.page-about {
  --about-rail-w: 168px;
  --about-line-thick: 3px;
  --about-ease: cubic-bezier(.2, .7, .3, 1);
  background: var(--ink);
  color: var(--paper);
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumbs {
  padding-top: clamp(96px, 14vw, 140px);
}

.page-about .crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 12px;
  letter-spacing: .08em;
}

.page-about .crumb {
  color: var(--grey);
}

.page-about .crumb + .crumb::before {
  content: "/";
  margin-right: 8px;
  color: var(--line-strong);
}

.page-about .crumb a {
  color: var(--grey);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .18s var(--about-ease), border-color .18s var(--about-ease);
}

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

.page-about .crumb[aria-current="page"] {
  color: var(--cyan);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(120% 90% at 12% 8%, rgba(47, 240, 190, .13), transparent 58%),
    radial-gradient(90% 70% at 92% 6%, rgba(44, 107, 255, .18), transparent 62%),
    linear-gradient(180deg, var(--ink) 0%, var(--green) 100%);
  padding-bottom: clamp(56px, 9vw, 104px);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--line-strong), transparent);
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(32px, 6vw, 56px);
  margin-top: clamp(28px, 5vw, 48px);
}

.page-about .about-hero__title {
  margin: 14px 0 0;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(34px, 7.6vw, 76px);
  line-height: 1.02;
  letter-spacing: -.015em;
  color: var(--paper);
  text-wrap: balance;
}

.page-about .about-br {
  display: none;
}

.page-about .about-hero__lede {
  margin: 22px 0 0;
  max-width: 60ch;
  color: rgba(244, 247, 245, .82);
  font-size: 17px;
  line-height: 1.7;
}

.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  padding: 0;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .hero-stat {
  padding: 18px 16px;
  background: rgba(6, 18, 15, .78);
}

.page-about .hero-stat__num {
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin: 8px 0 0;
  font-family: var(--font-num);
  font-size: clamp(30px, 6vw, 46px);
  font-weight: 700;
  line-height: 1;
  color: var(--cyan);
}

.page-about .hero-stat__unit {
  font-family: var(--font-body);
  font-size: 13px;
  font-weight: 500;
  color: var(--grey);
}

/* ---------- 年份时间轴 ---------- */
.page-about .about-timeline {
  position: relative;
  padding: clamp(52px, 9vw, 104px) 0;
  background:
    linear-gradient(180deg, rgba(11, 59, 46, .96), rgba(6, 18, 15, .98));
}

.page-about .about-timeline__grid {
  display: grid;
  gap: 28px;
}

.page-about .about-rail {
  position: sticky;
  top: 96px;
  align-self: start;
  z-index: 2;
}

.page-about .about-rail__title {
  margin: 0 0 12px;
  color: var(--grey);
}

.page-about .about-rail__list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 4px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
  background: rgba(6, 18, 15, .72);
  border: 1px solid var(--line);
  border-radius: 999px;
}

.page-about .about-rail__list::-webkit-scrollbar {
  display: none;
}

.page-about .about-rail__item {
  flex: 0 0 auto;
}

.page-about .about-rail__link {
  display: flex;
  align-items: baseline;
  gap: 6px;
  padding: 8px 14px;
  border-radius: 999px;
  text-decoration: none;
  white-space: nowrap;
  transition: background .2s var(--about-ease), color .2s var(--about-ease);
}

.page-about .about-rail__year {
  font-family: var(--font-num);
  font-size: 14px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .about-rail__tag {
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--grey);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  background: rgba(47, 240, 190, .14);
}

.page-about .about-rail__link:hover .about-rail__year,
.page-about .about-rail__link:focus-visible .about-rail__year,
.page-about .about-rail__link:hover .about-rail__tag,
.page-about .about-rail__link:focus-visible .about-rail__tag {
  color: var(--cyan);
}

.page-about .about-years {
  display: grid;
  gap: 20px;
}

.page-about .year-block {
  position: relative;
  padding: 22px 20px 24px;
  background: rgba(6, 18, 15, .6);
  border: 1px solid var(--line);
  border-left: var(--about-line-thick) solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: border-color .25s var(--about-ease), background .25s var(--about-ease), transform .25s var(--about-ease);
  scroll-margin-top: 108px;
}

.page-about .year-block:target,
.page-about .year-block:hover {
  border-left-color: var(--cyan);
  background: rgba(6, 18, 15, .84);
}

