body {
  font-family: Roboto;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
}
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}