style.css

body {
    padding: 0;
    margin: 0;
    box-sizing: border-box;
}

nav {
    width: 100%;
    height: auto;
    background-color: #333;
    padding: 1em;
    display: flex;
    justify-content: center;
    align-items: center;
    box-shadow: -5px 5px 7px #949393;
    box-sizing: border-box;
    z-index: 100;
}

nav h1 {
    text-transform: uppercase;
    font-size: 5vw;
    color: white;
    margin: 0;
}


.gallery {
    display: flex;
    justify-content: space-around;
    flex-flow: row wrap;
    margin: 20px 0px 0px;
    row-gap: 20px;
}

.gallery .image  {
    width: 32%;
    height: auto;
    padding: 1.5em;
    border-radius: 8px;
    background-color: white;
    box-sizing: border-box;
    box-shadow: 5px 5px 7px #949393;
    overflow: hidden;

}
.gallery .image img {
    transition: transform .5s ease;
    filter: grayscale(0);
    cursor: pointer;
}

.gallery .image img:hover {
    transform: scale(1.17);
    filter: grayscale(100%);
}


/* media queries */

/* tablette */
@media screen and (max-width: 1024px) {

    .gallery {
        display: flex;
        justify-content:center;
        gap: 20px;
    }

    .gallery .image {
        width: 45%;
        padding: 1em;
    } 
}

/*  mobile*/

@media screen and (max-width:480px) {
    .gallery{
        display: flex;
        flex-direction: column;
        margin: 20px;
    }

    .gallery .image{
        padding: 1em;
        width: 100%;
    }
}