.page-about {
  padding-bottom: clamp(56px, 9vw, 112px);
}

.page-about .about-crumbs {
  padding-top: clamp(16px, 3vw, 28px);
}

/* ---------- 首屏框景 ---------- */
.page-about .about-hero {
  padding-top: clamp(14px, 2.6vw, 26px);
}

.page-about .about-hero__frame {
  position: relative;
  display: grid;
  gap: clamp(24px, 4vw, 46px);
  padding: clamp(22px, 4vw, 52px);
  border: 1px solid var(--c-line);
  background:
    radial-gradient(90% 120% at 0% 0%, var(--c-cyan-soft), transparent 58%),
    radial-gradient(80% 110% at 100% 100%, var(--c-violet-soft), transparent 62%),
    var(--c-panel);
  box-shadow: var(--shadow-glow);
}

.page-about .about-hero__frame::before,
.page-about .about-hero__frame::after {
  content: "";
  position: absolute;
  width: 14px;
  height: 14px;
  border: 1px solid var(--c-cyan);
  opacity: 0.75;
  pointer-events: none;
}

.page-about .about-hero__frame::before {
  top: -1px;
  left: -1px;
  border-right: 0;
  border-bottom: 0;
}

.page-about .about-hero__frame::after {
  bottom: -1px;
  right: -1px;
  border-left: 0;
  border-top: 0;
}

.page-about .about-hero__title {
  margin: 12px 0 0;
  font-family: var(--font-display);
  font-size: clamp(2.1rem, 5.2vw, 4rem);
  font-weight: 800;
  line-height: 1.08;
  letter-spacing: 0.02em;
  color: var(--c-paper);
}

.page-about .about-hero__lede {
  margin-top: 18px;
  max-width: 46ch;
  color: var(--c-steel);
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.85;
}

.page-about .about-hero__stats {
  list-style: none;
  margin: clamp(22px, 3vw, 32px) 0 0;
  padding: 20px 0 0;
  border-top: 1px solid var(--c-line);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px 20px;
}

.page-about .about-hero__stat-num {
  display: block;
  font-size: clamp(1.45rem, 3vw, 1.95rem);
  font-weight: 600;
  line-height: 1.1;
  letter-spacing: 0.02em;
  color: var(--c-cyan);
}

.page-about .about-hero__unit {
  margin-left: 2px;
  font-size: 0.55em;
  color: var(--c-steel);
  letter-spacing: 0;
}

.page-about .about-hero__stat-label {
  display: block;
  margin-top: 6px;
  font-size: 12.5px;
  line-height: 1.5;
  color: var(--c-steel);
}

.page-about .about-hero__media {
  margin: 0;
  border: 1px solid var(--c-line);
  background: var(--c-space);
}

.page-about .about-hero__media .media-frame__img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
}

.page-about .media-frame__caption {
  margin: 0;
  padding: 10px 14px;
  border-top: 1px solid var(--c-line);
  font-size: 12px;
  line-height: 1.65;
  color: var(--c-steel);
}

/* ---------- 章节索引 ---------- */
.page-about .chapter-index {
  margin-top: clamp(26px, 5vw, 52px);
  padding: 18px 0;
  border-top: 1px solid var(--c-line);
  border-bottom: 1px solid var(--c-line);
}

.page-about .chapter-index__caption {
  margin: 0 0 12px;
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--c-steel);
}

.page-about .chapter-index__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .chapter-index__link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 7px 12px;
  border: 1px solid var(--c-line);
  color: var(--c-paper);
  font-size: 13px;
  text-decoration: none;
  transition: border-color 0.25s var(--ease), color 0.25s var(--ease), background-color 0.25s var(--ease);
}

.page-about .chapter-index__link:hover,
.page-about .chapter-index__link:focus-visible {
  border-color: var(--c-cyan);
  color: var(--c-cyan);
  background: var(--c-cyan-soft);
  outline: none;
}

.page-about .chapter-index__num {
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--c-violet);
}

/* ---------- 章节骨架 ---------- */
.page-about .chapter {
  display: grid;
  gap: clamp(16px, 3vw, 32px);
  padding-block: clamp(36px, 6vw, 74px);
  border-bottom: 1px solid var(--c-line-soft);
  scroll-margin-top: 92px;
}

.page-about .chapter__num {
  display: block;
  font-size: clamp(2.8rem, 7vw, 4.4rem);
  font-weight: 700;
  line-height: 0.92;
  letter-spacing: 0.04em;
  color: transparent;
  -webkit-text-stroke: 1px var(--c-line);
  transition: color 0.3s var(--ease), -webkit-text-stroke-color 0.3s var(--ease);
}

