body {
    background: url(../images/background.jpeg);
}

.navbar {
    float: right;
}

.menu {
    position: fixed;
    z-index: 999;
    top: 0;
    left: auto;
    width: 100%;
}

.menu.start {
    width: 68%;
    left: 50%;
    right: 50%;
    transform: translate(-50%);
}

.gallery {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    grid-gap: 30px;
}

.gallery img {
    width: 100%;
}