* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: "Helvetica Neue", Arial, sans-serif;
  line-height: 1.6;
  background: #f4f4f9;
  color: #333;
  padding: 20px;
  max-width: 768px;
  margin-left: auto;
  margin-right: auto;
}

h1,
h2 {
  margin-bottom: 20px;
  color: #222;
}

h1 {
  font-size: 2.5em;
  text-align: center;
  margin-top: 20px;
}

h2 {
  font-size: 1.8em;
  border-bottom: 2px solid #ccc;
  padding-bottom: 10px;
  margin-top: 40px;
}

ul {
  list-style-type: none;
  margin-top: 20px;
}

ul li {
  background: #fff;
  margin-bottom: 10px;
  border-radius: 5px;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
  transition: background 0.3s;
}

ul li:hover {
  background: #e9e9f0;
}

a {
  text-decoration: none;
  padding: 15px;
  color: #3498db;
  font-weight: bold;
  display: block;
}

a:hover {
  color: #2980b9;
}

.unsupported-text {
  font-weight: bold;
  text-align: center;
  margin-top: 20px;
}