@import "fonts/clear-sans.css";
:root {
  --bg-gradient: linear-gradient(135deg, #e8e4f0 0%, #f5f0fa 50%, #eef0f5 100%);
  --bg-color: #f0ecf5;
  --text-color: #3d3565;
  --tile-color: #e8e0f0;
  --tile-text: #3d3565;
  --tile-gold: #e8b830;
  --tile-gold-glow: #ffe066;
  --game-bg: rgba(255, 255, 255, 0.75);
  --button-bg: #6c5c8a;
  --button-bg-hover: #7c6c9a;
  --grid-cell-bg: rgba(60, 40, 100, 0.08);
  --score-bg: rgba(60, 40, 100, 0.15);
  --score-label: rgba(60, 40, 100, 0.6);
  --score-text: #3d3565;
  --score-addition: rgba(60, 40, 100, 0.9);
  --game-overlay-bg: rgba(255, 255, 255, 0.6);
  --win-overlay-bg: rgba(232, 184, 48, 0.3);
  --link-color: #6c5c8a;
  --hr-color: rgba(60, 40, 100, 0.15);
  --theme-color: #f0ecf5;
  --tile-shadow: 0 2px 8px rgba(60, 40, 100, 0.15);
  --tile-2048-glow: 0 0 20px rgba(232, 184, 48, 0.3);
  --bright-text-color: #f9f6f2;
  --container-bg: rgba(255, 255, 255, 0.6);
  --container-border: rgba(255, 255, 255, 0.8);
  --container-shadow: 0 2px 20px rgba(60, 40, 100, 0.08);
  --title-gradient: linear-gradient(135deg, #6c5c8a, #4a3a6a);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg-gradient: linear-gradient(135deg, #0a0a1a 0%, #140a2a 50%, #0e0e22 100%);
    --bg-color: #0a0a1a;
    --text-color: #d8d0e8;
    --tile-color: #2a2a4a;
    --tile-text: #d8d0e8;
    --tile-gold: #e8b830;
    --tile-gold-glow: #ffe066;
    --game-bg: rgba(255, 255, 255, 0.06);
    --button-bg: #4a3a6a;
    --button-bg-hover: #5a4a7a;
    --grid-cell-bg: rgba(255, 255, 255, 0.06);
    --score-bg: rgba(255, 255, 255, 0.08);
    --score-label: rgba(255, 255, 255, 0.5);
    --score-text: #d8d0e8;
    --score-addition: rgba(216, 208, 232, 0.9);
    --game-overlay-bg: rgba(10, 10, 26, 0.7);
    --win-overlay-bg: rgba(232, 184, 48, 0.15);
    --link-color: #a898c8;
    --hr-color: rgba(255, 255, 255, 0.08);
    --theme-color: #0a0a1a;
    --tile-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
    --tile-2048-glow: 0 0 30px rgba(232, 184, 48, 0.4);
    --bright-text-color: #f9f6f2;
    --container-bg: rgba(255, 255, 255, 0.04);
    --container-border: rgba(255, 255, 255, 0.08);
    --container-shadow: 0 2px 20px rgba(0, 0, 0, 0.2);
    --title-gradient: linear-gradient(135deg, #a898c8, #c8b8e8);
  }
  .tile-2 .tile-inner {
    background: #1e1e3e !important;
    color: #c8c0d8 !important;
    box-shadow: none !important;
  }
  .tile-4 .tile-inner {
    background: #2a1e4e !important;
    color: #c8c0d8 !important;
    box-shadow: none !important;
  }
  .tile-8 .tile-inner {
    background: #3a1e5e !important;
    color: #f0ecf5 !important;
    box-shadow: none !important;
  }
  .tile-16 .tile-inner {
    background: #5a1e7e !important;
    color: #f0ecf5 !important;
    box-shadow: none !important;
  }
  .tile-32 .tile-inner {
    background: #7a1e6e !important;
    color: #f0ecf5 !important;
    box-shadow: none !important;
  }
  .tile-64 .tile-inner {
    background: #9a1e4e !important;
    color: #f0ecf5 !important;
    box-shadow: none !important;
  }
  .tile-128 .tile-inner {
    background: #b88a2e !important;
    color: #f0ecf5 !important;
    box-shadow: 0 0 10px rgba(232, 184, 48, 0.2) !important;
  }
  .tile-256 .tile-inner {
    background: #c89a2e !important;
    color: #f0ecf5 !important;
    box-shadow: 0 0 12px rgba(232, 184, 48, 0.25) !important;
  }
  .tile-512 .tile-inner {
    background: #d8aa2e !important;
    color: #f0ecf5 !important;
    box-shadow: 0 0 14px rgba(232, 184, 48, 0.3) !important;
  }
  .tile-1024 .tile-inner {
    background: #e8ba2e !important;
    color: #1a1a2e !important;
    box-shadow: 0 0 18px rgba(232, 184, 48, 0.35) !important;
  }
  .tile-2048 .tile-inner {
    background: #f0c830 !important;
    color: #1a1a2e !important;
    box-shadow: 0 0 30px rgba(232, 184, 48, 0.5) !important;
  }
  .tile-super .tile-inner {
    background: #1a1a2e !important;
    color: #e8b830 !important;
  }
}
html, body {
  margin: 0;
  padding: 0;
  background: var(--bg-gradient);
  background-attachment: fixed;
  color: var(--text-color);
  font-family: "Clear Sans", "Helvetica Neue", Arial, sans-serif;
  font-size: 18px;
}

