.page-about {
  background: var(--bg);
  color: var(--fg);
  overflow-x: hidden;
}

.page-about .about-crumb-wrap {
  padding-top: 22px;
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  padding: clamp(30px, 5vw, 64px) 0 clamp(28px, 4vw, 52px);
  border-bottom: var(--rule);
}

.page-about .about-hero-inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 34px;
}

.page-about .about-eyebrow {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--cyan);
}

.page-about .about-h1 {
  margin: 0 0 16px;
  font-family: var(--font-serif);
  font-weight: 900;
  font-size: clamp(30px, 6vw, 46px);
  line-height: 1.18;
  letter-spacing: -.02em;
  overflow-wrap: break-word;
}

.page-about .about-lede {
  margin: 0 0 24px;
  font-size: 17px;
  line-height: 1.7;
  color: var(--fg);
  max-width: 46ch;
}

.page-about .about-hero-aside {
  border-top: var(--rule-strong);
}

.page-about .about-stat-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.page-about .about-stat {
  padding: 18px 12px 18px 0;
  border-bottom: var(--rule);
}

.page-about .about-stat-num {
  display: block;
  font-family: var(--font-mono);
  font-size: 30px;
  font-weight: 700;
  line-height: 1;
  color: var(--cyan);
  letter-spacing: -.01em;
}

.page-about .about-stat:nth-child(2) .about-stat-num,
.page-about .about-stat:nth-child(4) .about-stat-num {
  color: var(--orange);
}

.page-about .about-stat-label {
  display: block;
  margin-top: 8px;
  font-size: 13px;
  line-height: 1.5;
  color: var(--muted);
}

@media (min-width: 900px) {
  .page-about .about-hero-inner {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: 56px;
    align-items: end;
  }
}

/* ---------- 顶部索引带 ---------- */

.page-about .about-index {
  background: var(--panel);
  border-bottom: var(--rule);
}

.page-about .about-index .index-band-inner {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  column-gap: 22px;
}

.page-about .about-index .index-item {
  display: flex;
  flex-direction: column;
  gap: 5px;
  padding: 16px 0;
  border-bottom: var(--rule);
}

.page-about .about-index .index-link {
  font-size: 15px;
  font-weight: 600;
  color: var(--fg);
  text-decoration: none;
  letter-spacing: .01em;
}

.page-about .about-index .index-link:hover,
.page-about .about-index .index-link:focus-visible {
  color: var(--cyan);
}

.page-about .about-index .index-count {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--muted);
}

@media (min-width: 720px) {
  .page-about .about-index .index-band-inner {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 1040px) {
  .page-about .about-index .index-band-inner {
    grid-template-columns: repeat(6, minmax(0, 1fr));
  }
  .page-about .about-index .index-item {
    border-bottom: 0;
    padding: 20px 0;
  }
}

/* ---------- 区块通用 ---------- */

.page-about .about-block {
  padding: clamp(44px, 7vw, 86px) 0;
  border-bottom: var(--rule);
}

.page-about .about-head {
  max-width: 700px;
  margin-bottom: clamp(24px, 4vw, 44px);
}

.page-about .about-kicker {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--cyan);
}

.page-about .about-title {
  margin: 0 0 14px;
  font-family: var(--font-serif);
  font-weight: 800;
  font-size: clamp(24px, 3.6vw, 34px);
  line-height: 1.22;
  letter-spacing: -.02em;
  overflow-wrap: break-word;
}

.page-about .about-sub {
  margin: 0;
  font-size: 16px;
  line-height: 1.75;
  color: var(--muted);
}

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

.page-about .figure-media {
  border: var(--rule);
  overflow: hidden;
  background: var(--panel-deep);
}

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

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

/* ---------- 团队分工 ---------- */

.page-about .about-team-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 32px;
}

.page-about .about-roles {
  border-top: var(--rule-strong);
}

.page-about .about-role {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 2px 16px;
  padding: 20px 0;
  border-bottom: var(--rule);
}

.page-about .about-role-idx {
  grid-row: 1 / span 2;
  display: grid;
  place-items: center;
  width: 30px;
  height: 30px;
  border: var(--rule-strong);
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--orange);
}

.page-about .about-role-title {
  grid-column: 2;
  margin: 0;
  font-family: var(--font-sans);
  font-size: 18px;
  font-weight: 600;
  line-height: 1.3;
}

.page-about .about-role-text {
  grid-column: 2;
  margin: 8px 0 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--muted);
}

