.page-about {
  --about-section-gap: clamp(3.5rem, 9vw, 8rem);
  --about-band-gap: clamp(1.5rem, 4vw, 3.25rem);
  --about-num: #C9A227;
  padding-bottom: clamp(3rem, 8vw, 7rem);
}

/* ---------- 首屏 ---------- */

.page-about__head {
  padding-block: clamp(2rem, 5vw, 3.75rem) clamp(1.5rem, 4vw, 2.5rem);
}

.page-about .section-label {
  position: relative;
  margin: 0;
  padding-left: 1.15rem;
  font-size: var(--step-12);
  letter-spacing: 0.2em;
  color: var(--gold);
  font-family: var(--font-latin), var(--font-cjk);
}

.page-about .section-label::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.55em;
  width: 0.6rem;
  height: 1px;
  background: var(--gold);
}

.page-about__title {
  margin: clamp(0.9rem, 2.5vw, 1.6rem) 0 0;
  font-family: var(--font-cjk);
  font-weight: 300;
  font-size: clamp(2.15rem, 8.2vw, 5rem);
  line-height: 1.06;
  letter-spacing: -0.03em;
  color: var(--cloud);
}

.page-about__head-grid {
  display: grid;
  gap: clamp(1.5rem, 4vw, 2.75rem);
  margin-top: clamp(1.5rem, 4vw, 2.5rem);
  padding-top: clamp(1.25rem, 3vw, 2rem);
  border-top: 1px solid var(--line);
}

@media (min-width: 900px) {
  .page-about__head-grid {
    grid-template-columns: minmax(0, 6fr) minmax(0, 4fr);
    align-items: start;
  }
}

.page-about__lede {
  margin: 0;
  max-width: 34em;
  font-size: var(--step-17);
  line-height: 1.8;
  color: var(--cloud);
}

.page-about__stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
  margin: 0;
}

.page-about__stat dt {
  font-size: var(--step-12);
  letter-spacing: 0.08em;
  color: var(--mist);
  line-height: 1.5;
}

.page-about__stat dd {
  margin: 0.4rem 0 0;
  font-size: clamp(1.35rem, 4.5vw, 2rem);
  font-weight: 700;
  line-height: 1;
  color: var(--gold);
  font-variant-numeric: tabular-nums;
}

.page-about__unit {
  margin-left: 0.15rem;
  font-size: 0.72em;
  font-weight: 400;
  color: var(--mist);
}

/* ---------- 通用双栏带 ---------- */

.page-about__section {
  margin-block: var(--about-section-gap);
}

.page-about__band {
  display: grid;
  gap: var(--about-band-gap);
  align-items: start;
}

@media (min-width: 900px) {
  .page-about__band {
    grid-template-columns: minmax(0, 4fr) minmax(0, 8fr);
  }
  .page-about__band--alt {
    grid-template-columns: minmax(0, 5.5fr) minmax(0, 6.5fr);
  }
}

.page-about__rail .heading {
  margin: 0.85rem 0 0;
  font-family: var(--font-cjk);
  font-weight: 900;
  font-size: clamp(1.5rem, 4.4vw, 2.25rem);
  line-height: 1.18;
  letter-spacing: -0.02em;
  color: var(--cloud);
}

.page-about__rail .prose {
  margin: 1rem 0 0;
}

.page-about__body .prose {
  margin: 1.5rem 0 0;
  max-width: 42em;
}

/* ---------- 团队构成 ---------- */

.page-about__teams {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1rem;
}

.team-row {
  display: grid;
  grid-template-columns: 3.25rem minmax(0, 1fr);
  gap: 1rem;
  padding: 1.15rem 1.15rem 1.3rem;
  background: var(--ink-1);
  border: 2px solid var(--line);
  border-left-width: 4px;
  border-left-color: var(--gold);
}

.team-row--eng {
  border-left-color: var(--teal-deep);
}

.team-row--sup {
  border-left-color: var(--copper);
}

.team-row__num {
  font-family: var(--font-latin), var(--font-cjk);
  font-size: clamp(1.6rem, 5vw, 2rem);
  font-weight: 700;
  line-height: 1;
  color: var(--gold);
  font-variant-numeric: tabular-nums;
}

.team-row--eng .team-row__num {
  color: var(--teal-deep);
}

.team-row--sup .team-row__num {
  color: var(--copper);
}

.team-row__name {
  margin: 0;
  font-size: var(--step-17);
  font-weight: 900;
  letter-spacing: -0.01em;
  color: var(--cloud);
}

.team-row__text p {
  margin: 0.5rem 0 0;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--mist);
}

