:root {
  --bg: #fff8f3;
  --card: #ffffff;
  --text: #333;
  --accent: #ff7aa2;
  --accent-2: #6ecb63;
  --accent-3: #6ec5ff;
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  font-family: ui-rounded, system-ui, -apple-system, Segoe UI, Roboto, "PingFang SC", "Microsoft Yahei", sans-serif;
  background: linear-gradient(180deg, #fff6ee, #f7fbff);
  color: var(--text);
  display: flex;
  flex-direction: column;
}

.app-header {
  padding: 16px 20px;
  background: radial-gradient(1200px 200px at 50% -50px, #ffe7f0, transparent),
              radial-gradient(900px 200px at 10% -60px, #e6fbff, transparent);
  border-bottom: 1px solid #eee;
}
.app-header h1 { margin: 0 0 8px; font-size: 24px; }
.mode-switch { display: flex; gap: 8px; flex-wrap: wrap; }
.tab-btn {
  border: 2px solid transparent;
  background: var(--card);
  padding: 8px 12px;
  border-radius: 999px;
  cursor: pointer;
  font-weight: 600;
  color: #333; /* ensure text visible on light background */
  touch-action: manipulation;
}
.tab-btn.active { border-color: var(--accent); color: #c2185b; }

main { padding: 20px; display: grid; place-items: start center; }
.tab { display: none; width: min(900px, 96vw); }
.tab.active { display: block; }

.card {
  background: var(--card);
  box-shadow: 0 10px 30px rgba(0,0,0,0.06);
  border-radius: 16px;
  padding: 20px;
}

.big-letter {
  font-size: clamp(40px, 12vw, 140px);
  text-align: center;
  letter-spacing: 8px;
  margin: 8px 0 4px;
  color: #222;
}
.word { text-align: center; font-size: clamp(18px, 3.6vw, 32px); color: #444; }

.controls { display: flex; gap: 8px; justify-content: center; margin-top: 12px; }
button {
  padding: 10px 14px;
  border: none;
  background: var(--accent);
  color: white;
  border-radius: 10px;
  cursor: pointer;
  font-size: 16px;
}
button.secondary { background: #e9eef3; color: #333; }
button:disabled { opacity: .5; cursor: not-allowed; }

.tiny { display: flex; justify-content: center; margin-top: 8px; font-size: 12px; color: #666; }

.quiz-header { display: flex; gap: 10px; align-items: center; justify-content: space-between; flex-wrap: wrap; }
.prompt { font-size: clamp(18px, 3.2vw, 28px); font-weight: 700; }
.choices { margin-top: 14px; display: grid; grid-template-columns: repeat(2, minmax(120px, 1fr)); gap: 10px; }
.choice {
  display: grid; place-items: center;
  height: 80px;
  font-size: 36px;
  background: #fff;
  border: 2px solid #dfe6ee;
  border-radius: 12px;
  transition: transform .06s ease, border-color .2s ease;
  /* Override global button color (white) so letters are visible */
  color: #222;
  font-weight: 800;
}
.choice:hover { transform: translateY(-1px); }
.choice.correct { border-color: var(--accent-2); background: #f1fff4; }
.choice.wrong { border-color: #ffb3b3; background: #fff1f1; animation: shake .2s; }
@keyframes shake { 25%{transform:translateX(-2px)} 75%{transform:translateX(2px)} }

.status { margin-top: 10px; display: flex; gap: 20px; color: #555; }

.match-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-top: 8px; }
.col h3 { margin: 6px 0; }
.bucket { display: grid; gap: 8px; grid-template-columns: repeat(3, 1fr); }
.tile {
  display: grid; place-items: center;
  background: #fff;
  border: 2px dashed #cfd8dc;
  border-radius: 10px;
  height: 72px; font-size: 36px; user-select: none;
  touch-action: manipulation;
}
.tile.dragging { opacity: .6; }
.tile.selected { border-style: solid; border-color: var(--accent-3); background: #eef7ff; }
.drop { border-style: solid; }
.drop.ok { border-color: var(--accent-2); background: #f1fff4; }
.drop.no { border-color: #ffb3b3; background: #fff1f1; }
.done { opacity: .7; background: #f7fff9; border-color: var(--accent-2); }

#celebrate { position: fixed; inset: 0; pointer-events: none; overflow: hidden; }
.confetti { position: absolute; font-size: 24px; animation: fall 800ms ease-out forwards; }
@keyframes fall { to { transform: translateY(100vh) rotate(420deg); opacity: 0; } }

.app-footer { text-align: center; color: #777; font-size: 13px; padding: 16px; }

@media (max-width: 480px) {
  .choices { grid-template-columns: repeat(2, 1fr); }
  .bucket { grid-template-columns: repeat(2, 1fr); }
}

/* A–Z Grid game */
.order-header { display: flex; gap: 10px; align-items: center; justify-content: space-between; flex-wrap: wrap; }
.order-actions { display: flex; gap: 8px; align-items: center; }
.az-grid { margin-top: 12px; display: grid; grid-template-columns: repeat(6, minmax(48px, 1fr)); gap: 8px; }
.tile.az {
  display: grid; place-items: center;
  height: 64px; font-size: 28px; font-weight: 800; color: #222;
  background: #fff;
  border: 2px solid #dfe6ee; border-radius: 10px;
  cursor: pointer; user-select: none;
  transition: transform .06s ease, border-color .2s ease, background .2s ease;
  touch-action: manipulation;
}
.tile.az:hover { transform: translateY(-1px); }
.tile.az.done { background: #f1fff4; border-color: var(--accent-2); opacity: .9; }
.tile.az.wrong { background: #fff1f1; border-color: #ffb3b3; animation: shake .2s; }

@media (max-width: 600px) {
  .az-grid { grid-template-columns: repeat(4, minmax(48px, 1fr)); }
}

/* segmented toggle */
.seg { display: inline-flex; background: #f0f3f6; padding: 4px; border-radius: 999px; }
.seg-btn { background: transparent; color: #333; padding: 6px 10px; border-radius: 999px; border: none; cursor: pointer; font-weight: 600; }
.seg-btn.active { background: #fff; color: #111; box-shadow: 0 1px 3px rgba(0,0,0,.08); }

/* touch feedback */
.pressing { transform: scale(0.98); }