), elevated: mix(surface, ink, apply(DARK_SURFACE_MIX.elevatedPrimary, t)), } : { control: surface, editor: surface, elevated: surface } // — bg-accent family (selection / hover accent) const bgAccentBase = mode === 'dark' ? BLACK : surface const bgAccentRgb = mix(bgAccentBase, accent, apply(C.bgAccent, t)) const bgAccentHoverRgb = mix(bgAccentBase, accent, apply(C.bgAccentHover, t)) const bgAccentActiveRgb = mix(bgAccentBase, accent, apply(C.bgAccentActive, t)) // — primary button fill const buttonPrimaryFill = mode === 'dark' ? mix(surface, BLACK, apply(DARK_SURFACE_MIX.buttonPrimaryFill, t)) : ink return { // base inputs (echoed) '--codex-base-accent': theme.accent, '--codex-base-ink': theme.ink, '--codex-base-surface': theme.surface, '--codex-base-contrast': String(theme.contrast), // fonts '--vscode-font-family': appendFontFallback(theme.fonts.ui ?? 'Geist, Inter', 'sans'), '--vscode-editor-font-family': appendFontFallback(theme.fonts.code ?? '"Geist Mono", ui-monospace, "SFMono-Regular"', 'mono'), // typography (fixed; not theme-dependent) '--text-xs': '11px', '--text-sm': '12px', '--text-base': '13px', '--text-lg': '16px', '--text-heading-sm': '18px', '--text-heading-md': '20px', '--text-heading-lg': '24px', '--text-xl': '28px', '--text-2xl': '36px', '--text-3xl': '48px', '--text-4xl': '72px', '--vscode-font-size': '13px', '--vscode-editor-font-size': '12px', // pass-throughs / accent '--color-text-foreground': theme.ink, '--color-icon-primary': C.iconPrimary === 'passthrough' ? theme.ink : inkA(apply(C.iconPrimary, t)), '--color-text-accent': accentFg, '--color-icon-accent': accentFg, '--color-background-surface': theme.surface, '--color-accent-blue': theme.accent, '--color-accent-purple': C.accentPurple, // static-alpha ink overlays '--color-hover': inkA(0.05), '--color-token-list-hover-background': inkA(0.05), '--color-token-toolbar-hover-background': inkA(0.05), '--color-token-badge-background': inkA(0.047), '--color-token-input-border': inkA(0.074), '--color-token-bg-fog': inkA(0.025), // contrast-shaped ink overlays '--color-text-foreground-secondary': inkOverlay(C.fgSecondary), '--color-text-foreground-tertiary': inkOverlay(C.fgTertiary), '--color-icon-secondary': inkOverlay(C.fgSecondary), '--color-icon-tertiary': inkOverlay(C.fgTertiary), '--color-border': inkOverlay(C.border), '--color-border-heavy': inkOverlay(C.borderHeavy), '--color-border-light': inkOverlay(C.borderLight), '--color-active': inkA(0.04 + 0.06 * t), '--color-button-bg': inkA(0.04 + 0.06 * t), '--color-button-hover': inkA(0.04 + 0.04 * t), // simple-scrim: BLACK in light, INK in dark '--color-simple-scrim': mode === 'light' ? rgba(BLACK, 0.06 + 0.13 * t) : inkA(0.06 + 0.13 * t), // button background family '--color-background-button-primary': mode === 'dark' ? rgb(buttonPrimaryFill) : rgbToHex(buttonPrimaryFill), '--color-background-button-primary-active': inkOverlay(C.btnPrimaryActive), '--color-background-button-primary-hover': inkOverlay(C.btnPrimaryHover), '--color-background-button-primary-inactive': inkOverlay(C.btnPrimaryInactive), '--color-background-button-secondary': inkOverlay(C.btnSecondary), '--color-background-button-secondary-active': inkOverlay(C.btnSecondaryActive), '--color-background-button-secondary-hover': inkOverlay(C.btnSecondaryHover), '--color-background-button-secondary-inactive': inkOverlay(C.btnSecondaryInactive), '--color-background-button-tertiary': inkOverlay(C.btnTertiary), '--color-background-button-tertiary-active': inkOverlay(C.btnTertiaryActive), '--color-background-button-tertiary-hover': inkOverlay(C.btnTertiaryHover), // text on buttons '--color-text-button-primary': mode === 'dark' ? rgb(buttonPrimaryFill) : theme.surface, '--color-text-button-secondary': mode === 'dark' ? rgbToHex(mix(surface, ink, apply(DARK_SURFACE_MIX.textBtnSecondary, t))) : theme.ink, '--color-text-button-tertiary': inkOverlay(C.fgTertiary), // surface family '--color-background-surface-under': surfaceUnder, '--color-background-panel': mode === 'dark' ? rgbToHex(mix(surface, ink, 0.07)) : theme.surface, '--color-background-control': rgba(above.control, 