.page-about {
  --about-rail: 158px;
  --about-stream-gap: clamp(24px, 3vw, 52px);
  background: var(--sand);
  color: var(--ink);
}

/* 面包屑 */
.page-about .bd-crumbs {
  padding-top: clamp(18px, 3vw, 30px);
  padding-bottom: 6px;
}
.page-about .bd-crumbs ol {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--slate);
}
.page-about .bd-crumbs a {
  color: var(--slate);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 180ms ease-out, border-color 180ms ease-out;
}
.page-about .bd-crumbs a:hover,
.page-about .bd-crumbs a:focus-visible {
  color: var(--deep);
  border-color: var(--orange);
}
.page-about .bd-crumbs [aria-current="page"] {
  color: var(--deep);
  font-weight: 600;
}

/* 首屏 */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(140% 90% at 88% 8%, rgba(14, 74, 79, 0.85) 0%, rgba(14, 74, 79, 0) 58%),
    linear-gradient(168deg, var(--deep) 0%, var(--night) 100%);
  color: var(--sand);
  padding: clamp(44px, 7vw, 104px) 0 clamp(46px, 7vw, 104px);
}
.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: radial-gradient(circle, var(--mist) 1px, transparent 1.3px);
  background-size: 22px 22px;
  opacity: 0.14;
  pointer-events: none;
}
.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--orange) 0 18%, var(--grass) 18% 34%, var(--strait) 34% 100%);
}
.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
}
.page-about .about-hero__eyebrow {
  color: var(--mist);
  margin: 0;
  display: inline-block;
  border: 1px solid rgba(169, 214, 229, 0.36);
  border-radius: var(--pill);
  padding: 5px 14px;
}
.page-about .about-hero__title {
  margin: clamp(18px, 3vw, 30px) 0 0;
  color: var(--sand);
  font-weight: 200;
  letter-spacing: -0.02em;
  line-height: 1.02;
}
.page-about .about-hero__lede {
  max-width: 34em;
  margin: clamp(22px, 3.4vw, 40px) 0 0;
  font-size: clamp(15px, 1.3vw, 18px);
  line-height: 1.85;
  color: rgba(244, 238, 227, 0.82);
}
.page-about .about-hero__stats {
  list-style: none;
  margin: clamp(30px, 5vw, 56px) 0 0;
  padding: clamp(20px, 3vw, 30px) 0 0;
  border-top: 1px solid var(--hair-light);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px 22px;
}
.page-about .about-hero__stats li {
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-width: 0;
}
.page-about .about-hero__stats .bd-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(26px, 3.4vw, 42px);
  font-weight: 600;
  line-height: 1;
  color: var(--orange);
}
.page-about .about-hero__stats li > span:last-child {
  font-size: 13px;
  letter-spacing: 0.05em;
  color: rgba(244, 238, 227, 0.68);
}

/* 主体两栏：索引窄栏 + 长卷正文 */
.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--about-stream-gap);
  padding-top: clamp(44px, 6vw, 96px);
  padding-bottom: clamp(48px, 7vw, 110px);
}
.page-about .about-rail {
  border-top: 2px solid var(--ink);
  padding-top: 12px;
}
.page-about .about-rail__label {
  margin: 0 0 10px;
  color: var(--slate);
}
.page-about .about-rail__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.page-about .about-rail__list a {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 6px 12px;
  border: 1px solid var(--hair);
  border-radius: var(--pill);
  font-size: 13px;
  color: var(--slate);
  text-decoration: none;
  background: var(--paper);
  transition: color 180ms ease-out, border-color 180ms ease-out, background-color 180ms ease-out;
}
.page-about .about-rail__list a:hover,
.page-about .about-rail__list a:focus-visible {
  color: var(--deep);
  border-color: var(--orange);
  background: var(--sand-2);
}
.page-about .about-rail__list .bd-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--orange);
}

/* 章节通用 */
.page-about .about-stream {
  min-width: 0;
}
.page-about .about-chapter {
  scroll-margin-top: 110px;
  padding-bottom: clamp(48px, 7vw, 96px);
  margin-bottom: clamp(48px, 7vw, 96px);
  border-bottom: 1px solid var(--hair);
}
.page-about .about-chapter:last-child {
  border-bottom: 0;
  margin-bottom: 0;
}
.page-about .about-chapter__head {
  display: flex;
  align-items: baseline;
  gap: clamp(12px, 2vw, 22px);
  margin-bottom: clamp(16px, 2.4vw, 28px);
}
.page-about .about-chapter__num {
  flex: none;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(20px, 2.4vw, 30px);
  font-weight: 500;
  color: var(--orange);
  letter-spacing: 0.02em;
  line-height: 1;
  border-bottom: 3px solid var(--orange);
  padding-bottom: 4px;
}
.page-about .about-chapter__lede {
  max-width: 40em;
  margin: 0 0 clamp(22px, 3vw, 36px);
  font-size: clamp(16px, 1.25vw, 18px);
  line-height: 1.8;
  color: var(--ink);
}
.page-about .about-note {
  margin: clamp(22px, 3vw, 34px) 0 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--slate);
  border-left: 3px solid var(--sand-2);
  padding-left: 14px;
}
.page-about .about-note a {
  color: var(--deep);
  text-decoration: none;
  border-bottom: 1px solid var(--orange);
}
.page-about .about-note a:hover,
.page-about .about-note a:focus-visible {
  color: var(--orange);
}

