.page-about {
  --about-strong: #F1F7FA;
  --about-soft: #A9BACB;
  --about-panel: #10263B;
  --about-panel-2: #17334D;
  --about-line: rgba(79, 227, 208, 0.22);
  --about-line-soft: rgba(169, 186, 203, 0.16);
  --about-cream-line: rgba(36, 28, 23, 0.14);

  background: var(--ink-900);
  color: var(--about-soft);
  padding-bottom: 88px;
}

.page-about .about-shell {
  padding-top: 28px;
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumbs {
  margin-bottom: 26px;
}

.page-about .breadcrumbs__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: 13px;
  color: var(--about-soft);
}

.page-about .breadcrumbs__list li {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.page-about .breadcrumbs__list li + li::before {
  content: "/";
  color: rgba(169, 186, 203, 0.45);
}

.page-about .breadcrumbs__list a {
  color: var(--cyan-200);
  text-decoration: none;
}

.page-about .breadcrumbs__list a:hover {
  color: var(--cyan-400);
}

.page-about .breadcrumbs__list [aria-current="page"] {
  color: rgba(169, 186, 203, 0.7);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: 18px 0 52px;
  border-bottom: 1px solid var(--about-line-soft);
}

.page-about .about-hero__title {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(36px, 8vw, 78px);
  line-height: 1.06;
  letter-spacing: -0.02em;
  color: var(--about-strong);
  margin: 14px 0 30px;
}

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

.page-about .about-hero__lede {
  max-width: 640px;
  font-size: 16px;
  line-height: 1.78;
  color: var(--about-soft);
  margin: 0;
}

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

.page-about .about-hero__chips .rail-chip {
  border: 1px solid var(--about-line);
  color: var(--cyan-200);
  background: rgba(79, 227, 208, 0.06);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.02em;
  padding: 7px 14px;
  border-radius: var(--pill);
}

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

/* ---------- 布局：侧边索引 + 正文 ---------- */
.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 36px;
  padding-top: 40px;
}

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

.page-about .about-flow {
  display: grid;
  gap: 68px;
  min-width: 0;
}

/* ---------- 章节通用 ---------- */
.page-about .about-chapter {
  min-width: 0;
  padding: 0;
}

.page-about .chapter-open {
  margin-bottom: 26px;
}

.page-about .chapter-num {
  display: block;
  font-family: var(--font-mono);
  font-style: italic;
  font-weight: 800;
  font-size: clamp(48px, 12vw, 86px);
  line-height: 0.82;
  letter-spacing: -0.05em;
  color: rgba(79, 227, 208, 0.2);
  margin: 0 0 -14px -3px;
  user-select: none;
}

.page-about .chapter__title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(24px, 4.4vw, 40px);
  line-height: 1.2;
  letter-spacing: -0.015em;
  color: var(--about-strong);
  margin: 0;
}

.page-about .prose {
  max-width: 720px;
}

.page-about .prose p {
  font-size: 16px;
  line-height: 1.82;
  margin: 0 0 18px;
}

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

.page-about .prose a {
  color: var(--cyan-400);
  text-decoration: none;
  border-bottom: 1px solid rgba(79, 227, 208, 0.35);
}

.page-about .prose a:hover {
  color: var(--cyan-200);
}

/* ---------- 01 三条线 ---------- */
.page-about .line-cards {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .line-card {
  position: relative;
  background: var(--about-panel);
  border-radius: var(--radius-md);
  padding: 24px 22px 22px;
  border: 1px solid rgba(79, 227, 208, 0.12);
  transition: transform var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .line-card:hover {
  transform: translateY(-3px);
  border-color: rgba(79, 227, 208, 0.36);
}

.page-about .line-card .numtag {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  border-radius: 8px;
  background: rgba(255, 122, 69, 0.14);
  color: var(--orange-500);
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 700;
  margin-bottom: 14px;
}

.page-about .line-card h3 {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 800;
  color: var(--about-strong);
  margin: 0 0 10px;
  line-height: 1.35;
}

