.slider-instance {
    width: 600px;
    max-width: 100%;
}
.slider-instance .slider-container {
    position: relative;
    max-width: 800px;
    width: 100%;
    margin: auto;
    border: 1px solid #ddd;
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
}
.slider-instance .main-image-container {
    width: 100%;
    aspect-ratio: 4 / 4; 
    overflow: hidden;
    position: relative;
    border: 1px solid #ebebeb;
}
.slider-instance .main-image-container img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    position: absolute;
    top: 0;
    left: 0;
    opacity: 0;
    transition: opacity 0.5s ease-in-out;
}
.slider-instance .main-image-container img.active {
    opacity: 1;
}
.slider-instance .prev-btn, .slider-instance .next-btn {
    cursor: pointer;
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    width: auto;
    padding: 16px;
    color: white;
    font-weight: bold;
    font-size: 20px;
    background-color: rgba(0, 0, 0, 0.4);
    border-radius: 0 3px 3px 0;
    user-select: none;
    transition: background-color 0.3s ease;
    z-index: 1;
}
.slider-instance .next-btn {
    right: 0;
    border-radius: 3px 0 0 3px;
}
.slider-instance .prev-btn:hover, .slider-instance .next-btn:hover {
    background-color: rgba(0, 0, 0, 0.8);
}
.slider-instance .slide-counter {
    position: absolute;
    top: 10px;
    left: 10px;
    color: white;
    background-color: rgba(0, 0, 0, 0.6);
    padding: 5px 10px;
    border-radius: 5px;
    font-size: 14px;
    z-index: 1;
}
.slider-instance .thumbnail-wrapper {
    display: flex;
    align-items: center;
    justify-content: center;
    max-width: 800px;
    width: 100%;
    margin-top: 15px;
    padding: 0 40px; /* Tạo không gian cho nút */
    position: relative;
}
.slider-instance .thumbnail-scroller {
    width: 100%;
    overflow: hidden;
}
.slider-instance .thumbnail-track {
    display: flex;
    gap: 10px;
    transition: transform 0.5s ease-in-out;
    padding: 5px 0;
}
.slider-instance .thumbnail-track img {
    width: 100px;
    height: auto;
    object-fit: contain;
    cursor: pointer;
    border: 3px solid #ccc;
    transition: border-color 0.3s ease, transform 0.3s ease, opacity 0.3s ease;
    opacity: 0.7;
    flex-shrink: 0;
}
.slider-instance .thumbnail-track img:hover {
    opacity: 1;
    transform: scale(1.05);
}
.slider-instance .thumbnail-track img.active-thumb {
    border-color: #e53935;
    opacity: 1;
}
.slider-instance .thumb-prev-btn, .slider-instance .thumb-next-btn {
    cursor: pointer;
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background-color: #ddd;
    border-radius: 50%;
    width: 30px;
    height: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    font-size: 18px;
    user-select: none;
    transition: background-color 0.3s ease;
    z-index: 1;
}
.slider-instance .thumb-prev-btn {
    left: 0;
}
.slider-instance .thumb-next-btn {
    right: 0;
}
.slider-instance .thumb-prev-btn:hover, .slider-instance .thumb-next-btn:hover {
    background-color: #bbb;
}
.slider-instance .thumb-prev-btn.disabled, .slider-instance .thumb-next-btn.disabled {
    opacity: 0.4;
    cursor: not-allowed;
}