.page-about {
  --ab-rule: rgba(7, 17, 15, 0.14);
  --ab-rule-dark: rgba(191, 232, 223, 0.2);
  --ab-tint: #EDE8DC;
  background: var(--c-paper);
  color: var(--c-ink);
  font-family: var(--font-sans);
  font-size: var(--fs-body);
  line-height: 1.7;
  overflow-x: hidden;
}

.page-about h1,
.page-about h2,
.page-about h3 {
  margin: 0;
  font-family: var(--font-sans);
  font-weight: 800;
  letter-spacing: -0.01em;
}

.page-about p {
  margin: 0 0 16px;
}

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

.page-about a {
  color: inherit;
}

.page-about .kicker {
  margin: 0 0 16px;
}

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

.page-about .media-caption {
  margin: 12px 0 0;
  font-size: var(--fs-small);
  line-height: 1.5;
  color: rgba(7, 17, 15, 0.62);
  letter-spacing: 0.01em;
}

.page-about .media-caption--dark {
  color: var(--c-text-faint);
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  background: var(--c-deep);
  background-image:
    linear-gradient(180deg, rgba(14, 27, 42, 0) 0%, rgba(14, 27, 42, 0.55) 100%),
    repeating-linear-gradient(90deg, rgba(42, 59, 58, 0.55) 0 1px, transparent 1px 96px);
  color: var(--c-text);
  padding: 104px 0 56px;
  border-bottom: 1px solid var(--ab-rule-dark);
}

.page-about .about-hero .breadcrumb a,
.page-about .about-hero .breadcrumb li {
  color: var(--c-text-faint);
}

.page-about .about-hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 36px;
  padding-top: 28px;
}

.page-about .about-hero h1 {
  font-size: clamp(32px, 6.4vw, 60px);
  line-height: 1.06;
  letter-spacing: -0.02em;
  max-width: 15em;
  margin: 0 0 24px;
}

.page-about .about-hero-text {
  max-width: 42em;
  color: var(--c-text-dim);
  font-size: var(--fs-body);
}

.page-about .about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.page-about .about-hero-side {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 20px;
  padding-top: 8px;
  border-top: 1px solid var(--ab-rule-dark);
}

.page-about .about-hero-note {
  margin: 16px 0 0;
  font-family: var(--font-mono);
  font-size: var(--fs-tag);
  letter-spacing: 0.32em;
  line-height: 1.4;
  color: var(--c-cyan);
}

.page-about .about-hero-stats {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--ab-rule-dark);
}

.page-about .about-hero-stats li {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 16px 10px 16px 0;
  border-bottom: 1px solid var(--ab-rule-dark);
}

.page-about .stat-num {
  font-family: var(--font-mono);
  font-size: 28px;
  font-weight: 500;
  line-height: 1.1;
  letter-spacing: 0.02em;
  color: var(--c-cyan);
}

.page-about .stat-label {
  font-size: var(--fs-tag);
  letter-spacing: 0.18em;
  color: var(--c-text-faint);
}

/* ---------- 起点与定位 ---------- */

.page-about .about-origin {
  background: var(--c-night);
  color: var(--c-text);
  padding: 64px 0;
  border-bottom: 1px solid var(--ab-rule-dark);
}

.page-about .about-origin-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 36px;
}

.page-about .about-origin-media {
  min-width: 0;
}

.page-about .about-origin-body h2 {
  font-size: clamp(26px, 4.4vw, 40px);
  line-height: 1.14;
  margin: 0 0 22px;
  max-width: 14em;
}

.page-about .about-origin-body p {
  color: var(--c-text-dim);
  max-width: 46em;
}

.page-about .about-origin-body p:first-of-type {
  color: var(--c-text);
}

/* ---------- 时间线 ---------- */

.page-about .about-timeline {
  background: var(--c-paper);
  padding: 68px 0 76px;
}

.page-about .about-section-head {
  max-width: 46em;
  margin-bottom: 32px;
}

.page-about .about-section-head h2 {
  font-size: clamp(26px, 4.6vw, 44px);
  line-height: 1.12;
  margin: 0 0 16px;
}

.page-about .about-section-lead {
  color: rgba(7, 17, 15, 0.66);
  max-width: 40em;
}

.page-about .about-year-jump {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding: 14px 0;
  border-top: 1px solid var(--ab-rule);
  border-bottom: 1px solid var(--ab-rule);
  margin: 0 0 40px;
}

.page-about .about-year-jump a {
  font-family: var(--font-mono);
  font-size: var(--fs-small);
  letter-spacing: 0.14em;
  text-decoration: none;
  padding: 6px 13px;
  border: 1px solid var(--ab-rule);
  color: var(--c-ink);
  transition: background var(--ease), color var(--ease), border-color var(--ease);
}

.page-about .about-year-jump a:hover,
.page-about .about-year-jump a:focus-visible {
  background: var(--c-deep);
  border-color: var(--c-deep);
  color: var(--c-paper);
}

.page-about .about-year-jump a:focus-visible {
  outline: 2px solid var(--c-cyan);
  outline-offset: 2px;
}

.page-about .about-timeline-list {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0 0 0 28px;
}

.page-about .about-timeline-list::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 12px;
  bottom: 12px;
  width: 1px;
  background: var(--ab-rule);
}

.page-about .tl-item {
  scroll-margin-top: 120px;
  border-top: 1px solid var(--ab-rule);
}

.page-about .tl-item:last-child {
  border-bottom: 1px solid var(--ab-rule);
}

.page-about .tl-summary {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  grid-template-areas:
    "year toggle"
    "title title";
  column-gap: 16px;
  row-gap: 6px;
  align-items: start;
  padding: 22px 0;
  cursor: pointer;
  list-style: none;
  transition: background var(--ease);
}

