.page-about {
  --about-gap: 1rem;
  --about-pad: 2.75rem;
}

.page-about .breadcrumb {
  padding: 1.1rem 0 0.4rem;
  font-size: 0.82rem;
  color: var(--sage);
}

.page-about .breadcrumb a {
  color: var(--sage);
  text-decoration: none;
}

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

.page-about .breadcrumb span[aria-hidden="true"] {
  margin: 0 0.45rem;
  color: var(--line);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: 1.25rem 0 2.5rem;
  border-bottom: 1px solid var(--line);
  background:
    radial-gradient(120% 90% at 92% 0%, rgba(242, 193, 78, 0.12), transparent 62%),
    linear-gradient(180deg, #0e1a16 0%, var(--ink) 100%);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: repeating-linear-gradient(
    180deg,
    rgba(232, 240, 236, 0.035) 0px,
    rgba(232, 240, 236, 0.035) 1px,
    transparent 1px,
    transparent 5px
  );
  opacity: 0.6;
}

.page-about .about-hero__grid {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 1.75rem;
}

.page-about .about-hero__title {
  margin: 0.5rem 0 0;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(2rem, 7.5vw, 3.5rem);
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--mist);
}

.page-about .about-hero__title::after {
  content: "";
  display: block;
  width: 4.5rem;
  height: 3px;
  margin-top: 1.1rem;
  background: var(--gold);
}

.page-about .about-hero .lede {
  margin-top: 1.1rem;
  max-width: 60ch;
  color: var(--sage);
  font-size: 1rem;
  line-height: 1.8;
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1.5rem;
}

.page-about .about-hero__aside {
  border: 1px solid var(--line);
  border-left: 2px solid var(--gold);
  background: var(--carbon);
  padding: 0.9rem 1.1rem;
}

.page-about .fact {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 1rem;
  margin: 0;
  padding: 0.6rem 0;
  border-bottom: 1px dashed var(--line);
}

.page-about .fact:last-child {
  border-bottom: 0;
}

.page-about .fact__label {
  color: var(--sage);
  font-size: 0.78rem;
  letter-spacing: 0.08em;
}

.page-about .fact__value {
  color: var(--mist);
  font-size: 0.98rem;
  font-weight: 600;
}

.page-about .fact__value.mono {
  color: var(--cyan);
}

/* ---------- 章节骨架 ---------- */
.page-about .chapter {
  padding: var(--about-pad) 0;
  border-bottom: 1px solid var(--line);
}

.page-about .chapter--last {
  border-bottom: 0;
  padding-bottom: 3.5rem;
}

.page-about .chapter__head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 0.75rem 1rem;
  align-items: start;
  margin-bottom: 1.75rem;
}

.page-about .chapter__index {
  font-size: 2rem;
  line-height: 1;
  font-weight: 700;
  color: var(--gold);
  letter-spacing: -0.03em;
}

.page-about .chapter .section-title {
  margin: 0;
  color: var(--mist);
  font-size: clamp(1.35rem, 4.2vw, 1.9rem);
  line-height: 1.25;
}

.page-about .chapter__lede {
  max-width: 62ch;
  margin: 0.7rem 0 0;
  color: var(--sage);
  font-size: 0.94rem;
  line-height: 1.8;
}

/* ---------- 01 方法 ---------- */
.page-about .method-grid {
  display: grid;
  gap: var(--about-gap);
  grid-template-columns: minmax(0, 1fr);
}

.page-about .method-card {
  position: relative;
  border: 1px solid var(--line);
  background: var(--carbon);
  padding: 1.2rem 1rem 1.1rem;
  transition: border-color 0.25s var(--ease), transform 0.25s var(--ease);
}

.page-about .method-card::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 2.25rem;
  height: 2px;
  background: var(--gold);
}

.page-about .method-card:hover {
  border-color: rgba(242, 193, 78, 0.55);
  transform: translateY(-3px);
}

.page-about .method-card__num {
  display: inline-block;
  font-size: 0.78rem;
  letter-spacing: 0.14em;
  color: var(--gold);
}

.page-about .method-card h3 {
  margin: 0.55rem 0 0.5rem;
  color: var(--mist);
  font-size: 1.02rem;
  line-height: 1.4;
}

.page-about .method-card p {
  margin: 0;
  color: var(--sage);
  font-size: 0.88rem;
  line-height: 1.75;
}

.page-about .about-media {
  margin: 1.75rem 0 0;
  overflow: hidden;
  border: 1px solid var(--line);
  background: var(--carbon);
}

