.page-about {
  background: var(--porcelain);
  color: var(--ink);
}

/* ---------- 首屏 ---------- */
.page-about__hero {
  position: relative;
  padding-top: calc(var(--header-h) + 40px);
  padding-bottom: 0;
  background: linear-gradient(180deg, var(--night) 0%, var(--moss) 62%, var(--porcelain) 100%);
  color: var(--porcelain);
}

.page-about__hero-grid {
  row-gap: 24px;
}

.page-about__hero-copy {
  padding-bottom: 40px;
}

.page-about .breadcrumbs {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--pencil);
  margin-bottom: 28px;
}

.page-about .breadcrumbs a {
  color: var(--gold);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 160ms ease;
}

.page-about .breadcrumbs a:hover {
  border-bottom-color: var(--gold);
}

.page-about .breadcrumbs__sep {
  color: var(--stone);
}

.page-about__eyebrow {
  color: var(--gold-lit);
  margin: 0 0 18px;
}

.page-about__h1 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(2rem, 5.4vw, 3.6rem);
  line-height: 1.24;
  letter-spacing: -0.01em;
  margin: 0 0 28px;
  color: var(--paper);
}

.page-about__lede {
  max-width: 34em;
  font-size: 1.05rem;
  line-height: 1.9;
  color: rgba(245, 242, 234, 0.82);
  margin: 0 0 36px;
}

.page-about__hero-facts {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
  border-top: 1px solid var(--line-paper);
  padding-top: 24px;
}

.page-about__hero-facts li {
  display: flex;
  gap: 14px;
  align-items: baseline;
  font-size: 0.95rem;
  color: rgba(245, 242, 234, 0.75);
}

.page-about__hero-facts .mono {
  flex: 0 0 auto;
  min-width: 4.5em;
  color: var(--gold-lit);
  font-size: 0.92rem;
  font-weight: 700;
}

.page-about__hero-media {
  margin: 0;
  position: relative;
  background: var(--moss);
  border-top: 1px solid rgba(201, 162, 74, 0.35);
}

.page-about__hero-media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 1600 / 700;
  object-fit: cover;
  filter: saturate(0.9);
}

.page-about__hero-media .frame-media__caption {
  position: absolute;
  right: 0;
  bottom: 0;
  background: rgba(11, 15, 14, 0.66);
  color: var(--porcelain);
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.06em;
  padding: 8px 16px;
  margin: 0;
}

/* ---------- 主体栅格 ---------- */
.page-about__body {
  padding-top: 64px;
  padding-bottom: 96px;
  row-gap: 56px;
}

.page-about__section {
  margin-bottom: 88px;
}

.page-about__section:last-child {
  margin-bottom: 0;
}

.page-about__chapter-head {
  display: flex;
  align-items: baseline;
  gap: 20px;
  margin-bottom: 24px;
}

.page-about__h2 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.5rem, 3.4vw, 2.1rem);
  line-height: 1.35;
  margin: 0;
  color: var(--ink);
  position: relative;
}

.page-about__h2::after {
  content: "";
  display: block;
  width: 76px;
  height: 1px;
  margin-top: 16px;
  background: linear-gradient(90deg, var(--gold), rgba(201, 162, 74, 0));
}

.page-about__h3 {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.1rem;
  line-height: 1.55;
  margin: 0 0 10px;
  color: var(--ink);
}

.page-about__p {
  color: var(--stone);
  margin: 0 0 26px;
}

.page-about__p a {
  color: var(--forest);
  text-decoration: underline;
  text-decoration-color: var(--gold);
  text-underline-offset: 3px;
}

.page-about__section .rule {
  margin-top: 56px;
}

/* ---------- 01 维护内容 ---------- */
.page-about__maintain-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 2px;
  border-top: 1px solid var(--line-ink);
}

.page-about__maintain-list li {
  padding: 26px 0;
  border-bottom: 1px solid var(--line-ink);
  background: linear-gradient(90deg, rgba(201, 162, 74, 0.06), rgba(201, 162, 74, 0));
  padding-left: 22px;
  border-left: 2px solid transparent;
  transition: border-color 200ms ease, padding-left 200ms ease;
}

.page-about__maintain-list li:hover {
  border-left-color: var(--gold);
  padding-left: 28px;
}

.page-about__maintain-list p {
  margin: 0 0 8px;
  color: var(--stone);
}

.path-line {
  margin: 0;
  font-size: 0.84rem;
}

.path-line .mono {
  display: inline-block;
  background: rgba(14, 42, 34, 0.06);
  color: var(--forest);
  padding: 4px 10px;
  border-radius: var(--radius);
  border: 1px solid var(--line-ink);
}