0.96), '--color-background-control-opaque': rgb(above.control), '--color-background-editor-opaque': rgb(above.editor), '--color-background-elevated': rgba(above.elevated, 0.96), '--color-background-elevated-primary': rgba(above.elevated, 0.96), '--color-background-elevated-primary-opaque': rgb(above.elevated), '--color-background-elevated-secondary': mode === 'dark' ? inkOverlay(C.btnPrimaryInactive) : rgba(surface, 0.96), '--color-background-elevated-secondary-opaque': rgbToHex(above.editor), // accent backgrounds '--color-background-accent': rgbToHex(bgAccentRgb), '--color-background-accent-hover': rgbToHex(bgAccentHoverRgb), '--color-background-accent-active': rgbToHex(bgAccentActiveRgb), // focus ring '--color-border-focus': mode === 'dark' ? rgba(parseHex(accentFg), 0.76) : theme.accent, // fixed brand: diff / editor overlays '--color-decoration-added': C.decorationAdded, '--color-decoration-deleted': C.decorationDeleted, '--color-editor-added': rgba(parseHex(C.decorationAdded), C.editorOverlayAlpha), '--color-editor-deleted': rgba(parseHex(C.decorationDeleted), C.editorOverlayAlpha), // legacy semantic-color shortcuts '--color-accent-green': theme.semanticColors.diffAdded, '--color-accent-red': theme.semanticColors.diffRemoved, } } ``` ### Apply to the document ```ts function applyTheme(theme: ChromeTheme, mode: ThemeMode) { const root = document.documentElement for (const [k, v] of Object.entries(deriveTokens(theme, mode))) { root.style.setProperty(k, v) } root.classList.toggle('electron-light', mode === 'light') root.classList.toggle('electron-dark', mode === 'dark') root.classList.toggle('electron-opaque', !!theme.opaqueWindows) root.style.colorScheme = mode } ``` ## CSS-Side Aliases Codex defines ~96 `--color-token-*` design-system aliases in CSS that reference the inline-injected tokens. Components consume these via Tailwind utilities (e.g. `bg-token-input-background`, `text-token-foreground`). They live in CSS so they hot-recompute when an inline token changes — no JS re-derive needed. Most are `var()` references; a few are `color-mix()` derivations; status/error/charts colors are fixed brand colors per mode. ```css :root { /* text aliases */ --color-token-foreground: var(--color-text-foreground); --color-token-text-primary: var(--color-text-foreground); --color-token-text-secondary: var(--color-text-foreground-secondary); --color-token-text-tertiary: var(--color-text-foreground-tertiary); --color-token-description-foreground: var(--color-text-foreground-tertiary); --color-token-disabled-foreground: var(--color-text-foreground-tertiary); /* icon */ --color-token-icon-foreground: var(--color-icon-primary); /* surface / background */ --color-token-main-surface-primary: var(--color-background-surface); --color-token-bg-primary: var(--color-background-surface-under); --color-token-bg-secondary: color-mix(in srgb, var(--color-background-surface-under) 92%, transparent); --color-token-bg-tertiary: color-mix(in srgb, var(--color-background-surface-under) 85%, transparent); --color-token-side-bar-background: var(--color-background-surface-under); --color-token-input-background: var(--color-background-control); --color-token-dropdown-background: var(--color-background-elevated-primary-opaque); --color-token-menu-background: var(--color-background-elevated-primary); --color-token-checkbox-background: var(--color-background-elevated-primary); --color-token-bg-fog: color-mix(in oklab, var(--color-text-foreground) 2.5%, transparent); /* input / checkbox / menu */ --color-token-input-foreground: var(--color-text-foreground); --color-token-input-placeholder-foreground: var(--color-text-foreground-tertiary); --color-token-input-border: var(--color-border); --color-token-checkbox-foreground: var(--color-text-foreground); --color-token-checkbox-border: var(--color-border); --color-token-menu-border: var(--color-border); --color-token-menubar-selection-foreground: var(--color-text-foreground); --color-token-menubar-selection-background: var(--color-token-bg-fog); --color-token-radio-active-foreground: var(--color-text-foreground); /* link */ --color-token-link: var(--color-text-accent); --color-token-text-link-foreground: var(--color-text-accent); --color-token-text-link-active-foreground: var(--color-text-accent); /* border */ --color-token-border: var(--color-border); --color-token-border-default: var(--color-border); --color-token-border-heavy: var(--color-border-heavy); --color-token-border-light: var(--color-border-light); --color-token-focus-border: var(--color-border-focus); --color-token-list-focus-outline: var(--color-border-focus); /* button */ --color-token-button-background: var(--color-background-button-primary); --color-token-button-foreground: var(--color-background-button-primary); --color-token-button-border: var(--color-border); --color-token-button-secondary-hover-background: var(--color-background-button-secondary-hover); /* list / hover */ --color-token-list-hover-background: var(--color-background-button-tertiary-hover); --color-token-toolbar-hover-background: var(--color-background-button-tertiary-hover); --color-token-list-active-selection-background: var(--color-background-button-secondary); --color-token-list-active-selection-foreground: var(--color-text-foreground); --color-token-list-active-selection-icon-foreground: var(--color-icon-primary); /* badge */ --color-token-badge-background: var(--color-background-button-secondary); --color-token-badge-foreground: var(--color-text-foreground-secondary); /* code block */ --color-token-text-code-block-background: var(--color-border); /* scrollbar */ --color-token-scrollbar-slider-background: var(--color-border); --color-token-scrollbar-slider-hover-background: var(--color-border-heavy); --color-token-scrollbar-slider-active-background: var(--color-border-heavy); /* editor */ --color-token-editor-foreground: var(--color-text-foreground); --color-token-editor-background: var(--color-background-editor-opaque); --color-token-editor-error-foreground: #ff6764; --color-token-editor-warning-foreground: #ff8549; /* terminal */ --color-token-terminal-foreground: var(--color-text-foreground); --color-token-terminal-background: var(--color-background-surface); --color-token-terminal-border: var(--color-border); --color-token-terminal-ansi-black: var(--color-text-foreground-tertiary); --color-token-terminal-ansi-bright-black: var(--color-text-foreground-secondary); --color-token-terminal-ansi-blue: var(--color-accent-blue); --color-token-terminal-ansi-bright-blue: var(--color-accent-blue); --color-token-terminal-ansi-cyan: var(--color-accent-blue); --color-token-terminal-ansi-bright-cyan: var(--color-accent-blue); --color-token-terminal-ansi-green: var(--color-decoration-added); --color-token-terminal-ansi-bright-green: var(--color-decoration-added); --color-token-terminal-ansi-magenta: var(--color-accent-purple); --color-token-terminal-ansi-bright-magenta: var(--color-accent-purple); --color-token-terminal-ansi-red: #ff6764; --color-token-terminal-ansi-bright-red: #ff6764; --color-token-terminal-ansi-white: var(--color-text-foreground); --color-token-terminal-ansi-bright-white: var(--color-text-foreground); --color-token-terminal-ansi-yellow: #ffd240; --color-token-terminal-ansi-bright-yellow: #ffd240; /* charts */ --color-token-charts-blue: var(--color-accent-blue); --color-token-charts-green: var(--color-decoration-added); --color-token-charts-orange: #fb6a22; --color-token-charts-purple: var(--color-accent-purple); --color-token-charts-red: #ff6764; --color-token-charts-yellow: #ffd240; /* git decoration */ --color-token-git-decoration-added-resource-foreground: var(--color-decoration-added); --color-token-git-decoration-deleted-resource-foreground: var(--color-decoration-deleted); /* diff surface (mix toward foreground for contrast) */ --color-token-diff-surface: color-mix(in srgb, var(--color-background-surface) 94%, var(--color-text-foreground)); /* error / warning / status */ --color-token-error-foreground: #ff6764; --color-icon-warning: #ff8549; --color-background-status-error: #4d100e; --color-background-status-warning: #4a2206; --color-background-status-success: color-mix(in oklab, #04b84c 16%, transparent); } /* Light-mode tweaks