@import "tailwindcss";

/* Class-based dark mode (toggled on <html> by the theme script). */
@custom-variant dark (&:where(.dark, .dark *));

@theme {
  /* Navy-tinted neutral scale — sampled from the app icon. ---------------- */
  --color-frost-50: #f5f8fd;
  --color-frost-100: #eaf0fa;
  --color-frost-200: #d9e3f3;
  --color-frost-300: #c2cfe4;
  --color-frost-400: #92a3c0;
  --color-frost-500: #6a7c9b;
  --color-frost-600: #4e5f7d;
  --color-frost-700: #3c4b66;
  --color-frost-800: #2b3752;
  --color-frost-900: #1d2740;
  --color-frost-950: #0e1526;

  /* Accent: glacier cyan to ice blue — focus rings, links, highlights. ---- */
  --color-accent-50: #ecf9ff;
  --color-accent-100: #d6f1ff;
  --color-accent-200: #b0e5ff;
  --color-accent-300: #7dd4fc;
  --color-accent-400: #38bdf8;
  --color-accent-500: #0ea5e9;
  --color-accent-600: #0284c7;
  --color-accent-700: #0369a1;
  --color-accent-800: #075985;
  --color-accent-900: #0c4a6e;

  /* Aurora hues used only for the frosted backdrop wash. ----------------- */
  --color-aurora-mint: #9fe3d0;
  --color-aurora-sky: #9ccdf5;
  --color-aurora-lilac: #c3b6f0;
  --color-aurora-peach: #f6cdb4;

  --font-sans: -apple-system, BlinkMacSystemFont, ui-sans-serif, system-ui,
    "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif,
    "Apple Color Emoji", "Segoe UI Emoji", "Noto Color Emoji";

  --shadow-frost: 0 14px 34px -22px rgb(13 13 13 / 0.28);
  --shadow-lift: 0 4px 14px -8px rgb(13 13 13 / 0.18);
  --shadow-hairline: 0 1px 0 0 rgb(13 13 13 / 0.04);

  --animate-float: float 11s ease-in-out infinite;
  --animate-pop: pop 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
  --animate-wiggle: wiggle 0.4s ease-in-out;
  --animate-rise: rise 0.4s cubic-bezier(0.22, 1, 0.36, 1) both;
  --animate-sheet: sheet 0.32s cubic-bezier(0.22, 1, 0.36, 1) both;
}

@keyframes float {
  0%, 100% { transform: translate3d(0, 0, 0) scale(1) }
  50% { transform: translate3d(0, -18px, 0) scale(1.04) }
}
@keyframes pop {
  0% { transform: scale(0.92) }
  60% { transform: scale(1.02) }
  100% { transform: scale(1) }
}
@keyframes wiggle {
  0%, 100% { transform: translateX(0) }
  25% { transform: translateX(-5px) }
  75% { transform: translateX(5px) }
}
@keyframes rise {
  from { opacity: 0; transform: translateY(10px) }
  to { opacity: 1; transform: translateY(0) }
}
@keyframes sheet {
  from { opacity: 0; transform: translateY(24px) }
  to { opacity: 1; transform: translateY(0) }
}

/* ---------------------------------------------------------------------------
   Theme tokens.
   Light: ChatGPT-ish neutral (page #ffffff, sidebar #f9f9f9, border #e5e5e5).
   Dark:  page #212121, sidebar #171717, surfaces #2f2f2f, borders rgba(255,255,255,.1).
   Text tiers are picked to clear WCAG AA (4.5:1) on their own background.
   --------------------------------------------------------------------------- */
:root {
  color-scheme: light;
  --page: #eef5fd;
  --sidebar: #ffffff;
  --surface: #ffffff;
  --surface-raised: #ffffff;
  --surface-strong: rgb(255 255 255 / 0.72);   /* nested glass: inputs, chips */
  --card-hover-bg: rgb(255 255 255 / 0.72);
  --surface-sunken: rgb(12 32 62 / 0.06);
  --hairline: #d5e4f4;
  --card-border: var(--glass-border);
  --sidebar-divider: rgb(255 255 255 / 0.75);
  --hairline-soft: rgb(12 32 62 / 0.08);
  --glass-tint: rgb(255 255 255 / 0.55);
  --text: #0b1830;          /* 16.6:1 on #eef5fd */
  --text-muted: #46586f;    /* 6.6:1 on light glass */
  --text-subtle: #566a84;   /* 5.0:1 on light glass */
  --hover: rgb(12 32 62 / 0.05);
  --focus: #0ea5e9;

