:root {
        --primary-bg: #ffffff;
        --secondary-bg: #f8fafd;
        --accent-red: #E03B3B;
        --accent-dark: #1a2639;
        --text-primary: #2d3a4f;
        --text-secondary: #5e6f8d;
        --border-light: #eef2f6;
        --shadow-soft: 0 10px 30px -15px rgba(0,0,0,0.1), 0 5px 15px -10px rgba(224,59,59,0.1);
        --shadow-hover: 0 20px 35px -18px rgba(224,59,59,0.2);
        --transition: all 0.25s ease;
    }
    
    body {
        font-family: 'Inter', sans-serif;
        background: var(--secondary-bg);
        color: var(--text-primary);
        line-height: 1.5;
    }
    
    h1, h2, h3, h4, h5 {
        font-family: 'Plus Jakarta Sans', sans-serif;
        font-weight: 600;
        letter-spacing: -0.02em;
    }
    
    /* --- Clean Header --- */
    .course-header {
        background: linear-gradient(115deg, #1a2639 0%, #2c3a55 100%);
        padding: 200px 0 100px;
        position: relative;
        margin-bottom: -50px;
    }
    @keyframes flicker {
        0% { opacity: 1; transform: scale(1); }
        50% { opacity: 0.8; transform: scale(1.1); }
        100% { opacity: 1; transform: scale(1); }
    }
    
    .header-badge {
        background: rgba(224,59,59,0.15);
        backdrop-filter: blur(4px);
        border: 1px solid rgba(224,59,59,0.3);
        color: white;
        padding: 5px 16px;
        border-radius: 40px;
        display: inline-flex;
        align-items: center;
        gap: 8px;
        font-size: 0.85rem;
        font-weight: 500;
        margin-bottom: 20px;
    }
    
    .header-badge i {
        color: var(--accent-red);
        font-size: 0.75rem;
    }
    
    .course-header h1 {
        color: white;
        font-size: 2.8rem;
        font-weight: 700;
        margin-bottom: 15px;
        line-height: 1.2;
    }
    
    .course-header .lead {
        color: rgba(255,255,255,0.85);
        font-size: 1.1rem;
        max-width: 600px;
        margin-bottom: 25px;
    }
    
    .header-meta {
        display: flex;
        gap: 25px;
        color: rgba(255,255,255,0.8);
        font-size: 0.95rem;
    }
    
    .header-meta i {
        color: var(--accent-red);
        margin-right: 6px;
    }
    
    /* --- Main Content Area --- */
    .content-wrapper {
        position: relative;
        z-index: 10;
        padding-bottom: 60px;
    }
    
    /* Left Column Cards */
    .card-modern {
        background: white;
        border-radius: 24px;
        padding: 28px;
        margin-bottom: 24px;
        box-shadow: var(--shadow-soft);
        border: 1px solid var(--border-light);
        transition: var(--transition);
    }
    
    .card-modern:hover {
        box-shadow: var(--shadow-hover);
        transform: translateY(-3px);
    }
    
    .card-label {
        display: inline-block;
        background: var(--accent-dark);
        color: white;
        padding: 4px 14px;
        border-radius: 30px;
        font-size: 0.7rem;
        font-weight: 600;
        text-transform: uppercase;
        letter-spacing: 0.5px;
        margin-bottom: 18px;
    }
    
    .card-title {
        font-size: 1.5rem;
        color: var(--accent-dark);
        margin-bottom: 18px;
        font-weight: 700;
    }
    
    /* Video Container */
    .video-box {
        border-radius: 18px;
        overflow: hidden;
        box-shadow: 0 12px 25px -15px var(--accent-red);
        margin-bottom: 20px;
        border: 1px solid rgba(224,59,59,0.2);
    }
    
    /* Feature Grid */
    .features-grid {
        display: grid;
        grid-template-columns: repeat(2, 1fr);
        gap: 15px;
        margin: 20px 0;
    }
    
    .feature-item {
        background: var(--secondary-bg);
        padding: 20px 16px;
        border-radius: 18px;
        border: 1px solid var(--border-light);
        transition: var(--transition);
    }
    
    .feature-item:hover {
        background: white;
        border-color: var(--accent-red);
    }
    
    .feature-item i {
        color: var(--accent-red);
        font-size: 1.3rem;
        margin-bottom: 10px;
        background: white;
        padding: 8px;
        border-radius: 14px;
        box-shadow: 0 5px 12px -8px var(--accent-red);
    }
    
    .feature-item h5 {
        font-size: 1rem;
        margin-bottom: 4px;
    }
    
    .feature-item p {
        font-size: 0.8rem;
        color: var(--text-secondary);
        margin: 0;
    }
    
    /* Demo Grid */
    .demo-grid {
        display: grid;
        grid-template-columns: repeat(2, 1fr);
        gap: 18px;
    }
    
    .demo-card {
        background: var(--secondary-bg);
        border-radius: 16px;
        overflow: hidden;
        border: 1px solid var(--border-light);
        transition: var(--transition);
    }
    
    .demo-card:hover {
        transform: translateY(-4px);
        border-color: var(--accent-red);
    }
    
