.d20-page {
  width: 100%;
  text-align: center;

  --d20-color: #8a0f23;
  --d20-outline: #5e0918;
  --d20-number-color: #f8eee8;
  --d20-font: Georgia, "Times New Roman", serif;
}

/* --------------------------------------------------
   Page
-------------------------------------------------- */

.d20-page h1 {
  font-family: var(--d20-font);
  font-weight: normal;
}

/* --------------------------------------------------
   Dice container
-------------------------------------------------- */

.d20-content {
  position: relative;

  width: 280px;
  height: 280px;

  margin: 40px auto 20px;

  perspective: 1500px;
}

/* --------------------------------------------------
   Die
-------------------------------------------------- */

.d20-die {
  position: absolute;

  top: 40px;
  left: 40px;

  width: 200px;
  height: 200px;

  transform-style: preserve-3d;

  transform: rotateX(-53deg);

  transition: transform 0.5s;

  cursor: pointer;

  counter-reset: face;
}

.d20-die.rolling {
  animation: d20-roll 3s linear;
}

/* --------------------------------------------------
   Roll animation
-------------------------------------------------- */

@keyframes d20-roll {
  10% {
    transform:
      rotateX(0deg)
      rotateY(0deg)
      rotateZ(0deg);
  }

  30% {
    transform:
      rotateX(120deg)
      rotateY(240deg)
      rotateZ(0deg)
      translateX(40px)
      translateY(40px);
  }

  50% {
    transform:
      rotateX(240deg)
      rotateY(480deg)
      rotateZ(0deg)
      translateX(-40px)
      translateY(-40px);
  }

  70% {
    transform:
      rotateX(360deg)
      rotateY(720deg)
      rotateZ(0deg);
  }

  90% {
    transform:
      rotateX(480deg)
      rotateY(960deg)
      rotateZ(0deg);
  }
}

/* --------------------------------------------------
   Triangle faces
-------------------------------------------------- */

.d20-face {
  position: absolute;

  width: 100px;
  height: 86px;

  margin: 0;

  left: 50px;
  top: 57px;

  box-sizing: border-box;

  background: var(--d20-color);

  clip-path: polygon(
    50% 0%,
    100% 100%,
    0% 100%
  );

  backface-visibility: hidden;

  counter-increment: face;
}

/* --------------------------------------------------
   Face outline
-------------------------------------------------- */

.d20-face::after {
  content: "";

  position: absolute;

  left: -2px;
  top: -2px;

  width: 104px;
  height: 90px;

  background: var(--d20-outline);

  clip-path: polygon(
    50% 0%,
    100% 100%,
    0% 100%
  );

  z-index: -1;
}

/* --------------------------------------------------
   Numbers
-------------------------------------------------- */

.d20-face::before {
  content: counter(face);

  position: absolute;

  left: 5px;
  top: 7px;

  width: 90px;
  height: 75px;

  display: flex;

  align-items: center;
  justify-content: center;

  color: var(--d20-number-color);

  font-family: var(--d20-font);

  font-size: 25px;
  font-weight: bold;

  line-height: 1;

  text-align: center;

  clip-path: polygon(
    50% 0%,
    100% 100%,
    0% 100%
  );

  background: var(--d20-color);

  text-shadow: none;

  z-index: 2;
}

/* --------------------------------------------------
   Face positions
-------------------------------------------------- */

.d20-face:nth-child(1) {
  transform:
    rotateY(0deg)
    translateZ(33.5px)
    translateY(-12.9px)
    rotateX(53deg);
}

.d20-face:nth-child(2) {
  transform:
    rotateY(-72deg)
    translateZ(33.5px)
    translateY(-12.9px)
    rotateX(53deg);
}

.d20-face:nth-child(3) {
  transform:
    rotateY(-144deg)
    translateZ(33.5px)
    translateY(-12.9px)
    rotateX(53deg);
}

.d20-face:nth-child(4) {
  transform:
    rotateY(-216deg)
    translateZ(33.5px)
    translateY(-12.9px)
    rotateX(53deg);
}

