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

header {
    background-color: #4287f5;
    color: white;
    padding: 1rem;
    text-align: center;
}

 header h1 {
    margin-bottom: 1rem;
 }

 header a {
    color: white;
    text-decoration: none;
}

.menu-btn {
    background: none;
    border: none;
    color: white;
    cursor: pointer;
    padding: 0.5rem;
}

.menu-btn h4 {
    margin-bottom: 0.5rem;
}

.bar1, .bar2, .bar3 {
    width: 25px;
    height: 3px;
    background-color: white;
    margin: 4px 0;
    transition: 0.4s;
}

.menu-btn.open .bar1 {
    transform: rotate(-45deg) translate(-5px, 6px);
}

.menu-btn.open .bar2 {
    opacity: 0;
}

.menu-btn.open .bar3 {
    transform: rotate(45deg) translate(-5px, -6px);
}

header nav ul {
    list-style: none;
    display: none;
    margin: 0 auto;
    max-width: 300px;
}

header nav ul.show {
    display: block;
}

header nav ul li {
    padding: 0.75rem 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.2);
}

header nav ul li a {
    display: block;
    padding: 0.5rem;
}

header nav ul li a:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

footer {
    background-color: #4287f5;
    padding: 1rem;
    text-align: center;
}

img {
    box-shadow: 4px 4px 8px rgba(0, 0, 0, 0.5);
    border: solid black 2px;
    margin: 15px;
    max-width: 100%;
    height: auto;
}
dialog img {
    max-width: 80vw;
    max-height: 80vh;
    width: auto;
    height: auto;
    object-fit: contain;
}
dialog {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    margin: 0;
    padding: 1rem;
    border: 2px solid black;
    background-color: rgba(0, 0, 0, 0.9);
}
main {
    display: flex;
    flex-direction: column;
    padding: 2rem;
    background-color: lightgrey;
}

main h2 {
    margin-bottom: 1rem;
    text-align: center;
}

main div {
    display: flex;
    flex-direction: column;
}

@media screen and (min-width: 768px) {
    main div {
        flex-direction: row;
        flex-wrap: wrap;
    }
}

@media screen and (min-width: 1200px) {
    main div {
        flex: 1 1 30%;
    }

    main {
        flex-wrap: nowrap;
    }

    header nav ul {
        display: flex !important;
        flex-direction: row;
        gap: 2rem;
    }

    header nav ul li {
        padding: 0;
        border-bottom: none;
    }

    .menu-btn {
        display: none;
    }
}