.page-about {
  --about-rail-w: 208px;
  --about-col-gap: clamp(1.8rem, 4.5vw, 4.5rem);
  --about-chapter-gap: clamp(3.4rem, 7vw, 6rem);
}

.page-about .about-crumbs {
  padding-top: 1.4rem;
}

/* ---------- 主体两栏骨架 ---------- */
.page-about .about-main__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 2rem;
}

.page-about .about-col {
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: var(--about-chapter-gap);
}

/* ---------- 左侧阅读刻度 ---------- */
.page-about .about-rail__kicker {
  margin: 0 0 .7rem;
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--mist);
}

.page-about .about-rail__list {
  display: flex;
  gap: .35rem;
  margin: 0;
  padding: 0 0 .35rem;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
}

.page-about .about-rail__list::-webkit-scrollbar {
  display: none;
}

.page-about .about-rail__link {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  padding: .42rem .8rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--mist);
  font-size: .78rem;
  white-space: nowrap;
  text-decoration: none;
  transition: color var(--t-fast) var(--ease), border-color var(--t-fast) var(--ease), background var(--t-fast) var(--ease);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  color: var(--paper);
  border-color: var(--line-strong);
}

.page-about .about-rail__link.is-active {
  color: var(--ink-900);
  background: var(--jade);
  border-color: var(--jade);
}

.page-about .about-rail__tick {
  font-size: .7rem;
  letter-spacing: .1em;
  opacity: .85;
}

/* ---------- 章节通用 ---------- */
.page-about .about-chapter {
  scroll-margin-top: 6.5rem;
}

.page-about .about-chapter__head {
  max-width: 64ch;
}

.page-about .about-chapter__head h1 {
  margin: .7rem 0 0;
  font-size: clamp(1.75rem, 4.6vw, 3.1rem);
  line-height: 1.18;
  letter-spacing: .02em;
  color: var(--paper);
}

.page-about .about-chapter__head h2 {
  margin: .7rem 0 0;
  font-size: clamp(1.4rem, 3.2vw, 2.15rem);
  line-height: 1.24;
  letter-spacing: .03em;
  color: var(--paper);
}

.page-about .about-chapter__head .lede {
  margin: 1.1rem 0 0;
  color: var(--mist);
  font-size: 1.02rem;
  line-height: 1.85;
  max-width: 62ch;
}

.page-about .about-chapter__figure {
  margin: clamp(1.6rem, 3.4vw, 2.6rem) 0 0;
}

.page-about .about-chapter__figure--bleed {
  margin-inline: clamp(-1rem, -1.5vw, -.5rem);
}

.page-about .about-chapter__prose {
  margin-top: clamp(1.4rem, 2.8vw, 2.2rem);
  color: var(--mist);
  max-width: 68ch;
}

.page-about .about-chapter__prose p {
  margin: 0 0 1.05rem;
  line-height: 1.85;
}

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

.page-about .about-chapter__note {
  margin: clamp(1.6rem, 3vw, 2.4rem) 0 0;
  padding-left: 1.1rem;
  border-left: 2px solid var(--jade);
  color: var(--mist);
  font-size: .96rem;
  line-height: 1.85;
  max-width: 66ch;
}

/* ---------- 三条业务线 ---------- */
.page-about .about-lines {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1rem;
  margin-top: clamp(1.6rem, 3vw, 2.6rem);
}

.page-about .about-line {
  position: relative;
  padding: 1.5rem 1.35rem 1.6rem;
  border: 1px solid var(--line);
  border-radius: var(--r-m);
  background: linear-gradient(180deg, rgba(20, 38, 63, .78) 0%, rgba(10, 21, 36, .9) 100%);
  overflow: hidden;
}

.page-about .about-line::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 3px;
  background: var(--accent, var(--jade));
}

.page-about .about-line--jade { --accent: var(--jade); }
.page-about .about-line--gold { --accent: var(--gold); }
.page-about .about-line--violet { --accent: var(--violet); }

.page-about .about-line h3 {
  margin: 1rem 0 .7rem;
  font-size: 1.16rem;
  letter-spacing: .03em;
  color: var(--paper);
}

.page-about .about-line p {
  margin: 0;
  color: var(--mist);
  font-size: .95rem;
  line-height: 1.8;
}

.page-about .about-line__list {
  margin: 1.05rem 0 0;
  padding: 0;
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: .45rem;
}

.page-about .about-line__list li {
  position: relative;
  padding-left: .95rem;
  font-size: .84rem;
  line-height: 1.6;
  color: var(--paper);
  opacity: .82;
}

.page-about .about-line__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .58em;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--accent, var(--jade));
}

/* ---------- 规模数字 ---------- */
.page-about .about-scale {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1.2rem;
  margin-top: clamp(1.8rem, 3.4vw, 2.8rem);
}

.page-about .about-scale__item {
  padding: 1.3rem 1.2rem 1.4rem;
  border: 1px dashed var(--line-strong);
  border-radius: var(--r-m);
  background: rgba(20, 38, 63, .4);
}

