/* ─── Design tokens ──────────────────────────────────────────────────────── */
:root {
  --col-primary:   #FFB84D;
  --col-sky:       #4DB8FF;
  --col-leaf:      #7FD67F;
  --col-cream:     #FFF8E7;
  --col-ink:       #2F2A24;
  --col-ink-soft:  #6B5E4E;
  --col-rose:      #FF8FA3;
  --col-lavender:  #C8A8FF;
  --col-sun:       #FFE066;
  --col-danger:    #FF4D4D;

  --font-family:   'Fredoka', 'Baloo 2', 'Arial Rounded MT Bold', Arial, sans-serif;
  --font-size-xs:  clamp(12px, 2vmin, 14px);
  --font-size-sm:  clamp(14px, 2.5vmin, 16px);
  --font-size-md:  clamp(16px, 3vmin, 20px);
  --font-size-lg:  clamp(20px, 4vmin, 28px);
  --font-size-xl:  clamp(28px, 6vmin, 48px);
  --font-size-2xl: clamp(40px, 8vmin, 72px);

  --radius:        16px;
  --radius-sm:     10px;
  --radius-pill:   999px;

  --shadow:        0 4px 20px rgba(0,0,0,0.12);
  --shadow-lg:     0 8px 40px rgba(0,0,0,0.18);
  --shadow-card:   0 3px 12px rgba(0,0,0,0.14);

  --transition:    250ms cubic-bezier(0.2, 0.8, 0.2, 1);
  --card-flip-duration: 400ms;
}

/* ─── Reset & base ───────────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
[hidden] { display: none !important; }

html, body {
  height: 100%;
  overflow: hidden;
  font-family: var(--font-family);
  background: var(--col-cream);
  color: var(--col-ink);
  -webkit-font-smoothing: antialiased;
}

body { touch-action: manipulation; }

.skip-link {
  position: absolute; top: -100%; left: 0;
  background: var(--col-primary); color: var(--col-ink);
  padding: 8px 16px; z-index: 1000;
  &:focus { top: 0; }
}

/* Dyslexia font option */
.dyslexia-font { font-family: 'OpenDyslexic', 'Comic Sans MS', cursive !important; }

#app {
  width: 100%; height: 100dvh;
  overflow: hidden;
  position: relative;
  display: flex;
  flex-direction: column;
}

/* ─── Screens ─────────────────────────────────────────────────────────────── */
.screen {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: clamp(12px, 3vmin, 24px);
  background: var(--col-cream);
  overflow-y: auto;
  opacity: 0;
  transform: translateY(12px);
  transition: opacity var(--transition), transform var(--transition);
  pointer-events: none;
}

.screen--visible {
  opacity: 1;
  transform: none;
  pointer-events: auto;
}

/* ─── Typography ─────────────────────────────────────────────────────────── */
.screen-title {
  font-size: var(--font-size-lg);
  font-weight: 700;
  color: var(--col-ink);
  margin-bottom: clamp(8px, 2vmin, 16px);
  text-align: center;
}

.screen-sub {
  font-size: var(--font-size-sm);
  color: var(--col-ink-soft);
  margin-bottom: 12px;
  text-align: center;
}

/* ─── Buttons ─────────────────────────────────────────────────────────────── */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  gap: 8px;
  min-height: 52px; min-width: 120px;
  padding: 12px 24px;
  border: none; border-radius: var(--radius-pill);
  font-family: var(--font-family);
  font-size: var(--font-size-md);
  font-weight: 700;
  cursor: pointer;
  transition: transform var(--transition), box-shadow var(--transition), background var(--transition);
  user-select: none;
  -webkit-tap-highlight-color: transparent;
}

.btn:hover  { transform: translateY(-2px); box-shadow: var(--shadow); }
.btn:active { transform: scale(0.95); }
.btn:focus-visible {
  outline: 4px solid var(--col-primary);
  outline-offset: 3px;
}

.btn--primary   { background: var(--col-primary); color: var(--col-ink); }
.btn--secondary { background: var(--col-sky);     color: #fff; }
.btn--ghost     { background: transparent; color: var(--col-ink); border: 2px solid var(--col-primary); }
.btn--share     { background: var(--col-leaf); color: #fff; }
.btn--danger    { background: var(--col-danger); color: #fff; }
.btn--sm        { min-height: 40px; padding: 8px 16px; font-size: var(--font-size-sm); }
.btn--xl        { min-height: 64px; padding: 16px 36px; font-size: var(--font-size-lg); }
.btn--icon      { min-width: 48px; width: 48px; height: 48px; padding: 0; border-radius: 50%; }

