.page-about {
  --about-rule: rgba(174, 184, 178, 0.22);
  --about-rule-soft: rgba(174, 184, 178, 0.11);
  --about-body-text: rgba(242, 237, 226, 0.80);
  --about-ink-text: rgba(6, 26, 20, 0.78);
  --about-ink-rule: rgba(6, 26, 20, 0.16);
  background:
    radial-gradient(115% 55% at 84% -8%, rgba(111, 242, 210, 0.10), transparent 62%),
    var(--ink);
  color: var(--paper);
  overflow-x: clip;
}

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

.page-about .section {
  padding-block: clamp(48px, 6.4vw, 96px);
}

.page-about .section-index {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--cyan);
  display: inline-block;
  font-variant-numeric: tabular-nums;
}

.page-about .eyebrow {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--stone);
}

/* 面包屑 */
.page-about .breadcrumb {
  padding-block: clamp(16px, 2.4vw, 28px);
}

.page-about .breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--stone);
}

.page-about .breadcrumb__list li + li::before {
  content: "/";
  margin-right: 8px;
  color: var(--moss);
}

.page-about .breadcrumb__list a {
  color: var(--stone);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--dur-1) var(--ease), border-color var(--dur-1) var(--ease);
}

.page-about .breadcrumb__list a:hover,
.page-about .breadcrumb__list a:focus-visible {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

.page-about .breadcrumb__list a:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}

/* 首屏 */
.page-about .about-masthead {
  position: relative;
  padding-bottom: clamp(32px, 5vw, 64px);
}

.page-about .about-masthead__grid {
  display: grid;
  gap: clamp(20px, 3vw, 34px);
  grid-template-columns: minmax(0, 1fr);
}

.page-about .about-masthead__aside {
  display: flex;
  align-items: baseline;
  gap: 12px;
}

.page-about .about-masthead__body h1 {
  margin: 0 0 clamp(14px, 2vw, 22px);
  font-family: var(--font-narrow);
  font-weight: 800;
  font-size: clamp(32px, 7vw, 64px);
  line-height: 1.08;
  letter-spacing: -0.012em;
  color: var(--white);
  max-width: 20ch;
}

.page-about .about-lead {
  margin: 0 0 clamp(22px, 3vw, 34px);
  max-width: 58ch;
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.9;
  color: var(--about-body-text);
}

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

.page-about .about-figures > div {
  background: var(--ink);
  padding: clamp(13px, 1.8vw, 20px);
}

.page-about .about-figures dt {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--stone);
}

.page-about .about-figures dd {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(22px, 2.8vw, 30px);
  line-height: 1.1;
  color: var(--white);
  font-variant-numeric: tabular-nums;
}

.page-about .about-figures dd small {
  display: block;
  margin-top: 6px;
  font-family: var(--font-sans);
  font-size: 11px;
  letter-spacing: 0.04em;
  color: var(--cyan);
}

.page-about .about-masthead__media {
  margin: 0;
  position: relative;
  border: 1px solid var(--about-rule-soft);
  overflow: hidden;
}

.page-about .about-masthead__media::after {
  content: "";
  position: absolute;
  inset: auto 0 0 0;
  height: 45%;
  background: linear-gradient(to top, rgba(6, 26, 20, 0.85), transparent);
  pointer-events: none;
}

.page-about .about-masthead__media img {
  width: 100%;
  object-fit: cover;
}

/* 编号章节通用 */
.page-about .about-chapter {
  border-top: 1px solid var(--about-rule-soft);
}

.page-about .about-chapter__grid {
  display: grid;
  gap: clamp(16px, 2.6vw, 34px);
  grid-template-columns: minmax(0, 1fr);
}

.page-about .about-chapter__aside {
  display: flex;
  align-items: baseline;
  gap: 10px;
}

.page-about .about-chapter__note {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--clay);
}

.page-about .about-chapter__body h2,
.page-about .about-assure__body h2,
.page-about .about-timeline__head h2 {
  margin: 0 0 clamp(14px, 2vw, 20px);
  font-family: var(--font-narrow);
  font-weight: 800;
  font-size: clamp(25px, 4vw, 40px);
  line-height: 1.16;
  letter-spacing: -0.008em;
  color: var(--white);
  max-width: 24ch;
}

.page-about .about-chapter__body > p,
.page-about .about-assure__body > p {
  margin: 0 0 15px;
  max-width: 62ch;
  font-size: clamp(15px, 1.4vw, 16.5px);
  line-height: 1.92;
  color: var(--about-body-text);
}

