.page-about {
  --about-rail: 214px;
  --bar-h: 60px;
  position: relative;
  background: var(--bg);
  color: var(--snow);
  padding-block: clamp(22px, 3.4vw, 44px) clamp(64px, 9vw, 118px);
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumb {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: clamp(18px, 2.8vw, 34px);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--index);
}
.page-about .breadcrumb a {
  color: var(--cyan);
  text-decoration: none;
  transition: color .2s var(--ease);
}
.page-about .breadcrumb a:hover { color: var(--orange); }
.page-about .breadcrumb__sep { color: var(--line); }
.page-about .breadcrumb__now { color: var(--snow); }

/* ---------- 框景首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(26px, 4.4vw, 64px) clamp(18px, 3.6vw, 56px) clamp(22px, 3.4vw, 48px);
  border: 1px solid var(--line);
  background:
    radial-gradient(120% 140% at 6% -14%, rgba(41, 168, 191, .18), transparent 54%),
    linear-gradient(-92deg, rgba(255, 90, 31, .13), transparent 44%),
    var(--panel);
}
.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 52px 52px;
  opacity: .22;
  -webkit-mask-image: linear-gradient(180deg, rgba(0, 0, 0, .95), transparent 70%);
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, .95), transparent 70%);
}
.page-about .about-hero__inner { position: relative; z-index: 1; }
.page-about .about-hero__eyebrow {
  margin: 0;
  color: var(--cyan);
  letter-spacing: .2em;
}
.page-about .about-hero__title {
  margin: 14px 0 0;
  max-width: 17em;
  font-weight: 200;
  font-size: clamp(31px, 6.1vw, 84px);
  line-height: 1.06;
  letter-spacing: -.02em;
  color: var(--snow);
}
.page-about .hl { color: var(--orange); }
.page-about .about-hero__lede {
  margin: clamp(18px, 2.6vw, 30px) 0 0;
  max-width: 56ch;
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.78;
  color: rgba(233, 239, 244, .84);
}
.page-about .about-hero__stats {
  position: relative;
  z-index: 1;
  list-style: none;
  margin: clamp(26px, 3.6vw, 46px) 0 0;
  padding: clamp(18px, 2.6vw, 26px) 0 0;
  border-top: 1px solid var(--line);
  display: grid;
  gap: 18px 22px;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
}
.page-about .about-stat { display: block; }
.page-about .about-stat__num {
  display: block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(26px, 3.4vw, 38px);
  line-height: 1;
  color: var(--orange);
  letter-spacing: -.01em;
}
.page-about .about-stat__label {
  display: block;
  margin-top: 8px;
  font-size: 12.5px;
  line-height: 1.5;
  color: var(--index);
}

/* ---------- 目录 + 章节 双栏骨架 ---------- */
.page-about .about-layout {
  margin-top: clamp(34px, 5vw, 72px);
  display: grid;
  gap: clamp(26px, 4vw, 54px);
  grid-template-columns: minmax(0, 1fr);
}
.page-about .about-toc {
  border-bottom: 1px solid var(--line);
  padding-bottom: 10px;
}
.page-about .about-toc__title {
  margin: 0 0 10px;
  color: var(--index);
}
.page-about .toc__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: 6px;
  overflow-x: auto;
  scrollbar-width: none;
}
.page-about .toc__list::-webkit-scrollbar { display: none; }
.page-about .toc__link {
  display: inline-flex;
  align-items: baseline;
  gap: 7px;
  padding: 8px 10px;
  white-space: nowrap;
  border-bottom: 2px solid transparent;
  font-size: 13px;
  line-height: 1.4;
  color: var(--index);
  text-decoration: none;
  transition: color .2s var(--ease), border-color .2s var(--ease), background-color .2s var(--ease);
}
.page-about .toc__n {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: .12em;
  color: var(--cyan);
}
.page-about .toc__link:hover { color: var(--snow); background: rgba(41, 168, 191, .1); }
.page-about .toc__link.is-active,
.page-about .toc__link[aria-current] {
  color: var(--snow);
  border-bottom-color: var(--orange);
  background: rgba(255, 90, 31, .08);
}
.page-about .toc__link.is-active .toc__n,
.page-about .toc__link[aria-current] .toc__n { color: var(--orange); }

