style.css

@import url('https://fonts.googleapis.com/css2?family=Cairo+Play&family=Happy+Monkey&family=Oswald&display=swap');
html {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  
  display: flex;
  justify-content: center;
  align-items: center;
  background: darkgrey;
}

.button-container{
  border: 2px solid black;
  border-radius: 10px;
  padding: 10px;
  box-shadow: inset 0 20px 4px -20px salmon;
  background: slateblue;
}

button{
  cursor: pointer;
  font-family: 'Happy Monkey', cursive;
  outline: none;
  width: 120px;
  height: 75px;
  font-size: 25px;
  color: rgb(31, 31, 31);
  text-shadow: 0 2px 5px black;
  background-color: linear-gradient(0deg, rgba(255,255,255,1) 0%, rgba(255,255,255,1) 50%, rgba(255,255,255,0) 100%);
  border: 2px solid black;
  border-radius: 10px;
  box-shadow: inset 0 20px 4px -20px salmon, 0 12px 11px 0 rgba(red, green, blue, 0.4);
}

button:hover{
  background: linear-gradient(to bottom, rgba(255,255,255,1) 0%, rgba(255,255,255,1) 50%, rgba(255,255,255,0) 100%);
  box-shadow: inset 0 20px 4px -20px salmon, 0 12px 11px 0 rgba(red, green, blue, 0.4);
}

button:active{
  transform: translate3d(0, 2px, 0);
  box-shadow: inset 0 20px 4px -20px salmon, 0 12px 11px 0 rgba(red, green, blue, 0.4);
}