.page-about {
  --about-gap: clamp(18px, 3vw, 28px);
  display: block;
}

.page-about .about-hero {
  display: grid;
  gap: var(--about-gap);
  padding: clamp(22px, 4vw, 40px) 0 clamp(30px, 5vw, 56px);
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero__text {
  display: grid;
  gap: 16px;
  align-content: start;
}

.page-about .about-h1 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(30px, 7.6vw, 56px);
  line-height: 1.16;
  letter-spacing: 0.05em;
  color: var(--white);
}

.page-about .about-lede {
  margin: 0;
  font-size: 16px;
  line-height: 1.9;
  color: var(--muted);
  max-width: 46em;
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 4px;
}

.page-about .about-hero__figure {
  margin: 0;
  border: 1px solid var(--line);
  background: var(--panel);
  overflow: hidden;
}

.page-about .about-hero__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 14 / 9;
  object-fit: cover;
}

.page-about .about-body {
  display: grid;
  gap: 26px;
  padding: clamp(30px, 5vw, 56px) 0 clamp(40px, 6vw, 72px);
}

.page-about .about-rail {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 6px;
  scrollbar-width: thin;
}

.page-about .about-rail__title {
  display: none;
  margin: 0 0 10px;
  font-size: 12px;
  letter-spacing: 0.22em;
  color: var(--dim);
}

.page-about .about-rail__link {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 9px 14px;
  border: 1px solid var(--line);
  background: var(--panel);
  color: var(--muted);
  font-size: 14px;
  line-height: 1.2;
  text-decoration: none;
  white-space: nowrap;
  transition: color 160ms var(--ease), border-color 160ms var(--ease), background 160ms var(--ease);
}

.page-about .about-rail__link .stand-mono {
  font-size: 11px;
  color: var(--orange);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  color: var(--white);
  border-color: var(--orange);
  background: var(--panel-2);
  outline: none;
}

.page-about .about-stream {
  display: grid;
  gap: clamp(34px, 5vw, 58px);
  min-width: 0;
}

.page-about .about-section {
  scroll-margin-top: calc(var(--header-h) + 24px);
}

.page-about .about-h2 {
  margin: 0 0 14px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(21px, 4.2vw, 31px);
  line-height: 1.3;
  letter-spacing: 0.045em;
  color: var(--white);
}

.page-about p {
  margin: 0 0 14px;
  font-size: 16px;
  line-height: 1.9;
  color: var(--muted);
}

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

.page-about a {
  color: var(--cyan);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about a:hover,
.page-about a:focus-visible {
  color: var(--orange-lit);
}

.page-about .about-note {
  margin-top: 16px;
  padding: 14px 16px;
  border-left: 2px solid var(--line);
  background: var(--panel);
  font-size: 15px;
}

.page-about .about-pull {
  margin-top: 20px;
  padding: 20px 22px;
  border: 1px solid var(--line);
  border-left: 3px solid var(--orange);
  background: var(--panel);
}

.page-about .about-pull__quote {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(17px, 3.4vw, 21px);
  line-height: 1.65;
  letter-spacing: 0.02em;
  color: var(--white);
}

.page-about .about-pull__by {
  margin: 0;
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--dim);
}

.page-about .about-flow {
  display: grid;
  gap: 10px;
  margin: 18px 0 4px;
  counter-reset: none;
}

.page-about .flow-step {
  border: 1px solid var(--line);
  border-left: 2px solid var(--cyan);
  background: var(--panel);
}

.page-about .flow-step[open] {
  border-left-color: var(--orange);
  background: var(--panel-2);
}

.page-about .flow-step > summary {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 14px 16px;
  cursor: pointer;
  list-style: none;
  color: var(--white);
}

.page-about .flow-step > summary::-webkit-details-marker {
  display: none;
}

.page-about .flow-step > summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 18px;
  line-height: 1;
  color: var(--orange);
}

.page-about .flow-step[open] > summary::after {
  content: "−";
}

.page-about .flow-step > summary:focus-visible {
  outline: 2px solid var(--orange);
  outline-offset: -2px;
}

.page-about .flow-step__idx {
  font-size: 12px;
  color: var(--cyan);
  letter-spacing: 0.1em;
}

.page-about .flow-step__name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 16px;
  letter-spacing: 0.04em;
}

.page-about .flow-step__hint {
  font-size: 13px;
  color: var(--dim);
}

.page-about .flow-step__body {
  padding: 0 16px 16px 40px;
}

.page-about .flow-step__body p {
  margin: 0;
  font-size: 15px;
}

.page-about .about-roles {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 18px 0 20px;
}

.page-about .about-role-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line);
}

.page-about .about-role-list li {
  padding: 16px 18px;
  background: var(--panel);
}

.page-about .about-role-name {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 16px;
  letter-spacing: 0.05em;
  color: var(--white);
}

