/* 6 岁友好：暖色 + 可爱化 + 动画 */
:root {
  --bg: #fff8ec;
  --bg2: #fff1d6;
  --card: #ffffff;
  --primary: #ff8a3d;
  --primary-dark: #e8731f;
  --pink: #ff8aa6;
  --mint: #7ed8b8;
  --ok: #4cb963;
  --fuzzy: #f5b942;
  --no: #ef5350;
  --text: #4a3b2a;
  --muted: #9a8b7a;
  --border: #f3e2c5;
  --shadow: 0 3px 8px rgba(255, 138, 61, 0.14), 0 1px 3px rgba(0,0,0,0.06);
  --shadow-lg: 0 5px 14px rgba(255, 138, 61, 0.20), 0 2px 6px rgba(0,0,0,0.08);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: linear-gradient(180deg, var(--bg) 0%, var(--bg2) 100%);
  color: var(--text);
  font-family: "STKaiti", "KaiTi", "Microsoft YaHei", "PingFang SC", sans-serif;
  font-size: 18px;
  min-height: 100vh;
  overflow-x: hidden;
}

/* ---- 背景飘动装饰 ---- */
.bg-decor {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  overflow: hidden;
}
.bg-decor span {
  position: absolute;
  bottom: -40px;
  left: var(--x);
  font-size: 26px;
  opacity: 0.5;
  will-change: transform;
  animation: floatUp var(--t) linear infinite;
  animation-delay: var(--d);
}
@keyframes floatUp {
  0%   { transform: translate3d(0, 0, 0); opacity: 0; }
  10%  { opacity: 0.5; }
  90%  { opacity: 0.5; }
  100% { transform: translate3d(0, -110vh, 0); opacity: 0; }
}
/* 用户系统设置了"减少动画"则关闭背景飘动 */
@media (prefers-reduced-motion: reduce) {
  .bg-decor { display: none; }
  *, *::before, *::after { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
}

/* ---- topbar ---- */
.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 14px 24px;
  background: #fffaf0;
  border-bottom: 3px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 10;
}
.logo {
  margin: 0;
  font-size: 26px;
  cursor: pointer;
  user-select: none;
}
.nav { display: flex; gap: 8px; align-items: center; }
.nav button {
  background: transparent;
  border: 2px solid var(--border);
  border-radius: 14px;
  padding: 8px 16px;
  font-size: 16px;
  cursor: pointer;
  color: var(--text);
  font-family: inherit;
  transition: transform .12s, background .15s;
}
.nav button:hover { background: var(--bg); transform: translateY(-1px); }
.sound-toggle { font-size: 18px; padding: 6px 10px !important; }

main {
  max-width: 960px;
  margin: 0 auto;
  padding: 24px 16px 80px;
  position: relative;
  z-index: 1;
}

.view { animation: fade .25s ease; }
@keyframes fade { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }

h2 { font-size: 30px; margin: 0 0 8px; }
h3 { font-size: 22px; margin: 0 0 12px; }
.hint { color: var(--muted); margin: 4px 0 16px; }
.hint.small { font-size: 14px; }

/* ---- 主页 hero ---- */
.home-hero {
  display: flex;
  align-items: flex-end;
  gap: 16px;
  margin: 8px 0 24px;
  min-height: 200px;
}
.home-mascot { width: 200px; height: 220px; flex-shrink: 0; }
.speech-bubble {
  position: relative;
  background: #fff;
  border: 2px solid var(--border);
  border-radius: 20px;
  padding: 14px 20px;
  font-size: 20px;
  font-weight: 600;
  color: var(--text);
  box-shadow: var(--shadow);
  margin-bottom: 50px;
}
.speech-bubble::before {
  content: '';
  position: absolute;
  left: -12px;
  bottom: 18px;
  width: 0; height: 0;
  border: 12px solid transparent;
  border-right-color: var(--border);
}
.speech-bubble::after {
  content: '';
  position: absolute;
  left: -8px;
  bottom: 20px;
  width: 0; height: 0;
  border: 10px solid transparent;
  border-right-color: #fff;
}
@keyframes bobble {
  0%, 100% { transform: translateY(0); }
  50%      { transform: translateY(-4px); }
}

