.page-about {
  --about-cut: 14px;
  --about-cut-lg: 26px;
  --about-pad: 20px;
  background: var(--field);
  color: var(--paper);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.78;
  padding-bottom: 64px;
}

.page-about h1,
.page-about h2,
.page-about h3 {
  font-family: var(--font-title);
  font-weight: 800;
  line-height: 1.14;
  letter-spacing: 0.01em;
  margin: 0 0 14px;
  text-wrap: balance;
}

.page-about h2 {
  font-size: clamp(26px, 5.2vw, 38px);
}

.page-about h3 {
  font-size: clamp(18px, 3.4vw, 23px);
  margin-bottom: 8px;
}

.page-about p {
  margin: 0 0 14px;
  color: var(--mist);
}

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

.page-about .eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 12px;
}

.about-tick {
  display: inline-block;
  width: 20px;
  height: 2px;
  background: var(--gold);
}

.page-about .mono {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
}

.about-link {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(47, 227, 198, 0.4);
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

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

.about-serif {
  font-family: var(--font-serif);
  font-size: clamp(20px, 4vw, 26px);
  line-height: 1.5;
  color: var(--gold-soft) !important;
  margin: 0;
}

.about-cap {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--mist-dim);
  letter-spacing: 0.02em;
}

/* ---------- 面包屑 ---------- */
.about-crumb {
  padding-top: 18px;
}

/* ---------- 首屏 ---------- */
.about-hero {
  position: relative;
  padding: 14px 0 52px;
  background:
    radial-gradient(115% 85% at 102% -10%, rgba(217, 169, 63, 0.13), transparent 58%),
    radial-gradient(90% 70% at -10% 110%, rgba(15, 143, 128, 0.14), transparent 60%);
}

.about-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 30px;
}

.about-hero__lead h1 {
  font-size: clamp(30px, 7.6vw, 56px);
  line-height: 1.08;
  margin-bottom: 18px;
}

.about-hero__intro {
  font-size: 16px;
  max-width: 58ch;
}

.about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 22px;
}

.about-hero__board {
  position: relative;
  background: var(--panel);
  padding: 22px var(--about-pad) 16px;
  clip-path: polygon(
    0 0,
    calc(100% - var(--about-cut-lg)) 0,
    100% var(--about-cut-lg),
    100% 100%,
    var(--about-cut-lg) 100%,
    0 calc(100% - var(--about-cut-lg))
  );
}

.about-hero__board::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 74px;
  height: 3px;
  background: var(--gold);
}

.board__title {
  font-family: var(--font-title);
  font-weight: 700;
  font-size: 13px;
  letter-spacing: 0.22em;
  color: var(--gold);
  margin: 0 0 8px !important;
}

.board__row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding: 11px 0;
  border-bottom: 1px dashed var(--line);
}

.board__row:last-child {
  border-bottom: 0;
}

.board__k {
  font-size: 13.5px;
  letter-spacing: 0.06em;
  color: var(--mist-dim);
  margin: 0 !important;
  flex: 0 0 auto;
}

.board__v {
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 15px;
  color: var(--gold-soft);
  text-align: right;
  margin: 0 !important;
  line-height: 1.4;
}

.board__v small {
  display: block;
  font-size: 11.5px;
  font-weight: 400;
  color: var(--mist-dim);
  letter-spacing: 0.02em;
  margin-top: 3px;
}

/* ---------- 章节骨架 ---------- */
.about-section {
  padding: 46px 0;
  border-top: 1px solid var(--line);
}

.about-lede {
  max-width: 62ch;
  font-size: 16.5px;
  margin-bottom: 24px;
}

/* ---------- 起点与主张 ---------- */
.about-origin__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 22px;
}

.about-origin__aside {
  border-left: 2px solid var(--gold);
  padding-left: 16px;
}

.about-origin__body p {
  max-width: 66ch;
}

.about-facts {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  gap: 2px;
  background: var(--line);
  clip-path: polygon(
    0 0,
    calc(100% - var(--about-cut-lg)) 0,
    100% var(--about-cut-lg),
    100% 100%,
    var(--about-cut-lg) 100%,
    0 calc(100% - var(--about-cut-lg))
  );
}

.about-facts li {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 8px;
  padding: 13px 16px;
  background: var(--panel);
  font-size: 14.5px;
  color: var(--mist);
  line-height: 1.6;
}

.about-facts strong {
  color: var(--paper);
  font-weight: 700;
  letter-spacing: 0.04em;
  font-size: 14px;
}

