/* ============ /introduction/ 页面专属样式 ============ */
.page-about {
  --ab-gap: clamp(26px, 4vw, 56px);
  --ab-pad-y: clamp(56px, 8vw, 104px);
  background: var(--ink);
  color: var(--text-dark);
}

.page-about * {
  box-sizing: border-box;
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(120% 80% at 88% 4%, rgba(232, 163, 61, .16) 0%, rgba(11, 16, 48, 0) 58%),
    radial-gradient(90% 70% at 4% 96%, rgba(255, 90, 31, .12) 0%, rgba(11, 16, 48, 0) 60%),
    var(--ink);
  color: var(--white);
  padding: clamp(102px, 16vh, 190px) 0 clamp(52px, 7vw, 88px);
}

.page-about .ab-hero::after {
  content: "";
  position: absolute;
  inset: auto 0 0 0;
  height: 1px;
  background: linear-gradient(90deg, rgba(255, 90, 31, .8), rgba(203, 216, 222, .12) 45%, rgba(203, 216, 222, 0));
}

.page-about .ab-hero__crumbs .crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  margin: 0 0 clamp(30px, 4.4vw, 56px);
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: rgba(255, 255, 255, .52);
}

.page-about .ab-hero__crumbs .crumbs li + li::before {
  content: "/";
  margin-right: 10px;
  color: var(--signal);
}

.page-about .ab-hero__crumbs .crumbs a {
  color: inherit;
  text-decoration: none;
  border-bottom: 1px solid rgba(255, 255, 255, .2);
}

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

.page-about .ab-hero__body {
  display: grid;
  gap: var(--ab-gap);
  align-items: end;
}

.page-about .ab-hero .eyebrow {
  color: rgba(255, 255, 255, .66);
  margin: 0 0 16px;
  letter-spacing: .16em;
}

.page-about .ab-hero__title {
  margin: 0 0 clamp(18px, 2.6vw, 30px);
  font-size: clamp(32px, 6vw, 72px);
  line-height: 1.06;
  letter-spacing: -.022em;
  font-weight: 900;
  color: var(--white);
  text-wrap: balance;
}

.page-about .ab-hero__lede {
  margin: 0 0 clamp(26px, 3.4vw, 40px);
  max-width: 54ch;
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.88;
  color: rgba(255, 255, 255, .76);
}

.page-about .ab-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.page-about .ab-hero__actions .btn--line {
  border: 1px solid var(--line-dark-strong);
  background: transparent;
  color: var(--white);
}

.page-about .ab-hero__actions .btn--line:hover,
.page-about .ab-hero__actions .btn--line:focus-visible {
  border-color: var(--signal);
  color: var(--signal);
}

.page-about .ab-hero__index {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  border-top: 1px solid var(--line-dark);
}

.page-about .ab-hero__index li {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 11px 0;
  border-bottom: 1px solid var(--line-dark);
  font-size: 14px;
  letter-spacing: .02em;
  color: rgba(255, 255, 255, .74);
}

.page-about .ab-hero__index .mono {
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--amber);
  min-width: 2.2em;
}

@media (min-width: 680px) {
  .page-about .ab-hero__index {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: 28px;
  }
}

@media (min-width: 980px) {
  .page-about .ab-hero__body {
    grid-template-columns: 7fr 4.2fr;
    column-gap: clamp(34px, 5vw, 80px);
  }

  .page-about .ab-hero__index {
    grid-template-columns: minmax(0, 1fr);
  }
}

/* ---------- 正文骨架 ---------- */
.page-about .ab-doc {
  display: grid;
  gap: clamp(30px, 4.4vw, 60px);
  padding-top: var(--ab-pad-y);
  padding-bottom: var(--ab-pad-y);
}

@media (min-width: 1040px) {
  .page-about .ab-doc {
    grid-template-columns: minmax(0, 198px) minmax(0, 1fr);
    column-gap: clamp(34px, 4.4vw, 78px);
    align-items: start;
  }
}

/* 侧边锚点栏 */
.page-about .ab-rail__title {
  margin: 0 0 14px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line-light);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--slate);
}

.page-about .ab-rail__list {
  list-style: none;
  margin: 0 0 18px;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 2px 8px;
}

.page-about .ab-rail__list a {
  display: block;
  padding: 9px 10px;
  border-left: 2px solid transparent;
  font-size: 13.5px;
  line-height: 1.5;
  color: var(--text-dark);
  text-decoration: none;
  transition: background .22s var(--ease), border-color .22s var(--ease), color .22s var(--ease);
}

.page-about .ab-rail__list a:hover,
.page-about .ab-rail__list a:focus-visible {
  border-left-color: var(--signal);
  background: rgba(11, 16, 48, .05);
  color: var(--ink);
}

.page-about .ab-rail__note {
  margin: 0;
  padding: 12px 12px 12px 14px;
  border-left: 2px solid var(--amber);
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--text-mute);
}

@media (min-width: 1040px) {
  .page-about .ab-rail {
    position: sticky;
    top: 100px;
  }

