.page-about {
  --about-rail-w: 218px;
  --about-accent: var(--amber);
  position: relative;
  padding: clamp(18px, 4vw, 36px) var(--gutter) clamp(56px, 8vw, 96px);
  color: var(--ink);
  font-family: var(--font-body);
  background-color: var(--paper);
  background-image:
    linear-gradient(to right, rgba(217, 210, 195, .38) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(217, 210, 195, .38) 1px, transparent 1px);
  background-size: 72px 72px;
  background-position: -1px -1px;
  overflow-x: hidden;
}

.page-about *,
.page-about *::before,
.page-about *::after {
  box-sizing: border-box;
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumb {
  max-width: var(--page-max);
  margin: 0 auto 14px;
}

.page-about .breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 0;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .04em;
}

.page-about .breadcrumb__item + .breadcrumb__item::before {
  content: "/";
  margin-right: 8px;
  color: var(--teal-gray);
}

.page-about .breadcrumb__link {
  color: var(--ink-soft);
  text-decoration: none;
}

.page-about .breadcrumb__link:hover {
  color: var(--deep-teal);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .breadcrumb__link[aria-current="page"] {
  color: var(--lake);
}

/* ---------- 首屏封面 ---------- */
.page-about .about-hero {
  display: grid;
  gap: clamp(22px, 4vw, 40px);
  max-width: var(--page-max);
  margin: 0 auto;
  padding: clamp(22px, 4vw, 44px);
  background: var(--card);
  border: var(--line);
  border-top: 3px solid var(--amber);
}

.page-about .about-hero__meta {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 0 0 16px;
  flex-wrap: wrap;
}

.page-about .about-hero__sep {
  width: 34px;
  height: 1px;
  background: var(--grid);
}

.page-about .about-hero h1 {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: clamp(30px, 7.4vw, 52px);
  line-height: 1.08;
  letter-spacing: -.01em;
  margin: 0 0 18px;
  color: var(--ink);
}

.page-about .about-hero__lead {
  font-size: clamp(16px, 2.2vw, 18px);
  line-height: 1.8;
  color: var(--ink-soft);
  margin: 0 0 24px;
  max-width: 46ch;
}

.page-about .about-hero__facts {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 26px;
  list-style: none;
  margin: 0 0 26px;
  padding: 16px 0 0;
  border-top: 1px dashed var(--grid);
}

.page-about .about-fact {
  display: flex;
  flex-direction: column;
  gap: 3px;
  min-width: 88px;
}

.page-about .about-fact__num {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 22px;
  color: var(--lake);
  line-height: 1.1;
}

.page-about .about-fact__label {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--teal-gray);
  letter-spacing: .03em;
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

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

.page-about .about-hero__figure img,
.page-about .about-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--grid);
  background: var(--paper-deep);
}

.page-about .img-caption {
  margin-top: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--teal-gray);
  line-height: 1.6;
}

/* ---------- 轨道 + 正文 ---------- */
.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 4vw, 40px);
  max-width: var(--page-max);
  margin: clamp(34px, 5vw, 56px) auto 0;
}

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

.page-about .about-rail__label {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .2em;
  color: var(--teal-gray);
}

.page-about .about-rail__list {
  display: flex;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 0 0 6px;
  overflow-x: auto;
}

.page-about .about-rail__item {
  position: relative;
  flex: 0 0 auto;
}

.page-about .about-rail__link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 7px 12px;
  white-space: nowrap;
  font-size: 14px;
  color: var(--ink-soft);
  text-decoration: none;
  background: var(--card);
  border: 1px solid var(--grid);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.page-about .about-rail__link:hover {
  color: var(--deep-teal);
  border-color: var(--orange);
  background: #FFF9F1;
}

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

.page-about .about-rail__num {
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: var(--lake);
  letter-spacing: .06em;
}

/* ---------- 章节 ---------- */
.page-about .about-body {
  min-width: 0;
}

.page-about .about-section {
  padding-top: clamp(22px, 4vw, 34px);
  margin-top: clamp(34px, 5vw, 56px);
  border-top: var(--line);
}

.page-about .about-section:first-child {
  margin-top: 0;
  padding-top: 0;
  border-top: 0;
}

.page-about .chapter {
  display: flex;
  align-items: baseline;
  gap: 14px;
  margin-bottom: 16px;
}

.page-about .chapter__num {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--lake);
  border: 1px solid var(--lake);
  padding: 2px 7px;
  line-height: 1.4;
  flex: 0 0 auto;
}

