*{box-sizing:border-box}html,body,#app{margin:0;padding:0;height:100%;overflow:hidden;font-family:Segoe UI,PingFang SC,Microsoft YaHei,system-ui,-apple-system,sans-serif;color:#111827;background:#fff}a{color:inherit;text-decoration:none}code{font-family:ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace;font-size:.9em;background:#eef2ff;padding:1px 6px;border-radius:4px}.n-modal.fade-in-scale-up-transition-leave-active,.n-modal.fade-in-scale-up-transition-leave-to,.n-modal.fade-in-scale-up-transition-leave-from{transform:scale(1)!important}.md-body.courseware{color:#303133;line-height:1.75;font-size:14.5px}.md-body.courseware>.cw-enter{animation:cw-fade-up .45s ease both;animation-delay:var(--cw-delay, 0ms)}@keyframes cw-fade-up{0%{opacity:0;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}.md-body h1,.md-body h2,.md-body h3,.md-body h4{margin:1.15em 0 .5em;color:#1f2937;line-height:1.35;font-weight:650}.md-body h1{font-size:22px;letter-spacing:-.02em}.md-body h2{font-size:17px;padding-bottom:6px;border-bottom:1px solid #f1f5f9}.md-body h3{font-size:15px;color:#334155}.md-body h4{font-size:14px;color:#c2410c}.md-body p{margin:.55em 0}.md-body ul,.md-body ol{margin:.5em 0;padding-left:1.35em}.md-body li{margin:.28em 0}.md-body strong{color:#0f172a;font-weight:650}.md-body code{font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:.9em;background:#f1f5f9;color:#c2410c;padding:.1em .35em;border-radius:4px}.cw-table-wrap{overflow-x:auto;margin:14px 0;border-radius:10px;border:1px solid #eef2f7;box-shadow:0 1px 2px #0f172a08}.md-body table{width:100%;border-collapse:collapse;font-size:13.5px;margin:0}.md-body th,.md-body td{border-bottom:1px solid #eef2f7;border-right:1px solid #f8fafc;padding:10px 12px;text-align:left;vertical-align:top}.md-body th{background:linear-gradient(180deg,#fafbfc,#f4f6f8);color:#475569;font-weight:600;white-space:nowrap}.md-body tr:last-child td{border-bottom:none}.md-body tbody tr{transition:background .15s}.md-body tbody tr:hover{background:#fffbfa}.cw-quote,.md-body blockquote{margin:14px 0;padding:12px 16px;border-left:3px solid #e85d4c;background:linear-gradient(90deg,#fdecea,#fff7f5);color:#57534e;border-radius:0 10px 10px 0}.cw-code,.md-body pre.cw-code{background:#0f172a;color:#e2e8f0;padding:14px 16px;border-radius:10px;overflow:auto;font-size:13px;margin:12px 0}.cw-diagram{position:relative;margin:16px 0;padding:16px 12px;background:linear-gradient(180deg,#fafbfc,#fff);border:1px solid #eef2f7;border-radius:12px;overflow-x:auto;text-align:center;box-shadow:0 1px 3px #0f172a0a}.cw-diagram .mermaid,.cw-diagram svg{max-width:100%;height:auto;margin:0 auto}.cw-diagram--zoomable{cursor:zoom-in;transition:border-color .15s ease,box-shadow .15s ease}.cw-diagram--zoomable:hover{border-color:#bfdbfe;box-shadow:0 4px 14px #2563eb1a}.cw-diagram--zoomable:focus-visible{outline:2px solid #3b82f6;outline-offset:2px}.cw-diagram__zoom-hint{position:absolute;top:8px;right:8px;z-index:1;padding:3px 8px;border-radius:999px;background:#0f172ab8;color:#fff;font-size:11px;line-height:1.4;pointer-events:none;opacity:.88;letter-spacing:.02em}.cw-diagram--zoomable:hover .cw-diagram__zoom-hint{background:#2563ebe6}.cw-diagram .mermaid-error{text-align:left;white-space:pre-wrap;color:#b91c1c;font-size:12px;background:#fef2f2;padding:10px;border-radius:8px}.md-body.courseware img.cw-img--zoomable{max-width:100%;height:auto;cursor:zoom-in;border-radius:8px;transition:box-shadow .15s ease}.md-body.courseware img.cw-img--zoomable:hover{box-shadow:0 4px 16px #0f172a1f}.cw-viewer{position:fixed;top:0;right:0;bottom:0;left:0;z-index:4000;display:flex;flex-direction:column;background:#e8edf3;animation:cw-viewer-in .16s ease both;-webkit-user-select:none;user-select:none;touch-action:none}@keyframes cw-viewer-in{0%{opacity:0}to{opacity:1}}.cw-viewer__toolbar{flex:0 0 auto;display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:10px 16px;padding:10px 14px;background:#0f172af5;border-bottom:1px solid rgba(148,163,184,.18);color:#e2e8f0}.cw-viewer__tools,.cw-viewer__zoom{display:flex;flex-wrap:wrap;align-items:center;gap:6px}.cw-viewer__btn{-webkit-appearance:none;-moz-appearance:none;appearance:none;border:1px solid rgba(148,163,184,.28);background:#1e293be6;color:#e2e8f0;border-radius:8px;padding:6px 12px;font-size:13px;line-height:1.2;cursor:pointer;transition:background .12s ease,border-color .12s ease}.cw-viewer__btn:hover{background:#334155f2;border-color:#94a3b873}.cw-viewer__btn.is-active{background:#2563eb;border-color:#3b82f6;color:#fff}.cw-viewer__scale{min-width:64px;font-variant-numeric:tabular-nums;font-family:ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace}.cw-viewer__close{margin-left:4px;background:#ef44442e;border-color:#f8717173}.cw-viewer__close:hover{background:#ef444459}.cw-viewer__divider{width:1px;height:22px;margin:0 4px;background:#94a3b840}.cw-viewer__colors{display:flex;align-items:center;gap:6px}.cw-viewer__swatch{width:22px;height:22px;border-radius:999px;border:2px solid transparent;cursor:pointer;padding:0;box-shadow:inset 0 0 0 1px #ffffff26}.cw-viewer__swatch.is-active{border-color:#fff;box-shadow:0 0 0 2px #3b82f6b3}.cw-viewer__width{display:inline-flex;align-items:center;gap:6px;margin:0 4px;font-size:12px;color:#94a3b8}.cw-viewer__width input{width:88px;accent-color:#3b82f6}.cw-viewer__viewport{--cw-canvas-bg: #e8edf3;--cw-canvas-grid: rgba(100, 116, 139, .22);position:relative;flex:1 1 auto;min-height:0;overflow:hidden;display:flex;align-items:center;justify-content:center;background-color:var(--cw-canvas-bg);background-image:linear-gradient(var(--cw-canvas-grid) 1px,transparent 1px),linear-gradient(90deg,var(--cw-canvas-grid) 1px,transparent 1px);background-size:28px 28px;cursor:grab}.cw-viewer__viewport.is-pan{cursor:grab}.cw-viewer__viewport.is-pan:active{cursor:grabbing}.cw-viewer__viewport.is-pen{cursor:crosshair}.cw-viewer__viewport.is-eraser{cursor:cell}.cw-viewer__world{position:relative;flex:0 0 auto;transform-origin:center center;will-change:transform}.cw-viewer__board{position:relative;box-sizing:border-box;display:flex;align-items:center;justify-content:center;overflow:hidden;border-radius:0;background-color:var(--cw-canvas-bg, #e8edf3);background-image:linear-gradient(var(--cw-canvas-grid, rgba(100, 116, 139, .22)) 1px,transparent 1px),linear-gradient(90deg,var(--cw-canvas-grid, rgba(100, 116, 139, .22)) 1px,transparent 1px);background-size:28px 28px;box-shadow:none}.cw-viewer__content{position:relative;z-index:1;line-height:0;pointer-events:none;display:flex;align-items:center;justify-content:center}.cw-viewer__content svg,.cw-viewer__svg{display:block;max-width:min(1100px,70vw)!important;max-height:min(72vh,820px);width:auto!important;height:auto!important;margin:0 auto;background:#ffffffeb;border-radius:10px;box-shadow:0 0 0 1px #0f172a0f,0 8px 28px #0f172a14;padding:16px 20px;box-sizing:content-box}.cw-viewer__img{display:block;max-width:min(1100px,70vw);max-height:min(72vh,820px);width:auto;height:auto;margin:0 auto;background:#ffffffeb;border-radius:10px;padding:12px;box-sizing:content-box;box-shadow:0 0 0 1px #0f172a0f,0 8px 28px #0f172a14}.cw-viewer__ink{position:absolute;top:0;right:0;bottom:0;left:0;z-index:2;width:100%;height:100%;pointer-events:none;touch-action:none}.cw-viewer__hint{flex:0 0 auto;margin:0;padding:6px 14px 8px;text-align:center;font-size:12px;color:#e2e8f08c;background:#0f172ae6;border-top:1px solid rgba(148,163,184,.12)}@media(max-width:720px){.cw-viewer__toolbar{padding:8px 10px}.cw-viewer__btn{padding:6px 9px;font-size:12px}}.cw-demo{margin:16px 0;overflow:hidden;border:1px solid #e7edf4;border-radius:12px;background:#fbfdff;box-shadow:0 1px 3px #0f172a0a}.cw-demo__caption{padding:8px 14px;border-bottom:1px solid #eef2f7;background:#f4f7fa;color:#475569;font-size:12px;font-weight:650}.cw-demo code{font-size:11px}.cw-demo--html{padding:12px}.cw-demo__header,.cw-demo__footer,.cw-demo__main{border:1px solid #dce7ee;border-radius:8px}.cw-demo__header{display:flex;align-items:center;flex-wrap:wrap;gap:8px 12px;padding:9px 10px;background:#eff8ff}.cw-demo__header strong{color:#0f3a57;font-size:14px}.cw-demo__header nav{display:flex;align-items:center;gap:8px;margin-left:auto}.cw-demo__header a{color:#2563eb;font-size:12px}.cw-demo__main{margin:8px 0;padding:12px;background:#fff}.cw-demo__main h4{margin:5px 0;color:#1e293b;font-size:15px}.cw-demo__main p{margin:4px 0 10px;color:#64748b;font-size:13px}.cw-demo__main button{padding:6px 10px;border:0;border-radius:6px;background:#cbd5e1;color:#475569}.cw-demo__footer{padding:7px 10px;background:#f8fafc;color:#64748b;font-size:12px}.cw-demo--css,.cw-demo--js{padding:12px}.cw-demo--css .cw-demo__caption,.cw-demo--js .cw-demo__caption{margin:-12px -12px 12px}.cw-demo__css-row{display:flex;gap:12px}.cw-demo__css-card{flex:1 1 0;min-width:0;display:flex;flex-direction:column;gap:6px;padding:11px;border:1px solid #dce7ee;border-radius:9px;background:#fff;color:#475569;font-size:12px;transition:transform .2s ease,border-color .2s ease,box-shadow .2s ease}.cw-demo__css-card:hover{transform:translateY(-3px);border-color:#e85d4c;box-shadow:0 7px 14px #e85d4c21}.cw-demo__hint{margin:10px 0 0;color:#64748b;font-size:12px}.cw-demo__js-stage{display:flex;align-items:center;gap:14px}.cw-demo__action{min-height:34px;padding:6px 13px;border:1px solid #c2410c;border-radius:7px;background:#fff7ed;color:#9a3412;cursor:pointer;font-size:13px;font-weight:650;transition:transform .15s ease,background .15s ease}.cw-demo__action:hover{background:#ffedd5}.cw-demo__action:active{transform:translateY(1px) scale(.98)}.cw-demo__action:focus-visible{outline:2px solid #e85d4c;outline-offset:2px}.cw-demo__counter{display:flex;align-items:baseline;gap:7px;color:#64748b;font-size:12px}.cw-demo__counter strong{color:#c2410c;font-size:25px;line-height:1}.cw-quiz{margin:14px 0;padding:12px;border:1px solid #dce7ee;border-radius:12px;background:#fbfdff}.cw-quiz__caption{margin:-12px -12px 10px;padding:8px 12px;border-bottom:1px solid #e7edf4;background:#f4f7fa;color:#475569;font-size:12px;font-weight:650}.cw-quiz__question{margin:0 0 10px;color:#1e293b;font-size:14px;font-weight:600}.cw-quiz__options{display:grid;gap:7px}.cw-quiz__options button{width:100%;padding:8px 10px;border:1px solid #dce7ee;border-radius:7px;background:#fff;color:#475569;cursor:pointer;font:inherit;font-size:13px;text-align:left;transition:border-color .15s ease,background .15s ease}.cw-quiz__options button:hover{border-color:#e85d4c;background:#fff7f5}.cw-quiz__options button:focus-visible{outline:2px solid #e85d4c;outline-offset:2px}.cw-quiz__options button.is-correct{border-color:#86efac;background:#f0fdf4;color:#166534}.cw-quiz__options