body {
    margin: 0;
    padding: 0;
}

header, main, footer {
    padding: 1rem;
}

header, footer {
    background-color: lightskyblue;
    text-align: center;
    color: white;
}

.menu-btn {
    cursor: pointer;
    border: none;
    background-color: transparent;
    color: white;
    font-size: 1.2em;
}

nav a {
    padding: 20px;
    color: white;
    display: block;
}

.hidden {
    display: none;
}

a:hover {
    text-decoration: none;
}

main {
    background-color: lightgray;
    text-align: center;
    
}

#images {
    display: grid;
    grid-template-columns: 1fr;
    gap: 20px;
}

img {
    object-fit: cover;
    aspect-ratio: 1;
    width: 60%;
    margin: auto;
    border: solid white 3px;
    box-shadow: 5px 5px 10px;
}

dialog img {
    width: 60%;
    display: block;
    margin: 20vh auto;
}

dialog {
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.75);
}

.close-viewer {
    position: absolute;
    top: 20vh;
    right: 5vh;
    padding: 3px 6px;
}

@media screen and (min-width: 700px) {
    #images {
        grid-template-columns: 1fr 1fr;
    }
}

@media screen and (min-width: 1000px) {

    .menu-btn {
        display: none;
    }

    nav a {
        display: inline;
    }

    #images {
        grid-template-columns: repeat(3, 1fr);
        margin: auto;
        max-width: 900px;
    }

    .hidden {
        display: inline;
    }
    
}