.page-about .chapter__name {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: clamp(22px, 4vw, 30px);
  line-height: 1.25;
  color: var(--ink);
}

.page-about .about-section p {
  max-width: 66ch;
  margin: 0 0 1em;
  font-size: 16px;
  line-height: 1.85;
  color: var(--ink-soft);
}

.page-about .about-lead {
  font-family: var(--font-head);
  font-weight: 600;
  font-size: clamp(17px, 2.4vw, 20px);
  line-height: 1.65;
  color: var(--ink) !important;
}

.page-about .about-figure {
  margin: 20px 0 24px;
}

/* ---------- 三条做法 ---------- */
.page-about .ways {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .way {
  background: var(--card);
  border: var(--line);
  border-left: 3px solid var(--lake);
  padding: 16px 18px 18px;
}

.page-about .way:nth-child(2) {
  border-left-color: var(--orange);
}

.page-about .way:nth-child(3) {
  border-left-color: var(--teal-gray);
}

.page-about .way__num {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--lake);
}

.page-about .way__title {
  margin: 0 0 8px;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 19px;
  line-height: 1.4;
  color: var(--ink);
}

.page-about .way__text {
  margin: 0 !important;
  font-size: 15.5px !important;
  line-height: 1.8;
}

.page-about .way__gain {
  margin: 12px 0 0 !important;
  padding-top: 10px;
  border-top: 1px dashed var(--grid);
  font-size: 14.5px !important;
  color: var(--deep-teal) !important;
}

.page-about .way__gain-label {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .1em;
  color: var(--amber-ink);
  margin-right: 6px;
}

/* ---------- 场景 ---------- */
.page-about .about-scenes {
  display: grid;
  gap: 12px;
  list-style: none;
  margin: 20px 0 0;
  padding: 0;
}

.page-about .scene {
  background: var(--paper-deep);
  border: 1px solid var(--grid);
  padding: 15px 17px;
}

.page-about .scene__tag {
  margin: 0 0 5px !important;
  font-family: var(--font-mono);
  font-size: 11.5px !important;
  letter-spacing: .1em;
  color: var(--lake) !important;
}

.page-about .scene__title {
  margin: 0 0 6px;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 17px;
  line-height: 1.45;
  color: var(--ink);
}

.page-about .scene__text {
  margin: 0 !important;
  font-size: 14.8px !important;
  line-height: 1.75;
}

/* ---------- 时间线 ---------- */
.page-about .timeline {
  list-style: none;
  margin: 24px 0 0;
  padding: 0 0 0 22px;
  position: relative;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: linear-gradient(to bottom, var(--amber), var(--orange), var(--mist));
}

.page-about .timeline > li {
  position: relative;
  margin-bottom: 10px;
}

.page-about .timeline > li::before {
  content: "";
  position: absolute;
  left: -22px;
  top: 17px;
  width: 9px;
  height: 9px;
  background: var(--card);
  border: 2px solid var(--orange);
  border-radius: 1px;
}

.page-about .timeline > li:last-child::before {
  background: var(--amber);
  border-color: var(--amber);
}

.page-about .tl {
  background: var(--card);
  border: var(--line);
  transition: border-color var(--dur) var(--ease);
}

.page-about .tl[open] {
  border-color: var(--orange);
}

.page-about .tl summary {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 10px;
  padding: 12px 15px;
  cursor: pointer;
  list-style: none;
}

.page-about .tl summary::-webkit-details-marker {
  display: none;
}

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

.page-about .tl__ver {
  font-family: var(--font-mono);
  font-size: 12px;
  padding: 2px 7px;
  border: 1px solid var(--mist);
  background: #F2F7F8;
  color: var(--deep-teal);
  border-radius: 2px;
  flex: 0 0 auto;
}

.page-about .tl--current .tl__ver {
  background: var(--amber);
  border-color: var(--amber);
  color: var(--ink);
}

.page-about .tl__name {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 16.5px;
  color: var(--ink);
}

.page-about .tl__hint {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: var(--teal-gray);
  letter-spacing: .06em;
}

.page-about .tl[open] .tl__hint {
  color: var(--amber-ink);
}

.page-about .tl__body {
  padding: 12px 15px 15px;
  margin: 0 15px;
  padding-left: 0;
  padding-right: 0;
  border-top: 1px dashed var(--grid);
  font-size: 14.8px;
  line-height: 1.8;
  color: var(--ink-soft);
}