/* 图 */
.page-about .about-chapter__figure {
  margin: 0;
  border: 1px solid var(--hair);
  background: var(--paper);
  box-shadow: var(--paper-shadow);
}
.page-about .about-chapter__figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 14 / 10;
  object-fit: cover;
}
.page-about .about-chapter__figure--wide img {
  aspect-ratio: 3 / 2;
}
.page-about .about-chapter__figure--panorama img {
  aspect-ratio: 14 / 9;
}

/* 01 章节 */
.page-about .about-chapter__split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 3vw, 36px);
}
.page-about .about-chapter__text p {
  margin: 0 0 1.1em;
}
.page-about .about-chapter__text p:first-child::first-letter {
  font-size: 2.6em;
  line-height: 0.9;
  float: left;
  padding: 4px 10px 0 0;
  color: var(--strait);
  font-weight: 600;
}

/* 02 字段带 */
.page-about .about-fields {
  list-style: none;
  margin: 0 0 clamp(28px, 4vw, 44px);
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--hair);
  border: 1px solid var(--hair);
}
.page-about .about-fields li {
  background: var(--paper);
  padding: 12px 14px;
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 14px;
  color: var(--ink);
}
.page-about .about-fields .bd-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--orange);
  background: var(--sand-2);
  padding: 2px 6px;
  border-radius: 2px;
}
.page-about .about-checkflow {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--gap);
  margin-bottom: clamp(28px, 4vw, 44px);
}
.page-about .about-checkflow__step {
  padding: clamp(18px, 2.4vw, 26px);
  border-top: 2px solid var(--strait);
}
.page-about .about-checkflow__step p {
  margin: 0.6em 0 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--slate);
}
.page-about .about-checkflow__no {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--orange);
}

/* 03 团队 */
.page-about .about-team {
  margin-bottom: clamp(10px, 2vw, 18px);
}
.page-about .about-team__row {
  display: flex;
  gap: 3px;
  height: clamp(62px, 9vw, 92px);
  border: 1px solid var(--hair);
  background: var(--paper);
  padding: 3px;
}
.page-about .about-team__seg {
  position: relative;
  display: flex;
  align-items: flex-end;
  padding: 10px 12px;
  border-radius: 2px;
  transition: flex-grow 220ms ease-out, filter 220ms ease-out;
  outline-offset: 3px;
}
.page-about .about-team__seg .bd-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(18px, 2.2vw, 28px);
  font-weight: 600;
  line-height: 1;
  color: var(--sand);
}
.page-about .about-team__seg--a {
  flex: 21 1 0;
  background: var(--strait);
}
.page-about .about-team__seg--b {
  flex: 9 1 0;
  background: var(--indigo);
}
.page-about .about-team__seg--c {
  flex: 8 1 0;
  background: var(--wine);
}
.page-about .about-team__pop {
  position: absolute;
  left: 0;
  bottom: calc(100% + 8px);
  z-index: 3;
  width: max-content;
  max-width: min(300px, 78vw);
  padding: 10px 12px;
  background: var(--deep);
  color: var(--sand);
  font-size: 13px;
  line-height: 1.7;
  border-radius: 3px;
  box-shadow: var(--lift-shadow);
  opacity: 0;
  transform: translateY(6px);
  pointer-events: none;
  transition: opacity 200ms ease-out, transform 200ms ease-out;
}
.page-about .about-team__seg:hover .about-team__pop,
.page-about .about-team__seg:focus-visible .about-team__pop,
.page-about .about-team__seg:focus-within .about-team__pop {
  opacity: 1;
  transform: translateY(0);
}
.page-about .about-team__legend {
  list-style: none;
  margin: 18px 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px 24px;
  font-size: 13px;
  color: var(--slate);
}
.page-about .about-team__legend li {
  display: flex;
  align-items: center;
  gap: 8px;
}
.page-about .about-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  display: inline-block;
  flex: none;
}
.page-about .about-dot--a { background: var(--strait); }
.page-about .about-dot--b { background: var(--indigo); }
.page-about .about-dot--c { background: var(--wine); }

