.page-about {
  --about-rail: 96px;
  --about-scan: rgba(230, 237, 245, 0.045);
  display: block;
  background: var(--navy-900);
  color: var(--paper);
}

.page-about .about-crumb {
  padding: clamp(18px, 3vw, 26px) 0 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--mist);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(22px, 4vw, 40px) 0 clamp(32px, 6vw, 60px);
  border-bottom: 1px solid var(--line);
  background:
    radial-gradient(90% 70% at 88% 0%, rgba(47, 224, 208, 0.12), transparent 62%),
    radial-gradient(70% 60% at 0% 100%, rgba(245, 184, 74, 0.07), transparent 70%),
    linear-gradient(180deg, var(--navy-800) 0%, var(--navy-900) 78%);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: repeating-linear-gradient(
    180deg,
    var(--about-scan) 0 1px,
    transparent 1px 5px
  );
}

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

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 22px;
}

.page-about .about-hero__rail {
  display: none;
}

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

.page-about .about-hero__eyebrow {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--aqua);
}

.page-about .about-hero h1 {
  margin: 0 0 18px;
  font-family: var(--font-display);
  font-size: clamp(29px, 6vw, 54px);
  line-height: 1.12;
  letter-spacing: 0.015em;
  color: var(--paper);
  max-width: 20ch;
}

.page-about .about-hero__lead {
  margin: 0;
  max-width: 60ch;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--mist);
}

.page-about .about-hero__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 26px 0 0;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-hero__fact {
  background: rgba(10, 20, 36, 0.78);
  padding: 13px 15px 15px;
}

.page-about .about-hero__fact dt {
  margin: 0 0 6px;
  font-size: 11.5px;
  letter-spacing: 0.1em;
  color: var(--mist);
}

.page-about .about-hero__fact dd {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(15px, 2.4vw, 19px);
  letter-spacing: 0.02em;
  color: var(--paper);
}

.page-about .about-hero__fact--amber dd {
  color: var(--amber);
}

.page-about .about-hero__figure {
  margin-top: clamp(28px, 5vw, 46px);
}

/* ---------- 正文骨架 ---------- */
.page-about .about-body {
  padding: clamp(28px, 5vw, 56px) 0 clamp(44px, 7vw, 84px);
}

.page-about .about-side {
  min-width: 0;
  margin-bottom: 30px;
}

.page-about .about-toc__no {
  display: inline-block;
  width: 2.4em;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--amber);
}

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

/* ---------- 章节 ---------- */
.page-about .about-section {
  min-width: 0;
}

.page-about .about-section + .about-section {
  margin-top: clamp(40px, 7vw, 74px);
  padding-top: clamp(28px, 4vw, 46px);
  border-top: 1px solid var(--line);
}

.page-about .about-section__head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  align-items: baseline;
  gap: 14px;
  margin-bottom: 18px;
}

.page-about .about-section__no {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.14em;
  color: var(--amber);
}

.page-about .about-section__title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(21px, 3.4vw, 30px);
  line-height: 1.28;
  letter-spacing: 0.02em;
  color: var(--paper);
}

.page-about .about-section__lead {
  margin: 0 0 20px;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.85;
  color: var(--mist);
}

.page-about .about-section__lead--after {
  margin: 22px 0 0;
}

/* ---------- 时间轴 ---------- */
.page-about .about-timeline {
  list-style: none;
  position: relative;
  margin: 0;
  padding: 0 0 0 28px;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 10px;
  width: 1px;
  background: linear-gradient(180deg, var(--aqua) 0%, var(--line) 62%, transparent 100%);
}

.page-about .about-timeline__item {
  position: relative;
  padding: 0 0 22px;
}

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

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: -25px;
  top: 7px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--navy-900);
  border: 1px solid var(--aqua);
  box-shadow: 0 0 0 3px rgba(47, 224, 208, 0.1);
}

.page-about .about-timeline__when {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.08em;
  color: var(--amber);
}

.page-about .about-timeline__what {
  margin: 0;
  max-width: 62ch;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--paper);
}

/* ---------- 三类记录 ---------- */
.page-about .about-method {
  list-style: none;
  display: grid;
  gap: 1px;
  margin: 0;
  padding: 0;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-method__item {
  position: relative;
  background: var(--navy-800);
  padding: clamp(18px, 3vw, 26px) clamp(16px, 3vw, 24px);
}

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

.page-about .about-method__item--amber::before {
  background: var(--amber);
}

.page-about .about-method__item--rose::before {
  background: var(--rose);
}

.page-about .about-method__no {
  display: block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 28px;
  line-height: 1;
  color: rgba(230, 237, 245, 0.16);
}

.page-about .about-method__name {
  margin: 0 0 9px;
  font-size: 16px;
  font-weight: 500;
  letter-spacing: 0.02em;
  color: var(--paper);
}

.page-about .about-method__text {
  margin: 0 0 14px;
  font-size: 14px;
  line-height: 1.85;
  color: var(--mist);
}

