.page-about {
  --about-line: var(--edge);
  display: block;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  background:
    radial-gradient(760px 380px at 84% -8%, rgba(57, 255, 136, 0.14), transparent 68%),
    radial-gradient(520px 320px at 8% 110%, rgba(255, 138, 61, 0.10), transparent 70%),
    linear-gradient(180deg, var(--night) 0%, var(--stand) 100%);
  border-bottom: 3px solid var(--about-line);
  overflow: hidden;
}

.page-about .about-hero .breadcrumb {
  padding-top: clamp(18px, 3.5vw, 34px);
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(28px, 5vw, 56px);
  padding: clamp(28px, 5vw, 56px) 0 clamp(40px, 6vw, 76px);
}

.page-about .about-hero__label {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.2em;
  color: var(--amber);
  border: 2px solid var(--about-line);
  background: rgba(16, 36, 77, 0.55);
  padding: 7px 13px;
  margin-bottom: 22px;
}

.page-about .about-hero__title {
  font-family: var(--font-display);
  font-weight: 200;
  font-size: clamp(2.15rem, 7.2vw, 5.2rem);
  line-height: 1.02;
  letter-spacing: -0.035em;
  color: var(--ice);
  margin: 0 0 24px;
  max-width: 16ch;
}

.page-about .about-hero__title em {
  font-style: normal;
  color: var(--neon);
}

.page-about .about-hero__text {
  font-family: var(--font-body);
  font-size: clamp(0.98rem, 1.5vw, 1.08rem);
  line-height: 1.85;
  color: var(--mist);
  margin: 0 0 30px;
  max-width: 54ch;
}

.page-about .about-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 2px;
  background: var(--about-line);
  border: 2px solid var(--about-line);
}

.page-about .about-facts__cell {
  background: var(--night);
  padding: 15px 14px;
  min-width: 0;
}

.page-about .about-facts__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(0.95rem, 1.9vw, 1.25rem);
  color: var(--neon);
  line-height: 1.2;
  overflow-wrap: anywhere;
}

.page-about .about-facts__cap {
  display: block;
  margin-top: 6px;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.16em;
  color: var(--mist);
}

/* ---------- 视觉框 ---------- */
.page-about .about-visual {
  position: relative;
  margin: 0;
  border: 3px solid var(--line);
  background: var(--panel);
  box-shadow: var(--shadow-hard);
}

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

.page-about .about-visual::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: repeating-linear-gradient(
    180deg,
    rgba(230, 241, 255, 0.05) 0 1px,
    transparent 1px 5px
  );
}

.page-about .about-visual figcaption {
  position: relative;
  z-index: 1;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: var(--mist);
  background: var(--night);
  border-top: 2px solid var(--line);
  padding: 11px 14px;
  line-height: 1.6;
}

.page-about .about-visual--inset {
  margin: 30px 0 0;
}

.page-about .about-visual--wide {
  margin: 34px 0 0;
}

/* ---------- 章节索引条 ---------- */
.page-about .about-toc {
  background: var(--stand);
  border-bottom: 3px solid var(--about-line);
}

.page-about .about-toc__inner {
  display: flex;
  align-items: center;
  gap: 8px;
  overflow-x: auto;
  padding: 14px 0;
  scrollbar-width: none;
  -webkit-overflow-scrolling: touch;
}

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

.page-about .about-toc__link {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 8px 14px;
  border: 2px solid var(--about-line);
  color: var(--mist);
  font-family: var(--font-mono);
  font-size: 0.76rem;
  letter-spacing: 0.08em;
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.18s ease, background 0.18s ease, border-color 0.18s ease, transform 0.18s ease;
}

.page-about .about-toc__no {
  color: var(--amber);
  transition: color 0.18s ease;
}

.page-about .about-toc__link:hover,
.page-about .about-toc__link:focus-visible {
  color: var(--night);
  background: var(--neon);
  border-color: var(--neon);
  transform: translateY(-2px);
  outline: none;
}

.page-about .about-toc__link:hover .about-toc__no,
.page-about .about-toc__link:focus-visible .about-toc__no {
  color: var(--night);
}

/* ---------- 章节骨架 ---------- */
.page-about .about-chapter {
  background: var(--night);
  border-bottom: 2px solid var(--about-line);
}

