style.css

body {
  background-color: #1d2d5f;
}

#particles-js {
  position: fixed;
  width: 100%;
}

#colContain {
    position: relative;
    background: url('img/surprise.png') top no-repeat;
    background-size: cover;
    display: block;
    margin: 0 auto;
    padding-left: 0;
    padding-right: 0;
}

.square {
    z-index: 1;
    display: inline-block;
    top: 0;
    width: 10%;
}

.square a {
    display: block;
    background-color: #1D2D5F;
    color: #FFFFFF;
    text-decoration: none;
    transition: all .3s;
    padding: 11% 0;
}

.square a:hover {
    background: linear-gradient(60deg, #f79533, #f37055, #ef4e7b, #a166ab, #5073b8, #1098ad, #07b39b, #6fba82);
    color: #1A2555;
    border: inherit;
}

a.cliked:hover {
    background: none !important;
    color: rgba(0,0,0,0) !important;
    border: inherit !important;
}

.rowed {
  display: block;
  margin: 0 auto;
  text-align: center;
  top: 0;
  left: 0px;
  width: 100%;
}

#yike {
  position: fixed;
  bottom: 10px;
  right: 10px;
  padding: 10px;
  cursor: pointer;
}

.gradient-border {
  --borderWidth: 1.5px;
  position: relative;
  border-radius: var(--borderWidth);
}

.gradient-border:after {
  content: '';
  position: absolute;
  top: calc(-1 * var(--borderWidth));
  left: calc(-1 * var(--borderWidth));
  height: calc(100% + var(--borderWidth) * 2);
  width: calc(100% + var(--borderWidth) * 2);
  background: linear-gradient(60deg, #f79533, #f37055, #ef4e7b, #a166ab, #5073b8, #1098ad, #07b39b, #6fba82);
  border-radius: calc(2 * var(--borderWidth));
  z-index: -1;
  animation: animatedgradient 3s ease alternate infinite;
  background-size: 300% 300%;
}

.clicked::after {
  display: none;
  visibility: hidden;
}


@keyframes animatedgradient {
	0% {
		background-position: 0% 50%;
	}
	50% {
		background-position: 100% 50%;
	}
	100% {
		background-position: 0% 50%;
	}
}