.page-about {
  --about-rail: 190px;
  --about-line: rgba(20, 17, 13, 0.09);
  background: var(--paper);
  color: var(--ink);
}

.page-about .shell {
  width: 100%;
  max-width: var(--shell);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

.page-about .shell--narrow {
  max-width: var(--shell-narrow);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: 22px 0 44px;
  border-bottom: 1px solid var(--about-line);
  overflow: hidden;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0 var(--gutter) auto auto;
  width: 120px;
  height: 120px;
  border-top: 1px solid var(--gold-28);
  border-right: 1px solid var(--gold-28);
  pointer-events: none;
  opacity: 0.65;
}

.page-about .about-hero .breadcrumbs {
  margin-bottom: 20px;
}

.page-about .about-hero__frame {
  position: relative;
  padding-left: 18px;
}

.page-about .about-hero__axis {
  position: absolute;
  left: 0;
  top: 4px;
  bottom: 4px;
  width: 2px;
  background: linear-gradient(180deg, var(--gold), var(--gold-12) 70%, transparent);
}

.page-about .about-hero__meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
}

.page-about .about-hero__code {
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--stone);
  text-transform: uppercase;
}

.page-about .about-hero__title {
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: clamp(29px, 7.4vw, 54px);
  line-height: 1.2;
  letter-spacing: -0.01em;
  margin: 0 0 18px;
  max-width: 17ch;
  text-wrap: balance;
}

.page-about .about-hero__lede {
  max-width: 62ch;
  color: var(--ink-soft);
  margin: 0;
}

.page-about .about-hero__figures {
  list-style: none;
  margin: 34px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--about-line);
  border-top: 1px solid var(--about-line);
  border-bottom: 1px solid var(--about-line);
}

.page-about .about-hero__figure {
  background: var(--paper);
  padding: 14px 16px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.page-about .about-hero__figure-num {
  font-size: 24px;
  line-height: 1.1;
  color: var(--ink);
  letter-spacing: 0.02em;
}

.page-about .about-hero__figure-label {
  font-size: 13px;
  color: var(--stone);
}

/* ---------- 通用分区节奏 ---------- */
.page-about .section {
  padding: 44px 0;
  border-bottom: 1px solid var(--about-line);
}

.page-about .section:last-of-type {
  border-bottom: 0;
}

.page-about .section--sand {
  background: linear-gradient(180deg, rgba(239, 227, 198, 0.72), rgba(239, 227, 198, 0.42));
}

/* ---------- 01 为什么存在 ---------- */
.page-about .about-why__body .section__title {
  max-width: 26ch;
}

.page-about .about-why__body .prose {
  margin-top: 22px;
}

.page-about .why-list {
  list-style: none;
  margin: 32px 0 0;
  padding: 0;
  display: grid;
  gap: 0;
}

.page-about .why-list__item {
  display: grid;
  gap: 6px;
  padding: 18px 0;
  border-top: 1px solid var(--about-line);
}

.page-about .why-list__item:last-child {
  border-bottom: 1px solid var(--about-line);
}

.page-about .why-list__key {
  font-family: var(--font-serif);
  font-size: 19px;
  font-weight: 600;
  color: var(--cinnabar);
  letter-spacing: 0.01em;
}

.page-about .why-list__text {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--ink-soft);
}

/* ---------- 02 时间线 ---------- */
.page-about .about-timeline .section__head {
  max-width: 640px;
}

.page-about .timeline {
  position: relative;
  margin-top: 30px;
  padding-left: 30px;
}

.page-about .timeline__rail {
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: linear-gradient(180deg, var(--gold-45), var(--gold-12) 82%, transparent);
}

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

.page-about .timeline__marker {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 8px;
}

.page-about .timeline__year {
  font-size: 15px;
  letter-spacing: 0.1em;
  color: var(--ink);
  background: var(--sand);
  padding: 3px 9px;
  border: 1px solid var(--gold-28);
}

.page-about .timeline__node {
  position: absolute;
  left: -30px;
  top: 12px;
  width: 12px;
  height: 12px;
  background: var(--cinnabar);
  transform: rotate(45deg);
  box-shadow: 0 0 0 4px rgba(247, 242, 231, 0.9);
}

