body {
  height: 100%;
  width: 100vw;
  margin: 0;
  padding: 0;
}

h1 {
  margin: 0;
  text-align: center;
  width: 100%;
  height: 5rem;
  line-height: 5rem;
  background-color: gray;
}

.msg {
  text-align: center;
  width: 100%;
  margin-top: 2rem;
}

.container {
  display: flex;
  justify-content: center;
  margin-top: 2rem;
}

.game-container {
  display: flex;
  justify-content: center;
  align-items: center;
  width: 26rem;
  height: 26rem;
  flex-wrap: wrap;
}

.game-container > button {
  border: 2px solid black;
  height: 13rem;
  width: 13rem;
  text-align: center;
  line-height: 13rem;
  font-size: 1.25rem;
}

#red {
  border-right: none;
  border-bottom: none;
  background-color: red;
  border-top-left-radius: 100%;
}

#yellow {
  border-bottom: none;
  border-left: none;
  background-color: yellow;
  border-top-right-radius: 100%;
}

#green {
  border-right: none;
  border-top: none;
  background-color: green;
  border-bottom-left-radius: 100%;
}

#blue {
  border-top: none;
  border-left: none;
  background-color: blue;
  border-bottom-right-radius: 100%;
}

.msg2 {
  height: 10rem;
  width: 10rem;
  background-color: gray;
  border-radius: 50%;
  position: absolute;
  text-align: center;
  line-height: 10rem;
  font-size: 1.75rem;
}

#red:hover,
#green:hover,
#blue:hover,
#yellow:hover {
  opacity: 0.9;
}

#red:active,
#green:active,
#blue:active,
#yellow:active {
  border: 2px solid cadetblue;
  box-shadow: 1px 1px 7px cadetblue;
}

@media (max-width: 450px) {
  .game-container {
    margin-top: 2.5rem;
    width: 16rem;
    height: 16rem;
  }

  .game-container > button {
    height: 8rem;
    width: 8rem;
    line-height: 7rem;
    font-size: 1rem;
  }

  .msg2 {
    height: 5rem;
    width: 5rem;
    line-height: 5rem;
    font-size: 0.95rem;
  }

  .msg {
    margin-top: 1.5rem;
  }
}