:root {
  --bg: #0f172a;
  --bg-2: #1e293b;
  --bg-3: #334155;
  --fg: #f1f5f9;
  --fg-2: #cbd5e1;
  --fg-3: #94a3b8;
  --pri: #38bdf8;
  --pri-2: #0ea5e9;
  --ok: #22c55e;
  --bad: #ef4444;
  --warn: #f59e0b;
  --card: #1e293b;
  --br: 14px;
  --safe-b: env(safe-area-inset-bottom, 0);
  --safe-t: env(safe-area-inset-top, 0);
}
@media (prefers-color-scheme: light) {
  :root {
    --bg: #f8fafc;
    --bg-2: #ffffff;
    --bg-3: #e2e8f0;
    --fg: #0f172a;
    --fg-2: #334155;
    --fg-3: #64748b;
    --card: #ffffff;
  }
}

* { box-sizing: border-box; -webkit-tap-highlight-color: transparent; }
html, body { margin: 0; padding: 0; height: 100%; overscroll-behavior-y: contain; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang TC", "Microsoft JhengHei", sans-serif;
  background: var(--bg); color: var(--fg);
  padding: var(--safe-t) 0 var(--safe-b); font-size: 16px;
}
#app { max-width: 640px; margin: 0 auto; padding: 12px 16px 32px; }

button { font-family: inherit; font-size: inherit; }
h1, h2, h3 { margin: 0; }

/* ── 首頁 ── */
.hero { display: grid; gap: 14px; padding: 8px 0 4px; }
.hero-top { display: flex; align-items: center; justify-content: space-between; }
.hero-top h1 { font-size: 24px; font-weight: 800; letter-spacing: .5px; }
.stats-row { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; }
.stat { background: var(--card); padding: 10px; border-radius: var(--br); text-align: center; }
.stat .v { font-size: 22px; font-weight: 800; color: var(--pri); }
.stat .k { font-size: 12px; color: var(--fg-3); margin-top: 2px; }

.daily-card {
  background: linear-gradient(135deg, var(--pri-2), #a855f7);
  padding: 14px 16px; border-radius: var(--br);
  display: flex; align-items: center; justify-content: space-between; gap: 12px;
  color: #fff;
}
.daily-title { font-weight: 700; }
.daily-sub { font-size: 13px; opacity: .9; margin-top: 2px; }

.modes { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin: 18px 0 12px; }
.mode-card {
  background: var(--card); color: var(--fg); border: 0;
  padding: 18px 12px; border-radius: var(--br);
  display: grid; gap: 6px; text-align: left; cursor: pointer;
  transition: transform .1s ease;
  min-height: 110px;
}
.mode-card:active { transform: scale(.97); }
.mode-emoji { font-size: 28px; }
.mode-name { font-weight: 700; font-size: 16px; }
.mode-desc { font-size: 12px; color: var(--fg-3); }

.side-actions { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; margin-top: 8px; }

.foot { text-align: center; color: var(--fg-3); font-size: 11px; margin-top: 24px; }

/* ── 通用按鈕 ── */
.btn {
  border: 0; border-radius: 10px; padding: 12px 16px;
  font-weight: 700; cursor: pointer; background: var(--bg-3); color: var(--fg);
  min-height: 44px;
}
.btn.primary { background: var(--pri); color: #001018; }
.btn.ghost { background: transparent; border: 1px solid var(--bg-3); }
.btn.danger { background: var(--bad); color: #fff; }
.btn.small { padding: 8px 12px; font-size: 14px; min-height: 40px; }
.btn:active { opacity: .85; }
.icon-btn {
  background: transparent; border: 0; color: var(--fg);
  width: 40px; height: 40px; border-radius: 10px;
  display: grid; place-items: center; font-size: 20px;
}
.icon-btn:active { background: var(--bg-3); }

/* ── 頁面頭 ── */
.page-head {
  display: flex; align-items: center; gap: 10px; margin-bottom: 12px;
}
.page-head h2 { flex: 1; text-align: center; font-size: 18px; }
.progress-bar {
  flex: 1; height: 8px; background: var(--bg-3); border-radius: 999px; overflow: hidden;
}
.progress-fill { height: 100%; width: 0%; background: var(--pri); transition: width .3s; }
.timer-bar { height: 4px; background: var(--bg-3); border-radius: 999px; overflow: hidden; margin: 4px 0 14px; }
.timer-fill { height: 100%; width: 100%; background: var(--warn); transition: width .1s linear; }
.score-chip {
  background: var(--card); padding: 6px 10px; border-radius: 10px;
  font-weight: 700; font-size: 14px; white-space: nowrap;
}

/* ── 遊戲共用 ── */
.game-body { padding: 8px 0; display: grid; gap: 14px; }
.direction-tag {
  align-self: start; padding: 4px 10px; background: var(--bg-3);
  border-radius: 999px; font-size: 12px; color: var(--fg-2); width: fit-content;
}
.prompt-word {
  font-size: 34px; font-weight: 800; text-align: center;
  padding: 24px 8px; background: var(--card); border-radius: var(--br);
  line-height: 1.3; word-break: break-word;
}
.tts-btn {
  align-self: center; background: var(--bg-3); border: 0; color: var(--fg);
  width: 56px; height: 56px; border-radius: 50%;
  font-size: 24px; cursor: pointer;
}
.tts-btn:active { background: var(--pri); }

