:root{font-family:Inter,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,Cantarell,sans-serif;line-height:1.6;font-weight:400;--primary: #6366f1;--primary-hover: #4f46e5;--primary-light: #eef2ff;--secondary: #8b5cf6;--accent: #06b6d4;--success: #10b981;--warning: #f59e0b;--danger: #ef4444;--text-dark: #1e293b;--text-medium: #475569;--text-light: #64748b;--bg-primary: #ffffff;--bg-secondary: #f8fafc;--bg-tertiary: #f1f5f9;--border: #e2e8f0;--shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, .05);--shadow: 0 4px 6px -1px rgba(0, 0, 0, .1), 0 2px 4px -1px rgba(0, 0, 0, .06);--shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, .1), 0 4px 6px -2px rgba(0, 0, 0, .05);--shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, .1), 0 10px 10px -5px rgba(0, 0, 0, .04);font-synthesis:none;text-rendering:optimizeLegibility;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}*{box-sizing:border-box;margin:0;padding:0}body{margin:0;min-width:320px;min-height:100vh;background:linear-gradient(135deg,#667eea,#764ba2);background-attachment:fixed;color:var(--text-dark)}#root{width:100%;min-height:100vh}h1,h2,h3,h4,h5,h6{line-height:1.2;font-weight:700;color:var(--text-dark)}button{font-family:inherit;cursor:pointer}.home-container{text-align:center;padding:6rem 2rem;max-width:900px;margin:0 auto;animation:fadeIn .6s ease-out}@keyframes fadeIn{0%{opacity:0;transform:translateY(20px)}to{opacity:1;transform:translateY(0)}}.home-container h1{font-size:4rem;margin-bottom:1.5rem;color:#fff;text-shadow:0 4px 20px rgba(0,0,0,.2);font-weight:900;letter-spacing:-2px;line-height:1.1}.home-container p{font-size:1.5rem;color:#fffffff2;margin-bottom:3rem;font-weight:400;text-shadow:0 2px 10px 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h1{font-size:2.5rem}.home-container p{font-size:1.2rem}}.login-container{display:flex;justify-content:center;align-items:center;min-height:calc(100vh - 200px);padding:2rem;animation:fadeIn .5s ease-out}@keyframes fadeIn{0%{opacity:0;transform:translateY(10px)}to{opacity:1;transform:translateY(0)}}.login-card{background:#fff;padding:3rem;border-radius:24px;box-shadow:var(--shadow-xl);width:100%;max-width:440px;border:1px solid rgba(226,232,240,.8)}.login-card h2{margin-top:0;margin-bottom:.5rem;text-align:center;color:var(--text-dark);font-size:2rem;font-weight:800}.login-card h2+p{text-align:center;color:var(--text-light);margin-bottom:2rem;font-size:.95rem}.form-group{margin-bottom:1.5rem}.form-group label{display:block;margin-bottom:.6rem;font-weight:600;color:var(--text-dark);font-size:.95rem}.form-group input{width:100%;padding:.9rem 1rem;border:2px solid var(--border);border-radius:10px;font-size:1rem;box-sizing:border-box;transition:all .2s 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h1{font-size:3rem;margin-bottom:.75rem;color:#fff;text-shadow:0 4px 20px rgba(0,0,0,.2);font-weight:900;letter-spacing:-1px}.questions-header p{color:#fffffff2;font-size:1.25rem;text-shadow:0 2px 10px rgba(0,0,0,.15)}.auth-badge{display:inline-block;margin-top:.5rem;padding:.4rem 1rem;background:linear-gradient(135deg,#d4f8e8,#abefc6);color:#065f46;border-radius:20px;font-size:.875rem;font-weight:700}.filters{display:flex;gap:1rem;margin-bottom:2rem;flex-wrap:wrap;align-items:flex-end;background:#fff;padding:1.5rem;border-radius:16px;box-shadow:var(--shadow-lg);border:1px solid rgba(226,232,240,.8)}.search-box{flex:1;min-width:280px}.search-box input{width:100%;padding:.9rem 1.2rem;border:2px solid var(--border);border-radius:10px;font-size:1rem;box-sizing:border-box;transition:all .2s ease;background:var(--bg-secondary)}.search-box input:focus{outline:none;border-color:var(--primary);background:#fff;box-shadow:0 0 0 4px #6366f11a}.search-box 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h3{margin:0;color:var(--text-dark);font-size:1.4rem;flex:1;font-weight:700;line-height:1.3}.difficulty{padding:.4rem 1rem;border-radius:20px;font-size:.85rem;font-weight:700;white-space:nowrap;text-transform:uppercase;letter-spacing:.5px;box-shadow:var(--shadow-sm)}.difficulty-easy{background:linear-gradient(135deg,#d4f8e8,#abefc6);color:#065f46}.difficulty-medium{background:linear-gradient(135deg,#fef3c7,#fcd34d);color:#78350f}.difficulty-hard{background:linear-gradient(135deg,#fecaca,#fca5a5);color:#991b1b}.question-description{color:var(--text-medium);line-height:1.7;margin-bottom:1.5rem;font-size:1.05rem}.question-footer{display:flex;justify-content:space-between;align-items:center;gap:1rem;flex-wrap:wrap}.question-tags{display:flex;gap:.6rem;flex-wrap:wrap;flex:1}.tag{background:linear-gradient(135deg,var(--primary-light) 