/* ============ Reset & Variables ============ */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
:root {
  --c1: #FF6B6B; --c2: #4ECDC4; --c3: #FFE66D; --c4: #A78BFA;
  --c5: #F97316; --c6: #3B82F6; --c7: #EC4899; --c8: #10B981;
  --text: #2D3436; --sub: #636E72;
  --shadow: 0 4px 20px rgba(0,0,0,.08);
  --radius: 24px; --radius-sm: 16px; --radius-xs: 12px;
}
html { font-size: 16px; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Noto Sans SC", "Microsoft YaHei", sans-serif;
  background: linear-gradient(160deg, #FFF5F0 0%, #FFE8D6 30%, #E8F4FD 70%, #F0E6FF 100%);
  min-height: 100vh; display: flex; justify-content: center; align-items: flex-start;
  padding: 16px; color: var(--text);
  -webkit-tap-highlight-color: transparent; user-select: none;
}
.container { width: 100%; max-width: 520px; margin: 0 auto; }

/* ============ Screens & Animations ============ */
.screen { display: none; }
.screen.active { display: block; animation: fadeIn .35s ease; }
@keyframes fadeIn { from{opacity:0;transform:translateY(12px)} to{opacity:1;transform:translateY(0)} }
@keyframes bounceUp { 0%{transform:translateY(40px);opacity:0} 50%{transform:translateY(-8px)} 100%{transform:translateY(0);opacity:1} }
@keyframes shake { 0%,100%{transform:translateX(0)} 20%{transform:translateX(-8px)} 40%{transform:translateX(8px)} 60%{transform:translateX(-6px)} 80%{transform:translateX(6px)} }
@keyframes pulse { 0%,100%{transform:scale(1)} 50%{transform:scale(1.08)} }
@keyframes float { 0%,100%{transform:translateY(0)} 50%{transform:translateY(-10px)} }
@keyframes confettiFall { 0%{transform:translateY(-100px) rotate(0deg);opacity:1} 100%{transform:translateY(105vh) rotate(720deg);opacity:0} }
@keyframes starPop { 0%{transform:scale(0) rotate(-30deg);opacity:0} 60%{transform:scale(1.3) rotate(5deg)} 100%{transform:scale(1) rotate(0deg);opacity:1} }

/* ============ Header ============ */
.header { text-align: center; padding: 24px 0 8px; }
.header .logo {
  font-size: 2.4rem; font-weight: 900;
  background: linear-gradient(135deg, var(--c1), var(--c5), var(--c7));
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
  margin-bottom: 4px;
}
.header .subtitle { color: var(--sub); font-size: .95rem; letter-spacing: 2px; }

/* ============ User Bar ============ */
.user-bar {
  display: flex; align-items: center; justify-content: space-between;
  background: #fff; border-radius: var(--radius-sm); padding: 12px 20px;
  margin-bottom: 16px; box-shadow: var(--shadow);
}
.user-info { display: flex; align-items: center; gap: 10px; }
.avatar { font-size: 1.8rem; }
.username { font-weight: 700; font-size: .95rem; }
.logout-btn {
  background: none; border: 1px solid #E0E0E0; border-radius: 8px;
  padding: 6px 14px; font-size: .82rem; color: var(--sub); cursor: pointer; font-family: inherit;
}
.logout-btn:hover { border-color: var(--c1); color: var(--c1); }

/* ============ Auth ============ */
.auth-card { background: #fff; border-radius: var(--radius); padding: 36px 28px; box-shadow: var(--shadow); text-align: center; }
.auth-icon { font-size: 3.5rem; margin-bottom: 8px; }
.auth-title { font-size: 1.4rem; font-weight: 700; margin-bottom: 20px; }
.auth-form { text-align: left; }
.auth-form label { display: block; font-size: .88rem; font-weight: 700; margin: 14px 0 6px; }
.auth-form input {
  width: 100%; border: 2px solid #E8E8E8; border-radius: var(--radius-xs);
  padding: 14px 16px; font-size: 1rem; font-family: inherit; outline: none; transition: border-color .2s;
}
.auth-form input:focus { border-color: var(--c6); }
.form-error { color: var(--c1); font-size: .82rem; margin-top: 8px; min-height: 20px; }
.auth-switch { margin-top: 16px; font-size: .9rem; color: var(--sub); }
.auth-switch a { color: var(--c6); cursor: pointer; font-weight: 700; text-decoration: none; }