  /* Frosted ice glass — one shared recipe for every large surface. */
  --glass-bg: rgb(255 255 255 / 0.55);
  --glass-border: rgb(255 255 255 / 0.8);
  --glass-highlight: rgb(255 255 255 / 0.85);
  --glass-shadow: 0 20px 50px -20px rgb(30 64 175 / 0.35);
  --glass-solid-bg: rgb(255 255 255 / 0.8);    /* question card: more opaque */
  --glass-fallback: rgb(247 251 255 / 0.97);   /* no backdrop-filter */
  --nav-active-bg: rgb(255 255 255 / 0.75);
  --nav-active-border: rgb(56 189 248 / 0.5);
  /* API-key gate: cool near-white stage with soft blue glows, tinted input. */
  --gate-card: rgb(255 255 255 / 0.62);
  --gate-callout-bg: rgb(255 255 255 / 0.55);
  --gate-callout-border: rgb(56 189 248 / 0.32);
  --field: rgb(255 255 255 / 0.66);
  --field-border: rgb(255 255 255 / 0.9);
  --shadow-gate: 0 28px 70px -36px rgb(14 21 40 / 0.3), 0 1px 2px rgb(14 21 40 / 0.05);
  /* Install sheet: light variant (dark is the default, see .dark). */
  --install-sheet: rgb(255 255 255 / 0.6);
  --install-card: rgb(255 255 255 / 0.7);
  --install-chip: rgb(255 255 255 / 0.55);
  --install-border: rgb(255 255 255 / 0.8);
  --shadow-card: 0 1px 2px rgb(14 21 40 / 0.06), 0 1px 3px rgb(14 21 40 / 0.04);
  --card-shadow: 0 1px 2px rgb(14 21 40 / 0.05), 0 5px 14px -6px rgb(14 21 40 / 0.12);
  --shadow-card-hover: 0 24px 60px -24px rgb(30 64 175 / 0.45), 0 2px 6px rgb(30 64 175 / 0.12);
}

.dark {
  color-scheme: dark;
  --page: #0a1120;
  --sidebar: #0b1524;
  --surface: #16233a;
  --surface-raised: #1d2c47;
  --surface-strong: rgb(255 255 255 / 0.08);
  --card-hover-bg: rgb(255 255 255 / 0.1);
  --surface-sunken: rgb(255 255 255 / 0.07);
  --hairline: rgb(255 255 255 / 0.12);
  --card-border: var(--glass-border);
  --sidebar-divider: rgb(255 255 255 / 0.12);
  --hairline-soft: rgb(255 255 255 / 0.08);
  --glass-tint: rgb(255 255 255 / 0.06);
  --text: #e8f0ff;          /* 16.3:1 on #0a1120 */
  --text-muted: #b3c4e0;    /* 10.1:1 */
  --text-subtle: #90a4c6;   /* 6.9:1  */
  --hover: rgb(255 255 255 / 0.07);
  --focus: #38bdf8;

