.page-about {
  position: relative;
  padding-top: calc(var(--header-h) + 4px);
  color: var(--ivory);
  background-color: var(--ink);
  background-image:
    radial-gradient(760px 460px at 92% -8%, rgba(40, 44, 99, 0.62), transparent 68%),
    radial-gradient(680px 380px at 0% 10%, rgba(18, 61, 51, 0.85), transparent 70%);
  background-repeat: no-repeat;
}

.page-about::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, rgba(200, 150, 74, 0.07) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(200, 150, 74, 0.07) 1px, transparent 1px);
  background-size: 64px 64px;
  pointer-events: none;
  z-index: 0;
}

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

.page-about h1,
.page-about h2,
.page-about h3 {
  font-family: var(--font-head);
  letter-spacing: -0.02em;
  line-height: 1.24;
  margin: 0;
}

.page-about p {
  margin: 0;
  line-height: 1.75;
  color: var(--mist);
}

.page-about a {
  color: var(--copper-hi);
}

.page-about .mono {
  font-family: var(--font-mono);
  letter-spacing: 0.04em;
}

.page-about .about-crumb {
  padding-top: 18px;
  padding-bottom: 4px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-bottom: 8px;
}

.page-about .about-hero__frame {
  position: relative;
  margin-top: 12px;
  border: 1px solid var(--line-strong);
  background: linear-gradient(155deg, rgba(18, 61, 51, 0.6), rgba(6, 23, 20, 0.94) 64%);
  padding: 26px 18px 30px;
}

.page-about .about-hero__frame::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  height: 8px;
  background: repeating-linear-gradient(90deg, var(--copper) 0 1px, transparent 1px 14px);
  opacity: 0.45;
}

.page-about .about-hero__frame::after {
  content: "";
  position: absolute;
  right: -2px;
  bottom: -2px;
  width: 22px;
  height: 22px;
  border-right: 2px solid var(--neon);
  border-bottom: 2px solid var(--neon);
}

.page-about .about-hero__grid {
  display: grid;
  gap: 26px;
}

.page-about .about-hero__copy h1 {
  font-size: clamp(1.75rem, 6vw, 3.4rem);
  font-weight: 800;
  margin: 14px 0 16px;
  color: var(--ivory);
}

.page-about .about-hero__lead {
  font-size: 1rem;
  color: var(--mist);
  max-width: 58ch;
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

.page-about .about-hero__panel {
  border: 1px solid var(--line);
  background: var(--glass);
  backdrop-filter: blur(10px);
  padding: 18px 16px;
  clip-path: polygon(0 0, calc(100% - 20px) 0, 100% 20px, 100% 100%, 20px 100%, 0 calc(100% - 20px));
}

.page-about .about-hero__panel-kicker {
  font-size: 0.7rem;
  color: var(--copper);
  margin-bottom: 10px;
}

.page-about .about-idx {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-idx li {
  display: grid;
  grid-template-columns: 30px 1fr;
  gap: 2px 10px;
  padding: 12px 0;
  border-bottom: 1px dashed var(--line-soft);
}

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

.page-about .about-idx__no {
  font-size: 0.72rem;
  color: var(--copper);
  padding-top: 3px;
}

.page-about .about-idx__name {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 1rem;
  color: var(--ivory);
}

.page-about .about-idx__desc {
  grid-column: 2;
  font-size: 0.82rem;
  line-height: 1.6;
  color: var(--mist);
}

/* ---------- 通用章节 ---------- */
.page-about .about-sec {
  padding-block: 54px;
}

.page-about .about-head {
  max-width: 46rem;
  margin-bottom: 28px;
}

.page-about .about-head h2 {
  font-size: clamp(1.4rem, 4.6vw, 2.2rem);
  font-weight: 800;
  margin: 12px 0 12px;
  color: var(--ivory);
}

.page-about .about-head--light h2 {
  color: var(--ivory);
}

.page-about .about-lead {
  font-size: 1.02rem;
  color: var(--ivory);
  margin-bottom: 22px;
}

.page-about .about-figure {
  margin: 0;
  border: 1px solid var(--line);
  background: var(--forest);
  overflow: hidden;
}

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

/* ---------- 服务范围 ---------- */
.page-about .about-split {
  display: grid;
  gap: 26px;
}

.page-about .about-split__rail h2 {
  font-size: clamp(1.4rem, 4.6vw, 2.1rem);
  font-weight: 800;
  margin-top: 12px;
  color: var(--ivory);
}

.page-about .about-scope__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line);
}

.page-about .about-scope__list li {
  background: rgba(6, 23, 20, 0.78);
  padding: 18px 16px;
  transition: background var(--ease), transform var(--ease);
}

.page-about .about-scope__list li:hover {
  background: rgba(18, 61, 51, 0.78);
  transform: translateY(-1px);
}

.page-about .about-scope__list h3 {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--copper-hi);
  margin-bottom: 8px;
}

