.page-about {
  --about-manifesto: clamp(2.1rem, 7.6vw, 5.25rem);
  --about-pad: clamp(1.25rem, 4vw, 2.5rem);
  background: var(--warm-bg);
}

.page-about .crumbs {
  padding-block: 1.5rem 0.5rem;
}

/* 首屏 */
.page-about .about-hero {
  display: grid;
  gap: 2.5rem;
  padding-block: 1.5rem 3rem;
}

.page-about .about-manifesto {
  margin: 0.6rem 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: var(--about-manifesto);
  line-height: 1.08;
  letter-spacing: -0.02em;
  color: var(--ink);
}

.page-about .about-manifesto__line {
  display: block;
  max-width: 13em;
}

.page-about .about-manifesto__line:nth-child(2) {
  color: var(--cinnabar);
}

.page-about .about-hero__lead {
  margin-top: 1.75rem;
  max-width: 34em;
  color: var(--charcoal);
  font-size: var(--fs-16);
  line-height: 1.85;
}

.page-about .about-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1.75rem;
}

.page-about .about-hero__stamp {
  display: grid;
  gap: 1.25rem;
  align-content: start;
}

.page-about .about-stampfig {
  margin: 0;
  position: relative;
  aspect-ratio: 7 / 10;
  overflow: hidden;
  background: var(--paper);
  border: 1px solid var(--line);
  clip-path: polygon(18px 0, 100% 0, 100% calc(100% - 28px), calc(100% - 28px) 100%, 0 100%, 0 18px);
}

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

.page-about .about-stampfig__cap {
  position: absolute;
  left: 0;
  bottom: 0;
  padding: 0.4rem 0.7rem;
  background: var(--ink);
  color: var(--night-text);
  font-size: var(--fs-12);
  letter-spacing: 0.06em;
}

.page-about .about-facts {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.5rem;
  border-top: 1px solid var(--line);
  padding-top: 0.9rem;
}

.page-about .about-fact {
  display: grid;
  gap: 0.15rem;
}

.page-about .about-fact__v {
  font-size: var(--fs-22);
  font-weight: 700;
  color: var(--cinnabar);
  line-height: 1.1;
}

.page-about .about-fact__k {
  font-size: var(--fs-12);
  color: var(--muted);
}

/* 斜线分隔带 */
.page-about .about-slash {
  height: 26px;
  background-image: repeating-linear-gradient(
    102deg,
    var(--cinnabar) 0 2px,
    transparent 2px 14px
  );
  opacity: 0.55;
}

.page-about .about-slash--bamboo {
  background-image: repeating-linear-gradient(
    102deg,
    var(--bamboo) 0 2px,
    transparent 2px 14px
  );
  opacity: 0.5;
}

/* 认证体系 */
.page-about .about-certs {
  display: grid;
  gap: 2rem;
}

.page-about .about-certs__intro h2,
.page-about .about-team__text h2,
.page-about .about-eco__col h2,
.page-about .about-reach__head h2,
.page-about .about-cta h2 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--fs-28);
  line-height: 1.35;
  color: var(--ink);
  margin: 0.4rem 0 1rem;
}

.page-about .about-certs__intro p {
  max-width: 32em;
  color: var(--charcoal);
  line-height: 1.85;
}

.page-about .about-note {
  font-size: var(--fs-14);
  color: var(--muted);
  border-left: 2px solid var(--gold);
  padding-left: 0.9rem;
  margin-top: 1.1rem;
}

.page-about .about-certs__list {
  display: grid;
  gap: 0.9rem;
  align-content: start;
}

.page-about .about-cert {
  background: var(--paper);
  border: 1px solid var(--line);
  clip-path: polygon(18px 0, 100% 0, 100% calc(100% - 28px), calc(100% - 28px) 100%, 0 100%, 0 18px);
}

.page-about .about-cert__sum {
  display: grid;
  grid-template-columns: 46px minmax(0, 1fr);
  gap: 0.9rem;
  align-items: start;
  padding: 1.1rem 1.2rem;
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-cert__seal {
  color: var(--cinnabar);
  display: block;
  line-height: 0;
}

.page-about .about-cert__seal svg {
  width: 46px;
  height: 46px;
}

.page-about .about-cert__body {
  display: grid;
  gap: 0.2rem;
}

.page-about .about-cert__idx {
  font-size: var(--fs-12);
  color: var(--bamboo);
  letter-spacing: 0.06em;
}

