.subjects-header, .subject-header{text-align:center;padding:3rem 2rem;background:linear-gradient(135deg,var(--primary-color),var(--secondary-color));color:#fff;margin-bottom:2rem;width:100%;box-sizing:border-box}.subjects-header h1, .subject-header h1{font-size:2.5rem;margin-bottom:1rem;font-weight:700;line-height:1.2}.subjects-header p, .subject-header p{font-size:1.2rem;opacity:.9;max-width:800px;margin:0 auto;line-height:1.5}.subjects-grid, .topics-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(300px,1fr));gap:2rem;padding:2rem;max-width:1200px;margin:0 auto}.subject-card, .topic-card{background:#fff;border-radius:15px;padding:2rem;text-align:center;box-shadow:0 4px 20px rgba(0,0,0,.1);transition:transform 0.3s ease,box-shadow 0.3s ease;min-height:300px;display:flex;flex-direction:column;align-items:center}.subject-card:hover, .topic-card:hover{transform:translateY(-5px);box-shadow:0 6px 25px rgba(0,0,0,.15)}.subject-card i, .topic-card i{font-size:3rem;color:var(--secondary-color);margin-bottom:1.5rem}.subject-card h2, .topic-card h2{color:var(--primary-color);font-size:1.5rem;margin-bottom:1rem;font-weight:600;line-height:1.2}.subject-card p, .topic-card p{color:#666;margin-bottom:1.5rem;font-size:1rem;line-height:1.5;flex-grow:1}.close-modal:hover,.form-group label{color:var(--primary-color)}.start-quiz-btn{background-color:var(--accent-color);color:var(--primary-color);border:none;padding:1rem 2rem;border-radius:6px;cursor:pointer;font-weight:700;font-size:1.1rem;margin-top:auto;transition:background-color .3s,color .3s,box-shadow .3s;box-shadow:0 4px 16px 0 rgba(33, 113, 181, 0.22),0 1.5px 4px 0 rgba(33, 113, 181, 0.13);display:inline-block}.start-quiz-btn:hover{background-color:var(--secondary-color);color:#fff;box-shadow:0 6px 24px 0 rgba(33, 113, 181, 0.28),0 2px 8px 0 rgba(33, 113, 181, 0.16)}.modal{display:none;position:fixed;top:0;left:0;width:100%;height:100%;background-color:rgba(0,0,0,.5);z-index:1000}.modal-content{background-color:#fff;margin:15% auto;padding:2rem;border-radius:10px;width:90%;max-width:500px;position:relative}.close-modal{position:absolute;right:1rem;top:1rem;font-size:1.5rem;cursor:pointer;color:#666}.form-group{margin-bottom:1.5rem}.form-group label{display:block;margin-bottom:.5rem;font-weight:500}.form-group select{width:100%;padding:.8rem;border:1px solid #ddd;border-radius:5px;font-size:1rem;color:var(--text-color)}@media (max-width:768px){.subjects-header h1, .subject-header h1{font-size:2rem}.subjects-header p, .subject-header p{font-size:1rem}.subjects-grid, .topics-grid{grid-template-columns:1fr;padding:1rem}.modal-content{margin:20% auto;width:95%}}.keyboard-focus{outline:3px solid var(--accent-color);outline-offset:2px}@media print{.subject-card, .topic-card{break-inside:avoid;page-break-inside:avoid}.start-quiz-btn{display:none}}