:root{--bg-primary: #ffffff;--bg-secondary: #f8f9fb;--bg-tertiary: #eef0f4;--bg-hover: #e8eaef;--bg-active: #dde0e8;--text-primary: #1a1d23;--text-secondary: #5f6577;--text-muted: #8b90a0;--accent: #4f46e5;--accent-hover: #4338ca;--accent-light: #eef2ff;--border: #e2e5ed;--border-light: #eef0f4;--success: #16a34a;--success-light: #dcfce7;--warning: #d97706;--warning-light: #fef3c7;--error: #dc2626;--error-light: #fee2e2;--shadow-sm: 0 1px 2px rgba(0, 0, 0, .05);--shadow-md: 0 4px 12px rgba(0, 0, 0, .08);--shadow-lg: 0 8px 24px rgba(0, 0, 0, .12);--radius-sm: 6px;--radius-md: 10px;--radius-lg: 14px;--header-height: 56px}@media(prefers-color-scheme:dark){:root{--bg-primary: #0f1117;--bg-secondary: #161922;--bg-tertiary: #1e2230;--bg-hover: #252a38;--bg-active: #2d3345;--text-primary: #e8eaf0;--text-secondary: #9ca3b8;--text-muted: #6b7290;--accent: #818cf8;--accent-hover: #6366f1;--accent-light: #1e1b4b;--border: #2a2f40;--border-light: #222738;--success: #4ade80;--success-light: #052e16;--warning: #fbbf24;--warning-light: #451a03;--error: #f87171;--error-light: #450a0a;--shadow-sm: 0 1px 2px rgba(0, 0, 0, .3);--shadow-md: 0 4px 12px rgba(0, 0, 0, .4);--shadow-lg: 0 8px 24px rgba(0, 0, 0, .5)}}[data-theme=light]{--bg-primary: #ffffff;--bg-secondary: #f8f9fb;--bg-tertiary: #eef0f4;--bg-hover: #e8eaef;--bg-active: #dde0e8;--text-primary: #1a1d23;--text-secondary: #5f6577;--text-muted: #8b90a0;--accent: #4f46e5;--accent-hover: #4338ca;--accent-light: #eef2ff;--border: #e2e5ed;--border-light: #eef0f4;--success: #16a34a;--success-light: #dcfce7;--warning: #d97706;--warning-light: #fef3c7;--error: #dc2626;--error-light: #fee2e2;--shadow-sm: 0 1px 2px rgba(0, 0, 0, .05);--shadow-md: 0 4px 12px rgba(0, 0, 0, .08);--shadow-lg: 0 8px 24px rgba(0, 0, 0, .12)}[data-theme=dark]{--bg-primary: #0f1117;--bg-secondary: #161922;--bg-tertiary: #1e2230;--bg-hover: #252a38;--bg-active: #2d3345;--text-primary: #e8eaf0;--text-secondary: #9ca3b8;--text-muted: #6b7290;--accent: #818cf8;--accent-hover: #6366f1;--accent-light: #1e1b4b;--border: #2a2f40;--border-light: #222738;--success: #4ade80;--success-light: #052e16;--warning: #fbbf24;--warning-light: #451a03;--error: #f87171;--error-light: #450a0a;--shadow-sm: 0 1px 2px rgba(0, 0, 0, .3);--shadow-md: 0 4px 12px rgba(0, 0, 0, .4);--shadow-lg: 0 8px 24px rgba(0, 0, 0, .5)}*,*:before,*:after{box-sizing:border-box;margin:0;padding:0}html{font-size:15px;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica 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.logo{font-size:1.3rem}.header-actions{margin-left:auto;display:flex;align-items:center;gap:8px}.breadcrumbs{display:flex;align-items:center;gap:4px;font-size:.85rem;color:var(--text-muted);white-space:nowrap;overflow:hidden;text-overflow:ellipsis;flex:1;min-width:0}.breadcrumb-item{color:var(--text-secondary);cursor:pointer;padding:2px 6px;border-radius:var(--radius-sm);transition:background .15s;white-space:nowrap}.breadcrumb-item:hover{background:var(--bg-hover);color:var(--text-primary);text-decoration:none}.breadcrumb-item.active{color:var(--text-primary);font-weight:600;cursor:default}.breadcrumb-item.active:hover{background:transparent}.breadcrumb-sep{color:var(--text-muted);font-size:.75rem;flex-shrink:0}.theme-toggle{width:36px;height:36px;border-radius:var(--radius-sm);display:flex;align-items:center;justify-content:center;font-size:1.1rem;transition:background .15s}.theme-toggle:hover{background:var(--bg-hover)}.tag{display:inline-block;padding:2px 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.15s;font-size:.88rem}.quiz-answer:hover{background:var(--bg-hover);border-color:var(--accent)}.quiz-answer.selected{border-color:var(--accent);background:var(--accent-light)}.quiz-answer.correct{border-color:var(--success);background:var(--success-light)}.quiz-answer.incorrect{border-color:var(--error);background:var(--error-light)}.quiz-radio{width:18px;height:18px;border-radius:50%;border:2px solid var(--border);flex-shrink:0;display:flex;align-items:center;justify-content:center;transition:all .15s}.quiz-answer.selected .quiz-radio{border-color:var(--accent);background:var(--accent)}.quiz-answer.selected .quiz-radio:after{content:"";width:6px;height:6px;border-radius:50%;background:#fff}.quiz-answer-text{color:var(--text-primary);flex:1}.quiz-result{margin-top:10px;padding:10px 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16px;background:var(--error-light);color:var(--error);border-radius:var(--radius-sm);font-size:.85rem;margin-bottom:16px;display:flex;align-items:center;gap:8px}::-webkit-scrollbar{width:6px}::-webkit-scrollbar-track{background:transparent}::-webkit-scrollbar-thumb{background:var(--border);border-radius:999px}::-webkit-scrollbar-thumb:hover{background:var(--text-muted)}@media(max-width:768px){.info-grid,.course-grid{grid-template-columns:1fr}.card{padding:16px}}@media(max-width:400px){.header{padding:0 12px}.header-title{font-size:.95rem}.course-grid{gap:12px}.card{padding:14px}.course-card-title{font-size:.95rem}}@media(max-width:320px){.header{padding:0 8px}.header-title{font-size:.85rem}.course-grid{gap:8px}.card{padding:12px}.course-card-title{font-size:.9rem}.info-grid{grid-template-columns:1fr}}.login-screen{display:flex;align-items:center;justify-content:center;min-height:100vh;background:var(--bg-secondary)}.login-card{display:flex;flex-direction:column;align-items:center;gap:16px;padding:40px;background:var(--bg-primary);border:1px solid var(--border);border-radius:var(--radius-lg);box-shadow:var(--shadow-lg);width:100%;max-width:360px}.login-card h1{font-size:1.5rem;font-weight:700;color:var(--text-primary)}.login-subtitle{font-size:.85rem;color:var(--text-muted);margin-bottom:8px}.login-card form{width:100%;display:flex;flex-direction:column;gap:12px}.login-input{width:100%;padding:10px 14px;border:1px solid var(--border);border-radius:var(--radius-sm);background:var(--bg-secondary);color:var(--text-primary);font-size:.9rem;outline:none;transition:border-color .15s}.login-input:focus{border-color:var(--accent)}.login-input::placeholder{color:var(--text-muted)}.login-btn{width:100%;justify-content:center;padding:10px 16px}.login-error{font-size:.8rem;color:var(--error);text-align:center}