body {
  margin: 0;
  padding-top: 15px;
  height: 100vh;
  font-family: Helvetica, sans-serif;
  font-size: 16px;
}
body::after {
  content: "";
  background-image: url("tetris.jpg");
  background-repeat: no-repeat;
  background-attachment: fixed;
  background-size: cover;
  background-position: center;
  opacity: 0.2;
  top: 0;
  left: 0;
  bottom: 0;
  right: 0;
  position: absolute;
  z-index: -1;
}
.main {
  display: flex;
  flex-direction: column;
  align-items: center;
}
#start-button {
  margin: 20px auto;
  padding: 10px;
  font-size: 18px;
  font-weight: 800;
  background-color: rgba(255, 0, 0, 0.616);
}
.container {
  display: flex;
}
.grid {
  width: 200px;
  height: 400px;
  display: flex;
  flex-wrap: wrap;
  background-color: rgb(0, 14, 12);
  border: 5px solid gray;
}
.grid div {
  height: 20px;
  width: 20px;
}
.tetromino {
  background-color: blue;
}
.mini-grid {
  margin-left: 50px;
  width: 80px;
  height: 80px;
  display: flex;
  flex-wrap: wrap;
  background-color: rgb(0, 14, 12);
  border: 5px solid gray;
}
.mini-grid div {
  width: 20px;
  height: 20px;
}