.page-about {
  --about-pad: clamp(20px, 4vw, 44px);
  --about-gap: clamp(26px, 4vw, 56px);
  --about-line: rgba(30, 74, 107, .9);
  background:
    radial-gradient(1100px 620px at 90% -12%, rgba(30, 74, 107, .5), transparent 62%),
    var(--deep-sea);
  color: var(--cream);
  font-family: var(--font-body);
}

.page-about .container {
  width: 100%;
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  padding: clamp(22px, 4vw, 44px) 0 clamp(34px, 5vw, 72px);
}

.page-about .hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(26px, 4vw, 52px);
  margin-top: clamp(20px, 3vw, 34px);
}

.page-about .hero-copy {
  min-width: 0;
}

.page-about .about-hero h1 {
  margin: 12px 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(30px, 5vw, 52px);
  line-height: 1.14;
  letter-spacing: -0.012em;
  color: var(--cream);
}

.page-about .about-hero .lede {
  margin: 18px 0 0;
  max-width: 46ch;
  font-size: clamp(16px, 1.9vw, 18px);
  line-height: 1.82;
  color: rgba(242, 236, 224, .82);
}

.page-about .hero-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px 22px;
  margin-top: 26px;
}

.page-about .hero-facts {
  list-style: none;
  margin: 34px 0 0;
  padding: 22px 0 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px 20px;
  border-top: 1px dashed rgba(138, 151, 163, .32);
}

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

.page-about .hero-fact-num {
  font-size: clamp(20px, 2.6vw, 26px);
  font-weight: 700;
  color: var(--amber);
  letter-spacing: .02em;
}

.page-about .hero-fact-label {
  font-size: 14px;
  line-height: 1.6;
  color: var(--rock);
}

.page-about .hero-media {
  aspect-ratio: 4 / 3;
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.page-about .hero-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.page-about .hero-media .media-caption {
  font-size: 13px;
  line-height: 1.7;
}

@media (min-width: 900px) {
  .page-about .hero-grid {
    grid-template-columns: minmax(0, 1.06fr) minmax(0, .94fr);
    align-items: center;
  }
  .page-about .hero-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ---------- 主体骨架：编号轨道 + 正文 ---------- */

.page-about .about-body {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 4vw, 48px);
  padding-bottom: clamp(48px, 7vw, 96px);
}

.page-about .chapter-rail {
  display: none;
}

.page-about .rail-caption {
  margin: 0 0 12px;
  font-size: 11px;
  letter-spacing: .22em;
  color: var(--rock);
}

.page-about .chapter-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 2px;
  border-left: 1px solid rgba(138, 151, 163, .26);
}

.page-about .chapter-link {
  display: grid;
  grid-template-columns: auto 1fr;
  align-items: baseline;
  gap: 10px;
  margin-left: -1px;
  padding: 9px 10px 9px 15px;
  border-left: 2px solid transparent;
  text-decoration: none;
  color: var(--rock);
  font-size: 14px;
  line-height: 1.5;
  transition: color .24s var(--ease), border-color .24s var(--ease), background-color .24s var(--ease);
}

.page-about .chapter-link:hover,
.page-about .chapter-link:focus-visible {
  color: var(--cream);
  border-left-color: var(--amber);
  background-color: rgba(18, 58, 90, .6);
}

.page-about .chapter-num {
  font-size: 11px;
  letter-spacing: .06em;
  color: var(--amber);
}

.page-about .about-sections {
  min-width: 0;
  display: grid;
  gap: clamp(46px, 7vw, 88px);
}

@media (min-width: 1024px) {
  .page-about .about-body {
    grid-template-columns: 186px minmax(0, 1fr);
    align-items: start;
  }
  .page-about .chapter-rail {
    display: block;
    position: sticky;
    top: 148px;
  }
}

/* ---------- 章节通用 ---------- */

.page-about .about-section {
  scroll-margin-top: 150px;
}

.page-about .about-head {
  display: grid;
  grid-template-columns: auto 1fr;
  align-items: baseline;
  gap: 14px;
  margin-bottom: 16px;
}

.page-about .about-num {
  font-size: clamp(22px, 3vw, 32px);
  font-weight: 700;
  letter-spacing: .06em;
  color: var(--amber);
  transition: color .28s var(--ease);
}

.page-about .about-section:target .about-num {
  color: var(--coral);
}

.page-about .about-title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(22px, 3.4vw, 32px);
  line-height: 1.24;
  letter-spacing: -0.008em;
  color: var(--cream);
}

