.page-about {
  --about-rail-w: 64px;
  --about-sticky-top: 104px;
  background: var(--nacre);
  color: var(--text);
  overflow-x: hidden;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-block: clamp(1.25rem, 3vw, 2rem) clamp(2.5rem, 6vw, 4rem);
}

.page-about .about-hero__eyebrow {
  margin: clamp(1.25rem, 3vw, 2rem) 0 0;
  font-family: var(--font-mono);
  font-size: var(--f-12);
  letter-spacing: 0.08em;
  color: var(--ink-700);
}

.page-about .about-hero__title {
  margin: 0.55rem 0 1.25rem;
  font-family: var(--font-head);
  font-size: clamp(2.25rem, 7.6vw, 5.5rem);
  font-weight: 900;
  line-height: 1.05;
  letter-spacing: -0.015em;
  color: var(--ink-900);
  max-width: 11em;
}

.page-about .about-hero__lede {
  margin: 0;
  font-family: var(--font-body);
  font-size: var(--f-20);
  line-height: 1.8;
  color: var(--text);
  max-width: 32em;
}

.page-about .about-facts {
  list-style: none;
  margin: clamp(1.75rem, 4vw, 2.75rem) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--nacre-2);
  border: var(--hairline);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.page-about .about-facts li {
  background: var(--nacre);
  padding: 0.95rem 1rem 1.1rem;
  min-width: 0;
}

.page-about .about-facts strong {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--f-28);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: 0.02em;
  color: var(--ink-900);
}

.page-about .about-facts span {
  display: block;
  margin-top: 0.35rem;
  font-size: var(--f-12);
  line-height: 1.6;
  color: var(--ink-700);
}

@media (min-width: 760px) {
  .page-about .about-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ---------- 章节骨架：左侧编号栏 ---------- */
.page-about .about-sec {
  padding-block: clamp(2.25rem, 5vw, 3.5rem);
}

.page-about .about-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0.9rem;
}

.page-about .about-rail {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  padding-bottom: 0.6rem;
  border-bottom: var(--hairline);
}

.page-about .about-rail__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--f-28);
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--ink-700);
  opacity: 0.42;
  transition: color 240ms var(--ease), opacity 240ms var(--ease), transform 240ms var(--ease);
}

.page-about .about-rail__num.is-active {
  color: var(--coral);
  opacity: 1;
  transform: translateX(4px);
}

.page-about .about-rail__label {
  margin: 0;
  font-family: var(--font-head);
  font-size: var(--f-12);
  letter-spacing: 0.24em;
  color: var(--ink-700);
}

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

@media (min-width: 960px) {
  .page-about .about-grid {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    column-gap: clamp(1.75rem, 3vw, 3rem);
  }

  .page-about .about-rail {
    position: sticky;
    top: var(--about-sticky-top);
    align-self: start;
    flex-direction: column;
    gap: 0.95rem;
    padding-bottom: 0;
    border-bottom: 0;
    text-align: center;
  }

  .page-about .about-rail__label {
    writing-mode: vertical-rl;
    letter-spacing: 0.42em;
  }

  .page-about .about-rail__num.is-active {
    transform: translateY(-4px);
  }
}

/* ---------- 标题与正文 ---------- */
.page-about .about-head {
  margin-bottom: clamp(1rem, 2.5vw, 1.75rem);
}

.page-about .about-title {
  margin: 0;
  font-family: var(--font-head);
  font-size: var(--f-28);
  font-weight: 800;
  line-height: 1.22;
  letter-spacing: -0.01em;
  color: var(--ink-900);
  max-width: 20em;
}

@media (min-width: 960px) {
  .page-about .about-title {
    font-size: var(--f-36);
    max-width: 18em;
  }
}

.page-about .about-prose {
  margin: 0;
  font-family: var(--font-body);
  font-size: var(--f-16);
  line-height: 1.85;
  color: var(--text);
  max-width: 34em;
}

.page-about .about-prose--gap {
  margin-top: 1.4rem;
}

.page-about .about-prose a {
  color: var(--ink-700);
  text-decoration: none;
  border-bottom: 1px solid var(--coral);
}

