.page-about {
  --about-pad: clamp(18px, 5vw, 40px);
  --about-indent: 132px;
}

.page-about .about-wrap {
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 var(--about-pad) clamp(80px, 10vw, 120px);
}

.page-about a:focus-visible,
.page-about summary:focus-visible {
  outline: 2px solid var(--c-cyan);
  outline-offset: 2px;
  border-radius: 4px;
}

/* 面包屑 */
.page-about .breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding-top: clamp(20px, 4vw, 34px);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--c-muted);
}

.page-about .breadcrumbs a {
  color: var(--c-muted);
  text-decoration: none;
  transition: color 160ms var(--ease);
}

.page-about .breadcrumbs a:hover {
  color: var(--c-cyan);
}

.page-about .breadcrumbs span[aria-current="page"] {
  color: var(--c-paper);
}

/* 首屏 */
.page-about .about-hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(30px, 5vw, 56px);
  padding: clamp(34px, 6vw, 68px) 0 clamp(38px, 6vw, 72px);
  align-items: start;
}

.page-about .hero-copy .eyebrow {
  margin: 0 0 18px;
}

.page-about .hero-copy h1 {
  margin: 0;
  font-size: clamp(34px, 6.4vw, 64px);
  line-height: 1.05;
  letter-spacing: -0.02em;
  font-weight: 800;
  color: var(--c-paper);
}

.page-about .hero-lede {
  margin: clamp(18px, 3vw, 26px) 0 0;
  max-width: 34em;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--c-muted);
}

.page-about .hero-facts {
  display: flex;
  flex-wrap: wrap;
  gap: clamp(22px, 4vw, 44px);
  margin-top: clamp(26px, 4vw, 38px);
  padding-top: 22px;
  border-top: 1px solid var(--c-line);
}

.page-about .fact-num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(24px, 3.4vw, 34px);
  line-height: 1;
  color: var(--c-cyan);
  letter-spacing: -0.01em;
}

.page-about .fact-label {
  display: block;
  margin-top: 9px;
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--c-muted);
}

.page-about .hero-visual {
  position: relative;
  display: flex;
  align-items: center;
  padding: clamp(16px, 3vw, 26px);
  min-height: 220px;
  border: 1px solid var(--c-line);
  border-radius: 16px 64px 16px 16px;
  background:
    radial-gradient(circle at 88% 8%, rgba(20, 242, 200, 0.12), transparent 58%),
    linear-gradient(158deg, var(--c-surface), var(--c-ink) 74%);
  overflow: hidden;
}

.page-about .hero-visual svg {
  display: block;
  width: 100%;
  height: auto;
}

/* 章节骨架 */
.page-about .about-ch {
  padding: clamp(38px, 6vw, 66px) 0;
  border-top: 1px solid var(--c-line);
}

.page-about .ch-head {
  position: relative;
  margin-bottom: clamp(20px, 3vw, 30px);
}

.page-about .ch-num {
  display: block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 26px;
  line-height: 1;
  letter-spacing: 0.08em;
  color: var(--c-cyan);
  opacity: 0.34;
}

.page-about .ch-title {
  margin: 0;
  font-size: clamp(23px, 3.4vw, 38px);
  line-height: 1.2;
  letter-spacing: -0.015em;
  font-weight: 800;
  color: var(--c-paper);
}

.page-about .ch-body > p {
  margin: 0 0 1.15em;
  max-width: 34em;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--c-muted);
}

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

.page-about .ch-body a {
  color: var(--c-cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(20, 242, 200, 0.35);
  transition: border-color 160ms var(--ease), color 160ms var(--ease);
}

.page-about .ch-body a:hover {
  border-bottom-color: var(--c-cyan);
}

.page-about .ch-quote {
  margin: clamp(24px, 4vw, 34px) 0 0;
  padding: 6px 0 6px 20px;
  border-left: 2px solid var(--c-cyan);
  max-width: 30em;
  font-size: clamp(17px, 2.2vw, 21px);
  line-height: 1.65;
  font-weight: 600;
  color: var(--c-paper);
}

