:root{--lightningcss-light:initial;--lightningcss-dark: ;color-scheme:light;--grad-primary:linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #3b82f6 100%);--primary:#6366f1;--primary-strong:#4f46e5;--accent:#14b8a6;--success:#10b981;--danger:#f43f5e;--warning:#f59e0b;--bg:#f4f6fb;--surface:#fff;--surface-2:#f8fafc;--surface-3:#eef1f6;--border:#e4e8f0;--border-strong:#d3d9e6;--text:#1f2430;--text-2:#4b5563;--text-muted:#8a94a6;--text-invert:#fff;--code-bg:#f6f8fa;--console-bg:#0f172a;--console-text:#dbe3f0;--console-muted:#8a94a6;--console-error:#fda4af;--console-warn:#fcd34d;--sidebar-w:264px;--radius-sm:6px;--radius:10px;--radius-lg:14px;--shadow-sm:0 1px 2px #1018280a;--shadow:0 6px 20px #10182814;--shadow-lg:0 12px 32px #10182824;--font:-apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;--mono:"JetBrains Mono", "Fira Code", Consolas, "Courier New", monospace}[data-theme=dark]{--lightningcss-light: ;--lightningcss-dark:initial;color-scheme:dark;--primary:#818cf8;--primary-strong:#a5b4fc;--accent:#2dd4bf;--bg:#0b0f1a;--surface:#141a28;--surface-2:#1a2132;--surface-3:#232c40;--border:#222b3d;--border-strong:#2f3a52;--text:#e6eaf2;--text-2:#aab3c4;--text-muted:#6b7688;--text-invert:#0b0f1a;--code-bg:#1a2132;--console-bg:#05070d;--console-text:#cdd6e6;--console-muted:#6b7688;--console-error:#fda4af;--console-warn:#fcd34d;--shadow-sm:0 1px 2px #0006;--shadow:0 6px 20px #0006;--shadow-lg:0 12px 32px #0000008c}*{box-sizing:border-box}html,body{height:100%;margin:0}body{background:var(--bg);color:var(--text);font-family:var(--font);-webkit-font-smoothing:antialiased;transition:background .2s,color .2s}.hidden{display:none!important}#app{height:100vh;height:100dvh;display:flex;overflow:hidden}#sidebar{width:var(--sidebar-w);min-width:var(--sidebar-w);background:var(--surface);border-right:1px solid var(--border);z-index:20;flex-direction:column;transition:margin-left .2s,background .2s;display:flex}#sidebar.collapsed{margin-left:calc(-1 * var(--sidebar-w))}.brand{background:var(--grad-primary);align-items:center;gap:10px;padding:18px;display:flex;position:relative;overflow:hidden}.brand:after{content:"";pointer-events:none;background:radial-gradient(120px 60px at 85% 0,#ffffff40,#0000 70%);position:absolute;top:0;bottom:0;left:0;right:0}.brand-icon{filter:drop-shadow(0 2px 3px #0003);font-size:24px}.brand-name{color:#fff;letter-spacing:.02em;font-size:17px;font-weight:800}#lesson-nav{flex:1;padding:10px;overflow-y:auto}.chapter-title{color:var(--text-muted);text-transform:uppercase;letter-spacing:.08em;align-items:center;gap:6px;padding:14px 10px 6px;font-size:11px;font-weight:700;display:flex}.chapter-title:before{content:"";background:var(--grad-primary);border-radius:50%;width:4px;height:4px}.nav-item{border-radius:var(--radius-sm);color:var(--text-2);cursor:pointer;align-items:center;gap:10px;padding:9px 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.3s}#main{flex-direction:column;flex:1;min-width:0;display:flex}#topbar{background:var(--surface);border-bottom:1px solid var(--border);align-items:center;gap:12px;height:56px;padding:0 16px;transition:background .2s;display:flex}#topbar h1{white-space:nowrap;text-overflow:ellipsis;flex:1;margin:0;font-size:17px;font-weight:700;overflow:hidden}.icon-btn{cursor:pointer;width:34px;height:34px;color:var(--text-2);border-radius:var(--radius-sm);background:0 0;border:none;justify-content:center;align-items:center;font-size:17px;transition:background .15s,color .15s,transform .15s;display:inline-flex}.icon-btn:hover{background:var(--surface-3);color:var(--text)}.icon-btn:active{transform:scale(.94)}.topbar-actions{align-items:center;gap:10px;display:flex}#panes{flex:1;min-height:0;display:flex}#splitter{cursor:col-resize;background:var(--border);z-index:10;flex:none;width:5px;transition:background 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var(--primary);background:var(--surface-2);border-radius:0 var(--radius-sm) var(--radius-sm) 0;color:var(--text-2);margin:12px 0;padding:10px 16px}.markdown-body table{border-collapse:collapse;width:100%;margin:12px 0}.markdown-body