.page-about {
  --about-pad: clamp(22px, 4vw, 56px);
  --about-rule: rgba(36, 26, 21, .16);
  --about-rule-dark: rgba(159, 179, 176, .2);
  --about-link-paper: #A83A10;
  background: var(--xl-night);
  color: var(--xl-white);
  padding-bottom: clamp(56px, 8vw, 112px);
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  padding-top: clamp(26px, 5vw, 56px);
}

.page-about .about-crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  margin-bottom: clamp(20px, 3vw, 34px);
}

.page-about .about-crumbs .xl-crumbs__item {
  font-family: var(--xl-font-mono);
  font-size: var(--xl-fs-12);
  letter-spacing: .08em;
  color: var(--xl-silver);
}

.page-about .about-crumbs .xl-crumbs__item + .xl-crumbs__item::before {
  content: "/ ";
  color: var(--xl-edge);
}

.page-about .about-crumbs .xl-link {
  color: var(--xl-silver);
  text-decoration: none;
}

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

.page-about .about-hero__eyebrow {
  margin: 0;
  font-family: var(--xl-font-mono);
  font-size: var(--xl-fs-13);
  letter-spacing: .2em;
  color: var(--xl-cyan);
}

.page-about .about-hero__title {
  margin: 16px 0 0;
  font-family: var(--xl-font-display);
  font-weight: 800;
  font-size: clamp(2rem, 6.2vw, var(--xl-fs-64));
  line-height: 1.08;
  letter-spacing: -.02em;
  max-width: 15em;
}

.page-about .about-hero__lede {
  margin: clamp(18px, 2.6vw, 28px) 0 0;
  font-size: clamp(1rem, 1.9vw, var(--xl-fs-20));
  line-height: 1.78;
  color: var(--xl-silver);
  max-width: 32em;
}

.page-about .about-hero__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(28px, 4vw, 46px) 0 0;
  padding: 0;
  list-style: none;
  background: var(--about-rule-dark);
  border: 1px solid var(--about-rule-dark);
  border-radius: var(--xl-radius-md);
  overflow: hidden;
}

@media (min-width: 760px) {
  .page-about .about-hero__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.page-about .about-hero__fact {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: clamp(16px, 2.4vw, 26px);
  background: var(--xl-night);
}

.page-about .about-hero__num {
  font-family: var(--xl-font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(1.4rem, 3vw, var(--xl-fs-28));
  line-height: 1.1;
  color: var(--xl-cyan);
  letter-spacing: -.01em;
}

.page-about .about-hero__lbl {
  font-size: var(--xl-fs-13);
  color: var(--xl-silver);
}

.page-about .about-hero__figure {
  position: relative;
  width: min(1240px, calc(100% - 2 * var(--xl-gutter)));
  margin: clamp(30px, 5vw, 60px) auto 0;
  border-radius: var(--xl-radius-lg);
  overflow: hidden;
  background: var(--xl-pitch);
}

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

.page-about .about-hero__figure::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(to right, rgba(56, 242, 200, .1) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(56, 242, 200, .1) 1px, transparent 1px);
  background-size: 68px 68px;
}

.page-about .about-hero__cap {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 46px clamp(18px, 3vw, 34px) clamp(16px, 2.4vw, 26px);
  font-family: var(--xl-font-mono);
  font-size: var(--xl-fs-12);
  letter-spacing: .06em;
  color: var(--xl-white);
  background: linear-gradient(to top, rgba(6, 19, 26, .92), rgba(6, 19, 26, 0));
}

/* ---------- 主体骨架 ---------- */

.page-about .about-body {
  margin-top: clamp(46px, 7vw, 92px);
}

.page-about .about-body__inner {
  display: grid;
  gap: clamp(24px, 4vw, 46px);
  align-items: start;
}

@media (min-width: 900px) {
  .page-about .about-body__inner {
    grid-template-columns: minmax(168px, 208px) minmax(0, 1fr);
  }
}

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

@media (min-width: 900px) {
  .page-about .about-rail {
    display: block;
    position: sticky;
    top: 104px;
  }
}

.page-about .about-rail__title {
  margin: 0 0 14px;
  font-family: var(--xl-font-mono);
  font-size: var(--xl-fs-12);
  letter-spacing: .2em;
  color: var(--xl-silver);
}

.page-about .about-rail__list {
  display: grid;
  gap: 2px;
  margin: 0;
  padding: 0;
  list-style: none;
  border-left: 1px solid var(--xl-edge);
}

.page-about .about-rail__link {
  display: block;
  margin-left: -1px;
  padding: 9px 0 9px 16px;
  border-left: 2px solid transparent;
  font-size: 14px;
  line-height: 1.5;
  color: var(--xl-silver);
  text-decoration: none;
  transition: color .16s ease, border-color .16s ease;
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  color: var(--xl-white);
}

