.page-about {
  --about-line: rgba(242, 235, 221, 0.13);
  --about-soft: rgba(242, 235, 221, 0.68);
  background: var(--ink);
  color: var(--paper);
  font-family: var(--font-body);
  overflow-x: hidden;
}

.page-about .about-crumb {
  padding-top: 16px;
}

.page-about .crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--stone);
}

.page-about .crumbs a {
  color: var(--stone);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 180ms var(--ease), border-color 180ms var(--ease);
}

.page-about .crumbs a:hover,
.page-about .crumbs a:focus-visible {
  color: var(--signal);
  border-bottom-color: var(--signal);
}

.page-about .crumbs__sep {
  color: var(--teal);
}

/* 首屏 */
.about-hero {
  position: relative;
  padding: clamp(18px, 3.4vw, 38px) 0 clamp(26px, 4vw, 48px);
  border-bottom: 1px solid var(--about-line);
  background:
    radial-gradient(90% 120% at 6% -12%, rgba(255, 107, 44, 0.16), transparent 58%),
    linear-gradient(180deg, var(--ink-deep) 0%, var(--ink) 80%);
}

.about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, rgba(46, 90, 90, 0.22) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(46, 90, 90, 0.22) 1px, transparent 1px);
  background-size: 64px 64px;
  -webkit-mask-image: linear-gradient(118deg, rgba(0, 0, 0, 0.6), transparent 62%);
  mask-image: linear-gradient(118deg, rgba(0, 0, 0, 0.6), transparent 62%);
  pointer-events: none;
}

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

.about-hero__inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(16px, 3vw, 30px);
  align-items: end;
}

.about-hero__plate {
  display: flex;
  flex-direction: row;
  align-items: flex-end;
  justify-content: space-between;
  gap: 12px;
  padding: 14px 16px;
  border: 1px solid var(--signal);
  background: linear-gradient(155deg, rgba(255, 107, 44, 0.15), rgba(255, 107, 44, 0.02));
  box-shadow: 6px 6px 0 rgba(255, 107, 44, 0.1);
}

.about-hero__code {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(34px, 7vw, 64px);
  line-height: 0.9;
  letter-spacing: -0.03em;
  color: var(--signal);
}

.about-hero__plate-label {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.14em;
  color: var(--paper);
  opacity: 0.72;
  text-align: right;
}

.about-hero__kicker {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--celadon);
}

.about-hero__title {
  margin: 0 0 16px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(29px, 5.2vw, 60px);
  line-height: 1.04;
  letter-spacing: -0.02em;
  max-width: 19ch;
}

.about-hero__lead {
  margin: 0;
  max-width: 60ch;
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.8;
  color: var(--about-soft);
}

.about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(22px, 4vw, 42px) 0 0;
  background: var(--about-line);
  border-top: 1px solid var(--about-line);
}

.about-stats__item {
  display: flex;
  flex-direction: column-reverse;
  gap: 6px;
  padding: 16px 14px 6px;
  background: var(--ink);
}

.about-stats dd {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(26px, 3.4vw, 40px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.about-stats dt {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.1em;
  color: var(--stone);
}

/* 主体两栏 */
.about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 4vw, 44px);
  max-width: var(--wrap);
  margin: 0 auto;
  padding: clamp(30px, 5vw, 58px) var(--gutter) clamp(48px, 7vw, 84px);
}

.about-rail {
  position: relative;
}

.about-rail__title {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.18em;
  color: var(--teal);
}

.page-about .coord-rail__list {
  list-style: none;
  margin: 0;
  padding: 0 0 6px;
  display: flex;
  gap: 6px;
  overflow-x: auto;
  scrollbar-width: thin;
}

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

.page-about .coord-rail__link {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 7px 10px;
  font-size: 13px;
  color: var(--about-soft);
  text-decoration: none;
  border: 1px solid var(--about-line);
  white-space: nowrap;
  transition: color 180ms var(--ease), border-color 180ms var(--ease);
}

.page-about .coord-rail__link:hover,
.page-about .coord-rail__link:focus-visible,
.page-about .coord-rail__link[data-active] {
  color: var(--signal);
  border-color: var(--signal);
}

.page-about .coord-rail__code {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.06em;
  color: var(--stone);
  transition: color 180ms var(--ease);
}

.page-about .coord-rail__link[data-active] .coord-rail__code {
  color: var(--signal);
}

/* 章节 */
.about-section {
  margin-top: clamp(26px, 4vw, 46px);
  padding-top: clamp(26px, 4vw, 44px);
  border-top: 1px solid var(--about-line);
}

.about-section:first-of-type {
  margin-top: 0;
  padding-top: 0;
  border-top: 0;
}

