css
/* union-jack-pyjama-symphony.css */
body {
  background-image: linear-gradient(to bottom, #ff69d0, #ff69d0 100%);
  background-size: 100vh 100vw;
  background-position: 0 0;
  background-repeat: no-repeat;
  font-family: 'Bangers', cursive;
  text-shadow: 0 0 10px black;
}

h1 {
  margin: 0;
  padding: 10px 20px 10px 20px;
  border: 4px solid black;
  color: #ff0000;
  text-align: center;
  text-transform: uppercase;
  font-size: 36px;
  background-color: #ff69d0;
  box-shadow: 0 0 10px black;
  border-radius: 10px 10px 10px 10px;
  transition: background-color 0.2s;
  animation: color-change 0.5s;
}

@keyframes color-change {
  to {
    background-color: #ff69d0;
  }
}

h2 {
  margin: 20px;
  padding: 10px 20px 10px 20px;
  border: 4px solid black;
  color: #ff0000;
  text-align: center;
  text-transform: uppercase;
  font-size: 24px;
  background-color: #ff69d0;
  box-shadow: 0 0 10px black;
  border-radius: 10px 10px 10px 10px;
  transition: background-color 0.2s;
  animation: color-change 0.5s;
}

h3 {
  margin: 20px;
  padding: 10px 20px 10px 20px;
  border: 2px solid black;
  color: #ff0000;
  text-align: center;
  text-transform: uppercase;
  font-size: 18px;
  background-color: #ff69d0;
  box-shadow: 0 0 10px black;
  border-radius: 10px 10px 10px 10px;
  transition: background-color 0.2s;
  animation: color-change 0.5s;
}

h1 a {
  color: #ff69d0;
  text-decoration: none;
  text-shadow: 0 0 10px black;
  transition: color 0.2s;
  animation: color-change 0.5s;
}

h2 a {
  color: #ff69d0;
  text-decoration: none;
  text-shadow: 0 0 10px black;
  transition: color 0.2s;
  animation: color-change 0.5s;
}

h3 a {
  color: #ff69d0;
  text-decoration: none;
  text-shadow: 0 0 10px black;
  transition: color 0.2s;
  animation: color-change 0.5s;
}