styles.css

:root {
  --cell-size: 100px;
}

html, body {
  margin: 0;
  padding: 0;
  background: #909090;
  color: #000000;
  font-family: "Clear Sans", "Helvetica Neue", Arial, sans-serif;
}

body {
  margin: 10px;
}

.container {
  position: relative;
  max-width: 600px;
  width: 100%;
  min-width: 380px;
  margin: 0 auto;
  padding: 0;
}

.header {
  display: block;
  padding: 0;
}

h1 {
  font-size: min(8vw, 80px);
  font-weight: bold;
  margin: 0;
}

.summary {
  width: 100%;
  margin: 0;
  margin-bottom: 30px;
  padding: 0;
  text-align: right;
}

.last-tile-info {
  width: 470px;
  height: 110px;
  margin: 15px auto;
  display: block;
}
@media screen and (max-width: 600px)
{
  .last-tile-info {
    width: 285px;
    height: 66px;
    margin: 15px auto;
  }
}

.last-tile-tag {
  display: inline-block;
  margin-left: 200px;
  margin-top: 40px;
  text-align: right;
  vertical-align: middle;
  font-size: 24px;
  font-weight: bold;
}
@media screen and (max-width: 600px)
{
  .last-tile-tag {
    margin-left: 60px;
    margin-top: 20px;
  }
}

.last-tile {
  width: 100px;
  height: 100px;
  margin-bottom: 10px;
  float: right;
  border: 5px solid black;
  justify-content: center;
  align-items: center;
  font-size: 80px;
  font-weight: bold;
  text-align: center;
}
@media screen and (max-width: 600px)
{
  .last-tile {
    width: 60px;
    height: 60px;
    margin-bottom: 7px;
    border-width: 3px;
    font-size: 50px;
  }
}
.last-tile:after {
  content: "";
  display: block;
  clear: both;
}

#game {
  position: relative;
}

.grid {
  margin: 0 auto;
}

.grid-cell {
  margin-bottom: 10px;
  margin-right: 10px;
  float: left;
  border: 5px solid black;
  justify-content: center;
  align-items: center;
  font-weight: bold;
  text-align: center;
}
@media screen and (max-width: 600px)
{
  .grid-cell {
    margin-bottom: 7px;
    margin-right: 7px;
    border-width: 3px;
  }
}
.grid-cell:last-child {
  margin-right: 0px;
}

.cat2-0 {
  color: #ff4040; /* red */
}
.cat2-2 {
  color: #40c040; /* green */
}
.cat2-3 {
  color: #4040ff; /* blue */
}
.cat2-1 {
  color: #d0d000; /* yellow */
}
.cat2-4 {
  color: #d000d0; /* magenta */
}
.cat2-5 {
  color: #00d0d0; /* cyan */
}
.cat2-6 {
  color: #ff8000; /* orange */
}
.cat2-7 {
  color: #0080ff; /* sand blue */
}
.cat2-8 {
  color: #8000ff; /* purple */
}
.cat2-9 {
  color: #ff0080; /* hot pink */
}
.cat2-10 {
  color: #a0b040; /* olive */
}
.cat2-11 {
  color: #00f090; /* marine */
}

.enabled {
  background: #a0a0a0;
  border-color: #c0c0c0 #404040 #404040 #c0c0c0;
  cursor: pointer;
  text-shadow: -1px 0 black, 0 1px black, 1px 0 black, 0 -1px black;
}
.enabled:hover {
  border-color: #606060 #b0b0b0 #b0b0b0 #606060;
}
.enabled:active {
  border-color: #404040 #c0c0c0 #c0c0c0 #404040;
}
.disabled {
  background: transparent;
  border-color: transparent;
  cursor: not-allowed;
  text-shadow: -1px 0 black, 0 1px black, 1px 0 black, 0 -1px black;
}

.p1claimed {
  background: #f0f0f0;
  border-color: #a0a0a0 #ffffff #ffffff #a0a0a0;
  text-shadow: -1px 0 black, 0 1px black, 1px 0 black, 0 -1px black;
}
.p1claimed.last-tile {
  box-shadow: 0 0 10px 5px #000040;
  z-index: 1;
}

.p2claimed {
  background: #101010;
  border-color: #000000 #606060 #606060 #000000;
  text-shadow: -1px 0 white, 0 1px white, 1px 0 white, 0 -1px white;
}
.p2claimed.last-tile {
  box-shadow: 0 0 10px 5px #ffffc0;
  z-index: 1;
}

#settings {
  display: none;
  position: relative;
}
#settings img {
  position: absolute;
  top: 0px;
  right: 0px;
  cursor: pointer;
}

label {
  display: block;
  margin: 10px 0;
}

#links {
  position: absolute;
  top: 20px;
  right: 0px;
}
@media screen and (max-width: 600px)
{
  #links {
    top: 0px;
  }
}
#links img {
  cursor: pointer;
}

#gameStateMessage {
  display: none;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  margin: 0 auto;
  width: 300px;
  background-color: rgba(255, 255, 255, 0.7);
  border: 1px solid black;

  text-align: center;
  font-weight: bold;
  font-size: 40px;
}
@media screen and (max-width: 600px)
{
  #gameStateMessage {
    font-size: 25px;
    width: 180px;
  }
}

#restartButton {
  display: block;
  width: 300px;
  margin: 20px auto;
  background-color: #a0a0a0;
  color: white;
  border-color: #c0c0c0 #404040 #404040 #c0c0c0;
  border-width: 5px;
  font-size: 18px;
  font-weight: bold;
  padding: 5px;
  cursor: pointer;
}
#restartButton:hover {
  border: none; /* removes default shadow from button border */
  border: 5px solid black;
  border-color: #606060 #b0b0b0 #b0b0b0 #606060;
}
#restartButton:active {
  border-color: #404040 #c0c0c0 #c0c0c0 #404040;
}
@media screen and (max-width: 600px)
{
  #restartButton {
    margin: 13px auto;
    width: 180px;
    border-width: 3px;
  }
  #restartButton:hover {
    border-width: 3px;
  }
  #restartButton:active {
    border-width: 3px;
  }
}

#winning_collections {
  font-weight: bold;
}