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

body {
    background: linear-gradient(45deg, rgb(65, 33, 207), rgb(13, 192, 247));
    color: #fff;
    min-height: 100vh;
    min-width: 100vw;
    display: flex;
    flex-direction: column;
    justify-content: center;
    font-family: Arial, Helvetica, sans-serif;
    padding: 64px;
    overflow-x: hidden;
}

h1 {
    margin: 96px;
    font-size: 96px;
    text-align-last: center;
    color: #fff;
}

.gallery {
    border-radius: 25px;
    background: linear-gradient(60deg, rgba(255,255,255,0.1), rgba(255,255,255,0.5));
    display: flex;
    flex-wrap: wrap;
    justify-content: space-evenly;
    list-style-type: none;
    padding: 64px;
}

.thumbnail {
    border: solid 3px, rgba(255,255,255,0.9);
    box-shadow: 0 0 48px 1px rgba(0,0,0,0.5);
    border-radius: 15px;
    overflow: hidden;
    cursor: pointer;
    margin: 32px;
    max-height: 200px;
    max-width:  300px;
    transform: scale(1);
    transition: transform 0.3s;
}

.thumbnail img {
    height: 100%;
    width: 100%;
    object-fit: cover;
    /*
    border: solid 3px, rgba(0,0,0,0.9);
    border-radius: 15px;
    */
} 

.thumbnail img:focus-visible,
.thumbnail img:focus {
    border: solid 5px rgb(65, 33, 207);
}

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

.popup {
    align-content: center;
    animation: fadeIn 0.35s;
    background: rgba(0,0,0,0.5);
    backdrop-filter: blur(10px);
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    height: 100vh;
    left: 0;
    position: fixed;
    top: 0;
    width: 100vw;
    
}

.popup.hidden {
    display: none;
}

.popup.fade-out {
    animation: fadeOut 0.3s both;
}

.popup__img {
    border: solid 5px #000;
    border-radius: 25px;
    max-height: 90%;
    max-width: 90%;
    object-fit: contain;
    display: block;
}

.popup__close {
    position: fixed;
    top: 10%;
    right: 5%;
}

.popup__arrow {
    position: absolute;
    top: 50%;
}  

.popup__close,
.popup__arrow {
    border: none;
    border-radius: 50%;
    background-color: rgba(255,255,255,0.5);
    cursor: pointer;
    font-size: 48px;
    height: 48x;
    line-height: 48px;
    opacity: 50%;
    width: 48px;
}

.popup__close:hover,
.popup__arrow:hover {
    transition: opacity 0.3s;
    opacity: 100%;
}

.popup__arrow--left {
    left: 5%;
}

.popup__arrow--right {
    right: 5%; 
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
    
}

@keyframes fadeOut {
    from {
        opacity: 1;
    }
    to {
        opacity: 0;
    }
    
}