.page-about {
  --about-rail-w: 236px;
  --about-sec-gap: clamp(2.4rem, 6vw, 4.2rem);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(1.4rem, 4vw, 2.6rem) 0 clamp(2rem, 5vw, 3.2rem);
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, rgba(47, 243, 225, 0.07) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(47, 243, 225, 0.07) 1px, transparent 1px);
  background-size: 64px 64px;
  -webkit-mask-image: radial-gradient(ellipse at 80% 0%, #000 0%, transparent 68%);
  mask-image: radial-gradient(ellipse at 80% 0%, #000 0%, transparent 68%);
  pointer-events: none;
}

.page-about .about-hero > .wrap {
  position: relative;
  z-index: 1;
}

.page-about .about-hero h1 {
  margin: 0.9rem 0 1rem;
  max-width: 16em;
  font-size: clamp(2rem, 6.2vw, 4rem);
  font-weight: 900;
  line-height: 1.14;
  letter-spacing: -0.02em;
  color: var(--text);
}

.page-about .about-em {
  color: var(--cyan);
  white-space: nowrap;
}

.page-about .about-hero .lede {
  max-width: 34em;
  margin: 0;
  color: var(--muted);
  font-size: 1.0625rem;
  line-height: 1.9;
}

.page-about .about-hero__facts {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(1.6rem, 4vw, 2.4rem) 0 0;
  padding: 0;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-m);
  overflow: hidden;
}

.page-about .about-hero__facts li {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  padding: 1rem 1.1rem;
  background: var(--ink-800);
}

.page-about .about-hero__num {
  font-size: clamp(1.5rem, 3.2vw, 2rem);
  font-weight: 500;
  line-height: 1.1;
  letter-spacing: 0.02em;
  color: var(--cyan);
}

.page-about .about-hero__cap {
  font-size: 0.8125rem;
  line-height: 1.5;
  color: var(--muted);
}

/* ---------- 主体两栏 ---------- */
.page-about .about-layout {
  display: block;
  padding-top: clamp(1rem, 3vw, 1.6rem);
  padding-bottom: clamp(2rem, 5vw, 3rem);
}

.page-about .about-rail {
  padding: 0 0 clamp(1rem, 3vw, 1.4rem);
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-rail__title {
  margin: 0 0 0.7rem;
  font-size: 0.75rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .about-rail__nav {
  display: flex;
  gap: 0.45rem;
  overflow-x: auto;
  padding-bottom: 0.45rem;
  scrollbar-width: thin;
}

.page-about .about-rail__link {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: baseline;
  gap: 0.4rem;
  padding: 0.45rem 0.85rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--muted);
  font-size: 0.875rem;
  line-height: 1.4;
  text-decoration: none;
  white-space: nowrap;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.page-about .about-rail__link .mono {
  font-size: 0.6875rem;
  color: var(--cyan);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  color: var(--text);
  border-color: var(--orange);
  background: rgba(255, 138, 61, 0.08);
}

.page-about .about-rail__note {
  margin: 0.9rem 0 0;
  max-width: 30em;
  font-size: 0.8125rem;
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 章节 ---------- */
.page-about .about-sec {
  padding: var(--about-sec-gap) 0;
  border-top: 1px solid var(--line-soft);
  scroll-margin-top: 96px;
}

.page-about .about-sec:first-child {
  border-top: 0;
  padding-top: clamp(1.6rem, 4vw, 2.4rem);
}

.page-about .about-sec__head {
  display: flex;
  align-items: flex-start;
  gap: clamp(0.75rem, 2vw, 1.25rem);
  margin-bottom: clamp(1.1rem, 3vw, 1.8rem);
}

.page-about .about-sec__num {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: clamp(1.9rem, 5vw, 2.9rem);
  font-weight: 500;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--cyan);
  opacity: 0.9;
}

.page-about .about-sec__title {
  margin: 0;
  font-size: clamp(1.35rem, 3.2vw, 2rem);
  font-weight: 700;
  line-height: 1.34;
  letter-spacing: -0.01em;
  color: var(--text);
}

.page-about .about-sec > p {
  margin: 0 0 1.1em;
  max-width: 34em;
  font-size: 1.0625rem;
  line-height: 1.9;
  color: var(--text);
}

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

.page-about .about-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem 1.4rem;
  margin-top: 1.4rem;
}

.page-about .about-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  color: var(--cyan);
  font-size: 0.9375rem;
  text-decoration: none;
  border-bottom: 1px solid rgba(47, 243, 225, 0.4);
  padding-bottom: 0.15rem;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-link::after {
  content: "→";
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  transition: transform var(--dur) var(--ease);
}

