:root {
  --color: hsl(0 0% 100% / 0.1);
  --underline-width: 1lh;
  --underline-block-width: 200vmax;
  --underline-color: hsl(0 0% 50% / 0.15);
  --underline-color-hover: hsl(180 100% 50% / 1);
  --underline-transition: 5s;
  --finish-fill: hsl(0 0% 100%);
  --accent: hsl(0 0% 100%);
  --fill: hsl(0 0% 50%);
}

/* 

************
DESCRIBTION 
****************
ptr = Full container big text
ptw = small section small text */

.ptr-container p {
  /* resize: both; */
  max-width: 70vw;
  overflow: hidden;
  padding: 10ch;
  margin: 0;
}

.ptr-container p > span {
  outline-color: hsl(10 80% 50%);
  outline-offset: 1ch;
  font-size: clamp(3rem, 4vw + 1rem, 10rem);
  color: var(--color);
  text-decoration: none;
  background-image:
		/* First one is the highlight */ linear-gradient(
      90deg,
      transparent calc(100% - 8ch),
      var(--accent) calc(100% - 8ch)
    ),
    linear-gradient(90deg, var(--fill), var(--fill)),
    linear-gradient(90deg, var(--underline-color), var(--underline-color));
  background-size: var(--underline-block-width) var(--underline-width),
    var(--underline-block-width) var(--underline-width),
    100% var(--underline-width);
  background-repeat: no-repeat;
  background-position-x: 0;
  background-position-y: 100%;
  background-clip: text;
  color: var(--finish-fill);
}

.ptr-container {
  position: sticky;
  top: 0;
  height: 100vh;
  width: 100vw;
  display: grid;
  place-items: center;
}

.ptr-wrapper {
  height: 200vh;
}

.ptw-container p {
  /* resize: both; */
  max-width: 100%;
  overflow: hidden;
  /* padding: 10ch; */
  margin: 0;
}

.ptw-container p > span {
  outline-color: hsl(10 80% 50%);
  outline-offset: 1ch;
  font-size: clamp(1.88rem, 2vw + 1rem, 10rem);
  color: var(--color);
  text-decoration: none;
  background-image:
		/* First one is the highlight */ linear-gradient(
      90deg,
      transparent calc(100% - 8ch),
      var(--accent) calc(100% - 8ch)
    ),
    linear-gradient(90deg, var(--fill), var(--fill)),
    linear-gradient(90deg, var(--underline-color), var(--underline-color));
  background-size: var(--underline-block-width) var(--underline-width),
    var(--underline-block-width) var(--underline-width),
    100% var(--underline-width);
  background-repeat: no-repeat;
  background-position-x: 0;
  background-position-y: 100%;
  background-clip: text;
  color: var(--finish-fill);
}

.ptw-container {
  position: sticky;
  top:33%;
  height: 33vh;
  width: 100vw;
  display: grid;
  place-items: center;
}

.ptw-wrapper {
  height: 66vh;
}

@media screen and (max-width: 768px) {
  .ptr-container p {
    max-width: 100vw;
    font-size: 1.33rem;
    padding: 0;
  }
  .ptw-container p {
    max-width: 100vw;
    font-size: 1.33rem;
    padding: 0;
  }
}

@supports (animation-timeline: scroll()) {
  @media (prefers-reduced-motion: no-preference) {
    .ptr-wrapper {
      view-timeline-name: --section;
    }

    .ptw-wrapper {
      view-timeline-name: --section;
    }

    .ptr-container p > span {
      background-position-x: calc(var(--underline-block-width) * -1),
        calc(var(--underline-block-width) * -1), 0;
      color: transparent;
      animation-name: fill-up, color-in;
      animation-fill-mode: both;
      animation-timing-function: linear;
      animation-timeline: --section;
      animation-range: entry 100% cover 50%, cover 50% exit 0%;
    }
    .ptw-container p > span {
      background-position-x: calc(var(--underline-block-width) * -1),
        calc(var(--underline-block-width) * -1), 0;
      color: transparent;
      animation-name: fill-up, color-in;
      animation-fill-mode: both;
      animation-timing-function: linear;
      animation-timeline: --section;
      animation-range: entry 100% cover 50%, cover 50% exit 0%;
    }

    @keyframes fill-up {
      to {
        background-position-x: 0, 0, 0;
      }
    }

    @keyframes color-in {
      to {
        color: var(--finish-fill);
      }
    }
  }
}