.page-about {
  --about-gap: clamp(22px, 4vw, 44px);
  --about-sec-pad: clamp(26px, 4.5vw, 52px);
  display: block;
  background: var(--ink);
  color: var(--text);
  font-family: var(--font-body);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding-block: clamp(18px, 3vw, 34px) clamp(28px, 5vw, 58px);
  border-bottom: 1px solid var(--line);
  background-image:
    repeating-linear-gradient(
      90deg,
      transparent 0 79px,
      var(--line-soft) 79px 80px
    ),
    radial-gradient(120% 100% at 100% 0%, rgba(198, 255, 61, 0.1), transparent 62%);
  overflow: hidden;
}

.page-about .about-hero__inner {
  display: grid;
  gap: var(--about-gap);
  grid-template-columns: minmax(0, 1fr);
  align-items: end;
}

.page-about .about-hero h1 {
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(1.95rem, 5.2vw, 3.7rem);
  line-height: 1.08;
  letter-spacing: 0.01em;
  margin: 0.4em 0 0.55em;
  text-wrap: balance;
}

.page-about .about-hero .lede {
  margin: 0;
  max-width: 54ch;
  color: var(--muted);
  font-size: clamp(0.94rem, 1.6vw, 1.06rem);
  line-height: 1.85;
}

.page-about .board {
  position: relative;
  border: 1px solid var(--line);
  background: linear-gradient(160deg, var(--panel) 0%, var(--panel-2) 100%);
  padding: clamp(14px, 2.4vw, 22px);
}

.page-about .board::after {
  content: "";
  position: absolute;
  right: 0;
  bottom: 0;
  width: 0;
  height: 0;
  border-left: 42px solid transparent;
  border-bottom: 42px solid var(--lime);
  opacity: 0.55;
  pointer-events: none;
}

.page-about .board__caption {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.16em;
  color: var(--ice);
  text-transform: uppercase;
}

.page-about .board__cells {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border-top: 1px solid var(--line-soft);
  border-left: 1px solid var(--line-soft);
}

.page-about .board__cell {
  padding: clamp(10px, 2vw, 16px);
  border-right: 1px solid var(--line-soft);
  border-bottom: 1px solid var(--line-soft);
}

.page-about .board__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.5rem, 3.4vw, 2.1rem);
  font-weight: 600;
  line-height: 1;
  color: var(--lime);
  letter-spacing: -0.01em;
}

.page-about .board__label {
  display: block;
  margin-top: 7px;
  font-size: 0.76rem;
  letter-spacing: 0.06em;
  color: var(--muted);
}

/* ---------- 主体双栏 ---------- */
.page-about .about-body {
  padding-block: clamp(24px, 4.5vw, 58px);
}

.page-about .about-body__grid {
  display: grid;
  gap: clamp(22px, 4vw, 46px);
  grid-template-columns: minmax(0, 1fr);
}

/* 章节目录 */
.page-about .about-toc {
  border-top: 1px solid var(--line);
  padding-top: 12px;
}

.page-about .about-toc__title {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 0.66rem;
  letter-spacing: 0.2em;
  color: var(--muted);
}

.page-about .about-toc__list {
  list-style: none;
  margin: 0;
  padding: 0 0 4px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-toc__link {
  display: inline-block;
  padding: 7px 12px;
  font-size: 0.76rem;
  line-height: 1.2;
  white-space: nowrap;
  color: var(--muted);
  text-decoration: none;
  border: 1px solid var(--line);
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease),
    background-color 0.18s var(--ease);
}

.page-about .about-toc__link:hover,
.page-about .about-toc__link:focus-visible {
  color: var(--text);
  border-color: var(--line);
  background: var(--panel);
}

.page-about .about-toc__link[aria-current] {
  color: var(--lime);
  border-color: var(--lime);
  background: rgba(198, 255, 61, 0.08);
}

/* ---------- 章节 ---------- */
.page-about .about-sec {
  padding-block: var(--about-sec-pad);
  border-top: 1px solid var(--line);
  scroll-margin-top: 104px;
}

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

.page-about .about-sec h2 {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: clamp(1.35rem, 2.9vw, 2.05rem);
  line-height: 1.22;
  letter-spacing: 0.01em;
  margin: 0.32em 0 0.62em;
  text-wrap: balance;
}

.page-about .about-sec p {
  margin: 0 0 1.05em;
  max-width: 66ch;
  color: var(--muted);
  font-size: 0.96rem;
  line-height: 1.85;
}

