.page-about {
  --about-rule: rgba(185, 138, 75, .16);
  --about-tint: rgba(232, 117, 59, .08);
  background:
    repeating-linear-gradient(0deg, transparent 0 63px, var(--about-rule) 63px 64px),
    repeating-linear-gradient(90deg, transparent 0 63px, var(--about-rule) 63px 64px),
    var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  padding-bottom: clamp(2rem, 6vw, 4rem);
}

.page-about .breadcrumbs {
  padding: clamp(1rem, 3vw, 1.6rem) 0 0;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding: clamp(1rem, 3vw, 1.6rem) 0 clamp(1.5rem, 4vw, 2.5rem);
}

.page-about .about-hero__inner {
  position: relative;
  overflow: hidden;
  background: var(--porcelain);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: clamp(1.35rem, 4vw, 3rem);
  box-shadow: var(--shadow-soft);
}

.page-about .about-hero__inner::before {
  content: "";
  position: absolute;
  right: -70px;
  bottom: -100px;
  width: 250px;
  height: 250px;
  border-radius: 50%;
  background: radial-gradient(circle at 35% 35%, rgba(232, 117, 59, .26), transparent 70%);
  pointer-events: none;
}

.page-about .about-hero__inner::after {
  content: "";
  position: absolute;
  left: clamp(1.35rem, 4vw, 3rem);
  top: 0;
  width: 64px;
  height: 4px;
  border-radius: 0 0 4px 4px;
  background: var(--orange);
}

.page-about .about-hero .eyebrow {
  position: relative;
  margin: 0 0 .7rem;
  font-family: var(--font-mono);
  font-size: .75rem;
  letter-spacing: .12em;
  color: var(--copper);
}

.page-about h1 {
  position: relative;
  margin: 0 0 1rem;
  max-width: 20ch;
  font-family: var(--font-display);
  font-size: clamp(1.85rem, 6vw, 3.4rem);
  font-weight: 600;
  line-height: 1.18;
  letter-spacing: -.02em;
  color: var(--indigo);
}

.page-about .about-hero__lead {
  position: relative;
  margin: 0;
  max-width: 62ch;
  font-size: var(--fs-body);
  line-height: 1.85;
  color: #2c3444;
}

.page-about .about-hero__facts {
  position: relative;
  display: flex;
  flex-wrap: wrap;
  gap: .6rem clamp(1.2rem, 4vw, 2.6rem);
  margin: 1.5rem 0 0;
  padding: 1.1rem 0 0;
  list-style: none;
  border-top: 1px solid var(--line);
}

.page-about .about-hero__facts li {
  display: flex;
  align-items: baseline;
  gap: .45rem;
}

.page-about .about-hero__num {
  font-family: var(--font-mono);
  font-size: clamp(1.5rem, 4vw, 2rem);
  line-height: 1;
  color: var(--orange);
}

.page-about .about-hero__lab {
  font-size: .82rem;
  color: var(--celadon);
}

/* ---------- 两栏骨架 ---------- */
.page-about .about-layout {
  display: grid;
  gap: clamp(1.2rem, 3vw, 2rem);
  align-items: start;
}

.page-about .about-index {
  border-bottom: 1px solid var(--line);
  padding-bottom: .8rem;
}

.page-about .about-index__title {
  margin: 0 0 .55rem;
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .14em;
  color: var(--celadon);
}

.page-about .about-index__list {
  display: flex;
  gap: .4rem;
  margin: 0;
  padding: 0 0 .3rem;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-index__list a {
  display: flex;
  align-items: baseline;
  gap: .4rem;
  padding: .45rem .7rem;
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  background: var(--porcelain);
  color: var(--celadon);
  font-size: .85rem;
  text-decoration: none;
  white-space: nowrap;
  transition: color var(--dur), border-color var(--dur), background var(--dur);
}

.page-about .about-index__list a .mono {
  font-size: .72rem;
  color: var(--copper);
  transition: color var(--dur);
}

.page-about .about-index__list a:hover {
  color: var(--ink);
  border-color: var(--orange-soft);
}

.page-about .about-index__list a[aria-current="true"] {
  color: var(--porcelain);
  background: var(--indigo);
  border-color: var(--indigo);
}

.page-about .about-index__list a[aria-current="true"] .mono {
  color: var(--orange-soft);
}

/* ---------- 章节 ---------- */
.page-about .about-section {
  padding: clamp(1.6rem, 4vw, 2.8rem) 0;
  border-top: 1px solid var(--line);
}

.page-about .about-section:first-child {
  border-top: 0;
  padding-top: clamp(.6rem, 2vw, 1.2rem);
}

.page-about .about-section__head {
  display: flex;
  align-items: baseline;
  gap: .7rem;
  margin-bottom: 1.1rem;
}