.d20-face:nth-child(5) {
  transform:
    rotateY(-288deg)
    translateZ(33.5px)
    translateY(-12.9px)
    rotateX(53deg);
}

.d20-face:nth-child(6) {
  transform:
    rotateY(360deg)
    translateZ(75px)
    translateY(54.18px)
    rotateZ(180deg)
    rotateX(-11deg);
}

.d20-face:nth-child(7) {
  transform:
    rotateY(288deg)
    translateZ(75px)
    translateY(54.18px)
    rotateZ(180deg)
    rotateX(-11deg);
}

.d20-face:nth-child(8) {
  transform:
    rotateY(216deg)
    translateZ(75px)
    translateY(54.18px)
    rotateZ(180deg)
    rotateX(-11deg);
}

.d20-face:nth-child(9) {
  transform:
    rotateY(144deg)
    translateZ(75px)
    translateY(54.18px)
    rotateZ(180deg)
    rotateX(-11deg);
}

.d20-face:nth-child(10) {
  transform:
    rotateY(72deg)
    translateZ(75px)
    translateY(54.18px)
    rotateZ(180deg)
    rotateX(-11deg);
}

.d20-face:nth-child(11) {
  transform:
    rotateY(252deg)
    translateZ(75px)
    translateY(54.18px)
    rotateX(-11deg);
}

.d20-face:nth-child(12) {
  transform:
    rotateY(324deg)
    translateZ(75px)
    translateY(54.18px)
    rotateX(-11deg);
}

.d20-face:nth-child(13) {
  transform:
    rotateY(396deg)
    translateZ(75px)
    translateY(54.18px)
    rotateX(-11deg);
}

.d20-face:nth-child(14) {
  transform:
    rotateY(468deg)
    translateZ(75px)
    translateY(54.18px)
    rotateX(-11deg);
}

.d20-face:nth-child(15) {
  transform:
    rotateY(540deg)
    translateZ(75px)
    translateY(54.18px)
    rotateX(-11deg);
}

.d20-face:nth-child(16) {
  transform:
    rotateY(-108deg)
    translateZ(33.5px)
    translateY(121.08px)
    rotateZ(180deg)
    rotateX(53deg);
}

.d20-face:nth-child(17) {
  transform:
    rotateY(-36deg)
    translateZ(33.5px)
    translateY(121.08px)
    rotateZ(180deg)
    rotateX(53deg);
}

.d20-face:nth-child(18) {
  transform:
    rotateY(36deg)
    translateZ(33.5px)
    translateY(121.08px)
    rotateZ(180deg)
    rotateX(53deg);
}

.d20-face:nth-child(19) {
  transform:
    rotateY(108deg)
    translateZ(33.5px)
    translateY(121.08px)
    rotateZ(180deg)
    rotateX(53deg);
}

.d20-face:nth-child(20) {
  transform:
    rotateY(180deg)
    translateZ(33.5px)
    translateY(121.08px)
    rotateZ(180deg)
    rotateX(53deg);
}

/* --------------------------------------------------
   Final face positions
-------------------------------------------------- */

.d20-die[data-face="1"] {
  transform: rotateX(-53deg) rotateY(0deg);
}

.d20-die[data-face="2"] {
  transform: rotateX(-53deg) rotateY(72deg);
}

.d20-die[data-face="3"] {
  transform: rotateX(-53deg) rotateY(144deg);
}

.d20-die[data-face="4"] {
  transform: rotateX(-53deg) rotateY(216deg);
}

.d20-die[data-face="5"] {
  transform: rotateX(-53deg) rotateY(288deg);
}

.d20-die[data-face="6"] {
  transform: rotateX(11deg) rotateZ(180deg) rotateY(0deg);
}

.d20-die[data-face="7"] {
  transform: rotateX(11deg) rotateZ(180deg) rotateY(72deg);
}

.d20-die[data-face="8"] {
  transform: rotateX(11deg) rotateZ(180deg) rotateY(144deg);
}