.about-facts__mark {
  width: 6px;
  height: 6px;
  flex: 0 0 auto;
  background: var(--gold);
  transform: rotate(45deg) translateY(-2px);
}

/* ---------- 战术板连线 ---------- */
.about-svgline {
  display: block;
  width: 100%;
  height: 42px;
  color: var(--line);
  margin: 4px 0 -18px;
}

/* ---------- 方法 ---------- */
.about-method__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 28px;
}

.about-method__figure {
  margin: 0;
}

.about-method__body p {
  max-width: 66ch;
}

.steps {
  list-style: none;
  margin: 26px 0 22px;
  padding: 0;
  display: grid;
  gap: 14px;
}

.steps__item {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  gap: 14px;
  align-items: start;
  background: var(--panel);
  border-left: 3px solid var(--gold);
  padding: 16px 16px 14px;
}

.steps__num {
  font-size: 20px;
  font-weight: 600;
  color: var(--gold);
  line-height: 1.3;
  letter-spacing: 0.04em;
}

.steps__text h3 {
  font-size: 18px;
  margin-bottom: 6px;
}

.steps__text p {
  font-size: 14.8px;
  line-height: 1.72;
  margin: 0;
}

/* ---------- 团队 ---------- */
.about-crew__head {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 24px;
  margin-bottom: 28px;
}

.about-crew__figure {
  margin: 0;
}

.about-crew__intro p {
  max-width: 60ch;
}

.crew {
  display: grid;
  gap: 2px;
  background: var(--line);
}

.crew__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 6px;
  background: var(--panel);
  padding: 16px 18px;
}

.crew__name {
  display: flex;
  align-items: baseline;
  gap: 10px;
  margin: 0 !important;
  font-family: var(--font-title);
  font-weight: 700;
  font-size: 17px;
  color: var(--paper);
  letter-spacing: 0.03em;
}

.crew__count {
  font-size: 24px;
  font-weight: 600;
  color: var(--gold);
  line-height: 1;
}

.crew__desc {
  margin: 0 !important;
  font-size: 14.6px;
  line-height: 1.72;
  color: var(--mist);
}

.crew__row--total {
  background: linear-gradient(90deg, rgba(217, 169, 63, 0.16), rgba(16, 42, 35, 0.9) 60%);
}

.crew__row--total .crew__count {
  color: var(--cyan);
}

/* ---------- 运营阶段 ---------- */
.about-stage__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 28px;
}

.railway {
  list-style: none;
  margin: 26px 0 0;
  padding: 0 0 0 22px;
  position: relative;
  display: grid;
  gap: 26px;
}

.railway::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 6px;
  bottom: 6px;
  width: 1px;
  background: linear-gradient(180deg, var(--gold), var(--line) 55%, var(--line));
}

.railway__item {
  position: relative;
}

.railway__dot {
  position: absolute;
  left: -22px;
  top: 7px;
  width: 11px;
  height: 11px;
  background: var(--field);
  border: 2px solid var(--gold);
  transform: rotate(45deg);
}

.railway__item--now .railway__dot {
  background: var(--cyan);
  border-color: var(--cyan);
  box-shadow: 0 0 0 4px rgba(47, 227, 198, 0.16);
}

.railway__label {
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--mist-dim);
  margin: 0 0 4px !important;
}

.railway__item--now .railway__label {
  color: var(--cyan);
}

.railway__item h3 {
  font-size: clamp(18px, 3.6vw, 22px);
  margin-bottom: 6px;
}

.railway__item p:not(.railway__label) {
  font-size: 15px;
  line-height: 1.75;
  max-width: 58ch;
  margin: 0;
}

.about-stage__figure {
  margin: 0;
}

/* ---------- 合作生态 ---------- */
.eco {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
}

.eco__card {
  background: var(--panel);
  padding: 22px 20px 20px;
  position: relative;
  clip-path: polygon(
    0 0,
    calc(100% - var(--about-cut)) 0,
    100% var(--about-cut),
    100% 100%,
    var(--about-cut) 100%,
    0 calc(100% - var(--about-cut))
  );
}

.eco__card::after {
  content: "";
  position: absolute;
  left: 20px;
  right: 20px;
  bottom: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--gold), transparent);
}

.eco__num {
  font-size: 40px;
  font-weight: 600;
  line-height: 1;
  color: var(--gold);
  margin: 0 0 10px !important;
}

.eco__card h3 {
  font-size: 19px;
  margin-bottom: 8px;
}

.eco__card p {
  font-size: 14.6px;
  line-height: 1.72;
}

.eco__gain {
  margin-top: 12px !important;
  padding-top: 12px;
  border-top: 1px dashed var(--line);
  color: var(--teal) !important;
  font-size: 13.8px;
  line-height: 1.65;
}

