.page-about {
  display: block;
  background: var(--ink);
  color: var(--white);
  font-family: var(--font-body);
  --about-gap: clamp(1.5rem, 4vw, 2.75rem);
  --about-tip-bg: #16283C;
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumb {
  padding-top: clamp(1rem, 3vw, 1.75rem);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  color: var(--mist);
}
.page-about .breadcrumb a {
  color: var(--mist);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.2s ease-out, border-color 0.2s ease-out;
}
.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible {
  color: var(--gold-hi);
  border-bottom-color: var(--gold-hi);
}
.page-about .breadcrumb__sep {
  margin: 0 0.5rem;
  color: var(--line);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  padding: clamp(1.75rem, 5vw, 3.25rem) 0 clamp(2.5rem, 6vw, 5rem);
}
.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: -12% -6% auto -6%;
  height: 140%;
  z-index: -1;
  pointer-events: none;
  background:
    radial-gradient(46% 58% at 80% 6%, rgba(201, 162, 74, 0.17), transparent 62%),
    radial-gradient(44% 56% at 6% 74%, rgba(79, 179, 166, 0.11), transparent 66%),
    linear-gradient(to right, rgba(27, 43, 61, 0.9) 1px, transparent 1px) 0 0 / 76px 76px,
    linear-gradient(to bottom, rgba(27, 43, 61, 0.9) 1px, transparent 1px) 0 0 / 76px 76px;
}
.page-about .about-hero__inner {
  display: grid;
  gap: clamp(2rem, 5vw, 3.5rem);
  align-items: start;
}
.page-about .about-hero__kicker {
  color: var(--gold);
  margin: 0 0 0.5rem;
}
.page-about .about-hero__title {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(2.2rem, 6.2vw, 4.4rem);
  line-height: 1.06;
  letter-spacing: -0.02em;
  margin: 0 0 1.15rem;
  color: var(--white);
}
.page-about .about-hero__intro {
  margin: 0;
  max-width: 46ch;
  font-size: clamp(1rem, 1.2vw, 1.0625rem);
  line-height: 1.85;
  color: var(--mist);
}
.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1rem;
  margin-top: 1.75rem;
}
.page-about .about-hero__figure {
  margin: 0;
  padding: 0.5rem;
  background: var(--hold);
  border: 1px solid var(--gold);
  box-shadow: var(--shadow-hard);
}
.page-about .about-hero__figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}
.page-about .about-caption {
  display: block;
  margin-top: 0.75rem;
  padding: 0 0.25rem;
  font-size: 0.8rem;
  line-height: 1.6;
  color: var(--mist);
}

.page-about .about-hero__stats {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.15rem 1.25rem;
  margin: clamp(2rem, 5vw, 3.25rem) 0 0;
  padding: clamp(1.25rem, 3vw, 1.75rem) 0 0;
  border-top: 1px solid var(--grid);
}
.page-about .about-stat {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  padding-left: 0.85rem;
  border-left: 2px solid var(--gold);
}
.page-about .about-stat__num {
  font-family: var(--font-mono);
  font-size: clamp(1.3rem, 3vw, 1.85rem);
  letter-spacing: 0.02em;
  color: var(--gold-hi);
}
.page-about .about-stat__label {
  font-size: 0.8rem;
  letter-spacing: 0.05em;
  color: var(--mist);
}

/* ---------- 章节通用 ---------- */
.page-about .section {
  padding-block: clamp(3rem, 8vw, 6rem);
}
.page-about .section-head {
  margin: 0 0 clamp(2rem, 5vw, 3rem);
}
.page-about .section-number {
  color: var(--gold);
  margin: 0 0 0.75rem;
}
.page-about .section-head h2 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.75rem, 3.4vw, 2.7rem);
  line-height: 1.18;
  letter-spacing: -0.015em;
  margin: 0 0 0.85rem;
  color: var(--white);
}
.page-about .section-head > p:last-child {
  margin: 0;
  max-width: 62ch;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--mist);
}

