:root{color-scheme:light;--bg: #f8fafc;--surface: #ffffff;--surface-muted: #f1f5f9;--line: #d9e2ea;--line-strong: #bac7d4;--text: #172026;--muted: #617282;--teal: #0f766e;--teal-strong: #115e59;--teal-soft: #e3f5f2;--amber: #b7791f;--amber-soft: #fff7e6;--green: #16794c;--green-soft: #e7f7ef;--red: #b42318;--red-soft: #fff0ed;--shadow: 0 12px 34px rgba(15, 23, 42, .08);font-family:Inter,Noto Sans TC,Microsoft JhengHei,system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif;font-size:16px;line-height:1.5;background:var(--bg);color:var(--text)}*{box-sizing:border-box}body{margin:0;min-width:320px;min-height:100vh;background:linear-gradient(180deg,#e3f5f2cc,#f8fafc00 280px),var(--bg)}button,input,select,textarea{font:inherit}button{cursor:pointer}button:disabled{cursor:not-allowed;opacity:.48}a{color:inherit}.app-shell{min-height:100vh;padding-bottom:0}.topbar{position:sticky;top:0;z-index:20;display:flex;align-items:center;justify-content:space-between;gap:18px;min-height:68px;padding:12px 24px;border-bottom:1px solid rgba(217,226,234,.9);background:#ffffffeb;-webkit-backdrop-filter:blur(12px);backdrop-filter:blur(12px)}.brand,.topbar-controls,.source-status,.question-meta,.answer-bar,.question-nav,.memory-header,.memory-item,.visual-warning{display:flex;align-items:center}.brand{gap:12px;min-width:0}.brand-mark{display:grid;width:42px;height:42px;place-items:center;border-radius:8px;background:var(--teal);color:#fff;box-shadow:0 6px 16px #0f766e38}.brand p{margin:0;font-size:1rem;font-weight:760}.brand span{display:block;color:var(--muted);font-size:.78rem}.topbar-controls{justify-content:flex-end;gap:10px}.source-status{gap:7px;min-height:36px;padding:0 12px;border:1px solid var(--line);border-radius:8px;background:var(--surface);color:var(--muted);font-size:.84rem;white-space:nowrap}.source-status svg{color:var(--teal)}.source-status strong{color:var(--text)}.icon-button{display:grid;width:36px;height:36px;place-items:center;border:1px solid var(--line);border-radius:8px;background:var(--surface);color:var(--muted)}.workspace{display:grid;grid-template-columns:244px minmax(0,1fr) 306px;gap:16px;width:min(1440px,calc(100% - 32px));margin:16px auto 24px}.sidebar,.question-panel,.memory-panel,.empty-panel,.filter-panel,.command-row{border:1px solid var(--line);border-radius:8px;background:#fffffff0;box-shadow:var(--shadow)}.sidebar,.memory-panel{align-self:start;position:sticky;top:84px;padding:14px}.mode-list{display:grid;gap:6px}.mode-item{display:flex;align-items:center;gap:10px;width:100%;min-height:40px;padding:0 10px;border:1px solid transparent;border-radius:8px;background:transparent;color:var(--muted);text-align:left;font-size:.92rem;font-weight:650}.mode-item.active,.mode-item:hover{border-color:var(--teal-soft);background:var(--teal-soft);color:var(--teal-strong)}.stat-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:8px;margin:14px 0}.metric{min-height:70px;padding:11px;border:1px solid var(--line);border-radius:8px;background:var(--surface)}.metric strong{display:block;font-size:1.25rem;line-height:1.1}.metric span{color:var(--muted);font-size:.76rem}.filter-panel{display:grid;gap:10px;padding:12px;box-shadow:none}.filter-panel label{display:grid;gap:5px;color:var(--muted);font-size:.76rem;font-weight:650}.filter-panel select,.search-box input{width:100%;min-height:36px;border:1px solid var(--line);border-radius:8px;background:var(--surface);color:var(--text)}.filter-panel select{padding:0 10px}.question-column{display:grid;gap:12px;min-width:0}.command-row{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:12px;min-height:58px;padding:10px;box-shadow:none}.search-box{position:relative;display:flex;align-items:center}.search-box