.page-about .line-card p {
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--about-soft);
  margin: 0 0 16px;
}

.page-about .line-card__link {
  display: inline-block;
  font-size: 13.5px;
  font-weight: 600;
  color: var(--cyan-400);
  text-decoration: none;
  border-bottom: 1px solid rgba(79, 227, 208, 0.4);
  padding-bottom: 2px;
}

.page-about .line-card__link::after {
  content: " →";
  transition: margin-left var(--dur) var(--ease);
}

.page-about .line-card__link:hover {
  color: var(--cyan-200);
  border-bottom-color: var(--cyan-200);
}

/* ---------- 图片块 ---------- */
.page-about .about-media {
  margin: 0 0 34px;
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--about-panel);
  border: 1px solid var(--about-line-soft);
}

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

.page-about .about-media figcaption {
  padding: 12px 18px 16px;
  font-size: 12.5px;
  letter-spacing: 0.02em;
  color: rgba(169, 186, 203, 0.72);
  border-top: 1px solid var(--about-line-soft);
}

.page-about .about-media--tall {
  margin-bottom: 26px;
}

.page-about .about-media--square {
  margin-bottom: 0;
}

/* ---------- 02 时间线 ---------- */
.page-about .timeline {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 39px;
  top: 8px;
  bottom: 12px;
  width: 1px;
  background: linear-gradient(
    to bottom,
    rgba(79, 227, 208, 0.45),
    rgba(79, 227, 208, 0.1) 70%,
    rgba(79, 227, 208, 0) 100%
  );
}

.page-about .timeline__item {
  position: relative;
  display: grid;
  grid-template-columns: 78px minmax(0, 1fr);
  gap: 14px;
  padding-bottom: 30px;
}

.page-about .timeline__item:last-child {
  padding-bottom: 0;
}

.page-about .timeline__marker {
  position: relative;
  padding-top: 2px;
}

.page-about .timeline__year {
  display: block;
  font-size: 13.5px;
  font-weight: 600;
  letter-spacing: -0.01em;
  line-height: 1.35;
  color: var(--cyan-400);
  white-space: nowrap;
}

.page-about .timeline__body {
  position: relative;
  padding: 0 0 0 2px;
}

.page-about .timeline__body::before {
  content: "";
  position: absolute;
  left: -15px;
  top: 7px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--ink-900);
  border: 2px solid var(--cyan-400);
}

.page-about .timeline__title {
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 700;
  color: var(--about-strong);
  margin: 0 0 8px;
  line-height: 1.4;
}

.page-about .timeline__body p {
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--about-soft);
  margin: 0;
}

/* ---------- 03 服务网络（奶油底） ---------- */
.page-about .about-chapter--cream {
  background: var(--cream-100);
  color: var(--brown-900);
  border-radius: var(--radius-lg);
  padding: 34px 22px;
  margin-left: -22px;
  margin-right: -22px;
}

.page-about .about-chapter--cream .chapter__title {
  color: var(--brown-900);
}

.page-about .about-chapter--cream .chapter-num {
  color: rgba(180, 83, 31, 0.28);
}

.page-about .about-chapter--cream .prose p {
  color: rgba(36, 28, 23, 0.82);
}

.page-about .about-chapter--cream .prose a {
  color: var(--orange-deep);
  border-bottom-color: rgba(180, 83, 31, 0.4);
}

.page-about .about-chapter--cream .about-media {
  background: var(--cream-200);
  border-color: var(--about-cream-line);
}

.page-about .about-chapter--cream .about-media figcaption {
  color: rgba(36, 28, 23, 0.6);
  border-top-color: var(--about-cream-line);
}

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

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

/* 网络横向滚动条 */
.page-about .net-strip {
  margin-top: 30px;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
  padding-bottom: 10px;
}

.page-about .net-strip__list {
  display: flex;
  gap: 10px;
  list-style: none;
  margin: 0;
  padding: 0;
  min-width: max-content;
}