/* ---- 主页大按钮 ---- */
.big-buttons {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-top: 16px;
  max-width: 480px;
}
.big-btn {
  min-height: 68px;
  padding: 16px 24px;
  font-size: 22px;
  font-weight: 600;
  border: 3px solid var(--border);
  border-radius: 20px;
  background: var(--card);
  color: var(--text);
  cursor: pointer;
  font-family: inherit;
  box-shadow: var(--shadow);
  transition: transform .12s ease, background .15s ease, box-shadow .15s ease;
}
.big-btn:hover { background: #fffaf0; transform: translateY(-2px) rotate(-0.5deg); box-shadow: var(--shadow-lg); }
.big-btn:active { transform: translateY(1px) scale(0.98); }
.big-btn.primary {
  background: linear-gradient(180deg, #ffa05c 0%, var(--primary) 100%);
  color: #fff;
  border-color: var(--primary-dark);
  box-shadow: 0 6px 0 var(--primary-dark), 0 8px 16px rgba(255, 138, 61, 0.3);
}
.big-btn.primary:hover { background: linear-gradient(180deg, #ffae6e 0%, var(--primary-dark) 100%); }
.big-btn.primary:active { box-shadow: 0 2px 0 var(--primary-dark), 0 4px 8px rgba(255, 138, 61, 0.3); transform: translateY(4px); }

/* ---- 设置页 ---- */
.group {
  background: var(--card);
  border: 3px solid var(--border);
  border-radius: 22px;
  padding: 18px 22px;
  margin-bottom: 18px;
  box-shadow: var(--shadow);
}
.group-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
}
.link-btn {
  background: transparent;
  border: none;
  color: var(--primary-dark);
  cursor: pointer;
  font-size: 14px;
  margin-left: 8px;
  text-decoration: underline;
  font-family: inherit;
}
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(72px, 1fr));
  gap: 8px;
}
.cell {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 12px 4px;
  border: 2px solid var(--border);
  border-radius: 14px;
  cursor: pointer;
  user-select: none;
  font-size: 18px;
  font-weight: 600;
  background: #fcf6e9;
  transition: background .12s, border-color .12s, transform .1s;
}
.cell:hover { transform: scale(1.05); }
.cell.checked {
  background: linear-gradient(180deg, #ffa05c, var(--primary));
  color: #fff;
  border-color: var(--primary-dark);
  box-shadow: 0 3px 0 var(--primary-dark);
}
#qps {
  font-size: 18px;
  padding: 10px 14px;
  width: 110px;
  border: 2px solid var(--border);
  border-radius: 12px;
  font-family: inherit;
}

.actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 16px;
}

/* ---- 练习页 ---- */
.view-practice { text-align: center; }
.practice-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: 600px;
  margin: 0 auto 16px;
}
.star-progress {
  display: flex;
  gap: 4px;
  font-size: 28px;
  line-height: 1;
}
.star-progress .lit { filter: none; }
.star-progress .dim { opacity: 0.25; filter: grayscale(0.6); }

.streak-badge {
  font-size: 18px;
  font-weight: 700;
  color: var(--primary-dark);
  min-height: 32px;
  display: flex;
  align-items: center;
  gap: 6px;
}
.streak-badge.show { animation: popIn .4s ease; }
@keyframes popIn {
  0%   { transform: scale(0.6); opacity: 0; }
  70%  { transform: scale(1.15); opacity: 1; }
  100% { transform: scale(1); opacity: 1; }
}

.card {
  position: relative;
  background:
    radial-gradient(circle at 20% 20%, rgba(255, 184, 138, 0.15) 0, transparent 30%),
    radial-gradient(circle at 80% 80%, rgba(255, 138, 166, 0.12) 0, transparent 30%),
    var(--card);
  border: 4px solid var(--border);
  border-radius: 28px;
  padding: 60px 24px;
  margin: 0 auto;
  max-width: 600px;
  box-shadow: var(--shadow-lg);
  transition: transform .3s ease;
}
.card.flash {
  animation: cardFlash .5s ease;
}
@keyframes cardFlash {
  0%   { box-shadow: var(--shadow-lg); transform: scale(1); }
  30%  { box-shadow: 0 0 0 8px rgba(255, 211, 138, 0.7), var(--shadow-lg); transform: scale(1.03); }
  100% { box-shadow: var(--shadow-lg); transform: scale(1); }
}

.pinyin-display {
  font-size: 160px;
  font-weight: 700;
  letter-spacing: 6px;
  line-height: 1.1;
  color: #2d2418;
  font-family: "Microsoft YaHei", "PingFang SC", sans-serif;
  text-shadow: 3px 3px 0 rgba(255, 138, 61, 0.18);
  animation: popIn .35s ease;
}