  /* Frosted ice glass — dark: barely-there tint, brighter rim. */
  --glass-bg: rgb(255 255 255 / 0.06);
  --glass-border: rgb(255 255 255 / 0.12);
  --glass-highlight: rgb(255 255 255 / 0.25);
  --glass-shadow: 0 20px 50px -20px rgb(30 64 175 / 0.35);
  --glass-solid-bg: rgb(255 255 255 / 0.1);
  --glass-fallback: rgb(16 26 45 / 0.97);
  --nav-active-bg: rgb(56 189 248 / 0.14);
  --nav-active-border: rgb(56 189 248 / 0.4);
  /* API-key gate: navy stage with the icon's blue glows, raised input. */
  --gate-card: rgb(255 255 255 / 0.06);
  --gate-callout-bg: rgb(255 255 255 / 0.06);
  --gate-callout-border: rgb(56 189 248 / 0.3);
  --field: rgb(255 255 255 / 0.07);
  --field-border: rgb(255 255 255 / 0.14);
  --shadow-gate: 0 30px 80px -40px rgb(0 0 0 / 0.85), 0 1px 2px rgb(0 0 0 / 0.4);
  /* Install sheet: layered dark surfaces (default theme for the sheet). */
  --install-sheet: rgb(255 255 255 / 0.06);
  --install-card: rgb(255 255 255 / 0.07);
  --install-chip: rgb(255 255 255 / 0.1);
  --install-border: rgb(255 255 255 / 0.14);
  --shadow-card: 0 1px 2px rgb(0 0 0 / 0.25);
  --card-shadow: var(--shadow-card);
  --shadow-card-hover: 0 24px 60px -24px rgb(30 64 175 / 0.55), 0 2px 8px rgb(0 0 0 / 0.3);
}

/* Ice scene tokens: the fixed layered background behind everything. */
:root {
  --ice-base-top: #f4f9ff;
  --ice-base-bottom: #e6f1fb;
  --ice-blob-opacity: 0.18;
  --ice-orb-opacity: 0.55;
  --ice-grain-opacity: 0.05;
}
.dark {
  --ice-base-top: #070b16;
  --ice-base-bottom: #0c1426;
  --ice-blob-opacity: 0.4;
  --ice-orb-opacity: 0.8;
  --ice-grain-opacity: 0.045;
}

html,
body {
  height: 100%;
  overscroll-behavior: none;
}

body {
  font-family: var(--font-sans);
  -webkit-tap-highlight-color: transparent;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  /* Matches the backdrop so iOS rubber-banding never shows a seam. */
  background-color: var(--page);
  color: var(--text);
  overscroll-behavior-y: none;
}

.dark body {
  color: var(--color-frost-100);
}

/* The page backdrop now lives in ONE viewport-fixed layer (see .app-backdrop)
   so it can never stretch, scroll or be clipped by a content column.
   `.frost-bg` stays as a transparent wrapper for pages that used it. */
.frost-bg {
  background: transparent;
}

/* The key gate rides on the shared ice scene (see .ice-scene). */

/* The fixed ice scene: navy/pale base, drifting glacier blobs, glossy ice
   orbs and a whisper of grain. Purely decorative. */
.ice-scene {
  position: fixed;
  inset: 0;
  z-index: -1;
  overflow: hidden;
  pointer-events: none;
  background: linear-gradient(180deg, var(--ice-base-top) 0%, var(--ice-base-bottom) 100%);
}

