.page-about {
  --about-rule: rgba(40, 71, 100, .55);
  --about-rail: 168px;
  --about-glow: radial-gradient(circle at 82% 8%, rgba(56, 242, 208, .13), transparent 62%);
  background: var(--ink-950);
  color: var(--paper);
}

.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(1.4rem, 4vw, 2.4rem) 0 clamp(2.4rem, 7vw, 4.6rem);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -18%;
  right: -24%;
  width: min(820px, 108vw);
  height: min(600px, 78vw);
  background: linear-gradient(142deg, rgba(56, 242, 208, .20), rgba(255, 122, 26, .12) 54%, transparent 76%);
  clip-path: polygon(26% 0, 100% 0, 100% 100%, 0 74%);
  pointer-events: none;
}

.page-about .about-hero .crumbs {
  position: relative;
  z-index: 1;
}

.page-about .about-hero__grid {
  position: relative;
  z-index: 1;
  display: grid;
  gap: clamp(1.6rem, 4vw, 3rem);
  grid-template-columns: 1fr;
  margin-top: clamp(1.2rem, 4vw, 2.6rem);
}

.page-about .about-hero__eyebrow {
  font-size: .72rem;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--cyan);
  margin: 0 0 .8rem;
}

.page-about .about-hero__title {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(2.3rem, 7.6vw, 4.2rem);
  line-height: 1.05;
  letter-spacing: -.012em;
  margin: 0 0 1.1rem;
  color: var(--paper);
}

.page-about .about-hero__title em {
  font-style: normal;
  display: inline-block;
  color: var(--cyan);
}

.page-about .about-hero__leadtext {
  max-width: 34rem;
  color: var(--slate);
  font-size: 1rem;
  line-height: 1.85;
  margin: 0;
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: .7rem;
  margin-top: 1.6rem;
}

.page-about .about-hero__plaque {
  position: relative;
  padding: 1.3rem 1.2rem 1.5rem;
  background: linear-gradient(158deg, var(--ink-900), var(--ink-950) 72%);
  border: var(--edge);
  box-shadow: var(--shadow-soft);
  clip-path: polygon(0 0, 100% 0, 100% 92%, 0 100%);
}

.page-about .about-hero__year {
  display: block;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(4rem, 17vw, 7.6rem);
  line-height: .84;
  letter-spacing: -.035em;
  color: rgba(184, 255, 241, .10);
  -webkit-text-stroke: 1px rgba(56, 242, 208, .48);
}

.page-about .about-hero__plaquecap {
  font-size: .68rem;
  letter-spacing: .14em;
  color: var(--slate);
  margin: .7rem 0 1rem;
}

.page-about .about-hero__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: .62rem;
  font-size: .86rem;
  line-height: 1.6;
  color: var(--paper);
}

.page-about .about-hero__list li {
  display: flex;
  align-items: flex-start;
  gap: .55rem;
  padding-bottom: .62rem;
  border-bottom: 1px solid var(--about-rule);
}

.page-about .about-hero__list li:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

.page-about .about-hero__list .dot {
  margin-top: .45rem;
  flex: 0 0 auto;
}

.page-about .about-chapter {
  padding: clamp(2.2rem, 6vw, 4rem) 0;
  background: var(--ink-950);
}

.page-about .about-chapter--band {
  background: linear-gradient(180deg, var(--ink-900), var(--ink-950) 88%);
  border-top: 1px solid var(--about-rule);
  border-bottom: 1px solid var(--about-rule);
}

.page-about .chapter {
  display: grid;
  gap: clamp(1rem, 3vw, 2.2rem);
  grid-template-columns: 1fr;
}

.page-about .chapter__rail {
  display: flex;
  align-items: baseline;
  gap: .7rem;
}

.page-about .chapter__num {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(2.2rem, 8vw, 3.4rem);
  line-height: .9;
  letter-spacing: -.02em;
  color: transparent;
  -webkit-text-stroke: 1px var(--line-600);
}

.page-about .chapter__tag {
  font-size: .68rem;
  letter-spacing: .16em;
  color: var(--cyan);
  text-transform: uppercase;
}

.page-about .chapter__title {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.5rem, 4.6vw, 2.3rem);
  line-height: 1.18;
  letter-spacing: -.005em;
  color: var(--paper);
  margin: 0 0 .8rem;
}

.page-about .chapter__lead {
  font-size: 1.02rem;
  line-height: 1.7;
  color: var(--cyan-100);
  margin: 0 0 1.2rem;
  padding-left: .85rem;
  border-left: 2px solid var(--cyan);
}

.page-about .chapter__body p {
  margin: 0 0 1rem;
  font-size: .95rem;
  line-height: 1.85;
  color: var(--paper);
  max-width: 42rem;
}

.page-about .chapter__aside {
  margin-top: 1.4rem;
  padding: 1rem 1.1rem;
  background: var(--ink-900);
  border: var(--edge);
  border-left: 2px solid var(--orange);
}