svg{position:absolute;left:12px;color:var(--muted)}.search-box input{padding:0 12px 0 38px;outline:none}.search-box input:focus{border-color:var(--teal);box-shadow:0 0 0 3px #0f766e1f}.question-count{display:grid;min-width:86px;place-items:center;border:1px solid var(--line);border-radius:8px;background:var(--surface-muted)}.question-count span{font-weight:760;line-height:1}.question-count small{color:var(--muted);font-size:.72rem}.question-panel{padding:18px}.question-meta{justify-content:space-between;gap:14px;color:var(--muted);font-size:.86rem}.question-meta>div{display:flex;flex-wrap:wrap;gap:8px}.source-chip{padding:2px 8px;border-radius:999px;background:var(--teal-soft);color:var(--teal-strong);font-weight:760}.bookmark{display:inline-flex;align-items:center;gap:6px;min-height:34px;padding:0 10px;border:1px solid var(--line);border-radius:8px;background:var(--surface);color:var(--muted)}.bookmark.active{border-color:#f3d394;background:var(--amber-soft);color:var(--amber)}.progress-line{height:5px;margin:16px 0 22px;overflow:hidden;border-radius:999px;background:var(--surface-muted)}.progress-line span{display:block;height:100%;border-radius:inherit;background:var(--teal)}.question-content h1{margin:0 0 18px;font-size:clamp(1.08rem,1.45vw,1.38rem);font-weight:760;line-height:1.56;letter-spacing:0}.visual-warning{gap:8px;margin-bottom:14px;padding:10px 12px;border:1px solid #f1d28e;border-radius:8px;background:var(--amber-soft);color:var(--amber);font-size:.88rem}.options{display:grid;gap:10px}.option{display:grid;grid-template-columns:38px minmax(0,1fr);gap:10px;align-items:start;width:100%;min-height:58px;padding:12px;border:1px solid var(--line);border-radius:8px;background:var(--surface);color:var(--text);text-align:left}.option:hover,.option.selected{border-color:var(--teal);background:var(--teal-soft)}.option strong{display:grid;width:34px;height:34px;place-items:center;border-radius:8px;background:var(--surface-muted);color:var(--teal-strong)}.option span{min-width:0;line-height:1.58}.option.correct{border-color:#91d7b2;background:var(--green-soft)}.option.correct strong{background:var(--green);color:#fff}.option.wrong{border-color:#f0b4a9;background:var(--red-soft)}.option.wrong strong{background:var(--red);color:#fff}.answer-bar{justify-content:space-between;gap:12px;margin-top:18px;padding-top:14px;border-top:1px solid var(--line)}.confidence-group{display:inline-grid;grid-template-columns:repeat(3,1fr);gap:4px;padding:4px;border:1px solid var(--line);border-radius:8px;background:var(--surface-muted)}.confidence-group button{min-width:42px;min-height:32px;border:0;border-radius:6px;background:transparent;color:var(--muted);font-size:.86rem;font-weight:760}.confidence-group button.active{background:var(--surface);color:var(--teal-strong);box-shadow:0 1px 4px #0f172a14}.primary-action{min-height:40px;padding:0 18px;border:0;border-radius:8px;background:var(--teal);color:#fff;font-weight:760}.result{display:flex;align-items:center;gap:8px;margin-top:12px;padding:10px 12px;border-radius:8px;font-size:.9rem;font-weight:650}.result.correct{background:var(--green-soft);color:var(--green)}.result.wrong{background:var(--red-soft);color:var(--red)}.question-nav{justify-content:space-between;gap:12px;margin-top:16px;color:var(--muted)}.question-nav button{display:inline-flex;align-items:center;gap:6px;min-height:38px;padding:0 12px;border:1px solid var(--line);border-radius:8px;background:var(--surface);color:var(--text)}.question-nav