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

.page-about .about-link:hover::after {
  transform: translateX(3px);
}

/* ---------- 场景卡片 ---------- */
.page-about .scene-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.85rem;
  margin: 1.6rem 0 1.4rem;
}

.page-about .scene {
  position: relative;
  padding: 1.2rem 1.1rem 1.15rem;
  background: linear-gradient(170deg, var(--ink-800), var(--ink-900));
  border: 1px solid var(--line);
  border-radius: var(--radius-m);
  overflow: hidden;
}

.page-about .scene::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--cyan);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--dur) var(--ease);
}

.page-about .scene:hover::after {
  transform: scaleX(1);
}

.page-about .scene__tag {
  display: inline-block;
  padding: 0.2rem 0.55rem;
  border-radius: 999px;
  background: var(--grad);
  color: #fff;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.06em;
}

.page-about .scene h3 {
  margin: 0.7rem 0 0.35rem;
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.5;
  color: var(--text);
}

.page-about .scene p {
  margin: 0;
  font-size: 0.875rem;
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 三道校对 ---------- */
.page-about .steps {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.9rem;
  margin: 1.7rem 0 1.5rem;
}

.page-about .step {
  position: relative;
  padding: 1.4rem 1.15rem 1.15rem;
  background: var(--ink-800);
  border: 1px solid var(--line);
  border-radius: var(--radius-m);
  transition: transform var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .step:hover {
  transform: translateY(-3px);
  border-color: rgba(47, 243, 225, 0.45);
}

.page-about .step::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  border-radius: 3px 0 0 3px;
  background: var(--cyan);
}

.page-about .step:nth-child(2)::before {
  background: var(--orange);
}

.page-about .step:nth-child(3)::before {
  background: var(--grad);
}

.page-about .step__idx {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.18em;
  color: var(--cyan);
}

.page-about .step:nth-child(2) .step__idx {
  color: var(--orange);
}

.page-about .step:nth-child(3) .step__idx {
  color: #b98bff;
}

.page-about .step h3 {
  margin: 0.5rem 0 0.45rem;
  font-size: 1.0625rem;
  font-weight: 700;
  color: var(--text);
}

.page-about .step p {
  margin: 0;
  font-size: 0.875rem;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .step__who {
  display: inline-block;
  margin-top: 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.04em;
  color: var(--warn);
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: 1.6rem 0;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: var(--radius-m);
}

.page-about .about-figure--square img {
  aspect-ratio: 9 / 7;
}

/* ---------- 四项信息 ---------- */
.page-about .fact-list {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.6rem;
  margin: 1.3rem 0 0;
  padding: 0;
}

.page-about .fact-list li {
  padding: 0.85rem 0.9rem;
  border: 1px dashed var(--line);
  border-radius: var(--radius-s);
  background: rgba(13, 26, 43, 0.6);
}

.page-about .fact-list b {
  display: block;
  margin-bottom: 0.25rem;
  font-size: 0.9375rem;
  font-weight: 700;
  color: var(--text);
}

.page-about .fact-list span {
  display: block;
  font-size: 0.78rem;
  line-height: 1.65;
  color: var(--muted);
}

/* ---------- 团队 ---------- */
.page-about .team-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.8rem;
  margin: 1.6rem 0;
}

.page-about .team-card {
  padding: 1.1rem 1rem;
  background: linear-gradient(165deg, var(--ink-800), rgba(7, 14, 26, 0.92));
  border: 1px solid var(--line);
  border-radius: var(--radius-m);
  transition: border-color var(--dur) var(--ease);
}

.page-about .team-card:hover {
  border-color: rgba(255, 138, 61, 0.55);
}

.page-about .team-card__num {
  display: block;
  font-size: clamp(1.6rem, 3.4vw, 2.1rem);
  font-weight: 500;
  line-height: 1;
  color: var(--orange);
}

.page-about .team-card h3 {
  margin: 0.55rem 0 0.3rem;
  font-size: 0.9375rem;
  font-weight: 700;
  color: var(--text);
}

.page-about .team-card p {
  margin: 0;
  font-size: 0.8125rem;
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 时间线（折叠） ---------- */
.page-about .tl {
  position: relative;
  margin: 1.8rem 0 0;
  padding-left: 1.6rem;
}

.page-about .tl::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 0.9rem;
  bottom: 0.9rem;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan), var(--orange) 65%, rgba(255, 138, 61, 0));
}

.page-about .tl__item {
  position: relative;
  margin-bottom: 0.65rem;
  background: var(--ink-800);
  border: 1px solid var(--line);
  border-radius: var(--radius-m);
  overflow: hidden;
}

.page-about .tl__item::before {
  content: "";
  position: absolute;
  left: -1.6rem;
  top: 1.1rem;
  width: 11px;
  height: 11px;
  box-sizing: border-box;
  border: 2px solid var(--orange);
  border-radius: 50%;
  background: var(--ink-900);
}