.page-about .about-scope__list p {
  font-size: 0.92rem;
}

/* ---------- 时间轴 ---------- */
.page-about .about-timeline .about-figure {
  margin-bottom: 30px;
}

.page-about .about-tl {
  list-style: none;
  margin: 0;
  padding: 0 0 0 30px;
  position: relative;
}

.page-about .about-tl::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(var(--copper), rgba(200, 150, 74, 0.15));
}

.page-about .about-tl__item {
  position: relative;
  padding-bottom: 28px;
}

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

.page-about .about-tl__item::before {
  content: "";
  position: absolute;
  left: -30px;
  top: 6px;
  width: 11px;
  height: 11px;
  border: 1px solid var(--copper);
  background: var(--ink);
  transform: rotate(45deg);
  transition: background var(--ease), border-color var(--ease);
}

.page-about .about-tl__item:hover::before {
  background: var(--neon);
  border-color: var(--neon);
}

.page-about .about-tl__year {
  font-size: 0.82rem;
  color: var(--copper);
  margin-bottom: 4px;
}

.page-about .about-tl__body h3 {
  font-size: 1.02rem;
  font-weight: 700;
  color: var(--ivory);
  margin-bottom: 6px;
}

.page-about .about-tl__body p {
  font-size: 0.9rem;
  max-width: 62ch;
}

/* ---------- 团队 ---------- */
.page-about .about-team__grid {
  display: grid;
  gap: 24px;
}

.page-about .about-team__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .about-card {
  position: relative;
  border: 1px solid var(--line);
  background: var(--glass);
  backdrop-filter: blur(8px);
  padding: 18px 16px;
  clip-path: polygon(0 0, calc(100% - 16px) 0, 100% 16px, 100% 100%, 0 100%);
  transition: transform var(--ease), border-color var(--ease), background var(--ease);
}

.page-about .about-card:hover,
.page-about .about-card:focus-visible {
  transform: translateY(-2px);
  border-color: var(--line-strong);
  background: linear-gradient(155deg, rgba(18, 61, 51, 0.88), rgba(6, 23, 20, 0.92));
  outline: none;
}

.page-about .about-card:focus-visible {
  box-shadow: 0 0 0 2px var(--neon), 0 0 0 4px var(--ink);
}

.page-about .about-card__no {
  display: inline-block;
  font-size: 0.72rem;
  color: var(--neon);
  margin-bottom: 8px;
}

.page-about .about-card h3 {
  font-size: 1.02rem;
  font-weight: 700;
  color: var(--ivory);
  margin-bottom: 8px;
}

.page-about .about-card p {
  font-size: 0.9rem;
}

/* ---------- 审核 ---------- */
.page-about .about-audit {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(11, 43, 36, 0.6), rgba(6, 23, 20, 0.9));
}

.page-about .about-audit__grid {
  display: grid;
  gap: 28px;
}

.page-about .about-audit__intro h2 {
  font-size: clamp(1.4rem, 4.6vw, 2.1rem);
  font-weight: 800;
  margin: 12px 0 12px;
  color: var(--ivory);
}

.page-about .about-audit__figure {
  margin-top: 22px;
}

.page-about .about-audit__steps {
  display: grid;
  gap: 12px;
  align-content: start;
}

.page-about .about-audit__steps details {
  border: 1px solid var(--line);
  background: rgba(18, 61, 51, 0.4);
  padding: 14px 16px;
  transition: border-color var(--ease), background var(--ease);
}

.page-about .about-audit__steps details[open] {
  border-color: var(--line-strong);
  background: rgba(18, 61, 51, 0.66);
}

.page-about .about-audit__steps summary {
  display: flex;
  align-items: center;
  gap: 12px;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 1rem;
  color: var(--ivory);
  min-height: 32px;
}

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

.page-about .about-audit__steps summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  color: var(--copper);
  font-size: 1.1rem;
}

.page-about .about-audit__steps details[open] summary::after {
  content: "−";
  color: var(--neon);
}

.page-about .about-audit__steps summary span {
  font-size: 0.72rem;
  color: var(--copper);
  font-weight: 400;
}

.page-about .about-audit__steps details p {
  margin-top: 10px;
  font-size: 0.9rem;
}

.page-about .about-audit__note {
  font-size: 0.86rem;
  line-height: 1.7;
  color: var(--mist);
  border-left: 2px solid var(--copper);
  padding-left: 14px;
}

/* ---------- 会员 ---------- */
.page-about .about-member {
  background: linear-gradient(158deg, rgba(40, 44, 99, 0.94), rgba(11, 43, 36, 0.92) 72%);
  border-bottom: 1px solid var(--line);
}

.page-about .about-tiers {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .about-tiers li {
  border: 1px solid rgba(200, 150, 74, 0.34);
  background: linear-gradient(160deg, rgba(11, 43, 36, 0.72), rgba(6, 23, 20, 0.86));
  padding: 18px 16px;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 18px), calc(100% - 18px) 100%, 0 100%);
  transition: border-color var(--ease), transform var(--ease);
}