.page-about .about-method__meta {
  display: block;
  padding-top: 10px;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.06em;
  color: var(--aqua);
}

.page-about .about-method__item--amber .about-method__meta {
  color: var(--amber);
}

/* ---------- 核对步骤 ---------- */
.page-about .about-steps {
  list-style: none;
  display: grid;
  gap: 10px;
  margin: 0 0 24px;
  padding: 0;
}

.page-about .about-steps li {
  background: var(--navy-700);
  border: 1px solid var(--line);
  padding: 15px 16px 17px;
  font-size: 14px;
  line-height: 1.8;
  color: var(--mist);
}

.page-about .about-steps__no {
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--amber);
}

.page-about .about-steps strong {
  color: var(--paper);
  font-weight: 500;
}

.page-about .table-wrap {
  max-width: 100%;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-team__group {
  background: var(--navy-800);
  padding: clamp(16px, 3vw, 22px);
}

.page-about .about-team__idx {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--rose);
}

.page-about .about-team__name {
  margin: 0 0 8px;
  font-size: 15.5px;
  font-weight: 500;
  letter-spacing: 0.02em;
  color: var(--paper);
}

.page-about .about-team__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.85;
  color: var(--mist);
}

.page-about .about-team__foot {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  align-items: center;
  gap: 18px;
  margin-top: 16px;
  padding: 18px 0 0;
  border-top: 1px dashed var(--line);
}

.page-about .about-team__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(34px, 7vw, 48px);
  line-height: 1;
  color: var(--amber);
}

.page-about .about-team__foot-text {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--mist);
}

/* ---------- 编号短句列表 ---------- */
.page-about .about-points {
  list-style: none;
  display: grid;
  gap: 12px;
  margin: 0;
  padding: 0;
}

.page-about .about-points li {
  display: grid;
  grid-template-columns: 2.6em minmax(0, 1fr);
  gap: 10px;
  align-items: baseline;
  padding-bottom: 12px;
  border-bottom: 1px dashed rgba(33, 52, 77, 0.85);
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--paper);
}

.page-about .about-points li:last-child {
  padding-bottom: 0;
  border-bottom: 0;
}

.page-about .about-points__no {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--aqua);
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: clamp(24px, 4vw, 34px) 0 0;
}

/* ---------- 继续阅读 ---------- */
.page-about .about-next {
  margin-top: clamp(44px, 7vw, 78px);
  padding-top: clamp(26px, 4vw, 42px);
  border-top: 1px solid var(--line);
}

.page-about .about-next__grid {
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-next__link {
  position: relative;
  display: block;
  background: var(--navy-800);
  padding: 18px 46px 20px 18px;
  text-decoration: none;
  transition: background 0.3s var(--ease);
}

.page-about .about-next__link:hover,
.page-about .about-next__link:focus-visible {
  background: var(--navy-700);
}

.page-about .about-next__label {
  display: block;
  font-family: var(--font-display);
  font-size: 16px;
  letter-spacing: 0.03em;
  color: var(--paper);
}

.page-about .about-next__desc {
  display: block;
  margin-top: 7px;
  font-size: 13px;
  line-height: 1.65;
  color: var(--mist);
}

.page-about .about-next__arrow {
  position: absolute;
  right: 16px;
  top: 18px;
  font-family: var(--font-mono);
  font-size: 15px;
  color: var(--amber);
  transition: transform 0.3s var(--ease);
}

.page-about .about-next__link:hover .about-next__arrow,
.page-about .about-next__link:focus-visible .about-next__arrow {
  transform: translateX(4px);
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-hero__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

@media (min-width: 760px) {
  .page-about .about-hero__grid {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: clamp(24px, 4vw, 46px);
  }

  .page-about .about-hero__rail {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    padding-top: 6px;
  }

  .page-about .about-hero__rail-cap {
    font-family: var(--font-mono);
    font-size: 11.5px;
    letter-spacing: 0.12em;
    color: var(--amber);
    writing-mode: vertical-rl;
  }

  .page-about .about-hero__rail-cap--now {
    color: var(--mist);
  }

  .page-about .about-hero__rail-line {
    flex: 1;
    width: 1px;
    min-height: 110px;
    background: repeating-linear-gradient(
      180deg,
      var(--aqua) 0 6px,
      transparent 6px 13px
    );
    opacity: 0.55;
  }

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

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

  .page-about .about-hero h1 {
    max-width: 24ch;
  }
}

@media (min-width: 960px) {
  .page-about .about-body {
    display: grid;
    grid-template-columns: 208px minmax(0, 1fr);
    gap: clamp(32px, 5vw, 68px);
    align-items: start;
  }

  .page-about .about-side {
    position: sticky;
    top: 104px;
    margin-bottom: 0;
  }

  .page-about .about-hero__figure {
    margin-top: clamp(34px, 5vw, 56px);
  }
}

@media (min-width: 1040px) {
  .page-about .about-next__grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}