/* 图片 */
.page-about .about-figure {
  margin: clamp(28px, 5vw, 46px) 0;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  border-radius: 16px;
  object-fit: cover;
  background: var(--c-band);
}

.page-about .about-figure--narrow {
  max-width: 620px;
}

.page-about .about-figure figcaption {
  margin-top: 12px;
  font-size: 12px;
  line-height: 1.6;
  letter-spacing: 0.02em;
  color: var(--c-muted);
}

/* 五步流程 */
.page-about .flow {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  max-width: 46em;
  counter-reset: fstep;
}

.page-about .flow-step {
  position: relative;
  counter-increment: fstep;
  padding: 20px 0 20px 46px;
  border-top: 1px solid var(--c-line);
}

.page-about .flow-step::before {
  content: counter(fstep, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 21px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--c-cyan);
  opacity: 0.7;
  transition: opacity 160ms var(--ease);
}

.page-about .flow-key {
  display: block;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--c-paper);
  transition: color 160ms var(--ease);
}

.page-about .flow-text {
  margin: 7px 0 0;
  max-width: 36em;
  font-size: 14px;
  line-height: 1.78;
  color: var(--c-muted);
  transition: color 160ms var(--ease);
}

.page-about .flow-step:hover::before {
  opacity: 1;
}

.page-about .flow-step:hover .flow-key {
  color: var(--c-mist);
}

.page-about .flow-step:hover .flow-text {
  color: var(--c-paper);
}

/* 时效承诺 */
.page-about .promise {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin-top: 28px;
  max-width: 560px;
  border: 1px solid var(--c-line);
  border-radius: 14px;
  background: var(--c-line);
  overflow: hidden;
}

.page-about .promise-item {
  padding: 22px 24px;
  background: var(--c-band);
}

.page-about .promise-num {
  font-family: var(--font-mono);
  font-size: clamp(32px, 5vw, 42px);
  line-height: 1;
  color: var(--c-cyan);
}

.page-about .promise-unit {
  margin-left: 8px;
  font-size: 13px;
  color: var(--c-paper);
  letter-spacing: 0.04em;
}

.page-about .promise-label {
  margin: 12px 0 0;
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--c-muted);
}

/* 团队分工 */
.page-about .team {
  display: grid;
  gap: 24px;
  margin-top: 26px;
  max-width: 42em;
}

.page-about .team-meta {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 14px;
}

.page-about .team-name {
  font-size: 14px;
  letter-spacing: 0.01em;
  color: var(--c-paper);
}

.page-about .team-count {
  font-family: var(--font-mono);
  font-size: 22px;
  line-height: 1;
  color: var(--c-cyan);
}

.page-about .team-bar {
  margin-top: 9px;
  height: 6px;
  border-radius: 3px;
  background: var(--c-band);
  overflow: hidden;
}

.page-about .team-fill {
  display: block;
  height: 100%;
  border-radius: 3px;
  background: linear-gradient(90deg, var(--c-cyan), var(--c-mist));
}

.page-about .team-row:nth-child(1) .team-fill { width: 35.3%; }
.page-about .team-row:nth-child(2) .team-fill { width: 45.6%; }
.page-about .team-row:nth-child(3) .team-fill { width: 19.1%; }

.page-about .team-note {
  margin: 11px 0 0;
  max-width: 36em;
  font-size: 13px;
  line-height: 1.75;
  color: var(--c-muted);
}

/* 版本时间轴 */
.page-about .tl {
  position: relative;
  display: flex;
  flex-direction: column;
  margin: 26px 0 0;
}

.page-about .tl-item {
  position: relative;
  padding: 16px 0;
  border-top: 1px solid var(--c-line);
}

.page-about .tl-item > summary {
  display: flex;
  align-items: baseline;
  gap: 10px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .tl-key {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--c-gold);
}

.page-about .tl-name {
  font-size: 14.5px;
  font-weight: 600;
  color: var(--c-paper);
  transition: color 160ms var(--ease);
}