.page-about .timeline__panel {
  border: 1px solid var(--about-line);
  border-left: 2px solid var(--gold-28);
  background: var(--cloud);
  transition: border-color 220ms var(--ease);
}

.page-about .timeline__panel:hover {
  border-left-color: var(--gold);
}

.page-about .timeline__panel .panel__trigger {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 14px;
  width: 100%;
  padding: 15px 16px;
  background: transparent;
  border: 0;
  text-align: left;
  cursor: pointer;
  color: var(--ink);
}

.page-about .timeline__panel .panel__trigger:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: -2px;
}

.page-about .timeline__stage {
  font-family: var(--font-serif);
  font-size: 17px;
  font-weight: 600;
  line-height: 1.5;
}

.page-about .timeline__panel .panel__icon {
  flex: none;
  font-size: 16px;
  line-height: 1.2;
  color: var(--gold);
  transition: transform 220ms var(--ease);
}

.page-about .timeline__panel .panel__trigger[aria-expanded="true"] .panel__icon {
  transform: rotate(180deg);
}

.page-about .timeline__panel .panel__body {
  padding: 0 16px 18px;
}

.page-about .timeline__text {
  margin: 0 0 12px;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--ink-soft);
}

.page-about .timeline__outcomes {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
}

.page-about .timeline__outcomes li {
  position: relative;
  padding-left: 18px;
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--stone);
}

.page-about .timeline__outcomes li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.62em;
  width: 8px;
  height: 1px;
  background: var(--gold);
}

.page-about .timeline__figure {
  margin: 8px 0 22px;
}

.page-about .timeline__figure .figure__caption {
  margin-top: 10px;
  font-size: 13px;
  color: var(--stone);
}

/* ---------- 03 团队 ---------- */
.page-about .crew {
  margin-top: 30px;
}

.page-about .crew__hub {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 18px 20px;
  border: 1px solid var(--gold-28);
  background: linear-gradient(120deg, rgba(233, 206, 140, 0.24), rgba(247, 242, 231, 0.4));
}

.page-about .crew__hub-num {
  font-size: 42px;
  line-height: 1;
  color: var(--ink);
  letter-spacing: 0.01em;
}

.page-about .crew__hub-label {
  font-size: 14px;
  color: var(--stone);
}

.page-about .crew__slots {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0;
}

.page-about .crew__slot {
  position: relative;
  padding: 20px 0 20px 22px;
  border-top: 1px solid var(--about-line);
}

.page-about .crew__slot:last-child {
  border-bottom: 1px solid var(--about-line);
}

.page-about .crew__slot::before {
  content: "";
  position: absolute;
  left: 0;
  top: 26px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  border: 1.5px solid var(--gold);
  background: var(--paper);
}

.page-about .crew__slot-num {
  display: inline-block;
  font-size: 20px;
  color: var(--jade);
  letter-spacing: 0.04em;
  padding: 2px 8px;
  background: rgba(47, 110, 99, 0.09);
}

.page-about .crew__slot-title {
  margin: 10px 0 8px;
  font-family: var(--font-serif);
  font-size: 19px;
  font-weight: 600;
  line-height: 1.45;
}

.page-about .crew__slot-text {
  margin: 0;
  max-width: 58ch;
  font-size: 15px;
  line-height: 1.82;
  color: var(--ink-soft);
}

/* ---------- 04 覆盖与网点 ---------- */
.page-about .reach {
  margin-top: 28px;
  display: grid;
  gap: 24px;
}

.page-about .reach__map {
  border: 1px solid var(--gold-28);
  background: rgba(255, 255, 255, 0.62);
  padding: 14px;
}

.page-about .reach__svg {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .reach__contour {
  fill: none;
  stroke: url(#reachGold);
  stroke-width: 1.6;
}

.page-about .reach__contour--soft {
  stroke: var(--gold-28);
  stroke-dasharray: 4 6;
}

