.page-about {
  --ab-split: 116px;
  --ab-hair: 1px solid var(--line-ice);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding-block: clamp(1.75rem, 5vw, 3.5rem) clamp(2.5rem, 6vw, 5rem);
  background:
    radial-gradient(120% 95% at 100% 0%, rgba(106, 76, 255, .22), transparent 62%),
    radial-gradient(95% 75% at 0% 100%, rgba(43, 232, 176, .09), transparent 66%);
  border-bottom: var(--ab-hair);
  overflow: hidden;
}

.page-about .about-hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(1.75rem, 4vw, 3.5rem);
}

.page-about .about-hero-copy {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  min-width: 0;
}

.page-about .about-lede {
  max-width: 34ch;
  font-size: clamp(1rem, 1.15vw, 1.1rem);
  line-height: 1.85;
  color: var(--c-body);
}

.page-about .about-facts {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
  margin-top: .75rem;
  border-top: var(--ab-hair);
  padding-top: 1.25rem;
}

.page-about .about-fact {
  min-width: 0;
  padding-left: .85rem;
  border-left: 2px solid var(--c-neon);
}

.page-about .about-fact-label {
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--c-grit);
  text-transform: uppercase;
}

.page-about .about-fact-num {
  margin: .2rem 0 .3rem;
  font-family: var(--font-num);
  font-weight: 700;
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  line-height: 1;
  letter-spacing: .02em;
  color: var(--c-frost);
}

.page-about .about-fact-num em {
  margin-left: .15em;
  font-style: normal;
  font-size: .45em;
  color: var(--c-ice);
}

.page-about .about-fact-note {
  margin: 0;
  font-size: .82rem;
  line-height: 1.65;
  color: var(--c-grit);
}

.page-about .about-hero-media {
  margin: 0;
  align-self: stretch;
}

.page-about .about-hero-media img {
  display: block;
  width: 100%;
  height: 100%;
  min-height: 220px;
  object-fit: cover;
}

.page-about .about-hero-cap {
  margin-top: .7rem;
  font-size: .78rem;
  line-height: 1.6;
  color: var(--c-grit);
}

/* ---------- 时间轴长卷 ---------- */
.page-about .about-timeline {
  padding-block: clamp(2.5rem, 6vw, 5rem);
}

.page-about .about-timeline-head {
  padding-bottom: clamp(1.5rem, 4vw, 2.75rem);
}

.page-about .about-h2 {
  margin: .5rem 0 .9rem;
  font-size: clamp(1.5rem, 3.4vw, 2.35rem);
  line-height: 1.18;
  letter-spacing: -.015em;
  color: var(--c-frost);
  max-width: 26ch;
}

.page-about .about-intro {
  max-width: 46ch;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--c-body);
}

.page-about .about-chapter {
  position: relative;
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
  padding-block: clamp(1.75rem, 5vw, 3.25rem);
  border-top: var(--ab-hair);
}

.page-about .about-chapter:last-child {
  border-bottom: var(--ab-hair);
}

.page-about .about-chapter-rail {
  display: flex;
  align-items: baseline;
  gap: .75rem;
  margin-bottom: .9rem;
}

.page-about .about-chapter-num {
  font-family: var(--font-num);
  font-weight: 700;
  font-size: clamp(1.85rem, 4.2vw, 2.6rem);
  line-height: 1;
  letter-spacing: .06em;
  color: var(--c-violet);
}

.page-about .about-chapter-tag {
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--c-grit);
}

.page-about .about-chapter-body {
  min-width: 0;
}

.page-about .about-chapter-title {
  margin: 0 0 .9rem;
  font-size: clamp(1.15rem, 2.4vw, 1.6rem);
  line-height: 1.35;
  color: var(--c-frost);
}

.page-about .about-chapter-body p {
  max-width: 38em;
  margin: 0 0 .9rem;
  font-size: .97rem;
  line-height: 1.85;
  color: var(--c-body);
}

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

/* 转折章节：暖橙色带 */
.page-about .about-chapter--turn::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--c-orange) 0%, var(--c-orange-deep) 42%, transparent 100%);
}

/* ---------- 质量标准折叠 ---------- */
.page-about .about-details {
  margin-top: 1.4rem;
  border: var(--ab-hair);
  border-radius: var(--radius);
  background: var(--c-snow-deep);
}

.page-about .about-details summary {
  cursor: pointer;
  list-style: none;
  padding: .9rem 1.1rem;
  font-size: .92rem;
  font-weight: 700;
  color: var(--c-frost);
  transition: color var(--t) var(--ease), background var(--t) var(--ease);
}

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

.page-about .about-details summary::before {
  content: "+";
  display: inline-block;
  width: 1.2em;
  font-family: var(--font-num);
  color: var(--c-neon);
}

