.page-about {
  --about-rule: 1px solid rgba(169, 232, 224, 0.18);
  --about-stack: 9px 9px 0 rgba(7, 26, 43, 0.45);
  --about-rail-w: 188px;

  background: var(--abyss);
  color: var(--paper);
  font-family: var(--font-sans);
  padding-bottom: 64px;
}

.page-about .about-topbar {
  width: min(100% - 40px, var(--wrap));
  margin-inline: auto;
  padding-top: 22px;
}

/* ---------- 刊头 ---------- */

.page-about .about-masthead {
  width: min(100% - 40px, var(--wrap));
  margin-inline: auto;
  padding: 48px 0 56px;
  text-align: center;
  border-bottom: var(--about-rule);
}

.page-about .about-h1 {
  margin: 16px auto 22px;
  max-width: 17ch;
  font-size: clamp(32px, 8.4vw, 66px);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: 0.015em;
  color: var(--paper);
}

.page-about .about-lede {
  max-width: 63ch;
  margin: 0 auto;
  font-size: 16px;
  line-height: 1.9;
  color: rgba(245, 241, 232, 0.8);
}

.page-about .about-facts {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px 34px;
  margin: 32px 0 0;
  padding: 0;
  list-style: none;
  font-size: 13px;
  letter-spacing: 0.02em;
  color: var(--shallow);
}

.page-about .about-facts li {
  display: flex;
  align-items: baseline;
  gap: 8px;
}

.page-about .about-facts .mono {
  font-size: 21px;
  font-weight: 600;
  color: var(--coral);
}

/* ---------- 页壳：左侧索引 + 右侧内容 ---------- */

.page-about .about-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 34px;
  width: min(100% - 40px, var(--wrap));
  margin-inline: auto;
  padding-top: 44px;
}

.page-about .about-rail {
  border-top: 2px solid var(--cyan);
  padding-top: 16px;
}

.page-about .about-rail .rail-title {
  margin: 0 0 14px;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--cyan);
}

.page-about .about-rail .rail-link {
  display: block;
  padding: 8px 0 8px 13px;
  border-left: 1px solid rgba(169, 232, 224, 0.22);
  color: rgba(245, 241, 232, 0.7);
  font-size: 14px;
  line-height: 1.5;
  text-decoration: none;
  transition: color 0.2s ease, border-color 0.2s ease, padding-left 0.2s ease;
}

.page-about .about-rail .rail-link:hover,
.page-about .about-rail .rail-link:focus-visible {
  color: var(--cyan);
  border-left-color: var(--cyan);
  padding-left: 17px;
}

.page-about .about-rail-note {
  margin: 26px 0 0;
  padding: 13px 14px;
  background: rgba(18, 59, 92, 0.72);
  border: 1px solid rgba(169, 232, 224, 0.18);
  font-size: 12.5px;
  line-height: 1.75;
  color: var(--shallow);
}

/* ---------- 章节通用 ---------- */

.page-about .about-section {
  padding: 8px 0 46px;
  border-bottom: var(--about-rule);
}

.page-about .about-section:last-of-type {
  border-bottom: 0;
}

.page-about .about-section .eyebrow {
  color: var(--cyan);
  font-size: 12px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  margin: 0 0 12px;
}

.page-about .about-section .section-title {
  margin: 0 0 26px;
  max-width: 24ch;
  font-size: clamp(23px, 5vw, 36px);
  font-weight: 800;
  line-height: 1.28;
  letter-spacing: 0.01em;
  color: var(--paper);
}

.page-about .about-prose p {
  margin: 0 0 18px;
  font-size: 15.5px;
  line-height: 1.9;
  color: rgba(245, 241, 232, 0.82);
}

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

.page-about .about-prose a,
.page-about .about-inline-cta a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(23, 224, 200, 0.42);
  padding-bottom: 1px;
  transition: border-color 0.2s ease, color 0.2s ease;
}

.page-about .about-prose a:hover,
.page-about .about-inline-cta a:hover {
  color: var(--coral);
  border-bottom-color: var(--coral);
}

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

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

/* ---------- 品牌定位 ---------- */

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

.page-about .duty-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
  margin: 34px 0 0;
  padding: 0;
  list-style: none;
  border-top: var(--about-rule);
}

.page-about .duty-item {
  position: relative;
  padding: 18px 0 18px 22px;
  border-bottom: var(--about-rule);
}

.page-about .duty-dot {
  position: absolute;
  left: 0;
  top: 25px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--cyan);
}

.page-about .duty-dot--coral {
  background: var(--coral);
}

.page-about .duty-dot--moss {
  background: var(--moss);
}

.page-about .duty-title {
  margin: 0 0 6px;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.03em;
  color: var(--paper);
}

.page-about .duty-text {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: rgba(245, 241, 232, 0.68);
}

/* ---------- 发展历程 ---------- */

.page-about .about-timeline-section {
  background: var(--paper);
  color: var(--ink);
  padding: 32px 22px 36px;
  box-shadow: var(--about-stack);
  border-bottom: 0;
}

.page-about .about-timeline-section .eyebrow {
  color: var(--clay);
}

.page-about .about-timeline-section .section-title {
  color: var(--abyss);
}

.page-about .about-timeline {
  margin: 0 0 30px;
  padding: 0 0 0 6px;
  list-style: none;
}

.page-about .tl-node {
  position: relative;
  padding: 0 0 26px 30px;
  border-left: 2px solid rgba(11, 42, 69, 0.14);
}

.page-about .tl-node:last-child {
  padding-bottom: 4px;
  border-left-color: transparent;
}