.page-about .tl__trigger {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0.3rem 0.75rem;
  width: 100%;
  padding: 0.95rem 1.1rem;
  background: none;
  border: 0;
  color: var(--text);
  font: inherit;
  text-align: left;
  cursor: pointer;
}

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

.page-about .tl__year {
  font-size: 0.9375rem;
  letter-spacing: 0.06em;
  color: var(--orange);
}

.page-about .tl__label {
  font-size: 0.9375rem;
  font-weight: 700;
}

.page-about .tl__sign {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 1.1rem;
  line-height: 1;
  color: var(--cyan);
  transition: transform var(--dur) var(--ease);
}

.page-about .tl__trigger[aria-expanded="true"] .tl__sign {
  transform: rotate(45deg);
}

.page-about .tl__summary {
  flex-basis: 100%;
  margin-top: 0.35rem;
  font-size: 0.8125rem;
  line-height: 1.7;
  color: var(--muted);
}

.page-about .tl__panel {
  border-top: 1px solid var(--line-soft);
}

.page-about .tl__panel .fold__inner {
  padding: 0.9rem 1.1rem 1.1rem;
}

.page-about .tl__panel p {
  margin: 0;
  font-size: 0.875rem;
  line-height: 1.85;
  color: var(--text);
}

/* ---------- 纠错路径 ---------- */
.page-about .path {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.55rem;
  margin: 1.5rem 0;
}

.page-about .path__node {
  padding: 0.6rem 0.9rem;
  border: 1px solid var(--line);
  border-radius: var(--radius-s);
  background: var(--ink-800);
  font-size: 0.8125rem;
  line-height: 1.5;
  color: var(--text);
}

.page-about .path__node--start {
  border-color: rgba(47, 243, 225, 0.55);
  color: var(--cyan);
}

.page-about .path__node--done {
  border-color: rgba(70, 224, 138, 0.55);
  color: var(--green);
}

.page-about .path__arrow {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  color: var(--orange);
}

/* ---------- 引用块 ---------- */
.page-about .pull {
  position: relative;
  margin: 1.6rem 0;
  padding: 1rem 1.2rem 1rem 1.45rem;
  max-width: 34em;
  border-radius: var(--radius-m);
  background: rgba(124, 77, 255, 0.1);
  font-size: 0.9375rem;
  line-height: 1.85;
  color: var(--text);
}

.page-about .pull::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.65rem;
  bottom: 0.65rem;
  width: 3px;
  border-radius: 3px;
  background: var(--grad);
}

/* ---------- 尾部行动 ---------- */
.page-about .about-tail {
  padding-bottom: clamp(2.4rem, 6vw, 4rem);
}

.page-about .about-cta {
  padding: clamp(1.6rem, 4vw, 2.6rem);
  border: 1px solid var(--line);
  border-radius: var(--radius-l);
  background:
    radial-gradient(120% 140% at 100% 0%, rgba(47, 243, 225, 0.14), transparent 55%),
    radial-gradient(100% 130% at 0% 100%, rgba(255, 138, 61, 0.12), transparent 55%),
    var(--ink-800);
}

.page-about .about-cta h2 {
  margin: 0 0 0.6rem;
  font-size: clamp(1.3rem, 3vw, 1.8rem);
  font-weight: 700;
  line-height: 1.35;
  color: var(--text);
}

.page-about .about-cta p {
  margin: 0;
  max-width: 32em;
  font-size: 0.9375rem;
  line-height: 1.85;
  color: var(--muted);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  margin-top: 1.4rem;
}

/* ---------- 断点 ---------- */
@media (min-width: 640px) {
  .page-about .scene-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

@media (min-width: 820px) {
  .page-about .steps {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

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

@media (min-width: 1024px) {
  .page-about .about-layout {
    display: grid;
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: clamp(2.4rem, 5vw, 4.4rem);
    align-items: start;
    padding-top: clamp(2rem, 4vw, 3rem);
  }

  .page-about .about-rail {
    position: sticky;
    top: 96px;
    padding: 0;
    border-bottom: 0;
  }

  .page-about .about-rail__nav {
    flex-direction: column;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .about-rail__link {
    padding: 0.5rem 0 0.5rem 0.9rem;
    border: 0;
    border-left: 2px solid var(--line);
    border-radius: 0;
    background: none;
    white-space: normal;
    font-size: 0.9375rem;
    transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
  }

  .page-about .about-rail__link:hover,
  .page-about .about-rail__link:focus-visible {
    background: none;
    border-left-color: var(--cyan);
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .scene::after,
  .page-about .step,
  .page-about .tl__sign,
  .page-about .about-link::after {
    transition: none;
  }
}