.page-about .about-sec p strong {
  color: var(--text);
  font-weight: 600;
}

.page-about .about-sec h3 {
  font-family: var(--font-head);
  font-size: 1.02rem;
  font-weight: 600;
  letter-spacing: 0.03em;
  margin: 0 0 0.35em;
  color: var(--text);
}

.page-about .about-sec h3 + p,
.page-about .about-sec h3 ~ p {
  margin-bottom: 0;
}

/* ---------- 时间线 ---------- */
.page-about .tl {
  list-style: none;
  margin: clamp(18px, 3vw, 30px) 0 0;
  padding: 0;
  position: relative;
}

.page-about .tl::before {
  content: "";
  position: absolute;
  left: 14px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: var(--line);
}

.page-about .tl__item {
  position: relative;
  padding-left: 44px;
  padding-bottom: 22px;
}

.page-about .tl__item:last-child {
  padding-bottom: 0;
}

.page-about .tl__idx {
  position: absolute;
  left: 0;
  top: 0;
  width: 29px;
  height: 29px;
  display: grid;
  place-items: center;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--lime);
  border: 1px solid var(--line);
  background: var(--ink);
}

.page-about .tl__title {
  margin-top: 2px;
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: clamp(20px, 3vw, 32px) 0 0;
  border: 1px solid var(--line);
  background: var(--panel);
  overflow: hidden;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  filter: saturate(0.88) contrast(1.04);
}

.page-about .about-figure--banner img {
  aspect-ratio: 8 / 3;
}

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

.page-about .about-figure--tall img {
  aspect-ratio: 4 / 3;
}

.page-about .about-figure figcaption {
  padding: 10px 14px;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.02em;
  line-height: 1.6;
  color: var(--muted);
}

/* ---------- 索引层列表 ---------- */
.page-about .index-list {
  list-style: none;
  margin: clamp(18px, 3vw, 28px) 0 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .index-list__item {
  display: grid;
  grid-template-columns: 40px minmax(0, 1fr);
  gap: 12px;
  padding: 16px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .index-list__key {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.1em;
  color: var(--orange);
  padding-top: 3px;
}

.page-about .index-list__body h3 {
  margin-bottom: 0.3em;
}

/* ---------- 分屏 ---------- */
.page-about .split {
  display: grid;
  gap: clamp(18px, 3vw, 34px);
  grid-template-columns: minmax(0, 1fr);
  align-items: start;
}

.page-about .split .about-figure {
  margin-top: 0;
}

/* ---------- 量化指标 ---------- */
.page-about .qa-stats {
  list-style: none;
  margin: 18px 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.page-about .qa-stats li {
  background: var(--panel);
  padding: 12px 10px;
}

.page-about .qa-stats__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.15rem, 2.6vw, 1.55rem);
  font-weight: 600;
  line-height: 1;
  color: var(--ice);
}

.page-about .qa-stats__txt {
  display: block;
  margin-top: 6px;
  font-size: 0.72rem;
  line-height: 1.5;
  color: var(--muted);
}

/* ---------- 团队四格 ---------- */
.page-about .team-grid {
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin-top: clamp(18px, 3vw, 28px);
}

.page-about .team-cell {
  background: var(--panel);
  padding: clamp(14px, 2.4vw, 22px);
  min-height: 158px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  border-left: 2px solid transparent;
  transition: background-color 0.2s var(--ease), border-left-color 0.2s var(--ease);
}

.page-about .team-cell:hover {
  background: var(--panel-2);
  border-left-color: var(--lime);
}

.page-about .team-cell__num {
  font-family: var(--font-mono);
  font-size: clamp(2rem, 4.6vw, 2.9rem);
  font-weight: 600;
  line-height: 1;
  color: var(--lime);
}

.page-about .team-cell__name {
  font-size: 0.98rem;
  margin: 0;
}

.page-about .team-cell__desc {
  margin: 0;
  font-size: 0.8rem;
  line-height: 1.7;
  color: var(--muted);
  opacity: 0.72;
  transition: opacity 0.2s var(--ease);
}

.page-about .team-cell:hover .team-cell__desc {
  opacity: 1;
}

/* ---------- 合作生态 ---------- */
.page-about .eco {
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  margin-top: clamp(16px, 3vw, 26px);
  grid-template-columns: minmax(0, 1fr);
}

.page-about .eco__node {
  background: var(--panel);
  padding: clamp(14px, 2.4vw, 20px);
}

.page-about .eco__idx {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.12em;
  color: var(--ice);
  border: 1px solid var(--line);
  padding: 2px 7px;
  margin-bottom: 10px;
}

