.page-about {
  --about-line: rgba(42, 74, 107, .55);
  --about-glow: rgba(25, 211, 197, .18);
  background: var(--ink);
  color: var(--white);
  padding-bottom: 40px;
}

.page-about .container {
  width: 100%;
  max-width: var(--shell-w);
  margin: 0 auto;
  padding: 0 20px;
  box-sizing: border-box;
}

/* ---------- 首屏 ---------- */
.page-about .breadcrumb {
  padding: 18px 0 4px;
}

.page-about .breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: 13px;
  color: var(--silver);
}

.page-about .breadcrumb__link {
  color: var(--silver);
  text-decoration: none;
  border-bottom: 1px dashed var(--about-line);
}

.page-about .breadcrumb__link:hover {
  color: var(--cyan);
}

.page-about .about-hero {
  position: relative;
  padding: 24px 0 46px;
  overflow: hidden;
  border-bottom: 1px solid var(--about-line);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, var(--about-line) 1px, transparent 1px),
    linear-gradient(to bottom, var(--about-line) 1px, transparent 1px);
  background-size: 64px 64px;
  opacity: .22;
  pointer-events: none;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  top: -140px;
  right: -120px;
  width: 340px;
  height: 340px;
  border-radius: 50%;
  background: radial-gradient(circle, var(--about-glow) 0%, transparent 68%);
  pointer-events: none;
}

.page-about .about-hero__grid {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 26px;
}

.page-about .eyebrow {
  display: inline-block;
  margin: 0;
  padding: 5px 14px;
  border: 1px solid var(--about-line);
  border-radius: var(--radius-pill);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--cyan);
  background: rgba(16, 42, 67, .7);
}

.page-about .about-hero h1 {
  margin: 14px 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(30px, 7.4vw, 56px);
  line-height: 1.14;
  letter-spacing: .005em;
  color: var(--white);
}

.page-about .about-hero__intro {
  margin: 16px 0 0;
  max-width: 46em;
  font-size: 16px;
  line-height: 1.78;
  color: var(--mist);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 22px;
}

.page-about .btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 11px 20px;
  border-radius: var(--radius-pill);
  border: 1px solid transparent;
  font-size: 15px;
  font-weight: 700;
  text-decoration: none;
  cursor: pointer;
  transition: transform .25s var(--ease), background-color .25s var(--ease), border-color .25s var(--ease), color .25s var(--ease);
}

.page-about .btn--primary {
  background: var(--orange);
  color: #1a0d05;
}

.page-about .btn--primary:hover {
  background: var(--amber);
  transform: translateY(-2px);
}

.page-about .btn--ghost {
  border-color: var(--cyan);
  color: var(--cyan);
  background: transparent;
}

.page-about .btn--ghost:hover {
  background: rgba(25, 211, 197, .12);
  transform: translateY(-2px);
}

.page-about .btn--quiet {
  border-color: var(--about-line);
  color: var(--mist);
  background: transparent;
}

.page-about .btn--quiet:hover {
  border-color: var(--teal);
  color: var(--white);
}

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

.page-about .figure__frame {
  overflow: hidden;
  border: 1px solid var(--about-line);
  border-radius: var(--radius-lg);
  background: var(--ink-2);
}

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

.page-about .figure__caption {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--silver);
}

.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin: 0;
}

.page-about .about-stat {
  padding: 14px 16px;
  border: 1px solid var(--about-line);
  border-radius: var(--radius-md);
  background: linear-gradient(160deg, var(--ink-2) 0%, var(--ink) 100%);
}

.page-about .about-stat dt {
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--silver);
}

.page-about .about-stat dd {
  margin: 6px 0 0;
  font-family: var(--font-mono);
  font-size: 24px;
  font-weight: 700;
  color: var(--cyan);
}

/* ---------- 章节目录 ---------- */
.page-about .about-toc {
  position: sticky;
  top: var(--header-h);
  z-index: 6;
  padding: 10px 0;
  background: rgba(11, 27, 43, .94);
  border-bottom: 1px solid var(--about-line);
}