.page-about .about-chapter--last {
  border-bottom: 0;
  background:
    radial-gradient(680px 320px at 90% 0%, rgba(57, 255, 136, 0.09), transparent 70%),
    var(--night);
}

.page-about .about-chapter__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 26px;
  padding: clamp(44px, 7vw, 84px) 0 clamp(48px, 7vw, 90px);
}

.page-about .about-chapter__no {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.22em;
  color: var(--amber);
  margin-bottom: 16px;
}

.page-about .about-chapter__title {
  font-family: var(--font-display);
  font-weight: 200;
  font-size: clamp(1.75rem, 4.2vw, 3rem);
  line-height: 1.06;
  letter-spacing: -0.03em;
  color: var(--ice);
  margin: 0;
}

.page-about .about-chapter__title em {
  font-style: normal;
  color: var(--neon);
}

.page-about .about-chapter__body {
  font-family: var(--font-body);
  color: var(--mist);
  font-size: 1rem;
  line-height: 1.8;
  min-width: 0;
}

.page-about .about-chapter__body > p {
  margin: 0 0 1.15em;
  max-width: 60ch;
}

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

.page-about .about-chapter__body a {
  color: var(--neon);
  text-decoration: none;
  border-bottom: 2px solid rgba(57, 255, 136, 0.35);
  transition: border-color 0.18s ease, color 0.18s ease;
}

.page-about .about-chapter__body a:hover,
.page-about .about-chapter__body a:focus-visible {
  border-color: var(--neon);
}

/* ---------- 服务对象 ---------- */
.page-about .aud-list {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin-top: 6px;
}

.page-about .aud-card {
  border: 2px solid var(--line);
  background: var(--panel);
  padding: 20px 18px;
  box-shadow: 6px 6px 0 0 rgba(3, 7, 16, 0.9);
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}

.page-about .aud-card:hover {
  transform: translate(-2px, -2px);
  box-shadow: 3px 3px 0 0 rgba(3, 7, 16, 0.9);
  border-color: var(--neon);
}

.page-about .aud-card__tag {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.16em;
  color: var(--amber);
  margin-bottom: 10px;
}

.page-about .aud-card h3 {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.12rem;
  letter-spacing: -0.01em;
  color: var(--ice);
  margin: 0 0 8px;
}

.page-about .aud-card p {
  margin: 0;
  font-size: 0.94rem;
  line-height: 1.75;
  color: var(--mist);
}

/* ---------- 数据原则 ---------- */
.page-about .rule-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
  margin-top: 8px;
  border: 2px solid var(--line);
}

.page-about .rule-card {
  position: relative;
  background: var(--stand);
  border-bottom: 2px solid var(--line);
  padding: 22px 20px;
  transition: background 0.2s ease, box-shadow 0.2s ease;
}

.page-about .rule-card:last-child {
  border-bottom: 0;
}

.page-about .rule-card:hover {
  background: var(--panel);
  box-shadow: inset 0 0 0 2px var(--neon);
}

.page-about .rule-card__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.18em;
  color: var(--neon);
  margin-bottom: 10px;
}

.page-about .rule-card h3 {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.06rem;
  letter-spacing: -0.01em;
  color: var(--ice);
  margin: 0 0 8px;
}

.page-about .rule-card p {
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.75;
  color: var(--mist);
}

/* ---------- 团队协作 ---------- */
.page-about .team-list {
  list-style: none;
  margin: 0 0 1.4em;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .team-list li {
  border-left: 3px solid var(--line);
  padding: 2px 0 2px 16px;
  font-size: 0.96rem;
  line-height: 1.78;
  transition: border-color 0.2s ease;
}

.page-about .team-list li:hover {
  border-color: var(--neon);
}

.page-about .team-role {
  display: block;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.02rem;
  color: var(--ice);
  margin-bottom: 5px;
  letter-spacing: -0.005em;
}

/* ---------- 时间轴 ---------- */
.page-about .tl {
  list-style: none;
  margin: 8px 0 0;
  padding: 0;
}

.page-about .tl__item {
  position: relative;
  padding: 0 0 30px 32px;
  border-left: 2px solid var(--line);
}

.page-about .tl__item:last-child {
  border-left-color: transparent;
  padding-bottom: 0;
}

