body {
  font-family: Arial, sans-serif;
  margin: 0;
  background: #f4f6f8;
}

header {
  background: #1e88e5;
  color: white;
  text-align: center;
  padding: 30px;
}

nav {
  background: #333;
  text-align: center;
  padding: 10px;
}

nav a {
  color: white;
  margin: 10px;
  text-decoration: none;
}

.tools {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  padding: 20px;
}

.tool {
  background: white;
  width: 250px;
  margin: 10px;
  padding: 20px;
  border-radius: 8px;
  box-shadow: 0 0 10px rgba(0,0,0,0.1);
}

footer {
  background: #222;
  color: white;
  text-align: center;
  padding: 15px;
}