.ice-blob {
  position: absolute;
  border-radius: 50%;
  opacity: var(--ice-blob-opacity);
  will-change: transform;
  /* No filter: blur() here on purpose. A radial gradient fading to
     transparent is already a soft blob, and blurring a huge layer that is
     also being animated forces a re-rasterisation every frame (measured
     150ms vs 33ms per frame in a software renderer). The falloff stops below
     keep the same softness. */
}
.ice-blob-a {
  width: 52vw; height: 52vw; min-width: 24rem; min-height: 24rem;
  top: -14vh; left: -10vw;
  background: radial-gradient(circle, rgb(56 189 248 / 0.9) 0%, rgb(56 189 248 / 0.45) 38%, transparent 72%);
  animation: ice-drift-a 44s ease-in-out infinite;
}
.ice-blob-b {
  width: 46vw; height: 46vw; min-width: 22rem; min-height: 22rem;
  top: 4vh; right: -12vw;
  background: radial-gradient(circle, rgb(96 165 250 / 0.9) 0%, rgb(96 165 250 / 0.45) 38%, transparent 72%);
  animation: ice-drift-b 52s ease-in-out infinite;
}
.ice-blob-c {
  width: 48vw; height: 48vw; min-width: 22rem; min-height: 22rem;
  bottom: -16vh; left: 14vw;
  background: radial-gradient(circle, rgb(129 140 248 / 0.9) 0%, rgb(129 140 248 / 0.42) 38%, transparent 74%);
  animation: ice-drift-c 60s ease-in-out infinite;
}
.ice-blob-d {
  width: 34vw; height: 34vw; min-width: 16rem; min-height: 16rem;
  bottom: 2vh; right: 6vw;
  background: radial-gradient(circle, rgb(56 189 248 / 0.85) 0%, rgb(56 189 248 / 0.4) 38%, transparent 74%);
  animation: ice-drift-a 48s ease-in-out infinite reverse;
}

@keyframes ice-drift-a {
  0%, 100% { transform: translate3d(0, 0, 0) scale(1); }
  50% { transform: translate3d(4vw, 3vh, 0) scale(1.08); }
}
@keyframes ice-drift-b {
  0%, 100% { transform: translate3d(0, 0, 0) scale(1.05); }
  50% { transform: translate3d(-5vw, 4vh, 0) scale(1); }
}
@keyframes ice-drift-c {
  0%, 100% { transform: translate3d(0, 0, 0) scale(1); }
  50% { transform: translate3d(3vw, -4vh, 0) scale(1.1); }
}

/* Glossy ice orbs, placed so the glass panels blur them. */
.ice-orb {
  position: absolute;
  border-radius: 50%;
  opacity: var(--ice-orb-opacity);
  background: radial-gradient(
    circle at 30% 25%,
    rgb(255 255 255 / 0.95) 0%,
    rgb(191 227 255 / 0.55) 18%,
    rgb(96 165 250 / 0.35) 48%,
    rgb(37 99 235 / 0.45) 100%
  );
  box-shadow: 0 18px 40px -18px rgb(30 64 175 / 0.55), inset 0 -8px 18px -10px rgb(30 64 175 / 0.6);
}
.ice-orb-1 { width: 190px; height: 190px; top: 14%; left: 12%; }
.ice-orb-2 { width: 84px; height: 84px; top: 58%; left: 4%; }
.ice-orb-3 { width: 220px; height: 220px; bottom: -70px; right: 10%; }
.ice-orb-4 { width: 52px; height: 52px; top: 24%; right: 28%; }
.ice-orb-5 { width: 120px; height: 120px; bottom: 16%; left: 38%; }

/* Frosted grain over the whole scene. */
.ice-grain {
  position: absolute;
  inset: 0;
  opacity: var(--ice-grain-opacity);
  mix-blend-mode: overlay;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='180' height='180'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='3' stitchTiles='stitch'/%3E%3CfeColorMatrix type='saturate' values='0'/%3E%3C/filter%3E%3Crect width='180' height='180' filter='url(%23n)'/%3E%3C/svg%3E");
}

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

/* Phones: fewer, softer blobs so the drift animation stays cheap. Unlayered
   on purpose — layered rules would lose to the .ice-blob declarations above. */
@media (max-width: 1023px) {
  .ice-blob-c,
  .ice-blob-d,
  .ice-orb-4,
  .ice-orb-5 {
    display: none;
  }
  .ice-orb-1 { width: 120px; height: 120px; }
  .ice-orb-3 { width: 150px; height: 150px; }
}