.page-about .tl__item::before {
  content: "";
  position: absolute;
  left: -9px;
  top: 4px;
  width: 16px;
  height: 16px;
  background: var(--ember);
  border: 2px solid var(--amber);
  transition: background 0.22s ease, border-color 0.22s ease, transform 0.22s ease;
}

.page-about .tl__item:hover::before {
  background: var(--neon);
  border-color: var(--neon);
  transform: rotate(45deg);
}

.page-about .tl__stage {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.2em;
  color: var(--amber);
}

.page-about .tl__title {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.14rem;
  letter-spacing: -0.01em;
  color: var(--ice);
  margin: 7px 0 7px;
}

.page-about .tl__item:hover .tl__title {
  color: var(--neon);
}

.page-about .tl__text {
  margin: 0;
  font-size: 0.94rem;
  line-height: 1.75;
  color: var(--mist);
  max-width: 52ch;
}

/* ---------- 下一步 ---------- */
.page-about .next-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  margin: 6px 0 26px;
}

.page-about .next-card {
  display: block;
  border: 3px solid var(--line);
  background: var(--stand);
  padding: 22px 20px 20px;
  text-decoration: none;
  color: inherit;
  box-shadow: 8px 8px 0 0 rgba(3, 7, 16, 0.92);
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease, background 0.2s ease;
}

.page-about .next-card:hover,
.page-about .next-card:focus-visible {
  transform: translate(-3px, -3px);
  box-shadow: 4px 4px 0 0 rgba(3, 7, 16, 0.92);
  border-color: var(--neon);
  background: var(--panel);
  outline: none;
}

.page-about .next-card__no {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.22em;
  color: var(--amber);
  margin-bottom: 12px;
}

.page-about .next-card h3 {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.2rem;
  letter-spacing: -0.015em;
  color: var(--ice);
  margin: 0 0 9px;
}

.page-about .next-card p {
  margin: 0 0 18px;
  font-size: 0.93rem;
  line-height: 1.72;
  color: var(--mist);
}

.page-about .next-card__cta {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  letter-spacing: 0.14em;
  color: var(--neon);
  border-bottom: 2px solid rgba(57, 255, 136, 0.35);
  padding-bottom: 3px;
  transition: border-color 0.2s ease;
}

.page-about .next-card:hover .next-card__cta,
.page-about .next-card:focus-visible .next-card__cta {
  border-color: var(--neon);
}

.page-about .side-note {
  border-left: 3px solid var(--amber);
  background: rgba(58, 29, 15, 0.5);
  padding: 14px 16px;
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.75;
  color: var(--mist);
}

.page-about .side-note a {
  color: var(--neon);
}

/* ---------- 响应式 ---------- */
@media (min-width: 620px) {
  .page-about .aud-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

@media (min-width: 760px) {
  .page-about .next-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

  .page-about .rule-card {
    border-bottom: 2px solid var(--line);
    border-right: 2px solid var(--line);
  }

  .page-about .rule-card:nth-child(2n) {
    border-right: 0;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.04fr) minmax(0, 0.96fr);
    align-items: center;
  }
}

@media (min-width: 940px) {
  .page-about .about-chapter__grid {
    grid-template-columns: minmax(210px, 0.82fr) minmax(0, 1.18fr);
    gap: clamp(36px, 6vw, 92px);
  }

  .page-about .about-chapter__aside {
    position: sticky;
    top: calc(var(--header-h) + 30px);
    align-self: start;
  }

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

  .page-about .rule-card {
    border-right: 2px solid var(--line);
  }

  .page-about .rule-card:nth-child(2n) {
    border-right: 2px solid var(--line);
  }

  .page-about .rule-card:nth-child(3n) {
    border-right: 0;
  }

  .page-about .rule-card:nth-last-child(-n + 3) {
    border-bottom: 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-toc__link,
  .page-about .aud-card,
  .page-about .rule-card,
  .page-about .next-card,
  .page-about .tl__item::before,
  .page-about .team-list li {
    transition: none;
  }

  .page-about .about-toc__link:hover,
  .page-about .aud-card:hover,
  .page-about .next-card:hover,
  .page-about .next-card:focus-visible {
    transform: none;
  }

  .page-about .tl__item:hover::before {
    transform: none;
  }
}