.navbar-modern {
    background: rgba(255, 255, 255, 0.96);
    border-bottom: 1px solid rgba(148, 163, 184, 0.22);
    box-shadow: 0 10px 30px rgba(15, 23, 42, 0.05);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

.navbar-modern .navbar-brand {
    color: #0f172a !important;
    font-size: 1.35rem;
    letter-spacing: -0.04em;
}

.navbar-modern .nav-link {
    color: #334155 !important;
    font-weight: 600;
    padding: 0.7rem 0.9rem !important;
    border-radius: 0.75rem;
    transition: all 0.2s ease-in-out;
}

.navbar-modern .nav-link:hover,
.navbar-modern .nav-link:focus {
    color: #0f172a !important;
    background: #f8fafc;
}

.navbar-modern .navbar-toggler {
    border: 1px solid rgba(148, 163, 184, 0.5);
    border-radius: 0.75rem;
}

.navbar-modern .navbar-toggler:focus {
    box-shadow: 0 0 0 0.2rem rgba(14, 165, 233, 0.15);
}

.navbar-modern .navbar-toggler-icon {
    filter: invert(17%) sepia(15%) saturate(1230%) hue-rotate(180deg) brightness(95%) contrast(92%);
}

.btn-signup {
    background: linear-gradient(135deg, #0ea5e9, #14b8a6);
    color: #ffffff !important;
    border: none;
    border-radius: 999px;
    font-weight: 700;
    padding: 0.55rem 1rem;
    box-shadow: 0 8px 18px rgba(20, 184, 166, 0.22);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.btn-signup:hover,
.btn-signup:focus {
    color: #ffffff !important;
    transform: translateY(-1px);
    box-shadow: 0 12px 24px rgba(14, 165, 233, 0.24);
}

.btn-logout {
    background: #f8fafc;
    color: #0f172a !important;
    border: 1px solid rgba(148, 163, 184, 0.4);
    border-radius: 999px;
    font-weight: 600;
    padding: 0.55rem 1rem;
    transition: all 0.2s ease-in-out;
}

.btn-logout:hover,
.btn-logout:focus {
    background: #eef2ff;
    color: #0f172a !important;
    border-color: rgba(99, 102, 241, 0.35);
}

.category-section {
    padding-top: 2.25rem;
}

.section-header {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 0.35rem;
}

.section-header.text-center {
    align-items: center;
}

.eyebrow {
    display: inline-flex;
    align-items: center;
    padding: 0.35rem 0.75rem;
    border-radius: 999px;
    background: rgba(14, 165, 233, 0.1);
    color: #0369a1;
    font-size: 0.72rem;
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.section-header h3 {
    margin: 0;
    font-size: clamp(1.8rem, 2vw, 2.5rem);
    font-weight: 800;
    letter-spacing: -0.05em;
    color: #0f172a;
}

.category-card {
    background: linear-gradient(180deg, #ffffff 0%, #f8fafc 100%);
    border: 1px solid rgba(148, 163, 184, 0.2);
    border-radius: 1.25rem;
    padding: 1.4rem 1rem;
    box-shadow: 0 12px 28px rgba(15, 23, 42, 0.06);
    transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 150px;
}

.category-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 18px 30px rgba(15, 23, 42, 0.09);
    border-color: rgba(14, 165, 233, 0.25);
}

.category-icon {
    width: 62px;
    height: 62px;
    border-radius: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 0.9rem;
    font-size: 1.7rem;
    color: #ffffff;
}

.category-icon.tech {
    background: linear-gradient(135deg, #0ea5e9, #3b82f6);
}

.category-icon.academics {
    background: linear-gradient(135deg, #8b5cf6, #6366f1);
}

.category-icon.business {
    background: linear-gradient(135deg, #f59e0b, #f97316);
}

.category-icon.skills {
    background: linear-gradient(135deg, #10b981, #14b8a6);
}

.category-card h5 {
    margin: 0;
    font-size: 1.05rem;
    font-weight: 700;
    color: #0f172a;
}

.top-trainers-section {
    background: linear-gradient(180deg, #f8fafc 0%, #ffffff 100%);
}

.course-card {
    background: #ffffff;
    border: 1px solid rgba(148, 163, 184, 0.2);
    border-radius: 1.25rem;
    overflow: hidden;
    box-shadow: 0 12px 28px rgba(15, 23, 42, 0.06);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
    height: 100%;
}

.course-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 18px 34px rgba(15, 23, 42, 0.1);
}

.course-image {
    width: 100%;
    height: 220px;
    object-fit: cover;
    display: block;
}

.course-body {
    padding: 1rem 1rem 1.15rem;
}

.course-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.7rem;
    gap: 0.75rem;
}

.course-tag {
    display: inline-flex;
    align-items: center;
    padding: 0.35rem 0.6rem;
    border-radius: 999px;
    background: rgba(14, 165, 233, 0.1);
    color: #0369a1;
    font-size: 0.7rem;
    font-weight: 700;
}

.course-price {
    font-size: 0.9rem;
    font-weight: 800;
    color: #0f172a;
}

.course-title {
    margin: 0 0 0.5rem;
    font-size: 1.08rem;
    font-weight: 700;
    line-height: 1.45;
    color: #0f172a;
}

.course-author {
    margin: 0 0 0.9rem;
    color: #64748b;
    font-size: 0.92rem;
}

.course-details {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 0.75rem;
    padding-top: 0.8rem;
    border-top: 1px solid rgba(148, 163, 184, 0.22);
    color: #475569;
    font-size: 0.82rem;
    font-weight: 600;
}

@media (max-width: 767.98px) {
    .section-header {
        align-items: center;
        text-align: center;
    }

    .category-card {
        min-height: 130px;
    }

    .course-image {
        height: 210px;
    }
}