style.css

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  height: 100vh;
  width: 100vw;
}

body > main > img {
  height: 100%;
  width: 100%;
  position: absolute;
  inset: 0;
  object-position: center bottom;
  object-fit: cover;
}

h1 {
  z-index: -1;
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  font-size: 140px;
  margin: 0;
}

body > #loader {
  background-color: #fff;
  position: absolute;
  inset: 0;
  z-index: 99;
  animation: 0.3s linear 2s forwards fadeout;
}

body > #loader > .wrapper {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}

body > #loader > .wrapper > .dots {
  margin: 0 auto;
  display: flex;
  flex-flow: row nowrap;
  column-gap: 10px;
  justify-content: center;
}

body > #loader > .wrapper > .dots > .dot {
  height: 15px;
  width: 15px;
  border-radius: 50%;
  background-color: #000;
  animation: 1s linear infinite jump;
  position: relative;
  top: 0;
}

body > #loader > .wrapper > .dots > .dot:nth-of-type(1) {
  animation-delay: 0s;
}

body > #loader > .wrapper > .dots > .dot:nth-of-type(2) {
  animation-delay: 0.3s;
}

body > #loader > .wrapper > .dots > .dot:nth-of-type(3) {
  animation-delay: 0.6s;
}

body > #loader > .wrapper > .text {
  margin-top: 10px;
  font-size: 30px;
  font-family: 'Raleway', sans-serif;
}

.device-recommendation {
  display: none;
  margin: auto;
  position: relative;
  top: 50vh;
  transform: translateY(-50%);
  width: 100%;
  max-width: 400px;
  padding: 10px;
  font-family: 'Raleway', sans-serif;
}

@media screen and (max-width: 768px) {
  .device-recommendation {
    display: block;
  }

  main {
    display: none;
  }
}

@keyframes fadeout {
  0% {
    opacity: 1;
    display: block;
    visibility: visible;
  }

  99% {
    opacity: 0;
    display: block;
    visibility: visible;
  }

  100% {
    opacity: 0;
    display: none;
    visibility: hidden;
    pointer-events: none;
  }
}

@keyframes jump {
  0% {
    top: 0;
  }

  33% {
    top: -10px;
  }

  66% {
    top: 0;
  }

  100% {
    top: 0;
  }
}