@layer components {
/* Frosted ice glass ------------------------------------------------------
   One shared recipe for the large surfaces only: translucent tint, 24px
   blur, a bright rim, an inner top highlight and a blue-tinted shadow.
   Nested glass (chips, inputs) never adds a second blur layer. Tailwind's
   backdrop utilities emit the -webkit- prefix too (hand-written
   backdrop-filter gets minified to -webkit- only, which paints nothing). */
.glass-panel,
.card,
.sidebar-surface,
.study-chrome,
.tabbar,
.glass,
.gate-card {
  @apply backdrop-blur-xl backdrop-saturate-[1.4];
  background: var(--glass-bg);
  box-shadow: var(--glass-shadow), inset 0 1px 0 var(--glass-highlight);
}

.glass-panel {
  border: 1px solid var(--glass-border);
  border-radius: 1.5rem;
}

/* Nested glass: slightly more opaque than its parent, no extra blur. */
.glass-chip {
  background: var(--surface-sunken);
  border: 1px solid var(--glass-border);
}

/* More opaque glass for the study question card, where text must stay crisp. */
.glass-solid {
  background: var(--glass-solid-bg);
}
.glass-chip:hover {
  background: var(--hover);
}

.glass {
  border-bottom: 1px solid var(--glass-border);
}

/* Study-feed chrome (progress header + bottom pager): the same neutral
   surface as the cards, with a neutral border and shadow. */
.study-chrome {
  border: 1px solid var(--glass-border);
}

.card {
  border-radius: 1.5rem;                 /* 24px */
  border: 1px solid var(--glass-border);
}

.gate-card {
  border: 1px solid var(--glass-border);
  border-radius: 1.75rem;                /* 28px */
}

/* Blur is expensive on phones: halve it, and thin out the ice scene. */
@media (max-width: 1023px) {
  .glass-panel,
  .card,
  .sidebar-surface,
  .study-chrome,
  .tabbar,
  .glass,
  .gate-card {
    @apply backdrop-blur-lg;
  }
}

/* No backdrop-filter support: fall back to a more opaque surface. */
@supports not ((backdrop-filter: blur(1px)) or (-webkit-backdrop-filter: blur(1px))) {
  .glass-panel,
  .card,
  .sidebar-surface,
  .study-chrome,
  .tabbar,
  .glass,
  .gate-card {
    background: var(--glass-fallback);
  }
}

/* Opt-in hover lift for interactive cards (deck cards). Pointer devices only,
   so touch screens never get sticky hover states. */
.card-hover {
  transition: background-color 180ms ease, box-shadow 180ms ease, border-color 180ms ease, transform 180ms ease;
}
@media (hover: hover) and (pointer: fine) {
  .card-hover:hover {
    background: var(--card-hover-bg);
    border-color: var(--nav-active-border);
    box-shadow: var(--shadow-card-hover);
    transform: translateY(-2px);
  }
}
.card-hover:active {
  transform: translateY(0);
}

/* Inset grouped list ---------------------------------------------------- */
.list-group {
  border-radius: 1rem;
  @apply backdrop-blur-lg backdrop-saturate-150;
  background: color-mix(in oklab, var(--surface) 82%, transparent);
  border: 1px solid var(--hairline);
  overflow: hidden;
}
.list-group > * + * {
  border-top: 1px solid var(--hairline-soft);
}

/* iOS segmented control ------------------------------------------------- */
.segmented {
  display: flex;
  gap: 2px;
  padding: 3px;
  border-radius: 0.95rem;
  @apply backdrop-blur-sm;
  background: var(--surface-sunken);
  border: 1px solid var(--hairline);
}
.segmented > button {
  flex: 1;
  border-radius: 0.75rem;
  padding: 0.42rem 0.5rem;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-frost-700);
  transition: background-color 0.18s ease, color 0.18s ease, box-shadow 0.18s ease;
}
.dark .segmented > button {
  color: var(--color-frost-300);
}
.segmented > button[aria-pressed="true"],
.segmented > button[aria-checked="true"] {
  background-image: linear-gradient(135deg, #38bdf8 0%, #60a5fa 100%);
  color: #06111f;
  box-shadow: 0 6px 16px -8px rgb(56 189 248 / 0.7);
}
.dark .segmented > button[aria-pressed="true"],
.dark .segmented > button[aria-checked="true"] {
  background-image: linear-gradient(135deg, #38bdf8 0%, #60a5fa 100%);
  color: #06111f;
}

