style.css

* {
  position: relative;
  box-sizing: border-box;
}

html,
body {
  height: 100%;
}

html {
  background-color: #000;
}

body {
  overflow: hidden;
  color: rgba(255, 255, 255, 0.5);
  font-family: "Russo One", arial, sans-serif;
  line-height: 1.25;
  letter-spacing: 0.06em;
}

.hide {
  opacity: 0;
  visibility: hidden;
}

.remove {
  display: none !important;
}

.blur {
  filter: blur(12px);
}

.container {
  height: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
}

.loading-init {
  width: 100%;
  align-self: center;
  text-align: center;
  text-transform: uppercase;
}
.loading-init__header {
  font-size: 2.2em;
}
.loading-init__status {
  margin-top: 1em;
  font-size: 0.8em;
  opacity: 0.75;
}

.stage-container {
  overflow: hidden;
  box-sizing: initial;
  border: 1px solid #222;
  margin: -1px;
}
@media (max-width: 840px) {
  .stage-container {
    border: none;
    margin: 0;
  }
}

.canvas-container {
  width: 100%;
  height: 100%;
  transition: filter 0.3s;
}
.canvas-container canvas {
  position: absolute;
  mix-blend-mode: lighten;
  transform: translateZ(0);
}

.controls {
  position: absolute;
  top: 0;
  width: 100%;
  padding-bottom: 50px;
  display: flex;
  justify-content: space-between;
  transition: opacity 0.3s, visibility 0.3s;
}
@media (min-width: 840px) {
  .controls {
    visibility: visible;
  }
  .controls.hide:hover {
    opacity: 1;
  }
}

.menu {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  background-color: rgba(0, 0, 0, 0.42);
  transition: opacity 0.3s, visibility 0.3s;
}
.menu__inner-wrap {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  transition: opacity 0.3s;
}
.menu__header {
  margin-top: auto;
  margin-bottom: 8px;
  padding-top: 16px;
  font-size: 2em;
  text-transform: uppercase;
}
.menu__subheader {
  margin-bottom: auto;
  padding-bottom: 12px;
  font-size: 0.86em;
  opacity: 0.8;
}
.menu form {
  width: 100%;
  max-width: 400px;
  padding: 0 10px;
  overflow: auto;
  -webkit-overflow-scrolling: touch;
}
.menu .form-option {
  display: flex;
  align-items: center;
  margin: 16px 0;
  transition: opacity 0.3s;
}
.menu .form-option label {
  display: block;
  width: 50%;
  padding-right: 12px;
  text-align: right;
  text-transform: uppercase;
  -webkit-user-select: none;
     -moz-user-select: none;
      -ms-user-select: none;
          user-select: none;
}
.menu .form-option--select select {
  display: block;
  width: 50%;
  height: 30px;
  font-size: 1rem;
  font-family: "Russo One", arial, sans-serif;
  color: rgba(255, 255, 255, 0.5);
  letter-spacing: 0.06em;
  background-color: transparent;
  border: 1px solid rgba(255, 255, 255, 0.5);
}
.menu .form-option--select select option {
  background-color: black;
}
.menu .form-option--checkbox input {
  display: block;
  width: 26px;
  height: 26px;
  margin: 0;
  opacity: 0.5;
}
@media (max-width: 840px) {
  .menu .form-option select, .menu .form-option input {
    outline: none;
  }
}

.close-menu-btn {
  position: absolute;
  top: 0;
  right: 0;
}

.btn {
  opacity: 0.16;
  width: 50px;
  height: 50px;
  display: flex;
  -webkit-user-select: none;
     -moz-user-select: none;
      -ms-user-select: none;
          user-select: none;
  cursor: default;
  transition: opacity 0.3s;
}
.btn--bright {
  opacity: 0.5;
}
@media (min-width: 840px) {
  .btn:hover {
    opacity: 0.32;
  }
  .btn--bright:hover {
    opacity: 0.75;
  }
}
.btn svg {
  display: block;
  margin: auto;
}

.credits {
  margin-top: auto;
  margin-bottom: 10px;
  padding-top: 6px;
  font-size: 0.8em;
  opacity: 0.75;
}
.credits a {
  color: rgba(255, 255, 255, 0.5);
  text-decoration: none;
}
.credits a:hover, .credits a:active {
  color: rgba(255, 255, 255, 0.75);
  text-decoration: underline;
}

.help-modal {
  display: flex;
  justify-content: center;
  align-items: center;
  position: fixed;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  visibility: hidden;
  transition-property: visibility;
  transition-duration: 0.25s;
}
.help-modal__overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  opacity: 0;
  transition-property: opacity;
  transition-timing-function: ease-in;
  transition-duration: 0.25s;
}
.help-modal__dialog {
  display: flex;
  flex-direction: column;
  align-items: center;
  max-width: 400px;
  max-height: calc(100vh - 100px);
  margin: 10px;
  padding: 20px;
  border-radius: 0.3em;
  background-color: rgba(0, 0, 0, 0.4);
  opacity: 0;
  transform: scale(0.9, 0.9);
  transition-property: opacity, transform;
  transition-timing-function: ease-in;
  transition-duration: 0.25s;
}
@media (min-width: 840px) {
  .help-modal__dialog {
    font-size: 1.25rem;
    max-width: 500px;
  }
}
.help-modal__header {
  font-size: 1.75em;
  text-transform: uppercase;
  text-align: center;
}
.help-modal__body {
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
  margin: 1em 0;
  padding: 1em 0;
  border-top: 1px solid rgba(255, 255, 255, 0.25);
  border-bottom: 1px solid rgba(255, 255, 255, 0.25);
  line-height: 1.5;
  color: rgba(255, 255, 255, 0.75);
}
.help-modal__close-btn {
  flex-shrink: 0;
  outline: none;
  border: none;
  border-radius: 2px;
  padding: 0.25em 0.75em;
  margin-top: 0.36em;
  font-family: "Russo One", arial, sans-serif;
  font-size: 1em;
  color: rgba(255, 255, 255, 0.5);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  background-color: rgba(255, 255, 255, 0.25);
  transition: color 0.3s, background-color 0.3s;
}
.help-modal__close-btn:hover, .help-modal__close-btn:active, .help-modal__close-btn:focus {
  color: #FFF;
  background-color: #09F;
}
.help-modal.active {
  visibility: visible;
  transition-duration: 0.4s;
}
.help-modal.active .help-modal__overlay {
  opacity: 1;
  transition-timing-function: ease-out;
  transition-duration: 0.4s;
}
.help-modal.active .help-modal__dialog {
  opacity: 1;
  transform: scale(1, 1);
  transition-timing-function: ease-out;
  transition-duration: 0.4s;
}