* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: "Gill Sans", "Gill Sans MT", Calibri, "Trebuchet MS", sans-serif;
}

html {
  font-size: 10px;
}

.background-music {
  height: 20px;
  margin-right: 20px;
}

body {
  background-image: url("../img/Bamboo-background_3840x2160.jpg");
  background-repeat: initial;
  height: 100%;
  font-family: Cambria, Cochin, Georgia, Times, "Times New Roman", serif;
  display: flex;
  justify-content: center;
  align-items: center;
  flex-direction: column;
}

header,
footer {
  position: fixed;
  z-index: 1;
  background-color: black;
  height: 3.5em;
  width: 100%;
}

header {
  top: 0;
}

footer {
  width: 100%;
  bottom: 0;
  display: flex;
  flex-direction: row-reverse;
  align-items: center;
}

/*MENU*/

#menu {
  height: 100%;
  background-image: url("../img/samurai-2556603_1280.png");
  background-repeat: no-repeat;
  background-size: contain;
  background-position: center;
}

/*BUTTONS*/
#buttons {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin: 3em 0;
  bottom: 10;
}

.btn {
  font-size: 2em;
  border: solid 1px rgba(0, 0, 0, 0.5);
  height: 100px;
  width: 100px;
  margin: 10px;
  padding: 10px;
  border-radius: 50%;
  background-color: black;
  color: red;
  cursor: pointer;
  display: flex;
  justify-content: center;
  align-items: center;
}
.btn:hover {
  border: 3px solid rgb(0, 0, 0);
  color: white;
  background-color: red;
  border: 1px solid red;
}

.main-btn {
  height: 150px;
  width: 150px;
}
.main-btn:hover {
  border: 3px solid rgba(0, 0, 0, 0);
}

/*GAME LOGO*/
#game-name {
  margin: 8em 0;
}

.game-name-img {
  margin: 80px 0px;
}

/*ICONS FOR KARATE MOVEMENTS*/

#moves-icons {
  margin: 15px 0;
  display: flex;
  justify-content: space-between;
  flex-wrap: nowrap;
}

.arrowkey-icon {
  background-color: rgba(255, 255, 255, 0.8);
  border-radius: 25%;
  height: 50px;
  margin: 20px;
  padding: 5px;
}

.arrowkey-icon.shuto {
  background-color: rgba(66, 221, 66, 0.521);
}

.arrowkey-icon.oizuki {
  background-color: rgba(224, 46, 46, 0.521);
}

.arrowkey-icon.mawashigeri {
  background-color: rgba(235, 180, 79, 0.575);
}

.arrowkey-icon.maegeri {
  background-color: rgba(87, 87, 223, 0.521);
}

#rules {
  /* position: absolute; */
  font-size: 3em;
  color: white;
  width: 65%;
  margin: 1em 1em 5em 1em;
  background-color: rgba(0, 0, 0, 0.8);
  padding: 25px;
  line-height: 1.45em;
}

#rules-last-phrase {
  font-size: 2em;
  text-align: center;
  line-height: 1.8;
}

.icon-presentation {
  justify-content: center;
  text-align: center;
  margin: 10px;
}

.hidden {
  visibility: hidden;
  display: none;
}

/*RESPONSIVENESS*/

@media (max-width: 750px) {
  html {
    font-size: 10px;
  }

  .game-name-img {
    width: 300px;
    margin: 5em 0;
  }

  #moves-icons {
    margin: 15px 0;
    display: flex;
    justify-content: space-around;
    flex-wrap: wrap;
  }
}

/*ANIMATIONS OF ELEMENTS*/

.slide-in-top {
  -webkit-animation: slide-in-top 0.8s cubic-bezier(0.25, 0.46, 0.45, 0.94) 1s
    both;
  animation: slide-in-top 0.8s cubic-bezier(0.25, 0.46, 0.45, 0.94) 1s both;
}
/* ----------------------------------------------
 * Generated by Animista on 2021-2-16 23:34:28
 * Licensed under FreeBSD License.
 * See http://animista.net/license for more info. 
 * w: http://animista.net, t: @cssanimista
 * ---------------------------------------------- */