.speak-btn {
  position: absolute;
  right: 20px;
  bottom: 20px;
  width: 56px;
  height: 56px;
  border-radius: 50%;
  border: 2px solid var(--border);
  background: #fcf6e9;
  font-size: 24px;
  cursor: pointer;
  transition: transform .12s, background .15s;
}
.speak-btn:hover { background: var(--bg); transform: scale(1.08); }

.judge-row {
  display: flex;
  justify-content: center;
  gap: 16px;
  margin: 32px auto 16px;
  flex-wrap: wrap;
  max-width: 720px;
}
.judge-btn {
  flex: 1 1 180px;
  max-width: 240px;
  min-height: 84px;
  font-size: 24px;
  font-weight: 700;
  border: 3px solid;
  border-radius: 22px;
  cursor: pointer;
  color: #fff;
  font-family: inherit;
  box-shadow: var(--shadow);
  transition: transform .1s ease, filter .15s ease;
}
.judge-btn:active { transform: scale(0.95); }
.judge-btn.ok    { background: linear-gradient(180deg, #5cd17a, var(--ok));    border-color: #3a9a4f; box-shadow: 0 5px 0 #3a9a4f, 0 6px 14px rgba(76,185,99,0.3); }
.judge-btn.fuzzy { background: linear-gradient(180deg, #ffce5e, var(--fuzzy)); border-color: #d6a032; color: #4a3b2a; box-shadow: 0 5px 0 #d6a032, 0 6px 14px rgba(245,185,66,0.3); }
.judge-btn.no    { background: linear-gradient(180deg, #ff7574, var(--no));    border-color: #c83b39; box-shadow: 0 5px 0 #c83b39, 0 6px 14px rgba(239,83,80,0.3); }
.judge-btn:hover { filter: brightness(1.07); transform: translateY(-2px); }

/* 练习页 mascot 在右下角 */
.practice-bottom {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  margin-top: 24px;
  max-width: 720px;
  margin-left: auto;
  margin-right: auto;
}
.practice-mascot { width: 140px; height: 154px; }

/* ---- mascot 通用样式 ---- */
.mascot { display: inline-block; position: relative; }
.mascot-svg { width: 100%; height: 100%; }
/* 不再持续 breathe，避免每帧重绘整个 SVG。需要"活泼感"时才在 .happy/.cheer 上做一次性动画 */

/* 默认 mood-idle：圆睁眼睛、不笑、手垂下、无星星无牌子 */
.mascot .m-eyes-open    { display: block; }
.mascot .m-eyes-happy   { display: none; }
.mascot .m-mouth-idle   { display: block; }
.mascot .m-mouth-smile  { display: none; }
.mascot .m-stars        { opacity: 0; transition: opacity .25s; }
.mascot .m-sign         { opacity: 0; transition: opacity .25s; }
.mascot .m-arm-left, .mascot .m-arm-right { transition: transform .35s ease; transform-origin: center; transform-box: fill-box; }

/* mood-happy：笑眯眯眼 + 微笑 */
.mascot.mood-happy .m-eyes-open    { display: none; }
.mascot.mood-happy .m-eyes-happy   { display: block; }
.mascot.mood-happy .m-mouth-idle   { display: none; }
.mascot.mood-happy .m-mouth-smile  { display: block; }

/* mood-cheer：笑眯眯 + 大笑 + 举手 + 星星 */
.mascot.mood-cheer .m-eyes-open    { display: none; }
.mascot.mood-cheer .m-eyes-happy   { display: block; }
.mascot.mood-cheer .m-mouth-idle   { display: none; }
.mascot.mood-cheer .m-mouth-smile  { display: block; }
.mascot.mood-cheer .m-stars        { opacity: 1; animation: starShine 0.7s ease-in-out infinite alternate; }
.mascot.mood-cheer .m-arm-left  { transform: translate(8px, -56px) rotate(-30deg); }
.mascot.mood-cheer .m-arm-right { transform: translate(-8px, -56px) rotate(30deg); }
@keyframes starShine {
  0%   { transform: scale(1); }
  100% { transform: scale(1.18); }
}

/* mood-encourage：举牌 + 圆眼 */
.mascot.mood-encourage .m-sign { opacity: 1; }
.mascot.mood-encourage .m-arm-left  { transform: translate(20px, -22px) rotate(-25deg); }
.mascot.mood-encourage .m-arm-right { transform: translate(-20px, -22px) rotate(25deg); }