.page-about .chapter:target .chapter__num {
  -webkit-text-stroke-color: var(--c-cyan);
  color: var(--c-cyan-soft);
}

.page-about .chapter__title {
  margin: 10px 0 0;
  font-family: var(--font-display);
  font-size: clamp(1.28rem, 2.4vw, 1.72rem);
  font-weight: 700;
  line-height: 1.34;
  letter-spacing: 0.02em;
  color: var(--c-paper);
}

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

.page-about .chapter__body p {
  margin: 0;
  color: var(--c-steel);
  font-size: 15.5px;
  line-height: 1.9;
}

.page-about .chapter__body p + p {
  margin-top: 14px;
}

.page-about .chapter__body .chapter__lead {
  color: var(--c-paper);
  font-size: clamp(15.5px, 1.7vw, 17px);
  line-height: 1.8;
}

.page-about .hl {
  font-family: var(--font-mono);
  font-size: 0.94em;
  letter-spacing: 0.02em;
  color: var(--c-cyan);
}

.page-about .inline-link {
  color: var(--c-cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(83, 243, 228, 0.4);
  transition: border-color 0.25s var(--ease), color 0.25s var(--ease);
}

.page-about .inline-link:hover,
.page-about .inline-link:focus-visible {
  color: var(--c-violet);
  border-bottom-color: var(--c-violet);
  outline: none;
}

/* ---------- 时间轴 ---------- */
.page-about .timeline {
  list-style: none;
  margin: clamp(20px, 3vw, 30px) 0 0;
  padding: 0 0 0 28px;
  border-left: 1px solid var(--c-line);
  display: grid;
  gap: clamp(20px, 3vw, 30px);
}

.page-about .timeline__item {
  position: relative;
  min-width: 0;
}

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  top: 7px;
  left: -28px;
  width: 10px;
  height: 10px;
  transform: translateX(-50%);
  border-radius: 50%;
  background: var(--c-space);
  border: 1px solid var(--c-cyan);
  box-shadow: 0 0 12px rgba(83, 243, 228, 0.45);
}

.page-about .timeline__year {
  margin: 0;
  font-size: 13px;
  letter-spacing: 0.12em;
  color: var(--c-cyan);
}

.page-about .timeline__title {
  margin: 6px 0 0;
  font-family: var(--font-display);
  font-size: 16.5px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--c-paper);
}

.page-about .timeline__desc {
  margin: 8px 0 0;
  color: var(--c-steel);
  font-size: 14.5px;
  line-height: 1.85;
}

.page-about .timeline-media,
.page-about .quality-media {
  margin: clamp(20px, 3vw, 30px) 0 0;
  border: 1px solid var(--c-line);
  background: var(--c-space);
}

.page-about .timeline-media .media-frame__img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  aspect-ratio: 16 / 5;
  object-fit: cover;
}

.page-about .quality-media .media-frame__img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  aspect-ratio: 10 / 7;
  object-fit: cover;
}

/* ---------- 团队卡片 ---------- */
.page-about .team-grid {
  list-style: none;
  margin: clamp(20px, 3vw, 30px) 0 0;
  padding: 0;
  display: grid;
  gap: 16px;
}

.page-about .team-card {
  padding: 18px 16px 16px;
  border: 1px solid var(--c-line);
  background: linear-gradient(180deg, rgba(233, 240, 247, 0.05), rgba(233, 240, 247, 0.012));
  box-shadow: 5px 5px 0 -1px rgba(36, 52, 74, 0.55), 10px 10px 0 -2px rgba(36, 52, 74, 0.26);
  transition: transform 0.3s var(--ease), border-color 0.3s var(--ease), box-shadow 0.3s var(--ease);
}

.page-about .team-card:hover {
  transform: translateY(-3px);
  border-color: var(--c-cyan);
  box-shadow: 5px 8px 0 -1px rgba(36, 52, 74, 0.6), 10px 14px 0 -2px rgba(36, 52, 74, 0.3);
}

.page-about .team-card__num {
  display: block;
  font-size: 22px;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--c-gold);
}

.page-about .team-card__name {
  margin: 8px 0 0;
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.03em;
  color: var(--c-paper);
}

.page-about .team-card__desc {
  margin: 8px 0 0;
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--c-steel);
}

/* ---------- 读数表 ---------- */
.page-about .spec-list {
  list-style: none;
  margin: clamp(20px, 3vw, 28px) 0 0;
  padding: 0;
  border-top: 1px solid var(--c-line);
}

.page-about .spec-list__row {
  display: grid;
  gap: 4px;
  padding: 14px 0;
  border-bottom: 1px solid var(--c-line-soft);
}

