:root {
    --primary: #0046ad;
    --primary-dark: #003a92;
    --secondary: #f3c613;
    --dark: #1e1f23;
    --light: #f7f7f7;
    --success: #198754;
    --gradient: linear-gradient(135deg, #0046ad 0%, #002a66 100%);
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--light);
    color: #333;
}

.course-header {
    background: var(--gradient);
    color: white;
    padding: 60px 0;
    position: relative;
    overflow: hidden;
}

.course-header::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1440 320"><path fill="%23002a66" fill-opacity="0.2" d="M0,224L48,213.3C96,203,192,181,288,181.3C384,181,480,203,576,202.7C672,203,768,181,864,170.7C960,160,1056,160,1152,170.7C1248,181,1344,203,1392,213.3L1440,224L1440,320L1392,320C1344,320,1248,320,1152,320C1056,320,960,320,864,320C768,320,672,320,576,320C480,320,384,320,288,320C192,320,96,320,48,320L0,320Z"></path></svg>');
    background-size: cover;
    background-position: bottom;
}

.course-header .container {
    position: relative;
    z-index: 1;
}

.course-header h1 {
    font-size: 2.8rem;
    font-weight: 800;
    line-height: 1.2;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.course-header .subtitle {
    font-size: 1.3rem;
    opacity: 0.9;
    line-height: 1.6;
}

.course-header .price-card {
    background: rgba(255, 255, 255, 0.15);
    backdrop-filter: blur(10px);
    border-radius: 16px;
    padding: 25px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.2);
    border: 1px solid rgba(255, 255, 255, 0.18);
}

.course-header .price {
    font-size: 2.2rem;
    font-weight: 800;
}

.course-header .original-price {
    font-size: 1.4rem;
    text-decoration: line-through;
    opacity: 0.7;
}

.course-header .buy-btn {
    background-color: var(--secondary);
    border: none;
    color: #000;
    font-weight: bold;
    padding: 12px 30px;
    border-radius: 50px;
    font-size: 1.1rem;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(243, 198, 19, 0.3);
}

.course-header .buy-btn:hover {
    background-color: #e0b411;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(243, 198, 19, 0.4);
}

.subscription-btn{
    color: #fff !important;
}

.rating {
    color: var(--secondary);
}

.badge {
    font-size: 0.9rem;
}

.what-learn {
    background-color: white;
    padding: 30px;
    border-radius: 16px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
    border-left: 5px solid var(--primary);
}

.what-learn h2 {
    color: var(--primary);
    margin-bottom: 25px;
    font-weight: 700;
}

.what-learn ul {
    list-style: none;
    padding: 0;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 15px;
}

.what-learn li {
    position: relative;
    padding-left: 35px;
    margin-bottom: 15px;
    line-height: 1.6;
}

.what-learn li::before {
    content: "\2714";
    position: absolute;
    left: 0;
    color: var(--primary);
    font-weight: bold;
    font-size: 1.2rem;
    background: rgba(0, 70, 173, 0.1);
    width: 26px;
    height: 26px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.related-topics {
    background: var(--gradient);
    padding: 30px;
    border-radius: 16px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease-in-out;
    margin-bottom: 30px;
}

.related-topics:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.15);
}

.related-topics h4 {
    color: white;
    font-weight: 700;
    margin-bottom: 25px;
}

.topic-pill {
    display: inline-block;
    padding: 12px 20px;
    background: rgba(255, 255, 255, 0.15);
    color: white;
    border-radius: 50px;
    font-weight: 500;
    text-decoration: none;
    transition: all 0.3s ease;
    margin: 5px;
    border: 1px solid rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(5px);
}

.topic-pill:hover {
    background: white;
    color: var(--primary);
    transform: translateY(-3px);
    box-shadow: 0 5px 15px rgba(255, 255, 255, 0.2);
}

.coding-exercises {
    background-color: white;
    padding: 30px;
    border-radius: 16px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
    margin-bottom: 30px;
    border-top: 5px solid var(--secondary);
}

.coding-exercises h2 {
    color: var(--dark);
    font-weight: 700;
    margin-bottom: 20px;
}

.coding-exercises img {
    border-radius: 12px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease;
}