    .demo-card .ratio {
        border-bottom: 2px solid var(--accent-red);
    }
    
    .demo-card p {
        padding: 12px;
        font-weight: 500;
        font-size: 0.9rem;
        margin: 0;
        color: var(--accent-dark);
    }
    
    /* Images */
    .img-modern {
        border-radius: 18px;
        border: 1px solid var(--border-light);
        width: 100%;
        transition: var(--transition);
    }
    
    .img-modern:hover {
        border-color: var(--accent-red);
    }
    
    /* --- Right Sidebar - Enrollment Card --- */
    

    .enroll-sidebar {
        position: sticky !important;
        top: 90px;
        align-self: flex-start;
        transition: var(--transition);
    }
    
    .row {
        align-items: flex-start;
    }
    
    .enroll-card {
        background: white;
        border-radius: 28px;
        padding: 28px;
        box-shadow: 0 20px 40px -20px rgba(0,0,0,0.2);
        border: 1px solid var(--border-light);
        transition: var(--transition);
    }
    
    .enroll-card:hover {
        box-shadow: 0 25px 45px -22px var(--accent-red);
    }
    
    .enroll-badge {
        background: var(--accent-red);
        color: white;
        padding: 4px 14px;
        border-radius: 40px;
        font-size: 0.75rem;
        font-weight: 600;
        display: inline-block;
        margin-bottom: 15px;
    }
    
    .enroll-card h3 {
        font-size: 1.6rem;
        color: var(--accent-dark);
        margin-bottom: 5px;
    }
    
    .price-section {
        margin: 20px 0 25px;
        display: flex;
        align-items: baseline;
        gap: 12px;
        flex-wrap: wrap;
    }
    
    .current-price {
        font-size: 2.2rem;
        font-weight: 700;
        color: var(--accent-dark);
    }
    
    .old-price {
        text-decoration: line-through;
        color: var(--text-secondary);
        font-size: 1.1rem;
    }
    
    .discount {
        background: #fee9e9;
        color: var(--accent-red);
        padding: 3px 10px;
        border-radius: 30px;
        font-size: 0.8rem;
        font-weight: 600;
    }
    
    .btn-enroll {
        background: var(--accent-red);
        color: white;
        width: 100%;
        padding: 14px;
        border-radius: 60px;
        font-weight: 600;
        font-size: 1rem;
        border: none;
        display: flex;
        align-items: center;
        justify-content: center;
        gap: 10px;
        margin-bottom: 12px;
        transition: var(--transition);
    }
    
    .btn-enroll:hover {
        background: var(--accent-dark);
        color: white;
        transform: translateY(-2px);
    }
    
    .btn-scholar {
        background: transparent;
        color: var(--accent-dark);
        width: 100%;
        padding: 12px;
        border-radius: 60px;
        font-weight: 500;
        border: 2px solid var(--accent-dark);
        display: block;
        text-align: center;
        text-decoration: none;
        font-size: 0.95rem;
        transition: var(--transition);
        margin-bottom: 20px;
    }
    
    .btn-scholar:hover {
        background: var(--accent-dark);
        color: white;
    }
    
    .feature-list {
        list-style: none;
        padding: 0;
        margin: 20px 0;
    }
    
    .feature-list li {
        display: flex;
        align-items: center;
        gap: 12px;
        margin-bottom: 14px;
        color: var(--text-primary);
        font-size: 0.95rem;
    }
    
    .feature-list i {
        color: var(--accent-red);
        font-size: 0.9rem;
        width: 18px;
    }
    
    .contact-box {
        background: var(--secondary-bg);
        border-radius: 18px;
        padding: 16px;
        text-align: center;
        border: 1px solid var(--border-light);
    }
    
    .contact-box small {
        color: var(--text-secondary);
        font-size: 0.75rem;
    }
    
    .contact-box a {
        color: var(--accent-dark);
        font-size: 1.1rem;
        font-weight: 600;
        text-decoration: none;
        display: flex;
        align-items: center;
        justify-content: center;
        gap: 8px;
        margin-top: 5px;
    }
    
    .contact-box i {
        color: var(--accent-red);
        font-size: 1rem;
    }
    
    /* FAQ Accordion */
    .accordion-modern {
        background: white;
        border-radius: 20px;
        overflow: hidden;
    }
    
    .accordion-item {
        border: none;
        border-bottom: 1px solid var(--border-light);
    }
    
    .accordion-button {
        padding: 18px 20px;
        font-weight: 600;
        color: var(--accent-dark);
        background: white;
    }
    
    .accordion-button:not(.collapsed) {
        background: var(--secondary-bg);
        color: var(--accent-red);
    }
    
    .accordion-button:focus {
        box-shadow: none;
    }
    
    .accordion-body {
        padding: 18px 20px;
        color: var(--text-secondary);
        background: white;
    }
    
    /* Responsive */
    @media (max-width: 991px) {
        .course-header h1 {
            font-size: 2.2rem;
        }
        
        .enroll-sidebar {
            position: static !important;
            margin-top: 30px;
        }
        
        .features-grid {
            grid-template-columns: 1fr;
        }
        
        .demo-grid {
            grid-template-columns: 1fr;
        }
    }
    
    @media (max-width: 576px) {
        .card-modern {
            padding: 20px;
        }
        
        .course-header {
            padding: 60px 0 80px;
        }
    }