@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&display=swap');:root{--primary:#6366f1;--primary-light:#818cf8;--primary-dark:#4f46e5;--accent:#06b6d4;--accent-2:#10b981;--danger:#ef4444;--warning:#f59e0b;--success:#10b981;--bg-dark:#0b0d14;--surface:#111827;--surface-2:#1a2033;--surface-3:#1e2640;--border:rgba(255,255,255,0.08);--border-active:rgba(99,102,241,0.4);--text-primary:#f1f5f9;--text-secondary:#94a3b8;--text-muted:#475569;--radius:16px;--radius-sm:10px;--shadow:0 4px 24px rgba(0,0,0,0.3);--shadow-lg:0 20px 60px rgba(0,0,0,0.5);--transition:all 0.25s 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(max-width:768px){.portal-layout{grid-template-columns:1fr}.sidebar{display:none}.lesson-layout{grid-template-columns:1fr}.lesson-nav-panel{position:static}.portal-header{padding:16px 20px}.page-body{padding:16px}}