@media (min-width: 900px) {
  .page-about .about-team-grid {
    grid-template-columns: minmax(0, 6fr) minmax(0, 5fr);
    gap: 52px;
    align-items: start;
  }
}

/* ---------- 数据来源 ---------- */

.page-about .about-src-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  border-top: var(--rule-strong);
}

.page-about .about-src {
  padding: 24px 0;
  border-bottom: var(--rule);
}

.page-about .about-src-no {
  display: inline-block;
  margin-bottom: 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--orange);
}

.page-about .about-src-title {
  margin: 0 0 10px;
  font-family: var(--font-serif);
  font-size: 20px;
  font-weight: 700;
  line-height: 1.35;
}

.page-about .about-src-text {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .about-note {
  margin: 26px 0 0;
  padding-left: 16px;
  border-left: 2px solid var(--cyan);
  font-size: 14px;
  line-height: 1.75;
  color: var(--fg);
  max-width: 68ch;
}

@media (min-width: 760px) {
  .page-about .about-src-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .about-src {
    padding: 26px 24px 26px 0;
    border-bottom: 0;
    border-right: var(--rule);
  }
  .page-about .about-src:last-child {
    padding-right: 0;
    border-right: 0;
  }
}

/* ---------- 三道校验 ---------- */

.page-about .about-checks-figure {
  margin-bottom: clamp(28px, 4vw, 44px);
}

.page-about .about-segmented {
  padding-top: 22px;
  border-top: var(--rule-strong);
}

.page-about .segmented-rail {
  display: block;
  height: 1px;
  margin-bottom: 20px;
  background: var(--line);
}

.page-about .about-seg-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 26px;
}

.page-about .segmented-tab {
  appearance: none;
  background: transparent;
  border: 1px solid var(--line-2);
  color: var(--muted);
  font-family: var(--font-sans);
  font-size: 14px;
  line-height: 1.2;
  padding: 11px 16px;
  cursor: pointer;
  transition: background-color .18s ease, color .18s ease, border-color .18s ease;
}

.page-about .segmented-tab:hover {
  color: var(--fg);
  border-color: var(--cyan);
}

.page-about .segmented-tab[aria-selected="true"] {
  background: var(--cyan);
  border-color: var(--cyan);
  color: var(--bg);
  font-weight: 600;
}

.page-about .about-step {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px;
}

.page-about .about-step-side {
  padding-left: 14px;
  border-left: 2px solid var(--orange);
}

.page-about .about-step-no {
  display: block;
  font-family: var(--font-mono);
  font-size: 26px;
  font-weight: 700;
  line-height: 1;
  color: var(--orange);
}

.page-about .about-step-title {
  margin: 10px 0 6px;
  font-family: var(--font-serif);
  font-size: 20px;
  font-weight: 700;
}

.page-about .about-step-meta {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--muted);
}

.page-about .about-step-text {
  margin: 0;
  font-size: 16px;
  line-height: 1.8;
  color: var(--fg);
  max-width: 66ch;
}

@media (min-width: 820px) {
  .page-about .about-step {
    grid-template-columns: minmax(0, 4fr) minmax(0, 7fr);
    gap: 44px;
    align-items: start;
  }
}

/* ---------- 版本演进 ---------- */

.page-about .about-timeline {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 12px;
  bottom: 12px;
  width: 1px;
  background: var(--line-2);
}

.page-about .about-tl-item {
  position: relative;
  padding: 0 0 30px 32px;
}

.page-about .about-tl-item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 7px;
  width: 9px;
  height: 9px;
  background: var(--bg);
  border: 1px solid var(--line-2);
  transition: background-color .18s ease, border-color .18s ease;
}

.page-about .about-tl-item:hover::before,
.page-about .about-tl-item:focus-within::before {
  background: var(--cyan);
  border-color: var(--cyan);
}

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

.page-about .about-tl-tag {
  display: inline-block;
  margin-bottom: 7px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--orange);
}

.page-about .about-tl-title {
  margin: 0 0 7px;
  font-size: 17px;
  font-weight: 600;
  line-height: 1.45;
}

.page-about .about-tl-text {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--muted);
  max-width: 64ch;
}

