:root {
    --primary-color: #4f46e5;
    --primary-hover: #4338ca;
    --secondary-color: #f59e0b;
    --dark-bg: #0f172a;
    --light-bg: #f8fafc;
    --text-main: #1e293b;
    --text-muted: #64748b;
    --white: #ffffff;
    --card-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --card-shadow-hover: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--light-bg);
    color: var(--text-main);
}

/* Navbar Tuning */
.navbar {
    padding: 1rem 0;
    transition: all 0.3s ease;
    background: var(--white);
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}

.navbar-brand {
    font-weight: 800;
    font-size: 1.5rem;
    color: var(--primary-color) !important;
}

.nav-link {
    font-weight: 500;
    color: var(--text-main) !important;
    padding: 0.5rem 1rem !important;
    transition: color 0.3s ease;
}

.nav-link:hover {
    color: var(--primary-color) !important;
}

/* Hero Section */
.hero-section {
    padding: 100px 0;
    background: linear-gradient(135deg, #4f46e5 0%, #7c3aed 100%);
    position: relative;
    overflow: hidden;
}

.hero-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url("data:image/svg+xml,%3Csvg width='100' height='100' viewBox='0 0 100 100' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M11 18c3.866 0 7-3.134 7-7s-3.134-7-7-7-7 3.134-7 7 3.134 7 7 7zm48 25c3.866 0 7-3.134 7-7s-3.134-7-7-7-7 3.134-7 7 3.134 7 7 7zm-43-7c1.657 0 3-1.343 3-3s-1.343-3-3-3-3 1.343-3 3 1.343 3 3 3zm63 31c1.657 0 3-1.343 3-3s-1.343-3-3-3-3 1.343-3 3 1.343 3 3 3zM34 90c1.657 0 3-1.343 3-3s-1.343-3-3-3-3 1.343-3 3 1.343 3 3 3zm56-76c1.657 0 3-1.343 3-3s-1.343-3-3-3-3 1.343-3 3 1.343 3 3 3zM12 86c2.21 0 4-1.79 4-4s-1.79-4-4-4-4 1.79-4 4 1.79 4 4 4zm28-65c2.21 0 4-1.79 4-4s-1.79-4-4-4-4 1.79-4 4 1.79 4 4 4zm23-11c2.76 0 5-2.24 5-5s-2.24-5-5-5-5 2.24-5 5 2.24 5 5 5zm-6 60c2.21 0 4-1.79 4-4s-1.79-4-4-4-4 1.79-4 4 1.79 4 4 4zm29 22c2.76 0 5-2.24 5-5s-2.24-5-5-5-5 2.24-5 5 2.24 5 5 5zM32 35c2.21 0 4-1.79 4-4s-1.79-4-4-4-4 1.79-4 4 1.79 4 4 4zm57-13c2.21 0 4-1.79 4-4s-1.79-4-4-4-4 1.79-4 4 1.79 4 4 4zM58 58c2.21 0 4-1.79 4-4s-1.79-4-4-4-4 1.79-4 4 1.79 4 4 4z' fill='%23ffffff' fill-opacity='0.05' fill-rule='evenodd'/%3E%3C/svg%3E");
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 800;
    line-height: 1.2;
    color: var(--white);
    margin-bottom: 1.5rem;
}

.search-container {
    background: var(--white);
    padding: 0.5rem;
    border-radius: 50px;
    display: flex;
    max-width: 600px;
    margin-top: 2rem;
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
}

.search-input {
    border: none;
    padding: 0.8rem 1.5rem;
    flex-grow: 1;
    border-radius: 50px;
}

.search-input:focus {
    outline: none;
}

.search-btn {
    border-radius: 50px !important;
    padding: 0.8rem 2rem !important;
}

/* Cards Styling */
.course-card {
    border: none;
    background: var(--white);
    border-radius: 16px;
    overflow: hidden;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: var(--card-shadow);
    height: 100%;
}

.course-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--card-shadow-hover);
}

.course-img-wrapper {
    position: relative;
    padding-top: 56.25%; /* 16:9 Aspect Ratio */
    overflow: hidden;
}