/* 眨眼 */
.mascot.blinking .m-eyes-open circle { opacity: 0; }

/* mascot 跳一下 */
.mascot.mascot-bounce { animation: mBounce .6s ease; }
@keyframes mBounce {
  0%   { transform: translateY(0); }
  30%  { transform: translateY(-22px) rotate(-3deg); }
  55%  { transform: translateY(0) rotate(2deg); }
  75%  { transform: translateY(-8px) rotate(-1deg); }
  100% { transform: translateY(0); }
}

/* ---- 报告页 ---- */
.summary-cards {
  display: flex;
  gap: 12px;
  margin: 16px 0 24px;
  flex-wrap: wrap;
}
.sum-card {
  flex: 1 1 120px;
  padding: 22px;
  border-radius: 22px;
  text-align: center;
  color: #fff;
  box-shadow: var(--shadow);
  font-weight: 700;
}
.sum-card .num { font-size: 48px; font-weight: 800; line-height: 1; margin-bottom: 4px; }
.sum-card.ok    { background: linear-gradient(180deg, #5cd17a, var(--ok)); }
.sum-card.fuzzy { background: linear-gradient(180deg, #ffce5e, var(--fuzzy)); color: #4a3b2a; }
.sum-card.no    { background: linear-gradient(180deg, #ff7574, var(--no)); }

.report-block {
  background: var(--card);
  border: 3px solid var(--border);
  border-radius: 22px;
  padding: 18px 22px;
  margin-bottom: 18px;
  box-shadow: var(--shadow);
}

.chip-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  border-radius: 999px;
  font-size: 18px;
  font-weight: 600;
  background: #f3e2c5;
  color: var(--text);
}
.chip.ok    { background: #dff5e3; color: #2a6b3a; }
.chip.fuzzy { background: #fdebc6; color: #8a6512; }
.chip.no    { background: #fbd6d4; color: #8a2d2c; }
.chip.pending { background: #e7e2d6; color: #6b614e; }
.chip .meta { font-size: 12px; opacity: .7; font-weight: 400; }

.advice div { margin: 6px 0; font-size: 16px; }
.empty { color: var(--muted); font-size: 14px; font-style: italic; }

/* ---- 全屏撒花 canvas ---- */
#celebrate-canvas {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 9999;
}

/* ---- 屏中横幅 ---- */
.banner {
  position: fixed;
  top: 30%;
  left: 50%;
  transform: translate(-50%, -50%) scale(0.5);
  background: linear-gradient(135deg, var(--pink), var(--primary));
  color: #fff;
  padding: 24px 48px;
  border-radius: 32px;
  text-align: center;
  z-index: 9998;
  pointer-events: none;
  opacity: 0;
  box-shadow: 0 12px 40px rgba(255, 138, 61, 0.5);
  border: 4px solid #fff;
  transition: opacity .3s, transform .3s cubic-bezier(0.34, 1.56, 0.64, 1);
}
.banner.show {
  opacity: 1;
  transform: translate(-50%, -50%) scale(1);
}
.banner-main { font-size: 48px; font-weight: 800; line-height: 1.1; }
.banner-sub  { font-size: 22px; margin-top: 6px; opacity: 0.95; }

/* ============================================================ */
/* v2 综合练习样式                                              */
/* ============================================================ */

/* "alt" 主按钮（首页第二个 CTA） */
.big-btn.primary.alt {
  background: linear-gradient(180deg, #74d6a4 0%, #4cb963 100%);
  border-color: #3a9a4f;
  box-shadow: 0 6px 0 #3a9a4f, 0 8px 16px rgba(76,185,99,0.3);
}
.big-btn.primary.alt:hover  { background: linear-gradient(180deg, #87dfb1 0%, #5cc874 100%); }
.big-btn.primary.alt:active { box-shadow: 0 2px 0 #3a9a4f, 0 4px 8px rgba(76,185,99,0.3); transform: translateY(4px); }

/* 综合练习卡片 */
.complex-card {
  padding: 40px 24px;
  text-align: center;
}
.prompt-area {
  font-size: 140px;
  font-weight: 700;
  line-height: 1.1;
  color: #2d2418;
  font-family: "Microsoft YaHei", "PingFang SC", sans-serif;
  text-shadow: 3px 3px 0 rgba(255, 138, 61, 0.18);
  animation: popIn .35s ease;
  word-break: keep-all;
}
.prompt-area .prompt-pinyin {
  font-size: 120px;
  letter-spacing: 4px;
}
.prompt-area .prompt-char {
  display: inline-block;
}
.prompt-area .prompt-emoji {
  font-size: 100px;
  display: block;
  margin-top: 4px;
  filter: drop-shadow(0 4px 6px rgba(0,0,0,0.1));
}
.step-hint {
  margin-top: 12px;
  font-size: 22px;
  color: var(--primary-dark);
  font-weight: 700;
  min-height: 28px;
  animation: popIn .35s ease;
}

