.page-about {
  --about-rail: 176px;
  display: block;
  background: var(--ink);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  padding: clamp(52px, 8vw, 112px) 0 clamp(46px, 7vw, 88px);
  background:
    radial-gradient(115% 95% at 90% 4%, rgba(240, 78, 35, .22), transparent 60%),
    radial-gradient(90% 80% at 4% 108%, rgba(27, 39, 64, .95), transparent 66%),
    var(--ink);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  z-index: -1;
  top: -18%;
  right: -14%;
  width: min(880px, 82%);
  height: 142%;
  background: linear-gradient(158deg, rgba(240, 78, 35, .20) 0%, rgba(232, 176, 75, .07) 46%, rgba(11, 14, 20, 0) 76%);
  clip-path: polygon(30% 0, 100% 0, 100% 100%, 0 88%);
  pointer-events: none;
}

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

.page-about .breadcrumb {
  margin-bottom: clamp(20px, 3vw, 32px);
}

.page-about .breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 13px;
  letter-spacing: .04em;
  color: var(--steel);
}

.page-about .breadcrumb-list li + li::before {
  content: "/";
  margin-right: 8px;
  color: var(--line-strong);
}

.page-about .breadcrumb-list a {
  color: var(--steel);
  text-decoration: none;
}

.page-about .breadcrumb-list a:hover {
  color: var(--flame-hi);
}

.page-about .breadcrumb-current {
  color: var(--cream);
}

.page-about .about-hero .eyebrow {
  margin: 0 0 16px;
  color: var(--gold);
  letter-spacing: .2em;
}

.page-about .about-hero h1 {
  margin: 0 0 clamp(18px, 2.6vw, 28px);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(29px, 4.6vw, 52px);
  line-height: 1.26;
  letter-spacing: .02em;
  color: var(--cream);
  max-width: 17em;
}

.page-about .about-hero-lead {
  margin: 0;
  max-width: 640px;
  font-size: 16px;
  line-height: 1.85;
  color: rgba(243, 237, 228, .78);
}

.page-about .about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(24px, 3.4vw, 34px);
}

.page-about .about-hero-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(32px, 5vw, 52px) 0 0;
  padding: 1px;
  list-style: none;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .about-stat {
  padding: 20px 22px;
  background: linear-gradient(180deg, rgba(27, 39, 64, .74), rgba(16, 24, 43, .74));
}

.page-about .about-stat-num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(22px, 2.4vw, 30px);
  line-height: 1.2;
  letter-spacing: .02em;
  color: var(--cream);
}

.page-about .about-stat-label {
  display: block;
  margin-top: 6px;
  font-size: 13px;
  letter-spacing: .06em;
  color: var(--steel);
}

/* ---------- 长卷主体 ---------- */
.page-about .about-body {
  padding: clamp(8px, 2vw, 20px) 0 clamp(48px, 8vw, 96px);
  background:
    linear-gradient(180deg, rgba(16, 24, 43, .55) 0px, rgba(11, 14, 20, 0) 340px),
    var(--ink);
}

.page-about .about-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 3.4vw, 48px);
}

/* 章节竖轴 */
.page-about .about-rail {
  position: relative;
}

.page-about .about-rail-title {
  margin: 0 0 12px;
  font-size: 12px;
  letter-spacing: .2em;
  color: var(--steel);
}

.page-about .rail-list {
  display: flex;
  gap: 10px;
  margin: 0;
  padding: 0 0 12px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
}

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

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

.page-about .rail-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  background: rgba(16, 24, 43, .66);
  color: var(--steel);
  font-size: 13px;
  line-height: 1;
  text-decoration: none;
  white-space: nowrap;
  transition: color .22s var(--ease), border-color .22s var(--ease), background-color .22s var(--ease);
}

.page-about .rail-link:hover,
.page-about .rail-link:focus-visible {
  color: var(--cream);
  border-color: var(--line-strong);
}

.page-about .rail-num {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--flame);
}

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

.page-about .about-chapter {
  position: relative;
  padding: clamp(38px, 6vw, 72px) 0;
  border-top: 1px solid var(--line);
  scroll-margin-top: 110px;
}

.page-about .about-flow > .about-chapter:first-child {
  border-top: 0;
  padding-top: clamp(14px, 2.6vw, 28px);
}

.page-about .chapter-num {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .2em;
  color: var(--flame);
}

.page-about .chapter-title {
  margin: 0 0 clamp(16px, 2.4vw, 24px);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(23px, 3vw, 33px);
  line-height: 1.34;
  letter-spacing: .02em;
  color: var(--cream);
}

.page-about .chapter-copy {
  max-width: 680px;
}

.page-about .chapter-copy p {
  margin: 0 0 1.1em;
  font-size: 16px;
  line-height: 1.85;
  color: rgba(243, 237, 228, .78);
}