.d20-die[data-face="9"] {
  transform: rotateX(11deg) rotateZ(180deg) rotateY(216deg);
}

.d20-die[data-face="10"] {
  transform: rotateX(11deg) rotateZ(180deg) rotateY(288deg);
}

.d20-die[data-face="11"] {
  transform: rotateX(11deg) rotateY(-252deg);
}

.d20-die[data-face="12"] {
  transform: rotateX(11deg) rotateY(-324deg);
}

.d20-die[data-face="13"] {
  transform: rotateX(11deg) rotateY(-396deg);
}

.d20-die[data-face="14"] {
  transform: rotateX(11deg) rotateY(-468deg);
}

.d20-die[data-face="15"] {
  transform: rotateX(11deg) rotateY(-540deg);
}

.d20-die[data-face="16"] {
  transform: rotateX(127deg) rotateY(-72deg);
}

.d20-die[data-face="17"] {
  transform: rotateX(127deg) rotateY(-144deg);
}

.d20-die[data-face="18"] {
  transform: rotateX(127deg) rotateY(-216deg);
}

.d20-die[data-face="19"] {
  transform: rotateX(127deg) rotateY(-288deg);
}

.d20-die[data-face="20"] {
  transform: rotateX(127deg) rotateY(-360deg);
}

/* --------------------------------------------------
   Roll area
-------------------------------------------------- */

.d20-roll-area {
  position: relative;

  display: inline-block;

  margin-top: 5px;
}

/* --------------------------------------------------
   Retro Georgia Roll button
-------------------------------------------------- */

.d20-randomize {
  position: relative;

  min-width: 125px;

  padding: 10px 22px;

  border: 2px solid var(--d20-color);

  border-radius: 3px;

  background: transparent;

  color: var(--d20-color);

  font-family: var(--d20-font);

  font-size: 17px;
  font-weight: bold;

  letter-spacing: 1px;

  cursor: pointer;

  /*
    Slow idle breathing/blinking.
  */
  animation: idle-blink 3.2s ease-in-out infinite;

  transition:
    background 0.2s ease,
    color 0.2s ease,
    opacity 0.2s ease;
}

/* --------------------------------------------------
   Slow idle blinking
-------------------------------------------------- */

@keyframes idle-blink {
  0%,
  100% {
    opacity: 1;
    background: transparent;
    color: var(--d20-color);
  }

  50% {
    opacity: 0.55;
    background: rgba(138, 15, 35, 0.08);
    color: var(--d20-color);
  }
}

/* --------------------------------------------------
   Click / rolling blink
-------------------------------------------------- */

.d20-randomize.sparkling {
  animation: roll-blink 1.4s ease-in-out infinite;
}

@keyframes roll-blink {
  0%,
  100% {
    opacity: 1;
    background: var(--d20-color);
    color: #fff;
  }

  50% {
    opacity: 0.65;
    background: transparent;
    color: var(--d20-color);
  }
}

.d20-randomize:hover {
  opacity: 1;

  background: var(--d20-color);

  color: #fff;

  animation: none;
}

.d20-randomize:active {
  transform: translateY(1px);
}

/* --------------------------------------------------
   Button sparks
-------------------------------------------------- */

.d20-button-sparks {
  position: absolute;

  left: 50%;
  top: 50%;

  width: 1px;
  height: 1px;

  pointer-events: none;

  z-index: 20;
}

.d20-button-spark {
  position: absolute;

  left: 0;
  top: 0;

  width: 4px;
  height: 4px;

  border-radius: 50%;

  background: var(--d20-color);

  opacity: 0;

  animation: button-spark 650ms ease-out forwards;
}

@keyframes button-spark {
  0% {
    opacity: 1;

    transform:
      translate(-50%, -50%)
      rotate(var(--spark-angle))
      translateX(5px)
      scale(1);
  }

  100% {
    opacity: 0;

    transform:
      translate(-50%, -50%)
      rotate(var(--spark-angle))
      translateX(var(--spark-distance))
      scale(0);
  }
}