/* Ice gradient for progress bars and selected states. */
.grad-ice {
  background-image: linear-gradient(90deg, #38bdf8 0%, #60a5fa 100%);
}

/* Sheet grabber --------------------------------------------------------- */
.sheet-grabber {
  width: 36px;
  height: 5px;
  border-radius: 999px;
  background: var(--hairline-soft);
  margin: 0 auto 0.75rem;
}

.tabbar {
  border-top: 1px solid var(--glass-border);
}

/* Soft tinted chip for activity types (a hint of colour, not a rainbow) -- */
.tint-sky { background: linear-gradient(140deg, rgb(156 205 245 / 0.34), rgb(156 205 245 / 0.14)); color: #1c4e72 }
.tint-mint { background: linear-gradient(140deg, rgb(159 227 208 / 0.4), rgb(159 227 208 / 0.16)); color: #1d5c4c }
.tint-lilac { background: linear-gradient(140deg, rgb(195 182 240 / 0.4), rgb(195 182 240 / 0.16)); color: #47397f }
.tint-peach { background: linear-gradient(140deg, rgb(246 205 180 / 0.45), rgb(246 205 180 / 0.18)); color: #7d4522 }
.tint-rose { background: linear-gradient(140deg, rgb(246 178 190 / 0.4), rgb(246 178 190 / 0.16)); color: #7c2b3d }
.dark .tint-sky { background: linear-gradient(140deg, rgb(74 164 220 / 0.26), rgb(74 164 220 / 0.1)); color: #bfe2fb }
.dark .tint-mint { background: linear-gradient(140deg, rgb(88 201 173 / 0.26), rgb(88 201 173 / 0.1)); color: #bdf0e2 }
.dark .tint-lilac { background: linear-gradient(140deg, rgb(160 140 235 / 0.26), rgb(160 140 235 / 0.1)); color: #ddd5fb }
.dark .tint-peach { background: linear-gradient(140deg, rgb(230 160 118 / 0.26), rgb(230 160 118 / 0.1)); color: #fadfc9 }
.dark .tint-rose { background: linear-gradient(140deg, rgb(230 130 150 / 0.26), rgb(230 130 150 / 0.1)); color: #fbd5dd }

/* Sidebar surface: frosted navy glass with a real edge. */
/* Sidebar surface: one tall inset glass panel. */
.sidebar-surface {
  border: 1px solid var(--glass-border);
  border-radius: 1.5rem;
}

/* Sidebar nav rows */
.nav-row {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  width: 100%;
  border-radius: 0.625rem;
  padding: 0.5rem 0.625rem;
  font-size: 13.5px;
  font-weight: 500;
  color: var(--text-muted);
  transition: background-color 140ms ease, color 140ms ease;
}
.nav-row:hover {
  background: var(--hover);
  color: var(--text);
}
.nav-row[aria-current="page"],
.nav-row[aria-pressed="true"] {
  background: var(--nav-active-bg);
  color: var(--text);
  box-shadow: inset 0 0 0 1px var(--nav-active-border), inset 0 1px 0 var(--glass-highlight);
}

