:root{--bg-primary: #0a0a0f;--bg-secondary: #12121a;--bg-card: #1a1a24;--bg-card-hover: #22222e;--bg-input: #16161f;--text-primary: #f0f0f5;--text-secondary: #a0a0b0;--text-muted: #6b6b7b;--accent-primary: #6366f1;--accent-primary-hover: #818cf8;--accent-secondary: #22d3ee;--accent-gradient: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #a855f7 100%);--border-color: #2a2a3a;--border-focus: #6366f1;--success: #10b981;--error: #ef4444;--warning: #f59e0b;--shadow-sm: 0 2px 8px rgba(0, 0, 0, .3);--shadow-md: 0 8px 24px rgba(0, 0, 0, .4);--shadow-lg: 0 16px 48px rgba(0, 0, 0, .5);--shadow-glow: 0 0 40px rgba(99, 102, 241, .15);--radius-sm: 8px;--radius-md: 12px;--radius-lg: 16px;--radius-xl: 24px;--transition-fast: .15s ease;--transition-normal: .25s ease;--transition-slow: .4s ease}*{box-sizing:border-box}body{margin:0;font-family:Inter,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif;background:var(--bg-primary);color:var(--text-primary);line-height:1.6;min-height:100vh}body:before{content:"";position:fixed;inset:0;background:radial-gradient(ellipse at 20% 20%,rgba(99,102,241,.08) 0%,transparent 50%),radial-gradient(ellipse at 80% 80%,rgba(139,92,246,.06) 0%,transparent 50%),radial-gradient(ellipse at 50% 50%,rgba(168,85,247,.04) 0%,transparent 70%);pointer-events:none;z-index:-1}.centered{min-height:100vh;display:flex;align-items:center;justify-content:center;padding:20px}.container{text-align:center;background:var(--bg-card);padding:48px 56px;border-radius:var(--radius-xl);border:1px solid var(--border-color);box-shadow:var(--shadow-lg),var(--shadow-glow);max-width:500px;width:100%;-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);animation:fadeIn .5s ease}@keyframes fadeIn{0%{opacity:0;transform:translateY(10px)}to{opacity:1;transform:translateY(0)}}h1{font-size:2rem;font-weight:700;margin:0 0 8px;background:var(--accent-gradient);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text;letter-spacing:-.02em}p{font-size:1rem;color:var(--text-secondary);margin:0 0 28px}.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:14px 28px;font-size:15px;font-weight:600;text-decoration:none;border-radius:var(--radius-md);border:none;cursor:pointer;transition:all var(--transition-normal);position:relative;overflow:hidden}.btn:before{content:"";position:absolute;top:0;left:-100%;width:100%;height:100%;background:linear-gradient(90deg,transparent,rgba(255,255,255,.1),transparent);transition:left var(--transition-slow)}.btn:hover:before{left:100%}.btn:hover{transform:translateY(-2px);box-shadow:var(--shadow-md)}.btn:active{transform:translateY(0)}.btn-primary{background:var(--accent-gradient);color:#fff;box-shadow:0 4px 16px #6366f14d}.btn-primary:hover{box-shadow:0 6px 24px #6366f166}.btn-secondary{background:var(--bg-secondary);color:var(--text-primary);border:1px solid var(--border-color)}.btn-secondary:hover{background:var(--bg-card-hover);border-color:var(--accent-primary)}.btn:disabled{opacity:.6;cursor:not-allowed;transform:none}.cta{display:inline-flex;align-items:center;gap:8px;text-decoration:none;background:var(--accent-gradient);color:#fff;padding:16px 32px;border-radius:var(--radius-md);font-weight:600;font-size:16px;box-shadow:0 4px 20px #6366f159;transition:all var(--transition-normal)}.cta:hover{transform:translateY(-2px) scale(1.02);box-shadow:0 8px 30px #6366f173;color:#fff}.button-group{margin-top:32px;display:flex;gap:16px;justify-content:center;flex-wrap:wrap}.upload-form{display:flex;flex-direction:column;align-items:center;gap:20px;margin-top:28px}.upload-form input[type=email],.upload-form input[type=password],.upload-form input[type=text]{width:100%;max-width:360px;padding:14px 18px;font-size:15px;color:var(--text-primary);background:var(--bg-input);border:1px solid var(--border-color);border-radius:var(--radius-md);transition:all var(--transition-fast)}.upload-form input::placeholder{color:var(--text-muted)}.upload-form input:hover{border-color:#3a3a4a}.upload-form input:focus{outline:none;border-color:var(--border-focus);box-shadow:0 0 0 3px #6366f126,var(--shadow-sm);background:var(--bg-secondary)}.upload-form label{font-size:14px;font-weight:600;color:var(--text-secondary)}.file-name{font-size:14px;color:var(--text-muted);padding:8px 