for status/error tokens whose dark default doesn't read on a light surface */ html.electron-light { --color-token-editor-error-foreground: #b6161c; --color-token-editor-warning-foreground: #b55a16; --color-token-error-foreground: #b6161c; --color-token-terminal-ansi-red: #b6161c; --color-token-terminal-ansi-bright-red: #b6161c; --color-token-charts-red: #b6161c; --color-token-charts-orange: #b04300; --color-token-charts-yellow: #ad7e00; --color-icon-warning: #b55a16; --color-background-status-error: color-mix(in oklab, #b6161c 12%, transparent); --color-background-status-warning: color-mix(in oklab, #b55a16 12%, transparent); --color-background-status-success: color-mix(in oklab, #04b84c 12%, transparent); } ``` ## Visual Direction Codex is a dense desktop tool UI. It uses a transparent macOS sidebar, a dark rounded main surface, compact 28-30px controls, low-contrast token borders, and almost no decorative gradients. The design language is practical and quiet: - Surfaces are flat or slightly elevated. - Borders are usually translucent white at very low opacity. - Hover states use subtle translucent fills. - Gradients are functional, mostly for resize affordances and fade masks. - Text is small: 12px for sidebar/control labels, 13px for body and menus. ## Token Vocabulary Codex uses Tailwind-like utility classes backed by semantic tokens. The important observed class families are: | Family | Examples | Meaning | | --- | --- | --- | | Text | `text-token-foreground`, `text-token-description-foreground`, `text-token-muted-foreground`, `text-token-text-link-foreground` | Primary, secondary, muted, and link text | | Background | `bg-token-bg-fog`, `bg-token-input-background/90`, `bg-token-side-bar-background`, `bg-token-dropdown-background` | Quiet control, composer, sidebar, dropdown surfaces | | Border | `border-token-border`, `border-token-border/70`, `bg-token-border-default` | Default borders and dividers | | Hover | `hover:bg-token-list-hover-background`, `enabled:hover:bg-token-list-hover-background` | Row/control hover fill | | Radius | `rounded-lg`, `rounded-md`, `rounded-full`, `rounded-3xl`, `rounded-s-2xl` | Rows, icon buttons, pills, composer, main surface | | Sizing | `h-toolbar`, `h-token-button-composer`, `h-token-button-composer-sm`, `size-token-button-composer` | Header and compact button heights | | Spacing | `px-row-x`, `py-row-y`, `px-toolbar`, `px-panel` | System row/header/panel spacing | Computed dark colors from the inspected UI: | Use | Value | | --- | --- | | Body translucent window background | `color(srgb 0.156863 0.156863 0.156863 / 0.55)` | | Main surface | `rgb(24, 24, 24)` | | Primary foreground | `rgb(255, 255, 255)` | | Tertiary/muted foreground | `rgba(255, 255, 255, 0.498)` | | Link/accent text | `rgb(131, 195, 255)` | | Button fog background | `rgba(255, 255, 255, 0.03)` | | Standard border on split buttons | `rgba(255, 255, 255, 0.082)` | | Main surface outline ring | `rgba(255, 255, 255, 0.157)` | | Main surface shadow | `rgba(0, 0, 0, 0.08) 0px 2px 4px -1px` | ## Typography Observed text sizes: | Context | Size | Line height | Weight | | --- | --- | --- | --- | | Body/default browser base | `16px` | `24px` | `400` | | App body text / editor | `13px` | `19.5px` | `400` | | Sidebar rows | `12px` | `17.1429px` | `400` | | Composer footer labels | `12px` | `18px` | `400` | | Header split buttons | `13px` | `18px` | `400` | | Home headline | class `heading-xl` | not measured in this pass | `400` via `font-normal` | Use `truncate`, `min-w-0`, and `whitespace-nowrap` heavily. Codex prefers one-line labels with ellipsis over wrapping in navigation and controls. ## App Shell ### Window Background The body is translucent: ```css background-color: color(srgb 0.156863 0.156863 0.156863 / 0.55); ``` The sidebar sits on this transparent window background rather than a solid panel. ### Sidebar Measured sidebar: - Width: `318.93px` (`319px` target). - Height: full viewport. - Top padding: `46px`, matching toolbar height. - Background: transparent. - Border: no visible solid sidebar border in the sampled aside itself. - Nav