.page-about__figure {
  margin: clamp(1.5rem, 3.5vw, 2.25rem) 0 0;
}

.page-about__figure img,
.page-about__wide img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--line);
}

/* ---------- 六道工序 ---------- */

.page-about__wide {
  margin: 0 0 clamp(1.75rem, 4vw, 2.75rem);
}

.page-about__wide--end {
  margin-block: clamp(1.75rem, 4vw, 2.75rem) 0;
}

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

.step {
  position: relative;
  padding-left: 2.85rem;
  padding-bottom: 1.9rem;
}

.step:last-child {
  padding-bottom: 0;
}

.step::before {
  content: "";
  position: absolute;
  left: 0.6rem;
  top: 1.5rem;
  bottom: 0;
  width: 1px;
  background: var(--line);
}

.step:last-child::before {
  content: none;
}

.step::after {
  content: "";
  position: absolute;
  left: 0.25rem;
  top: 0.3rem;
  width: 0.6rem;
  height: 0.6rem;
  border-radius: 50%;
  border: 2px solid var(--gold);
  background: var(--ink-0);
  transition: background-color 0.3s var(--ease), box-shadow 0.3s var(--ease), border-color 0.3s var(--ease);
}

.step:hover::after {
  background: var(--gold-hi);
  border-color: var(--gold-hi);
  box-shadow: 0 0 0 5px rgba(201, 162, 39, 0.14);
}

.step__idx {
  display: block;
  font-family: var(--font-latin), var(--font-cjk);
  font-size: var(--step-12);
  letter-spacing: 0.16em;
  color: var(--mist);
}

.step__title {
  margin: 0.4rem 0 0;
  font-size: var(--step-17);
  font-weight: 900;
  letter-spacing: -0.01em;
  color: var(--cloud);
}

.step__desc {
  margin: 0.45rem 0 0;
  max-width: 40em;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--mist);
}

.step__out {
  display: inline-block;
  margin: 0.6rem 0 0;
  padding: 0.2rem 0 0;
  font-size: var(--step-12);
  letter-spacing: 0.06em;
  color: var(--teal-deep);
  border-top: 1px solid var(--line);
  transition: color 0.3s var(--ease), border-color 0.3s var(--ease);
}

.step:hover .step__out {
  color: var(--gold-hi);
  border-color: var(--gold);
}

/* ---------- 移动端适配 ---------- */

.page-about__facts {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.9rem;
}

.page-about__facts li {
  display: grid;
  grid-template-columns: 3.5rem minmax(0, 1fr);
  gap: 0.9rem;
  align-items: baseline;
  padding-bottom: 0.9rem;
  border-bottom: 1px solid var(--line);
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--mist);
}

.page-about__facts .num {
  font-family: var(--font-latin), var(--font-cjk);
  font-size: var(--step-22);
  font-weight: 700;
  line-height: 1.1;
  color: var(--gold);
  font-variant-numeric: tabular-nums;
  text-align: right;
}

.page-about__facts li > span:last-child {
  min-width: 0;
}

/* ---------- 支持响应 ---------- */

.page-about__support {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1rem;
}

@media (min-width: 680px) {
  .page-about__support {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

.support-card {
  padding: 1.25rem 1.15rem 1.35rem;
  background: var(--ink-1);
  border: 2px solid var(--line);
  border-top: 3px solid var(--gold);
}

.support-card__k {
  margin: 0;
  font-family: var(--font-latin), var(--font-cjk);
  font-size: var(--step-12);
  letter-spacing: 0.16em;
  color: var(--mist);
}

.support-card__v {
  margin: 0.65rem 0 0;
  font-size: clamp(1.15rem, 3.6vw, 1.375rem);
  font-weight: 700;
  line-height: 1.35;
  color: var(--cloud);
  font-variant-numeric: tabular-nums;
}

.support-card__n {
  margin: 0.6rem 0 0;
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--mist);
}

.page-about__prep {
  margin-top: 1.25rem;
  padding: 1.35rem 1.2rem 1.45rem;
  border: 1px solid var(--line);
  background: linear-gradient(140deg, rgba(156, 58, 34, 0.18), rgba(78, 124, 122, 0.14));
}

.page-about__prep h3 {
  margin: 0;
  font-size: var(--step-17);
  font-weight: 900;
  letter-spacing: -0.01em;
  color: var(--cloud);
}

.page-about__prep ul {
  list-style: none;
  margin: 0.9rem 0 0;
  padding: 0;
  display: grid;
  gap: 0.6rem;
}