th,.markdown-body td{border:1px solid var(--border);text-align:left;padding:8px 12px}.markdown-body th{background:var(--surface-2);font-weight:600}.quiz-section{background:var(--surface-2);border:1px solid var(--border);border-radius:var(--radius-lg);box-shadow:var(--shadow-sm);margin-top:36px;padding:20px}.quiz-section h2{align-items:center;gap:8px;margin:0 0 16px;font-size:18px;font-weight:700;display:flex}.quiz-question{margin-bottom:18px}.quiz-prompt{margin:0 0 10px;font-weight:600;line-height:1.6}.quiz-options{flex-direction:column;gap:8px;display:flex}.quiz-option{border:1px solid var(--border);border-radius:var(--radius-sm);cursor:pointer;background:var(--surface);align-items:center;gap:10px;padding:10px 12px;font-size:14px;transition:border-color 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#console,#workspace.console-collapsed #console-splitter{height:0;min-height:0;padding:0;display:none}#workspace.console-collapsed #console-collapse{transform:rotate(-90deg)}.console-line{white-space:pre-wrap;word-break:break-all;line-height:1.55}.console-line.stdout{color:var(--console-text)}.console-line.stderr{color:var(--console-warn)}.console-line.error{color:var(--console-error)}.console-line.info{color:var(--console-muted);font-style:italic}#pyodide-status{color:var(--primary);background:color-mix(in srgb, var(--primary) 10%, var(--surface));border-top:1px solid var(--border);flex:none;padding:7px 14px;font-size:13px}#pyodide-status.error{color:var(--danger);background:color-mix(in srgb, var(--danger) 10%, var(--surface))}.btn{border:1px solid var(--border);background:var(--surface);border-radius:var(--radius-sm);cursor:pointer;color:var(--text-2);align-items:center;gap:6px;padding:7px 14px;font-size:13px;font-weight:500;transition:background .15s,color .15s,border-color .15s,transform .1s,opacity .15s;display:inline-flex}.btn:hover{background:var(--surface-3);color:var(--text)}.btn:active{transform:scale(.97)}.btn.ghost:hover{background:var(--surface-3)}.btn.primary{background:var(--grad-primary);color:#fff;box-shadow:var(--shadow-sm);border-color:#0000;font-weight:600}.btn.primary:hover{filter:brightness(1.05);color:#fff}.btn.primary:disabled{opacity:.65;cursor:not-allowed;filter:none}.btn .spinner{border:2px solid #fff6;border-top-color:#fff;border-radius:50%;width:13px;height:13px;animation:.7s linear infinite spin}@keyframes spin{to{transform:rotate(360deg)}}#sidebar-backdrop{z-index:90;opacity:0;pointer-events:none;background:#00000073;transition:opacity .2s;position:fixed;top:56px;bottom:0;left:0;right:0}#sidebar-backdrop.show{opacity:1;pointer-events:auto}@media (max-width:1050px){:root{--sidebar-w:232px}#panes{flex-direction:column;overflow-y:auto}#splitter{cursor:row-resize;touch-action:none;width:100%;height:10px;display:block}#content{border-bottom:1px solid var(--border);flex:none;min-width:320px;padding:24px}#workspace{flex:none;width:100%;min-width:320px;max-width:none;height:42dvh;min-height:300px}#console-splitter{touch-action:none;display:block}.markdown-body{font-size:14.5px}}@media (max-width:768px){#sidebar{z-index:100;width:min(80vw,300px);min-width:0;box-shadow:var(--shadow-lg);margin-left:0;transition:transform .25s;position:fixed;top:0;bottom:0;left:0;transform:translate(-100%)}#sidebar.open{transform:translate(0)}#sidebar.collapsed{margin-left:0;transform:translate(-100%)}#content{padding:18px 16px}#workspace{height:44dvh}#editor{flex:1}.markdown-body{max-width:none;font-size:15px}#topbar h1{font-size:16px}.nav-item{padding:12px 10px;font-size:15px}.btn{padding:9px 14px}.icon-btn{width:38px;height:38px}.collapse-btn{padding:6px 8px}.markdown-body table{white-space:nowrap;display:block;overflow-x:auto}.markdown-body pre{font-size:12.5px}.quiz-section{padding:14px}}@media (max-width:480px){#content{padding:14px 12px}#workspace{height:46dvh;min-height:260px}.markdown-body h1{font-size:22px}.markdown-body h2{font-size:18px}.workspace-header,.console-header{padding:6px 10px}.workspace-actions .btn{padding:8px 10px;font-size:12.5px}.brand{padding:14px 16px}.brand-icon{font-size:20px}.brand-name{font-size:15px}}