:root {
  --font-family: 'Open Sans', sans-serif;

  --spacing: 2rem;

  --colour-body: #000;
  --colour-background: #fff;
  --colour-dark-blue: #00f;
}

* {
  padding: 0;
  margin: 0;
  outline: 0;
}

html {
  height: 100%;
  font-size: 62.5%;
}

body {
  background: var(--colour-background);
  color: var(--colour-body);
  font-family: var(--font-family);
  font-size: 1.8rem;
  text-align: center;
}

main {
  margin: 3rem auto;
  max-width: 750px;
}

ul {
  padding: 2rem;
  list-style: none;
}

li {
  display: inline-block;
  margin-right: 3rem;
  margin-bottom: 3rem;
}

hr {
  height: 1px;
  border: 0;
  margin: 3rem 0;
  background: linear-gradient(
    to right,
    #0cf 20%,
    #a068f5 40%,
    #f508fb 60%,
    #fe7000 80%
  );
}

a,
a:visited {
  color: var(--colour-dark-blue);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

img {
  display: inline-block;
  margin-right: 1rem;
  width: 24px;
  height: auto;
  vertical-align: middle;
}

h4 {
  margin-bottom: 1rem;
}