/* ─── Splash screen ──────────────────────────────────────────────────────── */
.screen--splash {
  justify-content: center;
  gap: clamp(12px, 3vmin, 24px);
  background: linear-gradient(160deg, #FFF8E7 0%, #FFE8AA 100%);
}

.splash-logo {
  font-size: clamp(64px, 18vmin, 120px);
  line-height: 1;
  filter: drop-shadow(0 6px 16px rgba(0,0,0,0.15));
}

.splash-title {
  font-size: var(--font-size-2xl);
  font-weight: 700;
  color: var(--col-ink);
  text-shadow: 0 2px 8px rgba(0,0,0,0.08);
}

.splash-sub {
  font-size: var(--font-size-md);
  color: var(--col-ink-soft);
}

.splash-links {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  justify-content: center;
  margin-top: 4px;
}

.splash-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 20px;
  background: rgba(255,255,255,0.75);
  color: var(--col-ink);
  border: 2px solid var(--col-primary);
  border-radius: var(--radius-pill);
  font-family: var(--font-family);
  font-size: var(--font-size-sm);
  font-weight: 700;
  text-decoration: none;
  transition: background var(--transition), transform var(--transition), box-shadow var(--transition);
  backdrop-filter: blur(4px);
}

.splash-link:hover {
  background: var(--col-primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}

.splash-link:active { transform: scale(0.95); }

.splash-link:focus-visible {
  outline: 4px solid var(--col-ink);
  outline-offset: 3px;
}

.splash-link--accent {
  border-color: var(--col-sky);
}

.splash-link--accent:hover {
  background: var(--col-sky);
  color: #fff;
}

/* ─── Age selection ─────────────────────────────────────────────────────── */
.age-grid {
  display: flex;
  flex-wrap: wrap;
  gap: clamp(12px, 2.5vmin, 20px);
  justify-content: center;
  margin-top: 8px;
}

.age-card {
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  gap: 6px;
  min-width: clamp(130px, 28vw, 180px);
  min-height: clamp(130px, 20vh, 180px);
  background: #fff;
  border: 3px solid var(--col-primary);
  border-radius: var(--radius);
  box-shadow: var(--shadow-card);
  cursor: pointer;
  transition: transform var(--transition), box-shadow var(--transition);
  font-family: var(--font-family);
}

.age-card:hover  { transform: translateY(-4px) scale(1.02); box-shadow: var(--shadow); }
.age-card:active { transform: scale(0.96); }
.age-card:focus-visible { outline: 4px solid var(--col-primary); outline-offset: 3px; }

.age-emoji { font-size: clamp(40px, 8vmin, 56px); }
.age-label { font-size: var(--font-size-md); font-weight: 700; color: var(--col-ink); }
.age-range { font-size: var(--font-size-xs); color: var(--col-ink-soft); }

/* ─── Category selection ─────────────────────────────────────────────────── */
.category-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(clamp(110px, 26vw, 160px), 1fr));
  gap: clamp(10px, 2vmin, 16px);
  width: 100%;
  max-width: 600px;
}

.category-card {
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  gap: 8px;
  aspect-ratio: 1;
  background: #fff;
  border: 3px solid var(--cat-accent, var(--col-primary));
  border-radius: var(--radius);
  box-shadow: var(--shadow-card);
  cursor: pointer;
  transition: transform var(--transition), box-shadow var(--transition);
  font-family: var(--font-family);
  position: relative;
  overflow: hidden;
}

.category-card::before {
  content: '';
  position: absolute; inset: 0;
  background: var(--cat-accent, var(--col-primary));
  opacity: 0.08;
}

.category-card:hover  { transform: translateY(-4px) scale(1.03); box-shadow: var(--shadow); }
.category-card:active { transform: scale(0.95); }
.category-card:focus-visible { outline: 4px solid var(--cat-accent, var(--col-primary)); outline-offset: 3px; }

.cat-emoji { font-size: clamp(32px, 7vmin, 52px); }
.cat-label { font-size: var(--font-size-sm); font-weight: 700; color: var(--col-ink); }

/* ─── Difficulty / grid select ───────────────────────────────────────────── */
.diff-grid {
  display: flex;
  flex-wrap: wrap;
  gap: clamp(10px, 2vmin, 16px);
  justify-content: center;
  margin-top: 8px;
}

.diff-btn {
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  gap: 4px;
  min-width: clamp(110px, 26vw, 160px);
  min-height: 80px;
  padding: 14px 20px;
  background: #fff;
  border: 3px solid var(--col-sky);
  border-radius: var(--radius);
  box-shadow: var(--shadow-card);
  cursor: pointer;
  transition: transform var(--transition), box-shadow var(--transition);
  font-family: var(--font-family);
}