.page-about__prep li {
  position: relative;
  padding-left: 1.15rem;
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--cloud);
  opacity: 0.86;
}

.page-about__prep li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.7em;
  width: 0.5rem;
  height: 1px;
  background: var(--gold);
}

.page-about__prep-link {
  margin: 1.1rem 0 0;
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--mist);
}

/* ---------- 发展历程 ---------- */

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

.era {
  border-bottom: 1px solid var(--line);
}

.era__summary {
  display: grid;
  gap: 0.3rem;
  padding: 1.05rem 0;
  cursor: pointer;
  list-style: none;
}

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

@media (min-width: 640px) {
  .era__summary {
    grid-template-columns: 7.5rem minmax(0, 1fr);
    gap: 1rem;
    align-items: baseline;
  }
}

.era__tag {
  font-family: var(--font-latin), var(--font-cjk);
  font-size: var(--step-12);
  letter-spacing: 0.14em;
  color: var(--gold);
}

.era__name {
  font-size: var(--step-17);
  font-weight: 900;
  letter-spacing: -0.01em;
  color: var(--cloud);
  transition: color 0.25s var(--ease);
}

.era__name::after {
  content: " ＋";
  font-weight: 400;
  color: var(--gold);
}

details[open] .era__name::after {
  content: " －";
}

.era__summary:hover .era__name {
  color: var(--gold-hi);
}

.era__summary:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: 3px;
}

.era__body {
  padding: 0 0 1.35rem;
  animation: about-era-in 0.28s var(--ease);
}

.era__body p {
  margin: 0;
  max-width: 42em;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--mist);
}

@keyframes about-era-in {
  from {
    opacity: 0;
    transform: translateY(-5px);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

.page-about__eras-link,
.page-about__partners-link {
  margin: 1.25rem 0 0;
  max-width: 42em;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--mist);
}

/* ---------- 内容合作 ---------- */

.page-about__collab {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 1rem;
  align-items: center;
  padding: 1.1rem 1.2rem;
  border: 2px solid var(--line);
  border-left: 4px solid var(--copper);
  background: var(--ink-1);
}

.page-about__collab-num {
  margin: 0;
  font-family: var(--font-latin), var(--font-cjk);
  font-size: clamp(2.2rem, 8vw, 3.25rem);
  font-weight: 700;
  line-height: 1;
  color: var(--gold);
  font-variant-numeric: tabular-nums;
}

.page-about__collab-cap {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--cloud);
}

.page-about__partners {
  list-style: none;
  margin: 1.25rem 0 0;
  padding: 0;
  display: grid;
  gap: 1rem;
}

@media (min-width: 720px) {
  .page-about__partners {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

.page-about__partners li {
  padding: 1rem 0 1.15rem;
  border-top: 1px solid var(--gold);
}

.page-about__partners h3 {
  margin: 0;
  font-size: 1rem;
  font-weight: 900;
  letter-spacing: -0.01em;
  color: var(--cloud);
}

.page-about__partners p {
  margin: 0.55rem 0 0;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--mist);
}

/* ---------- 收束 ---------- */

.page-about__outro {
  margin-top: clamp(3.5rem, 9vw, 8rem);
}

.page-about__outro-grid {
  display: grid;
  gap: 1.25rem;
  margin-top: clamp(1.25rem, 3vw, 2rem);
}

@media (min-width: 780px) {
  .page-about__outro-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: end;
  }
}

.page-about__outro-text {
  margin: 0;
  max-width: 40em;
  font-size: var(--step-17);
  line-height: 1.8;
  color: var(--cloud);
}

.page-about__stamp {
  margin: 0;
  font-family: var(--font-latin), var(--font-cjk);
  font-size: var(--step-12);
  letter-spacing: 0.16em;
  color: var(--mist);
  text-align: left;
}

@media (min-width: 780px) {
  .page-about__stamp {
    text-align: right;
  }
}

/* 站内链接统一样式（仅本页作用域） */

.page-about a {
  color: var(--gold);
  text-decoration: none;
  border-bottom: 1px solid rgba(201, 162, 39, 0.4);
  transition: color 0.25s var(--ease), border-color 0.25s var(--ease);
}

.page-about a:hover,
.page-about a:focus-visible {
  color: var(--gold-hi);
  border-bottom-color: var(--gold-hi);
}

.page-about a:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: 2px;
}

.page-about .breadcrumbs a {
  border-bottom: 0;
  color: var(--mist);
}

.page-about .breadcrumbs a:hover,
.page-about .breadcrumbs a:focus-visible {
  color: var(--gold);
}

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
  .page-about .era__body {
    animation: none;
  }
}
</main>