.container{width:100%}.flex{display:flex}.h-full{height:100%}.items-center{align-items:center}.justify-center{justify-content:center}:root{--bg-primary:#0f0f1a;--bg-secondary:#1a1a2e;--bg-card:#16213e;--bg-card-back:#1a1a2e;--text-primary:#eaeaea;--text-secondary:#a0a0a0;--accent:#7c3aed;--accent-light:#a78bfa;--again:#ef4444;--hard:#f59e0b;--good:#22c55e;--easy:#3b82f6;--node-parent:#8b5cf6;--node-current:#06b6d4;--node-child:#10b981;--node-sibling:#6b7280;--border-radius:16px;--shadow:0 10px 40px #0006}body{background:linear-gradient(135deg,var(--bg-primary)0%,var(--bg-secondary)100%);color:var(--text-primary);min-height:100vh;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,sans-serif}.container{flex-direction:column;gap:24px;width:100%;max-width:600px;min-height:100vh;margin:0 auto;padding:20px;display:flex}.stats-bar{background:var(--bg-secondary);border-radius:var(--border-radius);box-shadow:var(--shadow);justify-content:center;gap:40px;padding:16px 24px;display:flex}.stat{flex-direction:column;align-items:center;gap:4px;display:flex}.stat-value{color:var(--accent-light);font-size:28px;font-weight:700}.stat-label{color:var(--text-secondary);text-transform:uppercase;letter-spacing:1px;font-size:12px}.flashcard-area{perspective:1000px;flex:1;justify-content:center;align-items:center;display:flex}.flashcard{aspect-ratio:3/4;width:100%;max-height:500px;transform-style:preserve-3d;cursor:pointer;transition:transform .6s cubic-bezier(.4,0,.2,1);position:relative}.flashcard.flipped{transform:rotateY(180deg)}.card-face{backface-visibility:hidden;border-radius:var(--border-radius);width:100%;height:100%;box-shadow:var(--shadow);position:absolute;overflow:hidden}.card-front{background:linear-gradient(145deg,var(--bg-card)0%,#1e3a5f 100%);justify-content:center;align-items:center;display:flex}.card-back{background:var(--bg-card-back);overflow-y:auto;transform:rotateY(180deg)}.card-content{flex-direction:column;height:100%;padding:24px;display:flex}.card-title{text-align:center;margin-bottom:20px;font-size:24px;font-weight:600;line-height:1.4}.card-tags{flex-wrap:wrap;justify-content:center;gap:8px;margin-bottom:24px;display:flex}.tag{background:var(--accent);color:#fff;border-radius:20px;padding:6px 12px;font-size:12px;font-weight:500}.card-hint{color:var(--text-secondary);text-align:center;margin-top:auto;font-size:14px}.card-title-small{color:var(--accent-light);border-bottom:1px solid #ffffff1a;margin-bottom:16px;padding-bottom:12px;font-size:16px;font-weight:600}.brain-graph-container{background:#0000004d;border:1px solid #ffffff1a;border-radius:12px;flex-direction:column;align-items:center;margin-bottom:16px;padding:12px;display:flex}.brain-graph-legend{justify-content:center;gap:12px;margin-bottom:8px;font-size:10px;display:flex}.legend-item{color:#fff;border-radius:10px;align-items:center;gap:4px;padding:2px 8px;font-weight:500;display:flex}.legend-item:before{content:"";border-radius:50%;width:8px;height:8px}.legend-item.parent:before{background:#8b5cf6}.legend-item.current:before{background:#06b6d4;box-shadow:0 0 6px #06b6d4}.legend-item.child:before{background:#10b981}.legend-item.jump:before{background:#f59e0b}.brain-graph-placeholder{height:120px;color:var(--text-secondary);justify-content:center;align-items:center;font-size:14px;display:flex}.outline-view{background:#0003;border-radius:12px;flex-direction:column;align-items:center;gap:8px;margin-bottom:16px;padding:16px;display:flex}.outline-section{flex-direction:column;align-items:center;gap:6px;display:flex}.outline-label{color:var(--text-secondary);text-transform:uppercase;letter-spacing:1px;font-size:10px}.outline-nodes{flex-wrap:wrap;justify-content:center;gap:8px;display:flex}.outline-connector{background:linear-gradient(to bottom,var(--node-parent),var(--node-current));width:2px;height:12px}.outline-children .outline-connector{background:linear-gradient(to bottom,var(--node-current),var(--node-child))}.outline-node{text-overflow:ellipsis;white-space:nowrap;text-align:center;border-radius:8px;max-width:120px;padding:6px 12px;font-size:11px;overflow:hidden}.parent-node{background:var(--node-parent);color:#fff}.current-node{background:var(--node-current);color:#fff;font-weight:600;box-shadow:0 0 20px #06b6d466}.child-node{background:var(--node-child);color:#fff}.sibling-node{background:var(--node-sibling);color:#fff}.sibling-node:empty,.outline-node:empty{display:none}.card-note{scrollbar-width:thin;scrollbar-color:var(--bg-card)transparent;flex:1;margin-bottom:12px;overflow-y:auto}.note-label{color:var(--text-secondary);margin-bottom:8px;font-size:12px}.note-content{color:var(--text-primary);white-space:pre-wrap;font-size:14px;line-height:1.6}.note-content:empty:after{content:"（无笔记）";color:var(--text-secondary);font-style:italic}.card-meta{border-top:1px solid #ffffff1a;justify-content:center;gap:16px;padding-top:12px;display:flex}.meta-item{color:var(--text-secondary);font-size:12px}.rating-buttons{grid-template-columns:repeat(4,1fr);gap:12px;display:grid}.rating-btn{cursor:pointer;border:none;border-radius:12px;flex-direction:column;align-items:center;gap:4px;padding:16px 8px;font-family:inherit;transition:all .2s;display:flex}.rating-btn:hover{transform:translateY(-2px);box-shadow:0 6px 20px #0000004d}.rating-btn:active{transform:translateY(0)}.rating-again{background:var(--again);color:#fff}.rating-hard{background:var(--hard);color:#fff}.rating-good{background:var(--good);color:#fff}.rating-easy{background:var(--easy);color:#fff}.rating-name{font-size:14px;font-weight:600}.rating-interval{opacity:.8;font-size:12px}.rating-buttons:disabled .rating-btn,.rating-btn:disabled{opacity:.5;cursor:not-allowed;box-shadow:none;transform:none}.completion-message{text-align:center;flex-direction:column;justify-content:center;align-items:center;height:100%;padding:40px;display:flex}.completion-icon{margin-bottom:20px;font-size:64px;animation:1s infinite bounce}@keyframes bounce{0%,to{transform:translateY(0)}50%{transform:translateY(-10px)}}.completion-message h2{color:var(--good);margin-bottom:12px;font-size:28px}.completion-message p{color:var(--text-secondary)}@media (max-width:480px){.container{padding:12px}.stats-bar{gap:24px;padding:12px 16px}.stat-value{font-size:24px}.card-title{font-size:20px}.rating-btn{padding:12px 4px}}