*{box-sizing:border-box;margin:0;padding:0}:root{--bg:#0f1729;--bg2:#0a0e17;--surface:#1a2235;--surface2:#1e2d50;--text:#e9e8f0;--text2:#94a3b8;--accent:#0959C8;--accent2:#3b82f6;--border:#2a3a55;--success:#10b981;--warning:#f59e0b;--danger:#ef4444;--glass:rgba(255,255,255,0.04);--glass-border:rgba(255,255,255,0.08);--radius:10px;--shadow:0 4px 20px rgba(0,0,0,0.3);--font:"Inter",sans-serif;--transition:0.3s ease}[data-theme="light"]{--bg:#f8fafc;--bg2:#eef2f6;--surface:#fff;--surface2:#e2e8f0;--text:#0f172a;--text2:#475569;--accent:#2563eb;--accent2:#3b82f6;--border:#cbd5e1;--glass:rgba(0,0,0,0.03);--glass-border:rgba(0,0,0,0.08);--shadow:0 4px 20px rgba(0,0,0,0.08)}body{font-family:"Inter",sans-serif;background:var(--bg);color:var(--text);min-height:100vh;line-height:1.5}.diagram-container{max-width:900px;margin:0 auto;padding:16px}.diagram-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:8px}.diagram-title{font-size:20px;font-weight:700;color:var(--accent2)}.diagram-desc{font-size:13px;color:var(--text2);margin-bottom:12px}.icon-btn,.ctrl-btn{min-height:48px;min-width:48px;padding:10px 18px;border:1px solid var(--border);background:var(--surface);color:var(--text);border-radius:var(--radius);cursor:pointer;font-family:"Inter",sans-serif;font-size:13px;font-weight:500}.icon-btn:hover,.ctrl-btn:hover{background:var(--surface2);border-color:var(--accent2)}.icon-btn:focus-visible,.ctrl-btn:focus-visible{outline:2px solid var(--accent2)}.primary-btn{background:var(--accent);color:#fff}.toolbar{display:flex;flex-wrap:wrap;gap:8px;align-items:center;margin-bottom:12px;padding:10px 14px;background:var(--glass);border:1px solid var(--glass-border);border-radius:var(--radius)}.speed-control{display:flex;align-items:center;gap:8px;flex:1;min-width:140px}.speed-label{font-size:12px;color:var(--text2)}.speed-slider{flex:1;accent-color:var(--accent2)}.visual-container{background:var(--bg2);border:1px solid var(--border);border-radius:var(--radius);min-height:300px;margin-bottom:12px}.diagram-svg{width:100%;height:auto;display:block}.node-group{cursor:pointer}.node-group:hover{opacity:0.85}.node-bg{transition:all 0.3s ease}.info-panel{position:fixed;top:50%;left:50%;transform:translate(-50%,-50%);width:90%;max-width:460px;max-height:80vh;overflow-y:auto;background:var(--surface);border:1px solid var(--border);border-radius:14px;padding:24px;z-index:100;display:none}.info-panel[aria-hidden="false"]{display:block}.info-close{position:absolute;top:12px;right:12px;width:40px;height:40px;border:none;background:var(--glass);color:var(--text2);border-radius:50%;cursor:pointer}.info-title{font-size:17px;font-weight:700;color:var(--accent2);margin-bottom:12px}.info-content{font-size:13px;color:var(--text2)}.challenge-section{margin-top:16px}.section-title{font-size:16px;font-weight:700;color:var(--accent2);margin-bottom:10px}.challenge-container{display:flex;flex-direction:column;gap:10px}.challenge-question{padding:14px;background:var(--glass);border:1px solid var(--glass-border);border-radius:var(--radius)}.challenge-q-text{font-size:13px;font-weight:600;color:var(--text);margin-bottom:8px}.challenge-options{display:flex;flex-direction:column;gap:6px}.challenge-option{display:flex;align-items:center;gap:8px;padding:8px 12px;border:1px solid var(--border);border-radius:6px;cursor:pointer;font-size:12px;color:var(--text2);min-height:44px}.challenge-option:hover{border-color:var(--accent2)}.challenge-option input[type="radio"]{accent-color:var(--accent2)}.challenge-option.selected{background:rgba(9,89,200,0.1);border-color:var(--accent2)}.challenge-option.correct{background:rgba(16,185,129,0.1);border-color:var(--success);color:var(--success)}.challenge-option.wrong{background:rgba(239,68,68,0.1);border-color:var(--danger);color:var(--danger)}.challenge-submit{min-height:48px;padding:10px 24px;background:var(--accent);color:#fff;border:none;border-radius:var(--radius);cursor:pointer;font-family:"Inter",sans-serif;font-size:14px;font-weight:600;margin-top:8px}.challenge-submit:hover{background:var(--accent2)}.challenge-result{padding:16px;background:var(--glass);border:1px solid var(--glass-border);border-radius:var(--radius);margin-top:10px;font-size:13px;text-align:center}.completion-overlay{position:fixed;top:0;left:0;width:100%;height:100%;background:rgba(0,0,0,0.7);display:flex;align-items:center;justify-content:center;z-index:200;display:none}.completion-card{background:var(--surface);border:1px solid var(--border);border-radius:16px;padding:32px;max-width:400px;width:90%;text-align:center}.completion-title{font-size:22px;font-weight:700;color:var(--accent2);margin-bottom:10px}.completion-score{font-size:15px;color:var(--text2);margin-bottom:12px}.completion-concepts{font-size:12px;color:var(--text2);margin-bottom:16px}.skeleton{position:relative;overflow:hidden;padding:16px;max-width:900px;margin:0 auto}.skeleton-shimmer{position:absolute;top:0;left:-100%;width:100%;height:100%;background:linear-gradient(90deg,transparent,rgba(255,255,255,0.04),transparent);animation:shimmer 1.8s infinite}.skeleton-header{height:28px;width:200px;background:var(--surface);border-radius:6px;margin-bottom:12px}.skeleton-visual{height:300px;background:var(--surface);border-radius:var(--radius);margin-bottom:12px}.skeleton-controls{height:48px;background:var(--surface);border-radius:var(--radius);margin-bottom:12px}@keyframes shimmer{0%{left:-100%}100%{left:100%}}.error-boundary{background:rgba(239,68,68,0.1);border:1px solid var(--danger);border-radius:var(--radius);padding:16px;margin-bottom:12px;font-size:13px;color:var(--danger)}@media(max-width:768px){.diagram-container{padding:10px}}@media(max-width:480px){.diagram-container{padding:6px}.info-panel{width:95%;padding:16px}}