button.is-wrong{border-color:#fecaca;background:#fef2f2;color:#b91c1c}.cw-quiz__feedback{min-height:1.6em;margin:10px 0 0;color:#64748b;font-size:12px}.cw-quiz-bank{margin:16px 0;overflow:hidden;border:1px solid #dce7ee;border-radius:12px;background:#fbfdff}.cw-quiz-bank__head{display:flex;justify-content:space-between;gap:12px;padding:11px 14px;border-bottom:1px solid #e7edf4;background:#f4f7fa}.cw-quiz-bank__head strong{color:#334155;font-size:14px}.cw-quiz-bank__head span{color:#64748b;font-size:12px}.cw-quiz-bank__tabs{display:flex;gap:6px;padding:10px 12px 0;overflow-x:auto}.cw-quiz-bank__tabs button{flex:1 0 108px;min-height:34px;padding:6px 9px;border:1px solid #dce7ee;border-radius:7px 7px 0 0;background:#fff;color:#64748b;cursor:pointer;font:inherit;font-size:13px;font-weight:600}.cw-quiz-bank__tabs button span{margin-left:5px;color:#94a3b8;font-size:11px;font-weight:400}.cw-quiz-bank__tabs button[aria-selected=true]{border-color:#e85d4c;background:#fff7f5;color:#c2410c}.cw-quiz-bank__panel{padding:12px}.cw-quiz-bank__summary{margin-bottom:10px;padding:8px 10px;border-radius:7px;background:#eff8ff;color:#0f3a57;font-size:12px;font-weight:600}.cw-quiz-bank__question{padding:12px 0;border-bottom:1px solid #eef2f7}.cw-quiz-bank__question:last-child{border-bottom:0}.cw-quiz-bank__question>p{display:flex;align-items:flex-start;gap:8px;margin:0 0 8px;color:#334155;font-size:14px;font-weight:600}.cw-quiz-bank__question>p span{flex:0 0 20px;height:20px;border-radius:50%;background:#f1f5f9;color:#64748b;font-size:11px;line-height:20px;text-align:center}.cw-quiz-bank__options{display:grid;gap:6px}.cw-quiz-bank__options button{width:100%;padding:8px 10px;border:1px solid #dce7ee;border-radius:7px;background:#fff;color:#475569;cursor:pointer;font:inherit;font-size:13px;text-align:left;transition:border-color .15s ease,background .15s ease}.cw-quiz-bank__options button:hover{border-color:#e85d4c;background:#fff7f5}.cw-quiz-bank__options button:focus-visible,.cw-quiz-bank__tabs button:focus-visible{outline:2px solid #e85d4c;outline-offset:2px}.cw-quiz-bank__options button.is-correct{border-color:#86efac;background:#f0fdf4;color:#166534}.cw-quiz-bank__options button.is-wrong{border-color:#fecaca;background:#fef2f2;color:#b91c1c}.cw-quiz-bank__feedback{min-height:1.5em;margin-top:7px;color:#64748b;font-size:12px}@media(max-width:620px){.cw-demo__css-row{flex-direction:column}.cw-quiz-bank__head{display:block}.cw-quiz-bank__head span{display:block;margin-top:3px}.cw-demo__header nav{width:100%;margin-left:0}}@media(prefers-reduced-motion:reduce){.cw-demo__css-card,.cw-demo__action,.cw-quiz__options button{transition:none}}.cw-card{margin:14px 0;border-radius:12px;border:1px solid #eef2f7;overflow:hidden;box-shadow:0 1px 2px #0f172a08}.cw-card__label{font-size:12px;font-weight:700;letter-spacing:.04em;padding:8px 14px;border-bottom:1px solid rgba(0,0,0,.04)}.cw-card__body{padding:10px 14px 12px;font-size:14px}.cw-card__body p{margin:.35em 0}.cw-card__body ul{margin:.35em 0;padding-left:1.2em}.cw-card--goal{border-color:#bfdbfe;background:#f8fbff}.cw-card--goal .cw-card__label{background:#eff6ff;color:#1d4ed8}.cw-card--tip{border-color:#fcd9d3;background:#fffbfa}.cw-card--tip .cw-card__label{background:#fdecea;color:#c2410c}.cw-card--warn{border-color:#fde68a;background:#fffbeb}.cw-card--warn .cw-card__label{background:#fef3c7;color:#b45309}.cw-card--danger{border-color:#fecaca;background:#fef2f2}.cw-card--danger .cw-card__label{background:#fee2e2;color:#b91c1c}.cw-card--ok{border-color:#bbf7d0;background:#f0fdf4}.cw-card--ok .cw-card__label{background:#dcfce7;color:#15803d}