body.portal-body {
    background:
        radial-gradient(circle at top left, rgba(56, 189, 248, 0.22), transparent 26%),
        radial-gradient(circle at bottom right, rgba(16, 185, 129, 0.18), transparent 26%),
        linear-gradient(135deg, #f5f9ff 0%, #eef4f7 52%, #ffffff 100%);
    color: #14213d;
}

.portal-sidebar {
    background: linear-gradient(180deg, #123b63 0%, #0f172a 100%);
    color: #fff;
}

.portal-logo {
    font-size: 2rem;
    font-weight: 800;
    letter-spacing: 0.04em;
}

.portal-logo.dark {
    color: #123b63;
}

.portal-link {
    color: rgba(255, 255, 255, 0.86);
    border-radius: 0.8rem;
    padding: 0.75rem 1rem;
    background: rgba(255, 255, 255, 0.07);
}

.portal-link:hover,
.portal-link:focus {
    color: #fff;
    background: rgba(125, 211, 252, 0.18);
}

.portal-user,
.portal-ad,
.info-card {
    background: rgba(255, 255, 255, 0.08);
    border: 1px solid rgba(255, 255, 255, 0.12);
    border-radius: 1rem;
    padding: 1rem;
}

.ad-placeholder {
    min-height: 180px;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.portal-topbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
}

.feature-card,
.content-card {
    border: 0;
    border-radius: 1.25rem;
    box-shadow: 0 20px 45px rgba(15, 23, 42, 0.08);
}

.section-title {
    color: #0f4c81;
    font-weight: 700;
}

.stat-chip {
    display: inline-flex;
    padding: 0.4rem 0.8rem;
    border-radius: 999px;
    background: #dbeafe;
    color: #0f4c81;
    font-weight: 600;
    font-size: 0.9rem;
}

.lesson-content img,
.lesson-content video {
    max-height: 320px;
    object-fit: cover;
}

.result-good {
    color: #15803d;
    font-weight: 700;
}

.result-bad {
    color: #dc2626;
    font-weight: 700;
}

@media (max-width: 991px) {
    .portal-sidebar {
        min-height: auto;
    }
}