/* ---------- 01 我们在做一件什么事 ---------- */
.page-about .about-what__list {
  display: grid;
  border-top: 1px solid var(--grid);
}
.page-about .about-what__row {
  display: grid;
  gap: 0.6rem;
  padding: clamp(1.5rem, 4vw, 2.25rem) 0;
  border-bottom: 1px solid var(--grid);
}
.page-about .about-what__id {
  color: var(--line);
  transition: color 0.25s ease-out;
}
.page-about .about-what__row:hover .about-what__id,
.page-about .about-what__row:focus-within .about-what__id {
  color: var(--gold);
}
.page-about .about-what__row h3 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.12rem, 2vw, 1.4rem);
  line-height: 1.4;
  margin: 0;
  color: var(--white);
}
.page-about .about-what__body p {
  margin: 0 0 0.75rem;
  max-width: 58ch;
  font-size: 0.97rem;
  line-height: 1.85;
  color: var(--mist);
}
.page-about .about-what__link {
  display: inline-block;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--gold-hi);
  text-decoration: none;
  border-bottom: 1px solid rgba(232, 203, 132, 0.4);
  padding-bottom: 0.1rem;
  transition: border-color 0.2s ease-out, color 0.2s ease-out;
}
.page-about .about-what__link:hover,
.page-about .about-what__link:focus-visible {
  color: var(--white);
  border-bottom-color: var(--white);
}

/* ---------- 02 版本时间线 ---------- */
.page-about .about-timeline {
  background: linear-gradient(180deg, var(--ink) 0%, var(--hold) 26%, var(--hold) 82%, var(--ink) 100%);
  border-top: 1px solid var(--grid);
  border-bottom: 1px solid var(--grid);
}
.page-about .about-timeline__plate {
  margin: 0 0 clamp(1.75rem, 4vw, 2.75rem);
  border: 1px solid var(--line);
  background: var(--ink);
  overflow: hidden;
}
.page-about .about-timeline__plate img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 10;
  object-fit: cover;
  opacity: 0.72;
}

.page-about .about-tl__list {
  list-style: none;
  margin: 0;
  padding: 0;
}
.page-about .about-tl__item {
  position: relative;
  padding-left: 1.6rem;
  padding-bottom: clamp(1.75rem, 4vw, 2.5rem);
  display: grid;
  gap: 0.5rem;
  grid-template-columns: minmax(0, 1fr);
}
.page-about .about-tl__item::before {
  content: "";
  position: absolute;
  left: 0.3rem;
  top: 0.55rem;
  bottom: 0;
  width: 1px;
  background: linear-gradient(to bottom, var(--gold), rgba(201, 162, 74, 0.1));
}
.page-about .about-tl__item::after {
  content: "";
  position: absolute;
  left: 0;
  top: 0.32rem;
  width: 0.64rem;
  height: 0.64rem;
  background: var(--ink);
  border: 1px solid var(--gold);
  transform: rotate(45deg);
}
.page-about .about-tl__item:last-child {
  padding-bottom: 0;
}
.page-about .about-tl__item:last-child::before {
  bottom: auto;
  height: 2.4rem;
  background: linear-gradient(to bottom, var(--gold), transparent);
}