body {
  margin: 60px 0;
  min-height: 100vh;
}

.heading:after {
  content: "";
  display: block;
  clear: both;
}

h1.title {
  font-size: 80px;
  font-weight: bold;
  margin: 0;
  display: block;
  float: left;
  background: var(--title-gradient, none);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

@-webkit-keyframes $animation-name {
  0% {
    top: 25px;
    opacity: 1;
  }
  100% {
    top: -50px;
    opacity: 0;
  }
}
@-moz-keyframes $animation-name {
  0% {
    top: 25px;
    opacity: 1;
  }
  100% {
    top: -50px;
    opacity: 0;
  }
}
@keyframes $animation-name {
  0% {
    top: 25px;
    opacity: 1;
  }
  100% {
    top: -50px;
    opacity: 0;
  }
}
.scores-container {
  float: right;
  text-align: right;
}

.score-container, .best-container {
  position: relative;
  display: inline-block;
  background: var(--score-bg);
  padding: 15px 25px;
  font-size: 25px;
  height: 25px;
  line-height: 47px;
  font-weight: bold;
  border-radius: 10px;
  color: var(--score-text);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  margin-top: 8px;
  text-align: center;
}
.score-container:after, .best-container:after {
  position: absolute;
  width: 100%;
  top: 10px;
  left: 0;
  text-transform: uppercase;
  font-size: 13px;
  line-height: 13px;
  text-align: center;
  color: var(--score-label);
}
.score-container .score-addition, .best-container .score-addition {
  position: absolute;
  right: 30px;
  color: var(--score-addition);
  font-size: 25px;
  line-height: 25px;
  font-weight: bold;
  z-index: 100;
  -webkit-animation: move-up 600ms ease-in;
  -moz-animation: move-up 600ms ease-in;
  animation: move-up 600ms ease-in;
  -webkit-animation-fill-mode: both;
  -moz-animation-fill-mode: both;
  animation-fill-mode: both;
}

.score-container:after {
  content: "分数";
}

.best-container:after {
  content: "最高";
}

p {
  margin-top: 0;
  margin-bottom: 10px;
  line-height: 1.65;
}

a {
  color: var(--link-color);
  font-weight: bold;
  text-decoration: underline;
  cursor: pointer;
}

strong.important {
  text-transform: uppercase;
}

hr {
  border: none;
  border-bottom: 1px solid var(--hr-color);
  margin-top: 20px;
  margin-bottom: 30px;
}

.container {
  width: 500px;
  margin: 0 auto;
  padding: 20px 30px 30px;
  background: var(--container-bg, transparent);
  border-radius: 16px;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--container-border, transparent);
  box-shadow: var(--container-shadow, none);
}

