@font-face {
  font-family: "Learn Serif";
  src: url("fonts/learn-serif-regular.woff2") format("woff2");
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}

@font-face {
  font-family: "Learn Serif";
  src: url("fonts/learn-serif-bold.woff2") format("woff2");
  font-weight: 700;
  font-style: normal;
  font-display: swap;
}

:root {
  --page: #e6e7ea;
  --ground: #f4f4f5;
  --spot: #ffffff;
  --ink: #17181b;
  --ink-2: #5f6368;
  --accent: #0e7c73;
  --hair: color-mix(in srgb, var(--ink) 20%, transparent);
  --serif: "Learn Serif", Charter, "Iowan Old Style", Georgia, serif;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root {
    --page: #0d0e11;
    --ground: #121316;
    --spot: #17181c;
    --ink: #ebeae6;
    --ink-2: #a6aab2;
    --accent: #63d3c4;
    color-scheme: dark;
  }
}

html {
  background: var(--page);
}

body {
  margin: 0;
  color: var(--ink);
  background: radial-gradient(
    ellipse 60% 70% at 62% 60%,
    var(--spot) 0%,
    var(--ground) 58%,
    var(--page) 100%
  );
}

main {
  --say: clamp(1.75rem, 3.2vw, 3.25rem);
  box-sizing: border-box;
  display: grid;
  grid-template-columns: calc(10.6 * var(--say)) 1fr;
  grid-template-rows: auto auto auto 1fr auto;
  grid-template-areas:
    "brand draw"
    "voice draw"
    "say draw"
    "about draw"
    "about marks";
  column-gap: 4vw;
  min-height: 100svh;
  max-width: calc(1600px + 10vw);
  margin: 0 auto;
  padding: clamp(24px, 4.5vw, 64px) 5vw;
}

.brand {
  grid-area: brand;
  margin: 0 0 clamp(24px, 3vw, 48px);
  font: 700 17px / 1.25 var(--serif);
  letter-spacing: 0.01em;
}

.voice {
  grid-area: voice;
  display: grid;
  gap: 10px;
  color: var(--ink-2);
  font: 15px / 21px var(--sans);
}

.you,
.tutor {
  display: grid;
  grid-template-columns: auto auto 1fr;
  align-items: start;
  column-gap: 10px;
  opacity: 0;
}

.bars {
  display: flex;
  align-items: center;
  gap: 3px;
  height: 1lh;
}

.bars i {
  width: 3px;
  height: 14px;
  border-radius: 1px;
  background: currentColor;
  transform: scaleY(0.22);
}

.you .bars {
  opacity: 0.55;
}

.tutor .bars {
  color: var(--accent);
}

.talking .bars i {
  animation: talk 0.8s ease-in-out infinite;
}

.talking .bars i:nth-child(2) {
  animation-delay: -0.3s;
}

.talking .bars i:nth-child(3) {
  animation-delay: -0.55s;
}

.talking .bars i:nth-child(4) {
  animation-delay: -0.15s;
}

@keyframes talk {
  0%,
  100% {
    transform: scaleY(0.25);
  }
  50% {
    transform: scaleY(1);
  }
}

.who {
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.asked {
  grid-area: 1 / 3;
}

.sentence {
  grid-area: say;
  margin: 16px 0 24px;
  font: 400 var(--say) / 1.25 var(--serif);
  letter-spacing: -0.003em;
  text-wrap: balance;
}

.sentence span,
.asked span {
  opacity: 0;
  transition: opacity 250ms ease;
}

.sentence span.said,
.asked span.said {
  opacity: 1;
}

.still .sentence span,
.still .asked span {
  transition: none;
}

.still .bars i {
  animation: none;
}

.still .talking .bars i {
  transform: scaleY(0.6);
}

.still .talking .bars i:nth-child(2) {
  transform: scaleY(0.95);
}

.still .talking .bars i:nth-child(4) {
  transform: scaleY(0.75);
}

.drawing {
  grid-area: draw;
  display: block;
  width: 100%;
  height: 100%;
  min-height: 140px;
  contain: size;
}

.about {
  grid-area: about;
  align-self: end;
  max-width: 18em;
  margin: 0;
  color: var(--ink-2);
  font: 15px / 1.5 var(--sans);
}

.marks {
  grid-area: marks;
  justify-self: end;
  display: flex;
  gap: 10px;
  margin-top: 16px;
}

.mark {
  width: 28px;
  height: 22px;
  padding: 0;
  border: 0;
  border-radius: 2px;
  cursor: pointer;
  background:
    linear-gradient(var(--accent), var(--accent)) left center / calc(var(--p, 0) * 100%) 2px
      no-repeat,
    linear-gradient(var(--hair), var(--hair)) center / 100% 2px no-repeat;
}

.mark:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.construct,
.result {
  fill: none;
  vector-effect: non-scaling-stroke;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.construct {
  stroke: var(--ink);
  stroke-opacity: 0.3;
  stroke-width: 1.25;
}

.result {
  stroke: var(--accent);
  stroke-width: 2.25;
}

.dash {
  stroke-dasharray: 3 4;
}

.point,
.lit {
  fill: var(--accent);
}

.faint {
  fill: var(--ink);
  fill-opacity: 0.06;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

@media (width < 700px) {
  body {
    background: radial-gradient(
      ellipse 80% 60% at 50% 55%,
      var(--spot) 0%,
      var(--ground) 58%,
      var(--page) 100%
    );
  }

  main {
    grid-template-columns: 100%;
    grid-template-rows: auto auto auto 1fr auto auto;
    grid-template-areas: "brand" "voice" "say" "draw" "about" "marks";
    padding: 20px;
  }

  .brand {
    margin-bottom: 28px;
  }

  .you {
    min-height: 2lh;
    align-content: end;
  }

  .sentence {
    min-height: 5em;
    margin-bottom: 20px;
    font-size: 1.625rem;
  }

  .about {
    max-width: none;
    margin-top: 20px;
  }

  .marks {
    justify-self: start;
    margin-top: 12px;
  }
}