.diff-btn:hover  { transform: translateY(-3px); box-shadow: var(--shadow); background: var(--col-sky); color: #fff; }
.diff-btn:active { transform: scale(0.95); }
.diff-btn:focus-visible { outline: 4px solid var(--col-sky); outline-offset: 3px; }
.diff-count { font-size: var(--font-size-md); font-weight: 700; }
.diff-dim   { font-size: var(--font-size-xs); color: var(--col-ink-soft); }
.diff-btn:hover .diff-dim { color: rgba(255,255,255,0.8); }

/* ─── Challenge select ───────────────────────────────────────────────────── */
.challenge-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  width: 100%;
  max-width: 480px;
}

.challenge-opt {
  display: flex; align-items: center; gap: 16px;
  padding: 16px 20px;
  background: #fff;
  border: 3px solid var(--col-primary);
  border-radius: var(--radius);
  box-shadow: var(--shadow-card);
  cursor: pointer;
  text-align: left;
  font-family: var(--font-family);
  transition: transform var(--transition), box-shadow var(--transition);
}

.challenge-opt:hover  { transform: translateX(4px); box-shadow: var(--shadow); }
.challenge-opt:active { transform: scale(0.97); }
.challenge-opt:focus-visible { outline: 4px solid var(--col-primary); outline-offset: 3px; }
.challenge-opt--none  { border-color: var(--col-leaf); }

.chall-icon  { font-size: 32px; flex-shrink: 0; }
.chall-label { font-size: var(--font-size-md); font-weight: 700; color: var(--col-ink); }
.chall-desc  { font-size: var(--font-size-xs); color: var(--col-ink-soft); }

/* ─── Game screen ─────────────────────────────────────────────────────────── */
.screen--game {
  padding: 0;
  justify-content: flex-start;
  background: linear-gradient(160deg, #FFF8E7 0%, #E8F4FF 100%);
  overflow: hidden; /* prevent scroll so game-board flex:1 fills remaining height */
}

/* ─── HUD ─────────────────────────────────────────────────────────────────── */
.hud {
  width: 100%;
  display: flex;
  align-items: center;
  gap: clamp(6px, 1.5vmin, 12px);
  padding: 0 clamp(10px, 2.5vw, 20px);
  background: rgba(255,248,231,0.96);
  backdrop-filter: blur(8px);
  border-bottom: 2px solid var(--col-primary);
  height: 60px;
  flex-shrink: 0;
  z-index: 10;
}

.hud-btn {
  width: 46px; height: 46px;
  border: none; border-radius: 50%;
  background: var(--col-primary);
  font-size: 22px;
  cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  transition: transform var(--transition);
  flex-shrink: 0;
  box-shadow: 0 2px 8px rgba(0,0,0,0.15);
}

.hud-btn:hover  { transform: scale(1.08); }
.hud-btn:active { transform: scale(0.92); }
.hud-btn:focus-visible { outline: 3px solid var(--col-ink); outline-offset: 2px; }

.hud-stats {
  display: flex; gap: clamp(8px, 2vw, 16px);
  flex: 1;
  font-size: clamp(13px, 3.5vw, 16px);
  font-weight: 700;
  color: var(--col-ink);
  white-space: nowrap;
}

.hud-timer {
  font-size: clamp(14px, 3.8vw, 17px);
  font-weight: 800;
  color: var(--col-ink);
  min-width: 44px;
  text-align: center;
  letter-spacing: 0.02em;
}

.challenge-badge {
  display: inline-flex; align-items: center;
  padding: 4px 12px;
  background: var(--col-sky);
  color: #fff;
  border-radius: var(--radius-pill);
  font-size: var(--font-size-xs);
  font-weight: 700;
  white-space: nowrap;
}

.challenge-badge--warning { background: var(--col-primary); color: var(--col-ink); }
.challenge-badge--danger  { background: var(--col-danger); }

/* ─── Game board wrapper ─────────────────────────────────────────────────── */
.game-board {
  flex: 1;
  min-height: 0;
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: clamp(8px, 2vmin, 16px);
  overflow: hidden;
}

/* ─── Card Grid ──────────────────────────────────────────────────────────── */
.card-grid {
  display: grid;
  /* Default: use cols from config */
  grid-template-columns: repeat(var(--cols), 1fr);
  gap: clamp(6px, 1.4vmin, 14px);
  /*
   * Size: fill the board as much as possible.
   * --avail-h = 100dvh minus HUD (60px) minus board padding (2×14px)
   * --avail-w = 100vw minus board padding (2×14px)
   * Width = min(avail-w, avail-h × cols/rows)
   * Then aspect-ratio keeps height proportional.
   */
  --_pad: clamp(8px, 2vmin, 16px);
  --_avail-h: calc(100dvh - 60px - var(--_pad) * 2);
  --_avail-w: calc(100vw  - var(--_pad) * 2);
  width: min(var(--_avail-w), calc(var(--_avail-h) * var(--cols) / var(--rows)));
  aspect-ratio: var(--cols) / var(--rows);
}