.page-about .about-rail__link[aria-current="true"] {
  color: var(--xl-cyan);
  border-left-color: var(--xl-cyan);
}

/* ---------- 章节块 ---------- */

.page-about .about-chapter {
  position: relative;
  border-radius: var(--xl-radius-lg);
  padding: clamp(30px, 5vw, 62px) var(--about-pad);
  margin-bottom: clamp(18px, 2.6vw, 28px);
  overflow: hidden;
}

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

.page-about .about-chapter--paper {
  background: var(--xl-cream);
  color: var(--xl-ink);
}

.page-about .about-chapter--pitch {
  background: linear-gradient(150deg, var(--xl-pitch), #05170f 92%);
  border: 1px solid var(--xl-edge);
  color: var(--xl-white);
}

.page-about .about-chapter--bare {
  background: transparent;
  padding-inline: 0;
  border-radius: 0;
}

.page-about .about-chapter__num {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-family: var(--xl-font-mono);
  font-size: var(--xl-fs-13);
  letter-spacing: .2em;
}

.page-about .about-chapter__num::after {
  content: "";
  width: clamp(40px, 9vw, 96px);
  height: 1px;
  background: currentColor;
  opacity: .42;
}

.page-about .about-chapter--paper .about-chapter__num {
  color: var(--about-link-paper);
}

.page-about .about-chapter--pitch .about-chapter__num {
  color: var(--xl-cyan);
}

.page-about .about-chapter__title {
  margin: 18px 0 0;
  font-family: var(--xl-font-editorial);
  font-weight: 600;
  font-size: clamp(1.45rem, 3.4vw, 2.5rem);
  line-height: 1.24;
  letter-spacing: .01em;
}

.page-about .about-chapter__lede {
  margin: 16px 0 0;
  font-size: clamp(1rem, 1.7vw, var(--xl-fs-20));
  line-height: 1.78;
  max-width: 30em;
  opacity: .94;
}

.page-about .about-prose {
  margin-top: clamp(22px, 3vw, 34px);
  max-width: 42rem;
}

.page-about .about-prose p {
  margin: 0 0 1.15em;
  font-size: var(--xl-fs-16);
  line-height: 1.88;
}

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

/* ---------- 链接色彩 ---------- */

.page-about .about-chapter--paper .about-prose a,
.page-about .about-chapter--paper .about-haikou__text a,
.page-about .about-chapter--bare a {
  color: var(--about-link-paper);
  text-decoration-color: rgba(168, 58, 16, .45);
}

.page-about .about-chapter--paper .about-prose a:hover,
.page-about .about-chapter--paper .about-haikou__text a:hover,
.page-about .about-chapter--bare a:hover {
  color: var(--xl-orange);
}

.page-about .about-chapter--pitch .about-prose a {
  color: var(--xl-cyan);
  text-decoration-color: rgba(56, 242, 200, .4);
}

/* ---------- 版本长卷 ---------- */

.page-about .about-versions {
  display: flex;
  gap: 12px;
  overflow-x: auto;
  scroll-snap-type: x proximity;
  -webkit-overflow-scrolling: touch;
  margin: clamp(26px, 4vw, 40px) calc(-1 * var(--about-pad)) 0;
  padding: 4px var(--about-pad) 20px;
}

.page-about .about-versions::-webkit-scrollbar {
  height: 4px;
}

.page-about .about-versions::-webkit-scrollbar-thumb {
  background: var(--xl-edge);
  border-radius: var(--xl-pill);
}

.page-about .about-ver {
  flex: 0 0 min(274px, 76vw);
  scroll-snap-align: start;
  border: 1px solid var(--xl-edge);
  border-radius: var(--xl-radius-md);
  background: rgba(56, 242, 200, .05);
  overflow: hidden;
  transition: background .18s ease, border-color .18s ease;
}

.page-about .about-ver[open] {
  background: rgba(56, 242, 200, .12);
  border-color: rgba(56, 242, 200, .46);
}

.page-about .about-ver__pill {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 18px 20px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-ver__pill::marker {
  content: "";
}

@media (min-width: 640px) {
  .page-about .about-ver__pill {
    flex-direction: row;
    align-items: baseline;
    gap: 12px;
  }
}

.page-about .about-ver__pill:focus-visible {
  outline: 2px solid var(--xl-cyan);
  outline-offset: -2px;
}

.page-about .about-ver__no {
  font-family: var(--xl-font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--xl-fs-20);
  letter-spacing: .04em;
  color: var(--xl-cyan);
}

.page-about .about-ver__name {
  font-size: 15px;
  font-weight: 600;
  line-height: 1.5;
  color: var(--xl-white);
}

