.page-about {
  --about-rail: 22px;
  --about-dot: 7px;
}

.page-about .about-shell {
  padding-bottom: 48px;
}

/* 面包屑 */
.page-about .crumbs {
  margin: 6px 0 18px;
  font-size: 13px;
}

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

.page-about .crumbs a {
  color: var(--stone);
  text-decoration: none;
}

.page-about .crumbs a:hover,
.page-about .crumbs a:focus-visible {
  color: var(--butter);
}

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

/* 首屏 */
.page-about .about-hero {
  display: grid;
  gap: 26px;
  margin-bottom: 40px;
}

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

.page-about .about-hero h1 {
  margin: 0 0 18px;
  font-family: var(--font-serif);
  font-size: clamp(29px, 6.6vw, 58px);
  font-weight: 700;
  line-height: 1.16;
  letter-spacing: .01em;
  color: var(--text);
}

.page-about .about-hero__lead {
  margin: 0 0 14px;
  max-width: 42em;
  font-size: 16px;
  line-height: 1.85;
  color: var(--text);
}

.page-about .about-hero__lead strong {
  color: var(--butter);
  font-weight: 700;
}

.page-about .about-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px 18px;
  margin-top: 24px;
  padding-top: 18px;
  border-top: 1px solid var(--line-soft);
}

.page-about .about-fact {
  display: flex;
  flex-direction: column;
  gap: 2px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--stone);
}

.page-about .about-fact .ledger {
  font-size: 23px;
  letter-spacing: .02em;
  color: var(--butter);
}

.page-about .about-hero__figure {
  border: 1px solid var(--line);
  background: var(--panel);
  padding: 10px;
}

.page-about .figure__media {
  display: block;
  overflow: hidden;
}

.page-about .figure__media img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .figure__cap {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--stone);
}

/* 贯穿全页的金线刻度 */
.page-about .about-flow {
  position: relative;
  padding-left: var(--about-rail);
}

.page-about .about-flow::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 1px;
  background: linear-gradient(180deg, var(--gold) 0%, rgba(192, 138, 46, .38) 55%, rgba(192, 138, 46, .1) 100%);
}

.page-about .about-sec {
  position: relative;
  padding: 8px 0 4px;
}

.page-about .about-sec + .about-sec {
  margin-top: 46px;
}

.page-about .about-sec::before {
  content: "";
  position: absolute;
  left: -25.5px;
  top: 20px;
  width: var(--about-dot);
  height: var(--about-dot);
  border-radius: 50%;
  background: var(--cinnabar);
  box-shadow: 0 0 0 3px rgba(169, 58, 43, .16);
}

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

.page-about .about-intro {
  margin: 16px 0 0;
  max-width: 44em;
  font-size: 16px;
  line-height: 1.85;
  color: var(--text);
}

.page-about .about-note {
  margin: 8px 0 0;
  font-size: 14px;
  line-height: 1.9;
  color: var(--stone);
  word-break: break-word;
}

.page-about .about-links {
  margin: 22px 0 0;
  font-size: 14px;
  line-height: 1.9;
  color: var(--stone);
}

.page-about .about-links a {
  color: var(--butter);
  text-decoration: none;
  border-bottom: 1px solid var(--line);
}

.page-about .about-links a:hover {
  border-bottom-color: var(--butter);
}

/* 侧边资料卡 */
.page-about .about-aside {
  margin-top: 22px;
  border: 1px solid var(--line);
  border-left: 2px solid var(--mineral);
  background: var(--panel);
  padding: 16px 18px;
}

.page-about .about-aside--quiet {
  border-left-color: var(--gold);
}

.page-about .about-aside__title {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--gold);
}

.page-about .about-aside__list,
.page-about .about-aside__links {
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 14px;
  line-height: 1.95;
  color: var(--text);
}

.page-about .about-aside__list .ledger {
  font-size: 15px;
  color: var(--butter);
}

.page-about .about-aside__links a {
  color: var(--text);
  text-decoration: none;
  border-bottom: 1px solid transparent;
}

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

/* 三条准则 */
.page-about .tenets {
  margin: 22px 0 0;
}

.page-about .tenet {
  padding: 24px 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .tenet:last-child {
  border-bottom: 1px solid var(--line-soft);
}

.page-about .tenet__head {
  display: grid;
  grid-template-columns: 1.45em minmax(0, 1fr);
  gap: 8px 14px;
  align-items: start;
}

.page-about .tenet__num {
  font-family: var(--font-serif);
  font-size: 34px;
  line-height: 1;
  color: var(--gold);
}

.page-about .tenet__claim {
  margin: 0;
  font-family: var(--font-serif);
  font-size: clamp(18px, 4.2vw, 25px);
  font-weight: 400;
  line-height: 1.5;
  color: var(--text);
}

.page-about .tenet__claim b {
  color: var(--butter);
  font-weight: 700;
}

.page-about .tenet__fold {
  margin-top: 24px;
  margin-left: 0;
}

.page-about .fold__body p {
  margin: 0 0 10px;
  font-size: 15px;
  line-height: 1.9;
  color: var(--text);
}

