* {
  box-sizing: border-box;
}

html,
body {
  height: 100%;
  margin: 0;
  padding: 0;
}

body {
  font-family: Arial, sans-serif;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  background-color: #f4f4f4;
  color: #333;
  line-height: 1.6;
}

header {
  background-color: #222;
  color: white;
  padding: 1rem;
  text-align: center;
}

header h1 {
  margin: 0.2rem 0;
}

nav ul {
  list-style: none;
  padding: 0;
  display: flex;
  justify-content: center;
  gap: 20px;
  margin: 0;
}

nav a {
  color: white;
  text-decoration: none;
}

nav a.active {
  font-weight: bold;
  color: yellow;
}

main {
  flex: 1;
  max-width: 800px;
  margin: 20px auto;
  padding: 0 1rem;
}

img {
  flex: auto;
  align-items: center;
  max-width: 90%;
}

footer {
  background-color: #222;
  color: white;
  text-align: center;
  padding: 10px;
  margin-top: auto;
}