.page-about .about-cert__name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--fs-22);
  color: var(--ink);
  line-height: 1.3;
}

.page-about .about-cert__brief {
  font-size: var(--fs-14);
  color: var(--muted);
  line-height: 1.7;
}

.page-about .about-cert__detail {
  padding: 0 1.2rem 1.2rem 1.2rem;
  border-top: 1px dashed var(--line);
  margin-top: 0;
}

.page-about .about-cert__detail p {
  margin: 1rem 0 0;
  font-size: var(--fs-16);
  line-height: 1.85;
  color: var(--charcoal);
}

.page-about .about-cert[open] {
  border-color: var(--cinnabar-deep);
}

/* 时间线 */
.page-about .about-timeline {
  background: var(--paper);
  border-block: 1px solid var(--line);
  padding-block: 3rem;
}

.page-about .about-timeline h2 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--fs-28);
  color: var(--ink);
  margin: 0.4rem 0 1.75rem;
  line-height: 1.35;
}

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

.page-about .about-tl__item {
  border-bottom: 1px solid var(--line);
  position: relative;
}

.page-about .about-tl__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--bamboo);
  opacity: 0.35;
}

.page-about .about-tl__sum {
  display: grid;
  grid-template-columns: 4.2rem minmax(0, 1fr);
  gap: 0.3rem 1rem;
  padding: 1.1rem 0 1.1rem 1rem;
  cursor: pointer;
  list-style: none;
  transition: background 220ms var(--ease);
}

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

.page-about .about-tl__sum:hover,
.page-about .about-tl__sum:focus-visible {
  background: var(--bamboo-pale);
}

.page-about .about-tl__year {
  grid-row: span 2;
  font-size: var(--fs-18);
  font-weight: 700;
  color: var(--cinnabar);
  letter-spacing: 0.02em;
  padding-top: 0.1rem;
}

.page-about .about-tl__stage {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--fs-18);
  color: var(--ink);
  line-height: 1.4;
}

.page-about .about-tl__brief {
  font-size: var(--fs-14);
  color: var(--muted);
  line-height: 1.7;
}

.page-about .about-tl__more {
  margin: 0 0 1.1rem 5.2rem;
  padding-right: 1rem;
  font-size: var(--fs-14);
  line-height: 1.85;
  color: var(--charcoal);
  border-left: 2px solid var(--bamboo-pale);
  padding-left: 1rem;
}

/* 团队 */
.page-about .about-team {
  display: grid;
  gap: 2rem;
}

.page-about .about-team__media {
  margin: 0;
}

.page-about .about-team__media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  border: 1px solid var(--line);
  clip-path: polygon(18px 0, 100% 0, 100% calc(100% - 28px), calc(100% - 28px) 100%, 0 100%, 0 18px);
}

.page-about .about-team__cap {
  margin-top: 0.6rem;
  font-size: var(--fs-12);
  color: var(--muted);
  letter-spacing: 0.04em;
}

.page-about .about-team__text p {
  max-width: 34em;
  color: var(--charcoal);
  line-height: 1.85;
}

.page-about .about-roles {
  list-style: none;
  margin: 1.5rem 0 0;
  padding: 0;
  display: grid;
  gap: 1rem;
}

.page-about .about-role {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 0.2rem 0.9rem;
  align-items: baseline;
  border-top: 1px solid var(--line);
  padding-top: 0.8rem;
}

.page-about .about-role__n {
  grid-row: span 2;
  font-size: var(--fs-38);
  font-weight: 700;
  line-height: 1;
  color: var(--ink);
  letter-spacing: -0.02em;
}

.page-about .about-role__name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--fs-18);
  color: var(--cinnabar-deep);
}

.page-about .about-role__desc {
  font-size: var(--fs-14);
  color: var(--muted);
  line-height: 1.7;
}

/* 合作生态 */
.page-about .about-eco {
  display: grid;
  gap: 2rem;
}

.page-about .about-eco__col p {
  max-width: 32em;
  color: var(--charcoal);
  line-height: 1.85;
}

