:root{--font-sans: "Inter", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;--bg-gradient: linear-gradient(135deg, #f6f9fc 0%, #eef2f7 100%);--stripe-blue: #635bff;--stripe-blue-hover: #534bc6;--stripe-light-blue: #00d4ff;--stripe-dark: #0a2540;--text-main: #333d47;--text-muted: #697386;--card-bg: rgba(255, 255, 255, .9);--card-border: rgba(227, 233, 243, .85);--success-color: #00d4b2;--error-color: #ff5f5f;--accent-blue-soft: rgba(99, 91, 255, .05);--success-soft: rgba(0, 212, 178, .08);--error-soft: rgba(255, 95, 95, .08);--shadow-sm: 0 2px 4px rgba(0,0,0,.02);--shadow-md: 0 10px 30px -10px rgba(0, 0, 0, .05);--shadow-lg: 0 15px 35px -10px rgba(0, 0, 0, .08)}*{box-sizing:border-box}body{margin:0;padding:0;font-family:var(--font-sans);background:var(--bg-gradient);color:var(--text-main);min-height:100vh;display:flex;flex-direction:column;-webkit-font-smoothing:antialiased}::-webkit-scrollbar{width:6px;height:6px}::-webkit-scrollbar-track{background:transparent}::-webkit-scrollbar-thumb{background:#69738633;border-radius:4px}::-webkit-scrollbar-thumb:hover{background:#69738666}.card{background:var(--card-bg);border:1px solid var(--card-border);backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);border-radius:12px;padding:24px;box-shadow:var(--shadow-md);transition:transform .2s cubic-bezier(.16,1,.3,1),box-shadow .2s ease}.card:hover{transform:translateY(-2px);box-shadow:var(--shadow-lg)}.btn-primary{background-color:var(--stripe-blue);color:#fff;border:none;padding:10px 20px;border-radius:6px;font-weight:600;font-size:14px;cursor:pointer;box-shadow:0 4px 6px -1px #00000014,0 2px 4px -1px #0000000a;transition:background-color .15s ease,transform .15s ease,box-shadow .15s ease;display:inline-flex;align-items:center;justify-content:center;gap:8px}.btn-primary:hover{background-color:var(--stripe-blue-hover);transform:translateY(-1px);box-shadow:0 6px 12px -2px #635bff33}.btn-primary:active{transform:translateY(0)}.btn-primary:disabled{background-color:var(--text-muted);opacity:.6;cursor:not-allowed;transform:none;box-shadow:none}.navbar{background:#ffffffbf;backdrop-filter:blur(10px);-webkit-backdrop-filter:blur(10px);border-bottom:1px solid var(--card-border);padding:16px 32px;display:flex;justify-content:space-between;align-items:center;position:sticky;top:0;z-index:100;box-shadow:0 1px 2px #00000003}.navbar-brand{font-weight:800;font-size:18px;color:var(--stripe-dark)}.navbar-menu{display:flex;gap:16px;align-items:center}.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(300px,1fr));gap:24px}input[type=text],input[type=email],input[type=password],input[type=date],select{font-family:var(--font-sans);border:1px solid var(--card-border);border-radius:6px;padding:10px 12px;font-size:14px;color:var(--text-main);background:#fff;transition:border-color .15s ease,box-shadow .15s ease;width:100%}input:focus,select:focus{outline:none;border-color:var(--stripe-blue);box-shadow:0 0 0 3px #635bff26}.fade-in{animation:fadeIn .3s ease-out}@keyframes fadeIn{0%{opacity:0;transform:translateY(4px)}to{opacity:1;transform:translateY(0)}}.two-col-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px}@media (max-width: 768px){body{background:#f6f9fc}.navbar{padding:12px 16px;flex-direction:column;gap:12px;align-items:center;position:static}.navbar-brand{margin-bottom:4px}.navbar-menu{display:flex;flex-wrap:wrap;gap:8px;width:100%;justify-content:center}.navbar-menu button{font-size:12px;padding:8px 10px;flex:1 1 calc(33.33% - 8px);min-width:80px}.grid{grid-template-columns:1fr;gap:16px}.card{padding:16px}.two-col-grid{grid-template-columns:1fr;gap:12px}.news-layout-grid{grid-template-columns:1fr!important}}@media print{body{background:#fff!important;color:#000!important;font-size:12pt}.navbar,.btn-primary,.noprint,button{display:none!important}.card{border:none!important;box-shadow:none!important;background:none!important;-webkit-backdrop-filter:none!important;backdrop-filter:none!important;padding:0!important;margin-bottom:20pt!important;page-break-inside:avoid}h1,h2,h3{page-break-after:avoid}.page-break{page-break-before:always}}.animate-spin{animation:spin 