16px;background:var(--bg-secondary);border-radius:var(--radius-sm);border:1px dashed var(--border-color)}.preview-container{width:100%;max-width:400px;max-height:200px;overflow-y:auto;background:var(--bg-secondary);border:1px solid var(--border-color);border-radius:var(--radius-md);padding:16px;text-align:left;color:var(--text-secondary)}.preview-container h3{margin:0 0 12px;font-size:14px;font-weight:600;color:var(--text-primary);text-transform:uppercase;letter-spacing:.05em}.preview-container pre{white-space:pre-wrap;font-family:JetBrains Mono,Fira Code,monospace;font-size:13px;line-height:1.5;margin:0;color:var(--text-secondary)}.preview-container::-webkit-scrollbar{width:6px}.preview-container::-webkit-scrollbar-track{background:transparent}.preview-container::-webkit-scrollbar-thumb{background:var(--border-color);border-radius:3px}.preview-container::-webkit-scrollbar-thumb:hover{background:#3a3a4a}.spinner{width:18px;height:18px;border:2px solid rgba(255,255,255,.2);border-top:2px solid white;border-radius:50%;display:inline-block;animation:spin .7s linear infinite;margin-left:8px}@keyframes spin{to{transform:rotate(360deg)}}.loading-container{display:flex;flex-direction:column;align-items:center;gap:16px}.loading-container .spinner{width:32px;height:32px;border-width:3px;margin:0}.question-block{margin-bottom:28px;padding:20px 24px;background:var(--bg-secondary);border-radius:var(--radius-md);border:1px solid var(--border-color);text-align:left;transition:all var(--transition-fast)}.question-block:hover{border-color:#3a3a4a;background:var(--bg-card-hover)}.question-block p{margin:0 0 16px;font-size:15px;font-weight:500;color:var(--text-primary)}.question-block label{display:flex;align-items:center;padding:10px 14px;margin-bottom:8px;background:var(--bg-input);border-radius:var(--radius-sm);cursor:pointer;transition:all var(--transition-fast);border:1px solid transparent;color:var(--text-secondary)}.question-block label:hover{background:var(--bg-card);border-color:var(--border-color);color:var(--text-primary)}.question-block input[type=radio]{appearance:none;width:18px;height:18px;border:2px solid var(--border-color);border-radius:50%;margin-right:12px;transition:all var(--transition-fast);position:relative;flex-shrink:0}.question-block input[type=radio]:checked{border-color:var(--accent-primary);background:var(--accent-primary)}.question-block input[type=radio]:checked:after{content:"";position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);width:6px;height:6px;background:#fff;border-radius:50%}.question-block input[type=radio]:checked+span,.question-block label:has(input:checked){color:var(--text-primary);background:#6366f11a;border-color:#6366f14d}.score-text{font-size:1.25rem;margin:20px 0;color:var(--text-secondary)}.score-text strong{color:var(--accent-secondary);font-size:1.5rem}a{color:var(--accent-primary-hover);text-decoration:none;transition:color var(--transition-fast)}a:hover{color:var(--accent-secondary)}.back-link{margin-top:28px;display:inline-block}.error-message{background:#ef44441a;border:1px solid rgba(239,68,68,.3);color:#fca5a5;padding:14px 18px;border-radius:var(--radius-md);margin-bottom:20px;font-size:14px;animation:shake .4s ease}@keyframes shake{0%,to{transform:translate(0)}20%,60%{transform:translate(-4px)}40%,80%{transform:translate(4px)}}.success-message{background:#10b9811a;border:1px solid rgba(16,185,129,.3);color:#6ee7b7;padding:14px 18px;border-radius:var(--radius-md);margin-bottom:20px;font-size:14px}.hidden{display:none}.quiz-list{list-style:none;padding:0;margin:0;text-align:left}.quiz-item{padding:16px 20px;margin-bottom:12px;background:var(--bg-secondary);border-radius:var(--radius-md);border:1px solid var(--border-color);transition:all var(--transition-fast);cursor:pointer}.quiz-item:hover{background:var(--bg-card-hover);border-color:var(--accent-primary);transform:translate(4px)}@media(max-width:600px){.container{padding:32px 24px;margin:16px}h1{font-size:1.5rem}.button-group{flex-direction:column}.btn{width:100%}}::-webkit-scrollbar{width:8px;height:8px}::-webkit-scrollbar-track{background:var(--bg-secondary)}::-webkit-scrollbar-thumb{background:var(--border-color);border-radius:4px}::-webkit-scrollbar-thumb:hover{background:#4a4a5a}