.page-about {
  --about-rail-w: 168px;
  --about-gap: clamp(24px, 3.6vw, 60px);
  --about-soft: rgba(232, 238, 255, 0.84);
  --about-soft-2: rgba(232, 238, 255, 0.82);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(24px, 4vw, 52px) 0 clamp(34px, 5vw, 68px);
  border-bottom: 1px solid var(--line);
  background:
    radial-gradient(120% 90% at 88% -10%, rgba(47, 227, 192, 0.10) 0%, transparent 55%),
    linear-gradient(180deg, var(--ink-2) 0%, var(--ink) 100%);
}

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

.page-about .about-hero__ring {
  position: absolute;
  top: -30vw;
  right: -26vw;
  width: 74vw;
  height: 74vw;
  max-width: 900px;
  max-height: 900px;
  border-radius: 50%;
  pointer-events: none;
  background: radial-gradient(circle, rgba(47, 227, 192, 0.13) 0%, transparent 62%);
}

.page-about .about-hero__ring::before,
.page-about .about-hero__ring::after {
  content: "";
  position: absolute;
  border-radius: 50%;
  border: 1px solid var(--line);
}

.page-about .about-hero__ring::before { inset: 16%; }
.page-about .about-hero__ring::after {
  inset: 33%;
  border-color: rgba(47, 227, 192, 0.30);
}

.page-about .about-hero__inner {
  max-width: 880px;
  margin-top: 18px;
}

.page-about .about-hero__inner .display-1 {
  margin: 12px 0 0;
}

.page-about .about-hero__inner .lede {
  margin: 18px 0 0;
  max-width: 66ch;
}

.page-about .about-facts {
  list-style: none;
  margin: clamp(28px, 4vw, 48px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-facts li {
  background: var(--ink-2);
  padding: 14px 16px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.page-about .about-facts__k {
  font-family: var(--font-sans);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.page-about .about-facts__v {
  font-family: var(--font-mono);
  font-size: 21px;
  font-weight: 600;
  line-height: 1.15;
  color: var(--neon);
}

/* ---------- 两栏骨架 ---------- */
.page-about .about-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
}

.page-about .about-content {
  min-width: 0;
}

/* ---------- 左侧坐标栏 ---------- */
.page-about .about-rail {
  padding: 22px 0 8px;
  border-bottom: 1px solid var(--line);
}

.page-about .about-rail__title {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.2em;
  color: var(--muted);
}

.page-about .about-rail__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 4px 18px;
}

.page-about .about-rail__link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.04em;
  color: var(--muted);
  text-decoration: none;
  padding: 5px 0;
  transition: color 0.22s var(--ease), border-color 0.22s var(--ease);
}

.page-about .about-rail__num {
  color: var(--orange);
  opacity: 0.85;
}

/* ---------- 章节 ---------- */
.page-about .about-section {
  padding: clamp(34px, 5vw, 62px) 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-section__head {
  margin-bottom: clamp(18px, 2.6vw, 30px);
}

.page-about .about-section__head .display-2 {
  margin: 10px 0 0;
}

.page-about .about-text {
  margin: 0 0 18px;
  max-width: 66ch;
  font-size: 16.5px;
  line-height: 1.78;
  color: var(--about-soft);
}

.page-about .about-note {
  margin: 22px 0 0;
  padding: 14px 16px;
  max-width: 72ch;
  border-left: 3px solid var(--orange);
  background: rgba(255, 154, 60, 0.06);
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--muted);
}

/* ---------- 服务范围卡片 ---------- */
.page-about .work-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin-top: 24px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .work-card {
  position: relative;
  background: var(--ink-2);
  padding: 22px 20px 26px;
}

.page-about .work-card::after {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 2px;
  height: 0;
  background: var(--orange);
  transition: height 0.34s var(--ease);
}

.page-about .work-card:hover::after,
.page-about .work-card:focus-within::after {
  height: 100%;
}