.page-about .about-ver__body {
  margin: 0;
  padding: 0 20px 20px;
  font-size: 14.5px;
  line-height: 1.82;
  color: var(--xl-silver);
}

/* ---------- 用户画像 ---------- */

.page-about .about-viewers {
  margin: clamp(24px, 4vw, 38px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-viewer {
  display: grid;
  gap: 10px;
  padding: clamp(20px, 3vw, 30px) 0;
  border-top: 1px solid var(--about-rule);
}

.page-about .about-viewer:first-child {
  border-top: 0;
  padding-top: 0;
}

@media (min-width: 700px) {
  .page-about .about-viewer {
    grid-template-columns: 78px minmax(0, 1fr);
    gap: 26px;
    align-items: start;
  }
}

.page-about .about-viewer__no {
  font-family: var(--xl-font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--xl-fs-28);
  line-height: 1;
  color: var(--xl-orange);
}

.page-about .about-viewer__title {
  margin: 0 0 10px;
  font-family: var(--xl-font-editorial);
  font-weight: 600;
  font-size: clamp(1.08rem, 2vw, var(--xl-fs-20));
  line-height: 1.5;
}

.page-about .about-viewer__txt {
  margin: 0;
  font-size: var(--xl-fs-16);
  line-height: 1.86;
  max-width: 40rem;
}

/* ---------- 团队分工 ---------- */

.page-about .about-tree {
  margin-top: clamp(24px, 4vw, 38px);
  border: 1px solid var(--xl-edge);
  border-radius: var(--xl-radius-md);
  background: rgba(56, 242, 200, .04);
  overflow: hidden;
}

.page-about .about-tree__sum {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 18px 22px;
  cursor: pointer;
  list-style: none;
  font-family: var(--xl-font-mono);
  font-size: var(--xl-fs-13);
  letter-spacing: .1em;
  color: var(--xl-cyan);
}

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

.page-about .about-tree__sum::marker {
  content: "";
}

.page-about .about-tree__sum:focus-visible {
  outline: 2px solid var(--xl-cyan);
  outline-offset: -2px;
}

.page-about .about-tree__dot {
  flex: 0 0 auto;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--xl-cyan);
  box-shadow: 0 0 0 4px rgba(56, 242, 200, .16);
}

.page-about .about-tree__hint {
  margin-left: auto;
  font-size: var(--xl-fs-12);
  letter-spacing: .06em;
  color: var(--xl-silver);
}

.page-about .about-tree__branches {
  display: grid;
  gap: 18px;
  margin: 0;
  padding: 20px 22px 24px;
  list-style: none;
  border-top: 1px solid var(--xl-edge);
}

@media (min-width: 780px) {
  .page-about .about-tree__branches {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 26px;
  }
}

.page-about .about-tree__branch {
  display: grid;
  gap: 8px;
}

.page-about .about-tree__branch::before {
  content: "";
  width: 24px;
  height: 2px;
  border-radius: var(--xl-pill);
  background: var(--xl-orange);
}

.page-about .about-tree__name {
  margin: 0;
  font-size: var(--xl-fs-16);
  font-weight: 700;
  color: var(--xl-white);
}

.page-about .about-tree__txt {
  margin: 0;
  font-size: 15px;
  line-height: 1.82;
  color: var(--xl-silver);
}

/* ---------- 海南联络 ---------- */

.page-about .about-haikou {
  display: grid;
  gap: clamp(22px, 3vw, 36px);
  margin-top: clamp(20px, 3vw, 30px);
  align-items: start;
}

@media (min-width: 780px) {
  .page-about .about-haikou {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
  }
}

.page-about .about-haikou__text .about-prose {
  margin-top: 0;
}

.page-about .about-haikou__figure {
  margin: 0;
  border-radius: var(--xl-radius-md);
  overflow: hidden;
  background: var(--xl-deep);
}

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

.page-about .about-haikou__cap {
  padding: 10px 2px 0;
  font-family: var(--xl-font-mono);
  font-size: var(--xl-fs-12);
  letter-spacing: .05em;
  color: rgba(36, 26, 21, .62);
}

/* ---------- 收尾 ---------- */

.page-about .about-next {
  display: grid;
  gap: clamp(24px, 4vw, 40px);
  margin-top: clamp(22px, 3vw, 34px);
  align-items: center;
}

@media (min-width: 820px) {
  .page-about .about-next {
    grid-template-columns: minmax(0, 1.5fr) auto;
  }
}

.page-about .about-next .about-prose {
  margin-top: 0;
}

.page-about .about-next__cta {
  display: flex;
  justify-content: flex-start;
}

@media (min-width: 820px) {
  .page-about .about-next__cta {
    justify-content: flex-end;
  }
}

.page-about .about-next__cta .xl-btn {
  white-space: nowrap;
}

/* ---------- 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;
    scroll-behavior: auto !important;
  }
}