.page-about .about-lede {
  margin: 0;
  max-width: 62ch;
  font-size: clamp(16px, 1.85vw, 17.5px);
  line-height: 1.85;
  color: rgba(242, 236, 224, .8);
}

/* ---------- 01 人群 ---------- */

.page-about .crowd-list {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: grid;
  gap: 20px;
}

.page-about .crowd-item {
  position: relative;
  padding-left: 20px;
}

.page-about .crowd-item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--celadon);
  box-shadow: 0 0 0 4px rgba(82, 160, 142, .14);
}

.page-about .crowd-role {
  margin: 0 0 5px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 16.5px;
  line-height: 1.5;
  color: var(--cream);
}

.page-about .crowd-item p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--rock);
}

@media (min-width: 720px) {
  .page-about .crowd-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 22px 32px;
  }
}

/* ---------- 02 时间线 ---------- */

.page-about .tl-list {
  list-style: none;
  position: relative;
  margin: 30px 0 0;
  padding: 0 0 0 24px;
  display: grid;
  gap: 32px;
}

.page-about .tl-list::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: repeating-linear-gradient(180deg, rgba(232, 169, 60, .5) 0 6px, transparent 6px 14px);
}

.page-about .tl-node {
  position: relative;
  min-width: 0;
}

.page-about .tl-node::before {
  content: "";
  position: absolute;
  left: -24px;
  top: 5px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--deep-sea);
  border: 2px solid var(--amber);
  box-shadow: 0 0 0 4px rgba(232, 169, 60, .12);
}

.page-about .tl-year {
  display: block;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: .08em;
  color: var(--amber);
}

.page-about .tl-heading {
  margin: 6px 0 6px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 17px;
  line-height: 1.5;
  color: var(--cream);
}

.page-about .tl-brief {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: rgba(242, 236, 224, .76);
}

.page-about .tl-more {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--rock);
}

@media (hover: hover) {
  .page-about .tl-more {
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    transition: max-height .32s var(--ease), opacity .32s var(--ease), margin-top .32s var(--ease);
  }
  .page-about .tl-node:hover .tl-more,
  .page-about .tl-node:focus-within .tl-more,
  .page-about .tl-node:focus .tl-more {
    max-height: 160px;
    opacity: 1;
    margin-top: 8px;
  }
}

@media (min-width: 900px) {
  .page-about .tl-list {
    grid-template-columns: repeat(5, minmax(0, 1fr));
    gap: 22px;
    padding: 0;
  }
  .page-about .tl-list::before {
    display: none;
  }
  .page-about .tl-node {
    padding-top: 30px;
    border-top: 1px solid rgba(30, 74, 107, .9);
  }
  .page-about .tl-node::before {
    left: 0;
    top: -6px;
    box-shadow: 0 0 0 5px rgba(10, 31, 51, .95), 0 0 0 7px rgba(232, 169, 60, .18);
  }
  .page-about .tl-node::after {
    content: "";
    position: absolute;
    top: -1px;
    left: 14px;
    right: -22px;
    height: 1px;
    background: repeating-linear-gradient(90deg, rgba(232, 169, 60, .45) 0 6px, transparent 6px 14px);
  }
  .page-about .tl-node:last-child::after {
    display: none;
  }
}

.page-about .tl-node:focus-visible {
  outline: 2px solid var(--coral);
  outline-offset: 8px;
  border-radius: 4px;
}

/* ---------- 03 团队 ---------- */

.page-about .crew-media {
  aspect-ratio: 3 / 2;
  margin: 30px 0 0;
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.page-about .crew-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.page-about .crew-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  margin-top: 26px;
}

.page-about .crew-card {
  background: linear-gradient(180deg, rgba(18, 58, 90, .9), rgba(10, 31, 51, .92));
  border: 1px solid var(--about-line);
  border-radius: var(--radius);
  padding: 20px 20px 14px;
  transition: transform .28s var(--ease), border-color .28s var(--ease), box-shadow .28s var(--ease);
}

.page-about .crew-card:hover {
  transform: translateY(-3px);
  border-color: rgba(232, 169, 60, .6);
  box-shadow: var(--shadow-card);
}

.page-about .crew-head {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding-bottom: 10px;
  border-bottom: 1px solid rgba(30, 74, 107, .85);
}

.page-about .crew-code {
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--celadon);
}

.page-about .crew-role {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 17px;
  color: var(--cream);
}

.page-about .crew-brief {
  margin: 12px 0 0;
  font-size: 15px;
  line-height: 1.8;
  color: rgba(242, 236, 224, .78);
}