.page-about .about-tl__rail {
  display: flex;
  align-items: baseline;
  gap: 0.85rem;
}
.page-about .about-tl__year {
  color: var(--mist);
  letter-spacing: 0.14em;
}
.page-about .about-tl__ver {
  position: relative;
  color: var(--gold-hi);
  font-size: 1.05rem;
  cursor: help;
  outline-offset: 4px;
}
.page-about .about-tl__ver:focus-visible {
  outline: 1px solid var(--gold-hi);
}
.page-about .about-tl__hint {
  position: absolute;
  left: 0;
  top: calc(100% + 0.5rem);
  width: max-content;
  max-width: min(15rem, 70vw);
  padding: 0.5rem 0.7rem;
  background: var(--about-tip-bg);
  border: 1px solid var(--gold);
  color: var(--white);
  font-family: var(--font-body);
  font-size: 0.78rem;
  letter-spacing: 0;
  line-height: 1.55;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-4px);
  transition: opacity 0.2s ease-out, transform 0.2s ease-out, visibility 0.2s;
  z-index: 6;
}
.page-about .about-tl__ver:hover .about-tl__hint,
.page-about .about-tl__ver:focus-visible .about-tl__hint {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.page-about .about-tl__body {
  margin: 0.85rem 0 0;
  border-top: 1px solid var(--grid);
  padding-top: 0.85rem;
}
.page-about .about-tl__body summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  align-items: baseline;
  gap: 0.7rem;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.1rem, 2.1vw, 1.45rem);
  line-height: 1.4;
  color: var(--white);
  transition: color 0.2s ease-out;
}
.page-about .about-tl__body summary::-webkit-details-marker {
  display: none;
}
.page-about .about-tl__body summary::before {
  content: "+";
  flex: none;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  line-height: 1.7;
  color: var(--gold);
}
.page-about .about-tl__body[open] summary::before {
  content: "—";
}
.page-about .about-tl__body summary:hover,
.page-about .about-tl__body summary:focus-visible {
  color: var(--gold-hi);
}
.page-about .about-tl__body p {
  margin: 0.85rem 0 0;
  max-width: 64ch;
  font-size: 0.97rem;
  line-height: 1.85;
  color: var(--mist);
}

/* ---------- 03 团队 ---------- */
.page-about .about-team__wrap {
  display: grid;
  gap: var(--about-gap);
}
.page-about .about-team__main h2 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.75rem, 3.4vw, 2.7rem);
  line-height: 1.18;
  letter-spacing: -0.015em;
  margin: 0 0 0.85rem;
  color: var(--white);
}
.page-about .about-team__lede {
  margin: 0 0 0.5rem;
  max-width: 60ch;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--mist);
}
.page-about .about-team__roles {
  margin: 0;
  border-bottom: 1px solid var(--grid);
}
.page-about .about-role {
  display: grid;
  gap: 0.4rem;
  padding: clamp(1rem, 2.5vw, 1.4rem) 0;
  border-top: 1px solid var(--grid);
}
.page-about .about-role dt {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  letter-spacing: 0.06em;
  color: var(--gold-hi);
}
.page-about .about-role dd {
  margin: 0;
  font-size: 0.95rem;
  line-height: 1.8;
  color: var(--mist);
}
.page-about .about-team__aside {
  align-self: start;
}
.page-about .about-team__figure {
  margin: 0;
  padding: 0.5rem;
  background: var(--hold);
  border: 1px solid var(--line);
  box-shadow: var(--shadow-soft);
}
.page-about .about-team__figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

/* ---------- 04 协作生态 ---------- */
.page-about .about-eco {
  background: var(--hold);
  border-top: 1px solid var(--grid);
  border-bottom: 1px solid var(--grid);
}
.page-about .about-eco__grid {
  display: grid;
  gap: 1rem;
}
.page-about .about-eco__card {
  position: relative;
  padding: clamp(1.25rem, 3vw, 1.75rem);
  background: var(--ink);
  border: 1px solid var(--line);
  border-left: 3px solid var(--gold);
  box-shadow: var(--shadow-soft);
}
.page-about .about-eco__tag {
  display: inline-block;
  margin-bottom: 0.85rem;
  padding: 0.2rem 0.6rem;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  color: var(--gold-hi);
  border: 1px solid var(--line);
}
.page-about .about-eco__card h3 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.05rem, 1.7vw, 1.28rem);
  line-height: 1.4;
  margin: 0 0 0.6rem;
  color: var(--white);
}
.page-about .about-eco__card p {
  margin: 0;
  font-size: 0.94rem;
  line-height: 1.8;
  color: var(--mist);
}
.page-about .about-eco__card--honor {
  border-left-color: var(--teal);
  background: linear-gradient(160deg, #12283A 0%, var(--ink) 70%);
}
.page-about .about-eco__card--honor .about-eco__tag {
  color: var(--teal);
}

