.page-about {
  position: relative;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.65;
  color: var(--paper);
  background:
    radial-gradient(120% 55% at 78% 0%, rgba(15, 42, 40, .9) 0%, rgba(10, 20, 17, 0) 62%),
    linear-gradient(180deg, var(--ink) 0%, var(--ink-2) 48%, var(--ink) 100%);
}

.page-about h1,
.page-about h2,
.page-about h3 {
  margin: 0;
  font-family: var(--font-sans);
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1.2;
  color: var(--paper);
}

.page-about p {
  margin: 0 0 14px;
}

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

.page-about .mono {
  font-family: var(--font-mono);
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  border-bottom: 1px solid var(--line);
  background: linear-gradient(158deg, var(--night) 0%, rgba(10, 20, 17, .25) 58%, rgba(20, 24, 26, .92) 100%);
}

.page-about .about-hero__inner {
  position: relative;
  z-index: 2;
  padding-top: clamp(24px, 4vw, 52px);
  padding-bottom: clamp(22px, 3.5vw, 36px);
}

.page-about .about-hero .breadcrumb {
  margin-bottom: 22px;
  font-size: 13px;
  color: var(--mute);
}

.page-about .about-hero .breadcrumb a {
  color: var(--mute);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 180ms var(--ease), border-color 180ms var(--ease);
}

.page-about .about-hero .breadcrumb a:hover,
.page-about .about-hero .breadcrumb a:focus-visible {
  color: var(--lime);
  border-bottom-color: var(--lime);
}

.page-about .about-hero .eyebrow {
  margin-bottom: 14px;
}

.page-about .about-hero__title {
  font-size: clamp(36px, 8.6vw, 72px);
  max-width: 20ch;
}

.page-about .about-hero__lead {
  margin-top: 20px;
  max-width: 60ch;
  font-size: clamp(16px, 1.6vw, 18px);
  color: rgba(243, 245, 239, .82);
}

.page-about .about-hero__meta {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px 20px;
  margin: 30px 0 0;
  padding: 20px 0 0;
  border-top: 1px solid var(--line);
}

.page-about .about-hero__meta li {
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-width: 0;
}

.page-about .about-hero__meta .k {
  font-size: clamp(18px, 2.4vw, 24px);
  line-height: 1.15;
  color: var(--lime);
  font-weight: 700;
}

.page-about .about-hero__meta .v {
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--mute);
}

.page-about .about-hero__media {
  padding-bottom: clamp(28px, 4.5vw, 52px);
}

.page-about .media-frame {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: var(--ink-2);
}

.page-about .media-frame img {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .about-hero__frame {
  aspect-ratio: 16 / 7;
}

.page-about .about-hero__frame img {
  height: 100%;
  object-fit: cover;
}

.page-about .media-cap {
  margin: 10px 0 0;
  font-size: 11px;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--mute);
}

/* ---------- 主体骨架 ---------- */

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

.page-about .about-flow {
  min-width: 0;
  padding-top: 4px;
}

/* ---------- 左缘年份刻度 ---------- */

.page-about .about-rail {
  padding: 26px 0 8px;
}

.page-about .about-rail__title {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--mute);
}

.page-about .about-rail__list {
  display: flex;
  gap: 4px;
  margin: 0;
  padding: 0;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
}

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

.page-about .about-rail__list a {
  position: relative;
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding-left: 17px;
  padding-right: 6px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .08em;
  color: var(--mute);
  text-decoration: none;
  white-space: nowrap;
  transition: color 180ms var(--ease);
}

.page-about .about-rail__list a::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: 7px;
  height: 7px;
  margin-top: -3.5px;
  border-radius: 50%;
  border: 1px solid var(--line);
  background: var(--ink);
  transition: background 180ms var(--ease), border-color 180ms var(--ease);
}

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

.page-about .about-rail__list a:hover::before,
.page-about .about-rail__list a:focus-visible::before {
  border-color: var(--lime);
  background: var(--lime);
}

.page-about .about-rail__list a:focus-visible {
  outline: 2px solid var(--lime);
  outline-offset: 2px;
  border-radius: var(--r-xs);
}