.page-about .about-prose a:hover {
  color: var(--coral);
}

/* ---------- 01 定位与主张 ---------- */
.page-about .about-roles {
  list-style: none;
  margin: 1.75rem 0 0;
  padding: 0;
  display: grid;
  gap: 0.9rem;
}

.page-about .about-roles li {
  border-left: 3px solid var(--ink-700);
  padding: 0.15rem 0 0.15rem 1rem;
}

.page-about .about-roles li:nth-child(2) {
  border-left-color: var(--coral);
}

.page-about .about-roles li:nth-child(3) {
  border-left-color: var(--cyan);
}

.page-about .about-roles__k {
  margin: 0 0 0.3rem;
  font-family: var(--font-head);
  font-size: var(--f-16);
  font-weight: 700;
  color: var(--ink-900);
}

.page-about .about-roles p {
  margin: 0;
  font-family: var(--font-body);
  font-size: var(--f-16);
  line-height: 1.8;
  color: var(--text);
  max-width: 32em;
}

@media (min-width: 860px) {
  .page-about .about-roles {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1.5rem;
  }
}

/* ---------- 02 发展历程 ---------- */
.page-about .about-figure {
  margin: 0 0 clamp(1.5rem, 4vw, 2.25rem);
  overflow: hidden;
  border-radius: var(--radius);
}

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

.page-about .about-figure .media__caption {
  margin-top: 0.6rem;
  font-family: var(--font-mono);
  font-size: var(--f-12);
  letter-spacing: 0.04em;
  color: var(--ink-700);
}

.page-about .about-stages {
  display: grid;
  gap: 0;
}

.page-about .about-stage {
  border-top: var(--hairline);
}

.page-about .about-stage:last-child {
  border-bottom: var(--hairline);
}

.page-about .about-stage__sum {
  display: grid;
  grid-template-columns: 2.6rem minmax(0, 1fr) auto;
  align-items: baseline;
  gap: 0.25rem 0.8rem;
  padding: 0.95rem 0;
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-stage__sum::after {
  content: "+";
  grid-column: 3;
  grid-row: 1;
  font-family: var(--font-mono);
  font-size: var(--f-16);
  font-weight: 700;
  color: var(--coral);
}

.page-about .about-stage[open] .about-stage__sum::after {
  content: "−";
}

.page-about .about-stage__num {
  grid-column: 1;
  grid-row: 1 / span 2;
  font-family: var(--font-mono);
  font-size: var(--f-16);
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--ink-700);
}

.page-about .about-stage[open] .about-stage__num {
  color: var(--coral);
}

.page-about .about-stage__name {
  grid-column: 2;
  grid-row: 1;
  font-family: var(--font-head);
  font-size: var(--f-20);
  font-weight: 700;
  color: var(--ink-900);
  line-height: 1.4;
}

.page-about .about-stage__res {
  grid-column: 2;
  grid-row: 2;
  font-size: var(--f-12);
  line-height: 1.6;
  color: var(--ink-700);
}

.page-about .about-stage__body {
  padding: 0 0 1.15rem 3.4rem;
}

.page-about .about-stage__body p {
  margin: 0;
  font-family: var(--font-body);
  font-size: var(--f-16);
  line-height: 1.85;
  color: var(--text);
  max-width: 34em;
}

@media (min-width: 960px) {
  .page-about .about-stage__sum {
    grid-template-columns: 3.2rem minmax(0, 1fr) auto;
  }

  .page-about .about-stage__body {
    padding-left: 4rem;
  }
}

/* ---------- 03 团队与分工 ---------- */
.page-about .about-team {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1.5rem;
  align-items: start;
}

.page-about .about-team__main {
  min-width: 0;
}

.page-about .about-team__fig {
  margin: 0;
  overflow: hidden;
  border-radius: var(--radius);
}

.page-about .about-bars {
  list-style: none;
  margin: 1.5rem 0 0;
  padding: 0;
  display: grid;
  gap: 0.85rem;
}

.page-about .about-bars li {
  display: grid;
  grid-template-columns: 5rem minmax(0, 1fr) 3rem;
  align-items: center;
  gap: 0.7rem;
}

