/* ============ 平台介绍页 /introduction/ ============ */
.page-about {
  --about-rule: 1px solid var(--line);
  --about-rule-ink: 1px solid rgba(36, 30, 27, .16);
  background: var(--ink);
  color: var(--text);
  font-family: var(--font-sans);
}

.page-about .about-section[id] {
  scroll-margin-top: 62px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  background: var(--cream);
  color: var(--brown);
  padding: clamp(24px, 5vw, 48px) 0 clamp(48px, 8vw, 92px);
}

.page-about .about-hero__wedge {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  width: min(44%, 500px);
  background: linear-gradient(155deg, var(--graphite) 0%, var(--ink) 55%, var(--ink-deep) 100%);
  clip-path: polygon(32% 0, 100% 0, 100% 100%, 0 100%);
  pointer-events: none;
}

.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
}

.page-about .about-crumb {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 30px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: rgba(36, 30, 27, .55);
}

.page-about .about-crumb a {
  color: inherit;
  text-decoration: none;
  border-bottom: 1px solid transparent;
}

.page-about .about-crumb a:hover {
  color: var(--brown);
  border-bottom-color: currentColor;
}

.page-about .about-crumb__sep {
  color: rgba(36, 30, 27, .32);
}

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

.page-about .about-hero__title {
  margin: 0;
  max-width: 15ch;
  font-size: clamp(30px, 6.4vw, 58px);
  line-height: 1.08;
  letter-spacing: -.028em;
  font-weight: 700;
  color: var(--brown);
}

.page-about .about-hero__lede {
  margin: 22px 0 0;
  max-width: 46ch;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.9;
  color: rgba(36, 30, 27, .78);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 32px;
}

.page-about .about-hero__ghost {
  color: var(--brown);
  border-color: rgba(36, 30, 27, .3);
}

.page-about .about-hero__ghost:hover {
  background: rgba(36, 30, 27, .06);
  color: var(--brown);
}

@media (max-width: 719px) {
  .page-about .about-hero {
    padding-bottom: 112px;
  }

  .page-about .about-hero__wedge {
    width: 100%;
    height: 74px;
    top: auto;
    bottom: 0;
    clip-path: polygon(0 100%, 100% 0, 100% 100%);
    opacity: .94;
  }

  .page-about .about-hero__title {
    max-width: 100%;
  }
}

/* ---------- 通栏主图 ---------- */
.page-about .about-banner {
  margin: 0;
  padding: 0 0 22px;
  background: var(--ink-deep);
  border-bottom: var(--about-rule);
}

.page-about .about-banner .figure__img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  filter: saturate(.6) contrast(1.06);
  opacity: .82;
}

.page-about .about-banner .figure__cap {
  padding: 14px var(--edge) 0;
  margin: 0 auto;
  max-width: var(--wrap);
  font-size: 13px;
  line-height: 1.7;
  color: var(--mist);
}

/* ---------- 章节索引条 ---------- */
.page-about .about-index {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(13, 31, 26, .95);
  border-bottom: var(--about-rule);
  backdrop-filter: blur(8px);
}

.page-about .about-index__track {
  display: flex;
  gap: 0;
  margin: 0 auto;
  max-width: var(--wrap);
  padding: 0 var(--edge);
  overflow-x: auto;
  scrollbar-width: none;
  -webkit-overflow-scrolling: touch;
}

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

.page-about .about-index .section-index__link {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 15px 16px;
  white-space: nowrap;
  font-size: 13.5px;
  line-height: 1.2;
  color: var(--mist);
  text-decoration: none;
  border-bottom: 2px solid transparent;
  transition: color .2s var(--ease), border-color .2s var(--ease);
}

.page-about .about-index .section-index__link:hover {
  color: var(--text);
}

.page-about .about-index .section-index__link.is-active,
.page-about .about-index .section-index__link[aria-current="true"] {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

.page-about .about-index .section-index__num {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--blue);
}

.page-about .about-index .section-index__link.is-active .section-index__num {
  color: var(--cyan);
}

/* ---------- 通用区块 ---------- */
.page-about .about-section {
  position: relative;
  padding: clamp(52px, 7.5vw, 100px) 0;
  border-top: var(--about-rule);
}

.page-about .about-index + .about-section {
  border-top: 0;
}

.page-about .about-section--graphite {
  background: var(--graphite);
}

.page-about .about-section--cream {
  background: var(--cream);
  color: var(--brown);
  border-top-color: rgba(36, 30, 27, .14);
}

.page-about .about-section--next {
  background:
    linear-gradient(180deg, rgba(63, 224, 206, .06) 0%, rgba(13, 31, 26, 0) 44%),
    var(--ink);
}

.page-about .about-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 14px;
  margin-bottom: 18px;
}

.page-about .about-head__num {
  font-size: 12px;
  letter-spacing: .2em;
  color: var(--cyan);
}

.page-about .about-section--cream .about-head__num {
  color: var(--orange);
}

.page-about .about-head h2 {
  flex: 1 1 300px;
  margin: 0;
  max-width: 26ch;
  font-size: clamp(23px, 3.6vw, 38px);
  line-height: 1.2;
  letter-spacing: -.022em;
  font-weight: 700;
  color: var(--cream);
}

