.page-about {
  --about-line: rgba(245, 241, 232, 0.13);
  --about-line-strong: rgba(245, 241, 232, 0.28);
  --about-gap: clamp(16px, 2.4vw, 28px);
  position: relative;
  color: var(--paper);
  font-family: var(--font-sans);
  background:
    radial-gradient(1100px 640px at 84% -8%, rgba(200, 16, 46, 0.2), transparent 68%),
    radial-gradient(820px 560px at 2% 26%, rgba(0, 229, 255, 0.08), transparent 70%),
    linear-gradient(180deg, var(--ink-0) 0%, var(--ink-1) 46%, var(--ink-0) 100%);
}

/* ---------- 首屏分屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding-top: calc(var(--header-h) + clamp(30px, 5vw, 62px));
  padding-bottom: clamp(36px, 6vw, 78px);
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 4vw, 54px);
  align-items: end;
}

.page-about .about-hero__copy {
  min-width: 0;
}

.page-about .about-hero__kicker {
  margin: 18px 0 14px;
  color: var(--cyan);
}

.page-about .about-hero__title {
  margin: 0 0 18px;
  font-size: clamp(1.95rem, 5.4vw, 3.7rem);
  line-height: 1.06;
  font-weight: 900;
  letter-spacing: -0.02em;
}

.page-about .about-hero__title em {
  font-style: normal;
  color: var(--cyan);
}

.page-about .about-hero__lead {
  margin: 0;
  max-width: 36em;
  font-size: clamp(0.95rem, 1.5vw, 1.04rem);
  line-height: 1.68;
  color: var(--cool);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(22px, 3vw, 32px);
}

.page-about .about-hero__media {
  margin: 0;
  border: 1px solid var(--about-line-strong);
  background: var(--ink-2);
  overflow: hidden;
}

.page-about .about-hero__media .media__img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

/* ---------- 分栏骨架 ---------- */
.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 4vw, 52px);
  padding-bottom: clamp(48px, 7vw, 96px);
}

.page-about .about-rail {
  min-width: 0;
}

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

.page-about .toc__link {
  display: block;
  padding: 9px 12px;
  border-left: 2px solid rgba(168, 179, 189, 0.22);
  color: var(--cool);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  letter-spacing: 0.05em;
  text-decoration: none;
  transition: color 0.28s var(--ease), border-color 0.28s var(--ease), background 0.28s var(--ease);
}

.page-about .toc__link:hover {
  color: var(--paper);
  border-left-color: var(--orange);
}

.page-about .toc__link[aria-current="true"] {
  color: var(--cyan);
  border-left-color: var(--cyan);
  background: rgba(0, 229, 255, 0.07);
}

.page-about .about-rail__note {
  margin: 22px 0 0;
  padding-left: 14px;
  border-left: 2px solid var(--red-deep);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  line-height: 1.9;
  letter-spacing: 0.06em;
  color: var(--steel);
}

/* ---------- 章节流 ---------- */
.page-about .about-flow {
  display: grid;
  gap: clamp(42px, 6vw, 84px);
  min-width: 0;
}

.page-about .about-section {
  scroll-margin-top: calc(var(--header-h) + 26px);
  min-width: 0;
}

.page-about .about-head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  align-items: center;
  gap: clamp(12px, 2vw, 20px);
  margin-bottom: clamp(16px, 2.4vw, 26px);
  padding-bottom: 14px;
  border-bottom: 1px solid var(--about-line);
}

.page-about .about-head__num {
  font-family: var(--font-mono);
  font-size: clamp(1.7rem, 4.4vw, 2.7rem);
  line-height: 1;
  letter-spacing: -0.02em;
  color: transparent;
  -webkit-text-stroke: 1px rgba(200, 16, 46, 0.85);
}

.page-about .about-head__title {
  margin: 0;
  font-size: clamp(1.2rem, 2.5vw, 1.78rem);
  line-height: 1.26;
  font-weight: 800;
  letter-spacing: -0.01em;
}

