gellery.css

/* styles.css */

body {
    font-family: Arial, sans-serif;
    background: #b6b9bb;
    background-image: url('images/s.jpg');
    /*background-size: cover;*/
    background-blend-mode: lighten;
    background-color: rgba(255, 255, 255, 0.8);
}

.gallery {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    padding: 20px;
    margin-right: 10px;
}

.gallery-item {
    margin: 5px;
}

.thumbnail {
    width: 150px;
    height: auto;
    cursor: pointer;
    transition: 0.3s;
}

.thumbnail:hover {
    transform: scale(1.1);
}


/* The Modal (background) */

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


/* Modal Content */

.modal-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.modal-content .mySlides {
    display: flex;
}

.modal-content img {
    max-width: 90%;
    max-height: 80vh;
}


/* Next & previous buttons */

.prev,
.next {
    cursor: pointer;
    position: absolute;
    top: 50%;
    width: auto;
    padding: 16px;
    margin-top: -50px;
    color: white;
    font-weight: bold;
    font-size: 20px;
    transition: 0.6s ease;
    border-radius: 0 3px 3px 0;
    user-select: none;
}

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

.prev:hover,
.next:hover {
    background-color: rgba(54, 45, 45, 0.8);
}


/* Caption text */

.caption-container {
    text-align: center;
    background-color: black;
    padding: 2px 16px;
    color: white;
}


/* Number text (1/3 etc) */

.numbertext {
    color: #f2f2f2;
    font-size: 12px;
    padding: 8px 12px;
    position: absolute;
    top: 0;
}


/* Close button */

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

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