.page-about .about-toc__inner {
  display: flex;
  align-items: center;
  gap: 14px;
  overflow-x: auto;
  scrollbar-width: none;
}

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

.page-about .toc__title {
  flex: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--silver);
}

.page-about .toc__list {
  display: flex;
  flex: none;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .toc-link {
  display: inline-block;
  padding: 6px 14px;
  border: 1px solid var(--about-line);
  border-radius: var(--radius-pill);
  font-size: 13px;
  color: var(--mist);
  text-decoration: none;
  white-space: nowrap;
  transition: color .25s var(--ease), border-color .25s var(--ease), background-color .25s var(--ease);
}

.page-about .toc-link:hover,
.page-about .toc-link.is-in {
  color: var(--white);
  border-color: var(--orange);
  background: rgba(255, 106, 42, .14);
}

/* ---------- 通用章节 ---------- */
.page-about .section {
  position: relative;
  padding: 52px 0;
}

.page-about .section--panel {
  background: linear-gradient(180deg, var(--ink) 0%, var(--ink-3) 50%, var(--ink) 100%);
  border-top: 1px solid var(--about-line);
  border-bottom: 1px solid var(--about-line);
}

.page-about .section-head {
  margin-bottom: 26px;
}

.page-about .section-head__num {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .18em;
  color: var(--orange);
}

.page-about .section-title {
  margin: 8px 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(23px, 5.4vw, 38px);
  line-height: 1.2;
  color: var(--white);
}

.page-about .section-sub {
  margin: 12px 0 0;
  max-width: 52em;
  font-size: 15px;
  line-height: 1.8;
  color: var(--mist);
}

/* ---------- 时间轴 ---------- */
.page-about .about-years {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  margin: 0 0 26px;
  padding: 0;
}

.page-about .about-years__link {
  display: inline-block;
  padding: 7px 16px;
  border: 1px solid var(--about-line);
  border-radius: var(--radius-pill);
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 700;
  color: var(--cyan);
  text-decoration: none;
  transition: border-color .25s var(--ease), background-color .25s var(--ease), color .25s var(--ease);
}

.page-about .about-years__link:hover {
  border-color: var(--cyan);
  background: rgba(25, 211, 197, .12);
  color: var(--white);
}

.page-about .about-track {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-track__item {
  position: relative;
  padding: 0 0 34px 34px;
}

.page-about .about-track__item::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 8px;
  bottom: 0;
  width: 1px;
  background: linear-gradient(180deg, var(--line) 0%, var(--teal) 100%);
}

.page-about .about-track__item::after {
  content: "";
  position: absolute;
  left: 0;
  top: 8px;
  width: 13px;
  height: 13px;
  border-radius: 50%;
  background: var(--ink);
  border: 2px solid var(--cyan);
}

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

.page-about .about-track__item:last-child::before {
  display: none;
}

.page-about .about-track__year {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(26px, 6.4vw, 36px);
  font-weight: 700;
  line-height: 1;
  color: var(--cyan);
  letter-spacing: .02em;
}

.page-about .about-track__mark {
  display: inline-block;
  margin-left: 10px;
  padding: 3px 10px;
  border-radius: var(--radius-pill);
  font-family: var(--font-body);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: .06em;
  color: var(--silver);
  border: 1px solid var(--about-line);
  vertical-align: middle;
}

.page-about .about-track__body {
  margin-top: 12px;
  padding: 18px 18px 20px;
  border: 1px solid var(--about-line);
  border-radius: var(--radius-lg);
  background: linear-gradient(165deg, var(--ink-2) 0%, rgba(11, 27, 43, .6) 100%);
}

.page-about .about-track__body h3 {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 20px;
  line-height: 1.35;
  color: var(--white);
}

.page-about .about-track__body p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--mist);
}

.page-about .tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  margin: 14px 0 0;
  padding: 0;
}

.page-about .tag {
  display: inline-block;
  padding: 4px 12px;
  border-radius: var(--radius-pill);
  font-size: 12px;
  letter-spacing: .04em;
}

.page-about .tag--plain {
  border: 1px solid var(--about-line);
  color: var(--mist);
  background: rgba(16, 42, 67, .6);
}

