@import "tailwindcss";

@custom-variant dark (&:is(.dark *));

/*
 * THE SKIN — wave 5. Design tokens, the single place to restyle the app.
 *
 * Mathematical soundness, per the owner's brief:
 *   - Tailwind's built-in 0.25rem (4px) spacing scale IS the rhythm — every
 *     padding/margin/gap in the app uses whole units of a 4px base.
 *   - The type scale below is a declared modular ladder (each --text-* token
 *     carries its own line-height); components never invent pixel sizes.
 *   - Radii ladder is 4 / 8 / 12 / 16px multiples of the 4px base.
 *   - Emphasis colors live in tokens (--lh-ink-strong / --lh-ink-italic) so a
 *     future settings UI reassigns them (configurable per the owner).
 */

/* Palette (owner's hexes): main #141414, raised #1C1C1C, edges #434343.
   Mono chrome = JetBrains Mono; prose = Source Sans 3; titles = CMU Serif. */
:root {
	--radius: 8px;
	--background: #141414;
	--foreground: #e6e6e6;
	--card: #1c1c1c;
	--card-foreground: #e6e6e6;
	--popover: #1c1c1c;
	--popover-foreground: #e6e6e6;
	--primary: #e6e6e6;
	--primary-foreground: #141414;
	--secondary: #1c1c1c;
	--secondary-foreground: #e6e6e6;
	--muted: #1c1c1c;
	--muted-foreground: #8d8d8d;
	--accent: #2a2a2a;
	--accent-foreground: #e6e6e6;
	--destructive: oklch(0.704 0.191 22.216);
	--border: #434343;
	--input: #434343;
	--ring: #8d8d8d;
	/* Emphasis coloring in teaching prose — ready for the settings UI. */
	--lh-ink-strong: #c96b4a;
	--lh-ink-italic: #6fa9d6;
	--lh-prose-size: 16.5px;
	--lh-prose-leading: 1.5;
}

/* The app is always dark (<html class="dark">); mirror the same values so
   the block stays coherent under Tailwind's variant. */
.dark {
	--background: #141414;
	--foreground: #e6e6e6;
	--card: #1c1c1c;
	--card-foreground: #e6e6e6;
	--popover: #1c1c1c;
	--popover-foreground: #e6e6e6;
	--primary: #e6e6e6;
	--primary-foreground: #141414;
	--secondary: #1c1c1c;
	--secondary-foreground: #e6e6e6;
	--muted: #1c1c1c;
	--muted-foreground: #8d8d8d;
	--accent: #2a2a2a;
	--accent-foreground: #e6e6e6;
	--destructive: oklch(0.704 0.191 22.216);
	--border: #434343;
	--input: #434343;
	--ring: #8d8d8d;
	--lh-ink-strong: #c96b4a;
	--lh-ink-italic: #6fa9d6;
	--lh-prose-size: 16.5px;
	--lh-prose-leading: 1.5;
}

/* CMU Serif bold (titles) — bundled local file, no CDN dependency. */
@font-face {
	font-family: "lh-cmu";
	src: url("/fonts/cmunbx.ttf") format("truetype");
	font-weight: 700;
	font-style: normal;
	font-display: swap;
}

@theme inline {
	/* Fonts: chrome = JetBrains Mono, prose = Source Sans 3, titles = CMU
	   Serif bold. The JetBrains/SourceSans variables attach in app/layout.tsx.
	   (owner, typography round) The Tailwind defaults are ALIASED to the app
	   fonts: `font-mono`/`font-sans` utilities would otherwise fall to the
	   SYSTEM stacks — a fourth font the app never chose — and streamdown's
	   code-block chrome + mermaid-error + demo-card all use them. */
	--font-ui: var(--font-jetbrains), ui-monospace, SFMono-Regular, monospace;
	--font-prose: var(--font-sans3), ui-sans-serif, system-ui, sans-serif;
	--font-title: "lh-cmu", serif;
	--font-mono: var(--font-jetbrains), ui-monospace, SFMono-Regular, monospace;
	--font-sans: var(--font-sans3), ui-sans-serif, system-ui, sans-serif;
	/* The modular type ladder — each size carries its own line-height.
	   Component sizes must pull from this ladder. */
	--text-xxs: 10px;
	--text-xxs--line-height: 1.4;
	--text-xs: 11px;
	--text-xs--line-height: 1.4;
	--text-sm: 12.5px;
	--text-sm--line-height: 1.4;
	--text-base: 14px;
	--text-base--line-height: 1.45;
	--text-lg: 16px;
	--text-lg--line-height: 1.45;
	--text-xl: 20px;
	--text-xl--line-height: 1.4;
	--text-2xl: 25px;
	--text-2xl--line-height: 1.3;
	--text-3xl: 32px;
	--text-3xl--line-height: 1.25;
	/* Radii ladder — 4/8/12/16 multiples of the 4px base. */
	--radius-sm: 4px;
	--radius-md: 8px;
	--radius-lg: 12px;
	--radius-xl: 16px;
	--radius: 8px;
	--color-background: var(--background);
	--color-foreground: var(--foreground);
	--color-card: var(--card);
	--color-card-foreground: var(--card-foreground);
	--color-popover: var(--popover);
	--color-popover-foreground: var(--popover-foreground);
	--color-primary: var(--primary);
	--color-primary-foreground: var(--primary-foreground);
	--color-secondary: var(--secondary);
	--color-secondary-foreground: var(--secondary-foreground);
	--color-muted: var(--muted);
	--color-muted-foreground: var(--muted-foreground);
	--color-accent: var(--accent);
	--color-accent-foreground: var(--accent-foreground);
	--color-destructive: var(--destructive);
	--color-border: var(--border);
	--color-input: var(--input);
	--color-ring: var(--ring);
}

