:root {
    --primary-blue: #0066CC;
    --primary-dark: #1A365D;
    --primary-light: #4D94FF;
    --accent-teal: #00B4D8;
    --accent-green: #00CC88;
    --accent-purple: #8A2BE2;
    --light-gray: #F8FAFC;
    --medium-gray: #E2E8F0;
    --dark-gray: #4A5568;
    --text-dark: #2D3748;
    --text-light: #718096;
    --gradient-primary: linear-gradient(135deg, var(--primary-blue) 0%, var(--accent-teal) 100%);
    --gradient-secondary: linear-gradient(135deg, var(--accent-purple) 0%, var(--primary-light) 100%);
    --shadow-light: 0 10px 30px rgba(0, 102, 204, 0.08);
    --shadow-medium: 0 15px 40px rgba(0, 0, 0, 0.1);
    --shadow-large: 0 20px 50px rgba(0, 0, 0, 0.15);
    --border-radius: 16px;
    --border-radius-small: 10px;
}

* {
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background-color: var(--light-gray);
    color: var(--text-dark);
    line-height: 1.6;
    margin: 0;
    padding: 0;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4, h5, h6 {
    font-family: 'Poppins', -apple-system, BlinkMacSystemFont, sans-serif;
    font-weight: 600;
    margin-top: 0;
}

.container {
    padding-left: 15px;
    padding-right: 15px;
}

/* Header */
.page-header {
    background: white;
    padding: 40px 0 30px;
    margin-bottom: 40px;
    border-bottom: 1px solid var(--medium-gray);
}

.page-title {
    font-size: 42px;
    font-weight: 700;
    color: var(--primary-dark);
    margin-bottom: 15px;
    text-align: center;
}

.page-subtitle {
    font-size: 18px;
    color: var(--text-light);
    text-align: center;
    max-width: 700px;
    margin: 0 auto;
}

/* Courses Grid */
.courses-grid {
    padding: 0 15px 60px;
}

.course-card {
    background: white;
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--shadow-medium);
    margin-bottom: 30px;
    transition: transform 0.3s, box-shadow 0.3s;
    border: 1px solid var(--medium-gray);
    height: 100%;
    display: flex;
    flex-direction: column;
}

    .course-card:hover {
        transform: translateY(-5px);
        box-shadow: var(--shadow-large);
    }

/* Course Images */
.course-images {
    position: relative;
    height: 220px;
    overflow: hidden;
}

.main-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s;
}

.course-card:hover .main-image {
    transform: scale(1.05);
}

.image-badge {
    position: absolute;
    top: 15px;
    right: 15px;
    background: var(--gradient-primary);
    color: white;
    padding: 6px 15px;
    border-radius: 50px;
    font-size: 12px;
    font-weight: 600;
    box-shadow: 0 4px 12px rgba(0, 102, 204, 0.3);
}

/* Course Content */
.course-content {
    padding: 25px;
    flex-grow: 1;
    display: flex;
    flex-direction: column;
}

.course-title {
    font-size: 22px;
    font-weight: 700;
    color: var(--primary-dark);
    margin-bottom: 12px;
    line-height: 1.3;
}

.course-desc {
    color: var(--text-light);
    font-size: 15px;
    margin-bottom: 20px;
    line-height: 1.5;
    flex-grow: 1;
}

/* Course Features */
.course-features {
    margin: 20px 0;
}

.feature-item {
    display: flex;
    align-items: center;
    margin-bottom: 10px;
    font-size: 14px;
}

    .feature-item i {
        color: var(--accent-green);
        margin-right: 10px;
        font-size: 16px;
        flex-shrink: 0;
    }

/* Pricing */
.course-pricing {
    background: rgba(0, 102, 204, 0.05);
    border-radius: var(--border-radius-small);
    padding: 20px;
    margin: 20px 0;
}

.price-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 10px;
}

.price-label {
    font-size: 14px;
    color: var(--text-light);
    font-weight: 500;
}

.price-amount {
    font-weight: 700;
    font-size: 18px;
    color: var(--primary-dark);
}

.old-price {
    text-decoration: line-through;
    color: var(--text-light);
    font-weight: 500;
}

.new-price {
    color: var(--accent-green);
    font-weight: 700;
}

.currency {
    font-size: 14px;
    color: var(--text-light);
}

/* Buttons */
.btn-course {
    background: var(--gradient-primary);
    border: none;
    color: white;
    padding: 14px 25px;
    border-radius: var(--border-radius-small);
    font-weight: 600;
    font-size: 15px;
    transition: all 0.3s;
    box-shadow: 0 4px 15px rgba(0, 102, 204, 0.25);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    cursor: pointer;
    text-decoration: none;
}

    .btn-course:hover, .btn-course:focus {
        color: white;
        transform: translateY(-2px);
        box-shadow: 0 6px 20px rgba(0, 102, 204, 0.35);
        text-decoration: none;
    }

    .btn-course i {
        margin-right: 8px;
        font-size: 16px;
    }

.btn-outline-course {
    background: transparent;
    border: 2px solid var(--primary-blue);
    color: var(--primary-blue);
    padding: 12px 20px;
    border-radius: var(--border-radius-small);
    font-weight: 600;
    font-size: 14px;
    transition: all 0.3s;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    cursor: pointer;
    text-decoration: none;
    margin-top: 10px;
}

    .btn-outline-course:hover, .btn-outline-course:focus {
        background: rgba(0, 102, 204, 0.05);
        transform: translateY(-2px);
        text-decoration: none;
    }

    .btn-outline-course i {
        margin-right: 6px;
        font-size: 14px;
    }

/* Course Modal */
.course-modal .modal-content {
    border-radius: var(--border-radius);
    border: none;
    box-shadow: var(--shadow-large);
}

.course-modal .modal-header {
    background: var(--gradient-primary);
    color: white;
    border-radius: var(--border-radius) var(--border-radius) 0 0;
    padding: 25px 30px;
    border: none;
}

.course-modal .modal-title {
    font-size: 24px;
    font-weight: 700;
}

.course-modal .modal-body {
    padding: 30px;
}

.course-modal .modal-footer {
    border-top: 1px solid var(--medium-gray);
    padding: 20px 30px;
}

/* Responsive Design */
@media (max-width: 767.98px) {
    .page-header {
        padding: 30px 0 20px;
    }

    .page-title {
        font-size: 32px;
    }

    .page-subtitle {
        font-size: 16px;
        padding: 0 15px;
    }

    .courses-grid {
        padding: 0 10px 40px;
    }

    .course-card {
        margin-bottom: 20px;
    }

    .course-images {
        height: 200px;
    }

    .course-content {
        padding: 20px;
    }

    .course-title {
        font-size: 20px;
    }

    .course-desc {
        font-size: 14px;
    }

    .price-amount {
        font-size: 16px;
    }

    .btn-course, .btn-outline-course {
        padding: 12px 20px;
        font-size: 14px;
    }
}

@media (max-width: 575.98px) {
    .page-title {
        font-size: 28px;
    }

    .page-subtitle {
        font-size: 15px;
    }

    .course-images {
        height: 180px;
    }

    .course-title {
        font-size: 18px;
    }

    .feature-item {
        font-size: 13px;
    }

    .price-amount {
        font-size: 15px;
    }
}

@media (min-width: 768px) {
    .col-sm-6 {
        width: 50%;
    }
}

@media (min-width: 992px) {
    .col-md-4 {
        width: 33.33333333%;
    }
}

@media (min-width: 1200px) {
    .container {
        max-width: 1200px;
    }
}