@-webkit-keyframes $animation-name {
  0% {
    opacity: 0;
  }
  100% {
    opacity: 1;
  }
}
@-moz-keyframes $animation-name {
  0% {
    opacity: 0;
  }
  100% {
    opacity: 1;
  }
}
@keyframes $animation-name {
  0% {
    opacity: 0;
  }
  100% {
    opacity: 1;
  }
}
.game-container {
  margin-top: 40px;
  position: relative;
  padding: 15px;
  box-shadow: var(--game-shadow);
  cursor: default;
  -webkit-touch-callout: none;
  -ms-touch-callout: none;
  -webkit-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  -ms-touch-action: none;
  touch-action: none;
  background: var(--game-bg);
  border-radius: 12px;
  width: 500px;
  height: 500px;
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  box-sizing: border-box;
}
.game-container .game-message {
  display: none;
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  background: var(--game-overlay-bg);
  z-index: 100;
  text-align: center;
}
.game-container .game-message p {
  font-size: 60px;
  font-weight: bold;
  height: 60px;
  line-height: 60px;
  margin-top: 222px;
  color: var(--text-color);
}
.game-container .game-message .lower {
  display: block;
  margin-top: 59px;
}
.game-container .game-message a {
  display: inline-block;
  background: var(--button-bg);
  border-radius: 3px;
  padding: 0 20px;
  text-decoration: none;
  color: var(--bright-text-color);
  height: 40px;
  line-height: 42px;
  cursor: pointer;
  transition: background 150ms ease;
}
.game-container .game-message a:hover {
  background: var(--button-bg-hover);
}
.game-container .game-message a.undo-disabled {
  opacity: 0.4;
  cursor: not-allowed;
  pointer-events: none;
}
.game-container .game-message a {
  margin-left: 9px;
}
.game-container .game-message a.keep-playing-button {
  display: none;
}
.game-container .game-message {
  -webkit-animation: fade-in 800ms ease 1200ms;
  -moz-animation: fade-in 800ms ease 1200ms;
  animation: fade-in 800ms ease 1200ms;
  -webkit-animation-fill-mode: both;
  -moz-animation-fill-mode: both;
  animation-fill-mode: both;
}
.game-container .game-message.game-won {
  background: var(--win-overlay-bg);
  color: var(--bright-text-color);
}
.game-container .game-message.game-won a.keep-playing-button {
  display: inline-block;
}
.game-container .game-message.game-won, .game-container .game-message.game-over {
  display: block;
}

.grid-container {
  position: absolute;
  z-index: 1;
}

.grid-row {
  margin-bottom: 15px;
}
.grid-row:last-child {
  margin-bottom: 0;
}
.grid-row:after {
  content: "";
  display: block;
  clear: both;
}

.grid-cell {
  width: 106.25px;
  height: 106.25px;
  margin-right: 15px;
  float: left;
  border-radius: 8px;
  background: var(--grid-cell-bg);
}
.grid-cell:last-child {
  margin-right: 0;
}

