.page-about {
  --about-rail-w: 168px;
  --about-notch: 26px;
  background: var(--xt-ink);
  color: var(--xt-white);
  padding-bottom: clamp(56px, 9vw, 118px);
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumb {
  max-width: var(--xt-max);
  margin: 0 auto;
  padding: clamp(20px, 3vw, 34px) var(--xt-gutter) 0;
}

/* ---------- 首屏框景 ---------- */
.page-about .about-hero {
  max-width: var(--xt-max);
  margin: 0 auto;
  padding: clamp(22px, 4vw, 44px) var(--xt-gutter) 0;
}

.page-about .about-hero__frame {
  position: relative;
  padding: clamp(28px, 5vw, 62px) clamp(20px, 4vw, 56px) clamp(26px, 4vw, 50px);
  background:
    radial-gradient(120% 140% at 88% 0%, rgba(199, 255, 60, .10) 0%, transparent 58%),
    linear-gradient(180deg, rgba(199, 255, 60, .05) 0%, transparent 40%),
    var(--xt-charcoal);
  clip-path: polygon(
    0 0,
    calc(100% - var(--about-notch)) 0,
    100% var(--about-notch),
    100% 100%,
    var(--about-notch) 100%,
    0 calc(100% - var(--about-notch))
  );
}

.page-about .about-hero__frame::before,
.page-about .about-hero__frame::after {
  content: "";
  position: absolute;
  pointer-events: none;
  background: var(--xt-line-strong);
}

.page-about .about-hero__frame::before {
  top: 0;
  left: 0;
  width: clamp(60px, 12%, 140px);
  height: 1px;
  background: var(--xt-lime);
}

.page-about .about-hero__frame::after {
  right: clamp(0px, 4vw, 60px);
  bottom: 0;
  width: clamp(80px, 18%, 200px);
  height: 1px;
}

.page-about .about-hero__kicker {
  margin: 0 0 clamp(16px, 2.6vw, 26px);
  color: var(--xt-lime);
  font-size: 12px;
  letter-spacing: .16em;
}

.page-about .about-hero__title {
  margin: 0;
  font-family: var(--xt-head);
  font-weight: 900;
  font-size: clamp(30px, 5.6vw, 62px);
  line-height: 1.14;
  letter-spacing: -.02em;
  color: var(--xt-white);
}

.page-about .about-hero__lede {
  max-width: 40em;
  margin: clamp(20px, 3vw, 32px) 0 0;
  font-size: clamp(15.5px, 1.6vw, 17px);
  line-height: 1.85;
  color: var(--xt-silver);
}

.page-about .about-hero__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 22px 18px;
  margin-top: clamp(28px, 4vw, 46px);
  padding-top: clamp(22px, 3vw, 32px);
  border-top: 1px solid var(--xt-line);
}

.page-about .about-fact {
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-width: 0;
}

.page-about .about-fact__num {
  font-size: clamp(24px, 3.4vw, 38px);
  line-height: 1;
  color: var(--xt-lime);
  letter-spacing: .01em;
}

.page-about .about-fact__label {
  font-size: 13px;
  line-height: 1.6;
  color: var(--xt-muted);
}

/* ---------- 主体两栏骨架 ---------- */
.page-about .about-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(30px, 5vw, 54px);
  max-width: var(--xt-max);
  margin: clamp(44px, 7vw, 92px) auto 0;
  padding: 0 var(--xt-gutter);
}

/* ---------- 左侧索引列 ---------- */
.page-about .about-rail {
  border-left: 1px solid var(--xt-line);
  padding-left: 16px;
}

.page-about .about-rail__label {
  margin: 0 0 14px;
  font-size: 11px;
  letter-spacing: .2em;
  color: var(--xt-muted);
}

.page-about .about-rail__list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 18px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-rail__list a {
  display: inline-flex;
  align-items: baseline;
  gap: 7px;
  color: var(--xt-silver);
  font-size: 13.5px;
  text-decoration: none;
  padding-bottom: 2px;
  border-bottom: 1px solid transparent;
  transition: color .24s var(--xt-ease), border-color .24s var(--xt-ease);
}

.page-about .about-rail__list a:hover,
.page-about .about-rail__list a:focus-visible {
  color: var(--xt-lime);
  border-bottom-color: var(--xt-lime);
}

.page-about .about-rail__no {
  font-family: var(--xt-mono);
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--xt-muted);
}

