.page-about {
  --about-aside: 216px;
  --about-gap: clamp(24px, 4vw, 56px);
  --about-amber-line: rgba(242, 163, 58, 0.22);
}

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

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding-block: clamp(26px, 4vw, 48px) clamp(34px, 5vw, 64px);
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(118deg, rgba(14, 38, 32, 0.95) 0%, rgba(14, 38, 32, 0.55) 44%, rgba(11, 27, 43, 0) 74%);
  clip-path: polygon(0 0, 64% 0, 42% 100%, 0 100%);
  pointer-events: none;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  right: 0;
  top: 0;
  bottom: 0;
  width: min(38%, 420px);
  background-image:
    repeating-linear-gradient(0deg, var(--line) 0 1px, transparent 1px 34px),
    repeating-linear-gradient(90deg, var(--line) 0 1px, transparent 1px 34px);
  opacity: 0.5;
  pointer-events: none;
}

.page-about .about-hero__grid {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 28px;
}

.page-about .about-hero h1 {
  font-family: var(--font-head);
  font-size: clamp(30px, 5.6vw, 62px);
  line-height: 1.06;
  letter-spacing: -0.02em;
  font-weight: 800;
  margin: 14px 0 0;
  max-width: 16em;
}

.page-about .about-hero__lede {
  margin: 18px 0 0;
  max-width: 48ch;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.72;
  color: var(--text-mid);
}

.page-about .hero-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: clamp(24px, 3vw, 36px);
  border: 1px solid var(--line);
  background: var(--line);
}

.page-about .hero-stats__item {
  background: var(--night);
  padding: 14px 16px;
}

.page-about .hero-stats__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(24px, 3vw, 34px);
  line-height: 1.1;
  color: var(--amber);
  letter-spacing: -0.02em;
}

.page-about .hero-stats__label {
  display: block;
  margin-top: 6px;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--text-dim);
}

.page-about .about-hero__aside {
  padding: 18px 18px 20px;
}

.page-about .digest {
  list-style: none;
  margin: 14px 0 0;
  padding: 0;
}

.page-about .digest li {
  position: relative;
  padding-left: 14px;
  margin-bottom: 14px;
}

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

.page-about .digest li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.55em;
  width: 2px;
  height: 1.1em;
  background: var(--amber);
}

.page-about .digest__k {
  display: block;
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--amber);
}

.page-about .digest__v {
  display: block;
  margin-top: 4px;
  font-size: 13.5px;
  line-height: 1.65;
  color: var(--text-mid);
}

/* ---------- 章节骨架 ---------- */
.page-about .chapter {
  display: grid;
  gap: 20px;
  padding-block: clamp(34px, 5vw, 62px);
  border-top: 1px solid var(--line);
}

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

.page-about .chapter__aside {
  position: relative;
  border-left: 1px solid var(--line-strong);
  padding-left: 14px;
}

.page-about .chapter__num {
  display: block;
  font-size: clamp(44px, 8vw, 82px);
  line-height: 0.85;
  letter-spacing: -0.05em;
  color: var(--about-amber-line);
}

.page-about .chapter__stage {
  display: block;
  margin-top: 10px;
  font-size: 11.5px;
  letter-spacing: 0.16em;
  color: var(--amber);
}

.page-about .chapter__note {
  margin: 10px 0 0;
  font-size: 13px;
  line-height: 1.65;
  color: var(--text-dim);
  max-width: 24ch;
}

.page-about .chapter h2 {
  font-family: var(--font-head);
  font-size: clamp(22px, 3.2vw, 34px);
  line-height: 1.16;
  letter-spacing: -0.01em;
  font-weight: 800;
  margin: 0 0 16px;
}

.page-about .about-prose p {
  margin: 0 0 14px;
  font-size: clamp(15px, 1.5vw, 16.5px);
  line-height: 1.72;
  color: var(--text-mid);
}

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

.page-about .about-prose h3 {
  position: relative;
  margin: 26px 0 12px;
  padding-left: 12px;
  font-family: var(--font-head);
  font-size: 17px;
  line-height: 1.3;
  color: var(--text);
}

.page-about .about-prose h3::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.28em;
  width: 2px;
  height: 0.95em;
  background: var(--amber);
}

/* ---------- 要点清单 ---------- */
.page-about .checklist {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
}

.page-about .checklist li {
  position: relative;
  padding-left: 18px;
  font-size: 14.5px;
  line-height: 1.65;
  color: var(--text-mid);
}

