.page-about {
  --about-rule: rgba(14, 43, 76, 0.14);
  --about-soft: rgba(14, 43, 76, 0.06);
  background-color: var(--haiou-white);
  color: var(--deep-blue);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(88px, 14vw, 168px) 0 clamp(34px, 6vw, 62px);
  background:
    radial-gradient(112% 82% at 92% 2%, rgba(232, 180, 74, 0.34), transparent 56%),
    radial-gradient(82% 72% at -6% 98%, rgba(47, 197, 182, 0.18), transparent 58%),
    var(--haiou-white);
}

.page-about .about-hero::after {
  content: "09";
  position: absolute;
  right: -0.06em;
  bottom: -0.22em;
  z-index: 0;
  font-family: var(--font-mono);
  font-size: clamp(120px, 26vw, 320px);
  line-height: 0.78;
  letter-spacing: -0.04em;
  color: rgba(14, 43, 76, 0.05);
  pointer-events: none;
  user-select: none;
}

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

.page-about .about-hero__eyebrow {
  margin: clamp(18px, 3vw, 30px) 0 0;
  color: var(--brick-red);
}

.page-about .about-hero__title {
  margin: 14px 0 0;
  max-width: 17em;
  font-size: clamp(32px, 5vw, 60px);
  font-weight: 900;
  line-height: 1.12;
  letter-spacing: -0.02em;
  text-shadow: 0 0 1px rgba(232, 180, 74, 0.6);
}

.page-about .about-hero__lede {
  margin: clamp(18px, 2.6vw, 28px) 0 0;
  max-width: 42em;
  font-size: 16.5px;
  line-height: 1.82;
}

/* 首屏数据带 */
.page-about .about-figures {
  list-style: none;
  margin: clamp(28px, 4.4vw, 46px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--about-rule);
  border: 1px solid var(--about-rule);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.page-about .about-figures li {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: clamp(14px, 2vw, 20px);
  background: var(--haiou-white);
}

.page-about .about-figures__num {
  font-size: clamp(26px, 3.4vw, 40px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--deep-blue);
}

.page-about .about-figures__unit {
  margin-left: 3px;
  font-size: 0.44em;
  font-weight: 500;
  letter-spacing: 0.04em;
  color: var(--gray-blue);
}

.page-about .about-figures__key {
  font-size: 12.5px;
  letter-spacing: 0.08em;
  color: var(--gray-blue);
}

/* ---------- 主体双列 ---------- */
.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 4vw, 40px);
  padding-bottom: clamp(40px, 7vw, 88px);
}

/* 索引列 */
.page-about .about-rail {
  padding: 14px 16px;
  border: 1px solid var(--about-rule);
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, 0.6);
}

.page-about .about-rail__title {
  margin: 0 0 10px;
  color: var(--brick-red);
}

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

.page-about .about-rail__list .index-list__item a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 12px;
  border: 1px solid var(--about-rule);
  border-radius: 999px;
  font-size: 13px;
  line-height: 1.2;
  white-space: nowrap;
  color: var(--deep-blue);
  text-decoration: none;
  transition: background 0.22s var(--ease), border-color 0.22s var(--ease), color 0.22s var(--ease);
}

.page-about .about-rail__list .index-list__item a:hover,
.page-about .about-rail__list .index-list__item a:focus-visible {
  background: var(--amber-light);
  border-color: rgba(232, 180, 74, 0.9);
}

.page-about .about-rail__list .index-list__num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--brick-red);
}

/* 正文 */
.page-about .about-essay {
  min-width: 0;
  max-width: 46em;
}

.page-about .about-chapter {
  scroll-margin-top: 112px;
}

.page-about .about-chapter + .about-chapter {
  margin-top: clamp(30px, 5vw, 58px);
  padding-top: clamp(30px, 5vw, 58px);
  border-top: 1px solid var(--about-rule);
}

.page-about .about-chapter__head {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 14px;
  margin: 0 0 clamp(14px, 2vw, 22px);
}

.page-about .about-chapter__num {
  font-size: clamp(30px, 4vw, 46px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--brick-red);
}

.page-about .about-chapter__title {
  margin: 0;
  font-size: clamp(21px, 2.6vw, 30px);
  font-weight: 800;
  line-height: 1.28;
  letter-spacing: -0.01em;
  text-shadow: 0 0 1px rgba(232, 180, 74, 0.55);
}