/* ---------- 02 时间线 ---------- */
.page-about__timeline {
  list-style: none;
  margin: 8px 0 0;
  padding: 0 0 0 30px;
  position: relative;
}

.page-about__timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 32px;
  width: 2px;
  background: linear-gradient(180deg, var(--gold), var(--forest) 70%, rgba(47, 93, 74, 0.15));
}

.page-about__tl-item {
  position: relative;
  padding: 0 0 40px 8px;
}

.page-about__tl-mark {
  position: absolute;
  left: -30px;
  top: 6px;
  width: 12px;
  height: 12px;
  background: var(--paper);
  border: 2px solid var(--gold);
  transform: rotate(45deg);
}

.page-about__tl-tag {
  display: inline-block;
  margin: 0 0 10px;
}

.page-about__tl-item p:last-child {
  margin: 0;
  color: var(--stone);
  max-width: 40em;
}

/* ---------- 03 团队 ---------- */
.page-about__team-grid {
  row-gap: 20px;
  align-items: start;
  margin-bottom: 40px;
}

.page-about__team-card {
  padding: 30px 28px;
  border-left: 3px solid var(--forest);
}

.page-about__team-card:nth-child(2) {
  border-left-color: var(--gold);
}

.page-about__team-card:nth-child(3) {
  border-left-color: var(--coral);
}

.page-about__team-card .meta-label {
  color: var(--stone);
  margin: 0 0 12px;
}

.page-about__team-card p {
  margin: 0;
  color: var(--stone);
  font-size: 0.96rem;
}

.page-about__team-media {
  margin: 0;
}

.page-about__team-media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  border: 1px solid var(--line-ink);
  border-radius: var(--radius);
}

.page-about__team-media .frame-media__caption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.06em;
  color: var(--pencil);
}

/* ---------- 04 合作方向 ---------- */
.page-about__quadrant-wrap {
  display: grid;
  gap: 32px;
  align-items: start;
}

.page-about__quadrant {
  width: 100%;
  max-width: 480px;
  height: auto;
  color: var(--forest);
  background: var(--paper);
  border: 1px solid var(--line-ink);
  border-radius: var(--radius);
  padding: 8px;
}

.page-about__quad-label text {
  font-family: var(--font-display);
  fill: var(--ink);
}

.page-about__quad-label text:last-of-type {
  font-family: var(--font-body);
  fill: var(--stone);
}

.page-about__partner-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 16px;
}

.page-about__partner-list li {
  display: flex;
  gap: 14px;
  align-items: flex-start;
  color: var(--stone);
  padding-bottom: 16px;
  border-bottom: 1px solid var(--line-ink);
}

.page-about__partner-list li:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.page-about__partner-list .mono-tag {
  flex: 0 0 auto;
}

/* ---------- 05 手册编排 ---------- */
.page-about__handbook-grid {
  row-gap: 32px;
  align-items: start;
}

.page-about__handbook-media {
  margin: 0;
}

.page-about__handbook-media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 4;
  object-fit: cover;
  border: 1px solid var(--line-ink);
  border-radius: var(--radius);
}

.page-about__handbook-media .frame-media__caption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.06em;
  color: var(--pencil);
}

.page-about__accordion {
  display: grid;
  gap: 2px;
  border-top: 1px solid var(--line-ink);
}

.page-about__fold {
  border-bottom: 1px solid var(--line-ink);
  background: var(--paper);
}

.page-about__fold summary {
  cursor: pointer;
  padding: 18px 20px;
  display: flex;
  align-items: center;
  gap: 14px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1rem;
  color: var(--ink);
  list-style: none;
  transition: background 180ms ease;
}

.page-about__fold summary::-webkit-details-marker {
  display: none;
}

.page-about__fold summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  color: var(--gold);
  font-size: 1.1rem;
  transition: transform 180ms ease;
}

.page-about__fold[open] summary::after {
  transform: rotate(45deg);
}

.page-about__fold summary:hover {
  background: rgba(201, 162, 74, 0.07);
}

.page-about__fold p {
  margin: 0;
  padding: 0 20px 20px;
  color: var(--stone);
  font-size: 0.94rem;
}

/* ---------- 06 下一步 ---------- */
.page-about__section--close {
  background: linear-gradient(160deg, var(--moss) 0%, var(--night) 100%);
  border-radius: var(--radius);
  padding: 48px 32px 40px;
  margin-left: calc(var(--gutter) * -0.5);
  margin-right: calc(var(--gutter) * -0.5);
}

.page-about__section--close .page-about__h2,
.page-about__section--close .page-about__h3 {
  color: var(--paper);
}

.page-about__section--close .chapter-num {
  color: rgba(230, 200, 120, 0.55);
}

.page-about__section--close .page-about__p {
  color: rgba(245, 242, 234, 0.78);
}