span{font-size:.9rem;font-weight:760}.memory-panel{display:grid;gap:12px;box-shadow:none}.memory-header{gap:10px}.memory-header svg{color:var(--teal)}.memory-header h2,.confusion-box h3{margin:0;font-size:1rem}.memory-header p{margin:1px 0 0;color:var(--muted);font-size:.8rem}.memory-list{display:grid;gap:8px}.memory-item{display:grid;grid-template-columns:18px 1fr auto;gap:8px;min-height:42px;padding:0 10px;border:1px solid var(--line);border-radius:8px;background:var(--surface);color:var(--muted);font-size:.82rem}.memory-item svg{color:var(--teal)}.memory-item strong{color:var(--text);font-size:.8rem}.confusion-box{padding:12px;border:1px solid var(--line);border-radius:8px;background:var(--surface-muted)}.confusion-box p{margin:7px 0 0;color:var(--muted);font-size:.88rem}.note-box{display:grid;gap:7px;color:var(--muted);font-size:.82rem;font-weight:700}.note-box textarea{min-height:136px;resize:vertical;padding:10px;border:1px solid var(--line);border-radius:8px;outline:none;color:var(--text)}.note-box textarea:focus{border-color:var(--teal);box-shadow:0 0 0 3px #0f766e1f}.source-link{display:grid;min-height:40px;place-items:center;border:1px solid var(--line);border-radius:8px;background:var(--surface);color:var(--teal-strong);font-size:.88rem;font-weight:760;text-decoration:none}.empty-screen,.empty-panel{display:grid;place-items:center;text-align:center}.empty-screen{min-height:100vh;padding:24px}.empty-screen svg{width:42px;height:42px;color:var(--teal)}.empty-screen h1,.empty-panel h2{margin:12px 0 4px}.empty-screen p,.empty-panel p{margin:0;color:var(--muted)}.empty-panel{min-height:420px;padding:24px}.empty-panel svg{color:var(--muted)}.pulse{animation:pulse 1.4s ease-in-out infinite}.mobile-bottom{display:none}@keyframes pulse{0%,to{opacity:.45;transform:scale(.98)}50%{opacity:1;transform:scale(1)}}@media(max-width:1120px){.workspace{grid-template-columns:210px minmax(0,1fr)}.memory-panel{grid-column:2;position:static}}@media(max-width:840px){.app-shell{padding-bottom:74px}.topbar{min-height:62px;padding:10px 12px}.brand span,.source-status span{display:none}.workspace{display:grid;grid-template-columns:minmax(0,1fr);width:min(100% - 18px,620px);margin-top:10px}.memory-panel{grid-column:auto;position:static}.sidebar,.mode-list{display:none}.stat-grid{grid-template-columns:repeat(4,minmax(0,1fr));margin:0 0 10px}.metric{min-height:56px;padding:8px}.metric strong{font-size:1rem}.metric span{font-size:.68rem}.filter-panel,.command-row{grid-template-columns:1fr}.question-count{display:none}.question-panel{padding:14px}.question-meta{align-items:flex-start}.question-content h1{font-size:1.08rem}.answer-bar{align-items:stretch;flex-direction:column}.confidence-group,.primary-action{width:100%}.mobile-bottom{position:fixed;right:10px;bottom:10px;left:10px;z-index:30;display:grid;grid-template-columns:repeat(4,1fr);gap:4px;padding:6px;border:1px solid var(--line);border-radius:8px;background:#fffffff5;box-shadow:0 12px 34px #0f172a24;-webkit-backdrop-filter:blur(12px);backdrop-filter:blur(12px)}.mobile-bottom button{display:grid;gap:2px;min-height:48px;place-items:center;border:0;border-radius:6px;background:transparent;color:var(--muted);font-size:.66rem;font-weight:760}.mobile-bottom button.active{background:var(--teal-soft);color:var(--teal-strong)}}@media(max-width:520px){.topbar-controls{gap:6px}.brand-mark{width:38px;height:38px}.source-status{min-height:34px;padding:0 9px}.stat-grid{grid-template-columns:repeat(2,1fr)}.option{grid-template-columns:34px minmax(0,1fr);padding:10px}.option strong{width:30px;height:30px}}