a {
  text-decoration: none;
  position: relative;
  overflow: hidden;
  z-index: 0;
}

a::after {
  content: "";
  position: absolute;
  top: -50%;
  right: -50%;
  bottom: -50%;
  left: -50%;
  background: linear-gradient(45deg, #ff0000, #00ff00, #0000ff, #ff0000, #00ff00, #0000ff);
  background-size: 300% 300%;
  z-index: -1;
  border-radius: 100vmax;
  filter: blur(10px);
  opacity: 0;
  transition: opacity 0.3s ease-in-out;
  animation: rotate-97 5s linear infinite;
}

a:hover::after {
  opacity: 1;
}

@keyframes rotate-97 {
  0% {
    transform: rotate(0deg);
  }
  100% {
    transform: rotate(360deg);
  }
}
body {
    margin: 0;
    font-family: Arial, sans-serif;
    background-image: url("../img/istockphoto-1866027488-612x612.jpg");
    background-repeat: no-repeat;
    background-attachment: fixed;
  background-position: center;
  background-size: cover;
    height: 300vh;
}
.logo {
    font-style: initial;
    font-size:32px;
      text-shadow: #93e193 20px 10px 8px;
    color: #f5f4f4;;
    text-decoration: none;
    font-weight: 700;
}

header {
  position: relative;
}

.navbar {
    position: sticky;
    top: 20px;
    font-size: larger;
  padding: 4px 250px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}
.navbar a {
  text-shadow: #93e193 10px 1px 8px;
    color: rgb(234, 234, 234);
    font-weight: bold;
}