.page-about .reach__dots circle {
  fill: var(--cinnabar);
  opacity: 0.85;
}

.page-about .reach__marks circle {
  fill: none;
  stroke: var(--jade);
  stroke-width: 1.2;
  opacity: 0.6;
}

.page-about .reach__caption {
  margin: 12px 0 0;
  font-size: 13px;
  line-height: 1.7;
  color: var(--stone);
}

.page-about .reach__list {
  margin: 0;
  display: grid;
  gap: 0;
}

.page-about .reach__row {
  display: grid;
  gap: 4px;
  padding: 14px 0;
  border-top: 1px solid var(--about-line);
}

.page-about .reach__row:last-child {
  border-bottom: 1px solid var(--about-line);
}

.page-about .reach__row-k {
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--stone);
}

.page-about .reach__row-v {
  margin: 0;
  font-size: 16px;
  font-family: var(--font-serif);
  font-weight: 600;
  color: var(--ink);
}

.page-about .reach__row-v.mono {
  font-family: var(--font-mono);
  font-weight: 500;
  font-size: 15px;
}

.page-about .reach__figure {
  margin: 32px 0 0;
}

.page-about .reach__figure .figure__caption {
  margin-top: 10px;
  font-size: 13px;
  color: var(--stone);
}

/* ---------- 05 协作生态 ---------- */
.page-about .about-eco .section__head {
  max-width: 660px;
}

.page-about .eco {
  margin-top: 30px;
}

.page-about .eco__nodes {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 10px;
  padding: 20px 18px;
  background: var(--cloud);
  border: 1px solid var(--about-line);
}

.page-about .eco__node {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 10px 14px;
  border-left: 3px solid var(--gold);
  background: var(--sand);
  width: 100%;
}

.page-about .eco__node--jade {
  border-left-color: var(--jade);
}

.page-about .eco__node--seal {
  border-left-color: var(--cinnabar);
}

.page-about .eco__node-num {
  font-size: 22px;
  color: var(--ink);
}

.page-about .eco__node-label {
  font-size: 14px;
  color: var(--ink-soft);
}

.page-about .eco__link {
  display: block;
  width: 1px;
  height: 18px;
  margin-left: 18px;
  background: var(--gold-45);
}

.page-about .eco__cols {
  margin-top: 26px;
  display: grid;
  gap: 26px;
}

.page-about .eco__prose p {
  max-width: 60ch;
}

.page-about .eco__figure {
  margin: 0;
}

.page-about .eco__figure .figure__caption {
  margin-top: 10px;
  font-size: 13px;
  color: var(--stone);
}

/* ---------- 06 服务承诺 ---------- */
.page-about .promise {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: grid;
  gap: 0;
}

.page-about .promise__item {
  padding: 18px 0;
  border-top: 1px solid var(--about-line);
  display: grid;
  gap: 8px;
}

.page-about .promise__item:last-child {
  border-bottom: 1px solid var(--about-line);
}

.page-about .promise__term {
  display: inline-block;
  justify-self: start;
  font-size: 14px;
  letter-spacing: 0.04em;
  color: var(--ink);
  background: var(--cloud);
  border: 1px solid var(--gold-28);
  padding: 5px 11px;
}

.page-about .promise__desc {
  margin: 0;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.82;
  color: var(--ink-soft);
}

/* ---------- 结语 ---------- */
.page-about .about-coda {
  padding: 52px 0 60px;
  background: var(--ink-soft);
  color: var(--paper);
  text-align: center;
}

.page-about .about-coda__seal {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 62px;
  height: 62px;
  margin-bottom: 22px;
  font-family: var(--font-serif);
  font-size: 30px;
  font-weight: 700;
  color: var(--paper);
  background: var(--cinnabar);
  box-shadow: 0 0 0 1px rgba(233, 206, 140, 0.5), 0 0 0 6px rgba(181, 52, 44, 0.12);
  border-radius: 3px;
}

.page-about .about-coda__text {
  margin: 0 auto 26px;
  max-width: 40ch;
  font-family: var(--font-serif);
  font-size: 19px;
  line-height: 1.75;
  color: rgba(247, 242, 231, 0.92);
}