.page-about .tl-item[open] > summary .tl-name {
  color: var(--c-cyan);
}

.page-about .tl-dot {
  display: none;
}

.page-about .tl-note {
  margin: 10px 0 0;
  max-width: 32em;
  font-size: 13px;
  line-height: 1.78;
  color: var(--c-muted);
}

/* 合作 */
.page-about .partners {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px;
  margin-top: 26px;
}

.page-about .partner {
  padding: 22px 22px 24px;
  border-radius: 4px 22px 22px 22px;
  background: var(--c-band);
  border-left: 2px solid var(--c-gold);
}

.page-about .partner-num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(30px, 4.6vw, 40px);
  line-height: 1;
  color: var(--c-sand);
}

.page-about .partner-label {
  display: block;
  margin-top: 12px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--c-muted);
}

.page-about .partner-note {
  margin: 22px 0 0;
  max-width: 34em;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--c-mist);
}

/* 四件坚持 */
.page-about .creed {
  list-style: none;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 26px;
  margin: 24px 0 0;
  padding: 0;
  max-width: 52em;
}

.page-about .creed li {
  padding-left: 16px;
  border-left: 1px solid var(--c-line);
  transition: border-color 160ms var(--ease);
}

.page-about .creed li:hover {
  border-left-color: var(--c-cyan);
}

.page-about .creed-title {
  margin: 0 0 8px;
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--c-paper);
}

.page-about .creed-text {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.78;
  color: var(--c-muted);
}

/* 收尾 */
.page-about .about-cta {
  margin-top: clamp(30px, 5vw, 48px);
  padding: clamp(30px, 5vw, 52px) clamp(22px, 4vw, 48px);
  border: 1px solid var(--c-line);
  border-radius: 22px;
  background:
    radial-gradient(circle at 92% 10%, rgba(255, 176, 32, 0.1), transparent 56%),
    linear-gradient(135deg, var(--c-band), var(--c-surface) 62%);
}

.page-about .cta-title {
  margin: 0;
  font-size: clamp(22px, 3.2vw, 32px);
  line-height: 1.25;
  letter-spacing: -0.015em;
  font-weight: 800;
  color: var(--c-paper);
}

.page-about .cta-text {
  margin: 14px 0 0;
  max-width: 34em;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--c-muted);
}

.page-about .cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

/* 平板及桌面 */
@media (min-width: 640px) {
  .page-about .promise {
    grid-template-columns: 1fr 1fr;
  }

  .page-about .partners {
    grid-template-columns: 1fr 1fr;
    gap: 22px;
  }
}

@media (min-width: 860px) {
  .page-about .tl {
    flex-direction: row;
    align-items: flex-start;
  }

  .page-about .tl::before {
    content: "";
    position: absolute;
    left: 0;
    right: 0;
    top: 6px;
    height: 1px;
    background: linear-gradient(90deg, var(--c-gold), var(--c-mist));
    opacity: 0.5;
  }

  .page-about .tl-item {
    flex: 1 1 0;
    min-width: 0;
    padding: 34px 20px 0 0;
    border-top: 0;
  }

  .page-about .tl-item:last-child {
    padding-right: 0;
  }

  .page-about .tl-dot {
    display: block;
    position: absolute;
    top: 6px;
    left: 0;
    width: 11px;
    height: 11px;
    border-radius: 50%;
    background: var(--c-gold);
    box-shadow: 0 0 0 4px rgba(255, 176, 32, 0.12);
  }
}

@media (min-width: 900px) {
  .page-about .about-hero {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
  }

  .page-about .ch-head {
    display: flex;
    align-items: center;
    min-height: 96px;
    padding-left: var(--about-indent);
  }

  .page-about .ch-num {
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    margin: 0;
    font-size: 96px;
    line-height: 0.9;
    opacity: 0.16;
  }

  .page-about .ch-body {
    padding-left: var(--about-indent);
  }

  .page-about .creed {
    grid-template-columns: 1fr 1fr;
    column-gap: 44px;
    row-gap: 34px;
  }
}

@media (min-width: 1100px) {
  .page-about .hero-visual {
    min-height: 340px;
  }
}
</>