@import url('https://fonts.googleapis.com/css2?family=REM&display=swap');
body {
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100vh;
    background: #111;
    background-image: linear-gradient(rgba(0, 0, 0, .8) .25em, transparent .1em), linear-gradient(90deg, rgba(0, 0, 0, .8) .25em, transparent .1em);
    background-size: 7em 7em;
    animation: slide 20s linear infinite;
    font-family: 'REM';
}
@keyframes slide {
    from {
        background-position: center top;
    }
    to {
        background-position: center bottom;
    }
}
div {
    position: absolute;
    top: 50%;
    left: 50%;
    color: white;
    transform: translate(-50%, -50%);
    text-align: center;
}
h1 {
    font-size: 5rem;
    line-height: 0.5;
}
p {
    font-size: 2rem;
    line-height: 1.2;
    margin-bottom: 15px;
}
button {
    background-color: #222;
    border: none;
    color: white;
    padding: 20px;
    font-size: 20px;
    margin: 5px 5px;
    border-radius: 15px;
    margin-top: 15px;
}
button:hover {background-color: #333;}