/* ---------- 服务承诺 ---------- */
.page-about .promises {
  list-style: none;
  margin: 20px 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .promise {
  border-left: 2px solid var(--mist);
  padding: 2px 0 2px 14px;
}

.page-about .promise__title {
  margin: 0 0 4px;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 16.5px;
  line-height: 1.5;
  color: var(--deep-teal);
}

.page-about .promise__text {
  margin: 0 !important;
  font-size: 14.8px !important;
  line-height: 1.78;
}

.page-about .about-contact {
  margin-top: 22px;
  padding: 16px 18px;
  background: var(--card);
  border: 1px solid var(--grid);
  border-left: 3px solid var(--amber);
}

.page-about .about-contact p {
  margin: 0 0 6px;
  max-width: none;
  font-size: 14.8px;
  line-height: 1.8;
}

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

.page-about .about-contact a {
  color: var(--deep-teal);
  text-decoration: underline;
  text-underline-offset: 3px;
  font-family: var(--font-mono);
  font-size: 14px;
}

.page-about .about-contact a:hover {
  color: var(--amber-ink);
}

.page-about .about-contact__mono {
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--ink);
}

.page-about .about-contact__note {
  color: var(--teal-gray) !important;
  font-size: 13.5px !important;
}

/* ---------- 结尾路径 ---------- */
.page-about .about-cta {
  display: grid;
  gap: 20px;
  max-width: var(--page-max);
  margin: clamp(40px, 6vw, 68px) auto 0;
  padding: clamp(24px, 4vw, 42px);
  background: var(--deep-teal);
  color: var(--paper);
}

.page-about .about-cta h2 {
  margin: 0 0 10px;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: clamp(21px, 3.4vw, 29px);
  line-height: 1.3;
  color: #FFFFFF;
}

.page-about .about-cta p {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: #CFE0E2;
  max-width: 46ch;
}

.page-about .about-cta__links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-cta__link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 14px;
  font-size: 14.5px;
  color: var(--paper);
  text-decoration: none;
  border: 1px solid rgba(247, 243, 234, .38);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.page-about .about-cta__link::after {
  content: "→";
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--orange);
}

.page-about .about-cta__link:hover {
  color: var(--orange);
  border-color: var(--orange);
  transform: translateX(2px);
}

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

/* ---------- 中等屏 ---------- */
@media (min-width: 700px) {
  .page-about .about-hero__facts {
    gap: 10px 40px;
  }

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

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

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

/* ---------- 桌面：左轨道 + 右正文 ---------- */
@media (min-width: 900px) {
  .page-about .about-hero {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
    align-items: center;
    padding: clamp(30px, 3.4vw, 52px);
  }

  .page-about .about-hero__figure {
    align-self: stretch;
  }

  .page-about .about-hero__figure img {
    height: 100%;
    min-height: 300px;
  }

  .page-about .about-layout {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: clamp(30px, 4vw, 56px);
    align-items: start;
  }

  .page-about .about-rail {
    position: sticky;
    top: 96px;
    border-left: 2px solid var(--grid);
    padding-left: 18px;
  }

  .page-about .about-rail__list {
    flex-direction: column;
    gap: 2px;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .about-rail__item {
    flex: 0 0 auto;
  }

  .page-about .about-rail__item::before {
    content: "";
    position: absolute;
    left: -23px;
    top: 15px;
    width: 7px;
    height: 7px;
    background: var(--card);
    border: 1px solid var(--teal-gray);
    border-radius: 50%;
  }

  .page-about .about-rail__link {
    display: flex;
    width: 100%;
    padding: 8px 8px 8px 0;
    background: transparent;
    border: 0;
    border-bottom: 1px dashed transparent;
    font-size: 14.5px;
    white-space: normal;
  }

  .page-about .about-rail__link:hover {
    background: transparent;
    border-bottom-color: var(--orange);
    color: var(--deep-teal);
  }

  .page-about .way {
    padding: 18px 22px 20px;
  }

  .page-about .about-cta {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
    align-items: center;
    gap: 32px;
  }
}

@media (min-width: 1120px) {
  .page-about .about-hero h1 {
    max-width: 15ch;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-rail__link,
  .page-about .about-cta__link,
  .page-about .tl {
    transition: none;
  }

  .page-about .about-cta__link:hover {
    transform: none;
  }
}
<<<END>>>