/* Premium Course Details Styles */

body {
    background-color: #f8f9fb;
    /* Light background for contrast */
}

/* --- Hero Section --- */
.course-hero {
    background: linear-gradient(135deg, #1a237e 0%, #0d47a1 100%);
    /* Deep Blue Brand Gradient */
    color: white;
    padding: 40px 0 60px;
    position: relative;
}

.hero-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: grid;
    grid-template-columns: 1.8fr 1fr;
    /* Space for content vs sidebar placeholder */
    gap: 40px;
}

.hero-breadcrumb {
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.8);
    margin-bottom: 15px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.hero-breadcrumb a {
    color: #ffd700;
    /* Gold */
    font-weight: 500;
}

.course-title {
    font-size: 2.5rem;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 20px;
    letter-spacing: -0.5px;
    color: #ffd700;
    /* Gold color for best appearance on dark blue */
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
    /* Subtle shadow for lift */
}

.course-meta-header {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    font-size: 0.95rem;
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: 30px;
}

.meta-rating {
    color: #f4c150;
    font-weight: 600;
}

.meta-stats {
    display: flex;
    align-items: center;
    gap: 6px;
}

/* --- Main Layout Grid --- */
.course-page-container {
    max-width: 1200px;
    margin: -50px auto 40px;
    /* Pull up to overlap hero */
    padding: 0 20px;
    display: grid;
    grid-template-columns: 2fr 1fr;
    /* Main Content vs Sidebar */
    gap: 40px;
    position: relative;
    align-items: start;
}

/* --- Sticky Sidebar (Right) --- */
.course-sidebar-wrapper {
    position: sticky;
    top: 20px;
    /* Stick to top on scroll */
    z-index: 100;
}

.purchase-card {
    background: white;
    border-radius: var(--radius-lg);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    overflow: hidden;
    border: 1px solid rgba(0, 0, 0, 0.05);
}

.video-preview {
    width: 100%;
    aspect-ratio: 16/9;
    background: black;
    position: relative;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
}

.video-play-btn {
    width: 60px;
    height: 60px;
    background: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: var(--primary-color);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
    transition: transform 0.3s;
}

.video-preview:hover .video-play-btn {
    transform: scale(1.1);
}

.card-content {
    padding: 25px;
}

.price-block {
    display: flex;
    align-items: baseline;
    gap: 12px;
    margin-bottom: 20px;
}

.current-price {
    font-size: 2.2rem;
    font-weight: 800;
    color: #333;
}

.old-price {
    color: #888;
    text-decoration: line-through;
    font-size: 1.1rem;
}

.discount-tag {
    color: #4CAF50;
    font-weight: 700;
}

.join-btn {
    width: 100%;
    padding: 16px;
    background: var(--primary-color);
    /* Fallback */
    background: linear-gradient(135deg, #FF6B6B 0%, #EE5253 100%);
    /* Attention Grabbing Red/Pink */
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1.1rem;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.3s;
    box-shadow: 0 4px 12px rgba(238, 82, 83, 0.3);
}

.join-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 16px rgba(238, 82, 83, 0.4);
}

.guarantee-text {
    text-align: center;
    font-size: 0.8rem;
    color: #777;
    margin-top: 15px;
}

.features-list {
    margin-top: 25px;
    list-style: none;
}

.feature-item {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 12px;
    font-size: 0.95rem;
    color: #555;
}

.feature-item i {
    width: 20px;
    text-align: center;
}

/* --- Main Content (Left) --- */
.content-box {
    background: white;
    border: 1px solid #eee;
    padding: 30px;
    border-radius: var(--radius-md);
    margin-bottom: 30px;
}

.section-title {
    font-size: 1.4rem;
    font-weight: 700;
    color: #222;
    margin-bottom: 20px;
}

/* Learning Objectives Box */
.learning-box {
    border: 1px solid #ddd;
    background-color: #fdfdfd;
}

.learning-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
}

.learn-item {
    display: flex;
    gap: 10px;
    font-size: 0.95rem;
    color: #444;
}

.learn-item i {
    color: #4CAF50;
    margin-top: 3px;
}

/* Tabs */
.course-tabs {
    display: flex;
    gap: 0;
    border-bottom: 1px solid #ddd;
    margin-bottom: 30px;
    background: white;
    padding: 0 10px;
    border-radius: var(--radius-md) var(--radius-md) 0 0;
}

.tab-link {
    padding: 18px 25px;
    font-weight: 600;
    color: #666;
    background: none;
    border: none;
    cursor: pointer;
    border-bottom: 3px solid transparent;
    transition: all 0.3s;
    font-size: 1rem;
}

.tab-link.active {
    color: var(--primary-color);
    border-bottom-color: var(--primary-color);
}

.description-text {
    line-height: 1.8;
    color: #333;
}

.description-text p {
    margin-bottom: 15px;
}

/* Default State: Hide Mobile Thumbnail on Desktop */
.mobile-thumbnail {
    display: none;
}

/* Responsive */
/* Responsive */
@media (max-width: 767px) {

    .mobile-thumbnail {
        display: block !important;
        width: 100%;
        margin-bottom: 20px;
    }

    /* Fixed Sidebar Stacking */
    .course-page-container {
        display: flex;
        flex-direction: column;
        margin-top: 0;
        padding: 0 15px;
        gap: 30px;
    }

    .course-sidebar-wrapper {
        position: static;
        width: 100%;
        order: -1;
        /* Show pricing card FIRST on mobile */
        margin-bottom: 0;
    }

    .purchase-card {
        box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
    }

    .hero-content {
        display: flex;
        flex-direction: column;
        text-align: center;
        gap: 20px;
    }

    .course-title {
        font-size: 1.8rem;
    }

    .hero-breadcrumb {
        justify-content: center;
    }

    .course-meta-header {
        justify-content: center;
        gap: 15px;
    }

    /* Tabs Scrollable on Mobile */
    .course-tabs {
        overflow-x: auto;
        white-space: nowrap;
        padding-bottom: 0;
        margin-bottom: 20px;
        /* Hide scrollbar */
        scrollbar-width: none;
    }

    .course-tabs::-webkit-scrollbar {
        display: none;
    }

    .learning-grid {
        grid-template-columns: 1fr;
        /* Stack learning items */
    }
}