.page-about .work-card__idx {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--orange);
}

.page-about .work-card__title {
  margin: 12px 0 10px;
  font-family: var(--font-display);
  font-size: 21px;
  font-weight: 700;
  line-height: 1.35;
  color: var(--white);
}

.page-about .work-card p {
  margin: 0;
  font-size: 15px;
  line-height: 1.76;
  color: var(--about-soft);
}

/* ---------- 图片容器 ---------- */
.page-about .frame img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .about-origin__frame {
  margin: 0 0 clamp(26px, 3.4vw, 40px);
}

.page-about .about-team__frame,
.page-about .about-test__frame {
  margin: clamp(26px, 3.4vw, 40px) 0 0;
}

/* ---------- 时间轴 ---------- */
.page-about .tl {
  list-style: none;
  position: relative;
  margin: 6px 0 0;
  padding: 0;
}

.page-about .tl::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 12px;
  bottom: 18px;
  width: 1px;
  background: var(--line);
}

.page-about .tl__item {
  position: relative;
  padding: 0 0 32px 30px;
}

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

.page-about .tl__dot {
  position: absolute;
  left: 0;
  top: 5px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  border: 1px solid var(--neon);
  background: var(--ink);
  transition: background 0.24s var(--ease), box-shadow 0.24s var(--ease);
}

.page-about .tl__item:hover .tl__dot,
.page-about .tl__item:focus-within .tl__dot {
  background: var(--neon);
  box-shadow: 0 0 0 5px rgba(47, 227, 192, 0.14);
}

.page-about .tl__year {
  display: inline-block;
  margin-bottom: 10px;
  padding: 2px 9px;
  border: 1px solid rgba(255, 154, 60, 0.36);
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.12em;
  color: var(--orange);
}

.page-about .tl__title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-size: clamp(19px, 2.2vw, 23px);
  font-weight: 700;
  line-height: 1.4;
  color: var(--white);
}

.page-about .tl__text {
  margin: 0;
  max-width: 62ch;
  font-size: 15.5px;
  line-height: 1.76;
  color: var(--about-soft);
}

.page-about .tl__more {
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  transition: max-height 0.42s var(--ease), opacity 0.28s var(--ease), margin-top 0.42s var(--ease);
}

.page-about .tl__item:hover .tl__more,
.page-about .tl__item:focus-within .tl__more {
  max-height: 340px;
  margin-top: 10px;
  opacity: 1;
}

.page-about .tl__more p {
  margin: 0;
  padding-left: 14px;
  max-width: 60ch;
  border-left: 2px solid var(--orange);
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--muted);
}

/* ---------- 团队三地 ---------- */
.page-about .site-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin-top: 22px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .site-card {
  background: var(--ink-2);
  padding: 22px 20px;
}

.page-about .site-card__coord {
  display: inline-block;
  padding: 2px 9px;
  border: 1px solid rgba(47, 227, 192, 0.35);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--neon);
}

.page-about .site-card__title {
  margin: 12px 0 10px;
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 700;
  line-height: 1.35;
  color: var(--white);
}

.page-about .site-card p {
  margin: 0;
  font-size: 15px;
  line-height: 1.76;
  color: var(--about-soft);
}

/* ---------- 全宽引述 ---------- */
.page-about .about-quote {
  position: relative;
  overflow: hidden;
  margin: 0;
  padding: clamp(34px, 5vw, 62px) 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-quote::before {
  content: "";
  position: absolute;
  left: -6%;
  top: 50%;
  width: clamp(240px, 48%, 560px);
  aspect-ratio: 2 / 1;
  transform: translateY(-50%);
  border-radius: 50%;
  border: 1px solid rgba(75, 107, 255, 0.16);
  background: radial-gradient(ellipse at center, rgba(75, 107, 255, 0.20) 0%, transparent 70%);
  pointer-events: none;
}