.page-about .about-chapter__body a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(111, 242, 210, 0.45);
  transition: color var(--dur-1) var(--ease), border-color var(--dur-1) var(--ease);
}

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

/* 米白阅读区 */
.page-about .about-sheet {
  background: var(--paper);
  color: var(--ink);
  border-top: 1px solid var(--about-rule-soft);
}

.page-about .about-sheet .section-index {
  color: var(--moss);
}

.page-about .about-sheet .about-chapter__note {
  color: var(--clay);
}

.page-about .about-sheet .about-chapter__body h2,
.page-about .about-sheet .about-assure__body h2 {
  color: var(--ink);
}

.page-about .about-sheet .about-chapter__body > p,
.page-about .about-sheet .about-assure__body > p {
  color: var(--about-ink-text);
}

.page-about .about-sheet .about-chapter__body a {
  color: var(--moss);
  border-bottom-color: rgba(30, 74, 58, 0.45);
}

/* 时间轴 */
.page-about .about-timeline__head {
  display: grid;
  gap: 12px;
  grid-template-columns: minmax(0, 1fr);
  margin-bottom: clamp(26px, 4vw, 46px);
}

.page-about .about-timeline__intro {
  max-width: 60ch;
  margin: 0;
  font-size: clamp(15px, 1.4vw, 16.5px);
  line-height: 1.9;
  color: var(--about-body-text);
}

.page-about .about-axis {
  list-style: none;
  margin: 0;
  padding: 0 0 0 24px;
  border-left: 1px solid var(--about-rule);
  display: grid;
  gap: 0;
}

.page-about .about-axis__item {
  position: relative;
  padding-bottom: clamp(16px, 2.4vw, 24px);
}

.page-about .about-axis__item::before {
  content: "";
  position: absolute;
  left: -29px;
  top: 7px;
  width: 9px;
  height: 9px;
  background: var(--cyan);
  transform: rotate(45deg);
  box-shadow: 0 0 0 4px rgba(111, 242, 210, 0.13);
}

.page-about .about-axis details {
  border: 0;
}

.page-about .about-axis summary {
  position: relative;
  display: grid;
  gap: 4px;
  padding-right: 26px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-axis summary::after {
  content: "+";
  position: absolute;
  right: 0;
  top: 2px;
  font-family: var(--font-mono);
  font-size: 15px;
  line-height: 1;
  color: var(--stone);
  transition: color var(--dur-1) var(--ease);
}

.page-about .about-axis details[open] summary::after {
  content: "–";
  color: var(--orange);
}

.page-about .about-axis summary:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 6px;
}

.page-about .about-axis__year {
  font-family: var(--font-mono);
  font-size: clamp(20px, 2.4vw, 26px);
  line-height: 1.1;
  color: var(--white);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.01em;
}

.page-about .about-axis__title {
  font-size: 13.5px;
  letter-spacing: 0.02em;
  color: var(--cyan);
}

.page-about .about-axis details > p {
  margin: 12px 0 0;
  max-width: 46ch;
  font-size: 14px;
  line-height: 1.85;
  color: var(--about-body-text);
}

/* 团队矩阵 */
.page-about .about-roles {
  display: grid;
  gap: 1px;
  margin: clamp(18px, 2.6vw, 28px) 0;
  background: var(--about-rule-soft);
  border-block: 1px solid var(--about-rule-soft);
}

.page-about .about-role {
  background: var(--ink-2);
  transition: background var(--dur-2) var(--ease);
}

.page-about .about-role[open] {
  background: var(--moss);
}

.page-about .about-role summary {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 14px;
  padding: clamp(14px, 2vw, 20px);
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-role summary:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: -3px;
}

.page-about .about-role__name {
  font-family: var(--font-narrow);
  font-weight: 700;
  font-size: clamp(17px, 2vw, 20px);
  color: var(--white);
  letter-spacing: 0.01em;
}

.page-about .about-role__count {
  font-family: var(--font-mono);
  font-size: clamp(22px, 2.6vw, 28px);
  line-height: 1;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .about-role[open] .about-role__count {
  color: var(--orange);
}

.page-about .about-role p {
  margin: 0;
  padding: 0 clamp(14px, 2vw, 20px) clamp(16px, 2vw, 22px);
  max-width: 52ch;
  font-size: 14px;
  line-height: 1.85;
  color: var(--about-body-text);
}