.page-about .checklist li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.68em;
  width: 7px;
  height: 7px;
  border: 1px solid var(--amber);
}

/* ---------- 横向主题带 ---------- */
.page-about .band {
  background: var(--moss);
  border-block: 1px solid var(--line);
  padding-block: clamp(28px, 4vw, 52px);
}

.page-about .band--stand {
  background: var(--stand);
}

.page-about .band__grid {
  display: grid;
  gap: 22px;
  align-items: center;
}

.page-about .band__text h2 {
  font-family: var(--font-head);
  font-size: clamp(21px, 3vw, 30px);
  line-height: 1.2;
  font-weight: 800;
  margin: 10px 0 12px;
  letter-spacing: -0.01em;
}

.page-about .band__text p {
  margin: 0;
  font-size: clamp(14.5px, 1.5vw, 16px);
  line-height: 1.72;
  color: var(--text-mid);
  max-width: 44ch;
}

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

.page-about .band__figure .figure__media {
  overflow: hidden;
}

/* ---------- 四条资料线 ---------- */
.page-about .lines {
  display: grid;
  gap: 1px;
  margin-top: 22px;
  border: 1px solid var(--line);
  background: var(--line);
}

.page-about .lines__item {
  background: var(--stand);
  padding: 16px 18px 18px;
}

.page-about .lines__k {
  display: block;
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--amber);
}

.page-about .lines__t {
  font-family: var(--font-head);
  font-size: 18px;
  margin: 6px 0 8px;
  color: var(--text);
}

.page-about .lines__d {
  margin: 0;
  font-size: 14px;
  line-height: 1.68;
  color: var(--text-dim);
}

.page-about .flow {
  display: block;
  width: 100%;
  max-width: 560px;
  height: auto;
  margin: 26px 0 22px;
}

.page-about .flow__label {
  font-family: var(--font-mono);
  font-size: 12px;
  fill: var(--text-dim);
}

.page-about .flow__title {
  font-family: var(--font-head);
  font-size: 15px;
  fill: var(--amber-soft);
}

.page-about .flow__sub {
  font-family: var(--font-mono);
  font-size: 10.5px;
  fill: var(--text-dim);
}

/* ---------- 版本演进 ---------- */
.page-about .versions {
  position: relative;
  margin-top: 26px;
  padding-left: 24px;
}

.page-about .versions::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 10px;
  bottom: 10px;
  width: 1px;
  background: var(--line-strong);
}

.page-about .version {
  position: relative;
  margin-bottom: 10px;
}

.page-about .version::before {
  content: "";
  position: absolute;
  left: -24px;
  top: 17px;
  width: 9px;
  height: 9px;
  background: var(--amber);
  z-index: 1;
}

.page-about .version--key::before {
  background: var(--amber-soft);
  box-shadow: 0 0 0 3px rgba(255, 209, 138, 0.18);
}

.page-about .version .disclosure__trigger {
  width: 100%;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  gap: 3px 10px;
  align-items: baseline;
  padding: 12px 14px;
  text-align: left;
  background: var(--stand);
  border: 1px solid var(--line);
  border-radius: 0;
  color: var(--text);
  font-family: var(--font-head);
  font-size: 16px;
  line-height: 1.4;
  cursor: pointer;
  transition: border-color 0.2s ease, background 0.2s ease;
}

.page-about .version .disclosure__trigger:hover,
.page-about .version .disclosure__trigger:focus-visible {
  border-color: rgba(242, 163, 58, 0.55);
}

.page-about .version .disclosure__trigger[aria-expanded="true"] {
  border-color: var(--amber);
  background: var(--moss);
}

.page-about .version__no {
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--amber);
}

.page-about .version__title {
  font-weight: 700;
  color: var(--text);
}

.page-about .version__sum {
  grid-column: 1 / -1;
  font-family: var(--font-body);
  font-size: 13px;
  font-weight: 400;
  line-height: 1.6;
  color: var(--text-dim);
}

.page-about .version__list {
  list-style: none;
  margin: 0;
  padding: 2px 14px 12px 18px;
}

.page-about .version__list li {
  position: relative;
  padding-left: 16px;
  margin-top: 8px;
  font-size: 14.5px;
  line-height: 1.66;
  color: var(--text-mid);
}

.page-about .version__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 7px;
  height: 1px;
  background: var(--amber);
}

/* ---------- 团队 ---------- */
.page-about .crew {
  display: grid;
  gap: 1px;
  margin-top: 22px;
  border: 1px solid var(--line);
  background: var(--line);
}