/* ============ Subject Cards（三入口） ============ */
.subject-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; margin-bottom: 16px; }
.subject-card {
  background: #fff; border-radius: var(--radius); padding: 24px 12px; text-align: center;
  box-shadow: var(--shadow); cursor: pointer; transition: all .25s; border: 3px solid transparent;
}
.subject-card:hover { transform: translateY(-4px); box-shadow: 0 10px 30px rgba(0,0,0,.14); }
.subject-card:active { transform: scale(.96); }
.subject-icon { font-size: 3rem; display: block; margin-bottom: 10px; }
.subject-name { font-size: 1.3rem; font-weight: 900; margin-bottom: 4px; }
.subject-desc { font-size: .72rem; color: var(--sub); line-height: 1.4; }
.subj-chinese { border-color: #FFD4D4; background: linear-gradient(160deg,#fff,#FFF5F5); }
.subj-chinese .subject-name { color: #E74C3C; }
.subj-math { border-color: #C4E8FF; background: linear-gradient(160deg,#fff,#F0F8FF); }
.subj-math .subject-name { color: #2E86DE; }
.subj-english { border-color: #C8F0DC; background: linear-gradient(160deg,#fff,#F2FCF6); }
.subj-english .subject-name { color: #10B981; }

/* ============ Activity Cards ============ */
.act-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px; }
.act-card {
  background: #fff; border-radius: var(--radius-sm); padding: 20px 16px; text-align: center;
  box-shadow: var(--shadow); cursor: pointer; transition: all .2s; border: 2px solid #F0F0F0;
}
.act-card:hover { transform: translateY(-3px); border-color: var(--c4); }
.act-card:active { transform: scale(.96); }
.act-icon { font-size: 2.4rem; display: block; margin-bottom: 8px; }
.act-title { font-size: 1.05rem; font-weight: 700; margin-bottom: 4px; }
.act-desc { font-size: .75rem; color: var(--sub); }

/* ============ Generic Card ============ */
.card {
  background: #fff; border-radius: var(--radius); padding: 26px 22px; margin-bottom: 16px;
  box-shadow: var(--shadow); border: 2px solid transparent; transition: all .25s; cursor: pointer;
}
.card:hover { transform: translateY(-3px); box-shadow: 0 8px 30px rgba(0,0,0,.12); }
.card:active { transform: scale(.97); }
.card-icon { font-size: 2.6rem; margin-bottom: 10px; display: block; }
.card-title { font-size: 1.25rem; font-weight: 700; margin-bottom: 6px; }
.card-desc { font-size: .88rem; color: var(--sub); line-height: 1.5; }
.card.accent1 { border-color: #FFD4D4; background: linear-gradient(135deg,#fff,#FFF5F5); }
.card.accent2 { border-color: #C4F1E7; background: linear-gradient(135deg,#fff,#F5FFFD); }
.card.accent3 { border-color: #FFF3C4; background: linear-gradient(135deg,#fff,#FFFEF5); }
.card.accent4 { border-color: #E0D4FF; background: linear-gradient(135deg,#fff,#F9F5FF); }

/* ============ Buttons ============ */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  border: none; border-radius: var(--radius-xs); padding: 14px 28px;
  font-size: 1rem; font-weight: 700; cursor: pointer; transition: all .2s; font-family: inherit; min-height: 48px;
}
.btn:active { transform: scale(.95); }
.btn-primary { background: linear-gradient(135deg, var(--c1), var(--c5)); color: #fff; box-shadow: 0 4px 14px rgba(255,107,107,.35); }
.btn-success { background: linear-gradient(135deg, var(--c2), var(--c8)); color: #fff; box-shadow: 0 4px 14px rgba(78,205,196,.35); }
.btn-outline { background: #fff; color: var(--text); border: 2px solid #E0E0E0; }
.btn-lg { padding: 16px 36px; font-size: 1.15rem; min-height: 56px; border-radius: var(--radius); }
.btn-block { width: 100%; }
.btn:disabled { opacity: .5; pointer-events: none; }

/* ============ Game Top Bar ============ */
.game-topbar {
  display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 8px;
  background: #fff; border-radius: var(--radius-sm); padding: 12px 18px; margin-bottom: 16px; box-shadow: var(--shadow);
}
.game-id { font-weight: 700; font-size: 1rem; display: flex; align-items: center; gap: 6px; }
.game-stats { display: flex; align-items: center; gap: 14px; }
.stat { display: flex; align-items: center; gap: 4px; font-weight: 700; font-size: .95rem; }
.stat-score { color: var(--c5); }
.stat-progress { color: var(--c4); }
.stat-timer { color: var(--c1); font-variant-numeric: tabular-nums; }
.stat-timer.urgent { animation: pulse .6s infinite; }

