:root{--bg:#f4f6fb;--card:#fff;--text:#1f2328;--muted:#6b7280;--line:#e5e7eb;--primary:#1f6feb;--primary-ink:#fff;--ok:#1a7f37;--ok-bg:#e6f4ea;--bad:#cf222e;--bad-bg:#fdecee;--warn:#d4a72c;--radius:16px;--shadow:0 1px 2px #1018280f, 0 4px 16px #1018280f;color:var(--text);background:var(--bg);-webkit-font-smoothing:antialiased;font-family:-apple-system,BlinkMacSystemFont,PingFang SC,Hiragino Sans GB,Microsoft YaHei,Segoe UI,Roboto,sans-serif}*{box-sizing:border-box}html,body,#root{min-height:100%;margin:0}body{background:var(--bg)}button{font:inherit;cursor:pointer}input,textarea{font:inherit}.app{flex-direction:column;max-width:520px;min-height:100vh;margin:0 auto;padding-bottom:72px;display:flex}.topbar{justify-content:space-between;align-items:center;gap:8px;padding:14px 16px 8px;display:flex}.topbar h1{margin:0;font-size:18px;font-weight:700}.pill{background:var(--card);box-shadow:var(--shadow);border-radius:999px;align-items:center;gap:4px;padding:4px 10px;font-size:13px;font-weight:600;display:inline-flex}.pill.fire{color:#d4480f}.pill.xp{color:var(--primary)}.pill.ok{color:var(--ok);background:var(--ok-bg);box-shadow:none}button.list-item{font:inherit;color:inherit;-webkit-tap-highlight-color:transparent;padding:10px 6px}button.list-item:active{background:#1f6feb14!important}.tabbar{-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);border-top:1px solid var(--line);padding-bottom:env(safe-area-inset-bottom);z-index:10;background:#ffffffeb;justify-content:center;display:flex;position:fixed;bottom:0;left:0;right:0}.tabbar-inner{width:100%;max-width:520px;display:flex}.tab{color:var(--muted);background:0 0;border:0;flex-direction:column;flex:1;align-items:center;gap:2px;padding:8px 0 6px;font-size:11px;display:flex}.tab .ico{font-size:20px}.tab.active{color:var(--primary);font-weight:700}.tab .badge-dot{background:var(--bad);color:#fff;border-radius:999px;margin-top:-2px;margin-left:22px;padding:0 5px;font-size:10px;line-height:16px;position:absolute}.page{flex-direction:column;gap:14px;padding:0 16px 24px;display:flex}.card{background:var(--card);border-radius:var(--radius);box-shadow:var(--shadow);padding:16px}.card h2{margin:0 0 6px;font-size:17px}.card h3{margin:0 0 6px;font-size:15px}.muted{color:var(--muted);font-size:13px}.row{align-items:center;gap:10px;display:flex}.row.between{justify-content:space-between}.grid2{grid-template-columns:1fr 1fr;gap:10px;display:grid}.stat{text-align:center}.stat .num{font-size:22px;font-weight:800}.stat .lab{color:var(--muted);font-size:12px}.btn{background:var(--primary);color:var(--primary-ink);border:0;border-radius:12px;justify-content:center;align-items:center;gap:8px;padding:12px 16px;font-size:15px;font-weight:700;transition:transform 50ms,opacity .2s;display:inline-flex}.btn:active{transform:scale(.98)}.btn:disabled{opacity:.5;cursor:default}.btn.block{width:100%}.btn.ghost{background:var(--card);color:var(--text);box-shadow:inset 0 0 0 1.5px var(--line)}.btn.ok{background:var(--ok)}.btn.bad{background:var(--bad)}.btn.small{border-radius:10px;padding:8px 12px;font-size:13px}.btn.icon{border-radius:50%;width:44px;height:44px;padding:0;font-size:18px}.progress{background:#e5e9f2;border-radius:999px;flex:1;height:10px;overflow:hidden}.progress>div{background:var(--primary);border-radius:999px;height:100%;transition:width .3s}.hero{color:#fff;box-shadow:var(--shadow);background:linear-gradient(135deg,#1f6feb,#8957e5);border-radius:20px;padding:20px}.hero h2{margin:0 0 4px;font-size:20px}.hero .sub{opacity:.9;font-size:14px}.hero .btn{color:#1f6feb;background:#fff;margin-top:14px}.world{border-radius:var(--radius);background:var(--card);box-shadow:var(--shadow);overflow:hidden}.world-head{color:#fff;justify-content:space-between;align-items:center;padding:14px 16px;display:flex}.world-head h3{margin:0;font-size:16px}.world-head .tag{opacity:.9;font-size:12px}.levels{flex-direction:column;display:flex}.level{border-top:1px solid var(--line);text-align:left;background:0 0;border-bottom:0;border-left:0;border-right:0;align-items:center;gap:12px;width:100%;padding:12px 16px;display:flex}.level:disabled{opacity:.5;cursor:default}.level .num{color:#fff;border-radius:50%;flex-shrink:0;justify-content:center;align-items:center;width:36px;height:36px;font-weight:800;display:flex}.level .info{flex:1}.level .info .t{font-size:15px;font-weight:700}.level .info .s{color:var(--muted);font-size:12px}.stars{color:var(--warn);letter-spacing:1px;font-size:14px}.teach h2{margin:0 0 12px;font-size:20px}.teach p{margin:0 0 10px;font-size:15px;line-height:1.6}.example{background:#f6f8fc;border-radius:12px;align-items:center;gap:10px;margin-top:8px;padding:10px 12px;display:flex}.example .en{font-size:16px;font-weight:700}.example .zh{color:var(--muted);font-size:13px}.example .note{color:var(--primary);font-size:12px}.example .body{flex:1}.exercise{flex-direction:column;gap:14px;display:flex}.prompt{color:var(--muted);letter-spacing:.3px;font-size:13px;font-weight:600}.sentence-big{font-size:22px;font-weight:800;line-height:1.4}.sentence-zh{color:var(--text);font-size:16px}.spoken{color:#8957e5;font-size:13px}.blank{border-bottom:3px solid var(--primary);text-align:center;min-width:64px;color:var(--primary);margin:0 4px;display:inline-block}.options{flex-direction:column;gap:10px;display:flex}.options.grid{grid-template-columns:1fr 1fr;display:grid}.opt{border:2px solid var(--line);background:var(--card);text-align:left;border-radius:14px;padding:14px;font-size:16px;line-height:1.4}.opt.selected{border-color:var(--primary)}.opt.right{border-color:var(--ok);background:var(--ok-bg)}.opt.wrong{border-color:var(--bad);background:var(--bad-bg)}.opt:disabled{cursor:default}.tiles{border:2px dashed var(--line);background:#f6f8fc;border-radius:14px;flex-wrap:wrap;gap:8px;min-height:52px;padding:10px;display:flex}.tile{border:2px solid var(--line);background:#fff;border-radius:10px;padding:8px 12px;font-size:16px;font-weight:600}.tile.used{opacity:.25;pointer-events:none}.tiles.answer .tile{border-color:#c9d6ef}.feedback{border-radius:14px;flex-direction:column;gap:6px;padding:14px;display:flex}.feedback.ok{background:var(--ok-bg);color:var(--ok)}.feedback.bad{background:var(--bad-bg);color:var(--bad)}.feedback .title{font-size:16px;font-weight:800}.feedback .detail{color:var(--text);font-size:15px}.feedback .why{color:var(--muted);font-size:13px}.record{flex-direction:column;align-items:center;gap:10px;padding:10px 0;display:flex}.mic{background:var(--primary);color:#fff;border:0;border-radius:50%;width:84px;height:84px;font-size:34px;box-shadow:0 8px 24px #1f6feb59}.mic.listening{background:var(--bad);animation:1s infinite pulse}@keyframes pulse{0%{box-shadow:0 0 #cf222e80}to{box-shadow:0 0 0 20px #cf222e00}}.score{font-size:36px;font-weight:900}.score.ok{color:var(--ok)}.score.bad{color:var(--bad)}.score.near{color:var(--primary);font-size:26px}.heard{color:var(--muted);font-size:14px}.missing{color:var(--bad);font-weight:700}.result{text-align:center;padding:24px 16px}.result .big{font-size:56px;font-weight:900}.result .stars{font-size:32px}textarea.input,input.input{border:2px solid 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var(--line);border-radius:10px;display:inline-flex;overflow:hidden}.seg button{background:#fff;border:0;padding:6px 12px;font-size:13px}.seg button.on{background:var(--primary);color:#fff;font-weight:700}.verb-table{border-collapse:collapse;width:100%;font-size:14px}.verb-table td,.verb-table th{border-bottom:1px solid var(--line);text-align:left;padding:6px 4px}.verb-table th{color:var(--muted);font-size:12px;font-weight:600}.kbd{color:var(--muted);font-size:12px}