.page-about .netnode {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 15px;
  border-radius: var(--pill);
  background: rgba(36, 28, 23, 0.06);
  border: 1px solid var(--about-cream-line);
  font-size: 13.5px;
  color: rgba(36, 28, 23, 0.78);
  white-space: nowrap;
}

.page-about .netnode__label {
  font-weight: 600;
}

.page-about .netnode--core {
  background: rgba(255, 122, 69, 0.14);
  border-color: rgba(180, 83, 31, 0.34);
  color: var(--brown-900);
}

.page-about .netnode__tag {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--orange-deep);
}

.page-about .netnode--out {
  background: transparent;
  border-style: dashed;
  border-color: rgba(36, 28, 23, 0.28);
  color: rgba(36, 28, 23, 0.66);
}

/* ---------- 04 团队 ---------- */
.page-about .role-lead {
  display: flex;
  align-items: baseline;
  gap: 10px;
  margin-bottom: 10px;
}

.page-about .role-lead__num {
  font-family: var(--font-mono);
  font-size: clamp(52px, 12vw, 76px);
  font-weight: 800;
  line-height: 0.9;
  color: var(--cyan-400);
  letter-spacing: -0.04em;
}

.page-about .role-lead__unit {
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 700;
  color: var(--about-strong);
}

.page-about .role-lead__copy {
  font-size: 15px;
  line-height: 1.78;
  color: var(--about-soft);
  margin: 0 0 24px;
  max-width: 560px;
}

.page-about .role-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 2px;
}

.page-about .role-item {
  padding: 18px 0;
  border-top: 1px solid var(--about-line-soft);
}

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

.page-about .role-item h3 {
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 700;
  color: var(--cyan-200);
  margin: 0 0 7px;
  letter-spacing: 0.01em;
}

.page-about .role-item p {
  font-size: 14.5px;
  line-height: 1.76;
  color: var(--about-soft);
  margin: 0;
}

/* ---------- 05 资质 ---------- */
.page-about .cred-grid {
  display: grid;
  gap: 12px;
  margin-bottom: 22px;
}

.page-about .cred-card {
  display: grid;
  gap: 6px;
  padding: 18px 20px;
  background: var(--cream-200);
  border-radius: var(--radius-sm);
  border: 1px solid var(--about-cream-line);
}

.page-about .cred-card__k {
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: rgba(36, 28, 23, 0.55);
}

.page-about .cred-card__v {
  font-size: 16px;
  font-weight: 600;
  color: var(--brown-900);
  text-decoration: none;
  word-break: break-word;
}

.page-about a.cred-card__v {
  color: var(--orange-deep);
}

.page-about a.cred-card__v:hover {
  color: var(--brown-900);
}

.page-about .cred-note,
.page-about .cred-more {
  font-size: 14px;
  line-height: 1.78;
  color: rgba(36, 28, 23, 0.72);
  margin: 0 0 12px;
  max-width: 720px;
}

.page-about .cred-more {
  margin-bottom: 0;
}

.page-about .cred-note a,
.page-about .cred-more a {
  color: var(--orange-deep);
  text-decoration: none;
  border-bottom: 1px solid rgba(180, 83, 31, 0.4);
}

.page-about .cred-note a:hover,
.page-about .cred-more a:hover {
  color: var(--brown-900);
}

/* ---------- 06 落地协作 ---------- */
.page-about .partner-band {
  display: grid;
  gap: 14px;
  margin-top: 28px;
}

.page-about .partner-band__item {
  position: relative;
  padding: 22px 20px 20px;
  border-radius: var(--radius-md);
  background: linear-gradient(160deg, rgba(79, 227, 208, 0.09), rgba(11, 27, 43, 0) 62%);
  border: 1px solid var(--about-line-soft);
}

.page-about .partner-band__k {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--amber-300);
  margin-bottom: 10px;
}

.page-about .partner-band__item h3 {
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 700;
  color: var(--about-strong);
  margin: 0 0 8px;
}

.page-about .partner-band__item p {
  font-size: 14px;
  line-height: 1.74;
  color: var(--about-soft);
  margin: 0;
}