/* ---------- 合作方式 ---------- */
.about-work__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 26px;
}

.about-work__intro p {
  max-width: 56ch;
}

.about-work__intro .btn {
  margin-top: 8px;
}

.about-work__list {
  display: grid;
  gap: 10px;
  align-content: start;
}

.fold {
  background: var(--panel);
  border-left: 3px solid var(--line);
  transition: border-color var(--dur) var(--ease);
}

.fold[open] {
  border-left-color: var(--cyan);
}

.fold__sum {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 15px 16px;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-title);
  font-weight: 700;
  font-size: 16.5px;
  color: var(--paper);
  letter-spacing: 0.02em;
  transition: background var(--dur) var(--ease);
}

.fold__sum::-webkit-details-marker {
  display: none;
}

.fold__sum:hover,
.fold__sum:focus-visible {
  background: rgba(47, 227, 198, 0.07);
}

.fold__key {
  flex: 0 0 auto;
  width: 26px;
  height: 26px;
  display: grid;
  place-items: center;
  font-size: 13px;
  color: var(--field);
  background: var(--gold);
  clip-path: polygon(0 0, 100% 0, 100% 70%, 70% 100%, 0 100%);
}

.fold[open] .fold__key {
  background: var(--cyan);
}

.fold__title {
  flex: 1 1 auto;
  min-width: 0;
}

.fold__body {
  padding: 2px 16px 18px 54px;
}

.fold__steps {
  margin: 0 0 10px;
  padding-left: 18px;
  display: grid;
  gap: 7px;
}

.fold__steps li {
  font-size: 14.4px;
  line-height: 1.72;
  color: var(--mist);
}

.fold__body p {
  font-size: 13.5px;
  color: var(--mist-dim);
  margin: 0;
}

/* ---------- 结尾 ---------- */
.about-cta {
  margin-top: 40px;
  background: linear-gradient(115deg, rgba(217, 169, 63, 0.16), rgba(8, 23, 19, 0.2) 55%, rgba(15, 143, 128, 0.18));
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  padding: 40px 0;
}

.about-cta__inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 20px;
  align-items: center;
}

.about-cta__text h2 {
  font-size: clamp(22px, 4.6vw, 30px);
  margin-bottom: 8px;
}

.about-cta__text p {
  max-width: 52ch;
  font-size: 15px;
  margin: 0;
}

.about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* ---------- 断点 ---------- */
@media (min-width: 760px) {
  .page-about {
    --about-pad: 26px;
  }

  .about-hero {
    padding: 24px 0 64px;
  }

  .about-section {
    padding: 60px 0;
  }

  .crew__row {
    grid-template-columns: 210px minmax(0, 1fr);
    gap: 22px;
    align-items: baseline;
    padding: 18px 22px;
  }

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

  .fold__body {
    padding: 4px 22px 20px 58px;
  }

  .about-cta__inner {
    grid-template-columns: minmax(0, 1.15fr) auto;
    gap: 28px;
  }
}

@media (min-width: 900px) {
  .about-hero__grid {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 0.85fr);
    gap: 46px;
    align-items: start;
  }

  .about-hero__board {
    padding: 26px 26px 18px;
  }

  .about-origin__grid {
    grid-template-columns: 250px minmax(0, 1fr);
    gap: 40px;
  }

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

  .about-method__grid {
    grid-template-columns: minmax(0, 0.92fr) minmax(0, 1.08fr);
    gap: 42px;
    align-items: start;
  }

  .about-crew__head {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.85fr);
    gap: 40px;
    align-items: center;
    margin-bottom: 32px;
  }

  .about-stage__grid {
    grid-template-columns: minmax(0, 1.25fr) minmax(0, 0.75fr);
    gap: 44px;
    align-items: start;
  }

  .about-stage__figure {
    position: sticky;
    top: calc(var(--masthead-h) + 20px);
  }

  .eco {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 16px;
  }

  .about-work__grid {
    grid-template-columns: minmax(0, 0.82fr) minmax(0, 1.18fr);
    gap: 44px;
    align-items: start;
  }
}

@media (min-width: 1180px) {
  .page-about {
    font-size: 17px;
    padding-bottom: 88px;
  }

  .about-hero__lead h1 {
    font-size: 58px;
  }

  .about-serif {
    font-size: 27px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .fold,
  .fold__sum,
  .about-link {
    transition: none;
  }
}