.page-about {
  --about-rail-w: 196px;
  --about-line: rgba(126, 148, 166, 0.34);
  --about-line-soft: rgba(126, 148, 166, 0.2);
  --about-body-text: rgba(232, 241, 234, 0.86);
  --about-dim-text: rgba(232, 241, 234, 0.74);
  --about-ink-soft: #4a3f36;
  background: var(--ink);
  color: var(--mist);
  padding-top: calc(var(--header-offset) + 12px);
  overflow-x: clip;
  font-family: var(--font-body);
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumb {
  padding-block: 8px 4px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding-block: 12px 0;
}

.page-about .about-hero__ghost {
  position: absolute;
  top: -18px;
  right: 4vw;
  font-size: clamp(90px, 22vw, 220px);
  font-weight: 700;
  letter-spacing: -0.04em;
  color: var(--lime);
  opacity: 0.07;
  line-height: 1;
  pointer-events: none;
  user-select: none;
}

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

.page-about .about-hero__title {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(36px, 9.2vw, 84px);
  line-height: 0.98;
  letter-spacing: -0.02em;
  margin: 14px 0 20px;
  color: var(--mist);
  max-width: 15ch;
}

.page-about .about-hero__lead {
  max-width: 60ch;
  font-size: var(--fs-base);
  line-height: 1.8;
  color: var(--about-body-text);
  margin: 0 0 26px;
  border-left: 3px solid var(--lime);
  padding-left: 16px;
}

.page-about .about-hero__nums {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}

.page-about .about-hero__nums > li {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--about-line-soft);
}

.page-about .about-hero__num {
  font-family: var(--font-mono);
  font-size: clamp(26px, 6vw, 38px);
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--lime);
  line-height: 1;
  font-variant-numeric: tabular-nums;
  min-width: 3.4em;
}

.page-about .about-hero__unit {
  font-size: 0.5em;
  color: var(--orange);
  margin-left: 2px;
}

.page-about .about-hero__cap {
  font-size: 13px;
  line-height: 1.5;
  color: var(--about-dim-text);
}

.page-about .about-hero__media {
  margin: 24px 0 0;
}

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

.page-about .about-rule {
  height: 5px;
  margin: 26px 0 0;
  background: linear-gradient(90deg, transparent, var(--lime) 16%, var(--orange) 64%, transparent);
  transform: rotate(-0.5deg);
  opacity: 0.7;
}

/* ---------- 双栏骨架 ---------- */
.page-about .about-layout {
  display: grid;
  grid-template-columns: 1fr;
  padding-block: 32px 64px;
}

.page-about .about-rail {
  display: none;
}

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

/* ---------- 章节 ---------- */
.page-about .about-chapter {
  padding-block: 30px 34px;
  border-top: 1px solid var(--about-line-soft);
  scroll-margin-top: calc(var(--header-offset) + 16px);
}

.page-about .about-chapter:first-child {
  border-top: 0;
  padding-top: 6px;
}

.page-about .about-chapter__head {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  margin-bottom: 16px;
}

.page-about .about-chapter__num {
  font-family: var(--font-mono);
  font-size: clamp(28px, 6vw, 42px);
  font-weight: 700;
  line-height: 0.9;
  color: var(--lime);
  opacity: 0.38;
  flex: none;
  font-variant-numeric: tabular-nums;
}

.page-about .about-chapter__title {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(23px, 4.6vw, 36px);
  line-height: 1.1;
  letter-spacing: -0.01em;
  margin: 0;
  color: var(--mist);
}

.page-about .about-chapter__body p {
  max-width: 64ch;
  font-size: var(--fs-base);
  line-height: 1.8;
  color: var(--about-body-text);
  margin: 0 0 14px;
}

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

/* ---------- 奶油纸数据条 ---------- */
.page-about .about-stats {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
  margin-top: 22px;
}

.page-about .about-stat {
  background: var(--cream);
  color: var(--brown);
  padding: 14px 16px 15px;
  border-left: 3px solid var(--orange-deep);
  border-radius: 0 var(--radius) var(--radius) 0;
  clip-path: polygon(0 0, calc(100% - var(--cut)) 0, 100% var(--cut), 100% 100%, 0 100%);
  transition: transform 180ms ease, border-color 180ms ease;
}