.page-about .about-bars__label {
  font-family: var(--font-head);
  font-size: var(--f-12);
  color: var(--ink-900);
  letter-spacing: 0.02em;
  white-space: nowrap;
}

.page-about .about-bars__track {
  display: block;
  height: 10px;
  background: var(--nacre-2);
  border-radius: var(--pill);
  overflow: hidden;
  min-width: 0;
}

.page-about .about-bars__fill {
  display: block;
  height: 100%;
  width: 47%;
  border-radius: var(--pill);
  background: var(--ink-900);
}

.page-about .about-bars li:nth-child(2) .about-bars__fill {
  width: 26%;
  background: var(--coral);
}

.page-about .about-bars li:nth-child(3) .about-bars__fill {
  width: 16%;
  background: var(--ink-700);
}

.page-about .about-bars li:nth-child(4) .about-bars__fill {
  width: 10%;
  background: var(--cyan);
}

.page-about .about-bars__val {
  font-family: var(--font-mono);
  font-size: var(--f-12);
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--ink-900);
  text-align: right;
  white-space: nowrap;
}

@media (min-width: 880px) {
  .page-about .about-team {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    gap: 2rem;
  }
}

/* ---------- 04 交付方法 ---------- */
.page-about .about-steps {
  list-style: none;
  margin: 1.5rem 0 0;
  padding: 0;
  display: grid;
  gap: 1.15rem;
}

.page-about .about-steps li {
  display: grid;
  grid-template-columns: 2.6rem minmax(0, 1fr);
  gap: 0.2rem 0.85rem;
}

.page-about .about-steps__num {
  grid-column: 1;
  grid-row: 1 / span 2;
  font-family: var(--font-mono);
  font-size: var(--f-16);
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--coral);
  line-height: 1.5;
}

.page-about .about-steps__name {
  grid-column: 2;
  grid-row: 1;
  margin: 0;
  font-family: var(--font-head);
  font-size: var(--f-20);
  font-weight: 700;
  color: var(--ink-900);
  line-height: 1.4;
}

.page-about .about-steps__desc {
  grid-column: 2;
  grid-row: 2;
  margin: 0.15rem 0 0;
  font-family: var(--font-body);
  font-size: var(--f-16);
  line-height: 1.8;
  color: var(--text);
  max-width: 32em;
}

@media (min-width: 900px) {
  .page-about .about-steps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1.5rem 2.25rem;
  }
}

.page-about .about-rhythm {
  margin-top: clamp(1.5rem, 4vw, 2.25rem);
  border-left: 3px solid var(--cyan);
  border-radius: var(--radius-sm);
}

.page-about .about-rhythm p {
  margin: 0;
  font-family: var(--font-body);
  font-size: var(--f-16);
  line-height: 1.85;
  color: var(--text);
  max-width: 36em;
}

.page-about .about-rhythm a {
  color: var(--ink-900);
  font-weight: 700;
  text-decoration: none;
  border-bottom: 1px solid var(--coral);
}

/* ---------- 05 资质与生态 ---------- */
.page-about .about-cert-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1.5rem;
  align-items: start;
}

.page-about .about-certs {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.7rem;
}

.page-about .about-certs li {
  border: var(--hairline);
  border-radius: var(--radius-sm);
  padding: 1rem 1.1rem 1.15rem;
  background: #FCFAF5;
  min-width: 0;
}

.page-about .about-certs__id {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--f-12);
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--coral);
  margin-bottom: 0.45rem;
}

.page-about .about-certs__name {
  margin: 0 0 0.4rem;
  font-family: var(--font-head);
  font-size: var(--f-16);
  font-weight: 700;
  line-height: 1.45;
  color: var(--ink-900);
}

.page-about .about-certs__desc {
  margin: 0;
  font-family: var(--font-body);
  font-size: var(--f-16);
  line-height: 1.8;
  color: var(--text);
}

.page-about .about-cert-fig {
  margin: 0;
  overflow: hidden;
  border-radius: var(--radius);
}

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

@media (min-width: 1000px) {
  .page-about .about-cert-layout {
    grid-template-columns: minmax(0, 1.3fr) minmax(0, 0.7fr);
    gap: 2.25rem;
  }
}