.page-about .year-block:target {
  transform: translateX(2px);
}

.page-about .year-block:target .year-block__year {
  color: var(--cyan);
}

.page-about .year-block__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 12px;
}

.page-about .year-block__year {
  font-family: var(--font-num);
  font-size: clamp(30px, 7vw, 52px);
  font-weight: 700;
  line-height: 1;
  color: var(--yellow);
  transition: color .25s var(--about-ease);
}

.page-about .year-block__title {
  margin: 0;
  font-family: var(--font-head);
  font-size: clamp(19px, 3.4vw, 26px);
  font-weight: 700;
  letter-spacing: -.01em;
  color: var(--paper);
}

.page-about .year-block__text {
  margin: 14px 0 0;
  max-width: 62ch;
  font-size: 16px;
  line-height: 1.72;
  color: rgba(244, 247, 245, .78);
}

.page-about .year-block__media {
  margin: 20px 0 0;
}

.page-about .year-block__media img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* 年份轴高亮当前目标（支持 :has 时增强） */
.page-about .about-timeline__grid:has(#year-2021:target) .about-rail__link[href="#year-2021"],
.page-about .about-timeline__grid:has(#year-2022:target) .about-rail__link[href="#year-2022"],
.page-about .about-timeline__grid:has(#year-2023:target) .about-rail__link[href="#year-2023"],
.page-about .about-timeline__grid:has(#year-2024:target) .about-rail__link[href="#year-2024"] {
  background: rgba(47, 240, 190, .16);
}

.page-about .about-timeline__grid:has(#year-2021:target) .about-rail__link[href="#year-2021"] .about-rail__year,
.page-about .about-timeline__grid:has(#year-2022:target) .about-rail__link[href="#year-2022"] .about-rail__year,
.page-about .about-timeline__grid:has(#year-2023:target) .about-rail__link[href="#year-2023"] .about-rail__year,
.page-about .about-timeline__grid:has(#year-2024:target) .about-rail__link[href="#year-2024"] .about-rail__year,
.page-about .about-timeline__grid:has(#year-2021:target) .about-rail__link[href="#year-2021"] .about-rail__tag,
.page-about .about-timeline__grid:has(#year-2022:target) .about-rail__link[href="#year-2022"] .about-rail__tag,
.page-about .about-timeline__grid:has(#year-2023:target) .about-rail__link[href="#year-2023"] .about-rail__tag,
.page-about .about-timeline__grid:has(#year-2024:target) .about-rail__link[href="#year-2024"] .about-rail__tag {
  color: var(--cyan);
}

/* ---------- 五条内容线 ---------- */
.page-about .about-lines {
  padding: clamp(52px, 9vw, 104px) 0;
  background:
    radial-gradient(80% 60% at 88% 0%, rgba(255, 90, 43, .12), transparent 60%),
    var(--ink);
}

.page-about .about-lines__lede {
  margin-top: 16px;
  max-width: 56ch;
}

.page-about .line-list {
  display: grid;
  gap: 1px;
  margin: clamp(30px, 5vw, 52px) 0 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .line-item {
  position: relative;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 16px;
  padding: 22px 18px 22px 20px;
  background: rgba(6, 18, 15, .86);
  transition: background .22s var(--about-ease);
}

.page-about .line-item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: var(--about-line-thick);
  background: var(--cyan);
  transform: scaleY(0);
  transform-origin: top;
  transition: transform .28s var(--about-ease);
}

.page-about .line-item--cyan::before { background: var(--cyan); }
.page-about .line-item--yellow::before { background: var(--yellow); }
.page-about .line-item--blue::before { background: var(--blue-l); }
.page-about .line-item--violet::before { background: var(--violet-l); }
.page-about .line-item--orange::before { background: var(--orange); }

.page-about .line-item:hover,
.page-about .line-item:focus-within {
  background: rgba(11, 59, 46, .82);
}

.page-about .line-item:hover::before,
.page-about .line-item:focus-within::before {
  transform: scaleY(1);
}

.page-about .line-item__no {
  font-family: var(--font-num);
  font-size: 20px;
  font-weight: 700;
  line-height: 1.2;
  color: var(--grey);
  transition: color .22s var(--about-ease);
}

.page-about .line-item--cyan:hover .line-item__no { color: var(--cyan); }
.page-about .line-item--yellow:hover .line-item__no { color: var(--yellow); }
.page-about .line-item--blue:hover .line-item__no { color: var(--blue-l); }
.page-about .line-item--violet:hover .line-item__no { color: var(--violet-l); }
.page-about .line-item--orange:hover .line-item__no { color: var(--orange); }