.page-about .about-role-list p {
  margin: 0;
  font-size: 15px;
}

.page-about .about-team-figure,
.page-about .about-timeline-figure {
  margin: 22px 0 0;
  border: 1px solid var(--line);
  background: var(--panel);
  overflow: hidden;
}

.page-about .about-team-figure img,
.page-about .about-timeline-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .about-team-figure img {
  aspect-ratio: 3 / 2;
}

.page-about .about-timeline-figure img {
  aspect-ratio: 10 / 7;
}

.page-about .about-timeline {
  list-style: none;
  margin: 20px 0 0;
  padding: 0 0 0 22px;
  border-left: 1px solid var(--line);
}

.page-about .tl-item {
  position: relative;
  padding-bottom: 18px;
}

.page-about .tl-item:last-child {
  padding-bottom: 0;
}

.page-about .tl-item::before {
  content: "";
  position: absolute;
  left: -27px;
  top: 8px;
  width: 9px;
  height: 9px;
  background: var(--night);
  border: 1px solid var(--cyan);
}

.page-about .tl-item:first-child::before {
  border-color: var(--orange);
  background: var(--orange);
}

.page-about .tl-year {
  display: block;
  font-size: 13px;
  letter-spacing: 0.16em;
  color: var(--cyan);
  margin-bottom: 4px;
}

.page-about .tl-detail {
  border: 1px solid var(--line);
  background: var(--panel);
}

.page-about .tl-detail > summary {
  padding: 11px 14px;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 15.5px;
  letter-spacing: 0.03em;
  color: var(--white);
  display: flex;
  align-items: baseline;
  gap: 10px;
}

.page-about .tl-detail > summary::-webkit-details-marker {
  display: none;
}

.page-about .tl-detail > summary::after {
  content: "展开";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--dim);
}

.page-about .tl-detail[open] > summary::after {
  content: "收起";
  color: var(--orange);
}

.page-about .tl-detail > summary:focus-visible {
  outline: 2px solid var(--orange);
  outline-offset: -2px;
}

.page-about .tl-detail p {
  margin: 0;
  padding: 0 14px 14px;
  font-size: 15px;
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 20px 0;
  background: var(--line-soft);
  border: 1px solid var(--line);
}

.page-about .about-stat {
  display: grid;
  gap: 4px;
  padding: 16px 16px 18px;
  background: var(--panel);
}

.page-about .about-stat__num {
  font-size: clamp(26px, 5.4vw, 38px);
  font-weight: 700;
  line-height: 1;
  color: var(--cyan);
  letter-spacing: 0.02em;
}

.page-about .about-stat__unit {
  font-size: 15px;
  color: var(--muted);
  margin-left: 2px;
}

.page-about .about-stat__label {
  font-size: 13px;
  line-height: 1.5;
  color: var(--muted);
}

.page-about .about-zone-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 16px 0 0;
}

.page-about .about-notes-section {
  padding-top: 24px;
  border-top: 1px solid var(--line);
}

.page-about .flag-strip {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  height: 4px;
  margin-top: 22px;
  gap: 2px;
}

.page-about .flag-strip span:nth-child(1) { background: var(--flag-blue); }
.page-about .flag-strip span:nth-child(2) { background: var(--white); }
.page-about .flag-strip span:nth-child(3) { background: var(--red); }
.page-about .flag-strip span:nth-child(4) { background: var(--green); }
.page-about .flag-strip span:nth-child(5) { background: var(--yellow); }

.page-about .about-cta {
  display: grid;
  gap: 18px;
  padding: 24px 22px;
  border: 1px solid var(--line);
  border-top: 2px solid var(--orange);
  background: var(--panel);
}

.page-about .about-cta__text p {
  margin: 0;
  font-size: 15px;
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .about-cta__actions .stand-btn {
  text-decoration: none;
}

@media (min-width: 720px) {
  .page-about .about-role-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-cta {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    padding: 28px 26px;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    align-items: end;
  }

  .page-about .about-h1 {
    letter-spacing: 0.06em;
  }
}

@media (min-width: 1000px) {
  .page-about .about-body {
    grid-template-columns: 216px minmax(0, 1fr);
    gap: 52px;
  }

  .page-about .about-rail {
    display: grid;
    gap: 2px;
    overflow: visible;
    align-self: start;
    position: sticky;
    top: calc(var(--header-h) + 18px);
  }

  .page-about .about-rail__title {
    display: block;
  }

  .page-about .about-rail__link {
    justify-content: flex-start;
    border-color: transparent;
    border-left: 2px solid var(--line);
    background: transparent;
    padding: 10px 12px;
    white-space: normal;
  }

  .page-about .about-rail__link:hover,
  .page-about .about-rail__link:focus-visible {
    border-left-color: var(--orange);
    background: var(--panel);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-rail__link,
  .page-about .flow-step,
  .page-about .tl-detail {
    transition: none;
  }
}