* {
  margin: 0;
  padding: 0;
}


*, *::before, *::after {
  box-sizing: inherit;
}

html {
  box-sizing: border-box;
  font-size: 62.5%;
  scroll-behavior: smooth;
  font-family: "Noto Serif JP", 'Courier New';
}

body {
  display: flex;
  justify-content: center; 
  align-items: center;
  height: 100vh;      
}


.page {
  position: relative; /*this make the child elements (whose position's set to absolute) stay inside the parent element(this)*/
  border: 0.1rem solid black;
  width: 130rem;
  height: 100%;
  display: flex;
  overflow: hidden;
}

.page * {
  
  max-width: 100vw;
  max-height: 100vh;
  margin: 0 auto;
}

#background, #sprite-div {
  
  
}

/*----SPRITE-----*/

#background, #sprite-div > div > * {
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  
}

#background {
  z-index: 0;
}


#sprite-div {
  z-index: 2;
}

#noise {
  z-index: 3;
}

.hide {
  display: none;
}


.disappear {
  animation-name: disappear;
  animation-duration: 0.2s;
  animation-iteration-count: 1;
  animation-timing-function: linear;
}

.appear {
  animation-name: appear;
  animation-duration: 0.2s;
  animation-iteration-count: 1;
  animation-timing-function: linear;
}

@keyframes disappear {
  0%   { filter: blur(0) contrast(1); }
  50%  { filter: blur(0.3rem) contrast(10) invert(1); }
  100% { filter: blur(1rem); contrast(2) invert(1);}
}

@keyframes appear {
  0%   { filter: blur(1rem) contrast(2) invert(1); }
  50%  { filter: blur(0.3rem) contrast(10) invert(1); }
  100% { filter: blur(0) contrast(1); }
}

/*----SPRITE-----*/

/*----button-----*/
.button-tab-row {
  width: 15rem;
  height: 100vh;
  position: absolute;
  left: 15%;
  transform: translateX(-50%);
  z-index: 100;
  display: flex;
  flex-direction: column;
  justify-content: space-evenly;
}

.button-tab {
  width: 15rem;
  height: 100%;
  max-height: 70rem;
  display: flex;
  flex-direction: column;
  justify-content: space-evenly;
}

.button-tab > div > button, .button-tab > div  {
  height: 100%;
  width: 100%;
  max-width: 15rem;
  max-height: 15rem;
}

.button-tab > div > button {
  background-color: #fff;
  color: #000;
  border-color: #000;
  font-size: 5rem;
  font-family: "Noto Serif JP", 'Courier New';
}

.button-tab > div > button:hover {
  background-color: #B71B1B;
  color: #fff;
}