.page-about .about-stat:hover {
  transform: translateY(-2px);
  border-left-color: var(--orange);
}

.page-about .about-stat__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 26px;
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.1;
  font-variant-numeric: tabular-nums;
}

.page-about .about-stat__unit {
  font-size: 0.55em;
  color: var(--orange-deep);
  margin-left: 2px;
}

.page-about .about-stat__label {
  display: block;
  margin-top: 4px;
  font-size: 13px;
  line-height: 1.55;
  color: var(--about-ink-soft);
}

/* ---------- 七类内容 ---------- */
.page-about .about-kinds {
  list-style: none;
  margin: 20px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
}

.page-about .about-kind {
  background: var(--panel);
  border: 1px solid var(--about-line);
  border-radius: var(--radius);
  padding: 15px 16px 16px;
  transition: border-color 180ms ease, transform 180ms ease;
}

.page-about .about-kind:hover {
  border-color: var(--lime);
  transform: translateY(-2px);
}

.page-about .about-kind--lead {
  border-color: var(--lime);
  background: linear-gradient(150deg, rgba(200, 242, 75, 0.1), var(--panel) 62%);
}

.page-about .about-kind__idx {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--lime);
  letter-spacing: 0.06em;
}

.page-about .about-kind__title {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 21px;
  line-height: 1.2;
  margin: 4px 0 6px;
  color: var(--mist);
}

.page-about .about-kind__desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.68;
  color: var(--about-dim-text);
}

/* ---------- 流程 ---------- */
.page-about .about-split {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
  align-items: start;
}

.page-about .about-steps {
  list-style: none;
  margin: 18px 0 0;
  padding: 0;
}

.page-about .about-step {
  display: grid;
  grid-template-columns: 26px 1fr;
  gap: 14px;
  padding: 13px 0;
  border-bottom: 1px dashed var(--about-line);
}

.page-about .about-step:last-child {
  border-bottom: 0;
}

.page-about .about-step__num {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  width: 26px;
  height: 26px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: var(--lime);
  color: var(--ink);
  margin-top: 2px;
  font-variant-numeric: tabular-nums;
}

.page-about .about-step__title {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 19px;
  line-height: 1.3;
  margin: 0 0 4px;
  color: var(--mist);
}

.page-about .about-step__desc {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--about-dim-text);
}

.page-about .about-process__media,
.page-about .about-coverage__media {
  margin: 0;
}

.page-about .about-coverage__media {
  margin-top: 24px;
}

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

/* ---------- 阶段日志 ---------- */
.page-about .about-log {
  list-style: none;
  margin: 8px 0 0;
  padding: 0;
}

.page-about .about-log__row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 6px;
  padding: 16px 0;
  border-bottom: 1px solid var(--about-line-soft);
}

.page-about .about-log__row:last-child {
  border-bottom: 0;
}

.page-about .about-log__year {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--lime);
  font-variant-numeric: tabular-nums;
}

.page-about .about-log__title {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 20px;
  line-height: 1.25;
  margin: 0 0 5px;
  color: var(--mist);
}

.page-about .about-log__desc {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--about-dim-text);
  max-width: 56ch;
}

.page-about .about-log__bar {
  justify-self: start;
  display: inline-block;
  margin-top: 8px;
  padding: 3px 9px;
  font-family: var(--font-mono);
  font-size: 12px;
  background: var(--cream);
  color: var(--brown);
  border-radius: 2px;
  white-space: nowrap;
}

/* ---------- 继续了解 ---------- */
.page-about .about-next {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
  margin-top: 18px;
}

.page-about .about-next__card {
  position: relative;
  display: block;
  text-decoration: none;
  color: var(--mist);
  background: var(--panel);
  border: 1px solid var(--about-line);
  border-radius: var(--radius);
  padding: 18px 18px 20px;
  transition: border-color 180ms ease, transform 180ms ease;
}

.page-about .about-next__card:hover,
.page-about .about-next__card:focus-visible {
  border-color: var(--lime);
  transform: translateY(-2px);
}

.page-about .about-next__tag {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--orange);
}