/* ---------- 收束 ---------- */
.page-about .about-closing {
  padding: 32px 24px;
  border-radius: var(--radius-lg);
  background: var(--about-panel-2);
  border: 1px solid var(--about-line);
}

.page-about .about-closing__text {
  font-family: var(--font-display);
  font-size: clamp(19px, 3.4vw, 26px);
  font-weight: 700;
  line-height: 1.55;
  color: var(--about-strong);
  margin: 0 0 22px;
  max-width: 640px;
}

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

/* ---------- 底部章节导航 ---------- */
.page-about .end-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 18px;
  padding-top: 24px;
  border-top: 1px solid var(--about-line-soft);
}

.page-about .end-nav a {
  font-size: 13.5px;
  color: var(--about-soft);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  padding-bottom: 2px;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .end-nav a:hover {
  color: var(--cyan-200);
  border-bottom-color: var(--cyan-400);
}

.page-about .end-nav__top {
  margin-left: auto;
  color: var(--cyan-400) !important;
}

/* ---------- 侧边索引（桌面端） ---------- */
@media (min-width: 1000px) {
  .page-about .about-shell {
    padding-top: 40px;
  }

  .page-about .about-hero {
    padding: 26px 0 64px;
  }

  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1fr) 260px;
    align-items: end;
    gap: 40px;
  }

  .page-about .about-hero__note {
    display: block;
    position: absolute;
    right: 6px;
    top: 40px;
    color: rgba(79, 227, 208, 0.5);
    letter-spacing: 0.22em;
  }

  .page-about .about-layout {
    grid-template-columns: 176px minmax(0, 1fr);
    gap: 52px;
    padding-top: 56px;
  }

  .page-about .about-index {
    display: block;
    position: sticky;
    top: calc(var(--nav-h) + 28px);
    align-self: start;
    padding-right: 8px;
  }

  .page-about .about-index .side-index__title {
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: rgba(169, 186, 203, 0.62);
    margin: 0 0 16px;
  }

  .page-about .about-index .side-index__link {
    display: block;
    position: relative;
    padding: 8px 0 8px 16px;
    font-size: 13.5px;
    color: var(--about-soft);
    text-decoration: none;
    border-left: 1px solid var(--about-line-soft);
    transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
  }

  .page-about .about-index .side-index__link::before {
    content: "";
    position: absolute;
    left: -1px;
    top: 50%;
    transform: translateY(-50%) scaleY(0);
    width: 2px;
    height: 62%;
    background: var(--cyan-400);
    transform-origin: center;
    transition: transform var(--dur) var(--ease);
  }

  .page-about .about-index .side-index__link:hover {
    color: var(--cyan-200);
  }

  .page-about .about-index .side-index__link[aria-current="true"] {
    color: var(--cyan-400);
    border-left-color: var(--cyan-400);
  }

  .page-about .about-index .side-index__link[aria-current="true"]::before {
    transform: translateY(-50%) scaleY(1);
  }

  .page-about .about-chapter--cream {
    padding: 48px 44px;
    margin-left: 0;
    margin-right: 0;
  }

  .page-about .about-split {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: 40px;
    align-items: start;
  }

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

  .page-about .about-split--reverse .about-media {
    order: -1;
  }

  .page-about .line-cards {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 16px;
  }

  .page-about .timeline__item {
    grid-template-columns: 118px minmax(0, 1fr);
    gap: 22px;
    padding-bottom: 36px;
  }

  .page-about .timeline::before {
    left: 59px;
  }

  .page-about .timeline__body::before {
    left: -18px;
  }

  .page-about .timeline__year {
    font-size: 15px;
  }

  .page-about .cred-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 14px;
  }

  .page-about .partner-band {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
  }

  .page-about .about-closing {
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: 32px;
    padding: 40px 44px;
  }

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

  .page-about .about-closing__actions {
    justify-content: flex-end;
  }
}

@media (min-width: 1320px) {
  .page-about .about-layout {
    grid-template-columns: 200px minmax(0, 1fr);
    gap: 64px;
  }
}