* {box-sizing: border-box;}
html, body {
  width: 100%;
  height: 100%;
  position: relative;
  overflow: hidden;
  margin: 0;
  font-family: sans-serif;
  color: #263238;
}

#board {
  width: 95vmin;
  height: 95vmin;

  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}
@media only screen and (max-width: 479px) {
  #modal {
    width: 90vmin;
    height: 90vmin;
  }
}
@media only screen and (min-width: 480px) {
  #modal {
    width: 85vmin;
    height: 85vmin;
  }
}
@media only screen and (min-width : 768px) {
  #modal {
    width: 82vmin;
    height: 82vmin;
  }
}
@media only screen and (min-width : 992px) {
  #modal {
    width: 78vmin;
    height: 78vmin;
  }
}
#modal {
  overflow: auto;

  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);

  background-color: white;
  z-index: 5;
  border: 2px solid #263238;
  text-align: center;

  transition: all 0.2s;
}
#winner, #play-again {
  display: none;
}
#modal button {
  padding: 1em;
  border-radius: 0.5em;
  border: 1px solid #64B5F6;
  background-color: white;
  transition: all 0.2s;
  font-size: 0.9em;
}
#modal button:hover {
  border: 2px solid #1565C0;
  padding: 1.5em;
}
#modal button:focus {
  outline: none;
}

#modal #bot-label {
  padding: 0.5em;
  background-color: #ECEFF1;
}