.page-about .about-section__num {
  flex: none;
  font-family: var(--font-mono);
  font-size: clamp(1.5rem, 4vw, 2.2rem);
  line-height: 1;
  color: var(--copper);
}

.page-about .about-section__title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(1.25rem, 3.4vw, 1.75rem);
  font-weight: 600;
  line-height: 1.32;
  letter-spacing: -.01em;
  color: var(--indigo);
}

.page-about .about-prose p {
  margin: 0 0 1rem;
  max-width: 64ch;
  font-size: var(--fs-body);
  line-height: 1.85;
}

.page-about .about-prose p:last-child {
  margin-bottom: 0;
}

.page-about .about-lead {
  font-size: clamp(1.02rem, 2.4vw, 1.16rem);
  font-weight: 500;
  line-height: 1.75;
  color: var(--indigo);
}

.page-about .about-pull {
  margin: 1.4rem 0 0;
  padding: .3rem 0 .3rem 1rem;
  border-left: 3px solid var(--orange);
  font-size: clamp(1.02rem, 2.6vw, 1.22rem);
  line-height: 1.7;
  color: var(--indigo);
  transition: border-color var(--dur), color var(--dur);
}

.page-about .about-pull:hover {
  border-left-color: var(--teal);
  color: var(--teal);
}

/* ---------- 图文错位 ---------- */
.page-about .about-cols {
  display: grid;
  gap: clamp(1.2rem, 3vw, 2rem);
}

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

.page-about .media-frame {
  margin: 0;
}

.page-about .media-frame img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: var(--radius-md);
  object-fit: cover;
}

.page-about .media-frame__note {
  margin: .5rem 0 0;
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .04em;
  color: var(--celadon);
}

/* ---------- 技能树 ---------- */
.page-about .about-tree {
  margin-top: 1.4rem;
  padding: clamp(.8rem, 2.5vw, 1.3rem);
  background: var(--porcelain);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-soft);
}

.page-about .about-tree__scroll {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-tree svg {
  display: block;
  width: 100%;
  min-width: 520px;
  height: auto;
}

.page-about .tree-link {
  fill: none;
  stroke: var(--line-copper);
  stroke-width: 2;
}

.page-about .tree-root {
  fill: var(--indigo);
}

.page-about .tree-root__t {
  fill: var(--porcelain);
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 600;
}

.page-about .tree-root__n {
  fill: var(--orange-soft);
  font-family: var(--font-mono);
  font-size: 16px;
}

.page-about .tree-node {
  fill: var(--paper);
  stroke: var(--line);
  stroke-width: 1.5;
  transition: fill var(--dur), stroke var(--dur);
}

.page-about .tree-node:hover {
  fill: #ffffff;
  stroke: var(--orange);
}

.page-about .tree-node__t {
  fill: var(--ink);
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 600;
}

.page-about .tree-node__d {
  fill: var(--celadon);
  font-family: var(--font-body);
  font-size: 13px;
}

.page-about .about-tree__caption {
  margin: .9rem 0 0;
  padding-top: .8rem;
  border-top: 1px dashed var(--line);
  font-size: .86rem;
  line-height: 1.75;
  color: var(--celadon);
}

/* ---------- 历程 ---------- */
.page-about .about-timeline {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-timeline li {
  position: relative;
  padding: 0 0 1.5rem 1.9rem;
}

.page-about .about-timeline li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .5rem;
  width: .7rem;
  height: .7rem;
  border-radius: 50%;
  background: var(--porcelain);
  border: 2px solid var(--orange);
}

.page-about .about-timeline li::after {
  content: "";
  position: absolute;
  left: .33rem;
  top: 1.45rem;
  bottom: .1rem;
  width: 2px;
  background: var(--line);
}

.page-about .about-timeline li:last-child {
  padding-bottom: 0;
}

.page-about .about-timeline li:last-child::after {
  display: none;
}

.page-about .about-timeline__year {
  margin: 0 0 .2rem;
  font-size: clamp(1.3rem, 3.4vw, 1.7rem);
  line-height: 1;
  letter-spacing: .02em;
  color: var(--copper);
}

.page-about .about-timeline__t {
  margin: 0 0 .4rem;
  font-family: var(--font-display);
  font-size: 1.02rem;
  font-weight: 600;
  color: var(--ink);
}

.page-about .about-timeline p:not(.about-timeline__year) {
  margin: 0;
  max-width: 46ch;
  font-size: .94rem;
  line-height: 1.8;
}

/* ---------- 服务范围 ---------- */
.page-about .about-band {
  margin-bottom: 1.2rem;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--line);
}

.page-about .about-band .media-frame img {
  border-radius: 0;
}

.page-about .about-cadence {
  margin: 1.3rem 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: .6rem;
}