.page-about .about-scale__num {
  display: block;
  font-size: clamp(3rem, 11vw, 5.2rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.02em;
  color: transparent;
  -webkit-text-stroke: 1.6px var(--jade);
}

.page-about .about-scale__num--gold { -webkit-text-stroke-color: var(--gold); }
.page-about .about-scale__num--violet { -webkit-text-stroke-color: var(--violet); }

.page-about .about-scale__unit {
  display: block;
  margin-top: .6rem;
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--mist);
}

.page-about .about-scale__item p {
  margin: .75rem 0 0;
  color: var(--mist);
  font-size: .88rem;
  line-height: 1.75;
}

/* ---------- 三个分类维度 ---------- */
.page-about .about-dims {
  margin-top: clamp(1.6rem, 3vw, 2.4rem);
  border-top: 1px solid var(--line);
}

.page-about .about-dims__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: .5rem;
  padding: 1.05rem 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-dims__key {
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--jade-soft);
}

.page-about .about-dims__row p {
  margin: 0;
  color: var(--mist);
  font-size: .94rem;
  line-height: 1.8;
}

/* ---------- 班次 ---------- */
.page-about .about-shifts {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: .9rem;
  margin-top: clamp(1.6rem, 3vw, 2.4rem);
}

.page-about .about-shift {
  padding: 1.35rem 1.25rem 1.45rem;
  border: 1px solid var(--line);
  border-left: 3px solid var(--ink-700);
  border-radius: var(--r-s);
  background: rgba(20, 38, 63, .5);
}

.page-about .about-shift--mid {
  border-left-color: var(--amber);
  background: rgba(240, 169, 59, .07);
}

.page-about .about-shift__no {
  display: block;
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--mist);
}

.page-about .about-shift h3 {
  margin: .6rem 0 .55rem;
  font-size: 1.06rem;
  letter-spacing: .03em;
  color: var(--paper);
}

.page-about .about-shift p {
  margin: 0;
  color: var(--mist);
  font-size: .92rem;
  line-height: 1.8;
}

.page-about .about-shift__foot {
  margin-top: clamp(1.4rem, 2.6vw, 2rem);
  padding: 1.2rem 1.3rem;
  border-radius: var(--r-m);
  background: rgba(23, 185, 138, .08);
  border: 1px solid rgba(23, 185, 138, .25);
  max-width: 72ch;
}

.page-about .about-shift__foot p {
  margin: 0;
  color: var(--mist);
  font-size: .92rem;
  line-height: 1.85;
}

.page-about .about-shift__foot a {
  color: var(--jade-soft);
  text-decoration: none;
  border-bottom: 1px solid rgba(111, 227, 192, .4);
}

.page-about .about-shift__foot a:hover,
.page-about .about-shift__foot a:focus-visible {
  color: var(--paper);
  border-bottom-color: var(--paper);
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1rem;
  margin-top: clamp(1.6rem, 3vw, 2.4rem);
}

.page-about .about-team__item {
  padding: 1.3rem 1.25rem 1.4rem;
  border-radius: var(--r-m);
  background: rgba(20, 38, 63, .55);
  border: 1px solid var(--line);
}

.page-about .about-team__idx {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  border: 1px solid var(--line-strong);
  font-size: .74rem;
  color: var(--jade-soft);
}

.page-about .about-team__item h3 {
  margin: .85rem 0 .55rem;
  font-size: 1.02rem;
  letter-spacing: .03em;
  color: var(--paper);
}

.page-about .about-team__item p {
  margin: 0;
  color: var(--mist);
  font-size: .92rem;
  line-height: 1.8;
}

.page-about .about-cadence {
  margin-top: clamp(1.5rem, 2.8vw, 2.2rem);
  padding-top: 1.4rem;
  border-top: 1px dashed var(--line-strong);
}

.page-about .about-cadence__lead {
  margin: 0 0 .9rem;
  font-size: .82rem;
  letter-spacing: .12em;
  color: var(--mist);
}

.page-about .about-cadence__list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: .8rem;
}

.page-about .about-cadence__list li {
  display: grid;
  grid-template-columns: 3.6rem minmax(0, 1fr);
  gap: .8rem;
  align-items: start;
  color: var(--mist);
  font-size: .93rem;
  line-height: 1.8;
}

.page-about .about-cadence__list .mono {
  padding-top: .18rem;
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--gold);
}

/* ---------- 收束 ---------- */
.page-about .about-chapter--closing .lede {
  max-width: 66ch;
}

.page-about .about-next {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1rem;
  margin-top: clamp(1.6rem, 3vw, 2.4rem);
}

.page-about .about-next__card {
  display: block;
  padding: 1.5rem 1.4rem 1.6rem;
  border-radius: var(--r-l);
  border: 1px solid var(--line);
  background: linear-gradient(160deg, rgba(23, 185, 138, .12) 0%, rgba(10, 21, 36, .92) 62%);
  text-decoration: none;
  transition: border-color var(--t-mid) var(--ease), transform var(--t-mid) var(--ease);
}

