:root {
  --main-bg-color: #ffffff;
  --main-text-color: #000000;
  --heading-bg-color: #f7dc6f;
  --secondary-color: #a4a4a4;
  --front-img-color: #e0e0e0;
  --back-img-color: #d6eaf8;
  --game-start-bg-color: #e57373;
  --start-container-bg-color: rgba(3, 169, 244, 0.4);
}

.dark-theme {
  --main-bg-color: #121212;
  --main-text-color: #d3d3d3;
  --heading-bg-color: #3e4a61;
  --secondary-color: #2fb65c;
  --front-img-color: #1a1a1a;
  --back-img-color: #37474f;
  --game-start-bg-color: #2a6f97;
  --start-container-bg-color: rgba(2, 119, 189, 0.8);
}

body {
  font-family: Arial, Tahoma, sans-serif;
  position: relative;
  z-index: 1;
  background-color: var(--main-bg-color);
}
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

.game-start-container {
  position: fixed;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  z-index: 1000;
  background-color: var(--start-contianer-bg-color);
}

.game-start-container .game-start {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  background-color: var(--game-start-bg-color);
  padding: 15px 25px;
  text-align: center;
  border-radius: 8px;
  cursor: pointer;
}
.game-start-container .game-start h1 {
  font-size: 40px;
  color: var(--main-text-color);
  padding: 20px;
}
.game-start-container .game-start button {
  font-size: 24px;
  padding: 10px 20px;
  background-color: var(--main-bg-color);
  color: var(--main-text-color);
  border: none;
  cursor: pointer;
  display: block;
  margin: 20px auto;
}
.game-start-container #different-shapes-number {
  font-size: 18px;
  padding: 5px 10px;
  background-color: var(--main-bg-color);
  color: var(--main-text-color);
  border: none;
  cursor: pointer;
  display: block;
  margin: 0 auto;
}
.game-start-container label {
  font-size: 20px;
  color: var(--main-text-color);
  padding: 10px 20px;
  display: block;
}
#time-limit {
  font-size: 18px;
  padding: 5px 10px;
  background-color: var(--main-bg-color);
  color: var(--main-text-color);
  border: none;
  cursor: pointer;
  display: block;
  margin: 0 auto;
}
.previous-game-wrongs {
  font-size: 20px;
  color: var(--main-text-color);
  padding: 10px 20px;
  display: block;
}
.previous-game-wrongs span {
  font-size: 18px;
  padding: 5px 10px;
}
.game-main-container {
  color: var(--main-text-color);
  display: block;
  margin: 0 auto;
  min-height: 100vh;
  height: 100%;
  background-color: var(--main-bg-color);
}
.dark-light-toggle {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
}
.dark-light-toggle img {
  width: 40px;
  height: 40px;
  cursor: pointer;
}
.info-container {
  position: relative;
  width: 90%;
  max-width: 1080px;
  margin: 0 auto 0;
  overflow: hidden;
  padding: 20px;
  font-size: 24px;
  background-color: var(--heading-bg-color);
  border: 2px solid var(--secondary-color);
}
.info-container .time {
  float: left;
  width: 50%;
}
.info-container .tries {
  float: right;
  width: 50%;
  text-align: right;
}
.memory-blocks-container {
  display: flex;
  width: 90%;
  max-width: 1100px;
  flex-wrap: wrap;
  margin: 20px auto;
}
.memory-blocks-container .game-block {
  height: 200px;
  transition: transform 0.5s;
  transform-style: preserve-3d;
  cursor: pointer;
  position: relative;
  flex: 1 0 200px;
  justify-content: center;
  margin: 0 10px 20px;
}
.memory-blocks-container .game-block .front {
  background-color: var(--front-img-color);
  line-height: 200px;
}

.memory-blocks-container .game-block .front::after {
  content: "~(￣▽￣)~*";
  color: var(--secondary-text-color);
  font-size: 30px;
  font-weight: bold;
  text-align: center;
}

.dark-theme .memory-blocks-container .game-block .front::after {
  content: "(^人^)";
}
.memory-blocks-container .game-block .back {
  background-color: var(--back-img-color);
  transform: rotateY(180deg);
}
.memory-blocks-container .game-block .back img {
  width: 140px;
  height: 140px;
  margin-top: 30px;
}
.memory-blocks-container .game-block .face {
  position: absolute;
  width: 100%;
  height: 100%;
  text-align: center;
  backface-visibility: hidden;
  border: 5px solid var(--secondary-color);
}

.memory-blocks-container .flipped,
.memory-blocks-container .checked {
  pointer-events: none;
}
.memory-blocks-container .flipped .back {
  --webkit-transform: rotateY(0);
  --moz-transform: rotateY(0);
  transform: rotateY(0);
}
.memory-blocks-container .checked .back {
  --webkit-transform: rotateY(0);
  --moz-transform: rotateY(0);
  transform: rotateY(0);
}