.page-about .line-item__name {
  margin: 0;
  font-family: var(--font-head);
  font-size: clamp(18px, 3vw, 23px);
  font-weight: 700;
  color: var(--paper);
}

.page-about .line-item__desc {
  margin: 8px 0 0;
  max-width: 58ch;
  font-size: 15.5px;
  line-height: 1.7;
  color: rgba(244, 247, 245, .74);
}

.page-about .line-item__meta {
  display: block;
  margin: 12px 0 0;
  color: var(--grey);
}

/* ---------- 数据工序 ---------- */
.page-about .about-flow {
  padding: clamp(52px, 9vw, 104px) 0;
  background:
    linear-gradient(180deg, var(--paper) 0%, #E7EDE9 100%);
  color: var(--ink);
}

.page-about .about-flow__title {
  color: var(--green);
}

.page-about .about-flow__head .eyebrow {
  color: var(--green);
}

.page-about .about-flow__lede {
  color: rgba(6, 18, 15, .68);
  margin-top: 16px;
  max-width: 58ch;
}

.page-about .flow-grid {
  display: grid;
  gap: clamp(24px, 4vw, 44px);
  margin-top: clamp(30px, 5vw, 52px);
}

.page-about .flow-media {
  margin: 0;
  border: 1px solid rgba(11, 59, 46, .16);
  box-shadow: 0 22px 50px -40px rgba(6, 18, 15, .9);
}

.page-about .flow-media img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.page-about .about-flow .media-caption {
  color: rgba(6, 18, 15, .6);
}

.page-about .flow-steps {
  display: grid;
  gap: 12px;
  align-content: start;
}

.page-about .flow-step {
  border: 1px solid rgba(11, 59, 46, .18);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, .72);
  box-shadow: 0 16px 36px -34px rgba(6, 18, 15, .9);
  overflow: hidden;
  transition: border-color .2s var(--about-ease), background .2s var(--about-ease);
}

.page-about .flow-step[open] {
  border-color: rgba(47, 240, 190, .9);
  background: #FFFFFF;
}

.page-about .flow-step__summary {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 16px 18px;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-head);
  font-size: 19px;
  font-weight: 700;
  color: var(--green);
}

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

.page-about .flow-step__summary:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: -2px;
}

.page-about .flow-step__index {
  color: var(--grey);
}

.page-about .flow-step__name {
  flex: 1 1 auto;
}

.page-about .flow-step__summary::after {
  content: "+";
  font-family: var(--font-num);
  font-size: 18px;
  color: var(--grey);
  transition: transform .2s var(--about-ease), color .2s var(--about-ease);
}

.page-about .flow-step[open] .flow-step__summary::after {
  content: "–";
  color: var(--green);
}

.page-about .flow-step__text {
  margin: 0;
  padding: 0 18px 18px;
  font-size: 15.5px;
  line-height: 1.72;
  color: rgba(6, 18, 15, .76);
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  padding: clamp(52px, 9vw, 104px) 0;
  background:
    radial-gradient(90% 70% at 0% 100%, rgba(138, 77, 232, .22), transparent 62%),
    linear-gradient(180deg, var(--green) 0%, #082A20 100%);
}

.page-about .about-team__lede {
  margin-top: 16px;
  max-width: 56ch;
}

.page-about .team-grid {
  display: grid;
  gap: clamp(24px, 4vw, 44px);
  margin-top: clamp(30px, 5vw, 52px);
  align-items: start;
}

.page-about .team-cards {
  display: grid;
  gap: 14px;
}

.page-about .team-card {
  padding: 20px 18px;
  background: rgba(6, 18, 15, .58);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: transform .24s var(--about-ease), border-color .24s var(--about-ease), background .24s var(--about-ease);
}

.page-about .team-card:hover {
  transform: translateY(-3px);
  border-color: var(--line-strong);
  background: rgba(6, 18, 15, .8);
}

.page-about .team-card__name {
  margin: 0;
  font-family: var(--font-head);
  font-size: clamp(18px, 3vw, 22px);
  font-weight: 700;
  color: var(--cyan);
}

.page-about .team-card__desc {
  margin: 10px 0 0;
  font-size: 15.5px;
  line-height: 1.7;
  color: rgba(244, 247, 245, .76);
}

.page-about .team-media {
  margin: 0;
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.page-about .team-media img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* ---------- 服务对象 ---------- */
.page-about .about-audience {
  padding: clamp(52px, 9vw, 104px) 0;
  background: var(--ink);
}