.tile-container {
  position: absolute;
  z-index: 2;
}

.tile, .tile .tile-inner {
  width: 107px;
  height: 107px;
  line-height: 107px;
}
.tile.tile-position-1-1 {
  -webkit-transform: translate(0px, 0px);
  -moz-transform: translate(0px, 0px);
  -ms-transform: translate(0px, 0px);
  transform: translate(0px, 0px);
}
.tile.tile-position-1-2 {
  -webkit-transform: translate(0px, 121px);
  -moz-transform: translate(0px, 121px);
  -ms-transform: translate(0px, 121px);
  transform: translate(0px, 121px);
}
.tile.tile-position-1-3 {
  -webkit-transform: translate(0px, 242px);
  -moz-transform: translate(0px, 242px);
  -ms-transform: translate(0px, 242px);
  transform: translate(0px, 242px);
}
.tile.tile-position-1-4 {
  -webkit-transform: translate(0px, 363px);
  -moz-transform: translate(0px, 363px);
  -ms-transform: translate(0px, 363px);
  transform: translate(0px, 363px);
}
.tile.tile-position-2-1 {
  -webkit-transform: translate(121px, 0px);
  -moz-transform: translate(121px, 0px);
  -ms-transform: translate(121px, 0px);
  transform: translate(121px, 0px);
}
.tile.tile-position-2-2 {
  -webkit-transform: translate(121px, 121px);
  -moz-transform: translate(121px, 121px);
  -ms-transform: translate(121px, 121px);
  transform: translate(121px, 121px);
}
.tile.tile-position-2-3 {
  -webkit-transform: translate(121px, 242px);
  -moz-transform: translate(121px, 242px);
  -ms-transform: translate(121px, 242px);
  transform: translate(121px, 242px);
}
.tile.tile-position-2-4 {
  -webkit-transform: translate(121px, 363px);
  -moz-transform: translate(121px, 363px);
  -ms-transform: translate(121px, 363px);
  transform: translate(121px, 363px);
}
.tile.tile-position-3-1 {
  -webkit-transform: translate(242px, 0px);
  -moz-transform: translate(242px, 0px);
  -ms-transform: translate(242px, 0px);
  transform: translate(242px, 0px);
}
.tile.tile-position-3-2 {
  -webkit-transform: translate(242px, 121px);
  -moz-transform: translate(242px, 121px);
  -ms-transform: translate(242px, 121px);
  transform: translate(242px, 121px);
}
.tile.tile-position-3-3 {
  -webkit-transform: translate(242px, 242px);
  -moz-transform: translate(242px, 242px);
  -ms-transform: translate(242px, 242px);
  transform: translate(242px, 242px);
}
.tile.tile-position-3-4 {
  -webkit-transform: translate(242px, 363px);
  -moz-transform: translate(242px, 363px);
  -ms-transform: translate(242px, 363px);
  transform: translate(242px, 363px);
}
.tile.tile-position-4-1 {
  -webkit-transform: translate(363px, 0px);
  -moz-transform: translate(363px, 0px);
  -ms-transform: translate(363px, 0px);
  transform: translate(363px, 0px);
}
.tile.tile-position-4-2 {
  -webkit-transform: translate(363px, 121px);
  -moz-transform: translate(363px, 121px);
  -ms-transform: translate(363px, 121px);
  transform: translate(363px, 121px);
}
.tile.tile-position-4-3 {
  -webkit-transform: translate(363px, 242px);
  -moz-transform: translate(363px, 242px);
  -ms-transform: translate(363px, 242px);
  transform: translate(363px, 242px);
}
.tile.tile-position-4-4 {
  -webkit-transform: translate(363px, 363px);
  -moz-transform: translate(363px, 363px);
  -ms-transform: translate(363px, 363px);
  transform: translate(363px, 363px);
}