.page-about .crew-detail {
  margin-top: 10px;
  border-top: 1px dashed rgba(138, 151, 163, .28);
}

.page-about .crew-detail summary {
  cursor: pointer;
  list-style: none;
  padding: 10px 0 6px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .06em;
  color: var(--amber);
}

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

.page-about .crew-detail summary::after {
  content: "  +";
}

.page-about .crew-detail[open] summary::after {
  content: "  −";
}

.page-about .crew-detail summary:focus-visible {
  outline: 2px solid var(--coral);
  outline-offset: 2px;
}

.page-about .crew-list {
  list-style: none;
  margin: 0 0 10px;
  padding: 0;
  display: grid;
  gap: 8px;
}

.page-about .crew-list li {
  position: relative;
  padding-left: 16px;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--rock);
}

.page-about .crew-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 9px;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--amber);
}

@media (min-width: 760px) {
  .page-about .crew-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px;
  }
}

/* ---------- 04 服务主张 ---------- */

.page-about .claims-panel {
  margin-top: 30px;
  padding: clamp(24px, 4vw, 46px);
  background: var(--cream);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lift);
}

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

.page-about .claim-item {
  border-left: 3px solid var(--clay);
  padding: 2px 0 4px 18px;
}

.page-about .claim-idx {
  display: block;
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--clay);
}

.page-about .claim-title {
  margin: 6px 0 8px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 18px;
  line-height: 1.4;
  color: var(--deep-sea);
}

.page-about .claim-item p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.85;
  color: #2f3f4c;
}

@media (min-width: 820px) {
  .page-about .claim-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 32px 40px;
  }
}

/* ---------- 05 来源 ---------- */

.page-about .source-list {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
  display: grid;
  gap: 24px;
}

.page-about .source-item {
  display: grid;
  grid-template-columns: 54px minmax(0, 1fr);
  gap: 16px;
  padding-bottom: 22px;
  border-bottom: 1px dashed rgba(138, 151, 163, .3);
}

.page-about .source-item:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

.page-about .source-idx {
  font-size: 24px;
  font-weight: 700;
  letter-spacing: .04em;
  color: rgba(232, 169, 60, .72);
  line-height: 1.2;
}

.page-about .source-title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 17.5px;
  line-height: 1.45;
  color: var(--cream);
}

.page-about .source-body p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.85;
  color: rgba(242, 236, 224, .78);
}

.page-about .source-note {
  margin-top: 28px;
  padding: 20px 22px;
  background: rgba(18, 58, 90, .62);
  border: 1px solid var(--about-line);
  border-radius: var(--radius);
}

.page-about .source-note-label {
  margin: 0 0 8px;
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--celadon);
}

.page-about .source-note p:last-child {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: rgba(242, 236, 224, .8);
}

/* ---------- 06 合作 ---------- */

.page-about .partner-media {
  aspect-ratio: 12 / 7;
  margin: 30px 0 0;
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.page-about .partner-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.page-about .partner-grid {
  margin-top: 30px;
  display: grid;
  grid-template-columns: 1fr;
  gap: 2px;
}

.page-about .partner-block {
  padding: 22px 0;
  border-top: 1px solid rgba(30, 74, 107, .85);
}

.page-about .partner-title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 17px;
  color: var(--amber);
}

.page-about .partner-block p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.85;
  color: rgba(242, 236, 224, .78);
}

@media (min-width: 820px) {
  .page-about .partner-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: 40px;
  }
}

/* ---------- 结尾行动 ---------- */

.page-about .about-cta {
  margin-top: clamp(10px, 2vw, 24px);
  padding: clamp(26px, 4vw, 40px);
  background:
    linear-gradient(135deg, rgba(255, 107, 61, .16), rgba(18, 58, 90, .72) 62%),
    var(--night-blue);
  border: 1px solid rgba(255, 107, 61, .34);
  border-radius: var(--radius-lg);
}

.page-about .cta-title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(20px, 3vw, 28px);
  line-height: 1.35;
  color: var(--cream);
}

.page-about .cta-text {
  margin: 14px 0 0;
  max-width: 58ch;
  font-size: 16px;
  line-height: 1.85;
  color: rgba(242, 236, 224, .84);
}

.page-about .cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 24px;
}

/* ---------- 图片通用兜底 ---------- */

.page-about img {
  max-width: 100%;
  height: auto;
}

/* ---------- 动效降级 ---------- */

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition-duration: .01ms !important;
    animation-duration: .01ms !important;
  }
}