.page-about .about-section--cream .about-head h2 {
  color: var(--brown);
}

.page-about .about-lede {
  margin: 0;
  max-width: 62ch;
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.9;
  color: var(--text);
}

.page-about .about-section--cream .about-lede {
  color: rgba(36, 30, 27, .76);
}

.page-about .about-sub {
  margin: clamp(34px, 4.5vw, 52px) 0 14px;
  font-size: clamp(17px, 2vw, 20px);
  font-weight: 700;
  letter-spacing: -.012em;
  color: var(--cream);
}

/* ---------- 01 四类模块 ---------- */
.page-about .about-chain {
  margin-top: clamp(28px, 4vw, 44px);
  border-top: var(--about-rule);
}

.page-about .about-chain__item {
  display: grid;
  grid-template-columns: 42px minmax(0, 1fr);
  column-gap: 14px;
  row-gap: 6px;
  padding: 24px 0;
  border-bottom: var(--about-rule);
}

.page-about .about-chain__num {
  grid-row: 1 / span 2;
  padding-top: 4px;
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--blue);
}

.page-about .about-chain__title {
  grid-column: 2;
  margin: 0;
  font-size: clamp(17px, 2vw, 20px);
  font-weight: 700;
  letter-spacing: -.012em;
  color: var(--cream);
}

.page-about .about-chain__text {
  grid-column: 2;
  margin: 0;
  max-width: 68ch;
  font-size: 15.5px;
  line-height: 1.9;
  color: var(--text);
}

.page-about .about-chain__note {
  margin: 30px 0 0;
  padding-left: 16px;
  max-width: 64ch;
  border-left: 2px solid var(--orange);
  font-size: 15.5px;
  line-height: 1.9;
  color: var(--mist);
}

@media (min-width: 900px) {
  .page-about .about-chain__item {
    grid-template-columns: 64px minmax(150px, 220px) minmax(0, 1fr);
    column-gap: 24px;
    row-gap: 0;
    align-items: baseline;
  }

  .page-about .about-chain__num {
    grid-row: auto;
    padding-top: 0;
  }

  .page-about .about-chain__title {
    grid-column: 2;
  }

  .page-about .about-chain__text {
    grid-column: 3;
  }
}

/* ---------- 02 规模与字段 ---------- */
.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(28px, 4vw, 40px) 0 0;
  background: var(--line);
  border: var(--about-rule);
}

.page-about .about-stats .stat {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 22px 18px;
  background: var(--ink-deep);
}

.page-about .about-stats .stat__value {
  font-family: var(--font-mono);
  font-size: clamp(28px, 4.4vw, 44px);
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--cyan);
}

.page-about .about-stats .stat__label {
  font-size: 13px;
  line-height: 1.6;
  color: var(--mist);
}

@media (min-width: 860px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.page-about .about-fields {
  margin-top: 0;
}

@media (max-width: 640px) {
  .page-about .about-fields .data-table {
    width: 100%;
    min-width: 0;
    border-collapse: collapse;
  }

  .page-about .about-fields .data-table thead {
    display: none;
  }

  .page-about .about-fields .data-table tbody,
  .page-about .about-fields .data-table tr,
  .page-about .about-fields .data-table td {
    display: block;
    width: 100%;
  }

  .page-about .about-fields .data-table tr {
    padding: 16px 0;
    border-bottom: var(--about-rule);
  }

  .page-about .about-fields .data-table tr:last-child {
    border-bottom: 0;
  }

  .page-about .about-fields .data-table td {
    padding: 3px 0;
    border: 0;
    font-size: 14.5px;
    line-height: 1.8;
  }

  .page-about .about-fields .data-table td:first-child {
    margin-bottom: 4px;
    font-family: var(--font-mono);
    font-size: 13px;
    letter-spacing: .1em;
    color: var(--cyan);
  }

  .page-about .about-fields .data-table td:last-child {
    font-size: 13.5px;
    color: var(--mist);
  }
}

/* ---------- 03 数据链路 ---------- */
.page-about .about-process {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(28px, 4vw, 48px);
  margin-top: clamp(28px, 4vw, 44px);
  align-items: start;
}

.page-about .about-steps {
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: var(--about-rule);
  counter-reset: step;
}

.page-about .about-steps__item {
  position: relative;
  padding: 22px 0 22px 46px;
  border-bottom: var(--about-rule);
  counter-increment: step;
}

.page-about .about-steps__item::before {
  content: counter(step, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 25px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--orange);
}

.page-about .about-steps__item h3 {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 700;
  letter-spacing: -.012em;
  color: var(--cream);
}

.page-about .about-steps__item p {
  margin: 0;
  max-width: 60ch;
  font-size: 15.5px;
  line-height: 1.9;
  color: var(--text);
}

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

.page-about .about-process__figure .figure__img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  filter: saturate(.58) contrast(1.05);
  border: var(--about-rule);
}

.page-about .about-process__figure .figure__cap {
  margin-top: 12px;
  font-size: 13px;
  line-height: 1.75;
  color: var(--mist);
}