.page-about .about-tiers li:hover {
  border-color: var(--copper-hi);
  transform: translateY(-2px);
}

.page-about .about-tiers__no {
  font-size: 0.7rem;
  color: var(--copper);
  margin-bottom: 10px;
}

.page-about .about-tiers h3 {
  font-size: 1.08rem;
  font-weight: 700;
  color: var(--ivory);
  margin-bottom: 8px;
}

.page-about .about-tiers p {
  font-size: 0.9rem;
}

.page-about .about-member__more {
  margin-top: 24px;
  font-size: 0.94rem;
  max-width: 60ch;
}

.page-about .about-member__more a {
  border-bottom: 1px solid var(--copper);
  text-decoration: none;
  padding-bottom: 1px;
}

.page-about .about-member__more a:hover {
  border-bottom-color: var(--neon);
  color: var(--neon);
}

/* ---------- 覆盖与节奏 ---------- */
.page-about .about-response {
  background: linear-gradient(152deg, rgba(91, 35, 56, 0.86), rgba(6, 23, 20, 0.94) 74%);
}

.page-about .about-stats {
  display: grid;
  gap: 1px;
  margin: 0;
  background: rgba(200, 150, 74, 0.24);
  border: 1px solid var(--line);
}

.page-about .about-stats__cell {
  background: rgba(6, 23, 20, 0.82);
  padding: 18px 16px;
}

.page-about .about-stats dt {
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  color: var(--mist);
}

.page-about .about-stats dd {
  margin: 8px 0 8px;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 1rem;
  color: var(--copper-hi);
}

.page-about .about-stats__num {
  font-size: 1.6rem;
  color: var(--ivory);
  margin-right: 2px;
}

.page-about .about-stats__time {
  font-size: 1.15rem;
}

.page-about .about-stats p {
  font-size: 0.84rem;
  line-height: 1.65;
}

/* ---------- 选择理由与收尾 ---------- */
.page-about .about-why__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 16px;
}

.page-about .about-why__list li {
  position: relative;
  border-top: 2px solid var(--copper);
  background: linear-gradient(180deg, rgba(18, 61, 51, 0.5), rgba(6, 23, 20, 0.7));
  padding: 20px 16px 22px;
}

.page-about .about-why__list h3 {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--ivory);
  margin-bottom: 10px;
}

.page-about .about-why__list p {
  font-size: 0.92rem;
}

.page-about .about-cta {
  margin-top: 34px;
  display: grid;
  gap: 20px;
  border: 1px solid var(--line-strong);
  background:
    repeating-linear-gradient(135deg, rgba(200, 150, 74, 0.06) 0 2px, transparent 2px 16px),
    linear-gradient(150deg, rgba(18, 61, 51, 0.9), rgba(6, 23, 20, 0.94));
  padding: 24px 18px;
}

.page-about .about-cta h2 {
  font-size: clamp(1.25rem, 4vw, 1.7rem);
  font-weight: 800;
  color: var(--ivory);
  margin-bottom: 10px;
}

.page-about .about-cta p {
  font-size: 0.92rem;
  max-width: 52ch;
}

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

@media (min-width: 640px) {
  .page-about .about-stats {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

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

  .page-about .about-cta {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    padding: 28px 26px;
  }
}

@media (min-width: 900px) {
  .page-about {
    padding-top: calc(var(--header-h) + 10px);
  }

  .page-about .about-sec {
    padding-block: 84px;
  }

  .page-about .about-hero__frame {
    padding: 46px 44px 48px;
    margin-top: 18px;
  }

  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 52px;
    align-items: start;
  }

  .page-about .about-hero__panel {
    padding: 22px 22px;
  }

  .page-about .about-split {
    grid-template-columns: minmax(0, 4fr) minmax(0, 8fr);
    gap: 56px;
    align-items: start;
  }

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

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

  .page-about .about-timeline .about-figure {
    margin-bottom: 40px;
  }

  .page-about .about-tl {
    padding-left: 140px;
  }

  .page-about .about-tl::before {
    left: 112px;
  }

  .page-about .about-tl__item::before {
    left: -34px;
    top: 8px;
  }

  .page-about .about-tl__item {
    padding-bottom: 34px;
  }

  .page-about .about-tl__year {
    position: absolute;
    left: -140px;
    top: 2px;
    width: 90px;
    text-align: right;
    font-size: 0.9rem;
  }

  .page-about .about-team__grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: 32px;
    align-items: start;
  }

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

  .page-about .about-audit__grid {
    grid-template-columns: minmax(0, 6fr) minmax(0, 6fr);
    gap: 48px;
    align-items: start;
  }

  .page-about .about-tiers {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 16px;
  }

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

  .page-about .about-why__list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 20px;
  }

  .page-about .about-head {
    margin-bottom: 36px;
  }
}