style.css

@font-face {
  font-family: "TexGyreHerosRegular";
  src: url("./assets/fonts/texgyreheros-regular.otf") format("opentype");
}

* {
  /* behavioral settings */
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  box-sizing: border-box;
  /* fonts */
  font-family: "TexGyreHerosRegular";
  font-size: small;
  line-height: 120%;
}

html,
body {
  /* position, dimensions */
  position: absolute;
  width: 100%;
  height: 100%;
  margin: 0;
  padding: 0;
  /* behavioral settings */
  overflow: hidden;
  /* styles, colours */
  background-color: black;
}

canvas {
  /* behavioral settings */
  display: block;
}

.loadingclass {
  /* position, dimensions */
  position: absolute;
  width: 100%;
  height: 100%;
  /* behavioral settings */
  overflow: hidden;
  /* styles, colours */
  background-color: transparent;
}

#container {
  /* position, dimensions */
  position: absolute;
  width: 100%;
  height: 100%;
  /* behavioral settings */
  display: flex;
  align-items: center;
  justify-content: center;
}

.header {
  /* position, dimensions */
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  margin: 0px;
  padding: 10px;
  /* styles, colours */
  background: transparent;
}

.footer {
  /* position, dimensions */
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  margin: 0px;
  padding: 10px;
  /* styles, colours */
  background: transparent;
}

.item {
  /* position, dimensions */
  border: none;
  padding: 5px;
  /* behavioral settings */
  cursor: pointer;
  /* styles, colours */
  background: transparent;
  color: #808080;
  mix-blend-mode: difference;
  /* fonts */
  text-align: left;
}

.item:hover {
  color: white;
}

/* responsiveness */
@media only screen and (max-device-width: 480px) {
  .header,
  .footer {
    /* behavioral settings */
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    grid-gap: 0px;
  }
}