body {
  background-color: color-mix(in srgb, white 90%, black);
  font-family: Arial;
}
div {
  position: fixed;
  top: 50%;
  left: 50%;
  width: 100%;
  max-width: 500px;
  height: auto;
  padding: 20px 40px;
  border: 1px solid color-mix(in srgb, white 70%, black);
  background: #fff;
  transform: translateX(-50%) translateY(-50%);
  box-sizing: border-box;
  color: color-mix(in srgb, white 30%, black);
}
ul {
  list-style: none;
  margin: 0;
  padding: 0;
}
li {
  display: inline-block;
}
a {
  display: inline-block;
  background: blue;
  border-radius: 5px;
  padding: 5px 10px;
  color: #fff;
  text-decoration: none;
}
a:hover {
  background: color-mix(in srgb, blue 80%, black);
}