.page-about .about-coda__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
}

.page-about .about-coda .btn--ghost {
  color: var(--paper);
  border-color: rgba(233, 206, 140, 0.55);
}

.page-about .about-coda .btn--ghost:hover {
  color: var(--ink-soft);
}

/* ---------- 平板 ---------- */
@media (min-width: 640px) {
  .page-about .about-hero {
    padding: 30px 0 56px;
  }

  .page-about .about-hero__frame {
    padding-left: 26px;
  }

  .page-about .about-hero__figures {
    grid-template-columns: repeat(3, 1fr);
  }

  .page-about .why-list__item {
    grid-template-columns: 150px 1fr;
    align-items: baseline;
    gap: 20px;
  }

  .page-about .reach__row {
    grid-template-columns: 180px 1fr;
    align-items: baseline;
    gap: 18px;
  }

  .page-about .promise__item {
    grid-template-columns: 190px 1fr;
    align-items: start;
    gap: 22px;
  }
}

/* ---------- 桌面 ---------- */
@media (min-width: 900px) {
  .page-about .about-hero {
    padding: 44px 0 72px;
  }

  .page-about .section {
    padding: 76px 0;
  }

  .page-about .timeline {
    padding-left: 46px;
    margin-top: 40px;
  }

  .page-about .timeline__rail {
    left: 9px;
  }

  .page-about .timeline__item {
    padding-bottom: 10px;
    display: grid;
    grid-template-columns: 130px 1fr;
    gap: 28px;
    align-items: start;
  }

  .page-about .timeline__marker {
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    margin-bottom: 0;
    padding-top: 8px;
  }

  .page-about .timeline__node {
    left: -42px;
    top: 20px;
  }

  .page-about .timeline__stage {
    font-size: 18px;
  }

  .page-about .timeline__figure {
    margin: 14px 0 26px;
  }

  .page-about .crew__hub {
    padding: 22px 26px;
  }

  .page-about .crew__hub-num {
    font-size: 52px;
  }

  .page-about .crew__slots {
    grid-template-columns: repeat(3, 1fr);
    gap: 0 26px;
    margin-top: 26px;
  }

  .page-about .crew__slot {
    padding: 22px 0 26px 20px;
    border-top: 1px solid var(--about-line);
  }

  .page-about .crew__slot--b {
    padding-top: 46px;
  }

  .page-about .crew__slot--c {
    padding-top: 70px;
  }

  .page-about .crew__slot::before {
    box-shadow: 0 0 0 6px rgba(247, 242, 231, 0.9);
  }

  .page-about .reach {
    grid-template-columns: 1.25fr 1fr;
    gap: 40px;
    align-items: start;
    margin-top: 36px;
  }

  .page-about .reach__figure {
    margin-top: 44px;
  }

  .page-about .eco__nodes {
    flex-direction: row;
    align-items: center;
    gap: 0;
    padding: 26px 24px;
  }

  .page-about .eco__node {
    width: auto;
    flex: 1 1 0;
    min-width: 0;
  }

  .page-about .eco__link {
    width: 46px;
    height: 1px;
    margin: 0 10px;
    flex: none;
  }

  .page-about .eco__cols {
    grid-template-columns: 1.35fr 1fr;
    gap: 44px;
    align-items: start;
    margin-top: 34px;
  }

  .page-about .about-coda {
    padding: 72px 0 80px;
  }

  .page-about .about-coda__text {
    font-size: 22px;
  }
}

@media (min-width: 1100px) {
  .page-about .about-hero__frame {
    padding-left: 34px;
  }

  .page-about .about-hero__title {
    max-width: 20ch;
  }
}

/* ---------- 动效 ---------- */
.page-about .about-hero__axis {
  transform-origin: top center;
}

@media (prefers-reduced-motion: no-preference) {
  .page-about.has-reveal .about-hero__axis {
    animation: about-axis-draw 420ms var(--ease) both;
  }
}

@keyframes about-axis-draw {
  from {
    transform: scaleY(0);
    opacity: 0;
  }
  to {
    transform: scaleY(1);
    opacity: 1;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .timeline__panel,
  .page-about .timeline__panel .panel__icon {
    transition: none;
  }
}