@keyframes loading1 {
  0% {
    opacity: 0;
  }
  100% {
    opacity: 1;
  }
}

@keyframes loading2 {
  0% {
    transform: scale(0,1);
  }
  100% {
    transform: scale(1,1);
  }
}

html {
  height: 98%;
  background: url('../imgs/background.png');
  background-position: center;
  background-size: 280vh;
  font-family: sans-serif;
  -moz-user-select: none;
  -webkit-user-select: none;
  -ms-user-select: none;
  margin: 0 100px;
}

body {
  height: 100%;
  display: grid;
  grid-template-rows: 50px 1fr 1fr 1fr 50px;
  place-items: center;
  animation: loading1 0.4s;
}

h1 {
  display: flex;
  font-size: 5vw;
  margin: 0;
  align-items: center;
  justify-content: center;
  position: relative;
}

h1:before {
  bottom: 0;
  width: 100%;
  content: '';
  position: absolute;
  animation: loading2 1s;
  border-bottom: solid 2px green;
}

.btn {
  display: flex;
  font-size: 3vw;
  margin: 0;
  padding: 0;
  height: 45%;
  width: 40%;
  align-items: center;
  justify-content: center;
  text-align: center;
  background-color: #9ec34b;
  border-radius: 40px;
  color: white;
  transition: 0.1s;
  cursor: pointer;
}

.btn:hover {
  height: 47%;
  width: 42%;
  background-color: #aed35b;
}