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

/* 留白与小幅配图 */
.page-about .about-pause {
  display: flex;
  justify-content: flex-end;
  margin: 54px 0;
}

.page-about .about-pause__fig {
  width: min(290px, 100%);
  margin: 0;
  border: 1px solid var(--line);
  background: var(--panel);
  padding: 8px;
}

/* 历程 */
.page-about .timeline-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 18px 0 22px;
  padding: 0;
  list-style: none;
}

.page-about .timeline-nav a {
  display: inline-block;
  padding: 6px 12px;
  border: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .04em;
  color: var(--butter);
  text-decoration: none;
}

.page-about .timeline-nav a:hover,
.page-about .timeline-nav a:focus-visible {
  border-color: var(--butter);
  background: rgba(242, 190, 85, .08);
}

.page-about .timeline {
  display: grid;
  gap: 18px;
}

.page-about .milestone {
  border: 1px solid var(--line);
  background: var(--panel);
  padding: 16px 18px;
  box-shadow: var(--shadow-card);
  scroll-margin-top: 80px;
}

.page-about .milestone__year {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 20px;
  font-weight: 700;
  letter-spacing: .05em;
  color: var(--butter);
}

.page-about .milestone p {
  margin: 8px 0 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--text);
}

.page-about .milestone__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

/* 团队 */
.page-about .team {
  display: grid;
  gap: 24px;
  margin-top: 18px;
}

.page-about .team__groups {
  display: grid;
  gap: 16px;
  margin-top: 18px;
}

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

.page-about .team__group h3 {
  margin: 0 0 6px;
  font-family: var(--font-serif);
  font-size: 18px;
  font-weight: 700;
  color: var(--butter);
}

.page-about .team__group p {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--text);
}

.page-about .about-team__fig {
  margin: 0;
  border: 1px solid var(--line);
  background: var(--panel);
  padding: 8px;
}

/* 两步法 */
.page-about .flow {
  display: grid;
  gap: 10px;
  margin-top: 24px;
}

.page-about .flow__step {
  border: 1px solid var(--line);
  background: var(--panel);
  padding: 16px;
  transition: border-color .3s var(--ease);
}

.page-about .flow__step:hover {
  border-color: var(--butter);
}

.page-about .flow__step--done {
  border-left: 2px solid var(--cinnabar);
}

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

.page-about .flow__step h3 {
  margin: 6px 0 8px;
  font-family: var(--font-serif);
  font-size: 19px;
  font-weight: 700;
  color: var(--text);
}

.page-about .flow__step p {
  margin: 0 0 12px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--text);
}

.page-about .flow__file {
  display: inline-block;
  padding: 3px 9px;
  border: 1px solid var(--mineral);
  font-size: 13px;
  line-height: 1.5;
  color: var(--mineral-light);
  transition: color .25s var(--ease), border-color .25s var(--ease);
}

.page-about .flow__step:hover .flow__file {
  color: var(--butter);
  border-color: var(--butter);
}

.page-about .flow__arrow {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  color: var(--gold);
}

.page-about .flow__arrow svg {
  display: block;
  transform: rotate(90deg);
}

.page-about .flow__arrow span {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--stone);
}

/* 返回顶部 */
.page-about .backtop {
  position: fixed;
  right: 14px;
  bottom: 18px;
  z-index: 20;
}

.page-about .backtop a {
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border: 1px solid var(--line);
  background: rgba(13, 10, 7, .88);
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.2;
  color: var(--butter);
  text-decoration: none;
}

.page-about .backtop a:hover,
.page-about .backtop a:focus-visible {
  border-color: var(--butter);
}

/* 中等屏 */
@media (min-width: 720px) {
  .page-about .about-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-cols {
    margin-top: 22px;
  }

  .page-about .about-aside {
    margin-top: 0;
  }

  .page-about .tenet__head {
    grid-template-columns: 1.6em minmax(0, 1fr);
    gap: 10px 22px;
  }

  .page-about .tenet__num {
    font-size: 44px;
  }

  .page-about .tenet__fold {
    margin-left: calc(1.6em + 22px);
  }

  .page-about .about-pause {
    margin: 64px 0;
  }

  .page-about .about-pause__fig {
    width: min(320px, 100%);
  }
}

/* 桌面：错层齿状历程与双栏内容 */
@media (min-width: 880px) {
  .page-about .about-hero {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: 56px;
    align-items: end;
  }

  .page-about .milestone:nth-child(odd) {
    margin-right: 18%;
  }

  .page-about .milestone:nth-child(even) {
    margin-left: 18%;
  }

  .page-about .team {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: 48px;
    align-items: start;
  }

  .page-about .flow {
    grid-template-columns: minmax(0, 1fr) 72px minmax(0, 1fr) 72px minmax(0, 1fr);
    align-items: stretch;
    gap: 14px;
  }

  .page-about .flow__arrow {
    flex-direction: column;
  }

  .page-about .flow__arrow svg {
    transform: none;
  }

  .page-about .backtop {
    right: 24px;
    bottom: 26px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .flow__step,
  .page-about .flow__file {
    transition: none;
  }
}
<<<END>>>