.tile {
  position: absolute;
}
.tile .tile-inner {
  border-radius: 8px;
  background: var(--tile-color);
  text-align: center;
  font-weight: bold;
  z-index: 10;
  font-size: 55px;
  box-shadow: var(--tile-shadow);
  color: var(--tile-text);
}
.tile {
  -webkit-transition: 100ms ease-in-out;
  -moz-transition: 100ms ease-in-out;
  transition: 100ms ease-in-out;
  -webkit-transition-property: -webkit-transform;
  -moz-transition-property: -moz-transform;
  transition-property: transform;
}
.tile.tile-2 .tile-inner {
  background: #eee4da;
  box-shadow: 0 0 30px 10px rgba(243.0660792952, 214.5572687225, 116.4339207048, 0), inset 0 0 0 1px rgba(255, 255, 255, 0);
}
.tile.tile-4 .tile-inner {
  background: rgb(237.9, 224.6, 200.8);
  box-shadow: 0 0 30px 10px rgba(243.0660792952, 214.5572687225, 116.4339207048, 0), inset 0 0 0 1px rgba(255, 255, 255, 0);
}
.tile.tile-8 .tile-inner {
  color: #f9f6f2;
  background: rgb(242.86, 177.64, 122.22);
}
.tile.tile-16 .tile-inner {
  color: #f9f6f2;
  background: rgb(245.565, 149.71, 100.18);
}
.tile.tile-32 .tile-inner {
  color: #f9f6f2;
  background: rgb(247.17, 124.53, 95.19);
}
.tile.tile-64 .tile-inner {
  color: #f9f6f2;
  background: rgb(247.125, 94.95, 59.4);
}
.tile.tile-128 .tile-inner {
  color: #f9f6f2;
  background: rgb(237.4, 207.6, 114.8);
  box-shadow: 0 0 30px 10px rgba(243.0660792952, 214.5572687225, 116.4339207048, 0.2380952381), inset 0 0 0 1px rgba(255, 255, 255, 0.1428571429);
  font-size: 45px;
}
@media screen and (max-width: 520px) {
  .tile.tile-128 .tile-inner {
    font-size: 25px;
  }
}
.tile.tile-256 .tile-inner {
  color: #f9f6f2;
  background: rgb(237.3, 204.2, 97.6);
  box-shadow: 0 0 30px 10px rgba(243.0660792952, 214.5572687225, 116.4339207048, 0.3174603175), inset 0 0 0 1px rgba(255, 255, 255, 0.1904761905);
  font-size: 45px;
}
@media screen and (max-width: 520px) {
  .tile.tile-256 .tile-inner {
    font-size: 25px;
  }
}
.tile.tile-512 .tile-inner {
  color: #f9f6f2;
  background: rgb(237.2, 200.8, 80.4);
  box-shadow: 0 0 30px 10px rgba(243.0660792952, 214.5572687225, 116.4339207048, 0.3968253968), inset 0 0 0 1px rgba(255, 255, 255, 0.2380952381);
  font-size: 45px;
}
@media screen and (max-width: 520px) {
  .tile.tile-512 .tile-inner {
    font-size: 25px;
  }
}
.tile.tile-1024 .tile-inner {
  color: #f9f6f2;
  background: rgb(237.1, 197.4, 63.2);
  box-shadow: 0 0 30px 10px rgba(243.0660792952, 214.5572687225, 116.4339207048, 0.4761904762), inset 0 0 0 1px rgba(255, 255, 255, 0.2857142857);
  font-size: 35px;
}
@media screen and (max-width: 520px) {
  .tile.tile-1024 .tile-inner {
    font-size: 15px;
  }
}
.tile.tile-2048 .tile-inner {
  color: #f9f6f2;
  background: #edc22e;
  box-shadow: 0 0 30px 10px rgba(243.0660792952, 214.5572687225, 116.4339207048, 0.5555555556), inset 0 0 0 1px rgba(255, 255, 255, 0.3333333333);
  font-size: 35px;
}
@media screen and (max-width: 520px) {
  .tile.tile-2048 .tile-inner {
    font-size: 15px;
  }
}
.tile.tile-super .tile-inner {
  color: #f9f6f2;
  background: rgb(60.3, 58.15, 50.75);
  font-size: 30px;
}
@media screen and (max-width: 520px) {
  .tile.tile-super .tile-inner {
    font-size: 10px;
  }
}

@-webkit-keyframes $animation-name {
  0% {
    opacity: 0;
    -webkit-transform: scale(0);
    -moz-transform: scale(0);
    -ms-transform: scale(0);
    transform: scale(0);
  }
  100% {
    opacity: 1;
    -webkit-transform: scale(1);
    -moz-transform: scale(1);
    -ms-transform: scale(1);
    transform: scale(1);
  }
}
@-moz-keyframes $animation-name {
  0% {
    opacity: 0;
    -webkit-transform: scale(0);
    -moz-transform: scale(0);
    -ms-transform: scale(0);
    transform: scale(0);
  }
  100% {
    opacity: 1;
    -webkit-transform: scale(1);
    -moz-transform: scale(1);
    -ms-transform: scale(1);
    transform: scale(1);
  }
}
@keyframes $animation-name {
  0% {
    opacity: 0;
    -webkit-transform: scale(0);
    -moz-transform: scale(0);
    -ms-transform: scale(0);
    transform: scale(0);
  }
  100% {
    opacity: 1;
    -webkit-transform: scale(1);
    -moz-transform: scale(1);
    -ms-transform: scale(1);
    transform: scale(1);
  }
}
.tile-new .tile-inner {
  -webkit-animation: appear 200ms ease 100ms;
  -moz-animation: appear 200ms ease 100ms;
  animation: appear 200ms ease 100ms;
  -webkit-animation-fill-mode: backwards;
  -moz-animation-fill-mode: backwards;
  animation-fill-mode: backwards;
}

