html {
    font-size: 14px;
    position: relative;
    min-height: 100%;
}

@media (min-width: 768px) {
    html {
        font-size: 16px;
    }
}

body {
    margin: 0;
    background: #f4f7fb;
    color: #1f2937;
    font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
}

.main-wrapper {
    min-height: calc(100vh - 140px);
}

.custom-navbar {
    background: linear-gradient(90deg, #0f172a, #1e3a8a);
    box-shadow: 0 4px 14px rgba(0, 0, 0, 0.12);
    padding-top: 0.9rem;
    padding-bottom: 0.9rem;
}

.brand-text {
    color: #ffffff !important;
    font-size: 1.4rem;
    font-weight: 700;
    letter-spacing: 0.4px;
}

.custom-link {
    color: rgba(255, 255, 255, 0.9) !important;
    margin-right: 0.4rem;
    font-weight: 500;
}

    .custom-link:hover {
        color: #ffffff !important;
    }

.footer-section {
    background: #ffffff;
    border-top: 1px solid #e5e7eb;
    padding: 1rem 0;
    color: #6b7280;
}

.page-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.page-title {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 0.35rem;
    color: #111827;
}

.page-subtitle {
    margin: 0;
    color: #6b7280;
    font-size: 1rem;
}

.hero-section {
    background: linear-gradient(135deg, #1d4ed8, #0f172a);
    border-radius: 24px;
    padding: 3.2rem 2rem;
    color: white;
    box-shadow: 0 12px 30px rgba(15, 23, 42, 0.18);
    margin-bottom: 2rem;
}

.hero-title {
    font-size: 2.4rem;
    font-weight: 800;
    margin-bottom: 1rem;
}

.hero-text {
    max-width: 760px;
    font-size: 1.05rem;
    line-height: 1.7;
    color: rgba(255, 255, 255, 0.92);
    margin-bottom: 1.5rem;
}

.hero-actions {
    display: flex;
    gap: 0.85rem;
    flex-wrap: wrap;
}

.feature-card,
.filter-card,
.table-card,
.details-card,
.empty-state-card {
    background: #ffffff;
    border-radius: 20px;
    box-shadow: 0 10px 25px rgba(15, 23, 42, 0.07);
    border: 1px solid #e5e7eb;
}

.feature-card {
    padding: 1.5rem;
}

    .feature-card h3 {
        font-size: 1.2rem;
        font-weight: 700;
        margin-bottom: 0.85rem;
    }

    .feature-card p {
        color: #6b7280;
        margin-bottom: 0;
        line-height: 1.7;
    }

.filter-card {
    padding: 1.25rem;
}

.table-card {
    overflow: hidden;
}

.modern-table thead th {
    background: #f8fafc;
    color: #111827;
    border-bottom: 1px solid #e5e7eb;
    font-weight: 700;
}

.modern-table td,
.modern-table th {
    padding: 1rem;
}

.course-card {
    background: #ffffff;
    border-radius: 22px;
    overflow: hidden;
    box-shadow: 0 12px 28px rgba(15, 23, 42, 0.08);
    border: 1px solid #e5e7eb;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

    .course-card:hover {
        transform: translateY(-4px);
        box-shadow: 0 16px 34px rgba(15, 23, 42, 0.12);
    }

.course-image-wrapper {
    height: 210px;
    background: #e5e7eb;
}

.course-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.course-image-placeholder {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #6b7280;
    font-weight: 600;
    background: #e5e7eb;
}

.course-card-body {
    padding: 1.25rem;
}

.course-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin: 0;
    color: #111827;
}

.course-badge {
    background: #dbeafe;
    color: #1d4ed8;
    padding: 0.4rem 0.7rem;
    border-radius: 999px;
    font-size: 0.82rem;
    font-weight: 700;
    white-space: nowrap;
}

.course-description {
    color: #4b5563;
    line-height: 1.65;
    min-height: 72px;
}

.course-meta {
    display: grid;
    gap: 0.45rem;
    color: #374151;
    font-size: 0.95rem;
}

.course-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.summary-card {
    background: #ffffff;
    border-radius: 20px;
    border: 1px solid #e5e7eb;
    box-shadow: 0 10px 24px rgba(15, 23, 42, 0.07);
}

.summary-card-body {
    padding: 1.3rem;
}

.summary-title {
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: #111827;
}

.summary-meta {
    display: grid;
    gap: 0.45rem;
    color: #374151;
}

.empty-state-card {
    padding: 2rem;
    text-align: center;
}

.details-card {
    padding: 1.5rem;
}

.details-image {
    width: 100%;
    height: 320px;
    object-fit: cover;
    border-radius: 18px;
    box-shadow: 0 8px 18px rgba(15, 23, 42, 0.09);
}

.details-image-placeholder {
    height: 320px;
    border-radius: 18px;
    background: #e5e7eb;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #6b7280;
    font-weight: 600;
}

.details-grid {
    display: grid;
    gap: 0.9rem;
    color: #374151;
    font-size: 1rem;
}

.btn {
    border-radius: 12px;
    font-weight: 600;
}

.form-control,
.form-select {
    border-radius: 12px;
    min-height: 46px;
    box-shadow: none !important;
}

textarea.form-control {
    min-height: 120px;
}

.alert {
    border-radius: 14px;
}

.card {
    border-radius: 18px;
    border: 1px solid #e5e7eb;
}

.table {
    background: white;
}

@media (max-width: 768px) {
    .hero-title {
        font-size: 1.9rem;
    }

    .page-title {
        font-size: 1.7rem;
    }

    .course-image-wrapper {
        height: 200px;
    }

    .details-image,
    .details-image-placeholder {
        height: 240px;
    }
}