.page-about .about-details[open] summary::before {
  content: "−";
}

.page-about .about-details summary:hover,
.page-about .about-details summary:focus-visible {
  color: var(--c-neon);
  background: rgba(43, 232, 176, .06);
}

.page-about .about-details-body {
  padding: 0 1.1rem 1.15rem;
  border-top: var(--ab-hair);
}

.page-about .about-steps {
  margin: 0;
  padding: 1rem 0 0;
  list-style: none;
  counter-reset: ab-step;
}

.page-about .about-steps li {
  position: relative;
  counter-increment: ab-step;
  padding-left: 2.35rem;
  margin-bottom: 1rem;
  font-size: .9rem;
  line-height: 1.8;
  color: var(--c-body);
}

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

.page-about .about-steps li::before {
  content: counter(ab-step, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: .1rem;
  font-family: var(--font-num);
  font-size: .8rem;
  letter-spacing: .08em;
  color: var(--c-ice);
}

.page-about .about-steps strong {
  display: block;
  color: var(--c-frost);
  font-size: .95rem;
}

/* ---------- 三地团队 ---------- */
.page-about .about-team {
  list-style: none;
  margin: 1.4rem 0 0;
  padding: 0;
  border-top: var(--ab-hair);
}

.page-about .about-team-item {
  display: grid;
  grid-template-columns: 1fr;
  gap: .25rem;
  padding: 1.05rem 0;
  border-bottom: var(--ab-hair);
  transition: border-color var(--t) var(--ease);
}

.page-about .about-team-item:hover {
  border-bottom-color: var(--c-neon);
}

.page-about .about-team-city {
  font-size: 1.15rem;
  font-weight: 800;
  letter-spacing: .02em;
  color: var(--c-frost);
}

.page-about .about-team-role {
  font-family: var(--font-num);
  font-size: .74rem;
  letter-spacing: .1em;
  color: var(--c-ice);
}

.page-about .about-team-item p {
  margin: .35rem 0 0;
  max-width: 38em;
  font-size: .9rem;
  line-height: 1.8;
  color: var(--c-body);
}

.page-about .about-inline-media {
  margin: 1.75rem 0 0;
}

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

/* ---------- 合作生态 ---------- */
.page-about .about-eco {
  padding-block: clamp(2.5rem, 6vw, 5rem);
  border-top: var(--ab-hair);
  background:
    linear-gradient(180deg, rgba(18, 46, 69, .75) 0%, rgba(11, 27, 43, 0) 100%);
}

.page-about .about-eco-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(1.75rem, 4vw, 3.25rem);
}

.page-about .about-eco-copy {
  min-width: 0;
}

.page-about .about-eco-copy p {
  max-width: 40em;
  margin: 0 0 .9rem;
  font-size: .97rem;
  line-height: 1.85;
  color: var(--c-body);
}

.page-about .about-eco-nodes {
  list-style: none;
  margin: 1.5rem 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--line-soft);
  border: var(--ab-hair);
}

.page-about .about-eco-node {
  display: flex;
  align-items: baseline;
  gap: .85rem;
  padding: .85rem 1rem;
  background: var(--c-night);
  transition: background var(--t) var(--ease);
}

.page-about .about-eco-node:hover {
  background: var(--c-snow-deep);
}

.page-about .about-eco-num {
  font-family: var(--font-num);
  font-weight: 700;
  font-size: 1.35rem;
  letter-spacing: .04em;
  color: var(--c-neon);
  min-width: 3.2em;
}

.page-about .about-eco-label {
  font-size: .86rem;
  line-height: 1.5;
  color: var(--c-body);
}

.page-about .about-eco-media {
  margin: 0;
}

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

/* ---------- 行业认可 ---------- */
.page-about .about-honor {
  padding-block: clamp(2.25rem, 5vw, 4.25rem);
  border-top: var(--ab-hair);
}

.page-about .about-honor-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--line-soft);
  border-top: var(--ab-hair);
  border-bottom: var(--ab-hair);
}

.page-about .about-honor-list li {
  display: flex;
  align-items: baseline;
  gap: 1.1rem;
  padding: 1rem .25rem;
  background: var(--c-night);
}

.page-about .about-honor-year {
  font-family: var(--font-num);
  font-size: 1.05rem;
  letter-spacing: .08em;
  color: var(--c-orange);
  min-width: 4.5em;
}

.page-about .about-honor-name {
  font-size: 1rem;
  color: var(--c-frost);
}

.page-about .about-honor-note {
  max-width: 44ch;
  margin: 1.5rem 0 0;
  font-size: .92rem;
  line-height: 1.85;
  color: var(--c-grit);
}

