h1 {
  text-align: center;
  }

body {
  background-image: radial-gradient(circle, white, red);
  height: 100vh;
}

#ahoj-button {
  transition-duration: 0.5s;
  cursor: pointer;
  background-color: white; 
  color: black; 
  border: 3px solid blue;
}

#ahoj-button:hover {
  background-color: blue; 
  color: white;
}

.button {
  transition-duration: 0.5s;
  cursor: pointer;
}

.button1 {
  background-color: white; 
  color: black; 
  border: 3px solid green;
}

.button1:hover {
  background-color: green;
  color: white;
}

.button2 {
  background-color: white; 
  color: black; 
  border: 3px solid blue;
}

.button2:hover {
  background-color: blue;
  color: white;
}