  .page-about .ab-rail__list {
    grid-template-columns: minmax(0, 1fr);
  }
}

/* ---------- 章节 ---------- */
.page-about .ab-stream {
  display: grid;
  gap: clamp(58px, 8.5vw, 116px);
}

.page-about .ab-sec {
  scroll-margin-top: 112px;
}

.page-about .ab-sec__head {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding-bottom: 14px;
  margin-bottom: clamp(22px, 3vw, 34px);
  border-bottom: 1px solid var(--line-light);
}

.page-about .ab-sec__no {
  font-size: 12px;
  letter-spacing: .14em;
  font-weight: 700;
  color: var(--signal);
}

.page-about .ab-sec__title {
  margin: 0;
  font-size: clamp(24px, 3.4vw, 38px);
  line-height: 1.22;
  letter-spacing: -.012em;
  font-weight: 900;
  color: var(--ink);
}

.page-about .ab-sec__lede {
  margin: 0 0 clamp(24px, 3.2vw, 38px);
  max-width: 58ch;
  font-size: 16px;
  line-height: 1.85;
  color: var(--text-mute);
}

.page-about .ab-prose p {
  margin: 0 0 18px;
  font-size: 16px;
  line-height: 1.88;
  color: var(--text-dark);
}

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

.page-about .ab-prose a,
.page-about .ab-note a,
.page-about .ab-path a {
  color: var(--signal-deep);
  text-decoration: none;
  border-bottom: 1px solid rgba(255, 90, 31, .38);
}

.page-about .ab-prose a:hover,
.page-about .ab-note a:hover,
.page-about .ab-path a:hover {
  border-bottom-color: var(--signal);
}

.page-about .ab-note {
  margin: 22px 0 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--text-mute);
}

/* 双栏错落 */
.page-about .ab-block {
  display: grid;
  gap: clamp(24px, 3.2vw, 42px);
}

@media (min-width: 880px) {
  .page-about .ab-block {
    grid-template-columns: minmax(0, 1.55fr) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .ab-block--flip {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.55fr);
  }

  .page-about .ab-block--flip .ab-prose {
    padding-top: 6px;
  }
}

/* 数字卡 */
.page-about .ab-facts {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 2px;
  box-shadow: var(--shadow-soft);
}

.page-about .ab-facts li {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 16px 18px;
  border: 1px solid var(--line-light);
  background: var(--white);
}

.page-about .ab-facts__num {
  flex: 0 0 auto;
  min-width: 3.4em;
  font-size: clamp(26px, 3.2vw, 36px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--amber);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-facts--amber .ab-facts__num {
  color: var(--signal-deep);
}

.page-about .ab-facts__txt {
  font-size: 14px;
  line-height: 1.7;
  color: var(--text-mute);
}

/* 子块 */
.page-about .ab-sub {
  margin-top: clamp(30px, 4vw, 48px);
}

.page-about .ab-sub__title {
  margin: 0 0 10px;
  font-size: 17px;
  font-weight: 900;
  letter-spacing: .01em;
  color: var(--ink);
}

.page-about .ab-sub__lede {
  margin: 0 0 18px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--text-mute);
}

.page-about .ab-inline-num {
  color: var(--signal-deep);
  font-weight: 700;
}

.page-about .ab-chips {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .ab-chips li {
  padding: 8px 15px;
  border: 1px solid var(--line-light);
  background: var(--white);
  font-size: 13.5px;
  letter-spacing: .02em;
  color: var(--text-dark);
  transition: border-color .22s var(--ease), color .22s var(--ease);
}

.page-about .ab-chips li:hover {
  border-color: var(--signal);
  color: var(--ink);
}

/* 五步 */
.page-about .ab-steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  border-top: 1px solid var(--line-light);
}

.page-about .ab-steps li {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 2px;
  border-bottom: 1px solid var(--line-light);
  font-size: 15px;
  color: var(--text-dark);
}

.page-about .ab-steps__no {
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--slate);
  min-width: 2.4em;
}

@media (min-width: 720px) {
  .page-about .ab-steps {
    grid-template-columns: repeat(5, minmax(0, 1fr));
    gap: 0;
    border-top: none;
  }

  .page-about .ab-steps li {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
    padding: 18px 14px 18px 0;
    border-bottom: none;
    border-top: 2px solid var(--line-light);
  }

  .page-about .ab-steps li:first-child {
    border-top-color: var(--signal);
  }
}

/* ---------- 纵向阶段刻度 ---------- */
.page-about .ab-track {
  list-style: none;
  position: relative;
  margin: 0 0 clamp(30px, 4vw, 48px);
  padding: 0 0 0 28px;
  display: grid;
  gap: clamp(26px, 3.6vw, 42px);
}

.page-about .ab-track::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(180deg, var(--signal) 0%, var(--amber) 46%, var(--mist) 100%);
}

.page-about .ab-track__item {
  position: relative;
}

.page-about .ab-track__item::before {
  content: "";
  position: absolute;
  left: -28px;
  top: 5px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--paper);
  border: 2px solid var(--signal);
  transition: background .22s var(--ease), transform .22s var(--ease);
}