.page-about .about-rail__list a:hover .about-rail__no {
  color: var(--xt-lime);
}

/* ---------- 内容流 ---------- */
.page-about .about-flow {
  min-width: 0;
}

.page-about .about-chapter {
  position: relative;
  padding-bottom: clamp(44px, 7vw, 88px);
}

.page-about .about-chapter--ruled {
  padding-top: clamp(40px, 6vw, 76px);
}

.page-about .about-chapter--ruled::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: min(100%, 560px);
  height: 1px;
  background: linear-gradient(90deg, var(--xt-line-strong), transparent);
  transform: rotate(-1.2deg);
  transform-origin: left center;
}

.page-about .about-chapter__index {
  margin: 0 0 14px;
  font-size: 11.5px;
  letter-spacing: .18em;
  color: var(--xt-lime);
}

.page-about .about-chapter__title {
  margin: 0;
  font-family: var(--xt-head);
  font-weight: 900;
  font-size: clamp(22px, 3.2vw, 34px);
  line-height: 1.28;
  letter-spacing: -.015em;
  color: var(--xt-white);
}

.page-about .about-chapter__lead {
  max-width: 34em;
  margin: 16px 0 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--xt-silver);
}

.page-about .about-chapter__tail {
  margin-top: clamp(24px, 3vw, 36px);
}

.page-about .about-narrow {
  max-width: 38em;
  margin-top: clamp(20px, 2.6vw, 28px);
}

.page-about .about-narrow p {
  margin: 0 0 1.05em;
  font-size: 16px;
  line-height: 1.85;
  color: var(--xt-silver);
}

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

.page-about .about-link {
  color: var(--xt-white);
  text-decoration: none;
  border-bottom: 1px solid var(--xt-line-strong);
  transition: color .24s var(--xt-ease), border-color .24s var(--xt-ease);
}

.page-about .about-link:hover,
.page-about .about-link:focus-visible {
  color: var(--xt-lime);
  border-bottom-color: var(--xt-lime);
}

/* ---------- 配图 ---------- */
.page-about .about-figure {
  margin: clamp(28px, 4vw, 46px) 0 0;
}

.page-about .about-figure__img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--xt-line);
  background: var(--xt-panel);
  clip-path: polygon(
    0 0,
    100% 0,
    100% calc(100% - 18px),
    calc(100% - 18px) 100%,
    0 100%
  );
}

.page-about .about-figure--bleed .about-figure__img {
  aspect-ratio: 14 / 9;
}

.page-about .about-figure--inset .about-figure__img {
  aspect-ratio: 3 / 2;
}

.page-about .about-figure--wide .about-figure__img {
  aspect-ratio: 2 / 1;
}

.page-about .about-figure__cap {
  margin: 12px 0 0;
  font-family: var(--xt-mono);
  font-size: 12px;
  line-height: 1.7;
  letter-spacing: .03em;
  color: var(--xt-muted);
}

/* ---------- 角色面板 ---------- */
.page-about .about-panel--roles {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin-top: clamp(26px, 3.6vw, 42px);
  background: var(--xt-line);
  border: 1px solid var(--xt-line);
}

.page-about .about-role {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  align-items: baseline;
  column-gap: 16px;
  row-gap: 8px;
  padding: 22px 20px;
  background: var(--xt-panel);
  transition: background .28s var(--xt-ease);
}

.page-about .about-role:hover {
  background: #1a2a20;
}

.page-about .about-role__no {
  font-size: clamp(22px, 3vw, 30px);
  line-height: 1;
  color: var(--xt-lime);
}

.page-about .about-role__name {
  font-family: var(--xt-head);
  font-weight: 700;
  font-size: 16px;
  color: var(--xt-white);
}

.page-about .about-role__note {
  grid-column: 1 / -1;
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--xt-muted);
}

/* ---------- 时间带 ---------- */
.page-about .about-timeline {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
  margin: clamp(28px, 4vw, 46px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 1px;
  background: linear-gradient(90deg, var(--xt-lime) 0%, rgba(199, 255, 60, .18) 62%, transparent 100%);
  transform: rotate(-1.4deg);
  transform-origin: left center;
  pointer-events: none;
}

.page-about .about-timeline__item {
  position: relative;
  padding: 26px 0 24px;
  border-bottom: 1px solid var(--xt-line);
}

