:root {
    --animation-duration: 500ms;
}

body,
html {
    height: 100%;
}

body {
    font-family: Arial, Helvetica, sans-serif;
    color: #333;
}

.container {
    max-width: 768px;
    margin: 0 auto;
}

h1 {
    font-size: 2.8rem;
    font-weight: bold;
}

p {
    margin-top: 20px;
}

p:nth-last-child(1) {
    margin-bottom: 20px;
}

aside {
    width: 100%;
    position: fixed;
    bottom: 0;
    background-color: #000000dd;
    color: white;
    padding: 10px;
}

span {
    margin: -0.13rem;
    padding: 0;
    animation: rainbow var(--animation-duration) linear infinite;
}

span:nth-of-type(1),
span:nth-of-type(8),
span:nth-of-type(15) {
    animation-delay: 0;
}

span:nth-of-type(2),
span:nth-of-type(9),
span:nth-of-type(16) {
    animation-delay: calc(var(--animation-duration) / 7);
}

span:nth-of-type(3),
span:nth-of-type(10) {
    animation-delay: calc(var(--animation-duration) / 7 * 2);
}

span:nth-of-type(4),
span:nth-of-type(11) {
    animation-delay: calc(var(--animation-duration) / 7 * 3);
}

span:nth-of-type(5),
span:nth-of-type(12) {
    animation-delay: calc(var(--animation-duration) / 7 * 4);
}

span:nth-of-type(6),
span:nth-of-type(13) {
    animation-delay: calc(var(--animation-duration) / 7 * 5);
}

span:nth-of-type(7),
span:nth-of-type(14) {
    animation-delay: calc(var(--animation-duration) / 7 * 2);
}

.space {
    margin: 0 5px;
}

@keyframes rainbow {
    0%,
    100% {
        color: red;
    }

    14% {
        color: orange;
    }

    28% {
        color: yellow;
    }

    42% {
        color: lightgreen;
    }

    56% {
        color: cyan;
    }

    70% {
        color: blue;
    }

    84% {
        color: purple;
    }
}

@media (max-width: 768px) {
    .container {
        padding: 30px;
    }
}