@-webkit-keyframes $animation-name {
  0% {
    -webkit-transform: scale(0);
    -moz-transform: scale(0);
    -ms-transform: scale(0);
    transform: scale(0);
  }
  50% {
    -webkit-transform: scale(1.2);
    -moz-transform: scale(1.2);
    -ms-transform: scale(1.2);
    transform: scale(1.2);
  }
  100% {
    -webkit-transform: scale(1);
    -moz-transform: scale(1);
    -ms-transform: scale(1);
    transform: scale(1);
  }
}
@-moz-keyframes $animation-name {
  0% {
    -webkit-transform: scale(0);
    -moz-transform: scale(0);
    -ms-transform: scale(0);
    transform: scale(0);
  }
  50% {
    -webkit-transform: scale(1.2);
    -moz-transform: scale(1.2);
    -ms-transform: scale(1.2);
    transform: scale(1.2);
  }
  100% {
    -webkit-transform: scale(1);
    -moz-transform: scale(1);
    -ms-transform: scale(1);
    transform: scale(1);
  }
}
@keyframes $animation-name {
  0% {
    -webkit-transform: scale(0);
    -moz-transform: scale(0);
    -ms-transform: scale(0);
    transform: scale(0);
  }
  50% {
    -webkit-transform: scale(1.2);
    -moz-transform: scale(1.2);
    -ms-transform: scale(1.2);
    transform: scale(1.2);
  }
  100% {
    -webkit-transform: scale(1);
    -moz-transform: scale(1);
    -ms-transform: scale(1);
    transform: scale(1);
  }
}
.tile-merged .tile-inner {
  z-index: 20;
  -webkit-animation: pop 200ms ease 100ms;
  -moz-animation: pop 200ms ease 100ms;
  animation: pop 200ms ease 100ms;
  -webkit-animation-fill-mode: backwards;
  -moz-animation-fill-mode: backwards;
  animation-fill-mode: backwards;
}

.above-game:after {
  content: "";
  display: block;
  clear: both;
}

.game-intro {
  float: left;
  line-height: 42px;
  margin-bottom: 0;
}

.game-controls {
  float: right;
}
.game-controls .restart-button {
  display: inline-block;
  background: var(--button-bg);
  border-radius: 3px;
  padding: 0 20px;
  text-decoration: none;
  color: var(--bright-text-color);
  height: 40px;
  line-height: 42px;
  cursor: pointer;
  transition: background 150ms ease;
}
.game-controls .restart-button:hover {
  background: var(--button-bg-hover);
}
.game-controls .restart-button.undo-disabled {
  opacity: 0.4;
  cursor: not-allowed;
  pointer-events: none;
}
.game-controls .restart-button {
  display: inline-block;
  text-align: center;
  margin-left: 8px;
}
.game-controls .undo-button {
  display: inline-block;
  background: var(--button-bg);
  border-radius: 3px;
  padding: 0 20px;
  text-decoration: none;
  color: var(--bright-text-color);
  height: 40px;
  line-height: 42px;
  cursor: pointer;
  transition: background 150ms ease;
  white-space: nowrap;
  font-size: 14px;
}
.game-controls .undo-button:hover {
  background: var(--button-bg-hover);
}
.game-controls .undo-button.undo-disabled {
  opacity: 0.4;
  cursor: not-allowed;
  pointer-events: none;
}
.game-controls .undo-button {
  display: inline-block;
  text-align: center;
  min-width: 80px;
}
.game-controls .undo-button.undo-disabled {
  opacity: 0.4;
  cursor: not-allowed;
  pointer-events: none;
}

.restart-button {
  display: inline-block;
  background: var(--button-bg);
  border-radius: 3px;
  padding: 0 20px;
  text-decoration: none;
  color: var(--bright-text-color);
  height: 40px;
  line-height: 42px;
  cursor: pointer;
  transition: background 150ms ease;
  white-space: nowrap;
  font-size: 14px;
}
.restart-button:hover {
  background: var(--button-bg-hover);
}
.restart-button.undo-disabled {
  opacity: 0.4;
  cursor: not-allowed;
  pointer-events: none;
}
.restart-button {
  display: block;
  text-align: center;
  float: right;
}