.page-about .about-timeline__item:last-child {
  border-bottom: none;
}

.page-about .about-timeline__node {
  display: inline-block;
  font-family: var(--xt-mono);
  font-size: 11.5px;
  letter-spacing: .1em;
  color: var(--xt-lime);
  border: 1px solid rgba(199, 255, 60, .38);
  background: var(--xt-lime-soft);
  padding: 4px 10px 3px;
  transform: skewX(-7deg);
}

.page-about .about-timeline__title {
  margin: 14px 0 0;
  font-family: var(--xt-head);
  font-weight: 700;
  font-size: 17px;
  letter-spacing: -.01em;
  color: var(--xt-white);
}

.page-about .about-timeline__note {
  margin: 8px 0 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--xt-muted);
  transition: color .28s var(--xt-ease);
}

.page-about .about-timeline__item:hover .about-timeline__note {
  color: var(--xt-silver);
}

/* ---------- 合作方向 ---------- */
.page-about .about-partner-list {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
  margin: clamp(24px, 3.4vw, 38px) 0 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--xt-line);
}

.page-about .about-partner {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: baseline;
  column-gap: 14px;
  row-gap: 8px;
  padding: 20px 4px 20px;
  border-bottom: 1px solid var(--xt-line);
  transition: border-color .28s var(--xt-ease), padding-left .28s var(--xt-ease);
}

.page-about .about-partner:hover {
  border-bottom-color: var(--xt-lime);
  padding-left: 12px;
}

.page-about .about-partner__name {
  font-family: var(--xt-head);
  font-weight: 700;
  font-size: 16px;
  color: var(--xt-white);
}

.page-about .about-partner__count {
  font-size: 14px;
  letter-spacing: .04em;
  color: var(--xt-orange);
  white-space: nowrap;
}

.page-about .about-partner__note {
  grid-column: 1 / -1;
  margin: 0;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--xt-muted);
  transition: color .28s var(--xt-ease);
}

.page-about .about-partner:hover .about-partner__note {
  color: var(--xt-silver);
}

/* ---------- 认可引用块 ---------- */
.page-about .about-quote {
  position: relative;
  margin: clamp(28px, 4vw, 44px) 0 0;
  padding: 24px 24px 22px 28px;
  background: var(--xt-panel);
  border: 1px solid var(--xt-line);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 20px), calc(100% - 20px) 100%, 0 100%);
}

.page-about .about-quote::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 2px;
  height: 100%;
  background: var(--xt-lime);
}

.page-about .about-quote__text {
  margin: 0;
  font-family: var(--xt-head);
  font-weight: 700;
  font-size: clamp(16px, 2vw, 19px);
  line-height: 1.6;
  letter-spacing: -.01em;
  color: var(--xt-white);
}

.page-about .about-quote__meta {
  margin: 10px 0 0;
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--xt-muted);
}

/* ---------- 结尾引导 ---------- */
.page-about .about-cta {
  margin-top: clamp(26px, 3.6vw, 40px);
  padding-top: clamp(20px, 3vw, 30px);
  border-top: 1px dashed var(--xt-line);
}

.page-about .about-cta__text {
  max-width: 38em;
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--xt-silver);
}

/* ---------- 响应式 ---------- */
@media (min-width: 620px) {
  .page-about .about-hero__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-figure--bleed .about-figure__img {
    aspect-ratio: 16 / 9;
  }
}

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

  .page-about .about-timeline__item {
    padding: 28px 22px 30px 0;
    border-bottom: none;
  }

  .page-about .about-timeline__item + .about-timeline__item {
    padding-left: 26px;
    border-left: 1px solid var(--xt-line);
  }
}

@media (min-width: 1000px) {
  .page-about .about-shell {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: clamp(40px, 5vw, 76px);
  }

  .page-about .about-rail {
    align-self: start;
    position: sticky;
    top: 112px;
    padding-left: 18px;
  }

  .page-about .about-rail__list {
    flex-direction: column;
    flex-wrap: nowrap;
    gap: 13px;
  }

  .page-about .about-figure--bleed {
    max-width: calc(100% + 7%);
    margin-left: -3.5%;
  }

  .page-about .about-figure--inset {
    max-width: 88%;
  }

  .page-about .about-cta__text {
    font-size: 15.5px;
  }
}

@media (min-width: 1240px) {
  .page-about .about-figure--wide {
    max-width: calc(100% + 6%);
    margin-left: -6%;
  }

  .page-about .about-narrow {
    max-width: 40em;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition-duration: .01ms !important;
  }
}