.page-about .about-eco {
  margin-top: clamp(1.75rem, 4vw, 2.5rem);
  padding-top: clamp(1.5rem, 3vw, 2rem);
  border-top: var(--hairline);
}

.page-about .about-eco__nums {
  margin-top: 1.25rem;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0.9rem;
}

.page-about .about-eco__nums div {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  border-left: 3px solid var(--ink-700);
  padding-left: 0.9rem;
}

.page-about .about-eco__nums strong {
  font-family: var(--font-mono);
  font-size: var(--f-28);
  font-weight: 700;
  letter-spacing: 0.02em;
  line-height: 1;
  color: var(--ink-900);
  flex: 0 0 auto;
}

.page-about .about-eco__nums span {
  font-size: var(--f-12);
  line-height: 1.7;
  color: var(--ink-700);
}

@media (min-width: 760px) {
  .page-about .about-eco__nums {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1.5rem;
  }
}

/* ---------- 06 客户与服务 ---------- */
.page-about .about-metrics {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--nacre-2);
  border: var(--hairline);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.page-about .about-metrics li {
  background: var(--nacre);
  padding: 0.95rem 1rem 1.1rem;
  min-width: 0;
}

.page-about .about-metrics strong {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--f-28);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: 0.02em;
  color: var(--ink-900);
}

.page-about .about-metrics span {
  display: block;
  margin-top: 0.35rem;
  font-size: var(--f-12);
  line-height: 1.7;
  color: var(--ink-700);
}

@media (min-width: 760px) {
  .page-about .about-metrics {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.page-about .about-modes {
  margin-top: clamp(1.5rem, 4vw, 2.25rem);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0.75rem;
}

.page-about .about-mode {
  border: var(--hairline);
  border-radius: var(--radius-sm);
  padding: 1rem 1.1rem 1.2rem;
  background: #FCFAF5;
}

.page-about .about-mode__tag {
  display: inline-block;
  margin: 0 0 0.6rem;
  padding: 0.15rem 0.7rem;
  border-radius: var(--pill);
  background: var(--coral-mist);
  color: #8A2A0E;
  font-family: var(--font-mono);
  font-size: var(--f-12);
  letter-spacing: 0.08em;
}

.page-about .about-mode:nth-child(2) .about-mode__tag {
  background: var(--cyan-mist);
  color: #0A5A4C;
}

.page-about .about-mode__name {
  margin: 0 0 0.45rem;
  font-family: var(--font-head);
  font-size: var(--f-20);
  font-weight: 700;
  color: var(--ink-900);
}

.page-about .about-mode__desc {
  margin: 0;
  font-family: var(--font-body);
  font-size: var(--f-16);
  line-height: 1.8;
  color: var(--text);
}

@media (min-width: 860px) {
  .page-about .about-modes {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1.25rem;
  }
}

/* ---------- 收尾 ---------- */
.page-about .about-cta {
  background: var(--ink-900);
  color: var(--nacre);
  padding-block: clamp(2.5rem, 6vw, 4rem);
}

.page-about .about-cta__inner {
  max-width: 44rem;
}

.page-about .about-cta__eyebrow {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--f-12);
  letter-spacing: 0.1em;
  color: var(--cyan);
}

.page-about .about-cta__title {
  margin: 0.6rem 0 0.9rem;
  font-family: var(--font-head);
  font-size: var(--f-36);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.01em;
  color: var(--nacre);
  max-width: 14em;
}

.page-about .about-cta__text {
  margin: 0;
  font-family: var(--font-body);
  font-size: var(--f-16);
  line-height: 1.85;
  color: #C7D6E1;
  max-width: 32em;
}

.page-about .about-cta__btns {
  margin-top: 1.5rem;
}

.page-about .about-cta__more {
  margin: 1.5rem 0 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.5rem;
  font-family: var(--font-mono);
  font-size: var(--f-12);
  letter-spacing: 0.05em;
}

.page-about .about-cta__more a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(43, 227, 196, 0.45);
  padding-bottom: 0.1rem;
}

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