:root {
  --hue: 200;
  --sat: 50%;
  --lum: 50%;
}

html {
  box-sizing: border-box;
  scroll-behavior: smooth;
  height: 100%;
}

body {
  font-family: "Roboto", "Helvetica", "Arial", sans-serif;
  font-size: 1.6rem;
  line-height: 1.5;
  color: #212121;
  background-color: #fafafa;
  margin: 0;
  min-height: 100%;
}

* {
  box-sizing: inherit;
  margin: 0;
  padding: 0;
  color: inherit;
  text-decoration: none;
}

#app {
  min-height: 100%;
}
#app > header, #app > footer {
  background-color: hsl(var(--hue), var(--sat), var(--lum));
  color: #fff;
}
#app > nav {
  background-color: hsl(var(--hue), var(--sat), 40%);
  color: #fff;
}
#app > nav ul {
  justify-content: center;
  display: flex;
  list-style-type: none;
  gap: 1rem;
}
#app > nav a {
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 1rem;
}
#app > nav a:hover {
  background-color: hsl(var(--hue), var(--sat), 50%);
}