.page-about .tl-node::before {
  content: "";
  position: absolute;
  left: -9px;
  top: 4px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--paper);
  border: 3px solid var(--abyss);
}

.page-about .tl-node:first-child::before {
  border-color: var(--coral);
  background: var(--coral);
}

.page-about .tl-index {
  margin: 0 0 2px;
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--clay);
}

.page-about .tl-title {
  margin: 0 0 8px;
  font-size: 18px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--abyss);
}

.page-about .tl-text {
  margin: 0;
  max-width: 60ch;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--stone);
}

.page-about .about-fig--timeline {
  border: 1px solid rgba(11, 42, 69, 0.14);
}

/* ---------- 团队与能力 ---------- */

.page-about .about-team-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
}

.page-about .team-card {
  padding: 22px 20px 24px;
  background: var(--deep);
  border: 1px solid rgba(169, 232, 224, 0.16);
  border-top: 3px solid var(--cyan);
}

.page-about .team-card--accent {
  border-top-color: var(--coral);
  background: linear-gradient(160deg, rgba(18, 59, 92, 0.95), rgba(11, 42, 69, 0.95));
}

.page-about .team-num {
  margin: 0 0 4px;
  font-size: 34px;
  font-weight: 700;
  line-height: 1;
  color: var(--cyan);
}

.page-about .team-card--accent .team-num {
  color: var(--coral);
}

.page-about .team-name {
  margin: 0 0 10px;
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--paper);
}

.page-about .team-text {
  margin: 0;
  font-size: 14px;
  line-height: 1.82;
  color: rgba(245, 241, 232, 0.72);
}

.page-about .about-fig--team {
  margin-top: 26px;
}

/* ---------- 服务积累 ---------- */

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

.page-about .cred-card {
  padding: 20px 18px 22px;
  background: rgba(18, 59, 92, 0.55);
  border: 1px solid rgba(169, 232, 224, 0.16);
}

.page-about .cred-stamp {
  display: inline-block;
  margin: 0 0 12px;
  padding: 4px 9px;
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--abyss);
  background: var(--shallow);
}

.page-about .cred-title {
  margin: 0 0 8px;
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--paper);
}

.page-about .cred-text {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.82;
  color: rgba(245, 241, 232, 0.7);
}

/* ---------- 合作生态 ---------- */

.page-about .partner-list {
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: var(--about-rule);
}

.page-about .partner-item {
  padding: 20px 0 20px 18px;
  border-bottom: var(--about-rule);
  border-left: 3px solid rgba(23, 224, 200, 0.35);
}

.page-about .partner-item:hover {
  border-left-color: var(--coral);
}

.page-about .partner-name {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--cyan);
}

.page-about .partner-text {
  margin: 0;
  max-width: 62ch;
  font-size: 14.5px;
  line-height: 1.85;
  color: rgba(245, 241, 232, 0.76);
}

.page-about .about-inline-cta {
  margin: 24px 0 0;
  font-size: 14.5px;
  line-height: 1.85;
  color: rgba(245, 241, 232, 0.76);
}

/* ---------- 更新节奏 ---------- */

.page-about .cadence-list {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .cadence-item {
  padding: 20px 18px 22px;
  background: rgba(18, 59, 92, 0.42);
  border-left: 3px solid var(--coral);
}

.page-about .cadence-freq {
  margin: 0 0 8px;
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--coral);
}

.page-about .cadence-name {
  margin: 0 0 8px;
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--paper);
}

.page-about .cadence-text {
  margin: 0;
  font-size: 14px;
  line-height: 1.82;
  color: rgba(245, 241, 232, 0.72);
}

/* ---------- 结尾通道 ---------- */

.page-about .about-cta {
  margin-top: 12px;
  padding: 30px 22px 32px;
  background: linear-gradient(135deg, rgba(23, 224, 200, 0.1), rgba(255, 107, 74, 0.08));
  border: 1px solid rgba(23, 224, 200, 0.28);
}

.page-about .about-cta-title {
  margin: 0 0 12px;
  font-size: clamp(21px, 4.4vw, 28px);
  font-weight: 800;
  line-height: 1.3;
  color: var(--paper);
}

.page-about .about-cta-text {
  margin: 0 0 22px;
  max-width: 58ch;
  font-size: 14.5px;
  line-height: 1.85;
  color: rgba(245, 241, 232, 0.78);
}

.page-about .about-cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 0;
}

/* ---------- 断点 ---------- */

@media (min-width: 640px) {
  .page-about .duty-row {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    border-bottom: var(--about-rule);
  }

  .page-about .duty-item {
    padding: 20px 18px 22px 20px;
    border-bottom: 0;
    border-right: var(--about-rule);
  }

  .page-about .duty-item:last-child {
    border-right: 0;
  }

  .page-about .duty-dot {
    top: 26px;
  }

  .page-about .cred-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px;
  }

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

  .page-about .about-timeline-section {
    padding: 40px 34px 44px;
  }
}

@media (min-width: 860px) {
  .page-about .about-team-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-split {
    grid-template-columns: minmax(0, 1.02fr) minmax(0, 0.98fr);
    gap: 42px;
  }
}

@media (min-width: 980px) {
  .page-about .about-shell {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: 58px;
    padding-top: 52px;
  }

  .page-about .about-rail {
    position: sticky;
    top: 96px;
  }

  .page-about .about-masthead {
    padding: 64px 0 68px;
  }

  .page-about .about-section {
    padding-bottom: 58px;
  }

  .page-about .about-timeline-section {
    padding: 46px 44px 50px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-rail .rail-link,
  .page-about .about-prose a,
  .page-about .about-inline-cta a {
    transition: none;
  }
}