/*
 * SplitFlap web design tokens (THEME-1..5, THEME-2, WEB-1)
 *
 * Mirrors Sources/SplitFlapUI/SplitFlapTheme.swift and spec/design/design-language.md.
 * Keep hex values in sync with the Swift source of truth — the web client must not drift.
 *
 * Token families:
 *   --sf-accent-*     signage amber (THEME-4), light/dark pair + onAccent
 *   --sf-board-*      constant Solari palette (THEME-2), never mode-dependent
 *   --sf-space-*      4-pt spacing grid (THEME-1): xs 4 · sm 8 · md 12 · lg 16 · xl 24 · xxl 32
 *   --sf-radius-*     module 4 · card 12 · button capsule (THEME-1)
 *   --sf-type-*       semantic type scale (THEME-5); wordmark + mono stay monospaced
 *   --sf-chrome-*     adaptive chrome via system semantic colors (Canvas, CanvasText, GrayText)
 *
 * Light/dark: chrome follows the system appearance; the board stage stays constant dark.
 */

:root {
  color-scheme: light dark;

  /* Accent — signage amber (THEME-4) */
  --sf-accent-light: #c7861b;
  --sf-accent-dark: #e8a93c;
  --sf-on-accent: #1a1a15;
  --sf-accent: light-dark(var(--sf-accent-light), var(--sf-accent-dark));

  /* Board — constant Solari (THEME-2) */
  --sf-board-carcass: #1a1a15;
  --sf-board-flap: #e9e4d6;
  --sf-board-glyph: #1a1a15;
  --sf-board-seam: #0c0c0a;
  --sf-board-stage: #0e0e0c;
  --sf-board-amber-detail: #e8a93c;

  /* Spacing — 4-pt grid (THEME-1) */
  --sf-space-xs: 4px;
  --sf-space-sm: 8px;
  --sf-space-md: 12px;
  --sf-space-lg: 16px;
  --sf-space-xl: 24px;
  --sf-space-xxl: 32px;

  /* Radii (THEME-1) */
  --sf-radius-module: 4px;
  --sf-radius-card: 12px;
  --sf-radius-button: 9999px;

  /* Typography — system San Francisco scale (THEME-5) */
  --sf-font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --sf-font-mono: ui-monospace, "SF Mono", Menlo, monospace;
  --sf-type-large-title-size: 2.125rem;
  --sf-type-large-title-weight: 700;
  --sf-type-title-size: 1.375rem;
  --sf-type-title-weight: 600;
  --sf-type-headline-size: 1.0625rem;
  --sf-type-headline-weight: 600;
  --sf-type-body-size: 1rem;
  --sf-type-callout-size: 0.9375rem;
  --sf-type-caption-size: 0.75rem;

  /* Chrome — system semantic colors (adaptive) */
  --sf-chrome-bg: Canvas;
  --sf-chrome-text: CanvasText;
  --sf-chrome-muted: GrayText;
  --sf-chrome-border: color-mix(in srgb, CanvasText 12%, transparent);
  --sf-chrome-card: light-dark(
    color-mix(in srgb, Canvas 88%, CanvasText),
    color-mix(in srgb, Canvas 92%, CanvasText)
  );
  --sf-chrome-field: Field;
  --sf-chrome-error: light-dark(#b00020, #ff8a9a);
  --sf-chrome-success: light-dark(#1f6b3a, #7dd99a);

  /* Legacy aliases consumed by existing markup */
  --bg: var(--sf-chrome-bg);
  --card: var(--sf-chrome-card);
  --text: var(--sf-chrome-text);
  --muted: var(--sf-chrome-muted);
  --accent: var(--sf-accent);
  --accent-text: var(--sf-on-accent);
  --border: var(--sf-chrome-border);
  --error: var(--sf-chrome-error);
  --success: var(--sf-chrome-success);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: var(--sf-font-sans);
  font-size: var(--sf-type-body-size);
  background: var(--sf-chrome-bg);
  color: var(--sf-chrome-text);
  line-height: 1.5;
}

a {
  color: var(--sf-accent);
}

/* Typography roles (THEME-5) */

.type-large-title,
h1 {
  margin: 0 0 var(--sf-space-sm);
  font-size: var(--sf-type-large-title-size);
  font-weight: var(--sf-type-large-title-weight);
  line-height: 1.15;
}

.type-title {
  font-size: var(--sf-type-title-size);
  font-weight: var(--sf-type-title-weight);
  line-height: 1.2;
}