.page-about .about-lead {
  margin: 0 0 clamp(18px, 2.6vw, 26px);
  max-width: 40em;
  font-size: 0.95rem;
  line-height: 1.7;
  color: var(--cool);
}

/* ---------- 纸张叠层卡片 ---------- */
.page-about .about-stack {
  padding: 10px 0 0 10px;
}

.page-about .about-sheet {
  position: relative;
  margin: 0;
  padding: clamp(20px, 3vw, 34px);
  border: 1px solid var(--about-line);
  background: linear-gradient(166deg, rgba(245, 241, 232, 0.075), rgba(245, 241, 232, 0.022) 62%);
}

.page-about .about-sheet::before {
  content: "";
  position: absolute;
  inset: 0;
  transform: translate(-10px, -10px);
  border: 1px solid rgba(200, 16, 46, 0.34);
  pointer-events: none;
}

.page-about .about-sheet p {
  position: relative;
  margin: 0 0 14px;
  max-width: 40em;
  font-size: 0.95rem;
  line-height: 1.72;
  color: rgba(245, 241, 232, 0.86);
}

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

/* ---------- 团队 ---------- */
.page-about .about-team {
  gap: var(--about-gap);
}

.page-about .about-role {
  min-width: 0;
  padding: clamp(18px, 2.4vw, 26px);
  background: linear-gradient(180deg, rgba(31, 38, 46, 0.94), rgba(21, 26, 32, 0.94));
}

.page-about .about-role h3 {
  margin: 12px 0 8px;
  font-size: 1.02rem;
  line-height: 1.4;
  font-weight: 800;
}

.page-about .about-role p {
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.68;
  color: var(--cool);
}

.page-about .about-team__media {
  margin: clamp(22px, 3vw, 32px) 0 0;
  border: 1px solid var(--about-line);
}

.page-about .about-team__media .media__img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
}

/* ---------- 流程 ---------- */
.page-about .about-split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 3vw, 34px);
}

.page-about .about-process__media {
  margin: 0;
  border: 1px solid var(--about-line);
}

.page-about .about-process__media .media__img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 5;
  object-fit: cover;
}

.page-about .about-steps {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 12px;
}

.page-about .about-steps li {
  padding: 16px 18px;
  border-left: 2px solid var(--red-deep);
  background: rgba(31, 38, 46, 0.52);
}

.page-about .about-steps__idx {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.16em;
  color: var(--orange);
}

.page-about .about-steps h3 {
  margin: 8px 0 6px;
  font-size: 1rem;
  line-height: 1.42;
  font-weight: 800;
}

.page-about .about-steps p {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.68;
  color: var(--cool);
}

/* ---------- 阶段时间轴 ---------- */
.page-about .about-timeline {
  display: flex;
  gap: 14px;
  overflow-x: auto;
  overscroll-behavior-x: contain;
  scroll-snap-type: x proximity;
  padding: 4px 2px 18px;
  border-top: 1px dashed rgba(168, 179, 189, 0.24);
  padding-top: 20px;
}

.page-about .about-stage {
  flex: 0 0 clamp(228px, 76vw, 300px);
  scroll-snap-align: start;
  position: relative;
  padding: 20px 16px 18px;
  border: 1px solid var(--about-line);
  border-top: 2px solid var(--red);
  background: linear-gradient(180deg, rgba(245, 241, 232, 0.055), rgba(245, 241, 232, 0.012));
  transition: transform 0.3s var(--ease), border-color 0.3s var(--ease), background 0.3s var(--ease);
}

.page-about .about-stage:hover,
.page-about .about-stage:focus-visible {
  transform: translateY(-3px);
  border-top-color: var(--cyan);
  background: linear-gradient(180deg, rgba(0, 229, 255, 0.09), rgba(245, 241, 232, 0.02));
  outline: none;
}

.page-about .about-stage__idx {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.16em;
  color: var(--orange);
}