.page-about .spec-list__label {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.04em;
  color: var(--c-steel);
}

.page-about .spec-list__value {
  font-size: 15px;
  line-height: 1.6;
  color: var(--c-paper);
}

/* ---------- 认证标签 ---------- */
.page-about .cert-grid {
  margin-top: clamp(20px, 3vw, 28px);
  display: grid;
  gap: 12px;
}

.page-about .cert {
  border: 1px solid var(--c-line);
  border-left: 2px solid var(--c-gold);
  background: rgba(13, 21, 36, 0.72);
  padding: 13px 15px;
}

.page-about .cert[open] {
  border-left-color: var(--c-green);
}

.page-about .cert__summary {
  display: flex;
  align-items: center;
  gap: 10px;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.04em;
  line-height: 1.5;
  color: var(--c-paper);
  transition: color 0.25s var(--ease);
}

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

.page-about .cert__summary:hover,
.page-about .cert__summary:focus-visible {
  color: var(--c-cyan);
  outline: none;
}

.page-about .cert__summary::after {
  content: "+";
  margin-left: auto;
  color: var(--c-steel);
}

.page-about .cert[open] .cert__summary::after {
  content: "−";
  color: var(--c-cyan);
}

.page-about .cert__dot {
  flex: none;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--c-green);
  box-shadow: 0 0 10px rgba(110, 231, 168, 0.6);
}

.page-about .cert__body {
  margin: 10px 0 0;
  padding-top: 10px;
  border-top: 1px dashed var(--c-line);
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--c-steel);
}

/* ---------- 合作伙伴 ---------- */
.page-about .partner-list {
  list-style: none;
  margin: clamp(20px, 3vw, 28px) 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .partner-item {
  padding: 14px 16px;
  border: 1px solid var(--c-line);
  background: var(--c-panel);
}

.page-about .partner-item p {
  margin: 10px 0 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--c-steel);
}

/* ---------- 节奏与联系 ---------- */
.page-about .rhythm-list {
  list-style: none;
  margin: clamp(20px, 3vw, 28px) 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .rhythm-item {
  display: grid;
  gap: 4px;
  padding: 12px 0;
  border-bottom: 1px solid var(--c-line-soft);
}

.page-about .rhythm-item__cycle {
  font-size: 12.5px;
  letter-spacing: 0.06em;
  color: var(--c-gold);
}

.page-about .rhythm-item__text {
  font-size: 14px;
  line-height: 1.75;
  color: var(--c-steel);
}

.page-about .contact-slip {
  margin-top: clamp(22px, 3vw, 32px);
  padding: 18px 16px;
  border: 1px solid var(--c-line);
  border-top: 2px solid var(--c-cyan);
  background:
    radial-gradient(120% 140% at 100% 0%, var(--c-violet-soft), transparent 60%),
    var(--c-panel);
}

.page-about .contact-slip__title {
  margin: 0 0 10px;
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--c-cyan);
}

.page-about .contact-slip__line {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.9;
  color: var(--c-paper);
  word-break: break-word;
}

.page-about .contact-slip__line .mono {
  color: var(--c-cyan);
  letter-spacing: 0.02em;
}

/* ---------- 窄屏收口 ---------- */
@media (max-width: 400px) {
  .page-about .about-hero__stats {
    grid-template-columns: minmax(0, 1fr);
  }

  .page-about .chapter-index__link {
    font-size: 12.5px;
    padding: 6px 10px;
  }
}

/* ---------- 中断点 ---------- */
@media (min-width: 620px) {
  .page-about .spec-list__row {
    grid-template-columns: 210px minmax(0, 1fr);
    align-items: baseline;
    gap: 20px;
  }

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

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

  .page-about .rhythm-item {
    grid-template-columns: 168px minmax(0, 1fr);
    align-items: baseline;
    gap: 18px;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__frame {
    grid-template-columns: minmax(0, 1.12fr) minmax(0, 0.88fr);
    align-items: start;
  }

  .page-about .about-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 16px;
  }

  .page-about .chapter {
    grid-template-columns: 196px minmax(0, 1fr);
    gap: clamp(28px, 4vw, 62px);
    align-items: start;
  }

  .page-about .chapter__rail {
    position: sticky;
    top: 100px;
  }

  .page-about .chapter__body {
    max-width: 72ch;
  }

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

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

@media (min-width: 1120px) {
  .page-about .chapter__body {
    max-width: 74ch;
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .team-card,
  .page-about .chapter-index__link,
  .page-about .chapter__num,
  .page-about .inline-link,
  .page-about .cert__summary {
    transition: none;
  }

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