/* ---------- 章节 ---------- */

.page-about .about-chapter {
  padding: clamp(40px, 6vw, 84px) 0;
  border-top: 1px solid var(--line);
  scroll-margin-top: 112px;
}

.page-about .about-chapter:first-child {
  border-top: 0;
  padding-top: clamp(28px, 4vw, 48px);
}

.page-about .about-chapter__head {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  margin-bottom: clamp(18px, 2.6vw, 30px);
}

.page-about .about-chapter__no {
  flex: 0 0 auto;
  padding-top: 10px;
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--lime);
}

.page-about .about-chapter__title {
  flex: 1 1 auto;
  min-width: 0;
  font-size: clamp(25px, 3.6vw, 44px);
}

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

.page-about .about-prose {
  max-width: 68ch;
}

.page-about .about-prose p {
  max-width: 62ch;
  color: rgba(243, 245, 239, .84);
}

/* ---------- 时间线 ---------- */

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

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 8px;
  top: 12px;
  bottom: 24px;
  width: 1px;
  background: linear-gradient(180deg, var(--lime) 0%, var(--line) 18%, var(--line) 84%, rgba(44, 63, 56, 0) 100%);
}

.page-about .about-timeline__item {
  position: relative;
  padding: 0 0 clamp(28px, 3.6vw, 42px) 34px;
  scroll-margin-top: 112px;
}

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: 1px;
  top: 6px;
  width: 15px;
  height: 15px;
  border-radius: 50%;
  border: 1px solid var(--line);
  background: var(--ink);
}

.page-about .about-timeline__item:first-child::before {
  border-color: var(--lime);
  box-shadow: 0 0 0 4px rgba(184, 255, 61, .12);
}

.page-about .about-timeline__year {
  display: block;
  margin-bottom: 6px;
  font-size: 22px;
  line-height: 1;
  letter-spacing: .04em;
  color: var(--lime);
}

.page-about .about-timeline__title {
  margin-bottom: 8px;
  font-size: 19px;
}

.page-about .about-timeline__item p {
  max-width: 58ch;
  font-size: 15px;
  color: rgba(243, 245, 239, .78);
}

.page-about .about-timeline__figure {
  position: relative;
  list-style: none;
  padding: 0 0 clamp(28px, 3.6vw, 42px) 34px;
}

.page-about .about-figure {
  margin: 0;
  max-width: 300px;
}

.page-about .about-figure .media-frame {
  aspect-ratio: 4 / 5;
}

.page-about .about-figure img {
  height: 100%;
  object-fit: cover;
}

/* ---------- 数据来源步骤 ---------- */

.page-about .about-steps {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .about-steps > li {
  display: grid;
  grid-template-columns: 42px minmax(0, 1fr);
  gap: 6px 16px;
  padding: 20px 0;
  border-bottom: 1px solid var(--line);
  transition: background 180ms var(--ease);
}

.page-about .about-steps > li:hover {
  background: rgba(28, 58, 49, .4);
}

.page-about .about-steps__no {
  padding-top: 3px;
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--lime);
}

.page-about .about-steps h3 {
  margin-bottom: 6px;
  font-size: 18px;
}

.page-about .about-steps p {
  max-width: 60ch;
  font-size: 15px;
  color: rgba(243, 245, 239, .78);
}

/* ---------- 团队 ---------- */

.page-about .about-team {
  display: grid;
  gap: 26px;
}

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

.page-about .about-team__frame {
  aspect-ratio: 3 / 2;
}

.page-about .about-team__frame img {
  height: 100%;
  object-fit: cover;
}

.page-about .about-team__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  overflow: hidden;
}

.page-about .about-team__item {
  display: grid;
  grid-template-columns: 52px minmax(0, 1fr);
  gap: 14px;
  align-items: start;
  padding: 18px 20px;
  background: var(--ink-2);
  transition: background 180ms var(--ease), box-shadow 180ms var(--ease);
}

.page-about .about-team__item:hover {
  background: var(--field);
  box-shadow: inset 0 0 0 1px var(--lime);
}

.page-about .about-team__num {
  font-size: 26px;
  line-height: 1.1;
  font-weight: 700;
  color: var(--lime);
}