/* ---------- 05 长期承诺 ---------- */
.page-about .about-promise__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: clamp(1.5rem, 4vw, 2.5rem);
}
.page-about .about-promise__item {
  position: relative;
  padding-left: 1.15rem;
  border-left: 1px solid var(--line);
}
.page-about .about-promise__idx {
  display: block;
  color: var(--gold);
  margin-bottom: 0.6rem;
}
.page-about .about-promise__item h3 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.08rem, 1.9vw, 1.35rem);
  line-height: 1.42;
  margin: 0 0 0.6rem;
  color: var(--white);
}
.page-about .about-promise__item p {
  margin: 0;
  max-width: 62ch;
  font-size: 0.95rem;
  line-height: 1.85;
  color: var(--mist);
}

/* ---------- 结尾入口 ---------- */
.page-about .about-next {
  padding-block: clamp(2.5rem, 6vw, 4.5rem) clamp(3.5rem, 9vw, 6.5rem);
  background: linear-gradient(180deg, var(--ink) 0%, #0E1B29 100%);
  border-top: 1px solid var(--grid);
}
.page-about .about-next__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.5rem, 3vw, 2.2rem);
  line-height: 1.22;
  letter-spacing: -0.015em;
  margin: 0 0 clamp(1.5rem, 4vw, 2.25rem);
  color: var(--white);
}
.page-about .about-next__grid {
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}
.page-about .about-next__card {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  padding: clamp(1.25rem, 3vw, 1.75rem);
  background: var(--ink);
  text-decoration: none;
  transition: background 0.25s ease-out;
}
.page-about .about-next__card:hover,
.page-about .about-next__card:focus-visible {
  background: var(--hold);
}
.page-about .about-next__idx {
  color: var(--line);
  transition: color 0.25s ease-out;
}
.page-about .about-next__card:hover .about-next__idx,
.page-about .about-next__card:focus-visible .about-next__idx {
  color: var(--amber);
}
.page-about .about-next__card strong {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.02rem, 1.6vw, 1.2rem);
  line-height: 1.4;
  color: var(--white);
}
.page-about .about-next__desc {
  font-size: 0.9rem;
  line-height: 1.75;
  color: var(--mist);
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .about-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .about-eco__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .about-next__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .about-role {
    grid-template-columns: 9.5rem minmax(0, 1fr);
    gap: 1.5rem;
    align-items: baseline;
  }
  .page-about .about-what__row {
    grid-template-columns: 4.5rem minmax(0, 1fr) minmax(0, 1.4fr);
    column-gap: 1.75rem;
    align-items: baseline;
  }
  .page-about .about-what__id {
    grid-row: span 2;
  }
}

@media (min-width: 960px) {
  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: clamp(2rem, 4vw, 4.5rem);
  }
  .page-about .about-what__head {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    column-gap: clamp(2rem, 5vw, 4rem);
    align-items: end;
  }
  .page-about .about-what__head .section-number {
    grid-column: 1 / -1;
  }
  .page-about .about-what__head h2 {
    margin-bottom: 0;
  }
  .page-about .about-team__wrap {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 0.72fr);
    gap: clamp(2rem, 5vw, 4rem);
  }
  .page-about .about-promise__list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: clamp(1.75rem, 4vw, 3rem) clamp(2rem, 5vw, 3.5rem);
  }
  .page-about .about-next__grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .about-tl__item {
    grid-template-columns: 6.5rem minmax(0, 1fr);
    column-gap: clamp(1.5rem, 3vw, 2.75rem);
    padding-left: 1.9rem;
    padding-bottom: clamp(2.5rem, 5vw, 4rem);
  }
  .page-about .about-tl__rail {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.3rem;
  }
  .page-about .about-tl__body {
    margin-top: 0;
    border-top: 0;
    padding-top: 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-tl__hint,
  .page-about .about-what__id,
  .page-about .about-next__card,
  .page-about .about-next__idx,
  .page-about .about-what__link,
  .page-about .breadcrumb a {
    transition: none;
  }
  .page-about .about-tl__hint {
    transform: none;
  }
}
</main>