body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f4f4f4;
}

.slideshow-container {
    width: 85%;
    max-width: 1200px;
    margin: auto;
    overflow: hidden;
    text-align: center;
    position: relative;
    background-color: #fff;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
    padding: 20px;
}

.slideshow-wrapper {
    position: relative;
    max-width: 100%;
}

.slideshow-wrapper::after {
    content: "🔗 Click to verify certificate";
    position: absolute;
    bottom: 10px;
    right: 10px;
    background: rgba(0, 0, 0, 0.7);
    color: white;
    padding: 5px 10px;
    border-radius: 15px;
    font-size: 12px;
    opacity: 0;
    transition: opacity 0.3s ease;
    pointer-events: none;
    z-index: 10;
}

.slideshow-wrapper:hover::after {
    opacity: 1;
}

.slides {
    display: none;
}

.slides img {
    max-width: 100%;
    height: auto;
    cursor: pointer;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.slides img:hover {
    transform: scale(1.02);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

.nav-btn {
    cursor: pointer;
    position: absolute;
    top: 50%;
    width: auto;
    padding: 10px;
    margin-top: -22px;
    color: white;
    font-weight: bold;
    font-size: 18px;
    transition: 0.6s ease;
    border-radius: 0 3px 3px 0;
    user-select: none;
    background-color: rgba(0, 0, 0, 0.5);
}

.next-btn {
    right: 0;
    border-radius: 3px 0 0 3px;
}

.prev-btn {
    left: 0;
}

.slide-counter {
    margin: 20px 0;
    font-size: 18px;
}

/* Course title styles */
.course-title-container {
    margin: 15px 0;
    padding: 0 20px;
}

.course-title {
    font-size: 20px;
    font-weight: 600;
    color: #333;
    margin: 0;
    text-align: center;
    line-height: 1.4;
    padding: 10px 0;
    border-bottom: 2px solid #e0e0e0;
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.thumbnail-container {
    display: flex;
    justify-content: flex-start;
    align-items: center;
    margin-top: 20px;
    overflow-x: auto;
    overflow-y: hidden;
    padding: 10px 0;
    scroll-behavior: smooth;
    white-space: nowrap;
    max-width: 100%;
    min-height: 70px;
}

.thumbnail-container::-webkit-scrollbar {
    height: 8px;
}

.thumbnail-container::-webkit-scrollbar-track {
    background: #f1f1f1;
    border-radius: 4px;
}

.thumbnail-container::-webkit-scrollbar-thumb {
    background: #888;
    border-radius: 4px;
}

.thumbnail-container::-webkit-scrollbar-thumb:hover {
    background: #555;
}

.thumb {
    cursor: pointer;
    height: 50px;
    opacity: 0.6;
    transition: all 0.3s ease;
    margin: 0 5px;
    flex-shrink: 0;
    border-radius: 4px;
}

.thumb:hover, .active {
    opacity: 1;
}

.thumb.current-thumb {
    opacity: 1;
    box-shadow: 0 0 5px #63615f, 0 0 8px #FFA500;
    border: 1px solid #FFD700;
    border-radius: 4px;
    transform: scale(1.1);
    transition: all 0.3s ease;
}

.thumb.current-thumb.specialization {
    box-shadow: 0 0 5px #22375f, 0 0 8px #70b0fa;
    border: 1px solid #4b60db;
}

.modal {
    display: none; 
    position: fixed; 
    z-index: 1; 
    padding-top: 100px; 
    left: 0;
    top: 0;
    width: 100%; 
    height: 100%; 
    overflow: auto; 
    background-color: rgb(0,0,0); 
    background-color: rgba(0,0,0,0.9); 
}

.modal-content {
    max-width: 100%;
    margin: auto;
    display: block;
}

.close {
    position: absolute;
    top: 15px;
    right: 35px;
    color: #f1f1f1;
    font-size: 40px;
    font-weight: bold;
    transition: 0.3s;
    cursor: pointer;
}

.close:hover, .close:focus {
    color: #bbb;
    text-decoration: none;
    cursor: pointer;
}

/* Return button styles */
.return-button-container {
    display: flex;
    justify-content: center;
    align-items: center;
    margin: 30px 0;
    gap: 10px;
}

.return-text {
    font-size: 18px;
    color: #333;
    font-weight: 500;
}

.return-btn {
    background: none;
    border: none;
    cursor: pointer;
    padding: 0;
    transition: transform 0.2s ease, opacity 0.2s ease;
}

.return-btn:hover {
    transform: scale(1.1);
    opacity: 0.8;
}

.return-btn-img {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}