.page-about {
  --about-rail: 236px;
  background: var(--c-porcelain);
  color: var(--c-ink);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  padding: clamp(36px, 6vw, 76px) 0 clamp(44px, 7vw, 92px);
  background: linear-gradient(158deg, var(--c-ink) 0%, var(--c-deep) 56%, var(--c-indigo) 100%);
  color: var(--c-porcelain);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background-image:
    linear-gradient(90deg, var(--line-faint) 1px, transparent 1px),
    linear-gradient(0deg, var(--line-faint) 1px, transparent 1px);
  background-size: 96px 96px;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  z-index: -1;
  top: -18%;
  right: -8%;
  width: min(58%, 620px);
  aspect-ratio: 1 / 1;
  pointer-events: none;
  background: linear-gradient(200deg, rgba(217, 164, 65, 0.22), rgba(217, 164, 65, 0) 62%);
  clip-path: polygon(100% 0, 100% 100%, 0 100%);
}

.page-about .about-hero__inner {
  display: grid;
  gap: clamp(30px, 5vw, 56px);
}

.page-about .about-hero__plate {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 0 0 22px;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.16em;
  color: var(--c-amber);
}

.page-about .about-hero__plate::before {
  content: "";
  width: 30px;
  height: 1px;
  background: var(--c-amber);
}

.page-about .about-hero h1 {
  margin: 0 0 22px;
  font-family: var(--font-display);
  font-size: clamp(1.9rem, 5vw, 3.4rem);
  font-weight: 900;
  line-height: 1.2;
  letter-spacing: -0.01em;
  max-width: 18ch;
}

.page-about .about-hero__lede {
  margin: 0 0 20px;
  max-width: 46ch;
  font-size: var(--fs-16);
  line-height: 1.85;
  color: rgba(246, 243, 236, 0.8);
}

.page-about .about-hero__claim {
  margin: 0;
  padding-left: 16px;
  border-left: 2px solid var(--c-amber);
  font-family: var(--font-display);
  font-size: var(--fs-18);
  line-height: 1.6;
  color: var(--c-amber-lt);
}

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

.page-about .about-hero__facts li {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 18px 16px;
  background: rgba(14, 27, 44, 0.9);
}

.page-about .about-hero__facts strong {
  font-family: var(--font-mono);
  font-size: clamp(1.4rem, 3.4vw, 1.9rem);
  font-weight: 500;
  color: var(--c-amber-lt);
  line-height: 1;
}

.page-about .about-hero__facts span {
  font-size: var(--fs-12);
  line-height: 1.6;
  letter-spacing: 0.04em;
  color: rgba(246, 243, 236, 0.62);
}

/* ---------- 正文区 ---------- */
.page-about .about-body {
  --about-muted: #56626f;
  --line: rgba(20, 38, 61, 0.12);
  --line-strong: rgba(20, 38, 61, 0.22);
  background: var(--c-porcelain);
  color: var(--c-ink);
  padding: clamp(36px, 6vw, 84px) 0 clamp(56px, 8vw, 112px);
}

.page-about .about-body__inner {
  display: grid;
  gap: clamp(28px, 4vw, 60px);
}

/* ---------- 左侧章节导航 ---------- */
.page-about .about-rail {
  display: none;
}

.page-about .about-rail__label {
  margin: 0 0 14px;
  font-size: var(--fs-12);
  letter-spacing: 0.18em;
  color: var(--about-muted);
}

.page-about .about-rail__list {
  list-style: none;
  margin: 0 0 26px;
  padding: 0;
  display: grid;
  gap: 1px;
}

.page-about .about-rail__link {
  display: flex;
  gap: 10px;
  align-items: baseline;
  padding: 9px 8px 9px 0;
  border-bottom: 1px solid var(--line);
  color: var(--c-ink);
  text-decoration: none;
  font-size: var(--fs-14);
  line-height: 1.5;
  transition: color 200ms var(--ease), padding-left 200ms var(--ease);
}

.page-about .about-rail__link .mono {
  font-size: var(--fs-12);
  color: var(--c-amber);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  color: #8a6116;
  padding-left: 4px;
}

.page-about .about-rail__link:focus-visible {
  outline: 2px solid var(--c-amber);
  outline-offset: 2px;
}