.page-about .about-team__item h3 {
  margin-bottom: 6px;
  font-size: 17px;
}

.page-about .about-team__item p {
  font-size: 14px;
  color: rgba(243, 245, 239, .76);
}

/* ---------- 覆盖范围 ---------- */

.page-about .about-scope {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  overflow: hidden;
}

.page-about .about-scope > li {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  grid-template-areas:
    "k t"
    "p p";
  gap: 4px 14px;
  align-items: baseline;
  padding: 22px;
  background: var(--ink-2);
  transition: background 180ms var(--ease), box-shadow 180ms var(--ease);
}

.page-about .about-scope > li:hover {
  background: var(--field);
  box-shadow: inset 0 0 0 1px var(--lime);
}

.page-about .about-scope__k {
  grid-area: k;
  font-size: clamp(30px, 4.4vw, 42px);
  line-height: 1;
  font-weight: 700;
  color: var(--lime);
}

.page-about .about-scope__t {
  grid-area: t;
  font-size: 14px;
  letter-spacing: .04em;
  color: var(--mute);
}

.page-about .about-scope > li p {
  grid-area: p;
  margin: 8px 0 0;
  font-size: 15px;
  color: rgba(243, 245, 239, .78);
}

/* ---------- 三条原则 ---------- */

.page-about .about-principles {
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  overflow: hidden;
}

.page-about .about-principle {
  padding: 24px 22px 26px;
  background: var(--ink-2);
  transition: background 180ms var(--ease), box-shadow 180ms var(--ease);
}

.page-about .about-principle:hover {
  background: var(--field);
  box-shadow: inset 0 0 0 1px var(--lime);
}

.page-about .about-principle__no {
  display: inline-block;
  margin-bottom: 12px;
  font-size: 12px;
  letter-spacing: .2em;
  color: var(--lime);
}

.page-about .about-principle h3 {
  margin-bottom: 10px;
  font-size: 19px;
}

.page-about .about-principle p {
  font-size: 15px;
  color: rgba(243, 245, 239, .78);
}

/* ---------- 收束路径 ---------- */

.page-about .about-closing {
  padding: clamp(28px, 4vw, 52px) 0 clamp(44px, 6vw, 88px);
}

.page-about .path-bar {
  display: grid;
  gap: 20px;
  padding: clamp(22px, 3vw, 32px);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: linear-gradient(135deg, var(--field) 0%, var(--ink-2) 72%);
}

.page-about .path-bar__text {
  margin: 0;
  max-width: 72ch;
  font-size: 15px;
  color: rgba(243, 245, 239, .84);
}

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

/* ---------- 平板 ---------- */

@media (min-width: 700px) {
  .page-about .about-hero__meta {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

/* ---------- 桌面 ---------- */

@media (min-width: 960px) {
  .page-about .about-shell {
    grid-template-columns: 120px minmax(0, 1fr);
    column-gap: clamp(28px, 4vw, 64px);
  }

  .page-about .about-rail {
    position: sticky;
    top: 108px;
    align-self: start;
    padding: 0;
  }

  .page-about .about-rail__title {
    writing-mode: vertical-rl;
    margin: 0 0 14px 4px;
    max-height: 96px;
    overflow: hidden;
    white-space: nowrap;
  }

  .page-about .about-rail__list {
    flex-direction: column;
    gap: 0;
    overflow: visible;
    padding-left: 1px;
    border-left: 1px solid var(--line);
  }

  .page-about .about-rail__list a {
    padding-left: 16px;
    padding-right: 0;
  }

  .page-about .about-rail__list a::before {
    left: -5px;
  }

  .page-about .about-chapter__note {
    display: block;
    flex: 0 0 auto;
    margin-top: 8px;
    max-height: 140px;
    overflow: hidden;
    writing-mode: vertical-rl;
    white-space: nowrap;
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: .18em;
    text-transform: uppercase;
    color: var(--mute);
  }

  .page-about .about-team {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.15fr);
    gap: clamp(28px, 4vw, 56px);
    align-items: start;
  }

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

  .page-about .path-bar {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: 28px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about * {
    transition-duration: 1ms !important;
  }
}