style.css

html,
body {
  margin: 0;
  font-family: "PingFang SC", "Microsoft Yahei", sans-serif;
}

* {
  box-sizing: border-box;
}

ul,
li {
  padding: 0;
  margin: 0;
}

li {
  list-style: none;
}

main {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  min-height: 100vh;
  width: 100vw;
  background: #c0c0aa; /* fallback for old browsers */
  background: -webkit-linear-gradient(
    to right,
    #1cefff,
    #c0c0aa
  ); /* Chrome 10-25, Safari 5.1-6 */
  background: linear-gradient(
    to right,
    #1cefff,
    #c0c0aa
  ); /* W3C, IE 10+/ Edge, Firefox 16+, Chrome 26+, Opera 12+, Safari 7+ */
}

.card {
  border-radius: 12px;
  min-width: 450px;
  margin: 40px;
  padding: 40px;
  box-shadow: 0 0 24px rgba(0, 0, 0, 0.2);
  background: rgba(255, 255, 255, 0.3);
}

ul li {
  margin: 18px 0;
}

li a {
  display: block;
  color: white;
  text-shadow: 0 0 2px rgba(180, 124, 117, 0.4);
  text-decoration: none;
  text-align: center;
  font-size: 18px;
  padding: 18px;
  border-radius: 12px;
  background: #ffafbd; /* fallback for old browsers */
  background: -webkit-linear-gradient(
    to right,
    #ffc3a0,
    #ffafbd
  ); /* Chrome 10-25, Safari 5.1-6 */
  background: linear-gradient(
    to right,
    #ffc3a0,
    #ffafbd
  ); /* W3C, IE 10+/ Edge, Firefox 16+, Chrome 26+, Opera 12+, Safari 7+ */
}

@media screen and (max-width: 512px) {
  .card {
    min-width: 350px;
    padding: 4rem;
  }
  li a {
    padding: 1rem;
  }
}