.page-about {
  --about-rail: 210px;
  --about-line: var(--grid);
  background: var(--paper);
  color: var(--ink);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: calc(var(--header-h) + 44px) 0 clamp(40px, 6vw, 76px);
  background: linear-gradient(180deg, var(--paper) 0%, var(--paper) 58%, var(--cream) 100%);
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, var(--grid-line) 1px, transparent 1px),
    linear-gradient(to bottom, var(--grid-line) 1px, transparent 1px);
  background-size: 48px 48px;
  -webkit-mask-image: radial-gradient(ellipse at 18% 0%, #000 0%, transparent 72%);
  mask-image: radial-gradient(ellipse at 18% 0%, #000 0%, transparent 72%);
  pointer-events: none;
}

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

.page-about .about-hero__kicker {
  margin: 28px 0 0;
  color: var(--orange);
}

.page-about .about-hero h1 {
  margin: 14px 0 0;
  max-width: 13em;
  font-size: clamp(30px, 5.4vw, 58px);
  line-height: 1.14;
  letter-spacing: -0.02em;
  font-weight: 900;
  color: var(--blue);
}

.page-about .about-hero__lede {
  margin: 24px 0 0;
  max-width: 44em;
  font-size: clamp(15px, 0.5vw + 13px, 17px);
  line-height: 1.85;
  color: var(--ink);
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(170px, 1fr));
  gap: 1px;
  margin: clamp(32px, 5vw, 56px) 0 0;
  padding: 0;
  background: var(--grid);
  border: 1px solid var(--grid);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .about-stat {
  margin: 0;
  padding: 18px 20px 20px;
  background: var(--paper);
}

.page-about .about-stat__k {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--gray);
  text-transform: uppercase;
}

.page-about .about-stat__v {
  margin: 10px 0 0;
  font-family: var(--font-mono);
  font-size: clamp(21px, 1.4vw + 16px, 30px);
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--blue);
  line-height: 1.15;
}

.page-about .about-stat__v--text {
  font-size: clamp(16px, 0.8vw + 13px, 20px);
  font-weight: 500;
}

.page-about .about-stat__unit {
  margin-left: 4px;
  font-size: 0.55em;
  font-weight: 500;
  color: var(--gray);
}

/* ---------- 通用区块 ---------- */
.page-about .section {
  padding: clamp(56px, 7.5vw, 110px) 0;
}

.page-about .section-head h2 {
  margin: 12px 0 0;
  font-size: clamp(24px, 3.2vw, 40px);
  line-height: 1.2;
  letter-spacing: -0.02em;
  font-weight: 900;
  color: var(--blue);
}

.page-about .about-section-lede {
  margin: 16px 0 0;
  max-width: 46em;
  font-size: 16px;
  line-height: 1.85;
  color: var(--gray);
}

.page-about .section-head .label {
  color: var(--orange);
}

/* ---------- 左右分栏 ---------- */
.page-about .about-row {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(20px, 3vw, 40px);
}

.page-about .about-rail__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--orange);
  margin-bottom: 12px;
}

.page-about .about-rail__title {
  margin: 0;
  padding-top: 14px;
  border-top: 2px solid var(--blue);
  font-size: clamp(19px, 1.4vw + 14px, 25px);
  line-height: 1.35;
  letter-spacing: -0.01em;
  font-weight: 900;
  color: var(--blue);
}

.page-about .about-body p {
  margin: 0 0 1.1em;
  max-width: 46em;
  line-height: 1.85;
  color: var(--ink);
}

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

.page-about .about-body__lead {
  border-left: 4px solid var(--orange);
  padding-left: 16px;
  font-size: clamp(16px, 0.6vw + 14px, 19px);
  line-height: 1.72;
  font-weight: 500;
  color: var(--blue);
}

.page-about .about-body strong {
  font-family: var(--font-mono);
  font-size: 1.08em;
  font-weight: 700;
  color: var(--orange);
}

/* ---------- 首屏下方配图 ---------- */
.page-about .about-map {
  margin: clamp(36px, 5vw, 64px) 0 0;
}

.page-about .figure__img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
}

/* ---------- 阶段演进 ---------- */
.page-about .about-stages-section {
  background: var(--cream);
  border-top: 1px solid var(--grid);
  border-bottom: 1px solid var(--grid);
}

.page-about .about-stages {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(28px, 4vw, 48px);
  margin-top: clamp(30px, 4.5vw, 56px);
}