/* 选项格子 */
.choices {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
  max-width: 720px;
  margin: 24px auto 16px;
}
.choice {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  min-height: 90px;
  padding: 14px 18px;
  font-size: 36px;
  font-weight: 700;
  border: 3px solid var(--border);
  border-radius: 22px;
  background: var(--card);
  color: var(--text);
  cursor: pointer;
  font-family: inherit;
  box-shadow: var(--shadow);
  transition: transform .12s, background .15s, border-color .15s;
}
.choice:hover { transform: translateY(-2px); background: #fffaf0; }
.choice:active { transform: scale(0.97); }
.choice .opt-emoji { font-size: 48px; line-height: 1; }
.choice .opt-text  { font-size: 32px; margin-top: 2px; }
.choice .opt-pinyin { font-size: 34px; letter-spacing: 1px; font-family: "Microsoft YaHei", "PingFang SC", sans-serif; }
.choice .opt-tone-num { font-size: 44px; font-weight: 800; color: var(--primary-dark); }
.choice .opt-tone-mark { font-size: 56px; line-height: 1; }

.choice.disabled {
  opacity: 0.45;
  cursor: not-allowed;
  pointer-events: none;
  filter: grayscale(0.4);
}
.choice.wrong {
  background: linear-gradient(180deg, #ffd0cf, #fbb4b2);
  border-color: #d6605d;
  color: #8a2d2c;
  animation: shakeX 0.4s;
}
.choice.correct {
  background: linear-gradient(180deg, #c0f0cf, #8dde9f);
  border-color: #3a9a4f;
  color: #1e5a30;
  animation: popIn 0.4s;
}
@keyframes shakeX {
  0%, 100% { transform: translateX(0); }
  20%      { transform: translateX(-10px); }
  40%      { transform: translateX(10px); }
  60%      { transform: translateX(-6px); }
  80%      { transform: translateX(6px); }
}

/* 小屏单列 */
@media (max-width: 600px) {
  .choices { grid-template-columns: 1fr; }
  .prompt-area { font-size: 96px; }
  .prompt-area .prompt-pinyin { font-size: 84px; }
  .prompt-area .prompt-emoji { font-size: 80px; }
  .choice { min-height: 72px; font-size: 30px; }
  .choice .opt-pinyin { font-size: 28px; }
  .choice .opt-tone-num { font-size: 36px; }
  .choice .opt-tone-mark { font-size: 44px; }
}

/* ============================================================ */
/* 拆分拼读·并行模式                                              */
/* ============================================================ */
.bd-slots {
  display: flex;
  flex-direction: column;
  gap: 14px;
  max-width: 720px;
  margin: 8px auto 18px;
}
.bd-slot {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 12px 16px;
  background: var(--card);
  border: 3px solid var(--border);
  border-radius: 20px;
  box-shadow: var(--shadow);
  transition: background .2s, border-color .2s;
}
.bd-slot-label {
  flex: 0 0 60px;
  font-size: 22px;
  font-weight: 700;
  color: var(--primary-dark);
  text-align: center;
}
.bd-slot-choices {
  flex: 1;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
}

.bd-tile {
  min-height: 64px;
  padding: 8px 6px;
  font-size: 26px;
  font-weight: 700;
  border: 2px solid var(--border);
  border-radius: 14px;
  background: #fcf6e9;
  color: var(--text);
  cursor: pointer;
  font-family: inherit;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  transition: transform .12s, background .12s, border-color .12s, box-shadow .12s;
}
.bd-tile:hover { transform: translateY(-1px) scale(1.03); background: #fff; }
.bd-tile:active { transform: scale(0.97); }
.bd-tile.selected {
  background: linear-gradient(180deg, #ffd28b, #ffa05c);
  border-color: var(--primary-dark);
  color: #fff;
  box-shadow: 0 3px 0 var(--primary-dark);
  transform: translateY(-1px);
}
.bd-tile.frozen { cursor: not-allowed; opacity: 0.65; }
.bd-tile.frozen:hover { transform: none; }
.bd-tile .opt-tone-mark {
  font-size: 56px;
  line-height: 0.7;
  font-weight: 900;
  /* 让 Unicode 修饰符号（ˉ ˊ ˇ ˋ）更清晰、更粗壮一些 */
  font-family: "Microsoft YaHei", "PingFang SC", "Arial", sans-serif;
  display: inline-block;
  transform: translateY(-2px);
}
.bd-tile .opt-tone-num  { font-size: 16px; color: inherit; opacity: 0.85; margin-top: 4px; }