.page-about .tag--orange {
  border: 1px solid rgba(255, 106, 42, .55);
  color: var(--orange);
  background: rgba(255, 106, 42, .1);
}

/* ---------- 三组协作 ---------- */
.page-about .about-teams {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
}

.page-about .card {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 22px 20px;
  border: 1px solid var(--about-line);
  border-radius: var(--radius-lg);
  background: linear-gradient(165deg, var(--ink-2) 0%, var(--ink) 72%);
  transition: transform .3s var(--ease), border-color .3s var(--ease), box-shadow .3s var(--ease);
}

.page-about .card:hover {
  transform: translateY(-4px);
  border-color: rgba(25, 211, 197, .5);
  box-shadow: 0 18px 40px rgba(0, 0, 0, .34);
}

.page-about .about-team-card__index {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .2em;
  color: var(--orange);
}

.page-about .about-team-card__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 20px;
  line-height: 1.35;
  color: var(--white);
}

.page-about .about-team-card__body {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--mist);
}

.page-about .about-team-card__meta {
  margin: auto 0 0;
  padding-top: 12px;
  border-top: 1px dashed var(--about-line);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--cyan);
}

.page-about .about-teams__figure {
  margin-top: 30px;
}

/* ---------- 新版同步 ---------- */
.page-about .about-sync__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
}

.page-about .about-sync__lead p {
  margin: 14px 0 0;
  font-size: 15px;
  line-height: 1.82;
  color: var(--mist);
}

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

.page-about .about-sync__panel {
  padding: 22px 20px;
  border: 1px solid var(--about-line);
  border-radius: var(--radius-lg);
  background: linear-gradient(200deg, rgba(16, 42, 67, .92) 0%, rgba(11, 27, 43, .9) 100%);
}

.page-about .about-sync__panel-title {
  margin: 0 0 16px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .16em;
  color: var(--cyan);
}

.page-about .about-sync__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .about-sync__item {
  display: grid;
  grid-template-columns: 34px 1fr;
  gap: 10px;
  align-items: start;
  padding-bottom: 12px;
  border-bottom: 1px dashed var(--about-line);
}

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

.page-about .about-sync__num {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--orange);
  padding-top: 2px;
}

.page-about .about-sync__text {
  font-size: 14px;
  line-height: 1.72;
  color: var(--mist);
}

/* ---------- 天津服务节点 ---------- */
.page-about .about-node__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 26px;
}

.page-about .about-node__body p {
  margin: 14px 0 0;
  font-size: 15px;
  line-height: 1.82;
  color: var(--mist);
}

.page-about .about-contact {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-contact__item {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  padding: 12px 14px;
  border: 1px solid var(--about-line);
  border-radius: var(--radius-md);
  background: rgba(16, 42, 67, .6);
}

.page-about .about-contact__label {
  flex: none;
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--silver);
}

.page-about .about-contact__value {
  flex: 1 1 180px;
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--white);
  word-break: break-all;
}

.page-about .copy-btn {
  flex: none;
  padding: 5px 12px;
  border: 1px solid var(--cyan);
  border-radius: var(--radius-pill);
  background: transparent;
  color: var(--cyan);
  font-size: 12px;
  font-family: var(--font-body);
  cursor: pointer;
  transition: background-color .25s var(--ease), color .25s var(--ease);
}

.page-about .copy-btn:hover {
  background: rgba(25, 211, 197, .16);
  color: var(--white);
}

.page-about .about-node__hint {
  margin: 18px 0 0;
  padding-left: 14px;
  border-left: 2px solid var(--cyan);
  font-size: 13px;
  line-height: 1.75;
  color: var(--silver);
}

/* ---------- 荣誉 ---------- */
.page-about .about-milestones__list {
  display: grid;
  gap: 12px;
}

.page-about .about-milestone {
  border: 1px solid var(--about-line);
  border-radius: var(--radius-lg);
  background: linear-gradient(160deg, var(--ink-2) 0%, var(--ink) 78%);
  overflow: hidden;
}

.page-about .about-milestone__summary {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 16px 18px;
  cursor: pointer;
  list-style: none;
}