.page-about .about-timeline__label {
  margin: 0;
  color: var(--gray);
}

.page-about .about-timeline__list {
  list-style: none;
  margin: 14px 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .about-timeline__link {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 8px 15px;
  border: 1px solid var(--grid);
  border-radius: 999px;
  background: var(--paper);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--gray);
  text-decoration: none;
  transition: border-color 200ms var(--ease), color 200ms var(--ease);
}

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

.page-about .about-timeline__dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  border: 2px solid var(--grid);
  background: transparent;
  transition: border-color 200ms var(--ease), background-color 200ms var(--ease);
}

.page-about .about-timeline__link:hover .about-timeline__dot,
.page-about .about-timeline__link:focus-visible .about-timeline__dot {
  border-color: var(--orange);
  background: var(--orange);
}

.page-about .about-stage-list {
  display: grid;
  gap: clamp(24px, 3vw, 42px);
}

.page-about .stage {
  padding: 2px 0 2px clamp(18px, 2.4vw, 30px);
  border-left: 3px solid var(--grid);
  scroll-margin-top: calc(var(--header-h) + 24px);
  transition: border-left-color 220ms var(--ease);
}

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

.page-about .stage__head {
  display: flex;
  align-items: baseline;
  gap: 14px;
  margin-bottom: 12px;
}

.page-about .stage__idx {
  flex: none;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--orange);
}

.page-about .stage__title {
  margin: 0;
  font-size: clamp(19px, 1.3vw + 14px, 25px);
  line-height: 1.4;
  letter-spacing: -0.01em;
  font-weight: 900;
  color: var(--blue);
}

.page-about .stage p {
  margin: 0 0 0.85em;
  max-width: 48em;
  line-height: 1.85;
  color: var(--ink);
}

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

/* ---------- 收录标准 ---------- */
.page-about .about-fields {
  margin-top: clamp(28px, 4vw, 48px);
}

.page-about .about-field {
  transition: border-color 220ms var(--ease);
}

.page-about .about-field:hover {
  border-color: var(--orange);
}

.page-about .about-field__k {
  display: block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--orange);
  margin-bottom: 10px;
}

.page-about .about-field__t {
  margin: 0 0 10px;
  font-size: 17px;
  line-height: 1.4;
  font-weight: 700;
  color: var(--blue);
}

.page-about .about-field p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--gray);
}

.page-about .about-method__note {
  margin: clamp(28px, 4vw, 44px) 0 0;
  max-width: 62em;
  padding: 20px 24px;
  background: var(--blue-light);
  border-radius: var(--radius);
  font-size: 15px;
  line-height: 1.8;
  color: var(--blue);
}

/* ---------- 服务网络 ---------- */
.page-about .about-net {
  position: relative;
  background: var(--blue);
  color: var(--paper);
  overflow: hidden;
}

.page-about .about-net::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, rgba(253, 251, 247, 0.07) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(253, 251, 247, 0.07) 1px, transparent 1px);
  background-size: 56px 56px;
  pointer-events: none;
}

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

.page-about .about-net .section-head h2 {
  color: var(--paper);
}

.page-about .about-net .about-section-lede {
  color: rgba(253, 251, 247, 0.78);
}

.page-about .about-net .label {
  color: var(--orange);
}

.page-about .about-net__figure {
  margin: clamp(30px, 4vw, 52px) 0 0;
}

.page-about .about-net .figure__cap {
  color: rgba(253, 251, 247, 0.68);
}

.page-about .about-net__list {
  list-style: none;
  margin: clamp(28px, 4vw, 48px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(185px, 1fr));
  gap: 14px;
}

.page-about .about-net__item {
  padding: 18px 20px;
  border: 1px solid rgba(253, 251, 247, 0.18);
  border-radius: var(--radius);
  background: var(--blue-deep);
  transition: border-color 220ms var(--ease);
}

.page-about .about-net__item:hover {
  border-color: var(--orange);
}

.page-about .about-net__name {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--orange);
  margin-bottom: 9px;
}

.page-about .about-net__desc {
  display: block;
  font-size: 14px;
  line-height: 1.7;
  color: rgba(253, 251, 247, 0.82);
}

/* ---------- 合作与认可 ---------- */
.page-about .about-partners {
  margin-top: clamp(28px, 4vw, 46px);
}