.page-about .about-rail__stamp {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 8px 12px;
  border: 1px solid var(--line-strong);
  background: var(--c-paper);
  color: var(--c-ink);
  text-decoration: none;
  font-size: var(--fs-12);
  letter-spacing: 0.04em;
  clip-path: polygon(0 0, 100% 0, 100% 72%, 72% 100%, 0 100%);
  transition: border-color 200ms var(--ease);
}

.page-about .about-rail__stamp .mono {
  color: #8a6116;
}

.page-about .about-rail__stamp:focus-visible {
  outline: 2px solid var(--c-amber);
  outline-offset: 2px;
}

/* ---------- 章节 ---------- */
.page-about .about-chapter {
  padding-bottom: clamp(32px, 5vw, 60px);
  margin-bottom: clamp(32px, 5vw, 60px);
  border-bottom: 1px solid var(--line-strong);
}

.page-about .about-chapter:last-child {
  padding-bottom: 0;
  margin-bottom: 0;
  border-bottom: 0;
}

.page-about .about-chapter__head {
  display: flex;
  gap: 14px;
  align-items: flex-start;
  margin-bottom: 20px;
}

.page-about .about-chapter__num {
  position: relative;
  z-index: 0;
  flex: none;
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  font-family: var(--font-mono);
  font-size: var(--fs-14);
  letter-spacing: 0.06em;
  color: #8a6116;
}

.page-about .about-chapter__num::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background: rgba(217, 164, 65, 0.12);
  border: 1px solid rgba(217, 164, 65, 0.55);
  clip-path: polygon(0 0, 100% 0, 100% 70%, 70% 100%, 0 100%);
}

.page-about .about-chapter h2 {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(1.35rem, 3.2vw, 1.95rem);
  font-weight: 700;
  line-height: 1.35;
  letter-spacing: -0.01em;
  color: var(--c-ink);
}

.page-about .about-chapter > p {
  margin: 0 0 1.1em;
  max-width: 68ch;
  font-size: var(--fs-16);
  line-height: 1.85;
  color: var(--c-ink);
}

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

/* ---------- 四个动作 ---------- */
.page-about .about-actions {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line-strong);
  border-top: 1px solid var(--line-strong);
  border-bottom: 1px solid var(--line-strong);
}

.page-about .about-actions li {
  position: relative;
  padding: 22px 20px;
  background: var(--c-paper);
}

.page-about .about-actions li::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 14px;
  height: 14px;
  background: linear-gradient(225deg, rgba(217, 164, 65, 0.55) 0 50%, transparent 50%);
}

.page-about .about-actions__num {
  display: block;
  margin-bottom: 8px;
  font-size: var(--fs-12);
  letter-spacing: 0.12em;
  color: #8a6116;
}

/* ---------- 通用小标题 ---------- */
.page-about .about-actions h3,
.page-about .about-review__steps h3,
.page-about .about-versions__body h3 {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-size: var(--fs-18);
  font-weight: 700;
  line-height: 1.45;
  color: var(--c-ink);
}

.page-about .about-actions p,
.page-about .about-review__steps p,
.page-about .about-versions__body p {
  margin: 0;
  font-size: var(--fs-14);
  line-height: 1.8;
  color: var(--about-muted);
}

/* ---------- 数字带 ---------- */
.page-about .about-stats {
  display: grid;
  gap: 1px;
  margin: 24px 0;
  background: var(--line-strong);
  border: 1px solid var(--line-strong);
}

.page-about .about-stats > div {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 18px;
  background: var(--c-porcelain);
}

.page-about .about-stats b {
  font-family: var(--font-mono);
  font-size: clamp(1.5rem, 4vw, 2rem);
  font-weight: 500;
  line-height: 1;
  color: var(--c-indigo);
}

.page-about .about-stats span {
  font-size: var(--fs-12);
  letter-spacing: 0.04em;
  color: var(--about-muted);
}

/* ---------- 图片块 ---------- */
.page-about .about-chapter__figure {
  margin: 28px 0;
}

.page-about .about-chapter__figure img,
.page-about .about-versions__figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  border: 1px solid var(--line-strong);
}