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

.page-about .chapter-copy a {
  color: var(--flame-hi);
  text-decoration: none;
  border-bottom: 1px solid rgba(255, 122, 69, .4);
}

.page-about .chapter-copy a:hover {
  color: var(--gold);
  border-bottom-color: var(--line-gold);
}

/* 图片容器 */
.page-about .about-figure {
  margin: clamp(22px, 3.4vw, 34px) 0;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--navy);
  box-shadow: var(--shadow-soft);
}

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

.page-about .about-figure--team img {
  aspect-ratio: 3 / 2;
}

.page-about .about-figure--version img {
  aspect-ratio: 5 / 3;
}

.page-about .about-figure--map img {
  aspect-ratio: 10 / 7;
}

.page-about .about-figure-cap {
  display: block;
  padding: 12px 16px;
  border-top: 1px solid var(--line);
  background: rgba(11, 14, 20, .62);
  font-size: 13px;
  line-height: 1.7;
  color: var(--steel);
}

/* 岗位构成 */
.page-about .about-roles {
  display: grid;
  gap: 16px;
  margin: clamp(20px, 3vw, 32px) 0 clamp(24px, 3.4vw, 34px);
  max-width: 680px;
}

.page-about .about-role {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  grid-template-areas:
    "name num"
    "bar bar";
  align-items: center;
  gap: 8px 14px;
}

.page-about .about-role-name {
  grid-area: name;
  font-size: 14px;
  letter-spacing: .05em;
  color: var(--cream);
}

.page-about .about-role-bar {
  grid-area: bar;
  display: block;
  height: 8px;
  border-radius: var(--radius-pill);
  background: rgba(154, 166, 188, .14);
  overflow: hidden;
}

.page-about .about-role-bar > span {
  display: block;
  height: 100%;
  border-radius: var(--radius-pill);
  background: linear-gradient(90deg, var(--flame), var(--flame-hi));
}

.page-about .about-role-bar--edit > span {
  width: 42.3%;
}

.page-about .about-role-bar--check > span {
  width: 26.9%;
}

.page-about .about-role-bar--column > span {
  width: 30.8%;
}

.page-about .about-role-num {
  grid-area: num;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--gold);
}

/* 更新节奏 */
.page-about .about-cadence {
  display: grid;
  gap: 1px;
  margin: clamp(20px, 3vw, 32px) 0 0;
  padding: 1px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--line);
  overflow: hidden;
  max-width: 680px;
}

.page-about .about-cadence-item {
  padding: 20px 22px;
  background: rgba(16, 24, 43, .7);
}

.page-about .about-cadence-item dt {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-size: 16px;
  letter-spacing: .02em;
  color: var(--cream);
}

.page-about .about-cadence-item dd {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--steel);
}

/* 版本时间线 */
.page-about .about-timeline {
  display: flex;
  gap: 18px;
  margin: 0 -4px;
  padding: 4px 4px 20px;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
}

.page-about .about-timeline:focus-visible {
  outline: 1px solid var(--line-gold);
  outline-offset: 4px;
  border-radius: var(--radius);
}

.page-about .about-timeline::-webkit-scrollbar {
  height: 6px;
}

.page-about .about-timeline::-webkit-scrollbar-track {
  background: rgba(154, 166, 188, .08);
  border-radius: var(--radius-pill);
}

.page-about .about-timeline::-webkit-scrollbar-thumb {
  background: rgba(240, 78, 35, .45);
  border-radius: var(--radius-pill);
}

.page-about .about-version {
  flex: 0 0 min(340px, 82vw);
  scroll-snap-align: start;
  padding: 26px 24px 28px;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: linear-gradient(180deg, rgba(27, 39, 64, .84), rgba(11, 14, 20, .92));
  box-shadow: var(--shadow-soft);
  transition: border-color .24s var(--ease), transform .24s var(--ease);
}

.page-about .about-version:hover {
  border-color: var(--line-strong);
  transform: translateY(-2px);
}

.page-about .about-version::before {
  content: "";
  display: block;
  width: 46px;
  height: 3px;
  margin-bottom: 18px;
  border-radius: var(--radius-pill);
  background: linear-gradient(90deg, var(--flame), var(--gold));
}

.page-about .version-tag {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .2em;
  color: var(--flame);
}

.page-about .version-title {
  margin: 12px 0 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 20px;
  line-height: 1.4;
  letter-spacing: .02em;
  color: var(--cream);
}

.page-about .version-text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--steel);
}

.page-about .about-timeline-hint {
  margin: 0 0 clamp(18px, 2.6vw, 26px);
  font-size: 13px;
  letter-spacing: .08em;
  color: var(--steel);
}