.page-about .about-media img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  filter: saturate(0.78) brightness(0.92);
}

.page-about .about-media figcaption {
  padding: 0.65rem 1rem 0.8rem;
  border-top: 1px solid var(--line);
  color: var(--sage);
  font-size: 0.78rem;
  line-height: 1.6;
  letter-spacing: 0.02em;
}

/* ---------- 02 工作流 ---------- */
.page-about .workflow-layout {
  display: grid;
  gap: 1.5rem;
}

.page-about .flow {
  border-top: 1px solid var(--line);
}

.page-about .flow-item {
  border-bottom: 1px solid var(--line);
}

.page-about .flow-item summary {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  gap: 0.85rem;
  align-items: center;
  padding: 0.95rem 0.15rem;
  cursor: pointer;
  list-style: none;
}

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

.page-about .flow-item summary::after {
  content: "+";
  color: var(--cyan);
  font-size: 1.1rem;
  line-height: 1;
}

.page-about .flow-item[open] summary::after {
  content: "−";
}

.page-about .flow-item__step {
  font-size: 0.76rem;
  letter-spacing: 0.12em;
  color: var(--gold);
}

.page-about .flow-item__title {
  color: var(--mist);
  font-size: 0.98rem;
  font-weight: 600;
  line-height: 1.45;
}

.page-about .flow-item[open] .flow-item__title {
  color: var(--gold);
}

.page-about .flow-item__body {
  padding: 0 0.15rem 1.1rem 2.55rem;
  border-left: 1px solid transparent;
}

.page-about .flow-item__body p {
  margin: 0;
  color: var(--sage);
  font-size: 0.9rem;
  line-height: 1.8;
}

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

.page-about .about-side-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  filter: saturate(0.8) brightness(0.9);
}

.page-about .about-side-figure figcaption {
  padding: 0.65rem 0.9rem 0.75rem;
  border-top: 1px solid var(--line);
  color: var(--sage);
  font-size: 0.76rem;
  line-height: 1.6;
}

/* ---------- 斜切分隔 ---------- */
.page-about .about-divider {
  position: relative;
  height: 3.25rem;
  overflow: hidden;
}

.page-about .about-divider::before {
  content: "";
  position: absolute;
  left: -5%;
  right: -5%;
  top: 50%;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--gold) 35%, var(--gold) 65%, transparent);
  transform: rotate(-1.8deg);
  opacity: 0.65;
}

/* ---------- 03 里程碑 ---------- */
.page-about .about-timeline {
  position: relative;
  border-left: 1px solid var(--line);
  padding-left: 1.5rem;
}

.page-about .milestone {
  position: relative;
  padding: 0.55rem 0;
}

.page-about .milestone::before {
  content: "";
  position: absolute;
  left: -1.72rem;
  top: 1.15rem;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 0 3px rgba(49, 230, 214, 0.14);
}

.page-about .milestone--now::before {
  background: var(--orange);
  box-shadow: 0 0 0 3px rgba(255, 107, 53, 0.18);
}

.page-about .milestone summary {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 0.9rem;
  align-items: baseline;
  padding: 0.45rem 0;
  cursor: pointer;
  list-style: none;
}

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

.page-about .milestone__year {
  min-width: 3.2rem;
  font-size: 0.85rem;
  letter-spacing: 0.06em;
  color: var(--gold);
}

.page-about .milestone__title {
  color: var(--mist);
  font-size: 1rem;
  font-weight: 600;
  line-height: 1.5;
  transition: color 0.2s var(--ease);
}

.page-about .milestone:hover .milestone__title,
.page-about .milestone summary:focus-visible .milestone__title {
  color: var(--gold);
}

.page-about .milestone__detail {
  margin: 0.35rem 0 0.6rem;
  padding: 0.75rem 0.9rem;
  border-left: 2px solid var(--line);
  background: rgba(22, 30, 27, 0.85);
  color: var(--sage);
  font-size: 0.88rem;
  line-height: 1.8;
}

.page-about .milestone--now .milestone__detail {
  border-left-color: var(--orange);
}

.page-about .about-media--wide {
  margin-top: 1.75rem;
}

/* ---------- 04 团队 ---------- */
.page-about .team-layout {
  display: grid;
  gap: 1.25rem;
}

.page-about .team-lead {
  border: 1px solid var(--line);
  background: linear-gradient(150deg, rgba(242, 193, 78, 0.1), rgba(49, 230, 214, 0.05));
  padding: 1.35rem 1.1rem;
}

