:root{--primary:#4b88a2;--accent:#ffba08;--success:#5b8266;--bg-light:#e8eff3;--bg-accent:#fff6de;--bg-green:#eaf1ec;--text:#012a36;--text-muted:#5a7380;--border:#c8d5dc}*{box-sizing:border-box;margin:0;padding:0}body{color:var(--text);-webkit-font-smoothing:antialiased;background:#fff;font-family:Georgia,Times New Roman,serif;line-height:1.7}.article{max-width:760px;margin:0 auto;padding:3rem 1.5rem 6rem}.article h1{margin-bottom:.3rem;font-size:2.2rem;font-weight:700;line-height:1.2}.subtitle{color:var(--text-muted);margin-bottom:2.5rem;font-size:1.1rem;font-style:italic}.section{margin-bottom:3rem}.section h2{border-bottom:2px solid var(--primary);margin-bottom:1rem;padding-bottom:.3rem;font-size:1.5rem;font-weight:700}.section p{margin-bottom:1rem;font-size:1.05rem}code{background:var(--bg-light);border-radius:3px;padding:.15em .4em;font-family:Menlo,Consolas,monospace;font-size:.9em}pre{border:1px solid var(--border);background:#f7f9fa;border-radius:8px;margin-bottom:1rem;padding:1rem 1.2rem;font-size:.88rem;line-height:1.6;overflow-x:auto}pre code{background:0 0;padding:0}.box{border-left:4px solid var(--border);background:#f7f9fa;border-radius:8px;margin-bottom:1.2rem;padding:1rem 1.2rem}.box.definition{border-left-color:var(--primary);background:var(--bg-light)}.box.key-idea{border-left-color:var(--accent);background:var(--bg-accent)}.box.remark{border-left-color:var(--success);background:var(--bg-green)}.box p{margin-bottom:.5rem}.box p:last-child{margin-bottom:0}.box-title{text-transform:uppercase;letter-spacing:.05em;margin-bottom:.5rem;font-size:.9rem;font-weight:700}.box.definition .box-title{color:var(--primary)}.box.key-idea .box-title{color:var(--accent)}.box.remark .box-title{color:var(--success)}.diagram{margin:1.5rem 0}.diagram svg{width:100%;height:auto;display:block}.caption{color:var(--text-muted);text-align:center;margin-top:.5rem;font-size:.9rem;font-style:italic}.step-controls{flex-wrap:wrap;align-items:center;gap:8px;margin-top:12px;display:flex}.step-btn{border:1.5px solid var(--primary);color:var(--primary);cursor:pointer;background:#fff;border-radius:6px;padding:6px 14px;font-family:inherit;font-size:.85rem;transition:background .15s,color .15s}.step-btn:hover{background:var(--bg-light)}.step-btn.active{background:var(--primary);color:#fff}.run-controls{flex-wrap:wrap;align-items:center;gap:10px;margin-top:12px;display:flex}.run-btn{background:var(--primary);color:#fff;cursor:pointer;border:none;border-radius:6px;padding:8px 20px;font-family:inherit;font-size:.9rem;font-weight:600;transition:background .15s}.run-btn:hover{background:#3a7390}.run-btn:disabled{cursor:default;background:#8da8b5}.speed-btn{border:1px solid var(--border);color:var(--text);cursor:pointer;background:#fff;border-radius:4px;padding:4px 12px;font-family:inherit;font-size:.8rem}.speed-btn.active{background:var(--text);color:#fff;border-color:var(--text)}.run-status{color:var(--text-muted);font-family:Menlo,monospace;font-size:.85rem}.katex-display{margin:1rem 0;overflow-x:auto}.diagram-annotation{color:var(--text-muted);text-align:center;min-height:1.4em;margin-top:.3rem;font-size:.85rem}.branch-group{background:var(--bg-light);border:1px solid var(--border);border-radius:6px;align-items:center;gap:6px;padding:6px 10px;display:flex}.branch-label{color:var(--text-muted);white-space:nowrap;margin-right:4px;font-size:.78rem}.step-btn:disabled{opacity:.4;cursor:not-allowed}.step-btn:disabled:hover{background:#fff}