.page-about .about-milestone__summary::-webkit-details-marker {
  display: none;
}

.page-about .about-milestone__year {
  flex: none;
  font-family: var(--font-mono);
  font-size: 18px;
  font-weight: 700;
  color: var(--amber);
  min-width: 62px;
}

.page-about .about-milestone__name {
  flex: 1 1 auto;
  font-size: 15px;
  font-weight: 700;
  line-height: 1.5;
  color: var(--white);
}

.page-about .about-milestone__toggle {
  flex: none;
  position: relative;
  width: 18px;
  height: 18px;
}

.page-about .about-milestone__toggle::before,
.page-about .about-milestone__toggle::after {
  content: "";
  position: absolute;
  background: var(--cyan);
  border-radius: 2px;
}

.page-about .about-milestone__toggle::before {
  left: 0;
  top: 8px;
  width: 18px;
  height: 2px;
}

.page-about .about-milestone__toggle::after {
  left: 8px;
  top: 0;
  width: 2px;
  height: 18px;
  transition: transform .3s var(--ease);
}

.page-about .about-milestone[open] .about-milestone__toggle::after {
  transform: scaleY(0);
}

.page-about .about-milestone__panel {
  padding: 0 18px 18px 18px;
  border-top: 1px dashed var(--about-line);
}

.page-about .about-milestone__panel p {
  margin: 14px 0 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--mist);
}

/* ---------- 下一阶段 ---------- */
.page-about .about-next__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 26px;
}

.page-about .about-next__body p {
  margin: 14px 0 0;
  font-size: 15px;
  line-height: 1.82;
  color: var(--mist);
}

.page-about .about-next__cta {
  padding: 22px 20px;
  border: 1px solid var(--about-line);
  border-radius: var(--radius-lg);
  background:
    radial-gradient(circle at 100% 0%, rgba(255, 106, 42, .16) 0%, transparent 62%),
    linear-gradient(160deg, var(--ink-2) 0%, var(--ink) 80%);
}

.page-about .about-next__cta-title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 20px;
  line-height: 1.4;
  color: var(--white);
}

.page-about .about-next__cta-list {
  list-style: none;
  margin: 18px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-next__cta-list .btn {
  width: 100%;
}

/* ---------- 平板 ---------- */
@media (min-width: 700px) {
  .page-about .container {
    padding: 0 32px;
  }

  .page-about .about-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

  .page-about .about-track__item {
    display: grid;
    grid-template-columns: 104px 1fr;
    gap: 0 26px;
    padding-left: 34px;
    padding-bottom: 42px;
  }

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

  .page-about .about-track__mark {
    display: block;
    margin: 10px 0 0;
    width: fit-content;
  }
}

/* ---------- 桌面 ---------- */
@media (min-width: 1000px) {
  .page-about .section {
    padding: 72px 0;
  }

  .page-about .about-hero {
    padding: 34px 0 64px;
  }

  .page-about .about-hero__grid {
    grid-template-columns: repeat(12, minmax(0, 1fr));
    gap: 24px 28px;
    align-items: start;
  }

  .page-about .about-hero__lead {
    grid-column: 1 / span 7;
  }

  .page-about .about-hero__figure {
    grid-column: 8 / span 5;
    margin-top: 8px;
  }

  .page-about .about-hero__stats {
    grid-column: 1 / span 12;
    margin-top: 8px;
  }

  .page-about .about-teams {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 20px;
  }

  .page-about .about-teams > .about-team-card:nth-child(2) {
    margin-top: 30px;
  }

  .page-about .about-teams > .about-team-card:nth-child(3) {
    margin-top: 14px;
  }

  .page-about .about-sync__grid {
    grid-template-columns: 1.15fr .85fr;
    gap: 44px;
    align-items: start;
  }

  .page-about .about-node__grid {
    grid-template-columns: 5fr 6fr;
    gap: 46px;
    align-items: center;
  }

  .page-about .about-next__grid {
    grid-template-columns: 1.3fr .7fr;
    gap: 48px;
    align-items: start;
  }

  .page-about .about-teams__figure {
    margin-top: 44px;
  }
}