.page-about .big-stat__value {
  display: block;
  font-size: clamp(2.2rem, 8vw, 3.2rem);
  line-height: 1;
  font-weight: 700;
  color: var(--cyan);
  letter-spacing: -0.03em;
}

.page-about .team-lead .big-stat__value {
  color: var(--gold);
  font-size: clamp(2.8rem, 11vw, 4rem);
}

.page-about .big-stat__label {
  display: block;
  margin-top: 0.5rem;
  color: var(--sage);
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  line-height: 1.6;
}

.page-about .team-lead__text {
  margin: 1rem 0 0;
  color: var(--mist);
  font-size: 0.9rem;
  line-height: 1.8;
}

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

.page-about .role-list li {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 0.15rem 0.9rem;
  padding: 0.85rem 0.15rem;
  border-bottom: 1px solid var(--line);
}

.page-about .role-list__num {
  grid-row: span 2;
  align-self: center;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--cyan);
}

.page-about .role-list__name {
  color: var(--mist);
  font-size: 0.95rem;
  font-weight: 600;
}

.page-about .role-list__desc {
  color: var(--sage);
  font-size: 0.84rem;
  line-height: 1.7;
}

.page-about .team-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.75rem;
  margin-top: 1.5rem;
}

.page-about .big-stat {
  border: 1px solid var(--line);
  background: var(--carbon);
  padding: 1rem 0.85rem;
}

.page-about .team-note {
  margin: 1.4rem 0 0;
  padding-left: 0.9rem;
  border-left: 2px solid var(--gold);
  color: var(--sage);
  font-size: 0.9rem;
  line-height: 1.8;
}

.page-about .team-note a,
.page-about .reach-band__text a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(49, 230, 214, 0.4);
}

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

/* ---------- 05 联系 ---------- */
.page-about .reach-band {
  display: grid;
  gap: 1.25rem;
  border: 1px solid var(--line);
  border-top: 2px solid var(--gold);
  background: var(--carbon);
  padding: 1.35rem 1.1rem;
}

.page-about .reach-band__text h3 {
  margin: 0 0 0.6rem;
  color: var(--mist);
  font-size: 1.1rem;
}

.page-about .reach-band__text p {
  margin: 0;
  color: var(--sage);
  font-size: 0.9rem;
  line-height: 1.85;
}

.page-about .contact-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.4rem 0.75rem;
  margin: 0;
  padding: 0.6rem 0;
  border-bottom: 1px dashed var(--line);
}

.page-about .contact-label {
  min-width: 2.6rem;
  color: var(--sage);
  font-size: 0.76rem;
  letter-spacing: 0.1em;
}

.page-about .contact-value {
  flex: 1 1 auto;
  min-width: 0;
  color: var(--mist);
  font-size: 0.92rem;
  word-break: break-word;
}

.page-about .contact-row .copy-button {
  flex: 0 0 auto;
}

.page-about .contact-note {
  margin: 0.85rem 0 0;
  color: var(--sage);
  font-size: 0.78rem;
  line-height: 1.75;
}

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

@media (min-width: 900px) {
  .page-about {
    --about-pad: 3.5rem;
  }

  .page-about .about-hero {
    padding: 2rem 0 3.25rem;
  }

  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.7fr) minmax(230px, 0.8fr);
    align-items: end;
    gap: 3rem;
  }

  .page-about .chapter__head {
    gap: 1rem 1.5rem;
  }

  .page-about .chapter__index {
    font-size: 3.4rem;
  }

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

  .page-about .workflow-layout {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr);
    align-items: start;
    gap: 2rem;
  }

  .page-about .about-side-figure {
    position: sticky;
    top: 1.5rem;
  }

  .page-about .team-layout {
    grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.4fr);
    align-items: start;
    gap: 2rem;
  }

  .page-about .team-stats {
    margin-top: 1.75rem;
  }

  .page-about .reach-band {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.1fr);
    gap: 2.25rem;
    padding: 1.75rem 1.6rem;
  }

  .page-about .about-media figcaption {
    padding: 0.75rem 1.25rem 0.9rem;
  }
}

@media (min-width: 1120px) {
  .page-about .method-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .method-card:nth-child(2n) {
    margin-top: 1.9rem;
  }

  .page-about .about-timeline {
    padding-left: 2rem;
  }

  .page-about .milestone::before {
    left: -2.22rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .method-card,
  .page-about .milestone__title {
    transition: none;
  }

  .page-about .method-card:hover {
    transform: none;
  }
}