* {
	border-color: var(--color-border);
}

body {
	background: var(--color-background);
	color: var(--color-foreground);
	font-family: var(--font-ui);
}

/* Teaching prose (the markdown renderer's container gets .lh-prose):
   Source Sans 3 with the size/leading tokens; emphasis color bound to
   the settings-ready tokens. */
.lh-prose {
	font-family: var(--font-prose);
	font-size: var(--lh-prose-size);
	line-height: var(--lh-prose-leading);
}

.lh-prose :where(strong, b) {
	color: var(--lh-ink-strong);
	font-weight: 700;
}

.lh-prose :where(em, i) {
	color: var(--lh-ink-italic);
}

/* Thin dark native scrollbar (app-wide): dark thumb, transparent track. */
* {
	scrollbar-width: thin;
	scrollbar-color: var(--color-border) transparent;
}

::-webkit-scrollbar {
	width: 8px;
	height: 8px;
}

::-webkit-scrollbar-track {
	background: transparent;
}

::-webkit-scrollbar-thumb {
	background: var(--color-border);
	border-radius: 8px;
}

::-webkit-scrollbar-thumb:hover {
	background: var(--color-muted-foreground);
}

/* Dock variant swap — quick fade/rise on content change; the shell's HEIGHT
   morph is separate (WAAPI in DockOverlay). Re-applied via class toggling, no
   remount, so collapsed-question state survives. */
@keyframes dock-variant-in {
	from {
		opacity: 0;
		transform: translateY(6px);
	}

	to {
		opacity: 1;
		transform: translateY(0);
	}
}

.dock-variant {
	animation: dock-variant-in 160ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

/* ============================================================
 * W3 — presentation fixes (appended 2026-08-22)
 * ============================================================ */

/* Streamdown's internal UI chrome (code blocks, tables, mermaid containers,
   copy/download buttons) is styled with Tailwind utilities living in its dist
 * bundle. Tailwind v4 never scans node_modules, so without this line those
 * classes are dead — code blocks and mermaid containers rendered unstyled.
 * (Streamdown README, "Tailwind CSS setup".) */
@source "../node_modules/streamdown/dist/*.js";

/* Token the streamdown utilities reference (code-block/mermaid chrome uses
 * bg-sidebar / border-sidebar): map it onto the app's card surface. */
@theme inline {
	--color-sidebar: var(--card);
}

/* Mermaid diagrams: keep wide charts inside the content column. Mermaid
 * inlines a px max-width on the svg, so !important is required to win. */
[data-streamdown="mermaid"] svg {
	max-width: 100% !important;
	height: auto !important;
}

/* Display math: long equations scroll instead of overflowing the column. */
.katex-display {
	overflow-x: auto;
	overflow-y: hidden;
}

/* ============================================================
 * Session status — the braille spinner (the one working indicator)
 * ============================================================ */

/* (owner, minimal-color round) Phase color-coding is RETIRED: phases only
   advance (every session ends in Teaching), so phase-as-signal was
   decoration; the --phase-* tokens and every phase-dot state are gone.
   What state deserved — "a turn is in flight" — is carried by MOTION
   alone: the terminal braille spinner (components/braille-spinner.tsx),
   monochrome, existing only while true. */

/* One keyframes, all ten frames: each frame <g> holds opacity 1 for its
   10% slice of the 800ms cycle and 0 elsewhere; frames stagger via
   positive animation-delay (frame k starts at k×80ms). Static contexts
   (SSR, reduced motion) show frame 0 — see the base rules below. */
@keyframes braille-frame {
	0%,
	10% {
		opacity: 1;
	}

	10.001%,
	100% {
		opacity: 0;
	}
}

.braille-frame {
	animation: braille-frame 800ms linear infinite;
	opacity: 0;
}

/* Static fallback: frame 0 (⠋) is the glyph a non-animated context shows. */
.braille-frame[data-frame="0"] {
	opacity: 1;
}

@media (prefers-reduced-motion: reduce) {
	.braille-frame {
		animation: none;
	}
}