.coding-exercises img:hover {
    transform: scale(1.02);
}

.course-content {
    margin-bottom: 40px;
}

.curriculum h2 {
    color: var(--primary);
    font-weight: 800;
    margin-bottom: 30px;
    position: relative;
    padding-bottom: 15px;
}

.curriculum h2::after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 100px;
    height: 4px;
    background: var(--secondary);
    border-radius: 2px;
}

.accordion-item {
    border: none;
    margin-bottom: 15px;
    border-radius: 12px !important;
    overflow: hidden;
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.08);
}

.accordion-button {
    background-color: white;
    color: var(--dark);
    font-weight: 600;
    padding: 20px;
    border: none;
    box-shadow: none;
}

.accordion-button:not(.collapsed) {
    background-color: var(--primary);
    color: white;
}

.accordion-button::after {
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='%230046ad'%3e%3cpath fill-rule='evenodd' d='M1.646 4.646a.5.5 0 0 1 .708 0L8 10.293l5.646-5.647a.5.5 0 0 1 .708.708l-6 6a.5.5 0 0 1-.708 0l-6-6a.5.5 0 0 1 0-.708z'/%3e%3c/svg%3e");
}

.accordion-button:not(.collapsed)::after {
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='%23ffffff'%3e%3cpath fill-rule='evenodd' d='M1.646 4.646a.5.5 0 0 1 .708 0L8 10.293l5.646-5.647a.5.5 0 0 1 .708.708l-6 6a.5.5 0 0 1-.708 0l-6-6a.5.5 0 0 1 0-.708z'/%3e%3c/svg%3e");
}

.accordion-body {
    padding: 25px;
    background-color: #f9fafc;
}

.accordion-body ul {
    margin-bottom: 15px;
}

.accordion-body li {
    margin-bottom: 8px;
    position: relative;
    padding-left: 20px;
}

.accordion-body li::before {
    content: "•";
    color: var(--primary);
    font-weight: bold;
    position: absolute;
    left: 0;
}

.subscription-section {
    background-color: white;
    padding: 25px;
    border-radius: 16px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
    text-align: center;
    position: sticky;
    top: 20px;
    border: 1px solid #eaeaea;
}

.subscription-section img {
    border-radius: 12px;
    margin-bottom: 20px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.subscription-section p {
    margin: 15px 0;
    line-height: 1.6;
}

.price-off {
    color: var(--primary);
    font-weight: 800;
    font-size: 1.8rem;
}

.original-price-off {
    text-decoration: line-through;
    color: #999;
    font-size: 1.2rem;
}

.subscription-btn {
    background: var(--gradient);
    color: white;
    font-weight: bold;
    width: 100%;
    margin-bottom: 10px;
    padding: 15px;
    border-radius: 50px;
    border: none;
    font-size: 1.1rem;
    transition: all 0.3s ease;
    box-shadow: 0 5px 15px rgba(0, 70, 173, 0.3);
}

.subscription-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(0, 70, 173, 0.4);
}

@keyframes blinkAnimation {
    0% {
        opacity: 1;
    }

    50% {
        opacity: 0.7;
    }

    100% {
        opacity: 1;
    }
}

.blink {
    animation: blinkAnimation 1.5s infinite;
    color: #dc3545;
    font-weight: 700;
}

.stats-section {
    background: white;
    border-radius: 16px;
    padding: 30px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
    margin: 40px 0;
}

.stat-item {
    text-align: center;
    padding: 20px;
}

.stat-number {
    font-size: 2rem;
    font-weight: 800;
    color: var(--primary);
    display: block;
}

.stat-label {
    font-size: 1rem;
    color: #666;
}

.author-info h5 {
    margin: 0;
    font-size: 1.1rem;
}

.author-info p {
    margin: 0;
    color: #666;
    font-size: 0.9rem;
}

@media (max-width: 768px) {
    .course-header h1 {
        font-size: 2.2rem;
    }

    .course-header .subtitle {
        font-size: 1.1rem;
    }

    .what-learn ul {
        grid-template-columns: 1fr;
    }

    .topic-pill {
        padding: 10px 15px;
        font-size: 0.9rem;
    }

    .stat-number {
        font-size: 1.5rem;
    }
}