/* ---------- 长期服务 ---------- */
.page-about .about-longterm {
  padding-block: clamp(2.5rem, 6vw, 5rem);
  border-top: var(--ab-hair);
}

.page-about .about-longterm-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin-top: 2rem;
  background: var(--line-soft);
  border: var(--ab-hair);
}

.page-about .about-longterm-item {
  padding: 1.5rem 1.25rem;
  background: var(--c-night);
  transition: box-shadow var(--t) var(--ease);
}

.page-about .about-longterm-item:hover {
  box-shadow: inset 0 0 0 1px var(--c-ice);
}

.page-about .about-longterm-item h3 {
  margin: 0 0 .7rem;
  font-size: 1.15rem;
  letter-spacing: .04em;
  color: var(--c-neon);
}

.page-about .about-longterm-item p {
  margin: 0 0 .8rem;
  max-width: 38em;
  font-size: .92rem;
  line-height: 1.85;
  color: var(--c-body);
}

.page-about .about-link {
  display: inline-block;
  font-size: .88rem;
  color: var(--c-frost);
  text-decoration: none;
  border-bottom: 1px solid var(--line-ice);
  padding-bottom: 2px;
  transition: color var(--t) var(--ease), border-color var(--t) var(--ease);
}

.page-about .about-link:hover,
.page-about .about-link:focus-visible {
  color: var(--c-orange);
  border-bottom-color: var(--c-orange);
}

.page-about .about-cta {
  margin-top: clamp(2rem, 5vw, 3.25rem);
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.25rem;
  align-items: center;
  padding: clamp(1.4rem, 3.5vw, 2rem);
  background: var(--c-snow-deep);
  border: var(--ab-hair);
  border-left: 3px solid var(--c-orange);
}

.page-about .about-cta-copy h3 {
  margin: 0 0 .4rem;
  font-size: clamp(1.1rem, 2.2vw, 1.35rem);
  color: var(--c-frost);
}

.page-about .about-cta-copy p {
  margin: 0;
  max-width: 42em;
  font-size: .92rem;
  line-height: 1.8;
  color: var(--c-body);
}

.page-about .about-cta .btn {
  justify-self: start;
}

/* ---------- 平板起的两栏 ---------- */
@media (min-width: 680px) {
  .page-about .about-facts {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1.25rem;
  }

  .page-about .about-team-item {
    grid-template-columns: 8.5rem minmax(0, 1fr);
    align-items: baseline;
    column-gap: 1.25rem;
  }

  .page-about .about-team-item p {
    grid-column: 2;
  }

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

  .page-about .about-eco-node {
    flex-direction: column;
    gap: .35rem;
    align-items: flex-start;
  }

  .page-about .about-honor-list {
    grid-template-columns: 1fr;
  }

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

  .page-about .about-cta {
    grid-template-columns: minmax(0, 1fr) auto;
  }
}

/* ---------- 桌面端：错位双栏 + 粘性编号 ---------- */
@media (min-width: 900px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 1.02fr) minmax(0, .98fr);
    align-items: end;
  }

  .page-about .about-chapter {
    grid-template-columns: var(--ab-split) minmax(0, 1fr);
    column-gap: clamp(1.75rem, 4vw, 3.5rem);
  }

  .page-about .about-chapter::before {
    content: "";
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 1px;
    background: var(--line-ice);
  }

  .page-about .about-chapter--turn::before {
    background: linear-gradient(180deg, var(--c-orange) 0%, var(--c-orange-deep) 60%, var(--line-ice) 100%);
    top: 0;
  }

  .page-about .about-chapter-rail {
    display: block;
    position: sticky;
    top: calc(var(--header-h-sm) + 1.75rem);
    align-self: start;
    margin-bottom: 0;
    padding-left: 1.4rem;
  }

  .page-about .about-chapter-tag {
    display: block;
    margin-top: .5rem;
  }

  .page-about .about-chapter-body {
    padding-right: clamp(0rem, 2vw, 2rem);
  }

  .page-about .about-chapter:nth-of-type(even) .about-chapter-body {
    padding-top: 1.75rem;
  }

  .page-about .about-eco-grid {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, .92fr);
    align-items: start;
  }

  .page-about .about-eco-media {
    position: sticky;
    top: calc(var(--header-h-sm) + 1.75rem);
  }
}

@media (min-width: 1200px) {
  .page-about .about-facts {
    gap: 1.75rem;
  }

  .page-about .about-chapter {
    padding-block: clamp(2.5rem, 4vw, 4rem);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-details summary,
  .page-about .about-team-item,
  .page-about .about-eco-node,
  .page-about .about-longterm-item,
  .page-about .about-link {
    transition-duration: 1ms;
  }
}