.type-headline,
.board-section-title {
  font-size: var(--sf-type-headline-size);
  font-weight: var(--sf-type-headline-weight);
  line-height: 1.25;
}

.type-body {
  font-size: var(--sf-type-body-size);
}

.type-callout,
.field-label,
.feedback {
  font-size: var(--sf-type-callout-size);
}

.type-caption,
.eyebrow {
  font-size: var(--sf-type-caption-size);
}

.wordmark {
  font-family: var(--sf-font-mono);
  font-size: var(--sf-type-large-title-size);
  font-weight: var(--sf-type-large-title-weight);
  letter-spacing: -0.02em;
}

.mono,
.code-pill {
  font-family: var(--sf-font-mono);
}

/* Site chrome */

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--sf-space-lg);
  padding: var(--sf-space-lg) var(--sf-space-xl);
  border-bottom: 1px solid var(--sf-chrome-border);
  background: var(--sf-chrome-bg);
}

.brand {
  text-decoration: none;
  color: var(--sf-chrome-text);
}

.site-nav {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sf-space-lg);
  align-items: center;
}

.site-nav a {
  text-decoration: none;
  color: var(--sf-chrome-muted);
  font-size: var(--sf-type-callout-size);
}

.site-nav a.nav-active,
.site-nav a:hover {
  color: var(--sf-chrome-text);
}

.link-button {
  border: 0;
  background: none;
  color: var(--sf-chrome-muted);
  cursor: pointer;
  font: inherit;
  font-size: var(--sf-type-callout-size);
}

.link-button:hover {
  color: var(--sf-chrome-text);
}

/* Layout */

.container {
  width: min(100%, 40rem);
  margin: 0 auto;
  padding: var(--sf-space-xxl) var(--sf-space-xl) calc(var(--sf-space-xxl) + var(--sf-space-lg));
}

/* Card + hero patterns */

.card {
  background: var(--sf-chrome-card);
  border: 1px solid var(--sf-chrome-border);
  border-radius: var(--sf-radius-card);
  padding: var(--sf-space-xl);
}

.hero {
  text-align: center;
}

.lede,
.muted {
  color: var(--sf-chrome-muted);
}

.eyebrow {
  margin: 0 0 var(--sf-space-xs);
}

/* Forms */

.field {
  display: block;
  margin: var(--sf-space-xl) 0 var(--sf-space-md);
}

.field-label {
  display: block;
  margin-bottom: var(--sf-space-xs);
  color: var(--sf-chrome-muted);
}

textarea {
  width: 100%;
  min-height: 7rem;
  padding: var(--sf-space-md);
  border-radius: var(--sf-radius-card);
  border: 1px solid var(--sf-chrome-border);
  background: var(--sf-chrome-field);
  color: var(--sf-chrome-text);
  font: inherit;
  resize: vertical;
}

textarea:focus-visible {
  outline: 2px solid var(--sf-accent);
  outline-offset: 2px;
}

.feedback {
  min-height: 1.25rem;
}

.actions {
  margin-top: var(--sf-space-lg);
}

/* Primary actions — StationButtonStyle analogue (THEME-4) */

button,
.cta,
.secondary-link {
  display: inline-block;
}

button.primary,
.cta {
  border: 0;
  border-radius: var(--sf-radius-button);
  padding: var(--sf-space-md) var(--sf-space-xl);
  background: var(--sf-accent);
  color: var(--sf-on-accent);
  font-weight: var(--sf-type-headline-weight);
  text-decoration: none;
  cursor: pointer;
}

button.primary:hover,
.cta:hover {
  filter: brightness(1.05);
}

button.primary:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.secondary-link {
  margin: var(--sf-space-md) 0 var(--sf-space-lg);
}

/* Board stage — constant dark backdrop for demos/previews (THEME-2) */

.board-stage {
  background: var(--sf-board-stage);
  color: var(--sf-board-flap);
  border-radius: var(--sf-radius-card);
  padding: var(--sf-space-xl);
}

/* Invite + send surfaces */

.code-pill {
  display: inline-block;
  margin: var(--sf-space-lg) 0;
  padding: var(--sf-space-md) var(--sf-space-lg);
  border-radius: var(--sf-radius-card);
  background: color-mix(in srgb, var(--sf-chrome-text) 10%, transparent);
  font-size: 1.4rem;
  letter-spacing: 0.12em;
  user-select: all;
}