/* Portrait: reflow wide grids (more cols than rows) into a taller layout */
@media (orientation: portrait) {
  .card-grid {
    grid-template-columns: repeat(var(--portrait-cols, var(--cols)), 1fr);
    width: min(
      var(--_avail-w),
      calc(var(--_avail-h) * var(--portrait-cols, var(--cols)) / var(--portrait-rows, var(--rows)))
    );
    aspect-ratio: var(--portrait-cols, var(--cols)) / var(--portrait-rows, var(--rows));
  }
}

/* Landscape phone: tight layout */
@media (orientation: landscape) and (max-height: 500px) {
  .hud { height: 48px; }
  .hud-btn { width: 38px; height: 38px; font-size: 18px; }
  .game-board { padding: 4px 6px; }
  .card-grid {
    --_avail-h: calc(100dvh - 48px - 10px);
    --_avail-w: calc(100vw - 12px);
    gap: clamp(3px, 0.8vmin, 8px);
  }
}

/* ─── Card ────────────────────────────────────────────────────────────────── */
.card {
  position: relative;
  perspective: 600px;
  background: transparent;
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  padding: 0;
  min-width: 0;
  aspect-ratio: 1;
  -webkit-tap-highlight-color: transparent;
}

.card:focus-visible .card-inner {
  outline: 4px solid var(--col-primary);
  outline-offset: 2px;
  border-radius: var(--radius);
}

.card--matched { cursor: default; pointer-events: none; }

.card-inner {
  position: relative;
  width: 100%; height: 100%;
  transform-style: preserve-3d;
  transition: transform var(--card-flip-duration) cubic-bezier(0.4, 0, 0.2, 1);
  border-radius: var(--radius);
}

.card--flipped .card-inner,
.card--matched .card-inner {
  transform: rotateY(180deg);
}

.card-face {
  position: absolute; inset: 0;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  border-radius: var(--radius);
  display: flex; align-items: center; justify-content: center;
  overflow: hidden;
}

.card-face--back {
  background: linear-gradient(135deg, var(--col-primary) 0%, #FF8C00 100%);
  box-shadow: var(--shadow-card);
  font-size: clamp(20px, 5vmin, 40px);
  border: 3px solid rgba(255,255,255,0.4);
}

/* Subtle pattern on card back */
.card-face--back::after {
  content: '';
  position: absolute; inset: 0;
  background: repeating-linear-gradient(
    45deg,
    rgba(255,255,255,0.07) 0px, rgba(255,255,255,0.07) 4px,
    transparent 4px, transparent 12px
  );
}

.card-face--front {
  background: #fff;
  transform: rotateY(180deg);
  border: 3px solid var(--col-primary);
  box-shadow: var(--shadow-card);
}

.card-face--front img {
  width: 80%; height: 80%;
  object-fit: contain;
  border-radius: var(--radius-sm);
  pointer-events: none;
}

.card--matched .card-face--front {
  border-color: var(--col-leaf);
  background: #F0FFF4;
}

/* ─── Celebrate screen ───────────────────────────────────────────────────── */
.screen--celebrate {
  justify-content: center;
  gap: clamp(10px, 2.5vmin, 20px);
  background: linear-gradient(160deg, #FFF8E7 0%, #E8FFE8 100%);
}

.celebrate-emoji {
  font-size: clamp(64px, 16vmin, 100px);
  line-height: 1;
}

.celebrate-title {
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--col-ink);
}

.star-row {
  display: flex; gap: 8px;
}

.star {
  font-size: clamp(28px, 6vmin, 44px);
  display: inline-block;
}

.star--earned { filter: drop-shadow(0 2px 6px rgba(255,184,77,0.7)); }
.star--empty  { opacity: 0.3; }

.celebrate-stats {
  display: flex; gap: 16px;
  font-size: var(--font-size-sm);
  color: var(--col-ink-soft);
}

.celebrate-stats strong { color: var(--col-ink); }

.foil-badge {
  padding: 8px 20px;
  background: linear-gradient(90deg, #FFD700, #FFF, #C0C0C0, #FFD700);
  background-size: 200% 100%;
  border-radius: var(--radius-pill);
  font-weight: 700;
  font-size: var(--font-size-sm);
  color: var(--col-ink);
  box-shadow: var(--shadow);
}