0%,#ddd6fe 100%);color:var(--primary);padding:.4rem 1rem;border-radius:20px;font-size:.875rem;font-weight:600;transition:all .2s ease;border:1px solid transparent}.tag:hover{background:var(--primary);color:#fff;transform:translateY(-1px)}.btn-small{padding:.65rem 1.5rem;font-size:.9rem;background:linear-gradient(135deg,var(--primary) 0%,var(--secondary) 100%);color:#fff;border:none;border-radius:10px;font-weight:700;cursor:pointer;transition:all .3s ease;box-shadow:var(--shadow);white-space:nowrap}.btn-small:hover{transform:translateY(-2px);box-shadow:var(--shadow-lg)}.no-results{text-align:center;color:var(--text-light);padding:4rem 2rem;font-size:1.25rem;background:#fff;border-radius:16px;box-shadow:var(--shadow-lg)}.results-count{text-align:center;margin-top:2.5rem;color:#fff;font-size:1rem;font-weight:600;text-shadow:0 2px 10px rgba(0,0,0,.15)}.loading-container{display:flex;flex-direction:column;align-items:center;justify-content:center;padding:4rem 2rem;background:#fff;border-radius:16px;box-shadow:var(--shadow-lg)}.loading-spinner{width:50px;height:50px;border:4px solid 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h1{font-size:2rem}.filters{flex-direction:column;align-items:stretch}.search-box,.filter-group{min-width:100%}.question-header{flex-direction:column;gap:1rem}.question-footer{flex-direction:column;align-items:flex-start}.btn-small{width:100%}}.modal-overlay{position:fixed;inset:0;background:#000000b3;-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px);display:flex;align-items:center;justify-content:center;z-index:1000;padding:1rem;animation:fadeIn .2s ease-out}.modal-content{background:#fff;border-radius:20px;max-width:800px;width:100%;max-height:90vh;overflow-y:auto;box-shadow:0 20px 50px #0000004d;animation:slideUp .3s ease-out}@keyframes slideUp{0%{opacity:0;transform:translateY(20px)}to{opacity:1;transform:translateY(0)}}.modal-header{display:flex;justify-content:space-between;align-items:center;padding:2rem;border-bottom:2px solid var(--border);background:linear-gradient(135deg,var(--primary-light) 0%,#ddd6fe 100%)}.modal-header h2{margin:0;color:var(--primary);font-size:1.75rem;font-weight:800}.modal-close{background:transparent;border:none;font-size:2rem;cursor:pointer;color:var(--text-medium);transition:all .2s ease;width:40px;height:40px;display:flex;align-items:center;justify-content:center;border-radius:10px}.modal-close:hover{background:#0000001a;color:var(--text-dark);transform:rotate(90deg)}.modal-body{padding:2rem}.question-display{background:var(--bg-secondary);padding:1.5rem;border-radius:12px;margin-bottom:2rem;border:2px solid var(--border)}.question-display h3{margin:0 0 1rem;color:var(--text-dark);font-size:1.4rem;font-weight:700}.question-display p{margin:0 0 1rem;color:var(--text-medium);line-height:1.6;font-size:1.05rem}.question-meta{display:flex;gap:1rem;flex-wrap:wrap}.category-badge{padding:.4rem 1rem;border-radius:20px;font-size:.85rem;font-weight:700;background:linear-gradient(135deg,#e0e7ff,#c7d2fe);color:var(--primary)}.reference-answer{margin-top:1.5rem;padding:1rem;background:linear-gradient(135deg,#fef3c7,#fde68a);border:2px solid #fbbf24;border-radius:12px;cursor:pointer}.reference-answer summary{font-weight:700;color:#78350f;cursor:pointer;padding:.5rem;border-radius:8px;transition:all .2s ease;-webkit-user-select:none;user-select:none}.reference-answer summary:hover{background:#ffffff4d}.reference-answer p{margin:1rem 0 0;padding:1rem;background:#fff;border-radius:8px;line-height:1.7}.answer-section{margin-bottom:1.5rem}.answer-section label{display:block;margin-bottom:.75rem;font-weight:700;color:var(--text-dark);font-size:1.1rem}.answer-section textarea{width:100%;padding:1rem;border:2px solid var(--border);border-radius:12px;font-size:1rem;font-family:inherit;line-height:1.6;resize:vertical;transition:all .2s ease;box-sizing:border-box}.answer-section textarea:focus{outline:none;border-color:var(--primary);box-shadow:0 0 0 4px #6366f11a}.btn-primary{width:100%;padding:1rem 2rem;background:linear-gradient(135deg,var(--primary) 0%,var(--secondary) 100%);color:#fff;border:none;border-radius:12px;font-size:1.1rem;font-weight:700;cursor:pointer;transition:all .3s ease;box-shadow:var(--shadow-lg)}.btn-primary:hover:not(:disabled){transform:translateY(-2px);box-shadow:var(--shadow-xl)}.btn-primary:disabled{opacity:.6;cursor:not-allowed}.evaluation-results{animation:slideUp .4s ease-out}.evaluation-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:1.5rem;padding-bottom:1rem;border-bottom:2px solid var(--border)}.evaluation-header h3{margin:0;color:var(--text-dark);font-size:1.5rem;font-weight:800}.score-badge{padding:.75rem 1.5rem;border-radius:30px;font-size:1.1rem;font-weight:800;background:linear-gradient(135deg,var(--primary) 0%,var(--secondary) 100%);color:#fff;box-shadow:var(--shadow-lg)}.correctness{padding:1rem 1.5rem;border-radius:12px;font-size:1.1rem;font-weight:700;margin-bottom:1.5rem;text-align:center}.correctness.correct{background:linear-gradient(135deg,#d4f8e8,#abefc6);color:#065f46}.correctness.incorrect{background:linear-gradient(135deg,#fef3c7,#fcd34d);color:#78350f}.feedback-section{margin-bottom:1.5rem;padding:1.25rem;background:var(--bg-secondary);border-radius:12px;border-left:4px solid var(--primary)}.feedback-section h4{margin:0 0 .75rem;color:var(--text-dark);font-size:1.1rem;font-weight:700}.feedback-section ul{margin:0;padding-left:1.5rem}.feedback-section li{color:var(--text-medium);line-height:1.7;margin-bottom:.5rem}.marcus-comment{background:linear-gradient(135deg,#e0e7ff,#ddd6fe);padding:1.5rem;border-radius:12px;margin-bottom:1.5rem}.marcus-comment h4{margin:0 0 .75rem;color:var(--primary);font-size:1.1rem;font-weight:700}.marcus-comment p{margin:0;color:var(--text-dark);line-height:1.7;font-size:1.05rem}.btn-secondary{width:100%;padding:1rem 2rem;background:linear-gradient(135deg,#6b7280,#4b5563);color:#fff;border:none;border-radius:12px;font-size:1rem;font-weight:700;cursor:pointer;transition:all .3s ease;box-shadow:var(--shadow)}.btn-secondary:hover{transform:translateY(-2px);box-shadow:var(--shadow-lg);background:linear-gradient(135deg,#4b5563,#374151)}@media(max-width:768px){.modal-content{max-height:95vh;margin:.5rem}.modal-header,.modal-body{padding:1.5rem}.evaluation-header{flex-direction:column;gap:1rem;align-items:flex-start}}.app{min-height:100vh;display:flex;flex-direction:column;background:linear-gradient(135deg,#667eea,#764ba2)}.navbar{background:#fffffffa;-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);border-bottom:1px solid rgba(226,232,240,.8);padding:1rem 0;position:sticky;top:0;z-index:100;box-shadow:var(--shadow-sm)}.navbar-container{max-width:1200px;margin:0 auto;padding:0 2rem;display:flex;justify-content:space-between;align-items:center}.navbar-brand{font-size:1.5rem;font-weight:800;background:linear-gradient(135deg,var(--primary) 0%,var(--secondary) 100%);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text;text-decoration:none;transition:all .3s ease;letter-spacing:-.5px}.navbar-brand:hover{transform:scale(1.02)}.navbar-links{display:flex;gap:2rem;align-items:center}.nav-link{color:var(--text-medium);text-decoration:none;font-weight:600;font-size:.95rem;transition:all .2s ease;position:relative;padding:.5rem 0}.nav-link:after{content:"";position:absolute;bottom:0;left:0;width:0;height:2px;background:linear-gradient(90deg,var(--primary),var(--secondary));transition:width .3s ease}.nav-link:hover{color:var(--primary)}.nav-link:hover:after{width:100%}.nav-button{background:none;border:none;padding:.5rem 0;margin:0;font-family:inherit;font-size:inherit}.nav-button:hover{background:none}.user-email{color:var(--text-dark);font-weight:600;font-size:.9rem;background:var(--bg-secondary);padding:.5rem 1rem;border-radius:8px;border:1px solid var(--border)}.logout-btn{background:linear-gradient(135deg,var(--primary) 0%,var(--secondary) 100%);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text;font-weight:700}.logout-btn:hover{opacity:.8}.main-content{flex:1;width:100%}.footer{background:#fffffff2;-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);border-top:1px solid rgba(226,232,240,.8);padding:2rem;text-align:center;color:var(--text-light);font-size:.875rem;margin-top:4rem}.footer p{margin:0}