.game-explanation {
  margin-top: 50px;
}

.game-note {
  font-size: 14px;
  opacity: 0.8;
}

@media screen and (max-width: 520px) {
  html, body {
    font-size: 15px;
  }
  body {
    margin: 20px 0;
    padding: 0 20px;
  }
  h1.title {
    font-size: 27px;
    margin-top: 15px;
  }
  .container {
    width: 280px;
    margin: 0 auto;
  }
  .score-container, .best-container {
    margin-top: 0;
    padding: 15px 10px;
    min-width: 40px;
  }
  .heading {
    margin-bottom: 10px;
  }
  .game-intro {
    width: 55%;
    display: block;
    box-sizing: border-box;
    line-height: 1.65;
  }
  .game-controls {
    width: 42%;
    float: right;
  }
  .game-controls .undo-button, .game-controls .restart-button {
    width: 100%;
    padding: 0;
    display: block;
    box-sizing: border-box;
    margin-top: 2px;
    margin-left: 0;
  }
  .restart-button {
    width: 42%;
    padding: 0;
    display: block;
    box-sizing: border-box;
    margin-top: 2px;
  }
  .game-container {
    margin-top: 40px;
    position: relative;
    padding: 15px;
    cursor: default;
    -webkit-touch-callout: none;
    -ms-touch-callout: none;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    -ms-touch-action: none;
    touch-action: none;
    background: var(--game-bg);
    border-radius: 6px;
    width: 500px;
    height: 500px;
    -webkit-box-sizing: border-box;
    -moz-box-sizing: border-box;
    box-sizing: border-box;
  }
  .game-container .game-message {
    display: none;
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    background: var(--game-overlay-bg);
    z-index: 100;
    text-align: center;
  }
  .game-container .game-message p {
    font-size: 60px;
    font-weight: bold;
    height: 60px;
    line-height: 60px;
    margin-top: 222px;
  }
  .game-container .game-message .lower {
    display: block;
    margin-top: 59px;
  }
  .game-container .game-message a {
    display: inline-block;
    background: var(--button-bg);
    border-radius: 3px;
    padding: 0 20px;
    text-decoration: none;
    color: var(--bright-text-color);
    height: 40px;
    line-height: 42px;
    cursor: pointer;
    transition: background 150ms ease;
  }
  .game-container .game-message a:hover {
    background: var(--button-bg-hover);
  }
  .game-container .game-message a.undo-disabled {
    opacity: 0.4;
    cursor: not-allowed;
    pointer-events: none;
  }
  .game-container .game-message a {
    margin-left: 9px;
  }
  .game-container .game-message a.keep-playing-button {
    display: none;
  }
  .game-container .game-message {
    -webkit-animation: fade-in 800ms ease 1200ms;
    -moz-animation: fade-in 800ms ease 1200ms;
    animation: fade-in 800ms ease 1200ms;
    -webkit-animation-fill-mode: both;
    -moz-animation-fill-mode: both;
    animation-fill-mode: both;
  }
  .game-container .game-message.game-won {
    background: var(--win-overlay-bg);
    color: var(--bright-text-color);
  }
  .game-container .game-message.game-won a.keep-playing-button {
    display: inline-block;
  }
  .game-container .game-message.game-won, .game-container .game-message.game-over {
    display: block;
  }
  .grid-container {
    position: absolute;
    z-index: 1;
  }
  .grid-row {
    margin-bottom: 15px;
  }
  .grid-row:last-child {
    margin-bottom: 0;
  }
  .grid-row:after {
    content: "";
    display: block;
    clear: both;
  }
  .grid-cell {
    width: 106.25px;
    height: 106.25px;
    margin-right: 15px;
    float: left;
    border-radius: 3px;
    background: var(--grid-cell-bg);
  }
  .grid-cell:last-child {
    margin-right: 0;
  }
  .tile-container {
    position: absolute;
    z-index: 2;
  }
  .tile, .tile .tile-inner {
    width: 107px;
    height: 107px;
    line-height: 107px;
  }
  .tile.tile-position-1-1 {
    -webkit-transform: translate(0px, 0px);
    -moz-transform: translate(0px, 0px);
    -ms-transform: translate(0px, 0px);
    transform: translate(0px, 0px);
  }
  .tile.tile-position-1-2 {
    -webkit-transform: translate(0px, 121px);
    -moz-transform: translate(0px, 121px);
    -ms-transform: translate(0px, 121px);