.page-about .crew__item {
  background: var(--night);
  padding: 18px;
}

.page-about .crew__item:nth-child(2) {
  background: var(--moss);
}

.page-about .crew__item:nth-child(3) {
  background: var(--moss);
}

.page-about .crew__t {
  font-family: var(--font-head);
  font-size: 17px;
  margin: 0 0 8px;
  color: var(--text);
}

.page-about .crew__d {
  margin: 0;
  font-size: 14px;
  line-height: 1.68;
  color: var(--text-dim);
}

.page-about .crew__figure {
  margin: 26px 0 0;
}

.page-about .crew__figure .figure__media {
  overflow: hidden;
}

/* ---------- 变更提示与档案摘录 ---------- */
.page-about .notice {
  margin: 22px 0;
}

.page-about .dossier {
  margin: 22px 0;
  padding: 18px 18px 20px;
  color: var(--archive);
}

.page-about .dossier__head {
  margin: 0 0 12px;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: rgba(7, 17, 15, 0.68);
  border-bottom: 1px solid rgba(7, 17, 15, 0.22);
  padding-bottom: 10px;
}

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

.page-about .dossier__list li {
  position: relative;
  padding-left: 86px;
  margin-bottom: 10px;
  font-size: 14px;
  line-height: 1.62;
  color: rgba(7, 17, 15, 0.86);
}

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

.page-about .dossier__no {
  position: absolute;
  left: 0;
  top: 0.1em;
  font-size: 12px;
  color: #8a5a12;
  letter-spacing: 0.02em;
}

.page-about .dossier__note {
  margin: 14px 0 0;
  padding-top: 10px;
  border-top: 1px solid rgba(7, 17, 15, 0.18);
  font-size: 12.5px;
  line-height: 1.65;
  color: rgba(7, 17, 15, 0.66);
}

/* ---------- 收尾 ---------- */
.page-about .about-cta {
  display: grid;
  gap: 20px;
  margin-top: clamp(34px, 5vw, 60px);
  padding-block: clamp(30px, 4vw, 52px);
  border-top: 1px solid var(--line-strong);
}

.page-about .about-cta h2 {
  font-family: var(--font-head);
  font-size: clamp(21px, 3vw, 30px);
  line-height: 1.2;
  font-weight: 800;
  margin: 10px 0 12px;
  letter-spacing: -0.01em;
}

.page-about .about-cta p {
  margin: 0;
  max-width: 52ch;
  font-size: 15px;
  line-height: 1.72;
  color: var(--text-mid);
}

.page-about .about-cta__links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .about-cta__links .btn {
  text-decoration: none;
}

/* ---------- 平板与桌面 ---------- */
@media (min-width: 720px) {
  .page-about .hero-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.55fr) minmax(0, 1fr);
    gap: clamp(30px, 5vw, 72px);
    align-items: start;
  }

  .page-about .about-hero__aside {
    margin-top: 40px;
  }

  .page-about .chapter {
    grid-template-columns: var(--about-aside) minmax(0, 1fr);
    gap: var(--about-gap);
  }

  .page-about .chapter__aside {
    position: sticky;
    top: 32px;
    align-self: start;
  }

  .page-about .band__grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.1fr);
    gap: clamp(28px, 5vw, 64px);
  }

  .page-about .band__grid--flip {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 1fr);
  }

  .page-about .band__grid--flip .band__text {
    order: 2;
  }

  .page-about .band__grid--flip .band__figure {
    order: 1;
  }

  .page-about .about-cta {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: end;
    gap: clamp(24px, 4vw, 56px);
  }

  .page-about .about-cta__links {
    justify-content: flex-end;
    max-width: 320px;
  }
}

@media (min-width: 1200px) {
  .page-about .chapter {
    grid-template-columns: 240px minmax(0, 1fr);
  }
}

@media (max-width: 639px) {
  .page-about .flow__label,
  .page-about .flow__sub {
    display: none;
  }

  .page-about .flow__title {
    font-size: 13px;
  }

  .page-about .dossier__list li {
    padding-left: 0;
    padding-top: 18px;
  }

  .page-about .dossier__no {
    top: 0;
  }

  .page-about .about-hero::before {
    clip-path: polygon(0 0, 100% 0, 100% 58%, 0 84%);
    opacity: 0.7;
  }

  .page-about .about-hero::after {
    display: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .version .disclosure__trigger {
    transition: none;
  }
}