:root{--bg: #f4f6fb;--card: #ffffff;--ink: #1e2a3b;--ink-2: #5b6b83;--ink-3: #93a1b8;--line: #e6ebf3;--primary: #5b5bd6;--primary-2: #7c6ee8;--primary-soft: #eef0fd;--green: #22a06b;--green-soft: #e6f6ee;--amber: #d9822b;--amber-soft: #fdf3e4;--red: #d64550;--red-soft: #fdecee;--blue: #2d7de0;--blue-soft: #e8f1fd;--radius: 16px;--shadow: 0 1px 2px rgba(30, 42, 59, .05), 0 8px 24px rgba(30, 42, 59, .06);--font: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", -apple-system, "Segoe UI", Roboto, sans-serif}*{box-sizing:border-box;margin:0;padding:0}html,body,#app{height:100%}body{font-family:var(--font);color:var(--ink);background:var(--bg);font-size:15px;line-height:1.6;-webkit-font-smoothing:antialiased}a{color:var(--primary);text-decoration:none}button{font-family:inherit}.shell{display:flex;min-height:100vh}.sidebar{width:232px;flex-shrink:0;background:linear-gradient(180deg,#2f2b6c,#453c9e);color:#fff;padding:20px 14px;display:flex;flex-direction:column;gap:6px;position:sticky;top:0;height:100vh;overflow-y:auto}.brand{display:flex;align-items:center;gap:10px;padding:6px 10px 18px;font-size:17px;font-weight:700}.brand .logo{width:36px;height:36px;border-radius:10px;background:#fff;color:#453c9e;display:grid;place-items:center;font-size:20px;box-shadow:0 4px 12px #0003}.nav-item{display:flex;align-items:center;gap:10px;padding:10px 12px;border-radius:12px;color:#ffffffd1;font-size:14.5px;cursor:pointer;border:none;background:none;width:100%;text-align:left;transition:background .15s}.nav-item:hover{background:#ffffff1a;color:#fff}.nav-item.active{background:#ffffff2e;color:#fff;font-weight:600}.nav-item .ic{font-size:18px;width:22px;text-align:center}.sidebar-foot{margin-top:auto;padding:10px 12px;border-top:1px solid rgba(255,255,255,.15);font-size:12.5px;color:#ffffffa6}.main{flex:1;min-width:0;display:flex;flex-direction:column}.topbar{display:flex;align-items:center;gap:14px;padding:14px 28px;background:var(--card);border-bottom:1px solid var(--line);position:sticky;top:0;z-index:20}.topbar .grow{flex:1}.pill{display:inline-flex;align-items:center;gap:6px;background:var(--primary-soft);color:var(--primary);border-radius:999px;padding:5px 14px;font-weight:600;font-size:13.5px}.pill.green{background:var(--green-soft);color:var(--green)}.pill.amber{background:var(--amber-soft);color:var(--amber)}.content{padding:26px 28px 60px;max-width:1160px;width:100%;margin:0 auto}.content.bare{max-width:none;padding:0;margin:0}.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);padding:20px}.h1{font-size:24px;font-weight:800}.h2{font-size:18px;font-weight:700;margin:0 0 4px}.sub{color:var(--ink-2);font-size:13.5px}.grid{display:grid;gap:16px}.cols-2{grid-template-columns:repeat(2,1fr)}.cols-3{grid-template-columns:repeat(3,1fr)}.cols-4{grid-template-columns:repeat(4,1fr)}@media (max-width: 900px){.cols-3,.cols-4{grid-template-columns:repeat(2,1fr)}.cols-2{grid-template-columns:1fr}}.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;border:none;border-radius:12px;padding:10px 18px;font-size:14.5px;font-weight:600;cursor:pointer;transition:transform .08s,box-shadow .15s,background .15s;background:var(--primary);color:#fff}.btn:hover{filter:brightness(1.06)}.btn:active{transform:scale(.97)}.btn:disabled{opacity:.5;cursor:not-allowed}.btn.secondary{background:var(--primary-soft);color:var(--primary)}.btn.ghost{background:transparent;color:var(--ink-2);border:1px solid var(--line)}.btn.danger{background:var(--red-soft);color:var(--red)}.btn.green{background:var(--green);color:#fff}.btn.amber{background:var(--amber);color:#fff}.btn.lg{padding:13px 26px;font-size:16px;border-radius:14px}.btn.sm{padding:6px 12px;font-size:13px;border-radius:9px}.field{margin-bottom:14px}.field 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.num{font-size:22px;font-weight:800;color:var(--primary)}.level-card.locked .num{color:var(--ink-3)}.level-card.cleared .num{color:var(--green)}.level-card .name{font-size:13.5px;font-weight:600;margin:6px 0 2px;line-height:1.4}.level-card .meta{font-size:12px;color:var(--ink-3)}.flash-wrap{perspective:1200px;max-width:560px;margin:0 auto}.flash{position:relative;min-height:280px;border-radius:20px;background:var(--card);border:1px solid var(--line);box-shadow:var(--shadow);display:grid;place-items:center;padding:28px;cursor:pointer;transform-style:preserve-3d;transition:transform .28s ease;text-align:center}.flash.flipped{transform:rotateY(180deg)}.flash .face{backface-visibility:hidden;-webkit-backface-visibility:hidden;padding:12px}.flash .back{position:absolute;top:0;right:0;bottom:0;left:0;transform:rotateY(180deg);display:grid;place-items:center}.word-big{font-size:42px;font-weight:800;letter-spacing:.5px}.phon{color:var(--ink-2);margin-top:6px;font-size:17px}.flip-hint{color:var(--ink-3);font-size:12.5px;margin-top:10px}.meaning-big{font-size:24px;font-weight:700;color:var(--primary)}.pos-tag{display:inline-block;background:var(--primary-soft);color:var(--primary);border-radius:6px;padding:2px 8px;font-size:12.5px;margin-top:8px}.example-line{margin-top:14px;color:var(--ink-2);font-style:italic}.quiz-option{display:flex;align-items:center;gap:10px;width:100%;border:1.5px solid var(--line);background:#fff;border-radius:12px;padding:12px 15px;font-size:14.5px;cursor:pointer;margin-bottom:10px;text-align:left;transition:border-color .12s,background .12s}.quiz-option:hover:not(:disabled){border-color:var(--primary-2)}.quiz-option.picked{border-color:var(--primary);background:var(--primary-soft)}.quiz-option.right{border-color:var(--green);background:var(--green-soft)}.quiz-option.wrong{border-color:var(--red);background:var(--red-soft)}.cloze-text{font-size:17px;line-height:2.4;letter-spacing:1px}.cloze-text .blank{color:var(--primary);font-weight:700}.cloze-input{width:4.2em;max-width:120px;border:none;border-bottom:2px solid var(--primary-2);background:transparent;font-size:17px;text-align:center;color:var(--primary);font-weight:700;outline:none;padding:0 4px}.cloze-input::placeholder{color:var(--ink-3);font-weight:400;font-size:13px}.cloze-input.correct{border-bottom-color:var(--green);color:var(--green)}.cloze-input.wrong{border-bottom-color:var(--red);color:var(--red)}.cloze-wrap{display:inline-flex;align-items:center;gap:3px;vertical-align:bottom}.hint-btn{border:none;background:var(--amber-soft);color:var(--amber);border-radius:6px;font-size:11px;width:18px;height:18px;line-height:1;padding:0;cursor:pointer;flex-shrink:0}.hint-btn:hover{background:var(--amber);color:#fff}.cloze-answer{display:inline-block;margin-left:6px;padding:0 8px;border-radius:6px;background:var(--green-soft);color:var(--green);font-size:12.5px;font-weight:700;line-height:1.7;white-space:nowrap;vertical-align:middle}.text-block{font-size:16.5px;line-height:2.2;letter-spacing:.4px}.text-block .sent{cursor:default;border-radius:6px;padding:0 2px;transition:background .15s}.text-block .sent.hl{background:var(--amber-soft)}.text-block .sent.done{color:var(--ink-3)}.trans-block{color:var(--ink-2);font-size:14.5px;line-height:2}.word-inline{cursor:pointer;border-bottom:1px dotted var(--primary-2)}.recite-card{max-width:620px;margin:0 auto;min-height:170px;background:var(--card);border:1.5px dashed var(--primary-2);border-radius:18px;display:grid;place-items:center;padding:34px 30px;cursor:pointer;text-align:center;transition:transform .15s,box-shadow .15s,border-color .15s}.recite-card:hover{transform:translateY(-3px);box-shadow:var(--shadow);border-color:var(--primary)}.recite-card.revealed{cursor:default;border-style:solid;border-color:var(--line)}.recite-mask{font-size:19px;letter-spacing:6px;color:var(--ink-3);line-height:2.2;font-weight:600}.progress{height:8px;background:#eef1f6;border-radius:999px;overflow:hidden}.progress>i{display:block;height:100%;background:linear-gradient(90deg,var(--primary),var(--primary-2));border-radius:999px;transition:width 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toast-in{0%{transform:translate(30px);opacity:0}to{transform:none;opacity:1}}.login-wrap{position:fixed;top:0;right:0;bottom:0;left:0;z-index:40;display:grid;place-items:center;background:linear-gradient(135deg,#35307a,#5b5bd6 55%,#7c6ee8);padding:20px;overflow-y:auto}.login-card{width:100%;max-width:400px;background:#fff;border-radius:22px;padding:34px 30px;box-shadow:0 24px 60px #14103c59}.login-title{font-size:22px;font-weight:800;text-align:center;margin-bottom:4px}.login-sub{text-align:center;color:var(--ink-2);font-size:13.5px;margin-bottom:24px}.flex{display:flex;gap:12px;align-items:center}.flex.between{justify-content:space-between}.wrap{flex-wrap:wrap}.mt{margin-top:16px}.mt2{margin-top:26px}.mb{margin-bottom:14px}.text-muted{color:var(--ink-2)}.small{font-size:12.5px}.divider{height:1px;background:var(--line);margin:18px 0}.center{text-align:center}.empty{color:var(--ink-3);text-align:center;padding:40px 0;font-size:14px}.chip{display:inline-block;background:#f1f3f9;border-radius:8px;padding:2px 9px;font-size:12.5px;color:var(--ink-2);margin-right:6px;margin-bottom:6px}.play{font-size:40px}.big-emoji{font-size:46px}