/* ============ Question Card ============ */
.question-card {
  background: #fff; border-radius: var(--radius); padding: 28px 20px; text-align: center;
  box-shadow: var(--shadow); min-height: 200px;
  display: flex; flex-direction: column; align-items: center; justify-content: center;
}
.question-label { font-size: .9rem; color: var(--sub); margin-bottom: 10px; letter-spacing: 1px; }
.question-emoji { font-size: 2.2rem; animation: float 2s ease-in-out infinite; }
.question-text { font-size: 3rem; font-weight: 900; letter-spacing: 4px; margin: 8px 0; line-height: 1.3; word-break: break-word; }

/* 拼音 ruby */
ruby { ruby-align: center; }
rt { font-size: .35em; color: var(--sub); font-weight: 400; letter-spacing: 0; }

/* 语文/英语题型 */
.big-zi { font-size: 4rem; font-weight: 900; line-height: 1.2; }
.big-zi.small { font-size: 3rem; }
.py-line { font-size: 1rem; color: var(--sub); margin-top: 10px; letter-spacing: 1px; font-weight: 400; }
.q-sentence { font-size: 1.6rem; font-weight: 800; line-height: 1.5; letter-spacing: 1px; }
.word-en { font-size: 2.6rem; font-weight: 900; color: var(--c6); letter-spacing: 2px; }
.word-emoji { font-size: 4rem; }
.listen-hint { font-size: 4rem; animation: pulse 1.2s infinite; }

/* 语音按钮 */
.audio-btn {
  margin-top: 12px; display: inline-flex; align-items: center; gap: 6px;
  background: linear-gradient(135deg, var(--c4), var(--c6)); color: #fff;
  border: none; border-radius: 30px; padding: 10px 22px; font-size: 1rem; font-weight: 700;
  cursor: pointer; font-family: inherit; box-shadow: 0 4px 12px rgba(167,139,250,.4);
}
.audio-btn:active { transform: scale(.94); }

/* 阅读理解短文 */
.reading-box {
  margin-top: 14px; background: #FFFBEA; border: 2px dashed var(--c3);
  border-radius: var(--radius-xs); padding: 16px; text-align: left; width: 100%;
}
.reading-title { font-size: 1.05rem; font-weight: 800; margin-bottom: 8px; text-align: center; }
.reading-text { font-size: 1.05rem; line-height: 1.9; color: var(--text); }
.reading-py { font-size: .78rem; color: var(--sub); line-height: 1.6; margin-top: 8px; }

/* ============ 选择题选项 ============ */
.ans-options { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-top: 18px; }
.ans-options:has(.opt-btn:nth-child(3):last-child) { grid-template-columns: 1fr; }
.opt-btn {
  background: #fff; border: 3px solid #E8E8E8; border-radius: var(--radius-sm);
  padding: 20px 12px; font-size: 1.5rem; font-weight: 800; cursor: pointer;
  font-family: inherit; transition: all .15s; color: var(--text); min-height: 60px;
  display: flex; align-items: center; justify-content: center; gap: 8px;
}
.opt-btn:hover { border-color: var(--c6); transform: translateY(-2px); }
.opt-btn:active { transform: scale(.96); }
.opt-btn.correct { border-color: var(--c8); background: #F0FFF6; animation: pulse .4s; }
.opt-btn.wrong { border-color: var(--c1); background: #FFF5F5; animation: shake .4s; }
.opt-emoji { font-size: 1.6rem; }

/* ============ 填空（数学） ============ */
.answer-area { margin-top: 18px; display: flex; flex-direction: column; gap: 12px; }
.answer-row { display: flex; gap: 12px; align-items: center; }
.answer-input {
  flex: 1; border: 3px solid #E8E8E8; border-radius: var(--radius-xs);
  padding: 16px 20px; font-size: 1.5rem; font-weight: 700; text-align: center;
  font-family: inherit; outline: none; transition: border-color .2s; min-width: 0; -moz-appearance: textfield;
}
.answer-input::-webkit-inner-spin-button, .answer-input::-webkit-outer-spin-button { -webkit-appearance: none; margin: 0; }
.answer-input:focus { border-color: var(--c6); }
.answer-input.correct { border-color: var(--c8) !important; background: #F0FFF6; animation: pulse .4s; }
.answer-input.wrong { border-color: var(--c1) !important; background: #FFF5F5; animation: shake .4s; }