.course-img {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
}

.course-card:hover .course-img {
    transform: scale(1.1);
}

.course-badge {
    position: absolute;
    top: 1rem;
    left: 1rem;
    padding: 0.4rem 0.8rem;
    background: var(--primary-color);
    color: white;
    border-radius: 6px;
    font-size: 0.75rem;
    font-weight: 600;
}

.course-body {
    padding: 1.5rem;
}

.course-title {
    font-weight: 700;
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
    color: var(--text-main);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    min-height: 2.8rem;
}

.teacher-info {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-bottom: 1rem;
}

.rating {
    color: var(--secondary-color);
    font-size: 0.85rem;
    margin-bottom: 1rem;
}

.course-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-top: 1px solid #f1f5f9;
    padding-top: 1rem;
}

.course-price {
    font-weight: 800;
    font-size: 1.25rem;
    color: var(--primary-color);
}

/* Section Header */
.section-header {
    margin-bottom: 3rem;
    text-align: center;
}

.section-subtitle {
    color: var(--primary-color);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 2px;
    font-size: 0.85rem;
    margin-bottom: 0.5rem;
    display: block;
}

.section-title {
    font-weight: 800;
    font-size: 2.5rem;
}

/* Feature Icon */
.feature-box {
    padding: 2rem;
    background: var(--white);
    border-radius: 16px;
    text-align: center;
    transition: all 0.3s ease;
    height: 100%;
}

.feature-box:hover {
    background: var(--primary-color);
}

.feature-box:hover * {
    color: var(--white) !important;
}

.feature-icon {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 1.5rem;
}

/* Stats Counter */
.stat-box {
    text-align: center;
    padding: 2rem;
}

.stat-number {
    font-size: 3rem;
    font-weight: 800;
    color: var(--primary-color);
}

.stat-label {
    font-weight: 600;
    color: var(--text-muted);
}

/* Testimonials */
.testimonial-card {
    background: var(--white);
    padding: 2rem;
    border-radius: 16px;
    box-shadow: var(--card-shadow);
    margin: 1rem;
}

.student-img {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    object-fit: cover;
    margin-bottom: 1rem;
}

/* Sidebar Details */
.sticky-sidebar {
    position: sticky;
    top: 100px;
}

.detail-card {
    border: none;
    border-radius: 16px;
    box-shadow: var(--card-shadow-hover);
    overflow: hidden;
}

/* Footer Styling */
footer {
    background: var(--dark-bg);
    color: #94a3b8;
    padding-top: 80px;
}

footer .footer-title {
    color: var(--white);
    font-weight: 700;
    margin-bottom: 1.5rem;
}

footer .footer-link {
    color: #94a3b8;
    text-decoration: none;
    display: block;
    margin-bottom: 0.8rem;
    transition: color 0.3s ease;
}

footer .footer-link:hover {
    color: var(--primary-color);
}

.newsletter-form {
    background: rgba(255,255,255,0.05);
    padding: 0.5rem;
    border-radius: 50px;
    display: flex;
}

.newsletter-input {
    background: transparent;
    border: none;
    color: white;
    padding: 0.5rem 1rem;
    flex-grow: 1;
}

.newsletter-input:focus {
    outline: none;
}

/* Animations */
.animate-hover-lift:hover {
    transform: translateY(-5px);
}

.btn-primary {
    background-color: var(--primary-color);
    border-color: var(--primary-color);
    padding: 0.8rem 1.5rem;
    border-radius: 10px;
    font-weight: 600;
    transition: all 0.3s ease;
}

.btn-primary:hover {
    background-color: var(--primary-hover);
    border-color: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(79, 70, 229, 0.4);
}

/* Filters */
.filter-card {
    border: none;
    border-radius: 12px;
    background: white;
    padding: 1.5rem;
    box-shadow: var(--card-shadow);
}

.filter-title {
    font-weight: 700;
    margin-bottom: 1.2rem;
    font-size: 1rem;
}

/* Skeleton Loaders (Optional improvement) */
@keyframes loading {
    0% { background-position: -200px 0; }
    100% { background-position: calc(200px + 100%) 0; }
}

/* Responsive fixes */
@media (max-width: 991.98px) {
    .hero-title {
        font-size: 2.5rem;
    }
}