:root {
    --primary: #0F172A;
    --primary-accent: #2563EB;
    --accent-hover: #1D4ED8;
    --bg-page: #F8FAFC;
    --bg-surface: #FFFFFF;
    --border-color: #E2E8F0;
    --text-main: #0F172A;
    --text-muted: #64748B;
    --success: #10B981;
    --danger: #EF4444;
    --warning: #F59E0B;
    --radius: 12px;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
body { background: var(--bg-page); color: var(--text-main); font-family: 'Plus Jakarta Sans', system-ui, sans-serif; line-height: 1.5; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 1.5rem; }
.navbar { background: var(--bg-surface); border-bottom: 1px solid var(--border-color); padding: 1rem 0; }
.nav-container { display: flex; justify-content: space-between; align-items: center; }
.brand { font-size: 1.25rem; font-weight: 800; display: flex; align-items: center; gap: 0.5rem; }
.brand-badge { background: #EFF6FF; color: var(--primary-accent); padding: 4px 8px; border-radius: 6px; }
.hero { padding: 4rem 0 3rem; text-align: center; }
.badge-pill { display: inline-block; background: #EFF6FF; color: var(--primary-accent); font-size: 0.85rem; font-weight: 600; padding: 0.35rem 1rem; border-radius: 9999px; margin-bottom: 1.5rem; }
.hero h1 { font-size: 3rem; font-weight: 800; margin-bottom: 1rem; }
.hero-subtext { font-size: 1.15rem; color: var(--text-muted); max-width: 650px; margin: 0 auto 2rem; }
.hero-actions { display: flex; justify-content: center; gap: 1rem; }
.features { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 2rem; margin-bottom: 4rem; }
.feature-card { background: var(--bg-surface); padding: 2rem; border-radius: var(--radius); border: 1px solid var(--border-color); }
.f-icon { font-size: 2rem; margin-bottom: 1rem; }
.auth-wrap { min-height: 80vh; display: flex; align-items: center; justify-content: center; padding: 2rem; }
.auth-card { background: var(--bg-surface); border: 1px solid var(--border-color); border-radius: var(--radius); padding: 2.5rem; width: 100%; max-width: 440px; }
.auth-header { text-align: center; margin-bottom: 2rem; }
.auth-footer { text-align: center; margin-top: 1.5rem; font-size: 0.9rem; }
.layout-wrapper { display: flex; min-height: 100vh; }
.sidebar { width: 250px; background: var(--primary); color: #fff; padding: 2rem 1.25rem; flex-shrink: 0; }
.sidebar-brand { font-size: 1.25rem; font-weight: 800; margin-bottom: 2rem; display: flex; align-items: center; gap: 0.5rem; }
.badge-tag { background: rgba(255,255,255,0.15); font-size: 0.75rem; padding: 2px 6px; border-radius: 4px; }
.sidebar-nav a { display: block; color: #94A3B8; text-decoration: none; padding: 0.75rem 1rem; border-radius: 8px; margin-bottom: 0.5rem; font-weight: 500; }
.sidebar-nav a.active, .sidebar-nav a:hover { background: rgba(255,255,255,0.1); color: #fff; }
.nav-logout { margin-top: 3rem; color: #F87171 !important; }
.main-content { flex-grow: 1; padding: 2.5rem; background: var(--bg-page); overflow-x: auto; }
.topbar { display: flex; justify-content: space-between; align-items: center; margin-bottom: 2rem; }
.stats-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 1.5rem; margin-bottom: 2rem; }
.stat-card { background: var(--bg-surface); padding: 1.5rem; border-radius: var(--radius); border: 1px solid var(--border-color); }
.stat-label { display: block; font-size: 0.85rem; color: var(--text-muted); margin-bottom: 0.5rem; }
.stat-value { font-size: 2rem; font-weight: 800; }
.stat-success .stat-value { color: var(--success); }
.stat-danger .stat-value { color: var(--danger); }
.stat-accent .stat-value { color: var(--primary-accent); }
.panel-card { background: var(--bg-surface); border: 1px solid var(--border-color); border-radius: var(--radius); padding: 1.75rem; margin-bottom: 2rem; }
.panel-card h3 { margin-bottom: 1.25rem; }