/* slot 结果反馈 */
.bd-slot.result-correct {
  background: linear-gradient(180deg, #e3f7e8, #c9efd2);
  border-color: var(--ok);
}
.bd-slot.result-correct .bd-slot-label::before { content: '✓ '; color: var(--ok); }
.bd-slot.result-correct .bd-tile.selected {
  background: linear-gradient(180deg, #6ed489, var(--ok));
  border-color: #3a9a4f;
  box-shadow: 0 3px 0 #3a9a4f;
}
.bd-slot.result-wrong {
  background: linear-gradient(180deg, #ffe6e5, #fbcbca);
  border-color: var(--no);
  animation: shakeX 0.4s;
}
.bd-slot.result-wrong .bd-slot-label::before { content: '✗ '; color: var(--no); }
.bd-slot.result-wrong .bd-tile.selected {
  background: linear-gradient(180deg, #ff8a89, var(--no));
  border-color: #c83b39;
  color: #fff;
}

/* 实时拼读回显 */
.bd-assembly {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 14px;
  margin: 14px auto 0;
  padding: 12px 24px;
  background: #fff8e1;
  border: 3px dashed #ffce5e;
  border-radius: 20px;
  max-width: 720px;
  animation: popIn .3s ease;
}
.bd-assembly-label {
  font-size: 20px;
  color: #8a6512;
  font-weight: 700;
  flex-shrink: 0;
}
.bd-assembly-result {
  font-size: 56px;
  font-weight: 800;
  letter-spacing: 2px;
  color: var(--primary-dark);
  font-family: "Microsoft YaHei", "PingFang SC", sans-serif;
  line-height: 1;
  min-width: 100px;
  text-align: center;
}
.bd-assembly-result.empty {
  color: #c8b89a;
  font-size: 36px;
  letter-spacing: 10px;
  font-weight: 600;
}

/* 提交按钮 */
.submit-btn {
  display: block;
  margin: 14px auto 0;
  max-width: 380px;
  width: 100%;
}
.submit-btn:disabled {
  background: #d6cfbe;
  color: #8b8270;
  border-color: #b8af9a;
  box-shadow: 0 3px 0 #b8af9a;
  cursor: not-allowed;
  transform: none;
  filter: grayscale(0.3);
}
.submit-btn:not(:disabled):hover { animation: nudge 0.6s ease-in-out infinite; }
@keyframes nudge {
  0%, 100% { transform: translateY(-2px) rotate(-0.5deg); }
  50%      { transform: translateY(-4px) rotate(0.5deg); }
}

/* 小屏：slot 改为纵向，选项依旧 4 个一行（小一点） */
@media (max-width: 600px) {
  .bd-slot {
    flex-direction: column;
    align-items: stretch;
    padding: 10px 12px;
    gap: 8px;
  }
  .bd-slot-label { text-align: left; flex: initial; font-size: 18px; }
  .bd-slot-choices { gap: 6px; }
  .bd-tile { min-height: 56px; font-size: 22px; }
  .bd-tile .opt-tone-mark { font-size: 26px; }
  .bd-tile .opt-tone-num  { font-size: 13px; }
  .bd-assembly { padding: 10px 16px; gap: 8px; }
  .bd-assembly-label { font-size: 16px; }
  .bd-assembly-result { font-size: 44px; min-width: 80px; }
  .bd-assembly-result.empty { font-size: 28px; letter-spacing: 6px; }
}

/* ---- 小屏 ---- */
@media (max-width: 600px) {
  .pinyin-display { font-size: 110px; letter-spacing: 4px; }
  .topbar { padding: 12px 16px; }
  .logo { font-size: 22px; }
  h2 { font-size: 26px; }
  .home-mascot { width: 150px; height: 165px; }
  .speech-bubble { font-size: 17px; padding: 12px 16px; margin-bottom: 30px; }
  .practice-mascot { width: 100px; height: 110px; }
  .banner-main { font-size: 36px; }
  .banner-sub  { font-size: 18px; }
}