:root {
  font-family: system-ui, sans-serif;
  color-scheme: light dark;
}
body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  place-items: center;
}
main {
  width: min(640px, calc(100% - 48px));
}
.mark {
  width: 72px;
  height: 72px;
}
nav {
  display: flex;
  gap: 18px;
  margin-top: 28px;
}
a {
  color: inherit;
}