    transform: translate(0px, 121px);
  }
  .tile.tile-position-1-3 {
    -webkit-transform: translate(0px, 242px);
    -moz-transform: translate(0px, 242px);
    -ms-transform: translate(0px, 242px);
    transform: translate(0px, 242px);
  }
  .tile.tile-position-1-4 {
    -webkit-transform: translate(0px, 363px);
    -moz-transform: translate(0px, 363px);
    -ms-transform: translate(0px, 363px);
    transform: translate(0px, 363px);
  }
  .tile.tile-position-2-1 {
    -webkit-transform: translate(121px, 0px);
    -moz-transform: translate(121px, 0px);
    -ms-transform: translate(121px, 0px);
    transform: translate(121px, 0px);
  }
  .tile.tile-position-2-2 {
    -webkit-transform: translate(121px, 121px);
    -moz-transform: translate(121px, 121px);
    -ms-transform: translate(121px, 121px);
    transform: translate(121px, 121px);
  }
  .tile.tile-position-2-3 {
    -webkit-transform: translate(121px, 242px);
    -moz-transform: translate(121px, 242px);
    -ms-transform: translate(121px, 242px);
    transform: translate(121px, 242px);
  }
  .tile.tile-position-2-4 {
    -webkit-transform: translate(121px, 363px);
    -moz-transform: translate(121px, 363px);
    -ms-transform: translate(121px, 363px);
    transform: translate(121px, 363px);
  }
  .tile.tile-position-3-1 {
    -webkit-transform: translate(242px, 0px);
    -moz-transform: translate(242px, 0px);
    -ms-transform: translate(242px, 0px);
    transform: translate(242px, 0px);
  }
  .tile.tile-position-3-2 {
    -webkit-transform: translate(242px, 121px);
    -moz-transform: translate(242px, 121px);
    -ms-transform: translate(242px, 121px);
    transform: translate(242px, 121px);
  }
  .tile.tile-position-3-3 {
    -webkit-transform: translate(242px, 242px);
    -moz-transform: translate(242px, 242px);
    -ms-transform: translate(242px, 242px);
    transform: translate(242px, 242px);
  }
  .tile.tile-position-3-4 {
    -webkit-transform: translate(242px, 363px);
    -moz-transform: translate(242px, 363px);
    -ms-transform: translate(242px, 363px);
    transform: translate(242px, 363px);
  }
  .tile.tile-position-4-1 {
    -webkit-transform: translate(363px, 0px);
    -moz-transform: translate(363px, 0px);
    -ms-transform: translate(363px, 0px);
    transform: translate(363px, 0px);
  }
  .tile.tile-position-4-2 {
    -webkit-transform: translate(363px, 121px);
    -moz-transform: translate(363px, 121px);
    -ms-transform: translate(363px, 121px);
    transform: translate(363px, 121px);
  }
  .tile.tile-position-4-3 {
    -webkit-transform: translate(363px, 242px);
    -moz-transform: translate(363px, 242px);
    -ms-transform: translate(363px, 242px);
    transform: translate(363px, 242px);
  }
  .tile.tile-position-4-4 {
    -webkit-transform: translate(363px, 363px);
    -moz-transform: translate(363px, 363px);
    -ms-transform: translate(363px, 363px);
    transform: translate(363px, 363px);
  }
  .tile .tile-inner {
    font-size: 35px;
  }
  .game-message p {
    font-size: 30px !important;
    height: 30px !important;
    line-height: 30px !important;
    margin-top: 90px !important;
  }
  .game-message .lower {
    margin-top: 30px !important;
  }
}

/*# sourceMappingURL=main.css.map */

.achievement-notification {
  position: fixed;
  top: 20px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--button-bg);
  color: #f9f6f2;
  padding: 12px 24px;
  border-radius: 8px;
  font-size: 16px;
  font-weight: bold;
  z-index: 1000;
  opacity: 0;
  transition: opacity 0.3s ease;
  pointer-events: none;
  white-space: nowrap;
}
.achievement-notification.show {
  opacity: 1;
}
@media screen and (max-width: 560px) {
  .achievement-notification {
    font-size: 14px;
    padding: 10px 18px;
    top: 10px;
  }
}

/* 9x9 theme: tile font sizes for desktop */
.tile .tile-inner { font-size: 44px; }
.tile.tile-128 .tile-inner,
.tile.tile-256 .tile-inner,
.tile.tile-512 .tile-inner { font-size: 34px; }
.tile.tile-1024 .tile-inner,
.tile.tile-2048 .tile-inner { font-size: 26px; }
.tile.tile-super .tile-inner { font-size: 22px; }