:root {
    --surface-0: #05070C;
    --surface-1: #0A0D12;
    --surface-2: #0F131C;
    --surface-3: #161D2B;
    --surface-4: #1E2636;
    --accent: #3B6DFF;
    --accent-muted: #6E9FFF;
    --text-primary: #F8F9FA;
    --text-secondary: #B8BCC4;
}

* {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'Noto Sans', sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol', 'Noto Color Emoji';
}

body {
    background: linear-gradient(135deg, var(--surface-1) 0%, var(--surface-2) 100%);
    min-height: 100vh;
}

.login-page, .register-page {
    background: linear-gradient(135deg, #1E2636 0%, #0A0D12 100%);
}

.card {
    border-radius: 16px;
    overflow: hidden;
}

.btn {
    border-radius: 999px;
    font-weight: 500;
    transition: all 0.2s ease;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

.btn-primary {
    background: linear-gradient(135deg, #3B6DFF 0%, #5B8DFF 100%);
    border: none;
}

.btn-primary:hover {
    background: linear-gradient(135deg, #2B5DEF 0%, #4B7DEF 100%);
}

.form-control:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 0.2rem rgba(59, 109, 255, 0.25);
}

.navbar-dark {
    background: linear-gradient(90deg, var(--surface-3) 0%, var(--surface-4) 100%) !important;
}

.sidebar {
    background: var(--surface-2);
    min-height: calc(100vh - 56px);
}

.sidebar .nav-link {
    color: var(--text-secondary);
    padding: 0.75rem 1rem;
    border-radius: 8px;
    margin: 0.25rem 0.5rem;
    transition: all 0.2s ease;
}

.sidebar .nav-link:hover {
    background: var(--surface-3);
    color: var(--text-primary);
}

.sidebar .nav-link.active {
    background: linear-gradient(135deg, #3B6DFF 0%, #5B8DFF 100%);
    color: white;
}

.badge {
    border-radius: 999px;
    padding: 0.35em 0.75em;
    font-weight: 500;
}

.table {
    background: white;
}

.table-hover tbody tr:hover {
    background-color: rgba(59, 109, 255, 0.05);
}

.question-card {
    background: white;
    transition: all 0.2s ease;
}

.question-card:hover {
    box-shadow: 0 4px 12px rgba(0,0,0,0.08);
    transform: translateY(-2px);
}

.alert {
    border-radius: 12px;
    border: none;
}

.pagination .page-link {
    border-radius: 8px;
    margin: 0 0.15rem;
    color: var(--accent);
}

.pagination .page-item.active .page-link {
    background: var(--accent);
    border-color: var(--accent);
}

@media (max-width: 768px) {
    .sidebar {
        position: static;
        min-height: auto;
    }
}