/* Shared CTA language: the icon's blue, with a deeper fill in light mode. */
.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  border-radius: 14px;
  background-image: linear-gradient(135deg, #1d4ed8 0%, #1a5fd0 55%, #0ea5e9 100%);
  color: #ffffff;
  font-weight: 500;
  box-shadow: 0 10px 24px -12px rgb(14 165 233 / 0.7);
  transition: box-shadow 180ms ease, filter 180ms ease, transform 160ms ease;
}
.btn-primary:hover {
  filter: brightness(1.07);
  box-shadow: 0 14px 32px -12px rgb(56 189 248 / 0.85);
}
.btn-primary:active { transform: scale(0.985); }
.dark .btn-primary {
  background-image: linear-gradient(135deg, #ffffff 0%, #bfe3ff 100%);
  color: #0b1220;
  box-shadow: 0 10px 26px -14px rgb(56 189 248 / 0.6);
}
.dark .btn-primary:hover {
  filter: brightness(1.03);
  box-shadow: 0 14px 34px -14px rgb(56 189 248 / 0.95);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  border-radius: 14px;
  background: var(--surface-strong);
  color: var(--text);
  border: 1px solid var(--glass-border);
  font-weight: 500;
  transition: background-color 160ms ease, border-color 160ms ease, transform 160ms ease;
}
.btn-secondary:hover {
  background: var(--hover);
  border-color: var(--nav-active-border);
}
.btn-secondary:active { transform: scale(0.985); }

.btn-ghost {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  border-radius: 14px;
  background: transparent;
  color: var(--text-muted);
  font-weight: 500;
  transition: background-color 160ms ease, color 160ms ease;
}
.btn-ghost:hover { background: var(--hover); color: var(--text); }

/* Difficulty: neutral pill, colour lives in the text only. */
.diff-easy { color: #16714f; }
.diff-medium { color: #7a5300; }
.diff-hard { color: #b4342f; }
.dark .diff-easy { color: #6fd3a8; }
.dark .diff-medium { color: #e3b341; }
.dark .diff-hard { color: #f08a84; }

/* Loading skeleton */
.skeleton {
  position: relative;
  overflow: hidden;
  background: var(--surface-sunken);
  border-radius: 0.75rem;
}
.skeleton::after {
  content: "";
  position: absolute;
  inset: 0;
  transform: translateX(-100%);
  background: linear-gradient(90deg, transparent, rgb(255 255 255 / 0.45), transparent);
  animation: shimmer 1.6s infinite;
}
.dark .skeleton::after {
  background: linear-gradient(90deg, transparent, rgb(255 255 255 / 0.06), transparent);
}
@keyframes shimmer {
  100% { transform: translateX(100%); }
}

.text-balance {
  text-wrap: balance;
}

/* Focus rings ------------------------------------------------------------ */
:where(button, a, input, textarea, [tabindex]):focus-visible {
  outline: 2.5px solid var(--color-accent-500);
  outline-offset: 2px;
  border-radius: 0.75rem;
}

/* Scrollbars ------------------------------------------------------------- */
.thin-scroll {
  scrollbar-width: thin;
  scrollbar-color: color-mix(in oklab, var(--color-frost-400) 55%, transparent) transparent;
}
.thin-scroll::-webkit-scrollbar { width: 8px; height: 8px }
.thin-scroll::-webkit-scrollbar-thumb {
  background: color-mix(in oklab, var(--color-frost-400) 45%, transparent);
  border-radius: 999px;
}
.no-scrollbar::-webkit-scrollbar { display: none }
.no-scrollbar { -ms-overflow-style: none; scrollbar-width: none }

/* Mobile safe areas ------------------------------------------------------ */
.pt-safe { padding-top: max(env(safe-area-inset-top), 0.75rem) }
.pb-safe { padding-bottom: max(env(safe-area-inset-bottom), 0.75rem) }
.pb-tabbar { padding-bottom: calc(env(safe-area-inset-bottom, 0px) + 5.25rem) }
.pb-cta { padding-bottom: calc(env(safe-area-inset-bottom, 0px) + 9rem) }

@media (display-mode: standalone) {
  .standalone-hide { display: none }
}
}

/* Mobile form fields ----------------------------------------------------- */
/* iOS Safari zooms the whole page when a focused field's text is under 16px
   (it ignores user-scalable=no for that). Deliberately unlayered so it wins
   over the per-component Tailwind sizes, and only on phone-sized screens. */
@media (max-width: 639px) {
  input:not([type="checkbox"]):not([type="radio"]):not([type="range"]),
  textarea,
  select {
    font-size: 16px;
  }
}

/* Reduced motion --------------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
}