content begins at `y = 46px`. Sidebar nav rows: - Row width: `302.93px`. - Row height: `29.5px`. - Row padding: `5px 8px`. - Row gap: `8px`. - Row radius: `12.5px`. - Text size: `12px`. - Line height: `17.1429px`. - Hover class: `hover:bg-token-list-hover-background`. - Focus: `focus-visible:outline-token-border`, `outline-2`, `outline-offset-2`. Section headers such as `Projects` are quieter: - Height: `23.5px`. - Padding: `2px 4px 2px 0`. - Radius: `10px`. - Text size: `13px`. - Color: `rgba(255, 255, 255, 0.498)`. ### Main Surface The main work surface is the strongest framed shape: - Left offset: starts after `319px` sidebar. - Background: `rgb(24, 24, 24)`. - Radius: `12.5px 0 0 12.5px` (`rounded-s-2xl`). - Shadow stack: ```css box-shadow: rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(255, 255, 255, 0.157) 0px 0px 0px 0.5px, rgba(0, 0, 0, 0.08) 0px 2px 4px -1px; ``` The important detail is the `0.5px` translucent white ring. This is the primary border for the main surface. ## Borders Borders are tokenized and low contrast. They are used more as surface separators than visible outlines. ### Default Border Split buttons and framed header controls use: ```css border-color: rgba(255, 255, 255, 0.082); ``` Observed on header split buttons: - `border-token-border` - `border` - `border-r-0` or `border-l-0` for attached split-button halves. ### Transparent Border Reservation Many buttons use `border-transparent` while still carrying the `border` class. This reserves layout space so hover/open states do not shift the control. Observed examples: - Sidebar/top icon buttons. - Composer icon buttons. - Tertiary toolbar buttons. ### Divider Border Codex uses `border-token-border/70` and `divide-token-border/70` for quieter separators in menus/lists. The intent is visible separation only at close range. ### Focus Border Focus rings are outlines, not heavier borders: - `focus-visible:outline` - `focus-visible:outline-2` - `focus-visible:outline-offset-2` - `focus-visible:outline-token-border` Composer send focus uses `focus-visible:outline-token-button-background`. ## Gradients And Fades Codex uses very few gradients. They are utility/affordance gradients, not decorative backgrounds. ### Sidebar Resize Handle The clearest actual gradient is the sidebar resize handle: ```text sidebar-resize-handle-line bg-gradient-to-b from-transparent via-token-foreground/25 to-transparent ``` Measured handle: - Width: `1px`. - Height: `923px` in the sampled viewport. - Horizontal margin: `0 5.5px`. - Initial opacity: `0`. - Visible on group hover/active via `group-hover:opacity-100` and `group-active:opacity-100`. This gradient is a vertical line that fades at both ends. ### Text Fade Masks Long sidebar/folder rows use mask gradients when hover/focus actions appear: ```text group-focus-within:[mask-image:linear-gradient(to_right,transparent_0,transparent_21px,black_26px)] group-hover:[mask-image:linear-gradient(to_right,transparent_0,transparent_21px,black_26px)] ``` This is not a visible background gradient. It is a text/content mask that prevents overlap with row actions. ### Scroll Fade Mask The sidebar contains `vertical-scroll-fade-mask`, indicating a vertical fade at scroll boundaries. Treat this as a functional overflow affordance. ### Not Used As Decoration No large hero gradients, orb gradients, or decorative color washes were observed. The main app depends on surface color, blur, borders, and shadows instead. ## Toolbar And Header Controls Header controls are compact, often split-button pairs. Observed split button values: - Height: `28px`. - Text size: `13px`. - Line height: `18px`. - Background: `rgba(255, 255, 255, 0.03)` (`bg-token-bg-fog`). - Border: `rgba(255, 255, 255, 0.082)`. - Left half radius: `12.5px 0 0 12.5px`. - Right half radius: `0 12.5px 12.5px 0`. - Left half padding: `0 4px 0 8px`. - Right half padding: `0 6px 0 2px`. - Icon-only tertiary buttons: `36px x 28px`, padding `0 8px`, radius `12.5px`, transparent border/background. Attached split buttons remove the shared border: - Left half: `border-r-0`. - Right half: `border-l-0`. ## Composer