style.css

html,
body {
  height: 100%;
  width: 100%;

}

.background {
  height: 100%;
  width: 100%;
  background-image: linear-gradient(to left, violet, indigo, blue, green, yellow, orange, red);
  animation-name: back;
  animation-duration: 5s;
  animation-iteration-count: infinite;
}



.top {
  background-color: rgba(216, 232, 232, 0.5);
  width: auto;
  height: auto;
  margin-right: 20%;
  margin-left: 20%;
  border: rgb(252, 177, 3);
  border-style: groove;
  justify-content: center;
  text-align: center;

  position: absolute;
  top: 50%;
  width: 50%;
  text-align: center;
  font-size: 18px;

}

.h1 {
  font-family: 'Dancing Script', cursive;
  font-family: 'Montserrat', sans-serif;
  font-family: 'Noto Sans', sans-serif;

}


.div {
  height: 100%;
  width: 100%;
  border: 1px;
  border-color: black;
  border-style: solid;
}

.button {

  background-color: #4CAF50;
  /* Green */
  border: none;
  color: white;
  padding: 16px 32px;
  text-align: center;
  text-decoration: none;
  display: inline-block;
  font-size: 16px;
  margin: 4px 2px;
  transition-duration: 0.4s;
  cursor: pointer;
}

.button1 {
  background-color: white;
  color: black;
  border: 2px solid #4CAF50;
}

.button1:hover {
  background-color: #4CAF50;
  color: white;
}

.button2 {
  background-color: white;
  color: black;
  border: 2px solid #008CBA;
}

.button2:hover {
  background-color: #008CBA;
  color: white;
}

.button3 {
  background-color: white;
  color: black;
  border: 2px solid #f44336;
}

.button3:hover {
  background-color: #f44336;
  color: white;
}

@keyframes back {
  0% {
    opacity: 0.2;
  }

  50% {
    opacity: 1;
  }

  100% {
    opacity: 0.2;
  }
}

                                              /* By- Vibhor Jaiswal */