:root{--primary: #2563eb;--primary-dark: #1d4ed8;--secondary: #64748b;--success: #10b981;--danger: #ef4444;--warning: #f59e0b;--background: #f8fafc;--surface: #ffffff;--border: #e2e8f0;--text: #1e293b;--text-light: #64748b}*{margin:0;padding:0;box-sizing:border-box}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,sans-serif;background:var(--background);color:var(--text);line-height:1.6}.container{max-width:1200px;margin:0 auto;padding:20px}.card{background:var(--surface);border-radius:8px;box-shadow:0 1px 3px #0000001a;padding:20px;margin-bottom:20px}.btn{display:inline-flex;align-items:center;justify-content:center;padding:10px 20px;border:none;border-radius:6px;font-size:14px;font-weight:500;cursor:pointer;transition:all .2s}.btn-primary{background:var(--primary);color:#fff}.btn-primary:hover{background:var(--primary-dark)}.btn-secondary{background:var(--secondary);color:#fff}.btn-danger{background:var(--danger);color:#fff}.btn:disabled{opacity:.5;cursor:not-allowed}input,select,textarea{width:100%;padding:10px;border:1px solid var(--border);border-radius:6px;font-size:14px}input:focus,select:focus,textarea:focus{outline:none;border-color:var(--primary)}table{width:100%;border-collapse:collapse}th,td{padding:12px;text-align:left;border-bottom:1px solid var(--border)}th{background:var(--background);font-weight:600}.header{display:flex;justify-content:space-between;align-items:center;margin-bottom:20px;padding-bottom:20px;border-bottom:1px solid var(--border)}.header h1{font-size:24px}.nav{display:flex;gap:10px;margin-bottom:20px}.nav a{padding:10px 20px;text-decoration:none;color:var(--text);border-radius:6px;background:var(--surface)}.nav a.active{background:var(--primary);color:#fff}.form-group{margin-bottom:15px}.form-group label{display:block;margin-bottom:5px;font-weight:500}.error{color:var(--danger);font-size:14px;margin-top:5px}.success{color:var(--success);font-size:14px;margin-top:5px}.loading{text-align:center;padding:40px;color:var(--text-light)}.matrix-table input{width:60px;text-align:center}.violation-warning{background:#fef2f2;border:1px solid #fecaca;color:#dc2626;padding:10px;border-radius:6px;margin-bottom:10px}.exam-timer{position:fixed;top:20px;right:20px;background:var(--primary);color:#fff;padding:10px 20px;border-radius:8px;font-size:20px;font-weight:600;z-index:1000}.exam-timer.warning{background:var(--danger)}