body {
    background: radial-gradient(circle at top, #7c3aed 0%, #2563eb 28%, #0f172a 100%);
    color: #f8fafc;
    min-height: 100vh;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

.navbar {
    background: linear-gradient(90deg, #111827 0%, #1f2937 50%, #111827 100%) !important;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.25);
    border-bottom: 2px solid #f59e0b;
}

.navbar-brand {
    font-weight: 800;
    letter-spacing: 0.6px;
    text-shadow: 0 2px 8px rgba(0, 0, 0, 0.25);
}

.nav-link {
    transition: color 0.2s ease, transform 0.2s ease;
}

.nav-link:hover {
    color: #fde68a !important;
    transform: translateY(-1px);
}

.card {
    border: none;
    border-radius: 18px;
    box-shadow: 0 14px 34px rgba(0, 0, 0, 0.22);
    overflow: hidden;
    background: rgba(255, 255, 255, 0.96);
    color: #111827;
}

.card-header {
    border-bottom: none;
    padding: 1.1rem 1.25rem;
    font-weight: 700;
}

.btn {
    border-radius: 999px;
    padding: 0.75rem 1.25rem;
    font-weight: 700;
    transition: transform 0.16s ease, box-shadow 0.16s ease, filter 0.16s ease;
}

.btn:hover {
    transform: translateY(-2px) scale(1.01);
    box-shadow: 0 10px 22px rgba(0, 0, 0, 0.18);
    filter: brightness(1.04);
}

.btn-primary {
    background: linear-gradient(135deg, #2563eb, #4f46e5);
    border: none;
}

.btn-success {
    background: linear-gradient(135deg, #10b981, #059669);
    border: none;
}

.btn-warning {
    background: linear-gradient(135deg, #f59e0b, #f97316);
    border: none;
    color: white;
}

.form-control, .form-select {
    border-radius: 12px;
    border: 1px solid #cbd5e1;
    padding: 0.75rem 0.95rem;
}

.form-control:focus, .form-select:focus {
    border-color: #f59e0b;
    box-shadow: 0 0 0 0.2rem rgba(245, 158, 11, 0.2);
}

.pregunta-bloque {
    border: 1px solid #e2e8f0;
    border-radius: 14px;
    background: linear-gradient(135deg, #ffffff, #f8fafc);
    transition: all 0.2s ease;
    animation: fadeInUp 0.35s ease both;
}

.pregunta-bloque:hover {
    background: linear-gradient(135deg, #fef3c7, #f8fafc);
    transform: translateY(-2px);
    box-shadow: 0 10px 22px rgba(15, 23, 42, 0.08);
}

.form-check-input:checked {
    background-color: #f59e0b;
    border-color: #f59e0b;
}

.table thead {
    background: linear-gradient(135deg, #7c3aed, #2563eb);
    color: white;
}

.alert {
    border: none;
    border-radius: 12px;
    box-shadow: 0 6px 14px rgba(0, 0, 0, 0.06);
}

.container {
    padding-bottom: 2rem;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(8px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.timer-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.45rem;
    padding: 0.55rem 0.85rem;
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.2);
    border: 1px solid rgba(255, 255, 255, 0.35);
    font-weight: 700;
    letter-spacing: 0.03em;
    backdrop-filter: blur(6px);
}

.quiz-timer-fixed {
    position: fixed;
    top: 1rem;
    right: 1rem;
    z-index: 1050;
    border-radius: 999px;
    padding: 0.6rem 1rem;
    box-shadow: 0 10px 24px rgba(0, 0, 0, 0.2);
}

.quiz-page .card {
    margin-top: 4rem;
}