/* 数字键盘 */
.numpad { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; }
.np-btn {
  background: #F8F9FA; border: 2px solid #E8E8E8; border-radius: var(--radius-xs);
  padding: 14px 0; font-size: 1.3rem; font-weight: 700; cursor: pointer; font-family: inherit; transition: all .15s; min-height: 48px;
}
.np-btn:active { background: #E8E8E8; transform: scale(.93); }
.np-submit { background: linear-gradient(135deg, var(--c2), var(--c8)); color: #fff; border-color: transparent; grid-row: span 2; }
.np-del { background: #FFF0F0; color: var(--c1); border-color: #FFD4D4; font-size: 1rem; }
.np-empty { background: transparent; border: none; pointer-events: none; }

/* ============ 书写画布 ============ */
.ans-write { margin-top: 18px; text-align: center; }
.write-pinyin { font-size: 1rem; color: var(--sub); margin-bottom: 8px; font-weight: 600; }
.write-canvas {
  background: #fff; border: 3px solid #E8E8E8; border-radius: var(--radius-sm);
  touch-action: none; cursor: crosshair; display: block; margin: 0 auto;
}
.write-actions { display: flex; gap: 12px; justify-content: center; margin-top: 14px; }

/* ============ Feedback ============ */
.overlay { position: fixed; inset: 0; background: rgba(0,0,0,.35); z-index: 99; display: none; }
.overlay.show { display: block; }
.feedback {
  position: fixed; top: 50%; left: 50%; transform: translate(-50%, -50%) scale(0);
  background: #fff; border-radius: var(--radius); padding: 32px 40px; text-align: center;
  box-shadow: 0 16px 60px rgba(0,0,0,.2); z-index: 100;
  transition: transform .25s cubic-bezier(.175,.885,.32,1.275); pointer-events: none;
  max-width: 85vw;
}
.feedback.show { transform: translate(-50%, -50%) scale(1); }
.fb-icon { font-size: 4rem; display: block; margin-bottom: 8px; }
.fb-text { font-size: 1.3rem; font-weight: 700; }
.fb-answer { font-size: 1rem; color: var(--sub); margin-top: 4px; }
.fb-points { font-size: 1.1rem; font-weight: 700; color: var(--c5); margin-top: 6px; }

/* ============ Level Grid ============ */
.level-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin: 20px 0; }
.level-btn {
  background: #fff; border: 2px solid #E8E8E8; border-radius: var(--radius-sm);
  padding: 20px 12px; text-align: center; cursor: pointer; transition: all .2s; font-family: inherit;
}
.level-btn:hover:not(.locked) { transform: translateY(-2px); box-shadow: var(--shadow); }
.level-btn:active:not(.locked) { transform: scale(.95); }
.lv-num { font-size: 1.8rem; font-weight: 900; }
.lv-label { font-size: .78rem; color: var(--sub); margin-top: 4px; }
.lv-stars { font-size: 1rem; margin-top: 4px; }
.level-btn.locked { opacity: .4; pointer-events: none; background: #F5F5F5; }
.level-btn.done { border-color: var(--c3); background: #FFFEF5; }

/* ============ Result ============ */
.result-card { background: #fff; border-radius: var(--radius); padding: 36px 28px; text-align: center; box-shadow: var(--shadow); }
.result-icon { font-size: 2.5rem; }
.result-stars { font-size: 3.5rem; margin: 12px 0; }
.result-stars .star { display: inline-block; animation: starPop .5s ease backwards; }
.result-stars .star:nth-child(1) { animation-delay: .2s; }
.result-stars .star:nth-child(2) { animation-delay: .4s; }
.result-stars .star:nth-child(3) { animation-delay: .6s; }
.result-score { font-size: 2.5rem; font-weight: 900; color: var(--c5); }
.result-stats { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin: 24px 0; }
.result-stat { background: #F8F9FA; border-radius: var(--radius-xs); padding: 16px 8px; }
.rs-val { font-size: 1.4rem; font-weight: 700; }
.rs-label { font-size: .78rem; color: var(--sub); margin-top: 2px; }
.result-msg { font-size: 1.1rem; color: var(--sub); margin: 8px 0 20px; }
.result-actions { display: flex; gap: 12px; flex-wrap: wrap; justify-content: center; }