.page-about .about-next__title {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 22px;
  line-height: 1.2;
  margin: 6px 0 6px;
  color: var(--mist);
}

.page-about .about-next__desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.68;
  color: var(--about-dim-text);
  padding-right: 24px;
}

.page-about .about-next__arrow {
  position: absolute;
  right: 16px;
  bottom: 16px;
  font-family: var(--font-mono);
  color: var(--lime);
  transition: transform 180ms ease;
}

.page-about .about-next__card:hover .about-next__arrow {
  transform: translateX(4px);
}

.page-about .about-inline-link {
  margin: 20px 0 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--about-dim-text);
  max-width: 64ch;
}

.page-about .about-inline-link a {
  color: var(--lime);
}

.page-about .about-inline-link a:hover {
  color: var(--orange);
}

.page-about .about-chapter--last {
  padding-bottom: 8px;
}

/* ---------- 640px ---------- */
@media (min-width: 640px) {
  .page-about .about-hero__nums {
    grid-template-columns: repeat(3, 1fr);
    gap: 18px;
  }

  .page-about .about-hero__nums > li {
    display: block;
    border-bottom: 0;
    border-left: 1px solid var(--about-line-soft);
    padding: 0 0 0 14px;
  }

  .page-about .about-hero__num {
    display: block;
    margin-bottom: 6px;
  }

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

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

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

/* ---------- 768px ---------- */
@media (min-width: 768px) {
  .page-about .about-split {
    grid-template-columns: 1.08fr 0.92fr;
    gap: 32px;
  }

  .page-about .about-process__media {
    position: sticky;
    top: calc(var(--header-offset) + 24px);
  }

  .page-about .about-log__row {
    grid-template-columns: 118px 1fr;
    column-gap: 22px;
    align-items: start;
  }

  .page-about .about-log__year {
    padding-top: 4px;
  }

  .page-about .about-log__bar {
    grid-column: 2;
    margin-top: 9px;
  }
}

/* ---------- 1120px：左侧黏性章节轴 ---------- */
@media (min-width: 1120px) {
  .page-about .about-crumb {
    padding-block: 16px 4px;
  }

  .page-about .about-hero__title {
    margin-top: 18px;
  }

  .page-about .about-layout {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    column-gap: 48px;
    padding-block: 44px 88px;
  }

  .page-about .about-rail {
    display: block;
    position: sticky;
    top: calc(var(--header-offset) + 28px);
    align-self: start;
  }

  .page-about .about-rail__list {
    position: relative;
    list-style: none;
    margin: 0;
    padding: 0 0 0 20px;
  }

  .page-about .about-rail__list::before {
    content: "";
    position: absolute;
    left: 3px;
    top: 14px;
    bottom: 14px;
    width: 1px;
    background: var(--about-line);
  }

  .page-about .about-rail__node {
    position: relative;
    display: block;
    padding: 8px 0;
    font-size: 14px;
    line-height: 1.5;
    color: var(--steel);
    text-decoration: none;
    transition: color 180ms ease;
  }

  .page-about .about-rail__node::before {
    content: "";
    position: absolute;
    left: -21px;
    top: 15px;
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--ink);
    border: 1px solid var(--steel);
    transition: background 180ms ease, border-color 180ms ease, box-shadow 180ms ease;
  }

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

  .page-about .about-rail__node:hover::before,
  .page-about .about-rail__node:focus-visible::before {
    background: var(--lime);
    border-color: var(--lime);
    box-shadow: 0 0 0 4px rgba(200, 242, 75, 0.18);
  }

  .page-about .about-chapter {
    padding-block: 40px 48px;
  }

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

  .page-about .about-kind--lead {
    grid-column: span 2;
  }

  .page-about .about-chapter__head {
    gap: 18px;
  }
}

/* ---------- 1440px ---------- */
@media (min-width: 1440px) {
  .page-about .about-layout {
    column-gap: 64px;
  }

  .page-about .about-hero__lead {
    font-size: 18px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-stat,
  .page-about .about-kind,
  .page-about .about-next__card,
  .page-about .about-next__arrow,
  .page-about .about-rail__node,
  .page-about .about-rail__node::before {
    transition: none;
  }
}
<<<END>>>