:root{--bg: #ffffff;--soft: #f4f6f9;--ink: #1c2a3b;--muted: #5d6b7c;--line: #d8dfe8;--blue: #2c5aa0;--blue-soft: #eaf0f9;--red: #c42f28;--red-soft: #fcebe9;--ok: #2c7a4b;--ok-soft: #e6f3eb;--gold: #b07d10;--serif: "Noto Serif TC", "Songti TC", "PMingLiU", serif;--sans: "Noto Sans TC", "PingFang TC", "Microsoft JhengHei", system-ui, sans-serif}@media(prefers-color-scheme:dark){:root{--bg: #12171e;--soft: #19202a;--ink: #e3e9f0;--muted: #97a4b4;--line: #2e3946;--blue: #8fb2ec;--blue-soft: #1d2a3e;--red: #ff7b6f;--red-soft: #3a1f1e;--ok: #62c78f;--ok-soft: #173022;--gold: #e3b54a}}*,*:before,*:after{box-sizing:border-box}html{-webkit-text-size-adjust:100%}body{margin:0;background:var(--bg);color:var(--ink);font-family:var(--sans);font-size:16px;line-height:1.6;overflow-wrap:anywhere}h1,h2,h3{font-family:var(--serif);line-height:1.35;margin:.4em 0}h1{font-size:1.4rem}h2{font-size:1.15rem}a{color:var(--blue)}button{font:inherit;color:inherit}ul,ol{padding-left:1.2em}.muted{color:var(--muted)}.small{font-size:.85rem}.gold{color:var(--gold)}.error{color:var(--red)}.row{display:flex;align-items:center;gap:8px}.row.wrap{flex-wrap:wrap}.row.between{justify-content:space-between}.row.end{justify-content:flex-end}.topbar{display:flex;align-items:center;justify-content:space-between;gap:8px;padding:10px 16px;border-bottom:1px solid var(--line);position:sticky;top:0;background:var(--bg);z-index:5}.topbar a{text-decoration:none;color:var(--muted)}.topbar nav{display:flex;gap:14px}.topbar a.active{color:var(--ink);font-weight:600}.topbar .brand{font-family:var(--serif);font-weight:700;color:var(--ink)}.page{max-width:720px;margin:0 auto;padding:12px 16px 48px}.btn{display:inline-flex;align-items:center;justify-content:center;min-height:44px;padding:8px 16px;border:1px solid var(--line);border-radius:10px;background:var(--bg);color:var(--ink);text-decoration:none;cursor:pointer}.btn.primary{background:var(--blue);border-color:var(--blue);color:var(--bg)}.btn:disabled{opacity:.45;cursor:default}.small-btn{min-height:36px;padding:4px 12px;font-size:.9rem}.link-btn{background:none;border:none;padding:10px 0;color:var(--muted);text-decoration:underline;cursor:pointer;min-height:44px}.link-btn:disabled{opacity:.45}.card{background:var(--soft);border:1px solid var(--line);border-radius:12px;padding:14px 16px}.backdrop{position:fixed;top:0;right:0;bottom:0;left:0;background:#00000059;display:flex;align-items:center;justify-content:center;padding:16px;z-index:20}.dialog{background:var(--bg);border:1px solid var(--line);border-radius:12px;padding:16px;width:100%;max-width:360px}.banner{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:10px;background:var(--blue-soft);border:1px solid var(--line);border-radius:12px;padding:12px 14px;margin-bottom:12px}.total-stars{margin:4px 0 12px}.subject{margin-bottom:20px}.subject-head{display:flex;flex-wrap:wrap;align-items:baseline;gap:8px 12px;border-bottom:2px solid var(--ink);padding-bottom:6px}.subject-head h2{margin:0}.subject-head .btn{margin-left:auto}.units{list-style:none;padding:0;margin:0}.unit{border-bottom:1px solid var(--line);padding:10px 0}.unit-main{display:flex;gap:8px;text-decoration:none;color:var(--ink);min-height:32px;align-items:baseline}.unit-main .title{font-weight:600}.code{color:var(--muted);font-size:.85rem;white-space:nowrap}.unit-meta{display:flex;flex-wrap:wrap;align-items:center;gap:6px 10px;font-size:.85rem;margin:4px 0}.unit-actions{display:flex;flex-wrap:wrap;gap:8px;align-items:center;margin-top:6px}.tag{border:1px solid var(--line);border-radius:999px;padding:0 8px;color:var(--muted)}.stars{color:var(--line);letter-spacing:1px}.star.on{color:var(--gold)}.status{color:var(--muted)}.status-cleared{color:var(--ok);font-weight:600}.status-lesson_done{color:var(--blue)}.lesson .card{margin:12px 0}.rich p,.rich ul{margin:.4em 0}.rich .key{color:var(--red)}.mnemonic{border:1px dashed var(--red);background:var(--red-soft);border-radius:8px;padding:8px 12px}.dots{display:flex;justify-content:center;gap:6px;margin:8px 0}.dot{width:28px;height:28px;border-radius:50%;border:none;background:none;padding:0;cursor:pointer;position:relative}.dot:after{content:"";position:absolute;top:9px;right:9px;bottom:9px;left:9px;border-radius:50%;background:var(--line)}.dot.current:after{background:var(--blue)}.finish{margin-top:16px;display:grid;gap:12px}.progress{height:6px;background:var(--soft);border-radius:3px;overflow:hidden;margin:6px 0 10px}.progress>div{height:100%;background:var(--blue)}.qdots{display:flex;flex-wrap:wrap;gap:6px;margin-bottom:8px}.qdot{width:36px;height:36px;border-radius:50%;border:1px solid var(--line);background:var(--bg);font-size:.85rem;cursor:pointer}.qdot.answered{background:var(--blue-soft);border-color:var(--blue);color:var(--blue)}.qdot.current{outline:2px solid var(--ink);outline-offset:1px}.stem{font-family:var(--serif);font-size:1.15rem;font-weight:600;margin:12px 0}.options{display:grid;gap:10px}.option{display:flex;gap:10px;align-items:flex-start;text-align:left;width:100%;min-height:48px;padding:10px 12px;border:1px solid var(--line);border-radius:10px;background:var(--bg);cursor:pointer}.option.selected{border-color:var(--blue);background:var(--blue-soft)}.option:disabled{cursor:default}.letter{font-weight:700;color:var(--muted);min-width:1.2em}.option.selected .letter{color:var(--blue)}.nav-buttons{margin-top:16px}.score-box{text-align:center;padding:8px 0 16px;border-bottom:1px solid var(--line)}.score{font-family:var(--serif);font-size:3.5rem;font-weight:700;color:var(--red);line-height:1.1}.unit-label{font-size:1.2rem;margin-left:4px}.verdict{font-weight:700;margin-top:4px}.verdict.pass{color:var(--ok)}.verdict.fail{color:var(--red)}.score-line{margin:6px 0 0;color:var(--muted)}.review{list-style:none;padding:0}.review-item{border-bottom:1px solid var(--line);padding:12px 0}.mark{font-size:1.5rem;color:var(--red);font-weight:700;line-height:1}.unanswered{color:var(--red);font-weight:600;margin:4px 0}.review-options{list-style:none;padding:0;margin:8px 0;display:grid;gap:6px}.review-option{display:flex;flex-wrap:wrap;gap:8px;align-items:center;padding:4px 6px}.review-option .opt-text{flex:1 1 60%}.review-option.answer .letter{color:var(--red);border:2px solid var(--red);border-radius:50%;width:1.8em;height:1.8em;display:inline-flex;align-items:center;justify-content:center}.review-option.chosen-wrong .opt-text{text-decoration:line-through;text-decoration-color:var(--red)}.review-option.chosen-wrong .letter{color:var(--red)}.tag-ok,.tag-wrong{font-size:.75rem;border-radius:999px;padding:0 8px;white-space:nowrap}.tag-ok{background:var(--ok-soft);color:var(--ok)}.tag-wrong{background:var(--red-soft);color:var(--red)}.explanation{background:var(--soft);border-radius:8px;padding:8px 12px}.explanation p{margin:4px 0 0}.history{list-style:none;padding:0}.history-row{display:flex;justify-content:space-between;align-items:center;gap:12px;padding:12px 0;border-bottom:1px solid var(--line);text-decoration:none;color:var(--ink)}.history-main{display:grid}.history-score{font-family:var(--serif);font-weight:700;white-space:nowrap}.history-score.pass{color:var(--ok)}.history-score.fail{color:var(--red)}.persist,.backup{margin:12px 0}.persist h2,.backup h2{margin:0 0 6px;font-size:1.05rem}.ok{color:var(--ok)}.file-input{position:absolute;width:1px;height:1px;opacity:0;overflow:hidden;pointer-events:none}label.btn{position:relative}.import-preview{background:var(--bg);border:1px solid var(--line);border-radius:10px;padding:8px 12px;margin-top:10px}.import-preview p{margin:4px 0}