1s linear infinite}@keyframes spin{0%{transform:rotate(0)}to{transform:rotate(360deg)}}.stats-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:20px;margin-bottom:32px}.stat-card{background:var(--card-bg);border:1px solid var(--card-border);border-radius:12px;padding:20px;box-shadow:var(--shadow-sm);transition:all .2s ease}.stat-card:hover{transform:translateY(-2px);box-shadow:var(--shadow-lg)}.stat-title{font-size:13px;color:var(--text-muted);margin:0 0 8px;font-weight:600}.stat-value{font-size:32px;font-weight:800;margin:0;color:var(--stripe-dark)}.stat-trend{font-size:11px;margin-top:6px;color:var(--text-muted);display:flex;align-items:center;gap:4px}.text-success{color:var(--success-color)!important}.text-error{color:var(--error-color)!important}.dashboard-layout{display:grid;grid-template-columns:1fr 450px;gap:24px}@media (max-width: 1024px){.dashboard-layout{grid-template-columns:1fr}}.table-container{overflow-x:auto}table{width:100%;border-collapse:collapse;text-align:left}th{color:var(--text-muted);font-weight:600;font-size:12px;text-transform:uppercase;padding:12px 16px;border-bottom:1px solid var(--card-border)}td{padding:14px 16px;font-size:14px;border-bottom:1px solid var(--card-border);color:var(--text-main)}tr.student-row{cursor:pointer;transition:background-color .15s ease}tr.student-row:hover{background-color:var(--accent-blue-soft)}tr.student-row.selected{background-color:#635bff14;border-left:3px solid var(--stripe-blue)}.student-badge{display:inline-flex;align-items:center;gap:10px}.student-avatar{width:28px;height:28px;border-radius:50%;background:var(--stripe-blue);color:#fff;font-size:12px;font-weight:700;display:flex;align-items:center;justify-content:center}.student-info{display:flex;flex-direction:column}.student-email{font-weight:600;color:var(--stripe-dark)}.student-date{font-size:11px;color:var(--text-muted)}.filter-bar{display:flex;gap:12px;margin-bottom:20px}.search-input{padding:8px 12px;border:1px solid var(--card-border);border-radius:6px;font-size:13px;width:100%;max-width:300px;background:#fff}.search-input:focus{outline:none;border-color:var(--stripe-blue);box-shadow:0 0 0 3px #635bff26}.detail-panel{display:flex;flex-direction:column;gap:20px}.panel-header{border-bottom:1px solid var(--card-border);padding-bottom:16px}.panel-section-title{font-size:12px;color:var(--text-muted);font-weight:700;text-transform:uppercase;margin:16px 0 8px}.history-item{display:flex;justify-content:space-between;align-items:center;padding:10px 12px;border-radius:6px;background:#f8fafc;border:1px solid var(--card-border);margin-bottom:8px;font-size:13px}.history-meta{display:flex;flex-direction:column}.history-date{color:var(--text-muted);font-size:11px}.history-score{font-weight:700}.wrong-question-card{border:1px solid var(--card-border);border-radius:8px;padding:12px;background:#fff;margin-bottom:10px;font-size:13px}.wrong-question-title{font-weight:600;color:var(--stripe-dark);margin:0 0 8px;line-height:1.4}.wrong-option{padding:6px 10px;border-radius:4px;margin-bottom:4px;font-size:12px;border:1px solid var(--card-border)}.wrong-option.correct{background:var(--success-soft);color:var(--success-color);border:1px solid rgba(0,212,178,.2);font-weight:700}.wrong-option.user-wrong{background:var(--error-soft);color:var(--error-color);border:1px solid rgba(255,95,95,.2);font-weight:700}.mistake-rank-item{border:1px solid var(--card-border);border-radius:10px;padding:16px;margin-bottom:16px;background:#fff}.mistake-badge{background:var(--error-color);color:#fff;font-size:11px;font-weight:700;padding:2px 6px;border-radius:4px;margin-right:8px}.mistake-stats{display:flex;gap:16px;font-size:12px;color:var(--text-muted);margin-top:8px;padding-top:8px;border-top:1px dashed var(--card-border)}.btn-tab{background:none;border:none;padding:8px 16px;font-size:14px;font-weight:600;color:var(--text-muted);cursor:pointer;border-radius:6px;transition:all .2s ease}.btn-tab.active{color:var(--stripe-blue);background:var(--accent-blue-soft)}