*{box-sizing:border-box;margin:0;padding:0}:root{--primary:#1a2744;--primary-dark:#253558;--secondary:#f5a623;--success:#10b981;--danger:#ef4444;--bg:#f8fafc;--surface:#fff;--border:#e2e8f0;--text:#1e293b;--text-muted:#64748b}body{font-family:system-ui,-apple-system,sans-serif;background:var(--bg);color:var(--text);line-height:1.6}.btn{display:inline-flex;align-items:center;gap:.5rem;padding:.625rem 1.25rem;border-radius:.75rem;font-size:.9375rem;font-weight:600;cursor:pointer;border:none;transition:all .2s}.btn:hover{transform:translateY(-1px);box-shadow:0 4px 12px rgba(0,0,0,.1)}.btn-primary{background:var(--secondary);color:var(--primary);box-shadow:0 4px 14px rgba(245,166,35,.25)}.btn-primary:hover{background:#e09510}.btn-secondary{background:var(--primary);color:#fff}.btn-outline{background:transparent;border:1.5px solid var(--border);color:var(--text)}.btn-outline:hover{border-color:var(--primary);color:var(--primary)}.card{background:var(--surface);border:1px solid var(--border);border-radius:1rem;padding:1.5rem;transition:box-shadow .2s,transform .2s}.card:hover{box-shadow:0 8px 24px rgba(0,0,0,.06)}.nav{display:flex;align-items:center;gap:1.5rem;padding:0 1.5rem;height:56px;background:var(--surface);border-bottom:1px solid var(--border);position:-webkit-sticky;position:sticky;top:0;z-index:100}.nav-brand{font-size:1rem;font-weight:700;color:var(--primary);text-decoration:none;margin-right:auto}.nav-link{color:var(--text-muted);text-decoration:none;font-size:.9rem;font-weight:500;transition:color .15s}.nav-link:hover{color:var(--primary)}.page{max-width:960px;margin:0 auto;padding:2rem}.section-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));grid-gap:1rem;gap:1rem;margin-top:1.5rem}.section-card{display:flex;flex-direction:column;align-items:center;gap:.5rem;padding:1.5rem;background:var(--surface);border:2px solid var(--border);border-radius:1rem;cursor:pointer;text-decoration:none;color:var(--text);transition:all .2s}.section-card:hover{border-color:var(--secondary);box-shadow:0 8px 24px rgba(0,0,0,.06);transform:translateY(-2px)}.section-card h3{font-size:1rem;font-weight:700}.section-card span{font-size:.875rem;color:var(--text-muted)}.badge{display:inline-block;padding:.25rem .625rem;border-radius:9999px;font-size:.75rem;font-weight:500}.badge-easy{background:#d1fae5;color:#065f46}.badge-medium{background:#fef3c7;color:#92400e}.badge-hard{background:#fee2e2;color:#991b1b}.timer{font-size:1.5rem;font-weight:700;font-feature-settings:"tnum";font-variant-numeric:tabular-nums;color:var(--danger)}@media (max-width:640px){.nav-desktop-links{display:none!important}.nav-hamburger,.nav-mobile-menu{display:flex!important}.page{padding:1rem}.section-grid{grid-template-columns:repeat(auto-fit,minmax(160px,1fr));gap:.75rem;margin-top:1rem}.card,.section-card{padding:1rem}.mock-test-grid{grid-template-columns:1fr}}