.page-about .about-chapter__figure .figure__caption,
.page-about .about-versions__figure .figure__caption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.04em;
  color: var(--about-muted);
}

/* ---------- 审核流程 ---------- */
.page-about .about-review {
  margin: 26px 0;
  border-top: 1px solid var(--line-strong);
  border-bottom: 1px solid var(--line-strong);
  padding: 24px 0;
}

.page-about .about-review__svg {
  display: block;
  width: 100%;
  height: auto;
  max-width: 640px;
  margin: 0 auto 20px;
}

.page-about .about-review__steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 18px;
}

.page-about .about-review__steps li {
  padding-left: 16px;
  border-left: 1px solid rgba(217, 164, 65, 0.5);
}

/* ---------- 版本 ---------- */
.page-about .about-versions__wrap {
  margin-top: 26px;
  display: grid;
  gap: 28px;
}

.page-about .about-versions {
  list-style: none;
  margin: 0;
  padding: 0 0 0 22px;
  border-left: 1px solid var(--line-strong);
}

.page-about .about-versions__item {
  position: relative;
  padding-bottom: 24px;
}

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

.page-about .about-versions__item::before {
  content: "";
  position: absolute;
  top: 5px;
  left: -27px;
  width: 9px;
  height: 9px;
  background: var(--c-porcelain);
  border: 1px solid var(--c-amber);
  transform: rotate(45deg);
}

.page-about .about-versions__tag {
  display: block;
  margin-bottom: 6px;
  font-size: var(--fs-12);
  letter-spacing: 0.1em;
  color: #8a6116;
}

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

/* ---------- 联系与合作 ---------- */
.page-about .about-contact {
  margin: 26px 0 18px;
  display: grid;
  gap: 1px;
  background: var(--line-strong);
  border: 1px solid var(--line-strong);
}

.page-about .about-contact__row {
  display: grid;
  gap: 4px;
  padding: 14px 16px;
  background: var(--c-paper);
  font-size: var(--fs-14);
  line-height: 1.7;
  color: var(--c-ink);
  word-break: break-word;
  overflow-wrap: anywhere;
}

.page-about .about-contact__row .mono {
  font-size: var(--fs-12);
  letter-spacing: 0.12em;
  color: var(--about-muted);
}

.page-about .about-contact__note {
  margin: 0 0 24px;
  max-width: 68ch;
  font-size: var(--fs-14);
  line-height: 1.8;
  color: var(--about-muted);
}

.page-about .about-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 22px;
  padding-top: 18px;
  border-top: 1px solid var(--line-strong);
}

.page-about .about-links a {
  position: relative;
  color: var(--c-ink);
  text-decoration: none;
  font-size: var(--fs-14);
  padding-bottom: 3px;
}

.page-about .about-links a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 0;
  height: 1px;
  background: var(--c-amber);
  transition: width 200ms var(--ease);
}

.page-about .about-links a:hover::after,
.page-about .about-links a:focus-visible::after {
  width: 100%;
}

.page-about .about-links a:focus-visible {
  outline: 2px solid var(--c-amber);
  outline-offset: 3px;
}

/* ---------- 中等屏 ---------- */
@media (min-width: 600px) {
  .page-about .about-stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

  .page-about .about-review__steps {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 20px;
  }

  .page-about .about-contact__row {
    grid-template-columns: 72px minmax(0, 1fr);
    align-items: baseline;
  }
}

/* ---------- 大屏 ---------- */
@media (min-width: 900px) {
  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 1.18fr) minmax(0, 0.82fr);
    align-items: end;
  }

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

@media (min-width: 1024px) {
  .page-about .about-body__inner {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-rail {
    display: block;
    position: sticky;
    top: calc(var(--header-h) + 24px);
    padding-left: 20px;
    border-left: 1px solid var(--line-strong);
  }

  .page-about .about-versions__wrap {
    grid-template-columns: minmax(0, 1fr) 240px;
    align-items: start;
    gap: 32px;
  }

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

@media (min-width: 1280px) {
  .page-about .about-rail {
    padding-left: 24px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-rail__link,
  .page-about .about-rail__stamp,
  .page-about .about-links a::after {
    transition: none;
  }
}
<<<END>>>