.page-about__next {
  list-style: none;
  margin: 32px 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about__next-card {
  display: grid;
  gap: 6px;
  padding: 22px 22px 20px;
  background: rgba(253, 251, 246, 0.06);
  border: 1px solid rgba(201, 162, 74, 0.32);
  border-radius: var(--radius);
  text-decoration: none;
  color: var(--porcelain);
  transition: background 200ms ease, border-color 200ms ease, transform 200ms ease;
}

.page-about__next-card:hover,
.page-about__next-card:focus-visible {
  background: rgba(253, 251, 246, 0.12);
  border-color: var(--gold);
  transform: translateY(-2px);
}

.page-about__next-card .meta-label {
  color: var(--gold-lit);
  margin: 0;
}

.page-about__next-card strong {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--paper);
}

.page-about__next-card span:not(.meta-label):not(.mono) {
  color: rgba(245, 242, 234, 0.72);
  font-size: 0.92rem;
}

.page-about__next-path {
  color: var(--gold);
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  margin-top: 4px;
  opacity: 0.75;
  transition: opacity 200ms ease;
}

.page-about__next-card:hover .page-about__next-path {
  opacity: 1;
}

.page-about__close-note {
  margin: 28px 0 0;
  font-size: 0.9rem;
  color: rgba(245, 242, 234, 0.68);
}

.page-about__close-note a {
  color: var(--gold-lit);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- 右侧窄栏 ---------- */
.page-about__rail-card {
  padding: 24px 22px;
  margin-bottom: 18px;
}

.page-about__rail-card .meta-label {
  color: var(--stone);
  margin: 0 0 16px;
}

.page-about__rail-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 2px;
}

.page-about__rail-list li {
  font-size: 0.88rem;
  color: var(--stone);
  padding: 9px 12px;
  border-left: 2px solid transparent;
  transition: color 200ms ease, border-color 200ms ease, background 200ms ease;
}

.page-about__rail-list li .mono {
  color: var(--forest);
  font-weight: 700;
  margin-right: 6px;
}

.page-about__rail-list li.is-current {
  border-left-color: var(--gold);
  background: rgba(201, 162, 74, 0.09);
  color: var(--ink);
}

.page-about__rail-card--soft p {
  margin: 0;
  font-size: 0.88rem;
  color: var(--stone);
  line-height: 1.75;
}

.page-about__rail-card--soft a {
  color: var(--forest);
  text-decoration: underline;
  text-decoration-color: var(--gold);
  text-underline-offset: 3px;
}

.page-about__rail-card--soft .mono {
  background: rgba(14, 42, 34, 0.07);
  padding: 1px 6px;
  border-radius: var(--radius);
  font-size: 0.82rem;
  color: var(--forest);
}

@media (prefers-reduced-motion: reduce) {
  .page-about__maintain-list li,
  .page-about__next-card,
  .page-about__fold summary::after,
  .page-about__next-path,
  .page-about__rail-list li {
    transition: none;
  }
}

/* ---------- 响应式 ---------- */
@media (max-width: 1023px) {
  .page-about__side {
    order: 2;
  }

  .page-about .rail-sticky {
    position: static;
  }

  .page-about__rail-card {
    margin-bottom: 16px;
  }

  .page-about__section--close {
    margin-left: 0;
    margin-right: 0;
    padding: 40px 24px 34px;
  }
}

@media (min-width: 720px) {
  .page-about__quadrant-wrap {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.1fr);
    gap: 40px;
  }

  .page-about__next {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
  }
}

@media (min-width: 1024px) {
  .page-about__hero {
    padding-top: calc(var(--header-h) + 72px);
  }

  .page-about__hero-grid {
    padding-bottom: 56px;
  }

  .page-about__body {
    padding-top: 88px;
    padding-bottom: 120px;
  }

  .page-about__section {
    margin-bottom: 112px;
  }

  .page-about__handbook-grid .col-side {
    order: 0;
  }
}

@media (max-width: 640px) {
  .page-about__h1 {
    font-size: clamp(1.7rem, 7.6vw, 2.2rem);
  }

  .page-about__hero-facts li {
    flex-direction: column;
    gap: 4px;
  }

  .page-about__hero-facts .mono {
    min-width: 0;
  }

  .page-about__timeline {
    padding-left: 24px;
  }

  .page-about__tl-mark {
    left: -24px;
  }

  .page-about__chapter-head {
    gap: 14px;
  }

  .page-about__maintain-list li {
    padding-left: 16px;
  }
}
</｜｜DSML｜｜ parameter>
</｜｜DSML｜｜ invoke>
</｜｜DSML｜｜ calls>