The Codex composer is a centered, elevated input with a pill-like rounded shape. Observed classes: ```text rounded-3xl bg-token-input-background/90 ring ring-black/10 backdrop-blur-lg electron:shadow-[0_4px_16px_0_rgba(0,0,0,0.05)] electron:dark:bg-token-dropdown-background ``` Measured composer/editor area: - Composer content width: `728px`. - Editor visual width: `704px`. - Editor height in empty state: `40px`. - Editor max height: `25dvh`. - ProseMirror min height: `2rem`. - Text size: `13px`. - Line height: `19.5px`. Composer footer: - Width: `728px`. - Height: `28px`. - Display: grid. - Columns: `minmax(0, auto) auto minmax(0, 1fr)`. - Gap: `5px`. - Padding: `0 8px`. - Margin bottom: `8px`. Footer controls: - Main button height: `28px`. - Small button height: `28px` in measured state. - Label font: `12px`. - Label line height: `18px`. - Pill radius: `9999px`. - Text color for inactive controls: `rgba(255, 255, 255, 0.498)`. - Link/accent label color: `rgb(131, 195, 255)`. - Icon-only composer buttons: `28px x 28px`. - Send button: `28px x 28px`, `9999px` radius, white background, `0.5` opacity when disabled. ## Buttons General button pattern: - Keep a `border` even when transparent. - Use `cursor-interaction`. - Use `user-select-none`. - Use `whitespace-nowrap`. - Disabled state: `disabled:cursor-not-allowed` and either `disabled:opacity-40` or `disabled:opacity-50`. - Hover/open state: `enabled:hover:bg-token-list-hover-background` and `data-[state=open]:bg-token-list-hover-background`. Control sizes: | Control | Size | | --- | --- | | Sidebar row | `303px x 30px` sampled | | Header split button | `28px` high | | Header icon-only tertiary | `36px x 28px` | | Sidebar section icon button | `24px x 24px` | | Composer icon button | `28px x 28px` | | Composer send button | `28px x 28px` | ## Radius Scale Observed radii: | Radius | Use | | --- | --- | | `10px` | Section toggle, compact icon button | | `12.5px` | Sidebar rows, header split buttons, main surface side radius | | `9999px` | Composer footer pills and circular send button | | `rounded-3xl` | Composer shell | | `rounded-b-2xl` | Lower rounded panel in prompt/options area | Codex often uses `rounded-lg` utility classes, but computed radius in the sampled environment is `12.5px`. ## Spacing Scale Observed spacing: | Context | Value | | --- | --- | | Sidebar row padding | `5px 8px` | | Sidebar row gap | `8px` | | Section toggle padding | `2px 4px 2px 0` | | Header split left padding | `0 4px 0 8px` | | Header split right padding | `0 6px 0 2px` | | Header icon padding | `0 8px` | | Composer footer padding | `0 8px` | | Composer footer gap | `5px` | | Composer footer bottom margin | `8px` | | Composer small pill padding | `0 6px` | | Composer standard pill padding | `0 8px` | ## Shadows And Elevation Codex uses minimal elevation: - Main surface: `0.5px` white ring plus subtle shadow. - Composer: `0 4px 16px rgba(0,0,0,0.05)` in Electron. - Dropdown/composer background uses blur and opaque token surfaces rather than large shadows. The main visual separation comes from border rings and surface contrast, not heavy drop shadows. ## Plugins Catalog The Plugins screen keeps the same shell but uses content-centered catalog sections. Observed structure: - Main content still begins at `x = 319px` and uses the same `main-surface`. - Header height remains `46px`. - Content column is centered with `max-width` around `736px`. - Catalog sections use transparent backgrounds and `gap-4`. - Section examples: - Featured/plugin rows: `x = 463`, `width = 736`. - Vertical section gaps are large enough that categories read as separate bands without card wrappers. Header tabs/actions on the Plugins page: - Header text includes `Plugins`, `Skills`, `Manage`, `Create`. - These are compact header controls rather than large tabs. - They inherit the same 28px control language as toolbar buttons. Plugin detail rows/cards: - Plugin settings pages use bordered list cards rather than heavy panels. - Example Computer Use plugin row: - Rect: `672px x 62px`. - Radius: `12.5px`. - Border: `1px rgba(255, 255, 255, 0.082)`. - Class