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

/* ---------- 章节 ---------- */
.page-about .chapter {
  padding-block: clamp(30px, 4.8vw, 66px);
  border-top: 1px solid var(--line);
}
.page-about .chapter:first-child { border-top: 0; padding-top: 0; }
.page-about .chapter__head {
  display: flex;
  gap: clamp(12px, 1.8vw, 22px);
  align-items: baseline;
  margin-bottom: clamp(16px, 2.4vw, 28px);
}
.page-about .chapter__num {
  flex: none;
  padding-top: .38em;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--orange);
}
.page-about .chapter__title {
  margin: 0;
  font-weight: 300;
  font-size: clamp(21px, 3vw, 33px);
  line-height: 1.26;
  letter-spacing: -.01em;
  color: var(--snow);
}
.page-about .chapter__body {
  display: grid;
  gap: clamp(16px, 2vw, 24px);
  max-width: 740px;
}
.page-about .chapter__body p {
  margin: 0;
  font-size: 16px;
  line-height: 1.8;
  color: rgba(233, 239, 244, .82);
}
.page-about .chapter__act {
  margin-top: 4px;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* ---------- 数字条 ---------- */
.page-about .factline {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  grid-template-columns: repeat(auto-fit, minmax(132px, 1fr));
}
.page-about .factline li {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 14px 16px;
  background: var(--panel);
  font-size: 12.5px;
  line-height: 1.5;
  color: var(--index);
}
.page-about .factline b {
  font-family: var(--font-mono);
  font-size: 21px;
  font-weight: 700;
  line-height: 1;
  color: var(--orange);
}

/* ---------- 媒体 ---------- */
.page-about .media {
  position: relative;
  margin: 0;
  overflow: hidden;
  border: 1px solid var(--line);
  background: var(--panel);
}
.page-about .media img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
}
.page-about .media__caption {
  padding: 10px 14px;
  border-top: 1px solid var(--line);
  font-size: 12px;
  line-height: 1.6;
  color: var(--index);
  background: rgba(19, 27, 35, .92);
}
.page-about .media--square { max-width: 520px; }
.page-about .media--tall {
  background: linear-gradient(120deg, rgba(41, 168, 191, .16), rgba(255, 90, 31, .16)), var(--panel);
}

/* ---------- 团队分工 ---------- */
.page-about .roster {
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}
.page-about .roster__item {
  display: grid;
  gap: 8px;
  padding: clamp(18px, 2.4vw, 26px);
  background: var(--panel);
}
.page-about .roster__num {
  font-family: var(--font-mono);
  font-size: clamp(28px, 3.4vw, 40px);
  font-weight: 700;
  line-height: 1;
  color: var(--snow);
}
.page-about .roster__num span {
  margin-left: 5px;
  font-family: var(--font-sans);
  font-size: 12px;
  font-weight: 400;
  color: var(--index);
}
.page-about .roster__role {
  font-size: 13px;
  letter-spacing: .14em;
  color: var(--cyan);
}
.page-about .roster__desc {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--index);
}

/* ---------- 流程 ---------- */
.page-about .flow {
  display: grid;
  gap: 10px;
  grid-template-columns: repeat(auto-fit, minmax(134px, 1fr));
  align-items: start;
}
.page-about .flow__step {
  padding: 16px 14px;
  border: 1px solid var(--line);
  background: var(--panel);
  transition: border-color .22s var(--ease), background-color .22s var(--ease);
}
.page-about .flow__step[open] {
  border-color: rgba(255, 90, 31, .5);
  background: linear-gradient(160deg, rgba(255, 90, 31, .09), transparent 70%), var(--panel);
}
.page-about .flow__step summary {
  display: grid;
  gap: 10px;
  justify-items: start;
  list-style: none;
  cursor: pointer;
}
.page-about .flow__step summary::-webkit-details-marker { display: none; }
.page-about .flow__box {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .06em;
  color: var(--cyan);
  background: linear-gradient(140deg, rgba(41, 168, 191, .2), transparent);
  transition: color .22s var(--ease), border-color .22s var(--ease);
}
.page-about .flow__step[open] .flow__box {
  color: var(--orange);
  border-color: var(--orange);
  background: linear-gradient(140deg, rgba(255, 90, 31, .26), transparent);
}
.page-about .flow__name {
  font-size: 14px;
  letter-spacing: .08em;
  color: var(--snow);
}
.page-about .flow__duty {
  margin: 12px 0 0;
  font-size: 13px;
  line-height: 1.68;
  color: var(--index);
}