.page-about .about-partner {
  padding: clamp(22px, 2.6vw, 30px);
  border: 1px solid var(--grid);
  border-radius: var(--radius);
  background: var(--paper);
  transition: border-color 220ms var(--ease);
}

.page-about .about-partner:hover {
  border-color: var(--orange);
}

.page-about .about-partner__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(26px, 2.2vw + 18px, 38px);
  line-height: 1;
  font-weight: 700;
  color: var(--orange);
  letter-spacing: -0.01em;
}

.page-about .about-partner__unit {
  margin-left: 4px;
  font-size: 0.42em;
  font-weight: 500;
  color: var(--gray);
}

.page-about .about-partner__t {
  margin: 14px 0 8px;
  font-size: 17px;
  line-height: 1.4;
  font-weight: 700;
  color: var(--blue);
}

.page-about .about-partner p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--gray);
}

.page-about .about-partners__note {
  margin: clamp(24px, 3vw, 36px) 0 0;
  max-width: 60em;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink);
}

.page-about .about-partners__note a {
  color: var(--blue);
  text-decoration: underline;
  text-underline-offset: 4px;
  transition: color 200ms var(--ease);
}

.page-about .about-partners__note a:hover {
  color: var(--orange);
}

/* ---------- 下一步 ---------- */
.page-about .about-next {
  background: var(--cream);
  border-top: 1px solid var(--grid);
}

.page-about .about-next__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(30px, 4vw, 56px);
}

.page-about .about-next__lead h2 {
  margin: 12px 0 0;
  font-size: clamp(24px, 3.2vw, 40px);
  line-height: 1.2;
  letter-spacing: -0.02em;
  font-weight: 900;
  color: var(--blue);
}

.page-about .about-next__lead p {
  margin: 18px 0 0;
  max-width: 42em;
  line-height: 1.85;
  color: var(--ink);
}

.page-about .about-next__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(24px, 3vw, 34px);
}

.page-about .about-next__list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--grid);
}

.page-about .about-next__list li {
  position: relative;
  padding: 16px 0 16px 26px;
  border-bottom: 1px solid var(--grid);
  font-size: 15px;
  line-height: 1.78;
  color: var(--ink);
}

.page-about .about-next__list li::before {
  content: "";
  position: absolute;
  left: 3px;
  top: 27px;
  width: 11px;
  height: 2px;
  background: var(--orange);
}

/* ---------- 响应式 ---------- */
@media (min-width: 860px) {
  .page-about .about-row {
    grid-template-columns: var(--about-rail) 1fr;
    gap: clamp(28px, 5vw, 80px);
    align-items: start;
  }

  .page-about .about-row--reverse > .about-rail {
    order: 2;
  }

  .page-about .about-row--reverse > .about-body {
    order: 1;
  }
}

@media (min-width: 940px) {
  .page-about .about-stages {
    grid-template-columns: 200px 1fr;
    gap: clamp(40px, 6vw, 92px);
    align-items: start;
  }

  .page-about .about-timeline {
    position: sticky;
    top: calc(var(--header-h) + 36px);
  }

  .page-about .about-timeline__list {
    flex-direction: column;
    flex-wrap: nowrap;
    gap: 0;
    position: relative;
    padding-left: 0;
  }

  .page-about .about-timeline__list::before {
    content: "";
    position: absolute;
    left: 7px;
    top: 14px;
    bottom: 14px;
    width: 2px;
    background-image: repeating-linear-gradient(
      to bottom,
      var(--grid) 0 6px,
      transparent 6px 12px
    );
  }

  .page-about .about-timeline__link {
    display: grid;
    grid-template-columns: 16px auto 1fr;
    align-items: center;
    gap: 12px;
    width: 100%;
    padding: 11px 0;
    border: 0;
    border-radius: 0;
    background: transparent;
  }

  .page-about .about-timeline__dot {
    position: relative;
    z-index: 1;
    width: 16px;
    height: 16px;
    background: var(--cream);
  }

  .page-about .about-timeline__link:hover .about-timeline__dot,
  .page-about .about-timeline__link:focus-visible .about-timeline__dot {
    background: var(--orange);
  }

  .page-about .about-timeline__node {
    color: var(--gray);
  }

  .page-about .about-timeline__name {
    font-family: var(--font-sans);
    font-size: 14px;
    letter-spacing: 0;
    color: var(--blue);
  }
}

@media (min-width: 900px) {
  .page-about .about-next__grid {
    grid-template-columns: 1fr 1fr;
    align-items: start;
  }
}