.page-about .section__index {
  display: inline-block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--signal);
}

.page-about .h2 {
  margin: 0 0 14px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(23px, 3.4vw, 38px);
  line-height: 1.16;
  letter-spacing: -0.015em;
  max-width: 24ch;
}

.about-lead {
  margin: 0 0 clamp(18px, 2.6vw, 28px);
  max-width: 62ch;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--about-soft);
}

.about-note {
  margin: 16px 0 0;
  max-width: 62ch;
  font-size: 14px;
  line-height: 1.8;
  color: var(--about-soft);
}

.page-about .media-frame {
  margin: 0 0 clamp(16px, 2.4vw, 24px);
}

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

.page-about .media-frame__caption {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.08em;
  line-height: 1.6;
  color: var(--stone);
}

/* 团队分工 */
.team-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(18px, 3vw, 34px);
  align-items: start;
}

.team-figure {
  margin: 0;
}

.role-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.role {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 12px;
  padding: 14px 0;
  border-top: 1px dashed var(--about-line);
}

.role:first-child {
  padding-top: 0;
  border-top: 0;
}

.role__no {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--dot, var(--signal));
  padding-top: 4px;
}

.role__no::after {
  content: "";
  display: block;
  width: 18px;
  height: 2px;
  margin-top: 8px;
  background: var(--dot, var(--signal));
}

.role__main {
  min-width: 0;
}

.role__name {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
  margin: 0 0 6px;
  font-size: 17px;
  font-weight: 700;
  color: var(--paper);
}

.role__num {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.08em;
  color: var(--stone);
}

.role__text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--about-soft);
}

/* 服务覆盖 */
.coverage-figure {
  margin-bottom: clamp(16px, 2.4vw, 24px);
}

.coverage-stats {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--about-line);
  border: 1px solid var(--about-line);
}

.coverage-stats li {
  padding: 14px 12px;
  background: var(--panel);
}

.coverage-stats__num {
  display: block;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(22px, 2.6vw, 30px);
  line-height: 1;
  color: var(--paper);
}

.coverage-stats__num--accent {
  color: var(--celadon);
}

.coverage-stats__label {
  display: block;
  margin-top: 6px;
  font-size: 12px;
  line-height: 1.55;
  color: var(--stone);
}

/* 发展历程 */
.history-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(18px, 3vw, 34px);
  align-items: start;
}

.history-figure {
  margin: 0;
}

.timeline {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 2px 0 2px 26px;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 10px;
  bottom: 12px;
  width: 1px;
  background: linear-gradient(180deg, var(--signal), rgba(255, 107, 44, 0.08));
}

.timeline__item {
  position: relative;
  padding-bottom: 20px;
}

.timeline__item:last-child {
  padding-bottom: 0;
}

.timeline__item::before {
  content: "";
  position: absolute;
  left: -25px;
  top: 5px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--ink);
  border: 2px solid var(--signal);
  transition: box-shadow 200ms var(--ease);
}

.timeline__item:first-child::before {
  background: var(--signal);
}

.timeline__item:hover::before {
  box-shadow: 0 0 0 4px rgba(255, 107, 44, 0.16);
}

.timeline__year {
  display: block;
  margin-bottom: 4px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--signal);
}

.timeline__text {
  margin: 0;
  max-width: 48ch;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--about-soft);
}

/* 校准与质检 */
.flow {
  list-style: none;
  counter-reset: flow;
  margin: 0 0 18px;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
}

.flow__step {
  position: relative;
  padding: 14px 14px 16px;
  border: 1px solid var(--teal);
  background: rgba(22, 41, 58, 0.6);
  transition: border-color 200ms var(--ease), transform 200ms var(--ease);
}

.flow__step::before {
  counter-increment: flow;
  content: "0" counter(flow);
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--signal);
}

.flow__step:hover {
  border-color: var(--celadon);
  transform: translateY(-2px);
}

.flow__name {
  margin: 0 0 6px;
  font-size: 15px;
  font-weight: 700;
  color: var(--paper);
}

.flow__text {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.72;
  color: var(--about-soft);
}

.quality-note {
  margin: 0;
  max-width: 62ch;
  padding: 10px 0 10px 14px;
  border-left: 2px solid var(--amber);
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--about-soft);
}

/* 坐标体系 */
.az-strip {
  display: grid;
  grid-template-columns: repeat(13, minmax(0, 1fr));
  gap: 4px;
  margin: 0 0 20px;
}

.az-strip span {
  display: grid;
  place-items: center;
  aspect-ratio: 1 / 1;
  font-family: var(--font-mono);
  font-size: 10px;
  color: var(--stone);
  border: 1px solid var(--about-line);
  background: rgba(22, 41, 58, 0.45);
}

