:root {
  --primary:    #4caf50;
  --background: #f0f0f0;
  --surface:    #ffffff;
  --text:       #333333;
}

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

body {
  font-family: Arial, sans-serif;
  line-height: 1.6;
  color: var(--text);
  background-color: var(--background);
}

header,
footer {
  background-color: var(--primary);
  color: white;
  text-align: center;
  padding: 1em;
}

main {
  max-width: 800px;
  margin: 2em auto;
  padding: 1em;
  background-color: var(--surface);
}

ul {
  list-style-type: none;
}

li {
  padding: 0.5em 0;
}

a {
  color: var(--primary);
  text-decoration: none;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin: 1em 0;
}

th,
td {
  border: 1px solid #ddd;
  padding: 0.5em;
  text-align: left;
}

th {
  background-color: var(--primary);
  color: white;
}

@media (max-width: 600px) {
  header,
  footer {
    padding: 0.5em;
  }

  main {
    margin: 1em;
    padding: 0.5em;
  }

  table,
  th,
  td {
    font-size: 0.9em;
  }
}