style.css

:root {
  --logo-width: 300px;
  --spin-speed: 1.3s;
}

* {
  padding: 0;
  margin: 0;
  box-sizing: border-box;
}

body {
  height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 10px 0;
  font-family: 'Montserrat', sans-serif;
  font-size: 20px;
  color: #27ae60;
  background-color: #ecf0f1;
  cursor: default;
}

.preloader {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  z-index: 100;
  background-color: #090c31;
  display: flex;
  justify-content: center;
  align-items: center;
  transition: opacity .25s ease;
}

.preloader--invisible {
  opacity: 0;
}

.preloader--hidden {
  visibility: hidden;
}

.preloader__logo {
  width: var(--logo-width);
  padding-bottom: 10px;
  background: url('logo.svg') no-repeat center;
  background-size: 40%;
}

.preloader__circle {
  border-top: 2px solid #fff;
  border-radius: 50%;
  width: calc(var(--logo-width) + 10px);
  height: calc(var(--logo-width) + 10px);
  animation: preloader-spin var(--spin-speed) linear infinite;
}

@keyframes preloader-spin {
  0% {
    transform: rotate(0deg);
  }

  100% {
    transform: rotate(360deg);
  }
}