.page-about .about-chapter__body p {
  margin: 0 0 1em;
  max-width: 38em;
  font-size: 16.5px;
  line-height: 1.82;
}

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

.page-about .about-body-gap {
  margin-top: clamp(20px, 3vw, 30px) !important;
}

.page-about .about-marginnote {
  padding: 4px 0 4px 16px;
  border-left: 2px solid var(--brick-red);
  font-size: 15px !important;
  line-height: 1.78 !important;
  color: var(--gray-blue);
}

.page-about .about-brick-rule {
  display: block;
  height: 8px;
  margin: 0 0 clamp(20px, 3vw, 30px);
  border-radius: 2px;
  background-image: repeating-linear-gradient(
    90deg,
    var(--brick-red) 0 14px,
    rgba(168, 62, 42, 0.2) 14px 18px,
    transparent 18px 32px
  );
  opacity: 0.6;
}

/* 团队数字格 */
.page-about .about-stats {
  list-style: none;
  margin: clamp(20px, 3vw, 30px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--about-rule);
  border: 1px solid var(--about-rule);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.page-about .about-stats li {
  padding: clamp(14px, 2vw, 20px);
  background: var(--haiou-white);
}

.page-about .about-stats__num {
  display: block;
  font-size: clamp(23px, 3vw, 32px);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: 0.02em;
  color: var(--deep-blue);
}

.page-about .about-stats__unit {
  margin-left: 2px;
  font-size: 0.46em;
  font-weight: 500;
  color: var(--gray-blue);
}

.page-about .about-stats__key {
  display: block;
  margin-top: 8px;
  font-size: 12.5px;
  letter-spacing: 0.06em;
  color: var(--gray-blue);
}

/* 四步流程 */
.page-about .about-steps {
  list-style: none;
  margin: clamp(20px, 3vw, 30px) 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .about-step {
  display: grid;
  grid-template-columns: 26px minmax(0, 1fr);
  gap: 14px;
  padding: 16px 16px 16px 12px;
  border: 1px solid rgba(47, 197, 182, 0.34);
  border-left: 3px solid var(--electric-teal);
  border-radius: 0 var(--radius-xs) var(--radius-xs) 0;
  background: rgba(255, 255, 255, 0.62);
  transition: background 0.25s var(--ease), transform 0.25s var(--ease), border-color 0.25s var(--ease);
}

.page-about .about-step:hover,
.page-about .about-step:focus-within {
  background: rgba(47, 197, 182, 0.1);
  border-color: rgba(47, 197, 182, 0.7);
  transform: translateX(3px);
}

.page-about .about-step__dot {
  width: 12px;
  height: 12px;
  margin-top: 6px;
  justify-self: center;
  border-radius: 50%;
  background: var(--electric-teal);
  box-shadow: 0 0 0 4px rgba(47, 197, 182, 0.18);
}

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

.page-about .about-step__row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .about-step__title {
  margin: 0;
  font-size: 17px;
  font-weight: 800;
  letter-spacing: 0.01em;
  color: var(--deep-blue);
}

.page-about .about-step__time {
  padding: 2px 9px;
  border: 1px solid rgba(168, 62, 42, 0.36);
  border-radius: 999px;
  font-size: 11.5px;
  letter-spacing: 0.06em;
  color: var(--brick-red);
  opacity: 0.78;
  transition: opacity 0.25s var(--ease), background 0.25s var(--ease), color 0.25s var(--ease);
}

.page-about .about-step:hover .about-step__time,
.page-about .about-step:focus-within .about-step__time {
  opacity: 1;
  background: var(--brick-red);
  color: var(--haiou-white);
}

.page-about .about-step__text {
  margin: 9px 0 0;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--deep-blue);
}

/* 阶段时间轴 */
.page-about .about-timeline {
  list-style: none;
  position: relative;
  margin: clamp(20px, 3vw, 30px) 0 0;
  padding: 0 0 0 30px;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 8px;
  top: 12px;
  bottom: 12px;
  width: 2px;
  background: linear-gradient(180deg, var(--electric-teal), rgba(47, 197, 182, 0.12));
}

.page-about .about-timeline > li {
  position: relative;
}

.page-about .about-timeline > li + li {
  margin-top: 14px;
}

.page-about .about-timeline > li::before {
  content: "";
  position: absolute;
  left: -26px;
  top: 20px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--haiou-white);
  border: 2px solid var(--electric-teal);
}

