* {
  padding: 0;
  margin: 0;
  box-sizing: border-box;
}

body {
  margin: 0 auto;
  background-color: var(--color-00);
  overflow-x: hidden;
  font-family: "Oswald", sans-serif;
  font-family: "Permanent Marker", cursive;
  background: url("./img/background.jpg") no-repeat center top fixed;
  -webkit-background-size: cover;
  -moz-background-size: cover;
  -o-background-size: cover;
  background-size: cover;
}

:root {
  --dark-green: rgba(3, 42, 24, 0.7);
  --light-green: #669374;
  --light-sand: #cab7b3;
  --sand: #deb69d;
  --light-brown: #8f6b5f;
}

@keyframes hide {
  0% {
    opacity: 1;
  }
  100% {
    opacity: 0;
  }
}

@keyframes fade {
  0% {
    opacity: 0.7;
  }
  100% {
    opacity: 1;
  }
}

.modal {
  animation: fade 0.6s linear;
  animation-fill-mode: forwards;
}

.modal,
.game__number {
  position: absolute;
  max-width: 400px;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  background-color: var(--light-green);
  color: var(--light-sand);
  text-shadow: 2px 2px 5px var(--dark-green);
  text-transform: uppercase;
  font-size: 1.6em;
  text-align: center;
  padding: 15px;
  border-radius: 1em;
  box-shadow: 2px 2px 5px var(--dark-green);
}

.modal {
  background-color: var(--light-brown);
  color: var(--light-sand);
}

.game__number__input {
  margin-left: 10px;
  width: 60%;
  height: 100%;
  color: var(--dark-green);
  font-size: 1em;
  text-align: center;
  border-radius: 1em;
  box-shadow: inset 2px 2px 5px var(--dark-green);
}

.header__main {
  height: 80px;
  text-align: center;
  font-size: 1.2em;
  padding-top: 20px;
  color: var(--light-sand);
  text-shadow: 5px 5px 15px var(--dark-green);
  border-bottom: var(--light-green) 2px solid;
}

.game__info {
  display: flex;
  justify-content: space-around;
  max-width: 500px;
  height: min(80px, 15vh);
  margin: 0 auto;
  padding: 20px;
}

.level {
  padding-top: 5px;
  font-family: "Oswald", sans-serif;
  text-align: center;
}

.game__info button,
.level {
  width: 20%;
  height: 50px;
  border: 2px solid var(--light-sand);
  border-radius: 15px;
  background-color: var(--light-green);
  color: var(--light-sand);
  font-size: 1.2em;
  box-shadow: 3px 3px 1px 1px rgba(var(--dark-green), 0.5);
}

.game__info button:hover {
  color: var(--light-green);
  background-color: var(--light-sand);
}

.game__info button:active {
  color: var(--light-green);
  background-color: var(--light-sand);
  border: 5px solid var(--light-brown);
  box-shadow: 0px 0px 1px 1px var(--dark-green);
}

.game__wrap {
  margin: 20px auto;
  max-width: 500px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  grid-column-gap: 10px;
  grid-row-gap: 10px;
  justify-items: center;
}

.round {
  transform: rotateY(180deg);
}

.hidden {
  -webkit-animation: hide 0.6s linear;
  -moz-animation: hide 0.6s linear;
  -o-animation: hide 0.6s linear;
  animation: hide 0.6s linear;
  animation-fill-mode: forwards;
  -moz-animation-fill-mode: forwards;
  transition: all 0.6s linear;
  --webkit-transition: all 0.6s linear;
}

.flip-container,
.front,
.back {
  width: 100px;
  height: 140px;
}

.flipper {
  transition: 0.6s;
  --webkit-transition: 0.6s;
  -webkit-transition: 0.6s;
  --moz-transition: 0.6s;
  transform-style: preserve-3d;
  position: relative;
}

.front,
.back {
  backface-visibility: hidden;
  position: absolute;
  top: 0;
  left: 0;
  border: 3px solid var(--light-green);
  border-radius: 15px;
  box-shadow: 1px 1px 5px var(--dark-green);
}

.front {
  background-color: var(--light-sand);
  z-index: 2;
  transform: rotateY(0deg);
}

.img__back {
  display: block;
  height: 100%;
  width: 100%;
  margin: 0 auto;
  border-radius: 15px;
}

.back {
  transform: rotateY(180deg);
}

@media screen and (max-width: 640px) {
  .game__wrap {
    grid-template-columns: repeat(3, 1fr);
    max-width: 400px;
  }
}

@media screen and (max-width: 360px) {
  .game__wrap {
    grid-template-columns: repeat(2, 1fr);
    max-width: 250px;
  }

  .header__main,
  .game__info {
    font-size: 0.8em;
  }
}