.celebrate-btns {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
}

/* ─── Sticker album ──────────────────────────────────────────────────────── */
.screen--stickers { overflow-y: auto; align-items: flex-start; }

.sticker-album {
  width: 100%;
  max-width: 600px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.sticker-section {}
.sticker-cat-title {
  font-size: var(--font-size-md);
  font-weight: 700;
  color: var(--col-ink);
  margin-bottom: 8px;
}

.sticker-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 6px;
}

.sticker-row-label {
  font-size: var(--font-size-xs);
  color: var(--col-ink-soft);
  margin-bottom: 4px;
}

.sticker-item {
  width: clamp(44px, 9vmin, 60px);
  height: clamp(44px, 9vmin, 60px);
  border-radius: var(--radius-sm);
  display: flex; align-items: center; justify-content: center;
  font-size: clamp(20px, 4.5vmin, 30px);
  border: 2px solid transparent;
  transition: transform var(--transition);
}

.sticker-item--owned {
  background: #fff;
  border-color: var(--col-leaf);
  box-shadow: var(--shadow-card);
}

.sticker-item--owned:hover { transform: scale(1.12); }

.sticker-item--locked {
  background: #E0D8CC;
  color: #B0A898;
  border-color: #C8C0B4;
}

.sticker-item--streak {
  border-color: var(--col-danger);
}

/* ─── Settings screen ────────────────────────────────────────────────────── */
.screen--settings { overflow-y: auto; }

.settings-list {
  width: 100%;
  max-width: 480px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.setting-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 12px 16px;
  background: #fff;
  border-radius: var(--radius);
  box-shadow: var(--shadow-card);
  cursor: pointer;
  font-size: var(--font-size-sm);
  font-weight: 600;
}

.setting-row input[type="range"] { flex: 1; max-width: 140px; accent-color: var(--col-primary); }
.setting-row input[type="checkbox"] { width: 24px; height: 24px; accent-color: var(--col-primary); cursor: pointer; }

/* ─── Nav bar ─────────────────────────────────────────────────────────────── */
.nav-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 100%;
  max-width: 600px;
  margin-top: auto;
  padding-top: 12px;
}

/* ─── Modals ──────────────────────────────────────────────────────────────── */
.modal-overlay {
  position: fixed; inset: 0;
  background: rgba(47,42,36,0.55);
  display: flex; align-items: center; justify-content: center;
  z-index: 100;
  backdrop-filter: blur(4px);
}

.modal-box {
  background: var(--col-cream);
  border-radius: var(--radius);
  padding: clamp(20px, 4vmin, 36px);
  max-width: 360px; width: 90%;
  box-shadow: var(--shadow-lg);
  text-align: center;
  display: flex; flex-direction: column;
  align-items: center; gap: 16px;
}

.modal-emoji { font-size: 56px; }
.modal-msg { font-size: var(--font-size-md); color: var(--col-ink); line-height: 1.4; }
.modal-btns { display: flex; gap: 12px; flex-wrap: wrap; justify-content: center; }

/* ─── Toast ───────────────────────────────────────────────────────────────── */
#toast-container {
  position: fixed;
  bottom: 24px; left: 50%; transform: translateX(-50%);
  display: flex; flex-direction: column; align-items: center;
  gap: 8px; z-index: 200;
  pointer-events: none;
}

.toast {
  padding: 10px 20px;
  background: var(--col-ink);
  color: #fff;
  border-radius: var(--radius-pill);
  font-size: var(--font-size-sm);
  font-weight: 600;
  box-shadow: var(--shadow);
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 0.25s, transform 0.25s;
}

.toast--visible { opacity: 1; transform: none; }

.sticker-toast {
  padding: 10px 20px;
  background: var(--col-leaf);
  color: #fff;
  border-radius: var(--radius-pill);
  font-size: var(--font-size-sm);
  font-weight: 700;
  box-shadow: var(--shadow);
}

.sticker-toast--foil {
  background: linear-gradient(90deg, #FFD700, #FFF, #C0C0C0);
  color: var(--col-ink);
}

/* ─── Responsive ──────────────────────────────────────────────────────────── */
@media (max-width: 480px) {
  .age-card { min-width: 120px; min-height: 120px; }
  .hud-stats { gap: 8px; font-size: 12px; }
  .celebrate-btns .btn { padding: 10px 16px; font-size: 14px; }
}

@media (max-height: 600px) {
  .screen { padding: 8px; }
  .screen-title { font-size: 18px; margin-bottom: 6px; }
  .nav-bar { padding-top: 6px; }
}