style.css

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  color: #FFF;
  font-family: 'Trebuchet MS', 'Lucida Sans Unicode', 'Lucida Grande', 'Lucida Sans', Arial, sans-serif;
}

html {
  font-size: 62.5%;
}

body {
  background-color: #1b1b1b;
}

.game-container {
  height: 90vh;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  align-items: center;
}

.title-container {
  text-align: center;
  width: 51rem;
  border-bottom: 1px solid #3a3a3c;
}

.tile-container {
  width: 33rem;
  margin-bottom: 3rem;
}

.tile-container div {
  display: flex;
}

.tile-container .tile {
  width: 6.2rem;
  height: 6.2rem;
  border: 2px solid #3a3a3c;
  display: flex;
  justify-content: center;
  align-items: center;
  margin: 0.2rem;
  font-size: 2rem;
}

.keyboard-container {
  width: 55rem;
  display: flex;
  flex-wrap: wrap;
}

.keyboard-container button {
  width: 4.5rem;
  height: 4.5rem;
  border-radius: 0.4rem;
  border: none;
  background-color: #818384;
  margin: 0.4rem;
  font-size: 2rem;
}

.keyboard-container button:nth-child(28) {
  width: 7.5rem;
}

.message-container {
  height: 30px;
}

.message-container p {
  background-color: #818384;
  border-radius: 1rem;
  padding: 1rem;
}

@keyframes flipping{
  0%{
    transform: rotateX(0deg);
  }
  50%{
    transform: rotateX(90deg);
  }
  100%{
    transform: rotateX(0deg);
  }
}

.tile.flip{
  animation: 0.5s linear flipping;
}

.grey-overlay {
  background-color: #3a3a3c !important;
  border:none !important;
}
.yellow-overlay {
  background-color: #b59f3a !important;
  border:none !important;
}

.green-overlay {
  background-color: #538d4e !important;
  border:none !important;
}