/* ============ Progress ============ */
.progress-section { background: #fff; border-radius: var(--radius); padding: 24px; margin-bottom: 16px; box-shadow: var(--shadow); }
.progress-section h3 { font-size: 1.1rem; margin-bottom: 16px; display: flex; align-items: center; gap: 8px; }
.progress-overview { display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px; }
.progress-item { background: #F8F9FA; border-radius: var(--radius-xs); padding: 16px; text-align: center; }
.pv { font-size: 1.6rem; font-weight: 900; }
.pl { font-size: .8rem; color: var(--sub); margin-top: 2px; }
.accent-green .pv { color: var(--c8); }
.accent-orange .pv { color: var(--c5); }
.accent-purple .pv { color: var(--c4); }
.accent-blue .pv { color: var(--c6); }

.subj-stat {
  background: #F8F9FA; border-radius: var(--radius-xs); padding: 14px 16px; margin-bottom: 10px;
  display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 8px;
}
.subj-name { font-weight: 800; font-size: 1rem; }
.subj-nums { display: flex; gap: 14px; font-size: .82rem; color: var(--sub); flex-wrap: wrap; }
.subj-nums b { color: var(--text); }

.history-list { list-style: none; }
.history-item { display: flex; align-items: center; justify-content: space-between; padding: 12px 0; border-bottom: 1px solid #F0F0F0; font-size: .85rem; gap: 8px; flex-wrap: wrap; }
.history-item:last-child { border-bottom: none; }
.history-mode { font-weight: 700; }
.history-score { color: var(--c5); font-weight: 700; }
.history-time { color: var(--sub); font-size: .78rem; }
.empty-state { text-align: center; padding: 32px; color: var(--sub); font-size: .95rem; }

/* ============ Misc ============ */
.confetti-container { position: fixed; inset: 0; pointer-events: none; z-index: 200; overflow: hidden; }
.confetti-piece { position: absolute; width: 12px; height: 12px; top: -20px; border-radius: 3px; animation: confettiFall linear forwards; }
.loading-overlay {
  position: fixed; inset: 0; background: rgba(255,255,255,.9); display: flex;
  align-items: center; justify-content: center; z-index: 500; backdrop-filter: blur(4px);
}
.spinner { font-size: 3rem; animation: float 1s ease-in-out infinite; }
.sub-title { font-size: 1.2rem; font-weight: 700; text-align: center; margin: 16px 0; }
.difficulty-options { display: flex; flex-direction: column; gap: 12px; margin: 16px 0; }
.diff-btn {
  background: #fff; border: 2px solid #E8E8E8; border-radius: var(--radius-sm);
  padding: 18px 20px; cursor: pointer; text-align: left; font-family: inherit; transition: all .2s; width: 100%;
}
.diff-btn:hover { border-color: var(--c4); box-shadow: var(--shadow); }
.diff-btn:active { transform: scale(.97); }
.diff-name { font-size: 1.1rem; font-weight: 700; display: block; }
.diff-desc { font-size: .82rem; color: var(--sub); margin-top: 4px; display: block; }
.diff-icon { font-size: 1.5rem; float: right; }
.time-options { display: flex; gap: 12px; margin: 16px 0; }
.time-btn {
  flex: 1; background: #fff; border: 2px solid #E8E8E8; border-radius: var(--radius-sm);
  padding: 20px 12px; cursor: pointer; text-align: center; font-family: inherit; font-size: 1.4rem; font-weight: 700; transition: all .2s;
}
.time-btn:hover { border-color: var(--c1); box-shadow: var(--shadow); }
.time-btn:active { transform: scale(.95); }
.back-row { margin-bottom: 16px; }
.back-link { display: inline-flex; align-items: center; gap: 6px; color: var(--sub); font-size: .9rem; cursor: pointer; background: none; border: none; font-family: inherit; padding: 8px 4px; }

/* ============ Responsive ============ */
@media (max-width: 480px) {
  html { font-size: 15px; }
  .header .logo { font-size: 2rem; }
  .question-text { font-size: 2.4rem; letter-spacing: 2px; }
  .big-zi { font-size: 3.4rem; }
  .q-sentence { font-size: 1.4rem; }
  .word-en { font-size: 2.1rem; }
  .np-btn { padding: 12px 0; font-size: 1.15rem; }
  .opt-btn { font-size: 1.3rem; padding: 18px 10px; }
  .subject-icon { font-size: 2.4rem; }
  .subject-name { font-size: 1.1rem; }
  .subject-desc { font-size: .66rem; }
}
@media (max-width: 360px) {
  html { font-size: 14px; }
  .subject-grid { gap: 8px; }
  .subject-card { padding: 18px 8px; }
  .question-text { font-size: 2rem; }
  .numpad { gap: 5px; }
}