.az-strip span.is-mark {
  color: var(--ink);
  background: var(--signal);
  border-color: var(--signal);
  font-weight: 700;
}

.coord-grid {
  list-style: none;
  margin: 0 0 16px;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px;
}

.coord-grid li {
  display: flex;
}

.coord-card {
  display: flex;
  flex-direction: column;
  gap: 6px;
  width: 100%;
  padding: 12px;
  border: 1px solid var(--about-line);
  background: var(--panel);
  color: var(--paper);
  text-decoration: none;
  transition: border-color 200ms var(--ease), transform 200ms var(--ease), background 200ms var(--ease);
}

.coord-card:hover,
.coord-card:focus-visible {
  border-color: var(--signal);
  transform: translateY(-2px);
}

.coord-card__code {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--signal);
}

.coord-card__name {
  font-size: 14px;
  font-weight: 600;
}

.coord-card--current {
  border-color: var(--celadon);
  background: rgba(111, 191, 155, 0.1);
}

.coord-card--current .coord-card__code {
  color: var(--celadon);
}

/* 合作与联系 */
.invite-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
  margin-bottom: clamp(20px, 3vw, 30px);
}

.invite-card {
  display: block;
  padding: 16px;
  border: 1px solid var(--about-line);
  background: linear-gradient(160deg, rgba(22, 41, 58, 0.92), rgba(11, 27, 43, 0.92));
  color: var(--paper);
  text-decoration: none;
  transition: border-color 200ms var(--ease), transform 200ms var(--ease);
}

.invite-card:hover,
.invite-card:focus-visible {
  border-color: var(--signal);
  transform: translateY(-2px);
}

.invite-card__title {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 8px;
  font-size: 16px;
  font-weight: 700;
}

.invite-card__arrow {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--signal);
}

.invite-card__text {
  display: block;
  font-size: 14px;
  line-height: 1.76;
  color: var(--about-soft);
}

.contact-block {
  padding: clamp(16px, 2.4vw, 26px);
  border: 1px solid var(--teal);
  border-left: 3px solid var(--signal);
  background: var(--panel);
}

.contact-rows {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin-bottom: 16px;
}

.contact-row__key {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.14em;
  color: var(--celadon);
}

.contact-row__val {
  margin: 0;
  font-size: 14px;
  line-height: 1.6;
  word-break: break-word;
}

.contact-row__val a {
  color: var(--paper);
  text-decoration: none;
  border-bottom: 1px solid var(--signal);
  transition: color 180ms var(--ease);
}

.contact-row__val a:hover,
.contact-row__val a:focus-visible {
  color: var(--signal);
}

.contact-note {
  margin: 0;
  padding-top: 14px;
  border-top: 1px dashed var(--about-line);
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--about-soft);
}

/* 响应式 */
@media (min-width: 640px) {
  .az-strip {
    grid-template-columns: repeat(26, minmax(0, 1fr));
  }

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

@media (min-width: 780px) {
  .about-hero__inner {
    grid-template-columns: minmax(140px, 0.85fr) minmax(0, 3.15fr);
    gap: clamp(24px, 4vw, 52px);
  }

  .about-hero__plate {
    flex-direction: column;
    align-items: flex-start;
    justify-content: space-between;
    min-height: 186px;
    padding: 18px 20px;
  }

  .about-hero__plate-label {
    text-align: left;
  }

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

  .coverage-stats {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }

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

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

  .contact-rows {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 880px) {
  .team-grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
  }

  .history-grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
  }
}

@media (min-width: 1000px) {
  .about-body {
    grid-template-columns: 148px minmax(0, 1fr);
    gap: clamp(32px, 4vw, 60px);
  }

  .about-rail {
    position: sticky;
    top: 92px;
    align-self: start;
  }

  .page-about .coord-rail__list {
    flex-direction: column;
    gap: 0;
    overflow: visible;
    padding-bottom: 0;
  }

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

  .page-about .coord-rail__link {
    padding: 10px 0;
    border: 0;
    border-top: 1px solid var(--about-line);
    white-space: normal;
  }

  .page-about .coord-rail__link[data-active] {
    border-top-color: var(--signal);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .coord-rail__link,
  .page-about .coord-rail__code,
  .coord-card,
  .invite-card,
  .flow__step,
  .timeline__item::before,
  .page-about .crumbs a {
    transition: none;
  }

  .coord-card:hover,
  .invite-card:hover,
  .flow__step:hover {
    transform: none;
  }
}

.page-about {
  --dot: transparent;
}