@media (min-width: 900px) {
  .page-about .about-timeline {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: 56px;
  }
  .page-about .about-timeline::before {
    display: none;
  }
  .page-about .about-tl-item {
    border-top: var(--rule);
    padding: 20px 0 26px 22px;
  }
  .page-about .about-tl-item::before {
    top: 26px;
    left: 0;
  }
  .page-about .about-tl-item:nth-child(-n+2) {
    border-top-color: var(--line-2);
  }
}

/* ---------- 覆盖与生态 ---------- */

.page-about .about-cov-grid {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border-top: var(--rule-strong);
}

.page-about .about-cov {
  padding: 22px 14px 22px 0;
  border-bottom: var(--rule);
}

.page-about .about-cov-num {
  display: block;
  font-family: var(--font-mono);
  font-size: 32px;
  font-weight: 700;
  line-height: 1;
  color: var(--cyan);
}

.page-about .about-cov-name {
  display: block;
  margin-top: 8px;
  font-size: 15px;
  font-weight: 600;
}

.page-about .about-cov-desc {
  display: block;
  margin-top: 6px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--muted);
}

.page-about .about-partners {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
  margin-top: 38px;
  border-top: var(--rule);
}

.page-about .about-partner {
  padding: 24px 0;
  border-bottom: var(--rule);
}

.page-about .about-partner-num {
  display: block;
  font-family: var(--font-mono);
  font-size: 26px;
  font-weight: 700;
  line-height: 1;
  color: var(--orange);
}

.page-about .about-partner-title {
  margin: 12px 0 8px;
  font-family: var(--font-serif);
  font-size: 19px;
  font-weight: 700;
}

.page-about .about-partner-text {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--muted);
  max-width: 54ch;
}

@media (min-width: 760px) {
  .page-about .about-cov-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .about-partners {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: 48px;
  }
}

/* ---------- 荣誉与准则（奶油纸插页） ---------- */

.page-about .about-paper {
  padding: clamp(26px, 5vw, 56px);
  color: var(--paper-ink);
}

.page-about .about-kicker-ink {
  color: var(--paper-ink);
  opacity: .6;
}

.page-about .about-title-ink {
  color: var(--paper-ink);
}

.page-about .about-paper-lede {
  margin: 0;
  font-size: 16px;
  line-height: 1.8;
  color: var(--paper-ink);
  max-width: 68ch;
}

.page-about .about-rules {
  list-style: none;
  margin: 34px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  border-top: 1px solid rgba(26, 20, 16, .2);
}

.page-about .about-rule {
  padding: 22px 20px 22px 0;
  border-bottom: 1px solid rgba(26, 20, 16, .2);
}

.page-about .about-rule-no {
  display: grid;
  place-items: center;
  width: 28px;
  height: 28px;
  margin-bottom: 12px;
  border: 1px solid rgba(26, 20, 16, .4);
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--paper-ink);
}

.page-about .about-rule-title {
  margin: 0 0 8px;
  font-family: var(--font-serif);
  font-size: 18px;
  font-weight: 700;
  color: var(--paper-ink);
}

.page-about .about-rule-text {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: rgba(26, 20, 16, .78);
}

@media (min-width: 820px) {
  .page-about .about-rules {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    column-gap: 32px;
  }
  .page-about .about-rule {
    padding-right: 0;
  }
}

/* ---------- 延伸路径 ---------- */

.page-about .about-path-block {
  border-bottom: 0;
}

.page-about .about-path-list {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  margin-top: 26px;
  border-top: var(--rule-strong);
}

.page-about .about-path {
  display: block;
  padding: 26px 0;
  border-bottom: var(--rule);
  text-decoration: none;
  color: inherit;
}

.page-about .about-path-title {
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-serif);
  font-size: 20px;
  font-weight: 700;
  transition: color .18s ease;
}

.page-about .about-path-desc {
  display: block;
  font-size: 15px;
  line-height: 1.75;
  color: var(--muted);
  max-width: 40ch;
}

.page-about .about-path-arrow {
  display: inline-block;
  margin-top: 14px;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--orange);
}

.page-about .about-path:hover .about-path-title,
.page-about .about-path:focus-visible .about-path-title {
  color: var(--cyan);
}

@media (min-width: 820px) {
  .page-about .about-path-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .about-path {
    padding: 30px 30px 30px 0;
    border-bottom: 0;
    border-right: var(--rule);
  }
  .page-about .about-path:last-child {
    padding-right: 0;
    border-right: 0;
  }
  .page-about .about-path + .about-path {
    padding-left: 30px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about * {
    transition: none !important;
    animation: none !important;
  }
}