.board-list {
  margin-top: var(--sf-space-lg);
}

.board-section + .board-section {
  margin-top: var(--sf-space-xl);
}

.board-section-title {
  margin: 0 0 var(--sf-space-md);
  color: var(--sf-chrome-muted);
}

.board-section-list {
  display: grid;
  gap: var(--sf-space-md);
}

.board-link {
  display: block;
  padding: var(--sf-space-md) var(--sf-space-lg);
  border-radius: var(--sf-radius-card);
  border: 1px solid var(--sf-chrome-border);
  text-decoration: none;
  color: inherit;
}

.board-link:hover {
  border-color: var(--sf-accent);
}

.board-link small {
  color: var(--sf-chrome-muted);
}

.error {
  color: var(--sf-chrome-error);
}

.success-banner {
  margin-top: var(--sf-space-lg);
  padding: var(--sf-space-md) var(--sf-space-lg);
  border-radius: var(--sf-radius-card);
  background: color-mix(in srgb, var(--sf-chrome-success) 12%, transparent);
  color: var(--sf-chrome-success);
}

.sign-in-button {
  width: 240px;
  max-width: 100%;
  height: 44px;
  margin: var(--sf-space-xl) auto 0;
}

/* Marketing landing (WEB-1 Phase A) */

.landing-page {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.site-header--landing .site-nav a {
  font-weight: var(--sf-type-headline-weight);
}

.landing {
  width: min(100%, 52rem);
  margin: 0 auto;
  padding: var(--sf-space-xxl) var(--sf-space-xl) var(--sf-space-xl);
}

.landing .hero {
  text-align: center;
  margin-bottom: var(--sf-space-xxl);
}

.landing .hero .lede {
  max-width: 36rem;
  margin: 0 auto var(--sf-space-xl);
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sf-space-md);
  justify-content: center;
  align-items: center;
}

.cta-secondary {
  display: inline-block;
  border: 1px solid var(--sf-chrome-border);
  border-radius: var(--sf-radius-button);
  padding: var(--sf-space-md) var(--sf-space-xl);
  background: transparent;
  color: var(--sf-chrome-text);
  font-weight: var(--sf-type-headline-weight);
  text-decoration: none;
}

.cta-secondary:hover {
  border-color: var(--sf-accent);
  color: var(--sf-accent);
}

.landing-demo {
  text-align: center;
  margin-bottom: var(--sf-space-xxl);
}

.demo-caption {
  margin: var(--sf-space-lg) 0 0;
  color: color-mix(in srgb, var(--sf-board-flap) 72%, transparent);
}

.board-preview {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--sf-space-xs);
}

.board-preview-row {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--sf-space-xs);
}

.flap {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 1.75rem;
  height: 2.25rem;
  padding: 0 var(--sf-space-xs);
  border-radius: var(--sf-radius-module);
  background: var(--sf-board-flap);
  color: var(--sf-board-glyph);
  font-family: var(--sf-font-mono);
  font-size: var(--sf-type-headline-size);
  font-weight: var(--sf-type-headline-weight);
  box-shadow: inset 0 -1px 0 var(--sf-board-seam);
}

.flap--space {
  opacity: 0.35;
}

/* Animated landing demo modules (WEB-DEMO) — mirrors ModuleFlipPose / SplitFlapModuleView */

.flap-module {
  --flap-module-height: 2.25rem;
  display: inline-block;
  width: 1.75rem;
  height: var(--flap-module-height);
  vertical-align: top;
}

.flap-module__body {
  position: relative;
  display: block;
  width: 100%;
  height: 100%;
  border-radius: var(--sf-radius-module);
  background: var(--sf-board-flap);
  color: var(--sf-board-glyph);
  box-shadow: inset 0 -1px 0 var(--sf-board-seam);
  perspective: 400px;
  transform-style: preserve-3d;
  overflow: hidden;
}

.flap-static {
  position: absolute;
  inset: 0;
}

.flap-half {
  position: absolute;
  left: 0;
  right: 0;
  height: 50%;
  overflow: hidden;
}

.flap-half--top {
  top: 0;
}

.flap-half--bottom {
  bottom: 0;
}

/* Full-height glyph clipped per half — flex-centered like SplitFlapModuleFlapHalf */
.flap-glyph {
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  height: var(--flap-module-height, 2.25rem);
  font-family: var(--sf-font-mono);
  font-size: calc(var(--flap-module-height, 2.25rem) * 0.62);
  font-weight: var(--sf-type-headline-weight);
  line-height: 1;
  text-align: center;
}