.page-about .eco__node p {
  font-size: 0.88rem;
  margin-bottom: 0;
}

.page-about .eco__out {
  margin: 0;
  padding: 10px 14px;
  border: 1px solid var(--line);
  border-top: 0;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  color: var(--orange);
  background: rgba(255, 127, 63, 0.06);
}

.page-about .season-list {
  list-style: none;
  margin: clamp(18px, 3vw, 28px) 0 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .season-list li {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 12px;
  align-items: start;
  padding: 13px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .season-list__key {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--lime);
  text-align: center;
  border: 1px solid var(--line);
  padding: 2px 0;
}

.page-about .season-list__txt {
  font-size: 0.9rem;
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 理由 ---------- */
.page-about .reasons {
  display: grid;
  gap: 14px;
  grid-template-columns: minmax(0, 1fr);
  margin-top: clamp(16px, 3vw, 26px);
}

.page-about .reason {
  border: 1px solid var(--line);
  border-left: 2px solid var(--orange);
  background: var(--panel-2);
  padding: clamp(14px, 2.4vw, 20px);
}

.page-about .reason__idx {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.14em;
  color: var(--orange);
  margin-bottom: 8px;
}

.page-about .reason p {
  margin-bottom: 0;
  font-size: 0.9rem;
}

/* ---------- 行动区 ---------- */
.page-about .about-cta {
  margin-top: clamp(22px, 3.5vw, 34px);
  padding: clamp(16px, 2.8vw, 24px);
  border: 1px solid var(--line);
  background:
    linear-gradient(120deg, rgba(108, 229, 255, 0.07), transparent 55%),
    var(--panel);
}

.page-about .about-cta p {
  margin-bottom: 16px;
  color: var(--text);
  font-size: 0.94rem;
}

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

/* ---------- 收尾摘要板 ---------- */
.page-about .about-outro {
  padding-bottom: clamp(30px, 5vw, 64px);
}

.page-about .about-outro__board {
  border: 1px solid var(--line);
  background:
    repeating-linear-gradient(
      135deg,
      transparent 0 22px,
      rgba(42, 75, 61, 0.16) 22px 23px
    ),
    var(--panel-2);
  padding: clamp(18px, 3.4vw, 34px);
}

.page-about .about-outro__board h2 {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: clamp(1.25rem, 2.6vw, 1.85rem);
  line-height: 1.3;
  margin: 0.3em 0 0.6em;
  max-width: 32ch;
}

.page-about .about-outro__board > p {
  margin: 0 0 20px;
  max-width: 62ch;
  font-size: 0.94rem;
  line-height: 1.85;
  color: var(--muted);
}

.page-about .outro-links {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  grid-template-columns: minmax(0, 1fr);
}

.page-about .outro-links__a {
  display: block;
  background: var(--ink);
  padding: 13px 16px;
  font-size: 0.86rem;
  color: var(--text);
  text-decoration: none;
  border-left: 2px solid transparent;
  transition: color 0.18s var(--ease), border-left-color 0.18s var(--ease),
    background-color 0.18s var(--ease);
}

.page-about .outro-links__a:hover,
.page-about .outro-links__a:focus-visible {
  color: var(--lime);
  border-left-color: var(--lime);
  background: var(--panel);
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .about-figure--banner img {
    aspect-ratio: 8 / 3;
  }

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

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

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

@media (min-width: 820px) {
  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
  }

  .page-about .split {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.86fr);
  }

  .page-about .team-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .index-list__item {
    grid-template-columns: 56px minmax(0, 1fr);
    gap: 18px;
    padding: 18px 0;
  }
}

@media (min-width: 1000px) {
  .page-about .about-body__grid {
    grid-template-columns: 202px minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-toc {
    position: sticky;
    top: 96px;
  }

  .page-about .about-toc__list {
    display: block;
    overflow: visible;
  }

  .page-about .about-toc__list li {
    margin-bottom: 2px;
  }

  .page-about .about-toc__link {
    display: block;
    white-space: normal;
    border: 0;
    border-left: 2px solid var(--line);
    padding: 8px 0 8px 12px;
    font-size: 0.8rem;
  }

  .page-about .about-toc__link:hover,
  .page-about .about-toc__link:focus-visible {
    background: transparent;
    border-left-color: var(--muted);
  }

  .page-about .about-toc__link[aria-current] {
    background: transparent;
    border-left-color: var(--lime);
    color: var(--lime);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .team-cell,
  .page-about .team-cell__desc,
  .page-about .about-toc__link,
  .page-about .outro-links__a {
    transition: none;
  }
}