pattern: `border-token-border/40 flex flex-col gap-2.5 rounded-2xl border p-2.5 transition`. - Action button such as `Try in Chat`: - Size: `28px x 28px`. - Radius: `10px`. - Transparent background and transparent reserved border. ## Automations The Automations screen introduces rounded prompt/template cards. Page layout: - Header action: `New automation`, white filled button. - Content header column: `x = 447`, `width = 768`, with `px-panel`. - Template section width: `728px`. - Template sections use `flex flex-col gap-4`. Automation template cards: - Card width: `356px`. - Card height: usually `97px`; shorter cards can be `78px`. - Two-column grid inside the `728px` content column. - Background: `oklab(0.297161 0.0000135154 0.00000594556 / 0.672549)`. - Border: `1px oklab(0.999994 0.0000455678 0.0000200868 / 0.0411765)`. - Radius: `30px` (`rounded-4xl`). - Padding class: `px-3 py-3`. - Text size: `13px`, line-height `19.5px`. - Hover classes strengthen the card: `hover:border-token-border` and `hover:bg-token-input-background`. This is the largest radius observed in normal content cards. It is used for selectable prompt templates, not ordinary panels. ## Account Popover Clicking the sidebar `Settings` row first opens an account popover near the lower-left sidebar. Measured popover: - Rect: `x = 8`, `y = 663`, `width = 282`, `height = 176`. - It contains account identity, account type, settings, rate limits, and log out. - The popover itself is visually transparent in computed background, relying on internal menu structure and separators. - Separators: - Width: `256px`. - Height: `1px`. - Background: `rgba(255, 255, 255, 0.082)`. - Class: `bg-token-menu-border`. This popover confirms menu separators use the same low-contrast border color as split-button borders. ## Settings Shell The actual Settings surface is a separate app state with a fixed left settings nav and a right content panel. Settings nav: - Nav width: `300px`. - Nav starts below toolbar at `y = 46px`. - Nav padding class: `px-row-x`. - Row width: `284px`. - Row height: `30px`. - Row padding uses the same `px-row-x py-row-y` token pair as main sidebar rows. - Row radius: `12.5px`. - Row text: `12px`, line-height `17.1429px`. - Active background: `rgba(255, 255, 255, 0.08)`. - Items observed: - General - Appearance - Configuration - Personalization - MCP servers - Git - Environments - Worktrees - Browser use - Computer use - Archived chats - Usage Settings content: - Content starts at `x = 300px`. - Top header strip: `height = 46px`. - Scroll panel: `x = 300`, `y = 46`, `width = 1044`, `height = 831`. - Content class: `flex-1 overflow-y-auto p-panel`. - Inner content column: - Usually `x = 486`. - Width: `672px`. - Header block height: `67px`. - Section group gap: `var(--padding-panel)`. Settings headings are plain text blocks, not cards. Most settings sections are transparent rows and sections; controls provide the visual weight. ## Settings: General General contains work-mode cards, switches, dropdown buttons, and segmented controls. Work mode cards: - Two side-by-side cards. - Each card: `330px x 284px`. - Radius: `12.5px`. - Selected background: `rgba(255, 255, 255, 0.08)`. - Unselected background: `rgb(24, 24, 24)`. - Unselected border: `1px rgba(255, 255, 255, 0.082)`. - Class pattern: `cursor-interaction flex min-h-[284px] w-full min-w-0 flex-col items-center`. Switches: - Switch button size: `32px x 20px`. - Text around switches uses `12px`. - Switch buttons report transparent background at the outer button level; the visual track/thumb is inside child elements. - Focus class: `focus-visible:ring-2`. - Aria labels carry the setting names, for example: - `Default permissions are always shown` - `Show Auto-review in the composer` - `Show Full access in the composer` - `Prevent sleep while running` - `Enable ambient suggestions` - `Enable permission notifications` - `Enable question notifications` Dropdown/select-like buttons: - Width: often `240px`. - Height: `28px`. - Radius: `12.5px`. - Background: `oklab(0.999994 0.0000455678 0.0000200868 / 0.05)`. - Border is reserved but