.page-about .about-role[open] p {
  color: rgba(242, 237, 226, 0.88);
}

.page-about .about-team__note {
  margin: 0;
  padding-left: 14px;
  border-left: 2px solid var(--cyan);
  max-width: 56ch;
  font-size: 14px !important;
  line-height: 1.85 !important;
  color: var(--about-body-text);
}

/* 内容体系 */
.page-about .about-flow {
  list-style: none;
  margin: clamp(18px, 2.6vw, 28px) 0;
  padding: 0;
  display: grid;
  gap: clamp(16px, 2.2vw, 24px);
}

.page-about .about-flow li {
  padding-top: 14px;
  border-top: 1px solid var(--about-rule);
}

.page-about .about-flow__key {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .about-flow h3 {
  margin: 8px 0 8px;
  font-family: var(--font-narrow);
  font-weight: 700;
  font-size: clamp(18px, 2.1vw, 22px);
  color: var(--white);
  letter-spacing: 0.01em;
}

.page-about .about-flow p {
  margin: 0;
  max-width: 50ch;
  font-size: 15px;
  line-height: 1.88;
  color: var(--about-body-text);
}

.page-about .about-system__links {
  font-size: 14px !important;
  line-height: 1.9 !important;
}

/* 质量保障 */
.page-about .about-assure__grid {
  display: grid;
  gap: clamp(22px, 3vw, 40px);
  grid-template-columns: minmax(0, 1fr);
}

.page-about .about-assure__body .section-index {
  margin-bottom: 12px;
}

.page-about .about-assure__list {
  list-style: none;
  margin: clamp(16px, 2.4vw, 26px) 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .about-assure__list li {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 10px;
  align-items: baseline;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--about-ink-rule);
  font-size: 14px;
  line-height: 1.8;
  color: var(--about-ink-text);
}

.page-about .about-assure__list span {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--moss);
}

.page-about .about-assure__media {
  margin: 0;
  border: 1px solid var(--about-ink-rule);
  overflow: hidden;
}

.page-about .about-assure__media img {
  width: 100%;
  object-fit: cover;
}

/* 视觉与社区（斜切模块） */
.page-about .about-stand__inner {
  position: relative;
  overflow: hidden;
  padding: clamp(24px, 4vw, 56px);
  background: linear-gradient(135deg, var(--moss), var(--ink-2) 66%);
  border: 1px solid var(--about-rule);
}

.page-about .about-stand__inner::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(
    116deg,
    transparent 52%,
    rgba(111, 242, 210, 0.14) 52.3%,
    rgba(111, 242, 210, 0.03) 74%,
    transparent 74.2%
  );
  pointer-events: none;
}

.page-about .about-stand__quote {
  position: relative;
  margin: 0 0 clamp(16px, 2.4vw, 26px);
  max-width: 26ch;
  font-family: var(--font-narrow);
  font-weight: 800;
  font-size: clamp(20px, 3.1vw, 32px);
  line-height: 1.42;
  color: var(--white);
}

.page-about .about-stand__copy {
  position: relative;
  margin: 0 0 clamp(20px, 3vw, 32px);
  max-width: 58ch;
  font-size: clamp(14.5px, 1.35vw, 16px);
  line-height: 1.9;
  color: rgba(242, 237, 226, 0.84);
}

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

.page-about .about-stand__facts > div {
  padding-top: 12px;
  border-top: 1px solid rgba(174, 184, 178, 0.3);
}

.page-about .about-stand__facts dt {
  margin: 0 0 5px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--cyan);
}

.page-about .about-stand__facts dd {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--paper);
}

.page-about .about-stand__media {
  margin: clamp(18px, 2.6vw, 28px) 0 0;
  border: 1px solid var(--about-rule-soft);
  overflow: hidden;
}

.page-about .about-stand__media img {
  width: 100%;
  object-fit: cover;
}

/* 下一阶段 */
.page-about .about-next__list {
  list-style: none;
  margin: clamp(16px, 2.4vw, 26px) 0;
  padding: 0;
  display: grid;
  gap: clamp(16px, 2.2vw, 24px);
  counter-reset: about-next;
}

.page-about .about-next__list li {
  padding-top: 14px;
  border-top: 1px solid var(--about-rule);
}