/**
 * ----------------------------------------
 * animation slide-in-top
 * ----------------------------------------
 */
@-webkit-keyframes slide-in-top {
  0% {
    -webkit-transform: translateY(-1000px);
    transform: translateY(-1000px);
    opacity: 0;
  }
  100% {
    -webkit-transform: translateY(0);
    transform: translateY(0);
    opacity: 1;
  }
}
@keyframes slide-in-top {
  0% {
    -webkit-transform: translateY(-1000px);
    transform: translateY(-1000px);
    opacity: 0;
  }
  100% {
    -webkit-transform: translateY(0);
    transform: translateY(0);
    opacity: 1;
  }
}

.scale-in-center {
  -webkit-animation: scale-in-center 0.7s cubic-bezier(0.25, 0.46, 0.45, 0.94)
    1s both;
  animation: scale-in-center 0.7s cubic-bezier(0.25, 0.46, 0.45, 0.94) 1s both;
}

/* ----------------------------------------------
 * Generated by Animista on 2021-2-17 13:31:39
 * Licensed under FreeBSD License.
 * See http://animista.net/license for more info. 
 * w: http://animista.net, t: @cssanimista
 * ---------------------------------------------- */

/**
 * ----------------------------------------
 * animation scale-in-center
 * ----------------------------------------
 */
@-webkit-keyframes scale-in-center {
  0% {
    -webkit-transform: scale(0);
    transform: scale(0);
    opacity: 1;
  }
  100% {
    -webkit-transform: scale(1);
    transform: scale(1);
    opacity: 1;
  }
}
@keyframes scale-in-center {
  0% {
    -webkit-transform: scale(0);
    transform: scale(0);
    opacity: 1;
  }
  100% {
    -webkit-transform: scale(1);
    transform: scale(1);
    opacity: 1;
  }
}

.heartbeat {
  -webkit-animation: heartbeat 1.5s ease-in-out infinite both;
  animation: heartbeat 1.5s ease-in-out infinite both;
}

/* ----------------------------------------------
 * Generated by Animista on 2021-2-16 15:29:47
 * Licensed under FreeBSD License.
 * See http://animista.net/license for more info. 
 * w: http://animista.net, t: @cssanimista
 * ---------------------------------------------- */

/**
 * ----------------------------------------
 * animation heartbeat
 * ----------------------------------------
 */
@-webkit-keyframes heartbeat {
  from {
    -webkit-transform: scale(1);
    transform: scale(1);
    -webkit-transform-origin: center center;
    transform-origin: center center;
    -webkit-animation-timing-function: ease-out;
    animation-timing-function: ease-out;
  }
  10% {
    -webkit-transform: scale(0.91);
    transform: scale(0.91);
    -webkit-animation-timing-function: ease-in;
    animation-timing-function: ease-in;
  }
  17% {
    -webkit-transform: scale(0.98);
    transform: scale(0.98);
    -webkit-animation-timing-function: ease-out;
    animation-timing-function: ease-out;
  }
  33% {
    -webkit-transform: scale(0.87);
    transform: scale(0.87);
    -webkit-animation-timing-function: ease-in;
    animation-timing-function: ease-in;
  }
  45% {
    -webkit-transform: scale(1);
    transform: scale(1);
    -webkit-animation-timing-function: ease-out;
    animation-timing-function: ease-out;
  }
}
@keyframes heartbeat {
  from {
    -webkit-transform: scale(1);
    transform: scale(1);
    -webkit-transform-origin: center center;
    transform-origin: center center;
    -webkit-animation-timing-function: ease-out;
    animation-timing-function: ease-out;
  }
  10% {
    -webkit-transform: scale(0.91);
    transform: scale(0.91);
    -webkit-animation-timing-function: ease-in;
    animation-timing-function: ease-in;
  }
  17% {
    -webkit-transform: scale(0.98);
    transform: scale(0.98);
    -webkit-animation-timing-function: ease-out;
    animation-timing-function: ease-out;
  }
  33% {
    -webkit-transform: scale(0.87);
    transform: scale(0.87);
    -webkit-animation-timing-function: ease-in;
    animation-timing-function: ease-in;
  }
  45% {
    -webkit-transform: scale(1);
    transform: scale(1);
    -webkit-animation-timing-function: ease-out;
    animation-timing-function: ease-out;
  }
}