.page-about .about-eco__col--award {
  background: var(--paper);
  border: 1px solid var(--line);
  border-top: 3px solid var(--gold);
  padding: var(--about-pad);
  clip-path: polygon(18px 0, 100% 0, 100% calc(100% - 28px), calc(100% - 28px) 100%, 0 100%, 0 18px);
}

.page-about .about-eco__col--award .btn {
  margin-top: 1.25rem;
}

/* 覆盖 */
.page-about .about-reach__head h2 {
  max-width: 24em;
}

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

.page-about .about-reach__fig img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 11 / 7;
  object-fit: cover;
  border: 1px solid var(--line);
}

.page-about .about-reach__cap {
  margin-top: 0.6rem;
  font-size: var(--fs-12);
  color: var(--muted);
  letter-spacing: 0.04em;
}

.page-about .about-metrics {
  margin: 2rem 0 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0;
  border-top: 1px solid var(--line);
  border-left: 1px solid var(--line);
}

.page-about .about-metric {
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  padding: 1rem;
  background: var(--paper);
}

.page-about .about-metric dt {
  font-size: var(--fs-12);
  color: var(--muted);
  letter-spacing: 0.04em;
}

.page-about .about-metric dd {
  margin: 0.35rem 0 0;
  font-size: var(--fs-22);
  font-weight: 700;
  color: var(--ink);
  letter-spacing: -0.01em;
}

.page-about .about-rhythm {
  margin-top: 2.5rem;
}

.page-about .about-rhythm h3 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--fs-22);
  color: var(--ink);
  margin: 0 0 1rem;
}

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

.page-about .about-rhythm__list li {
  display: grid;
  grid-template-columns: 4.6rem minmax(0, 1fr);
  gap: 1rem;
  align-items: start;
  border-top: 1px solid var(--line);
  padding-top: 0.9rem;
}

.page-about .about-rhythm__k {
  font-size: var(--fs-14);
  color: var(--bamboo);
  font-weight: 700;
  letter-spacing: 0.04em;
}

.page-about .about-rhythm__v {
  font-size: var(--fs-14);
  color: var(--charcoal);
  line-height: 1.8;
}

/* 收尾 */
.page-about .about-cta__panel {
  padding: var(--about-pad);
}

.page-about .about-cta__eyebrow {
  color: var(--gold);
}

.page-about .about-cta h2 {
  color: var(--night-text);
  margin-bottom: 0.75rem;
}

.page-about .about-cta__text {
  max-width: 34em;
  color: var(--night-text);
  opacity: 0.82;
  line-height: 1.85;
  font-size: var(--fs-16);
}

.page-about .about-btn-onink {
  border-color: rgba(246, 242, 234, 0.45);
  color: var(--night-text);
}

.page-about .about-btn-onink:hover,
.page-about .about-btn-onink:focus-visible {
  background: var(--night-text);
  color: var(--ink);
  border-color: var(--night-text);
}

/* 平板以上 */
@media (min-width: 720px) {
  .page-about .about-roles {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1.25rem 1.75rem;
  }

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

  .page-about .about-team {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.15fr);
    align-items: start;
  }

  .page-about .about-team__media img {
    aspect-ratio: 3 / 4;
  }
}

/* 桌面 */
@media (min-width: 900px) {
  .page-about .about-hero {
    grid-template-columns: minmax(0, 1fr) 260px;
    gap: 3.5rem;
    padding-block: 2rem 4rem;
  }

  .page-about .about-hero__stamp {
    padding-top: 3.5rem;
  }

  .page-about .about-certs {
    grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
    gap: 0;
  }

  .page-about .about-certs__intro {
    padding-right: 2.5rem;
  }

  .page-about .about-certs__list {
    border-left: 1px dashed var(--line);
    padding-left: 2.5rem;
  }

  .page-about .about-eco {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.82fr);
    gap: 3rem;
    align-items: start;
  }

  .page-about .about-tl__sum {
    grid-template-columns: 6rem minmax(0, 12rem) minmax(0, 1fr);
    align-items: baseline;
  }

  .page-about .about-tl__year {
    grid-row: auto;
    font-size: var(--fs-22);
  }

  .page-about .about-tl__more {
    margin-left: 7rem;
    max-width: 40em;
  }

  .page-about .about-reach__fig {
    margin-top: 2.25rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-tl__sum {
    transition: none;
  }
}