.page-about .about-next__list h3 {
  margin: 0 0 8px;
  font-family: var(--font-narrow);
  font-weight: 700;
  font-size: clamp(17px, 2vw, 21px);
  color: var(--white);
  letter-spacing: 0.01em;
}

.page-about .about-next__list h3::before {
  counter-increment: about-next;
  content: counter(about-next, decimal-leading-zero) " / ";
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--orange);
}

.page-about .about-next__list p {
  margin: 0;
  max-width: 52ch;
  font-size: 15px;
  line-height: 1.88;
  color: var(--about-body-text);
}

.page-about .about-next__note {
  max-width: 56ch;
  font-size: 14px !important;
  line-height: 1.88 !important;
  color: var(--stone) !important;
}

.page-about .about-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(20px, 3vw, 30px);
}

.page-about .about-cta .btn {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 22px;
  font-size: 14px;
  letter-spacing: 0.04em;
  text-decoration: none;
  border-radius: 2px;
  transition: background var(--dur-2) var(--ease), color var(--dur-2) var(--ease),
    border-color var(--dur-2) var(--ease);
}

.page-about .about-cta .btn--primary {
  background: var(--cyan);
  color: var(--ink);
  border: 1px solid var(--cyan);
  font-weight: 600;
}

.page-about .about-cta .btn--primary:hover,
.page-about .about-cta .btn--primary:focus-visible {
  background: var(--cyan-bright);
  border-color: var(--cyan-bright);
}

.page-about .about-cta .btn--ghost {
  background: transparent;
  color: var(--paper);
  border: 1px solid var(--line-strong);
}

.page-about .about-cta .btn--ghost:hover,
.page-about .about-cta .btn--ghost:focus-visible {
  border-color: var(--cyan);
  color: var(--cyan);
}

.page-about .about-cta .btn:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}

/* 移动端补强 */
@media (max-width: 520px) {
  .page-about .about-figures {
    grid-template-columns: minmax(0, 1fr);
  }

  .page-about .about-chapter__aside {
    flex-wrap: wrap;
  }

  .page-about .about-stand__inner {
    padding-inline: 20px;
  }
}

/* 平板与桌面 */
@media (min-width: 760px) {
  .page-about .about-roles {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-stand__facts {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 20px;
  }

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

  .page-about .about-timeline__head {
    grid-template-columns: 96px minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-timeline__head .section-index {
    grid-row: 1 / span 2;
    padding-top: 8px;
  }
}

@media (min-width: 900px) {
  .page-about .about-masthead__grid {
    grid-template-columns: 92px minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-masthead__aside {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
    padding-top: 10px;
  }

  .page-about .about-masthead__media {
    grid-column: 1 / -1;
  }

  .page-about .about-chapter__grid {
    grid-template-columns: 148px minmax(0, 1fr);
  }

  .page-about .about-chapter__aside {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
    position: sticky;
    top: 96px;
    align-self: start;
  }

  .page-about .about-assure__grid {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
    align-items: center;
  }

  .page-about .about-axis {
    padding: 0;
    border-left: 0;
    border-top: 1px solid var(--about-rule);
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }

  .page-about .about-axis__item {
    padding: clamp(20px, 2.2vw, 28px) clamp(10px, 1.3vw, 20px) 0 0;
  }

  .page-about .about-axis__item::before {
    left: 0;
    top: -5px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition-duration: 1ms !important;
    animation-duration: 1ms !important;
  }
}

/* 打印友好 */
@media print {
  .page-about {
    background: #ffffff;
    color: #061a14;
  }

  .page-about .about-masthead__media::after,
  .page-about .about-stand__inner::before {
    display: none;
  }

  .page-about .about-chapter__aside {
    position: static;
  }

  .page-about .about-sheet {
    background: #ffffff;
  }

  .page-about .about-stand__inner {
    background: #ffffff;
    border-color: #cccccc;
  }

  .page-about .about-stand__quote,
  .page-about .about-stand__facts dd,
  .page-about .about-chapter__body h2,
  .page-about .about-flow h3,
  .page-about .about-next__list h3,
  .page-about .about-role__name,
  .page-about .about-axis__year,
  .page-about .about-figures dd,
  .page-about .about-masthead__body h1 {
    color: #061a14;
  }

  .page-about .about-stand__copy,
  .page-about .about-chapter__body > p,
  .page-about .about-role p,
  .page-about .about-assure__list li {
    color: #2a3a34;
  }

  .page-about .about-axis details[open] > p {
    display: block;
  }

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