.page-about .about-stage {
  border: 1px solid var(--about-rule);
  border-radius: var(--radius-xs);
  background: rgba(255, 255, 255, 0.62);
  overflow: hidden;
  transition: background 0.25s var(--ease), border-color 0.25s var(--ease);
}

.page-about .about-stage[open] {
  background: var(--amber-light);
  border-color: rgba(232, 180, 74, 0.85);
}

.page-about .about-stage__summary {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 12px;
  padding: 14px 16px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-stage__summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 18px;
  line-height: 1;
  color: var(--brick-red);
}

.page-about .about-stage[open] .about-stage__summary::after {
  content: "–";
}

.page-about .about-stage__year {
  font-size: 14.5px;
  letter-spacing: 0.04em;
  color: var(--brick-red);
}

.page-about .about-stage__name {
  font-size: 16px;
  font-weight: 700;
  color: var(--deep-blue);
}

.page-about .about-stage__detail {
  padding: 0 16px 16px;
}

.page-about .about-stage__detail p {
  margin: 0;
  max-width: 36em;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--deep-blue);
}

/* 图片 */
.page-about .about-figure {
  position: relative;
  margin: clamp(22px, 3.4vw, 34px) 0 0;
}

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

.page-about .about-figure .media__caption {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.62;
  color: var(--gray-blue);
}

.page-about .about-figure--tv {
  padding: 14px 14px 16px;
  border-radius: var(--radius);
  background: var(--ink-blue);
  box-shadow: var(--shadow-panel);
}

.page-about .about-figure--tv .media__caption {
  margin: 12px 2px 0;
  color: rgba(247, 244, 236, 0.72);
}

/* 收尾行动区 */
.page-about .about-cta {
  position: relative;
  padding: clamp(40px, 7vw, 84px) 0;
  background:
    radial-gradient(90% 80% at 88% 0%, rgba(47, 197, 182, 0.22), transparent 60%),
    var(--ink-blue);
  color: var(--haiou-white);
}

.page-about .about-cta__label {
  margin: 0;
  color: var(--tv-amber);
}

.page-about .about-cta__title {
  margin: 12px 0 0;
  max-width: 20em;
  font-size: clamp(22px, 3vw, 34px);
  font-weight: 800;
  line-height: 1.3;
  letter-spacing: -0.01em;
  color: var(--haiou-white);
}

.page-about .about-cta__text {
  margin: 14px 0 0;
  max-width: 40em;
  font-size: 16px;
  line-height: 1.8;
  color: rgba(247, 244, 236, 0.82);
}

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

.page-about .about-cta .btn--ghost {
  border-color: rgba(247, 244, 236, 0.42);
  color: var(--haiou-white);
}

.page-about .about-cta .btn--ghost:hover,
.page-about .about-cta .btn--ghost:focus-visible {
  border-color: var(--tv-amber);
  color: var(--tv-amber);
}

/* ---------- 桌面 ---------- */
@media (min-width: 760px) {
  .page-about .about-figures {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 960px) {
  .page-about .about-layout {
    grid-template-columns: minmax(0, 1fr) 226px;
    grid-template-areas: "essay rail";
    gap: clamp(34px, 5vw, 74px);
    align-items: start;
  }

  .page-about .about-essay {
    grid-area: essay;
  }

  .page-about .about-rail {
    grid-area: rail;
    position: sticky;
    top: 104px;
    padding: 4px 0 4px 18px;
    border: 0;
    border-left: 2px solid rgba(14, 43, 76, 0.12);
    border-radius: 0;
    background: transparent;
  }

  .page-about .about-rail__title {
    margin-bottom: 12px;
  }

  .page-about .about-rail__list {
    flex-direction: column;
    gap: 2px;
    overflow: visible;
  }

  .page-about .about-rail__list .index-list__item a {
    width: 100%;
    padding: 7px 9px;
    border: 0;
    border-radius: 4px;
    white-space: normal;
    font-size: 14px;
    color: var(--gray-blue);
  }
}

@media (min-width: 1180px) {
  .page-about .about-chapter__head {
    gap: 20px;
  }
}

/* ---------- 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .about-step,
  .page-about .about-step__time,
  .page-about .about-rail__list .index-list__item a,
  .page-about .about-stage {
    transition: none;
  }

  .page-about .about-step:hover,
  .page-about .about-step:focus-within {
    transform: none;
  }
}