@media (min-width: 940px) {
  .page-about .about-process {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr);
  }
}

/* ---------- 04 版本演进 ---------- */
.page-about .about-timeline__banner {
  margin: clamp(28px, 4vw, 42px) 0 0;
}

.page-about .about-timeline__banner .figure__img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  filter: saturate(.45) contrast(1.08);
  opacity: .68;
  border: var(--about-rule);
}

.page-about .about-vers {
  margin: clamp(32px, 4.4vw, 50px) 0 0;
  padding: 0 0 0 28px;
  list-style: none;
  border-left: 1px solid var(--line);
}

.page-about .about-vers__item {
  position: relative;
  margin-bottom: 22px;
  padding-bottom: 20px;
  border-bottom: var(--about-rule);
}

.page-about .about-vers__item:last-child {
  margin-bottom: 0;
  padding-bottom: 0;
  border-bottom: 0;
}

.page-about .about-ver__sum {
  position: relative;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 12px;
  padding: 6px 0;
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-ver__dot {
  position: absolute;
  left: -34px;
  top: 13px;
  width: 13px;
  height: 13px;
  border-radius: 50%;
  background: var(--ink);
  border: 2px solid var(--cyan);
}

.page-about .about-ver__tag {
  padding: 3px 8px;
  border: 1px solid var(--line);
  border-radius: 2px;
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--cyan);
}

.page-about .about-ver__name {
  font-size: clamp(16px, 2vw, 19px);
  font-weight: 700;
  letter-spacing: -.012em;
  color: var(--cream);
}

.page-about .about-ver__sum::after {
  content: "＋";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--mist);
}

.page-about .about-ver[open] .about-ver__sum::after {
  content: "－";
}

.page-about .about-ver__body {
  padding: 12px 0 4px;
  max-width: 66ch;
}

.page-about .about-ver__body p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.9;
  color: var(--text);
}

/* ---------- 05 团队分工 ---------- */
.page-about .about-team {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
  margin-top: clamp(28px, 4vw, 44px);
  border-top: var(--about-rule-ink);
}

.page-about .about-team__card {
  display: grid;
  grid-template-columns: 58px minmax(0, 1fr);
  column-gap: 18px;
  row-gap: 6px;
  padding: 26px 0;
  border-bottom: var(--about-rule-ink);
}

.page-about .about-team__n {
  grid-row: 1 / span 2;
  font-size: clamp(26px, 3.6vw, 38px);
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--orange);
}

.page-about .about-team__card h3 {
  grid-column: 2;
  margin: 0;
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -.012em;
  color: var(--brown);
}

.page-about .about-team__card p {
  grid-column: 2;
  margin: 0;
  max-width: 60ch;
  font-size: 15.5px;
  line-height: 1.9;
  color: rgba(36, 30, 27, .76);
}

@media (min-width: 940px) {
  .page-about .about-team {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    border-bottom: var(--about-rule-ink);
  }

  .page-about .about-team__card {
    display: block;
    padding: 28px 24px;
    border-bottom: 0;
    border-right: var(--about-rule-ink);
  }

  .page-about .about-team__card:first-child {
    padding-left: 0;
  }

  .page-about .about-team__card:last-child {
    padding-right: 0;
    border-right: 0;
  }

  .page-about .about-team__n {
    display: block;
    margin-bottom: 14px;
  }

  .page-about .about-team__card h3 {
    margin-bottom: 10px;
  }
}

.page-about .about-aside {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
  margin: clamp(28px, 4vw, 40px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-aside li {
  position: relative;
  padding-left: 20px;
  font-size: 15px;
  line-height: 1.85;
  color: rgba(36, 30, 27, .72);
}

.page-about .about-aside li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 11px;
  width: 8px;
  height: 2px;
  background: var(--orange);
}

@media (min-width: 800px) {
  .page-about .about-aside {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 26px;
  }
}

/* ---------- 06 入口去向 ---------- */
.page-about .about-next {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin-top: clamp(28px, 4vw, 44px);
  background: var(--line);
  border: var(--about-rule);
}

.page-about .about-next__item {
  display: block;
  padding: 26px 22px 28px;
  background: var(--ink);
  color: inherit;
  text-decoration: none;
  transition: background .22s var(--ease);
}

.page-about .about-next__item:hover {
  background: var(--graphite);
}

.page-about .about-next__kicker {
  display: block;
  margin-bottom: 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--blue);
}

.page-about .about-next__item h3 {
  margin: 0 0 10px;
  font-size: 19px;
  font-weight: 700;
  letter-spacing: -.012em;
  color: var(--cream);
}

.page-about .about-next__item p {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--text);
}

.page-about .about-next__item::after {
  content: "→";
  display: block;
  margin-top: 16px;
  font-family: var(--font-mono);
  color: var(--cyan);
  transition: transform .22s var(--ease);
}

.page-about .about-next__item:hover::after {
  transform: translateX(6px);
}

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

@media (min-width: 1080px) {
  .page-about .about-next {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ---------- 动效偏好 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    animation: none !important;
    transition: none !important;
  }
}