.flap-half--bottom .flap-glyph,
.flap-leaf--bottom .flap-glyph {
  top: calc(var(--flap-module-height, 2.25rem) * -0.5);
}

.flap-leaf {
  position: absolute;
  left: 0;
  right: 0;
  height: 50%;
  overflow: hidden;
  transform-style: preserve-3d;
  backface-visibility: hidden;
  background: var(--sf-board-flap);
}

.flap-leaf--top {
  top: 0;
  transform-origin: bottom center;
}

.flap-leaf--bottom {
  bottom: 0;
  transform-origin: top center;
}

.flap-seam {
  position: absolute;
  left: 0;
  right: 0;
  top: 50%;
  height: 1px;
  margin-top: -1px;
  background: var(--sf-board-seam);
  pointer-events: none;
}

@media (prefers-reduced-motion: reduce) {
  .landing-demo .demo-caption::after {
    content: " (animation paused for reduced motion)";
  }
}

.story-grid {
  display: grid;
  gap: var(--sf-space-lg);
  margin-bottom: var(--sf-space-xxl);
}

@media (min-width: 42rem) {
  .story-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.story-card h2 {
  margin: 0 0 var(--sf-space-sm);
}

.story-card p {
  margin: 0;
  color: var(--sf-chrome-muted);
}

.sign-in-panel {
  text-align: center;
  margin-bottom: var(--sf-space-xl);
}

.sign-in-panel h2 {
  margin: 0 0 var(--sf-space-sm);
}

.sign-in-panel .lede {
  margin-bottom: var(--sf-space-lg);
}

.site-footer {
  margin-top: auto;
  display: flex;
  flex-wrap: wrap;
  gap: var(--sf-space-md) var(--sf-space-xl);
  align-items: center;
  justify-content: space-between;
  padding: var(--sf-space-xl);
  border-top: 1px solid var(--sf-chrome-border);
  font-size: var(--sf-type-callout-size);
}

.footer-nav {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--sf-space-sm);
}

.footer-nav a {
  color: var(--sf-chrome-muted);
  text-decoration: none;
}

.footer-nav a:hover {
  color: var(--sf-chrome-text);
}

.footer-sep {
  color: var(--sf-chrome-muted);
}

.footer-app-link {
  color: var(--sf-accent);
  text-decoration: none;
  font-weight: var(--sf-type-headline-weight);
}

.footer-app-link:hover {
  text-decoration: underline;
}

@media (max-width: 36rem) {
  .site-header {
    padding: var(--sf-space-md) var(--sf-space-lg);
  }

  .container {
    padding: var(--sf-space-xl) var(--sf-space-lg) var(--sf-space-xxl);
  }

  .card {
    padding: var(--sf-space-lg);
  }

  h1,
  .type-large-title,
  .wordmark {
    font-size: 1.75rem;
  }
}

/* Try-compose (WEB-TRY) */

.try-compose .try-preview {
  margin: var(--sf-space-xl) 0;
}

.field-select {
  width: 100%;
  margin-top: var(--sf-space-xs);
  padding: var(--sf-space-md);
  border: 1px solid var(--sf-chrome-border);
  border-radius: var(--sf-radius-card);
  background: var(--sf-chrome-field);
  color: var(--sf-chrome-text);
  font: inherit;
}

.try-auth-panel {
  margin-top: var(--sf-space-xl);
  padding-top: var(--sf-space-xl);
  border-top: 1px solid var(--sf-chrome-border);
  text-align: center;
}

.try-auth-panel h2 {
  margin: 0 0 var(--sf-space-sm);
}

.try-auth-panel .actions {
  margin-top: var(--sf-space-lg);
}

a.cta.disabled,
a.cta[aria-disabled="true"] {
  opacity: 0.45;
  pointer-events: none;
}

.info-banner {
  margin-bottom: var(--sf-space-lg);
  padding: var(--sf-space-md) var(--sf-space-lg);
  border-radius: var(--sf-radius-card);
  background: color-mix(in srgb, var(--sf-accent) 12%, transparent);
  color: var(--sf-chrome-text);
}

.info-banner strong {
  display: block;
  margin-bottom: var(--sf-space-xs);
}

.info-banner--muted {
  background: color-mix(in srgb, var(--sf-chrome-muted) 10%, transparent);
}