.dashboard-columns { display: grid; grid-template-columns: 2fr 1fr; gap: 2rem; }
.table-responsive { overflow-x: auto; }
.data-table { width: 100%; border-collapse: collapse; }
.data-table th, .data-table td { padding: 0.75rem 1rem; text-align: left; border-bottom: 1px solid var(--border-color); }
.data-table th { background: #F1F5F9; color: var(--text-muted); }
.btn { display: inline-flex; align-items: center; justify-content: center; padding: 0.6rem 1.2rem; border-radius: 8px; font-weight: 600; text-decoration: none; border: 1px solid transparent; cursor: pointer; }
.btn-primary { background: var(--primary-accent); color: #fff; }
.btn-secondary { background: #E2E8F0; color: var(--text-main); }
.btn-outline { border-color: var(--border-color); color: var(--text-main); }
.btn-block { width: 100%; }
.form-group { margin-bottom: 1.25rem; }
.form-group label { display: block; margin-bottom: 0.5rem; font-weight: 600; font-size: 0.875rem; }
.form-group input, .form-group select { width: 100%; padding: 0.65rem 0.85rem; border: 1px solid var(--border-color); border-radius: 6px; }
.inline-form { display: flex; gap: 1rem; align-items: center; }
.filter-bar { margin-bottom: 1.5rem; }
.student-shell { min-height: 100vh; background: #F8FAFC; }
.student-topbar { background: var(--bg-surface); padding: 1rem 1.5rem; display: flex; justify-content: space-between; border-bottom: 1px solid var(--border-color); }
.student-profile-card { background: var(--bg-surface); padding: 1.5rem; border-radius: var(--radius); border: 1px solid var(--border-color); display: flex; align-items: center; gap: 1.5rem; margin: 1.5rem 0; }
.sp-avatar { width: 56px; height: 56px; border-radius: 50%; background: var(--primary-accent); color: #fff; display: flex; align-items: center; justify-content: center; font-size: 1.5rem; font-weight: 700; }
.status-banner { padding: 1rem; border-radius: var(--radius); margin-bottom: 1.5rem; text-align: center; }
.sb-present { background: #DCFCE7; color: #166534; }
.sb-absent { background: #FEE2E2; color: #991B1B; }
.student-stats-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1rem; margin-bottom: 1.5rem; }
.s-card { background: var(--bg-surface); padding: 1rem; border-radius: var(--radius); border: 1px solid var(--border-color); text-align: center; }
.s-card-metric { font-size: 1.5rem; font-weight: 800; }
.badge { display: inline-block; padding: 3px 8px; border-radius: 4px; font-size: 0.75rem; font-weight: 700; }
.badge-success { background: #DCFCE7; color: #15803D; }
.badge-danger { background: #FEE2E2; color: #B91C1C; }
.badge-warning { background: #FEF3C7; color: #B45309; }
.badge-light { background: #F1F5F9; }
.key-box { display: block; padding: 0.5rem; background: #000; color: #00FF66; font-family: monospace; border-radius: 4px; }
.modal { display: none; position: fixed; inset: 0; background: rgba(0,0,0,0.5); z-index: 1000; }
.modal-content { background: #fff; max-width: 500px; margin: 10vh auto; padding: 2rem; border-radius: var(--radius); }
.modal-actions { display: flex; justify-content: flex-end; gap: 1rem; margin-top: 1.5rem; }
.alert { padding: 1rem; border-radius: 8px; margin-bottom: 1.5rem; }
.alert-info { background: #EFF6FF; color: #1E40AF; }
.alert-warning { background: #FEF3C7; color: #92400E; }
.alert-danger { background: #FEE2E2; color: #991B1B; }
.main-footer { border-top: 1px solid var(--border-color); background: #fff; padding: 1.5rem 0; margin-top: 4rem; }
.footer-content { display: flex; justify-content: space-between; font-size: 0.85rem; color: var(--text-muted); }
.dot { height: 8px; width: 8px; background: var(--success); border-radius: 50%; display: inline-block; }
@media (max-width: 768px) {
    .layout-wrapper { flex-direction: column; }
    .sidebar { width: 100%; }
    .dashboard-columns { grid-template-columns: 1fr; }
    .hero h1 { font-size: 2.2rem; }
}