transparent: `1px rgba(0, 0, 0, 0)`. - Text size: `13px`, line-height `18px`. - Examples: `VS Code`, `Auto Detect`, `Standard`, `Only when unfocused`. Small action buttons: - `Set` buttons are `38px x 28px`. - Same radius/background/font as dropdown buttons. Segmented pills: - Height: `24px`. - Radius: `9999px`. - Text size: `12px`, line-height `18px`. - Selected background: `oklab(0.999994 0.0000455678 0.0000200868 / 0.05)`. - Unselected background: transparent. - Examples: `Queue` / `Steer`, `Inline` / `Detached`. ## Settings: Appearance Appearance adds theme segmented controls, theme import/copy actions, code theme select, swatches, and sliders. Theme segmented control: - Buttons: `Light`, `Dark`, `System`. - Height: `24px`. - Radius: `9999px`. - Text size: `12px`, line-height `18px`. - Selected `Dark` background: `oklab(0.999994 0.0000455678 0.0000200868 / 0.05)`. - Unselected buttons are transparent. Theme actions: - `Import`: `58px x 28px`. - `Copy theme`: `91px x 28px`. - Radius: `12.5px`. - Transparent background and transparent reserved border. - Text size: `13px`, line-height `18px`. Code theme selector: - Example: `Aa Codex`. - Size: `240px x 28px`. - Background: `oklab(0.999994 0.0000455678 0.0000200868 / 0.05)`. - Radius: `12.5px`. - Box shadow includes a tiny `0 1px 2px -1px rgba(0,0,0,0.08)`. Color swatches: - Small swatch buttons measured at `14px x 14px`. - Background color carries the swatch value, for example accent green/blue. - Swatches are much smaller than toolbar buttons and are embedded in rows. ## Settings: Plugin Panels Browser Use and Computer Use settings use the same plugin panel pattern: - Header block: transparent, `672px` wide. - Section groups are transparent and stacked with `var(--padding-panel)`. - Plugin summary cards use: - `border-token-border/40` - `rounded-2xl` - `border` - `p-2.5` - `gap-2.5` - `transition` - Try/action icon button: - `28px x 28px`. - Radius: `10px`. - Transparent background and transparent reserved border. This is a quieter, smaller card style than Automation templates. ## Settings: Archived Chats Archived chats is a list surface: - Content column: `672px`. - List section uses `flex flex-col gap-2`. - Rows are transparent sections rather than cards. - Row actions use standard 28px buttons. - `Unarchive` button: - Size: `79px x 28px`. - Background: `oklab(0.999994 0.0000455678 0.0000200868 / 0.05)`. - Radius: `12.5px`. - Text size: `13px`, line-height `18px`. - Transparent reserved border. ## Settings: Usage Usage uses transparent sections with progress/limit content and standard actions. Observed sections: - `General usage limits` - `GPT-5.3-Codex-Spark usage limits` - `Credit` Section layout: - Section width: `672px`. - Usage limit sections measured `672px x 173px`. - Credit section measured `672px x 189px`. - Sections are transparent; progress values and row text provide structure. Actions: - `Purchase`: `74px x 28px`. - `Settings`: `68px x 28px`. - Background: `oklab(0.999994 0.0000455678 0.0000200868 / 0.05)`. - Radius: `12.5px`. - Text size: `13px`, line-height `18px`. Links: - Links can use muted secondary text rather than blue when they are ancillary. - Example `Doc`: `text-token-text-secondary hover:text-token-text-primary`. ## Practical Replication Rules 1. Use semantic tokens/classes first: foreground, description foreground, border, list hover, fog, input background. 2. Keep controls compact: `28px` for toolbar/composer controls, `30px` for nav rows. 3. Reserve border space with transparent borders to avoid hover layout shift. 4. Use `12.5px` radii for rows and split controls; use full pill radius for composer footer controls. 5. Use gradients only for resize handles, overflow fades, or masks. 6. Use `0.5px` translucent rings for major surfaces instead of strong 1px borders. 7. Keep text at `12px` or `13px` for operational UI. 8. Use `min-w-0`, `truncate`, and mask fades anywhere row actions can overlap labels. 9. Use `30px` radius only for large selectable prompt/template cards. 10. In settings, keep the content column at about `672px` and let controls carry the visual framing.