.page-about .audience-list {
  display: grid;
  gap: 1px;
  margin: clamp(28px, 4.5vw, 48px) 0 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.page-about .audience-item {
  display: grid;
  gap: 8px;
  padding: 20px 4px;
  background: var(--ink);
  transition: background .22s var(--about-ease);
}

.page-about .audience-item:hover {
  background: rgba(11, 59, 46, .62);
}

.page-about .audience-item__role {
  color: var(--cyan);
  margin: 0;
}

.page-about .audience-item__text {
  margin: 0;
  max-width: 64ch;
  font-size: 15.5px;
  line-height: 1.72;
  color: rgba(244, 247, 245, .78);
}

/* ---------- 下一步 ---------- */
.page-about .about-next {
  padding: clamp(52px, 9vw, 104px) 0 clamp(60px, 10vw, 116px);
  background: linear-gradient(180deg, var(--paper) 0%, #E2E9E4 100%);
  color: var(--ink);
}

.page-about .about-next__title {
  color: var(--green);
  margin-top: 10px;
}

.page-about .about-next .eyebrow {
  color: var(--green);
}

.page-about .about-next__grid {
  display: grid;
  gap: clamp(26px, 4vw, 48px);
}

.page-about .next-list {
  display: grid;
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  background: rgba(11, 59, 46, .18);
  border: 1px solid rgba(11, 59, 46, .18);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .next-link {
  display: grid;
  gap: 6px;
  padding: 20px 18px;
  background: rgba(255, 255, 255, .82);
  text-decoration: none;
  transition: background .2s var(--about-ease), padding-left .24s var(--about-ease);
}

.page-about .next-link:hover,
.page-about .next-link:focus-visible {
  background: #FFFFFF;
  padding-left: 26px;
}

.page-about .next-link:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: -2px;
}

.page-about .next-link__label {
  color: var(--grey);
}

.page-about .next-link:hover .next-link__label,
.page-about .next-link:focus-visible .next-link__label {
  color: var(--green);
}

.page-about .next-link__name {
  font-family: var(--font-head);
  font-size: clamp(19px, 3.2vw, 24px);
  font-weight: 700;
  color: var(--green);
}

.page-about .next-link__hint {
  font-size: 15px;
  line-height: 1.65;
  color: rgba(6, 18, 15, .7);
}

/* ---------- 断点 ---------- */
@media (min-width: 760px) {
  .page-about .about-br {
    display: block;
  }

  .page-about .about-hero__stats {
    max-width: 520px;
  }

  .page-about .flow-grid {
    grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
    align-items: start;
  }

  .page-about .team-grid {
    grid-template-columns: minmax(0, 1.2fr) minmax(0, 0.8fr);
  }

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

  .page-about .audience-item {
    grid-template-columns: minmax(150px, 200px) minmax(0, 1fr);
    gap: 24px;
    align-items: baseline;
    padding: 22px 4px;
  }

  .page-about .about-next__grid {
    grid-template-columns: minmax(0, 0.75fr) minmax(0, 1.25fr);
    align-items: start;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.5fr) minmax(0, 0.85fr);
    align-items: end;
    gap: clamp(40px, 6vw, 72px);
  }

  .page-about .about-timeline__grid {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: clamp(32px, 5vw, 64px);
  }

  .page-about .about-rail__list {
    flex-direction: column;
    gap: 2px;
    padding: 6px;
    border-radius: var(--radius);
    overflow: visible;
  }

  .page-about .about-rail__link {
    justify-content: space-between;
    width: 100%;
    padding: 10px 12px;
    border-radius: 10px;
  }

  .page-about .about-rail__item + .about-rail__item {
    border-top: 1px solid var(--line);
  }

  .page-about .about-years {
    gap: 26px;
  }

  .page-about .year-block {
    padding: 26px 26px 28px;
  }

  .page-about .line-item {
    grid-template-columns: 74px minmax(0, 1fr);
    padding: 26px 26px 26px 30px;
    gap: 22px;
  }

  .page-about .line-item__no {
    font-size: 26px;
  }
}

@media (min-width: 1100px) {
  .page-about .about-hero__stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .year-block__head {
    gap: 18px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about [data-reveal],
  .page-about .year-block,
  .page-about .team-card,
  .page-about .next-link,
  .page-about .line-item::before {
    transition: none !important;
    transform: none !important;
  }
}