/* 04 时间线 */
.page-about .about-chapter--timeline {
  position: relative;
  background: var(--indigo);
  color: var(--sand);
  padding: clamp(26px, 4vw, 48px) clamp(18px, 3vw, 40px);
  border-radius: var(--card-radius);
  border-bottom: 0;
  box-shadow: var(--lift-shadow);
}
.page-about .about-chapter--timeline .bd-h2 {
  color: var(--sand);
}
.page-about .about-chapter--timeline .about-chapter__lede {
  color: rgba(244, 238, 227, 0.8);
}
.page-about .about-timeline {
  list-style: none;
  margin: clamp(20px, 3vw, 34px) 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
}
.page-about .about-timeline__item {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
  padding-bottom: 12px;
  border-bottom: 1px solid rgba(244, 238, 227, 0.18);
}
.page-about .about-timeline__item:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}
.page-about .about-timeline__stamp {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  align-self: start;
  width: max-content;
  padding: 5px 12px 5px 10px;
  border-radius: var(--pill);
  background: var(--wine);
  color: var(--sand);
  font-size: 12px;
}
.page-about .about-timeline__stamp .bd-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-style: normal;
  font-size: 12px;
  letter-spacing: 0.06em;
}
.page-about .about-timeline__stamp em {
  font-style: normal;
  font-size: 11px;
  letter-spacing: 0.1em;
  color: rgba(244, 238, 227, 0.7);
}
.page-about .about-timeline__disc {
  border: 1px solid rgba(244, 238, 227, 0.22);
  border-radius: 3px;
  background: rgba(6, 23, 38, 0.32);
  overflow: hidden;
}
.page-about .about-timeline__disc > summary {
  cursor: pointer;
  padding: 12px 14px;
  font-size: 15px;
  font-weight: 600;
  color: var(--sand);
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  transition: background-color 200ms ease-out;
}
.page-about .about-timeline__disc > summary::-webkit-details-marker { display: none; }
.page-about .about-timeline__disc > summary::after {
  content: "+";
  flex: none;
  font-family: var(--font-mono);
  font-size: 16px;
  color: var(--orange);
  transition: transform 220ms ease-out;
}
.page-about .about-timeline__disc[open] > summary::after {
  content: "−";
}
.page-about .about-timeline__disc > summary:hover,
.page-about .about-timeline__disc > summary:focus-visible {
  background: rgba(255, 122, 41, 0.14);
}
.page-about .about-timeline__disc .bd-disclosure__body {
  padding: 0 14px 14px;
  font-size: 14px;
  line-height: 1.85;
  color: rgba(244, 238, 227, 0.82);
}
.page-about .about-timeline__disc .bd-disclosure__body p {
  margin: 0;
}

/* 05 协作网络 */
.page-about .about-network {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 3vw, 34px);
  align-items: start;
  margin-bottom: clamp(24px, 4vw, 40px);
}
.page-about .about-map {
  width: 100%;
  height: auto;
  background: var(--strait);
  border-radius: var(--card-radius);
  display: block;
}
.page-about .about-map__grid line {
  stroke: var(--mist);
  stroke-width: 1;
  opacity: 0.2;
}
.page-about .about-map__nodes circle {
  fill: var(--orange);
  opacity: 0.92;
}
.page-about .about-map__nodes circle:first-child {
  fill: var(--sand);
}
.page-about .about-network__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 16px;
}
.page-about .about-network__list li {
  border-left: 2px solid var(--sand-2);
  padding-left: 14px;
}
.page-about .about-network__list .bd-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 24px;
  font-weight: 600;
  color: var(--deep);
  margin-right: 6px;
}
.page-about .about-network__list strong {
  font-size: 15px;
  font-weight: 600;
  color: var(--deep);
}
.page-about .about-network__list p {
  margin: 6px 0 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--slate);
}
.page-about .about-checklist {
  margin-top: clamp(24px, 4vw, 44px);
  padding: clamp(20px, 3vw, 34px);
  border-left: 4px solid var(--grass);
}
.page-about .about-checklist .bd-index {
  margin: 0;
  color: var(--grass);
}
.page-about .about-checklist p {
  margin: 0.8em 0 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--slate);
  max-width: 40em;
}
.page-about .about-checklist .bd-actions {
  margin-top: clamp(18px, 2.6vw, 28px);
}

