:root{--bg: #2e8b57;--bg-grad: linear-gradient(160deg, #3cb371 0%, #2e8b57 55%, #1f6b43 100%);--card: #ffffff;--surface: #f3faf5;--ink: #1c2b22;--muted: #6b8478;--accent: #2e8b57;--accent-deep: #1f6b43;--correct: #34c759;--wrong: #ff453a;--line: #dcebe1;--line: #d8ebe0;--shadow: 0 12px 36px rgba(20, 70, 45, .22);--radius: 18px}*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}html,body,#root{height:100%;margin:0}body{font-family:-apple-system,PingFang SC,Microsoft YaHei,sans-serif;background:var(--bg-grad);background-attachment:fixed;color:var(--ink)}.app{min-height:100%;display:flex;flex-direction:column;align-items:center;justify-content:center;padding:max(16px,env(safe-area-inset-top)) 16px max(16px,env(safe-area-inset-bottom))}.stage{width:100%;max-width:560px;background:var(--card);border-radius:var(--radius);box-shadow:var(--shadow);padding:28px 24px}.title{font-size:28px;font-weight:700;margin:0 0 6px;text-align:center}.subtitle{color:var(--muted);text-align:center;margin:0 0 24px;font-size:15px}.tier-list{display:flex;flex-direction:column;gap:14px}.tier-btn{display:flex;align-items:center;justify-content:space-between;padding:18px 20px;border:2px solid var(--line);border-radius:14px;background:var(--surface);cursor:pointer;transition:transform .12s,border-color .12s}.tier-btn:active{transform:scale(.98)}.tier-btn:hover{border-color:var(--accent)}.tier-btn .name{font-size:19px;font-weight:600}.tier-btn .desc{font-size:13px;color:var(--muted);margin-top:2px}.tier-dot{width:14px;height:14px;border-radius:50%}.hud{display:flex;justify-content:space-between;align-items:center;margin-bottom:22px;font-size:15px;color:var(--muted)}.hud .score{font-weight:700;color:var(--ink)}.progress-bar{height:6px;border-radius:3px;background:var(--line);overflow:hidden;margin-bottom:26px}.progress-fill{height:100%;background:var(--accent);transition:width .3s ease}.idiom{display:flex;justify-content:center;gap:10px;margin:10px 0 18px}.char{width:64px;height:64px;display:flex;align-items:center;justify-content:center;font-size:34px;font-weight:600;color:var(--ink);background:var(--surface);border:1px solid var(--line);border-radius:12px}.char.blank{background:#fff;border:2px dashed var(--accent);color:var(--accent)}.char.blank.filled{border-style:solid}.meaning{text-align:center;color:var(--muted);font-size:15px;line-height:1.5;margin:0 0 26px;min-height:22px}.options{display:grid;grid-template-columns:1fr 1fr;gap:14px}.option{padding:18px;font-size:26px;font-weight:600;color:var(--ink);border:2px solid var(--line);border-radius:14px;background:#fff;cursor:pointer;transition:transform .1s,background .15s,border-color .15s}.option:active{transform:scale(.97)}.option:hover:not(:disabled){border-color:var(--accent)}.option:disabled{cursor:default}.option.correct{background:var(--correct);border-color:var(--correct);color:#fff}.option.wrong{background:var(--wrong);border-color:var(--wrong);color:#fff}.feedback{text-align:center;margin:22px 0 0;font-size:17px;font-weight:600;min-height:24px}.feedback.ok{color:var(--correct)}.feedback.no{color:var(--wrong)}.next-btn,.primary-btn{width:100%;margin-top:22px;padding:16px;font-size:17px;font-weight:600;color:#fff;background:var(--accent);border:none;border-radius:14px;cursor:pointer}.next-btn:active,.primary-btn:active{opacity:.85}.result-score{text-align:center;font-size:64px;font-weight:800;margin:10px 0 4px;color:var(--accent)}.result-total{text-align:center;color:var(--muted);margin:0 0 8px;font-size:16px}.result-comment{text-align:center;font-size:18px;margin:6px 0 24px}@media (orientation: landscape) and (min-width: 700px){.stage{max-width:720px;padding:36px 48px}.char{width:78px;height:78px;font-size:40px}.options{grid-template-columns:repeat(4,1fr)}}.toggles{display:flex;gap:12px;margin-top:22px}.toggle{flex:1;padding:12px;font-size:15px;font-weight:600;color:var(--muted);background:var(--surface);border:2px solid var(--line);border-radius:12px;cursor:pointer;transition:color .15s,border-color .15s,background .15s}.toggle.on{color:var(--accent-deep);border-color:var(--accent);background:#eaf7ef}.toggle:active{transform:scale(.97)}.speak-btn{width:64px;height:64px;display:flex;align-items:center;justify-content:center;font-size:26px;background:var(--accent);color:#fff;border:none;border-radius:12px;cursor:pointer;transition:opacity .15s,transform .1s}.speak-btn:active{transform:scale(.94);opacity:.85}@media (orientation: landscape) and (min-width: 700px){.speak-btn{width:78px;height:78px}}