.page-about .chapter__asidelabel {
  font-size: .66rem;
  letter-spacing: .14em;
  color: var(--orange-100);
  margin: 0 0 .7rem;
}

.page-about .chapter__asideList {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: .5rem;
  font-size: .88rem;
  line-height: 1.65;
  color: var(--slate);
}

.page-about .chapter__asideList li {
  padding-left: .9rem;
  position: relative;
}

.page-about .chapter__asideList li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .62rem;
  width: 5px;
  height: 5px;
  background: var(--cyan);
}

.page-about .tl {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
}

.page-about .tl::before {
  content: "";
  position: absolute;
  left: 8px;
  top: .6rem;
  bottom: .6rem;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan), rgba(56, 242, 208, .06));
}

.page-about .tl__node {
  position: relative;
  margin-bottom: .55rem;
}

.page-about .tl__node:last-child {
  margin-bottom: 0;
}

.page-about .tl__item {
  border: 1px solid transparent;
  transition: border-color .18s ease, background-color .18s ease;
}

.page-about .tl__item:hover,
.page-about .tl__item:focus-within,
.page-about .tl__item[open] {
  border-color: var(--about-rule);
  background: rgba(16, 43, 72, .38);
}

.page-about .tl__summary {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: .3rem .6rem;
  padding: .55rem .7rem .55rem 2.1rem;
  cursor: pointer;
  list-style: none;
}

.page-about .tl__summary::-webkit-details-marker {
  display: none;
}

.page-about .tl__summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 1rem;
  line-height: 1;
  color: var(--cyan);
}

.page-about .tl__item[open] .tl__summary::after {
  content: "−";
  color: var(--orange);
}

.page-about .tl__dot {
  position: absolute;
  left: 0;
  top: .82rem;
  width: 17px;
  height: 17px;
  border-radius: 50%;
  border: 1px solid var(--line-600);
  background: var(--ink-950);
  display: grid;
  place-items: center;
}

.page-about .tl__dot::after {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--cyan);
}

.page-about .tl__node--now .tl__dot {
  border-color: var(--orange);
}

.page-about .tl__node--now .tl__dot::after {
  background: var(--orange);
}

.page-about .tl__stage {
  font-size: .66rem;
  letter-spacing: .12em;
  color: var(--slate);
  flex: 0 0 auto;
}

.page-about .tl__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.06rem;
  line-height: 1.35;
  color: var(--paper);
}

.page-about .tl__body {
  padding: 0 .8rem 1rem 2.1rem;
}

.page-about .tl__body p {
  margin: 0;
  font-size: .9rem;
  line-height: 1.8;
  color: var(--slate);
  max-width: 40rem;
}

.page-about .about-figure {
  margin: clamp(1.4rem, 4vw, 2.4rem) 0 0;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  border: 1px solid var(--line-600);
  background: var(--ink-900);
}

.page-about .about-figure figcaption {
  margin-top: .6rem;
  font-size: .68rem;
  letter-spacing: .08em;
  color: var(--slate);
}

.page-about .about-figure--narrow {
  max-width: 34rem;
}

.page-about .steps4 {
  display: grid;
  gap: .85rem;
  grid-template-columns: 1fr;
  margin-top: 1.2rem;
}

.page-about .step4 {
  position: relative;
  padding: 1.05rem 1rem 1.15rem;
  background: var(--ink-900);
  border: 1px solid var(--about-rule);
  border-top: 2px solid var(--line-600);
  transition: border-color .18s ease, transform .18s ease;
}

.page-about .step4:hover,
.page-about .step4:focus-within {
  border-top-color: var(--cyan);
  border-color: var(--line-600);
  transform: translateY(-2px);
}

.page-about .step4__idx {
  display: block;
  font-size: .68rem;
  letter-spacing: .18em;
  color: var(--cyan);
  margin-bottom: .5rem;
}

.page-about .step4__title {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 1.18rem;
  line-height: 1.3;
  color: var(--paper);
  margin: 0 0 .55rem;
}

.page-about .step4__what {
  font-size: .87rem;
  line-height: 1.75;
  color: var(--paper);
  margin: 0 0 .7rem;
}

.page-about .step4__fix {
  display: flex;
  align-items: flex-start;
  gap: .5rem;
  margin: 0;
  padding-top: .7rem;
  border-top: 1px dashed var(--about-rule);
  font-size: .8rem;
  line-height: 1.65;
  color: var(--slate);
}

.page-about .step4__fix .dot {
  margin-top: .42rem;
  flex: 0 0 auto;
}

.page-about .principles {
  display: grid;
  gap: 1rem;
  grid-template-columns: 1fr;
  margin-top: 1.2rem;
}

.page-about .principle {
  padding: 1rem 1.05rem 1.15rem;
  border: 1px solid var(--about-rule);
  background: rgba(16, 43, 72, .42);
  border-left: 2px solid var(--cyan);
}

.page-about .principle__num {
  display: block;
  font-size: .66rem;
  letter-spacing: .16em;
  color: var(--cyan);
  margin-bottom: .5rem;
}