.page-about .about-next__card:last-child {
  background: linear-gradient(160deg, rgba(124, 92, 255, .14) 0%, rgba(10, 21, 36, .92) 62%);
}

.page-about .about-next__card:hover,
.page-about .about-next__card:focus-visible {
  border-color: var(--line-strong);
  transform: translateY(-3px);
}

.page-about .about-next__tag {
  display: block;
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--mist);
}

.page-about .about-next__card h3 {
  margin: .7rem 0 .6rem;
  font-size: 1.22rem;
  letter-spacing: .04em;
  color: var(--paper);
}

.page-about .about-next__card p {
  margin: 0 0 1.1rem;
  color: var(--mist);
  font-size: .93rem;
  line-height: 1.8;
}

.page-about .about-next__go {
  display: inline-block;
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--jade-soft);
}

.page-about .about-next__card:last-child .about-next__go {
  color: var(--violet-soft);
}

.page-about .about-partner {
  margin-top: clamp(1.8rem, 3.2vw, 2.6rem);
  padding-top: 1.5rem;
  border-top: 1px solid var(--line);
  max-width: 68ch;
}

.page-about .about-partner h3 {
  margin: 0 0 .8rem;
  font-size: 1.06rem;
  letter-spacing: .04em;
  color: var(--paper);
}

.page-about .about-partner p {
  margin: 0 0 .9rem;
  color: var(--mist);
  font-size: .93rem;
  line-height: 1.85;
}

.page-about .about-partner__brand {
  padding-left: 1rem;
  border-left: 2px solid var(--violet);
  color: var(--paper);
  opacity: .86;
}

/* ---------- 底部章节导航 ---------- */
.page-about .about-foot-nav {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: .7rem;
  padding-top: 1.6rem;
  border-top: 1px solid var(--line);
}

.page-about .about-foot-nav__link {
  display: flex;
  align-items: baseline;
  gap: .8rem;
  padding: .9rem 1.1rem;
  border: 1px solid var(--line);
  border-radius: var(--r-s);
  color: var(--paper);
  font-size: .92rem;
  text-decoration: none;
  transition: border-color var(--t-fast) var(--ease), background var(--t-fast) var(--ease);
}

.page-about .about-foot-nav__link:hover,
.page-about .about-foot-nav__link:focus-visible {
  border-color: var(--line-strong);
  background: rgba(20, 38, 63, .6);
}

.page-about .about-foot-nav__link .mono {
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--mist);
}

.page-about .about-foot-nav__link--next {
  justify-content: flex-end;
}

/* ---------- 中等宽度 ---------- */
@media (min-width: 620px) {
  .page-about .about-scale {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-shifts {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-shift--mid {
    grid-column: 1 / -1;
  }

  .page-about .about-team {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-team__item:last-child {
    grid-column: 1 / -1;
  }

  .page-about .about-next {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-foot-nav {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-dims__row {
    grid-template-columns: 6.5rem minmax(0, 1fr);
    gap: 1.4rem;
    align-items: baseline;
  }
}

/* ---------- 桌面：左右分屏 + 左侧刻度常驻 ---------- */
@media (min-width: 1000px) {
  .page-about .about-main__grid {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: var(--about-col-gap);
    align-items: start;
  }

  .page-about .about-rail {
    position: sticky;
    top: 6.5rem;
    align-self: start;
  }

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

  .page-about .about-rail__list::before {
    content: "";
    position: absolute;
    left: 3px;
    top: .6rem;
    bottom: .6rem;
    width: 1px;
    background: linear-gradient(180deg, var(--jade) 0%, var(--violet) 56%, rgba(147, 166, 190, .16) 100%);
    opacity: .55;
  }

  .page-about .about-rail__link {
    position: relative;
    padding: .58rem 0 .58rem 1.35rem;
    border: 0;
    border-radius: 0;
    background: none !important;
    font-size: .84rem;
    color: var(--mist);
  }

  .page-about .about-rail__link::before {
    content: "";
    position: absolute;
    left: 0;
    top: 50%;
    width: 7px;
    height: 7px;
    margin-top: -3.5px;
    border-radius: 50%;
    background: var(--ink-700);
    transition: background var(--t-fast) var(--ease), box-shadow var(--t-fast) var(--ease);
  }

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

  .page-about .about-rail__link.is-active::before {
    background: var(--jade);
    box-shadow: 0 0 0 4px rgba(23, 185, 138, .18);
  }

  .page-about .about-rail__tick {
    display: inline-block;
    min-width: 1.6rem;
  }

  .page-about .about-lines {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1.1rem;
  }

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

  .page-about .about-shift--mid {
    grid-column: auto;
  }

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

  .page-about .about-team__item:last-child {
    grid-column: auto;
  }

  .page-about .about-chapter__figure--bleed {
    margin-inline: calc(-1 * var(--about-col-gap) * .32);
    border-radius: var(--r-l);
    overflow: hidden;
  }
}
<<<END>>>