/* 06 存储与安全 */
.page-about .about-trust {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--gap);
}
.page-about .about-trust__item {
  padding: clamp(18px, 2.6vw, 28px);
  border-top: 2px solid var(--strait);
}
.page-about .about-trust__item p {
  margin: 0.7em 0 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--slate);
}
.page-about .about-trust__item a {
  color: var(--deep);
  border-bottom: 1px solid var(--orange);
  text-decoration: none;
}
.page-about .about-trust__item.bd-card--deep p {
  color: rgba(244, 238, 227, 0.8);
}

/* 07 服务区域与联系 */
.page-about .about-chapter--contact {
  background: var(--strait);
  color: var(--sand);
  border-radius: var(--card-radius);
  padding: clamp(26px, 4vw, 50px) clamp(18px, 3vw, 42px);
  border-bottom: 0;
  box-shadow: var(--lift-shadow);
}
.page-about .about-chapter--contact .bd-h2 {
  color: var(--sand);
}
.page-about .about-chapter--contact .about-chapter__num {
  color: var(--orange);
}
.page-about .about-contact {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 3vw, 36px);
  align-items: start;
}
.page-about .about-contact__text p {
  margin: 0 0 1em;
  font-size: 15px;
  line-height: 1.85;
  color: rgba(244, 238, 227, 0.84);
}
.page-about .about-contact__card {
  background: var(--paper);
  color: var(--ink);
  padding: clamp(20px, 2.8vw, 30px);
  border: 1px solid var(--sand-2);
}
.page-about .about-contact__card .bd-index {
  margin: 0 0 10px;
  color: var(--slate);
}
.page-about .about-contact__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
}
.page-about .about-contact__list li {
  display: grid;
  grid-template-columns: 72px minmax(0, 1fr);
  gap: 12px;
  align-items: baseline;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--hair);
}
.page-about .about-contact__list li > span {
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--slate);
}
.page-about .about-contact__list a {
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--deep);
  text-decoration: none;
  word-break: break-all;
  border-bottom: 1px solid transparent;
  transition: border-color 180ms ease-out, color 180ms ease-out;
}
.page-about .about-contact__list a:hover,
.page-about .about-contact__list a:focus-visible {
  color: var(--orange);
  border-color: var(--orange);
}
.page-about .about-contact__list address {
  font-style: normal;
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink);
}
.page-about .about-contact__note {
  margin: 16px 0 0;
  font-size: 13px;
  line-height: 1.8;
  color: var(--slate);
}
.page-about .about-contact__note a {
  color: var(--deep);
  border-bottom: 1px solid var(--orange);
  text-decoration: none;
}
.page-about .about-contact__actions {
  margin-top: clamp(22px, 3.4vw, 36px);
}

/* 状态与动效 */
.page-about [data-reveal] {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 480ms ease-out, transform 480ms ease-out;
}
.page-about [data-reveal].is-in {
  opacity: 1;
  transform: none;
}

/* 平板 */
@media (min-width: 700px) {
  .page-about .about-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .about-chapter__split {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr);
    align-items: start;
  }
  .page-about .about-fields {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .about-checkflow {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .about-trust {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .about-network {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.1fr);
  }
  .page-about .about-contact {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr);
  }
}

/* 桌面：常驻索引窄栏 */
@media (min-width: 960px) {
  .page-about .about-layout {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    column-gap: clamp(32px, 4vw, 68px);
  }
  .page-about .about-rail {
    position: sticky;
    top: 112px;
    align-self: start;
    border-top: 2px solid var(--ink);
  }
  .page-about .about-rail__list {
    flex-direction: column;
    flex-wrap: nowrap;
    gap: 2px;
  }
  .page-about .about-rail__list a {
    width: 100%;
    border: 0;
    border-left: 2px solid var(--sand-2);
    border-radius: 0;
    background: transparent;
    padding: 7px 0 7px 12px;
    justify-content: flex-start;
    transition: border-color 180ms ease-out, color 180ms ease-out, padding-left 180ms ease-out;
  }
  .page-about .about-rail__list a:hover,
  .page-about .about-rail__list a:focus-visible {
    border-left-color: var(--orange);
    color: var(--deep);
    background: transparent;
    padding-left: 16px;
  }
  .page-about .about-timeline__item {
    grid-template-columns: 190px minmax(0, 1fr);
    align-items: start;
    gap: 18px;
  }
  .page-about .about-timeline__stamp {
    justify-content: center;
  }
  .page-about .about-network__list {
    gap: 22px;
  }
}

@media (min-width: 1180px) {
  .page-about .about-chapter__split {
    grid-template-columns: minmax(0, 1.5fr) minmax(0, 1fr);
    column-gap: clamp(32px, 3.6vw, 56px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition-duration: 0.001ms !important;
    animation-duration: 0.001ms !important;
  }
  .page-about [data-reveal] {
    opacity: 1;
    transform: none;
  }
}