style.css

*{
  margin: 0;
  padding: 0;
}

body{
  font-family: 'Roboto', sans-serif;
  font-size: 1.5vw;
}

main{
  display: flex;
  justify-content: center;
  align-items: center;
  flex-direction: column;
  height: 100vh;
  width: 100vw;
  background-color: antiquewhite;
}

.chessboard {
  border: 1px solid #a19e9c;
  width: 40vw;
  height: 40vw;
  display: grid;
  grid-template-columns: 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr;
  grid-template-rows: 1fr 1fr 1fr 1fr 1fr 1fr 1fr 1fr;
}

.square{
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
  width: 100%;
  height: 100%;
}

.white {
  background-color: #b2a9a0;
}

.black {
  background-color: #eee9e6;
}

.blocked::before{
  content: '';
  display: block;
  position: absolute;
  width: 100%;
  height: 100%;
  background-color: red;
  opacity: 25%;
}

.queen{
  width: 70%;
}

.queen img{
  width: 100%;
  height: 100%;
}

#easy-btn{
  font-size: 0.8em;
  color: white;
  cursor: pointer;
  margin: 0.5vw;
  border: none;
  padding: 4px 16px;
  border-radius: 10px;
}

#easy-btn.on{
  background-color: green;
}

#easy-btn.off{
  background-color: red;
}