.page-about .ab-track__item:hover::before {
  background: var(--signal);
  transform: scale(1.18);
}

.page-about .ab-track__era {
  margin: 0 0 6px;
  font-size: 11px;
  letter-spacing: .22em;
  color: var(--slate);
}

.page-about .ab-track__name {
  margin: 0 0 8px;
  font-size: 18px;
  line-height: 1.4;
  font-weight: 900;
  color: var(--ink);
}

.page-about .ab-track__desc {
  margin: 0;
  max-width: 62ch;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--text-mute);
}

/* ---------- 图片 ---------- */
.page-about .ab-figure {
  margin: 0;
}

.page-about .ab-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--line-light);
  background: var(--ink-2);
}

.page-about .ab-figure figcaption {
  margin-top: 10px;
  font-size: 12px;
  letter-spacing: .02em;
  line-height: 1.7;
  color: var(--slate);
}

.page-about .ab-figure--lead img {
  aspect-ratio: 3 / 2;
}

@media (min-width: 880px) {
  .page-about .ab-figure--lead {
    margin-top: 4px;
  }
}

/* ---------- 团队分工网格 ---------- */
.page-about .ab-role-grid {
  list-style: none;
  margin: clamp(30px, 4vw, 48px) 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line-light);
  border: 1px solid var(--line-light);
}

.page-about .ab-role-grid li {
  padding: 20px 18px;
  background: var(--paper);
  transition: background .22s var(--ease), transform .22s var(--ease);
}

.page-about .ab-role-grid li:hover {
  background: var(--white);
  transform: translateY(-2px);
}

.page-about .ab-role-grid h3 {
  margin: 0 0 8px;
  font-size: 15px;
  font-weight: 900;
  letter-spacing: .02em;
  color: var(--ink);
}

.page-about .ab-role-grid p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--text-mute);
}

@media (min-width: 700px) {
  .page-about .ab-role-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 1100px) {
  .page-about .ab-role-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ---------- 深靛数字带 ---------- */
.page-about .ab-band-block {
  margin-top: clamp(28px, 3.6vw, 44px);
  display: grid;
  gap: 1px;
  background: var(--line-dark);
  border: 1px solid var(--ink-2);
}

.page-about .ab-band-block__item {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: clamp(20px, 2.6vw, 30px) clamp(18px, 2.2vw, 26px);
  background: var(--ink);
}

.page-about .ab-band-block__num {
  font-size: clamp(38px, 4.6vw, 58px);
  line-height: 1;
  font-weight: 700;
  letter-spacing: -.03em;
  color: var(--amber);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-band-block__label {
  font-size: 13px;
  line-height: 1.6;
  letter-spacing: .04em;
  color: rgba(255, 255, 255, .68);
}

@media (min-width: 700px) {
  .page-about .ab-band-block {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 1100px) {
  .page-about .ab-band-block {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ---------- 三类路径 ---------- */
.page-about .ab-paths {
  display: grid;
  gap: 1px;
  background: var(--line-light);
  border: 1px solid var(--line-light);
}

.page-about .ab-path {
  padding: clamp(22px, 3vw, 32px);
  background: var(--paper);
  transition: background .22s var(--ease);
}

.page-about .ab-path:hover {
  background: var(--white);
}

.page-about .ab-path__tag {
  display: inline-block;
  margin: 0 0 14px;
}

.page-about .ab-path__title {
  margin: 0 0 12px;
  font-size: 18px;
  line-height: 1.4;
  font-weight: 900;
  color: var(--ink);
}

.page-about .ab-path p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--text-mute);
}

@media (min-width: 900px) {
  .page-about .ab-paths {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

/* ---------- 联系提示 ---------- */
.page-about .ab-cta {
  margin-top: clamp(28px, 3.6vw, 44px);
  padding: clamp(22px, 3vw, 32px);
  border: 1px solid var(--line-light);
  border-left: 4px solid var(--signal);
  background: var(--white);
}

.page-about .ab-cta p {
  margin: 0 0 20px;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.85;
  color: var(--text-dark);
}

.page-about .ab-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ---------- 页脚上方地域带 ---------- */
.page-about .ab-skyline {
  background: var(--ink);
  padding: clamp(38px, 5.5vw, 72px) 0 clamp(46px, 6vw, 84px);
}

.page-about .ab-skyline img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--line-dark);
  opacity: .92;
}

.page-about .ab-skyline__cap {
  margin: 16px 0 0;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.8;
  letter-spacing: .03em;
  color: rgba(255, 255, 255, .5);
}

@media (min-width: 860px) {
  .page-about .ab-skyline__cap {
    max-width: 74ch;
  }
}

/* ---------- 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .ab-rail__list a,
  .page-about .ab-chips li,
  .page-about .ab-track__item::before,
  .page-about .ab-role-grid li,
  .page-about .ab-path {
    transition: none;
  }

  .page-about .ab-role-grid li:hover {
    transform: none;
  }
}