.options { display: grid; gap: 10px; }
.option {
  background: var(--card); border: 2px solid transparent; color: var(--fg);
  padding: 16px; border-radius: var(--br); text-align: left;
  cursor: pointer; font-size: 16px; min-height: 56px;
  transition: all .2s;
}
.option:active { transform: scale(.98); }
.option.correct { border-color: var(--ok); background: rgba(34,197,94,.15); }
.option.wrong { border-color: var(--bad); background: rgba(239,68,68,.15); }
.option[disabled] { cursor: default; }

/* ── 拼字 ── */
.spell-slots {
  display: flex; flex-wrap: wrap; gap: 6px; justify-content: center;
  padding: 12px; background: var(--card); border-radius: var(--br); min-height: 60px;
}
.slot {
  width: 32px; height: 40px; border-bottom: 3px solid var(--fg-3);
  display: grid; place-items: center; font-size: 22px; font-weight: 700;
  text-transform: lowercase;
}
.slot.filled { border-color: var(--pri); }
.slot.locked { color: var(--fg-3); border-color: var(--bg-3); }
.slot.space { border: 0; width: 12px; }
.spell-actions { display: grid; grid-template-columns: 1fr 1fr 1.4fr; gap: 8px; }
.keyboard {
  display: grid; grid-template-columns: repeat(10, 1fr); gap: 4px;
  padding: 4px 0;
}
.key {
  background: var(--card); border: 0; color: var(--fg);
  padding: 12px 0; border-radius: 8px; font-weight: 700; font-size: 14px;
  text-transform: uppercase; min-height: 42px;
}
.key:active { background: var(--pri); color: #001018; }
.key[disabled] { opacity: .3; }

/* ── 翻卡 ── */
.card-flip {
  position: relative; height: 260px; perspective: 1000px; cursor: pointer;
}
.card-face {
  position: absolute; inset: 0;
  background: var(--card); border-radius: var(--br);
  padding: 20px; display: grid; place-items: center; gap: 12px;
  backface-visibility: hidden;
  transition: transform .5s;
}
.card-front { transform: rotateY(0deg); }
.card-back { transform: rotateY(180deg); }
.card-flip.flipped .card-front { transform: rotateY(-180deg); }
.card-flip.flipped .card-back { transform: rotateY(0deg); }
.card-face .hint { color: var(--fg-3); font-size: 12px; }
.zh-list { color: var(--fg-2); font-size: 18px; text-align: center; }
.tag-row { display: flex; gap: 6px; }
.tag {
  background: var(--bg-3); padding: 3px 10px; border-radius: 999px;
  font-size: 11px; color: var(--fg-2);
}
.srs-buttons { display: grid; grid-template-columns: repeat(4, 1fr); gap: 6px; }
.srs-btn {
  border: 0; border-radius: 10px; padding: 12px 4px; font-weight: 700;
  font-size: 13px; color: #fff; min-height: 56px;
}
.srs-btn.again { background: #ef4444; }
.srs-btn.hard  { background: #f59e0b; }
.srs-btn.good  { background: #22c55e; }
.srs-btn.easy  { background: #38bdf8; color: #001018; }
.srs-btn:active { opacity: .8; }
.srs-buttons.hidden { visibility: hidden; }

/* ── 聽力 ── */
.listen-orb {
  justify-self: center; width: 140px; height: 140px; border-radius: 50%;
  background: radial-gradient(circle at 30% 30%, var(--pri), var(--pri-2));
  border: 0; color: #001018; font-size: 56px; cursor: pointer;
  box-shadow: 0 8px 24px rgba(56,189,248,.35);
  animation: pulse 2.5s ease-in-out infinite;
}
.listen-orb:active { transform: scale(.95); }
@keyframes pulse {
  0%,100% { box-shadow: 0 8px 24px rgba(56,189,248,.35); }
  50%     { box-shadow: 0 12px 34px rgba(56,189,248,.55); }
}

/* ── 結算 ── */
.result { text-align: center; padding: 12px 0; }
.result-score { font-size: 72px; font-weight: 900; color: var(--pri); }
.result-sub { color: var(--fg-3); margin-bottom: 20px; }
.result-actions { display: grid; gap: 10px; margin-bottom: 24px; }
.wrong-list { list-style: none; padding: 0; margin: 8px 0; display: grid; gap: 8px; }
.wrong-list li {
  background: var(--card); padding: 12px 14px; border-radius: 10px;
  display: flex; justify-content: space-between; gap: 8px; align-items: center;
}
.wrong-list .w-en { font-weight: 700; }
.wrong-list .w-zh { color: var(--fg-3); font-size: 14px; text-align: right; }

/* ── 設定 ── */
.form { display: grid; gap: 12px; padding: 8px 0; }
.form .row {
  display: flex; align-items: center; justify-content: space-between; gap: 12px;
  background: var(--card); padding: 12px 14px; border-radius: var(--br);
}
.form .row select, .form .row input {
  background: var(--bg); color: var(--fg);
  border: 1px solid var(--bg-3); padding: 8px 10px; border-radius: 8px;
  font-size: 15px; min-height: 40px;
}
.form .btn.danger { margin-top: 12px; }

.wb-actions { margin: 8px 0 14px; }

/* ── 動畫 ── */
.shake { animation: shake .3s; }
@keyframes shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-6px); }
  75% { transform: translateX(6px); }
}
.pop { animation: pop .3s; }
@keyframes pop {
  0% { transform: scale(1); }
  50% { transform: scale(1.06); }
  100% { transform: scale(1); }
}