.page-about .about-stage h3 {
  margin: 10px 0 8px;
  font-size: 1.02rem;
  line-height: 1.4;
  font-weight: 800;
}

.page-about .about-stage p {
  margin: 0;
  font-size: 0.88rem;
  line-height: 1.68;
  color: var(--cool);
}

/* ---------- 合作 ---------- */
.page-about .about-partners {
  gap: var(--about-gap);
}

.page-about .about-partner-card {
  min-width: 0;
  padding: 20px 18px;
  border: 1px solid var(--about-line);
  background: rgba(21, 26, 32, 0.72);
}

.page-about .about-partner-card h3 {
  margin: 12px 0 8px;
  font-size: 1.02rem;
  line-height: 1.42;
  font-weight: 800;
}

.page-about .about-partner-card p {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.68;
  color: var(--cool);
}

.page-about .about-link {
  display: inline-block;
  margin-top: 14px;
  padding-bottom: 2px;
  border-bottom: 1px solid rgba(0, 229, 255, 0.4);
  font-family: var(--font-mono);
  font-size: 0.76rem;
  letter-spacing: 0.08em;
  color: var(--cyan);
  text-decoration: none;
}

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

/* ---------- 数据速览 ---------- */
.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.page-about .about-stat {
  padding: 18px 14px;
  border: 1px solid var(--about-line);
  border-bottom: 2px solid var(--cyan);
  background: rgba(31, 38, 46, 0.62);
}

.page-about .about-stat:nth-child(2) {
  border-bottom-color: var(--orange);
}

.page-about .about-stat:nth-child(3) {
  border-bottom-color: var(--red);
}

.page-about .about-stat:nth-child(4) {
  border-bottom-color: rgba(245, 241, 232, 0.4);
}

.page-about .about-glance__note {
  margin: 18px 0 0;
  font-size: 0.86rem;
  line-height: 1.7;
  color: var(--cool);
  padding-left: 14px;
  border-left: 2px solid var(--cyan);
}

/* ---------- 收尾 ---------- */
.page-about .about-cta {
  margin-top: clamp(6px, 1vw, 14px);
  padding: clamp(22px, 3vw, 34px);
  border: 1px solid var(--about-line-strong);
  background: linear-gradient(120deg, rgba(200, 16, 46, 0.18), rgba(0, 229, 255, 0.06));
}

.page-about .about-cta p {
  margin: 0 0 16px;
  max-width: 38em;
  font-size: 0.95rem;
  line-height: 1.7;
  color: rgba(245, 241, 232, 0.9);
}

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

.page-about .about-to-top {
  position: fixed;
  right: clamp(14px, 3vw, 28px);
  bottom: clamp(14px, 3vw, 28px);
  z-index: 40;
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 16px;
  }

  .page-about .about-stat {
    padding: 22px 16px;
  }
}

@media (min-width: 860px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  }

  .page-about .about-hero__media {
    clip-path: polygon(0 4%, 100% 0, 100% 100%, 0 96%);
  }

  .page-about .about-split {
    grid-template-columns: minmax(0, 0.86fr) minmax(0, 1.14fr);
    align-items: start;
  }

  .page-about .about-timeline {
    overflow: visible;
    display: grid;
    grid-auto-flow: column;
    grid-auto-columns: minmax(0, 1fr);
    gap: 14px;
    padding-right: 2px;
  }

  .page-about .about-stage {
    flex: none;
  }
}

@media (min-width: 1000px) {
  .page-about .about-body {
    grid-template-columns: 216px minmax(0, 1fr);
    gap: clamp(34px, 4vw, 64px);
  }

  .page-about .about-rail__sticky {
    position: sticky;
    top: calc(var(--header-h) + 26px);
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .about-stage,
  .page-about .toc__link {
    transition: none;
  }

  .page-about .about-stage:hover,
  .page-about .about-stage:focus-visible {
    transform: none;
  }
}