.page-about .principle__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.1rem;
  line-height: 1.3;
  color: var(--paper);
  margin: 0 0 .5rem;
}

.page-about .principle p {
  margin: 0;
  font-size: .87rem;
  line-height: 1.8;
  color: var(--slate);
}

.page-about .rhythm {
  display: grid;
  gap: 1.2rem;
  grid-template-columns: 1fr;
}

.page-about .rhythm__text p {
  margin: 0 0 1rem;
  font-size: .95rem;
  line-height: 1.85;
  color: var(--paper);
  max-width: 42rem;
}

.page-about .rhythm__tags {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem;
  align-content: flex-start;
}

.page-about .about-chapter--support {
  background:
    var(--about-glow),
    linear-gradient(180deg, var(--ink-900), var(--ink-950));
  border-top: 1px solid var(--about-rule);
}

.page-about .support {
  display: grid;
  gap: 1.1rem;
  grid-template-columns: 1fr;
}

.page-about .support__head .chapter__num {
  display: block;
  margin-bottom: .6rem;
}

.page-about .support__head .chapter__title {
  margin-bottom: 0;
}

.page-about .support__body p {
  margin: 0 0 1rem;
  font-size: .94rem;
  line-height: 1.85;
  color: var(--paper);
  max-width: 42rem;
}

.page-about .support__actions {
  display: flex;
  flex-wrap: wrap;
  gap: .7rem;
  margin-top: 1.2rem;
}

.page-about .about-chapter--next {
  padding-bottom: clamp(2.6rem, 7vw, 5rem);
}

.page-about .next__head .chapter__lead {
  margin-bottom: 1.4rem;
}

.page-about .next__grid {
  display: grid;
  gap: .9rem;
  grid-template-columns: 1fr;
}

.page-about .next__card {
  display: block;
  padding: 1.1rem 1.05rem 1.25rem;
  background: var(--ink-900);
  border: 1px solid var(--about-rule);
  text-decoration: none;
  color: inherit;
  transition: border-color .18s ease, background-color .18s ease, transform .18s ease;
}

.page-about .next__card:hover,
.page-about .next__card:focus-visible {
  border-color: var(--cyan);
  background: var(--ink-800);
  transform: translateY(-2px);
}

.page-about .next__idx {
  display: block;
  font-size: .64rem;
  letter-spacing: .18em;
  color: var(--orange);
  margin-bottom: .6rem;
}

.page-about .next__title {
  display: block;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 1.14rem;
  line-height: 1.3;
  color: var(--paper);
  margin-bottom: .45rem;
}

.page-about .next__desc {
  display: block;
  font-size: .85rem;
  line-height: 1.7;
  color: var(--slate);
}

.page-about .next__foot {
  margin: 1.4rem 0 0;
  font-size: .86rem;
  line-height: 1.7;
  color: var(--slate);
}

.page-about .next__foot a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(56, 242, 208, .4);
}

.page-about .next__foot a:hover,
.page-about .next__foot a:focus-visible {
  border-bottom-color: var(--cyan);
  color: var(--cyan-100);
}

@media (min-width: 720px) {
  .page-about .about-hero__grid {
    grid-template-columns: 1.15fr .85fr;
    align-items: start;
  }

  .page-about .about-hero__plaque {
    margin-top: 1.6rem;
  }

  .page-about .principles {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .next__grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .page-about .chapter {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .chapter__rail {
    flex-direction: column;
    align-items: flex-start;
    gap: .55rem;
    padding-top: .35rem;
    position: sticky;
    top: 5.5rem;
  }

  .page-about .chapter__num {
    font-size: 3.6rem;
  }

  .page-about .support {
    grid-template-columns: minmax(0, .78fr) minmax(0, 1.22fr);
    gap: 2.4rem;
    align-items: start;
  }

  .page-about .rhythm {
    grid-template-columns: minmax(0, 1.5fr) minmax(0, .5fr);
    gap: 2rem;
  }

  .page-about .steps4 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1rem;
  }

  .page-about .step4:nth-child(even) {
    margin-top: 1.6rem;
  }
}

@media (min-width: 1080px) {
  .page-about .steps4 {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .step4:nth-child(2) {
    margin-top: 1.1rem;
  }

  .page-about .step4:nth-child(3) {
    margin-top: .4rem;
  }

  .page-about .step4:nth-child(4) {
    margin-top: 1.9rem;
  }

  .page-about .principles {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1.2rem 1.6rem;
  }

  .page-about .tl__summary {
    padding-left: 2.6rem;
  }

  .page-about .tl__body {
    padding-left: 2.6rem;
  }

  .page-about .tl::before {
    left: 8px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .step4,
  .page-about .next__card,
  .page-about .tl__item {
    transition: none;
  }

  .page-about .step4:hover,
  .page-about .step4:focus-within,
  .page-about .next__card:hover,
  .page-about .next__card:focus-visible {
    transform: none;
  }
}
<<<END>>>