/* ---------- 版本里程碑 ---------- */
.page-about .mile {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0;
}
.page-about .mile::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 12px;
  bottom: 14px;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan), var(--orange));
  opacity: .55;
}
.page-about .mile__item {
  position: relative;
  padding: 0 0 clamp(22px, 3vw, 32px) 30px;
}
.page-about .mile__item:last-child { padding-bottom: 0; }
.page-about .mile__dot {
  position: absolute;
  left: 0;
  top: 5px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  border: 1px solid var(--cyan);
  background: var(--bg);
}
.page-about .mile__item--now .mile__dot {
  border-color: var(--orange);
  background: var(--orange);
  box-shadow: 0 0 0 4px rgba(255, 90, 31, .18);
}
.page-about .mile__stage {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: .18em;
  color: var(--index);
}
.page-about .mile__item--now .mile__stage { color: var(--lime); }
.page-about .mile__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.76;
  color: rgba(233, 239, 244, .82);
}

/* ---------- 状态标签 ---------- */
.page-about .tagsrow {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.page-about .tagsrow .tag {
  padding: 5px 11px;
  border: 1px solid var(--line);
  background: var(--panel);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--index);
}
.page-about .tagsrow .tag:first-child { color: var(--cyan); border-color: rgba(41, 168, 191, .45); }
.page-about .tagsrow .tag:nth-child(2) {
  color: var(--ink);
  background: var(--lime);
  border-color: var(--lime);
}

/* ---------- 联系方式 ---------- */
.page-about .contactlist {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}
.page-about .contactlist li {
  display: grid;
  grid-template-columns: 74px minmax(0, 1fr);
  gap: 12px;
  align-items: baseline;
  padding: 14px 16px;
  background: var(--panel);
  font-size: 14px;
  line-height: 1.6;
  color: var(--snow);
  word-break: break-word;
}
.page-about .contactlist__k {
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--index);
}
.page-about .contactlist a {
  color: var(--cyan);
  text-decoration: none;
  transition: color .2s var(--ease);
}
.page-about .contactlist a:hover { color: var(--orange); }

/* ---------- 后续入口 ---------- */
.page-about .about-next {
  margin-top: clamp(44px, 6vw, 86px);
  padding-top: clamp(26px, 3.6vw, 46px);
  border-top: 1px solid var(--line);
}
.page-about .about-next .eyebrow { color: var(--index); }
.page-about .about-next__title {
  margin: 12px 0 0;
  font-weight: 300;
  font-size: clamp(21px, 2.8vw, 30px);
  line-height: 1.3;
  color: var(--snow);
}
.page-about .nextlinks {
  list-style: none;
  margin: clamp(18px, 2.6vw, 30px) 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}
.page-about .nextlinks li {
  display: grid;
  gap: 6px;
  padding: 18px;
  background: var(--panel);
  transition: background-color .22s var(--ease);
}
.page-about .nextlinks li:hover { background: #17222C; }
.page-about .nextlinks a {
  font-size: 15px;
  letter-spacing: .04em;
  color: var(--cyan);
  text-decoration: none;
  transition: color .2s var(--ease);
}
.page-about .nextlinks a:hover { color: var(--orange); }
.page-about .nextlinks p {
  margin: 0;
  font-size: 13px;
  line-height: 1.68;
  color: var(--index);
}

/* ---------- 桌面：左侧常驻索引 ---------- */
@media (min-width: 1024px) {
  .page-about .about-layout {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: clamp(36px, 4.4vw, 82px);
    align-items: start;
  }
  .page-about .about-toc {
    position: sticky;
    top: 32px;
    border-bottom: 0;
    border-top: 1px solid var(--line);
    padding: 16px 0 0;
    max-height: calc(100vh - 64px);
    overflow-y: auto;
  }
  .page-about .about-toc__title { margin-bottom: 14px; }
  .page-about .toc__list {
    display: grid;
    gap: 0;
    overflow: visible;
  }
  .page-about .toc__link {
    display: grid;
    grid-template-columns: 24px minmax(0, 1fr);
    align-items: baseline;
    gap: 8px;
    white-space: normal;
    padding: 9px 10px;
    border-bottom: 0;
    border-left: 2px solid transparent;
  }
  .page-about .toc__link.is-active,
  .page-about .toc__link[aria-current] {
    border-left-color: var(--orange);
    border-bottom-color: transparent;
  }
  .page-about .roster { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .page-about .about-next__title { max-width: 22em; }
  .page-about .nextlinks { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (min-width: 1320px) {
  .page-about .chapter__body { max-width: 780px; }
  .page-about .nextlinks { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .toc__link,
  .page-about .flow__step,
  .page-about .flow__box,
  .page-about .nextlinks li,
  .page-about .contactlist a {
    transition: none;
  }
}
<<<END>>>