.page-about .about-cadence li {
  display: grid;
  gap: .2rem;
  padding: .85rem 1rem;
  background: var(--porcelain);
  border: 1px solid var(--line);
  border-left: 3px solid var(--orange-soft);
  border-radius: var(--radius-sm);
  transition: border-left-color var(--dur), transform var(--dur);
}

.page-about .about-cadence li:hover {
  border-left-color: var(--orange);
  transform: translateX(3px);
}

.page-about .about-cadence__when {
  font-size: .76rem;
  letter-spacing: .04em;
  color: var(--orange-dark);
}

.page-about .about-cadence__what {
  font-size: .94rem;
  line-height: 1.7;
}

/* ---------- 合作 ---------- */
.page-about .about-partners {
  background: var(--indigo);
  color: var(--porcelain);
  border-radius: var(--radius-lg);
  padding: clamp(1.2rem, 4vw, 2.2rem);
  display: grid;
  gap: 1.4rem;
}

.page-about .about-partners__text p {
  margin: 0 0 .9rem;
  max-width: 58ch;
  font-size: var(--fs-body);
  line-height: 1.85;
}

.page-about .about-partners__text p:last-child {
  margin-bottom: 0;
}

.page-about .about-partners__links {
  margin: 0;
  padding: 1.1rem 0 0;
  list-style: none;
  border-top: 1px solid rgba(251, 248, 242, .22);
  display: grid;
  gap: .45rem;
}

.page-about .about-partners__links a {
  display: block;
  padding: .6rem .85rem;
  border-radius: var(--radius-pill);
  background: rgba(251, 248, 242, .08);
  color: var(--porcelain);
  font-size: .9rem;
  text-decoration: none;
  transition: background var(--dur), color var(--dur);
}

.page-about .about-partners__links a:hover {
  background: var(--orange);
  color: var(--indigo);
}

/* ---------- 收尾 ---------- */
.page-about .about-section--last {
  border-top: 0;
  padding-bottom: 0;
}

.page-about .about-tail {
  padding: clamp(1.2rem, 4vw, 2rem);
  border: 1px solid var(--line-copper);
  border-radius: var(--radius-lg);
  background: var(--porcelain);
  box-shadow: var(--shadow-soft);
}

.page-about .about-tail__eyebrow {
  margin: 0 0 .5rem;
  font-size: .72rem;
  letter-spacing: .14em;
  color: var(--copper);
}

.page-about .about-tail__text {
  margin: 0 0 1.1rem;
  max-width: 58ch;
  font-size: var(--fs-body);
  line-height: 1.8;
}

.page-about .about-tail__actions {
  display: flex;
  flex-wrap: wrap;
  gap: .6rem;
}

/* ---------- 平板与桌面 ---------- */
@media (min-width: 720px) {
  .page-about .about-cadence li {
    grid-template-columns: 9.5rem 1fr;
    align-items: baseline;
    gap: 1rem;
  }

  .page-about .about-partners {
    grid-template-columns: minmax(0, 1.55fr) minmax(0, 1fr);
    align-items: start;
    gap: 2rem;
  }

  .page-about .about-partners__links {
    padding-top: 0;
    border-top: 0;
    border-left: 1px solid rgba(251, 248, 242, .22);
    padding-left: 1.4rem;
  }
}

@media (min-width: 860px) {
  .page-about .about-cols {
    grid-template-columns: minmax(0, 1fr) minmax(0, .82fr);
    align-items: start;
    gap: clamp(1.5rem, 4vw, 2.6rem);
  }

  .page-about .about-cols--timeline {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, .7fr);
  }

  .page-about .about-figure {
    margin-top: 1.6rem;
  }

  .page-about .about-band {
    margin-top: .4rem;
  }
}

@media (min-width: 980px) {
  .page-about .about-layout {
    grid-template-columns: 208px minmax(0, 1fr);
    gap: clamp(2rem, 5vw, 3.6rem);
  }

  .page-about .about-index {
    position: sticky;
    top: 96px;
    border-bottom: 0;
    padding-bottom: 0;
    border-right: 1px solid var(--line);
    padding-right: 1.1rem;
  }

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

  .page-about .about-index__list a {
    border: 0;
    border-left: 2px solid var(--line);
    border-radius: 0;
    background: transparent;
    padding: .55rem .4rem .55rem .85rem;
    white-space: normal;
  }

  .page-about .about-index__list a:hover {
    background: var(--about-tint);
    border-left-color: var(--orange-soft);
  }

  .page-about .about-index__list a[aria-current="true"] {
    background: var(--about-tint);
    border-left-color: var(--orange);
    color: var(--indigo);
  }

  .page-about .about-index__list a[aria-current="true"] .mono {
    color: var(--orange);
  }

  .page-about h1 {
    max-width: 22ch;
  }
}
<<<END>>>