@import url('https://fonts.googleapis.com/css?family=Yantramanav');

:root {
  --sf-width: 100vw;
  --sf-segments: 0;
  --sf-width-segment: calc(var(--sf-width)/var(--sf-segments));
  --sf-radius: 1.5vmin;
  --sf-rgb: 59, 182, 235;
  --sf-fontColor: 255, 255, 255;
  --sf-animationDirection: normal;
  --sf-margin: 1;
  --sf-speed: 1s;
}

.sf-container {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100vh;
  width: 100vw;
  position: absolute;
  top: 100x;
  left: 0;
}

.splitflap {
  min-width: var(--sf-width-segment);
  font-size: var(--sf-width-segment);
  line-height: var(--sf-width-segment);
  text-align: center;
  height: var(--sf-width-segment);
  /* color: rgb(var(--sf-fontColor)); */
  color: rgb(255,255,255);
  margin: calc(var(--sf-margin)*5px);
  perspective: 1000px;
  position: relative;
  font-family: 'Yantramanav', sans-serif;
  -webkit-transform: translate3D(0, 0, 0);
  border: 1.3px solid black;
  border-radius: var(--sf-radius);
  /* background-color: rgb(var(--sf-rgb)); */
  background: #000000;
}



.front-top {
  /* background-color: rgb(var(--sf-rgb)); */
  background: #1a1a1a;
  border-radius: var(--sf-radius) var(--sf-radius) 0 0;
  height: 50%;
  width: 100%;
  position: relative;
  overflow: hidden;
  z-index: -1;
}

.front-full {
  position: relative;
  height: 100%;
  width: 100%;
  margin-top: -50%;
  border-radius: var(--sf-radius) var(--sf-radius) var(--sf-radius) var(--sf-radius);
  z-index: -2;
  background-color: black;
  background-image: linear-gradient(rgba(var(--sf-rgb), 0), rgb(var(--sf-rgb)));
  transform-origin: center;
}

.front-top:after {
  position: absolute;
  top: 0;
  left: 0;
  content: "";
  height: 100%;
  width: 100%;
  border-bottom: 1px solid black;
  box-sizing: border-box;
}


.back-top {
  position: relative;
  height: 50%;
  width: 100%;
  /* background-color: rgb(var(--sf-rgb)); */
  background: #1a1a1a;
  margin-top: -100%;
  overflow: hidden;
  border-radius: var(--sf-radius) var(--sf-radius) 0 0;
  z-index: 2;
  background-image: linear-gradient(rgb(var(--sf-rgb)), rgba(var(--sf-rgb), 1));
  transform-origin: bottom;
  transform: rotateX(-90deg);
}

.back-top:after {
  position: absolute;
  top: 0;
  left: 0;
  content: "";
  border-bottom: 1px solid black;
  box-sizing: border-box;
  height: 100%;
  width: 100%;
}

.back-full {
  position: relative;
  height: 100%;
  width: 100%;
  /* background-color: rgb(var(--sf-rgb)); */
  background: #000000;
  margin-top: -50%;
  border-radius: var(--sf-radius) var(--sf-radius) var(--sf-radius) var(--sf-radius);
  z-index: -3;
}

.flip1 {
  animation: flip1 ease-in;
  animation-fill-mode: forwards;
  animation-direction: var(--sf-animationDirection);
  animation-duration: var(--sf-speed);
}

.flip2 {
  animation: flip2 ease-out;
  animation-fill-mode: forwards;
  animation-direction: var(--sf-animationDirection);
  animation-duration: var(--sf-speed);
}

@keyframes flip1 {
  0% {
    transform: rotateX(0deg);
  /* background-color: rgb(var(--sf-rgb)); */
  background: #181818;
  }
  50% {
    transform: rotateX(90deg);
    background-color: black;
  }
  100% {
    transform: rotateX(90deg);
  }
}

@keyframes flip2 {
  0% {
    transform: rotateX(-90deg);
  }
  50% {
    transform: rotateX(-90deg);
  }
  100% {
    transform: rotateX(0deg);
  /* background-color: rgb(var(--sf-rgb)); */
  background: #202020;
  }
}

.splitflap:nth-child(even) {
  margin-left: calc(-6px * var(--sf-margin));
}