style.css

:root {
    --color-default: #111;
    --color-links: #555;

    --color-github: #000;
    --color-linkedin: #0072b1;
    --color-resume: #a00;
    --color-stackoverflow: #f48024;
}

body {
    margin: 0;
    font-family: 'Open Sans';
    font-weight: 400;
    color: var(--color-default);
}

main, nav, ul, li, a {
    display: flex;
    flex-direction: column;
    justify-content: center;
}

main {
    min-height: 100vh;
    align-items: stretch;
    font-size: 6vw;
    text-align: center;
}

@media (min-width: 25rem) {
    main {
        font-size: 1.5rem;
    }
}

h1 {
    font-size: 1.75em;
    font-weight: 300;
    margin: 0 0 1em;
}

nav {
    align-items: center;
}

ul {
    align-items: stretch;
    list-style-type: none;
    margin: 0;
    padding: 0;
}

li {
    align-items: center;
    margin: 0.5em 0 0;
}
li:first-child {
    margin-top: 0;
}

a {
    align-items: center;
    position: relative;
    color: var(--color-links);
    text-decoration: none;
    padding: 0.5em 0.25em;
    transition: color 0.3s ease-in-out;
}
a:after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 0.15em;
    opacity: 0;
    background-color: currentColor;
    transition: opacity 0.3s ease-in-out, width 0.3s ease-in-out;
}
a:focus {
    outline: none;
}
a:focus:not(:active):after,
a:hover:after {
    width: 100%;
    opacity: 1;
}

a[href^="files/resume"]:focus:not(:active),
a[href^="files/resume"]:hover {
    color: var(--color-resume);
}
a[href^="https://linkedin.com"]:focus:not(:active),
a[href^="https://linkedin.com"]:hover,
a[href^="https://www.linkedin.com"]:focus:not(:active),
a[href^="https://www.linkedin.com"]:hover {
    color: var(--color-linkedin);
}
a[href^="https://stackoverflow.com"]:focus:not(:active),
a[href^="https://stackoverflow.com"]:hover,
a[href^="https://www.stackoverflow.com"]:focus:not(:active),
a[href^="https://www.stackoverflow.com"]:hover {
    color: var(--color-stackoverflow);
}
a[href^="https://github.com"]:focus:not(:active),
a[href^="https://github.com"]:hover,
a[href^="https://www.github.com"]:focus:not(:active),
a[href^="https://www.github.com"]:hover {
    color: var(--color-github);
}