.page-about .about-quote p {
  position: relative;
  margin: 0;
  max-width: 26ch;
  font-family: var(--font-display);
  font-size: clamp(21px, 3.4vw, 34px);
  font-weight: 700;
  line-height: 1.5;
  color: var(--white);
}

/* ---------- 内容库列表 ---------- */
.page-about .lib-list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .lib-item {
  display: grid;
  grid-template-columns: 1fr;
  gap: 6px;
  padding: 18px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .lib-item__k {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--neon);
}

.page-about .lib-item p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.76;
  color: var(--about-soft);
}

/* ---------- 适配步骤 ---------- */
.page-about .steps {
  list-style: none;
  margin: 8px 0 0;
  padding: 0;
}

.page-about .steps__item {
  display: grid;
  grid-template-columns: 38px minmax(0, 1fr);
  gap: 16px;
  padding: 18px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .steps__item:first-child {
  border-top: 1px solid var(--line);
}

.page-about .steps__num {
  font-family: var(--font-mono);
  font-size: 16px;
  font-weight: 600;
  line-height: 1.65;
  letter-spacing: 0.06em;
  color: var(--neon);
}

.page-about .steps__title {
  margin: 0 0 6px;
  font-family: var(--font-sans);
  font-size: 16.5px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--white);
}

.page-about .steps__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.76;
  color: var(--about-soft-2);
}

/* ---------- 资质卡片 ---------- */
.page-about .cert-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin-top: 22px;
}

.page-about .cert-card {
  padding: 20px 18px 22px;
  border: 1px solid var(--line);
  background: linear-gradient(180deg, var(--ink-2) 0%, rgba(12, 21, 51, 0.4) 100%);
}

.page-about .cert-card__no {
  display: block;
  margin-bottom: 12px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.16em;
  color: var(--muted);
}

.page-about .cert-card h3 {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--white);
}

.page-about .cert-card p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.74;
  color: var(--about-soft-2);
}

/* ---------- 结尾行动区 ---------- */
.page-about .about-cta {
  padding: clamp(40px, 6vw, 76px) 0;
  border-top: 1px solid var(--line);
  background:
    radial-gradient(90% 140% at 12% 0%, rgba(47, 227, 192, 0.10) 0%, transparent 58%),
    var(--ink-2);
}

.page-about .about-cta .display-2 {
  margin: 0 0 16px;
}

.page-about .about-cta__links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

/* ---------- 平板 ---------- */
@media (min-width: 720px) {
  .page-about .about-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    max-width: 880px;
  }

  .page-about .work-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .lib-item {
    grid-template-columns: 148px minmax(0, 1fr);
    gap: 6px 20px;
    align-items: start;
  }
}

@media (min-width: 820px) {
  .page-about .site-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .cert-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

/* ---------- 桌面：非对称编辑部长文节奏 ---------- */
@media (min-width: 980px) {
  .page-about .about-grid {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    column-gap: var(--about-gap);
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--header-h) + 24px);
    align-self: start;
    padding: 10px 20px 10px 0;
    border-bottom: 0;
    border-right: 1px solid var(--line);
  }

  .page-about .about-rail__list {
    display: block;
  }

  .page-about .about-rail__link {
    display: flex;
    padding: 8px 0 8px 14px;
    border-left: 1px solid var(--line);
  }

  .page-about .about-rail__link:hover,
  .page-about .about-rail__link:focus-visible {
    color: var(--white);
  }

  .page-about .about-rail__link.is-active {
    color: var(--neon);
    border-left-color: var(--neon);
  }

  .page-about .about-rail__link.is-active .about-rail__num {
    color: var(--neon);
  }
}

/* ---------- 触屏与降级 ---------- */
@media (hover: none) {
  .page-about .tl__more {
    max-height: none;
    margin-top: 10px;
    opacity: 1;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .work-card::after,
  .page-about .tl__dot,
  .page-about .tl__more,
  .page-about .about-rail__link {
    transition: none;
  }
}
<<<END>>>