/* 服务覆盖 */
.page-about .about-coverage {
  display: grid;
  gap: clamp(22px, 3.4vw, 40px);
}

.page-about .about-coverage-copy p {
  margin: 0 0 1.1em;
  max-width: 560px;
  font-size: 16px;
  line-height: 1.85;
  color: rgba(243, 237, 228, .78);
}

.page-about .about-coverage-list {
  margin: clamp(16px, 2.4vw, 24px) 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 10px;
}

.page-about .about-coverage-list li {
  position: relative;
  padding-left: 20px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--steel);
}

.page-about .about-coverage-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 9px;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--flame);
  box-shadow: 0 0 0 3px rgba(240, 78, 35, .14);
}

.page-about .about-figure--map {
  margin: 0;
}

/* 收束区 */
.page-about .about-cta {
  margin-top: clamp(32px, 4.6vw, 56px);
  padding: clamp(26px, 3.8vw, 44px);
  border: 1px solid var(--line-gold);
  border-radius: var(--radius-lg);
  background:
    radial-gradient(120% 140% at 100% 0%, rgba(240, 78, 35, .18), transparent 62%),
    linear-gradient(180deg, rgba(27, 39, 64, .8), rgba(11, 14, 20, .92));
}

.page-about .about-cta-title {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(20px, 2.4vw, 26px);
  line-height: 1.4;
  letter-spacing: .02em;
  color: var(--cream);
}

.page-about .about-cta-text {
  margin: 0 0 clamp(18px, 2.6vw, 26px);
  max-width: 620px;
  font-size: 15px;
  line-height: 1.85;
  color: rgba(243, 237, 228, .78);
}

.page-about .about-cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.page-about .about-top-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: clamp(24px, 3.4vw, 34px);
  padding-bottom: 4px;
  border-bottom: 1px solid var(--line-strong);
  font-size: 13px;
  letter-spacing: .08em;
  color: var(--steel);
  text-decoration: none;
  transition: color .22s var(--ease), border-color .22s var(--ease);
}

.page-about .about-top-link::before {
  content: "↑";
  font-family: var(--font-mono);
  color: var(--flame);
}

.page-about .about-top-link:hover {
  color: var(--cream);
  border-bottom-color: var(--line-gold);
}

/* ---------- 响应式 ---------- */
@media (min-width: 760px) {
  .page-about .about-hero-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-role {
    grid-template-columns: 132px minmax(0, 1fr) auto;
    grid-template-areas: "name bar num";
    gap: 16px;
  }
}

@media (min-width: 880px) {
  .page-about .about-coverage {
    grid-template-columns: minmax(0, 1fr) minmax(0, .92fr);
    align-items: center;
  }
}

@media (min-width: 1000px) {
  .page-about .about-shell {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: clamp(36px, 4.6vw, 64px);
  }

  .page-about .about-rail {
    position: sticky;
    top: 112px;
    align-self: start;
    padding-top: clamp(24px, 3.4vw, 40px);
  }

  .page-about .about-rail-title {
    margin-bottom: 18px;
  }

  .page-about .rail-list {
    flex-direction: column;
    gap: 0;
    padding: 0 0 0 20px;
    overflow: visible;
    position: relative;
  }

  .page-about .rail-list::before {
    content: "";
    position: absolute;
    left: 4px;
    top: 12px;
    bottom: 12px;
    width: 1px;
    background: linear-gradient(180deg, rgba(240, 78, 35, .5), rgba(154, 166, 188, .12));
  }

  .page-about .rail-item {
    flex: none;
  }

  .page-about .rail-item::before {
    content: "";
    position: absolute;
    left: -20px;
    top: 15px;
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--navy-2);
    border: 1px solid var(--line-strong);
    transition: background-color .3s var(--ease), border-color .3s var(--ease), box-shadow .3s var(--ease);
  }

  .page-about .rail-item.is-visible::before {
    background: var(--flame);
    border-color: var(--flame-hi);
    box-shadow: 0 0 0 4px rgba(240, 78, 35, .16);
  }

  .page-about .rail-link {
    display: block;
    width: 100%;
    padding: 8px 0;
    border: 0;
    border-radius: 0;
    background: none;
    font-size: 13.5px;
    line-height: 1.5;
    white-space: normal;
  }

  .page-about .rail-link:hover {
    color: var(--cream);
  }

  .page-about .rail-num {
    display: block;
    margin-bottom: 2px;
    letter-spacing: .16em;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .rail-link,
  .page-about .rail-item::before,
  .page-about .about-version,
  .page-about .about-top-link,
  .page-about .chapter-copy a {
    transition: none;
  }

  .page-about .about-version:hover {
    transform: none;
  }

  .page-about .about-timeline {
    scroll-behavior: auto;
  }
}