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

.page-about .tl-summary::marker {
  content: "";
}

.page-about .tl-summary::before {
  content: "";
  position: absolute;
  left: -27px;
  top: 28px;
  width: 9px;
  height: 9px;
  background: var(--c-deep);
  transition: background var(--ease), transform var(--ease);
}

.page-about .tl-item details[open] .tl-summary::before {
  background: var(--c-cyan);
  transform: translateY(-2px);
}

.page-about .tl-summary:focus-visible {
  outline: 2px solid var(--c-deep);
  outline-offset: 4px;
}

.page-about .tl-year {
  grid-area: year;
  font-family: var(--font-mono);
  font-size: 18px;
  font-weight: 500;
  letter-spacing: 0.1em;
  line-height: 1.3;
  color: var(--c-ink);
}

.page-about .tl-title {
  grid-area: title;
  font-size: 19px;
  line-height: 1.35;
  font-weight: 700;
}

.page-about .tl-toggle {
  grid-area: toggle;
  align-self: start;
  font-family: var(--font-mono);
  font-size: var(--fs-tag);
  letter-spacing: 0.16em;
  line-height: 1.6;
  padding: 3px 10px;
  border: 1px solid var(--ab-rule);
  white-space: nowrap;
  transition: background var(--ease), color var(--ease), border-color var(--ease);
}

.page-about .tl-toggle::after {
  content: "展开";
}

.page-about .tl-item details[open] .tl-toggle::after {
  content: "收起";
}

.page-about .tl-item details[open] .tl-toggle {
  background: var(--c-deep);
  border-color: var(--c-deep);
  color: var(--c-paper);
}

.page-about .tl-summary:hover .tl-title {
  text-decoration: underline;
  text-decoration-color: var(--c-cyan);
  text-decoration-thickness: 2px;
  text-underline-offset: 5px;
}

.page-about .tl-body {
  padding: 0 0 26px;
  max-width: 60ch;
}

.page-about .tl-body p {
  color: rgba(7, 17, 15, 0.72);
}

/* ---------- 团队 ---------- */

.page-about .about-team {
  background: var(--c-night);
  color: var(--c-text);
  padding: 68px 0 76px;
  border-top: 1px solid var(--ab-rule-dark);
  border-bottom: 1px solid var(--ab-rule-dark);
}

.page-about .about-team-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 36px;
}

.page-about .about-team-media {
  min-width: 0;
}

.page-about .about-team-body h2 {
  font-size: clamp(26px, 4.6vw, 42px);
  line-height: 1.12;
  margin: 0 0 20px;
  max-width: 14em;
}

.page-about .about-team-body > p {
  color: var(--c-text-dim);
  max-width: 44em;
}

.page-about .about-team-nums {
  list-style: none;
  margin: 28px 0 24px;
  padding: 0;
  border-top: 1px solid var(--ab-rule-dark);
}

.page-about .about-team-nums li {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding: 13px 0;
  border-bottom: 1px solid var(--ab-rule-dark);
}

.page-about .team-num {
  font-family: var(--font-mono);
  font-size: 30px;
  font-weight: 500;
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--c-cyan);
}

.page-about .team-num small {
  font-size: 12px;
  letter-spacing: 0.14em;
  margin-left: 6px;
  color: var(--c-text-faint);
}

.page-about .team-label {
  font-size: var(--fs-small);
  letter-spacing: 0.16em;
  color: var(--c-text-dim);
}

.page-about .about-team-note {
  font-size: var(--fs-small);
  line-height: 1.8;
  color: var(--c-text-faint);
  max-width: 40em;
  border-left: 1px solid var(--ab-rule-dark);
  padding-left: 16px;
}

.page-about .about-team-note a {
  color: var(--c-cyan);
  text-underline-offset: 4px;
}

.page-about .about-team-note a:focus-visible {
  outline: 2px solid var(--c-cyan);
  outline-offset: 2px;
}

/* ---------- 内容把控 ---------- */

.page-about .about-quality {
  background: var(--c-paper);
  padding: 68px 0 76px;
}

.page-about .about-quality-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 36px;
}

.page-about .about-flow {
  list-style: none;
  margin: 0 0 32px;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
  border-top: 1px solid var(--ab-rule);
}

.page-about .about-flow li {
  position: relative;
  padding: 22px 0 26px;
  border-bottom: 1px solid var(--ab-rule);
}

.page-about .about-flow li::after {
  content: "↓";
  position: absolute;
  left: 0;
  bottom: -11px;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1;
  color: var(--c-deep);
  background: var(--c-paper);
  padding-right: 8px;
}

.page-about .about-flow li:last-child::after {
  content: none;
}

.page-about .flow-num {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--fs-tag);
  letter-spacing: 0.24em;
  color: var(--c-orange);
  margin-bottom: 8px;
}

.page-about .about-flow h3 {
  font-size: 20px;
  line-height: 1.3;
  margin-bottom: 8px;
}

.page-about .about-flow p {
  color: rgba(7, 17, 15, 0.7);
  max-width: 42em;
}

.page-about .about-quality-facts {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
  border-top: 1px solid var(--ab-rule);
}

.page-about .about-quality-facts li {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 4px;
  padding: 14px 0;
  border-bottom: 1px solid var(--ab-rule);
}

.page-about .fact-key {
  font-family: var(--font-mono);
  font-size: var(--fs-tag);
  letter-spacing: 0.2em;
  color: rgba(7, 17, 15, 0.5);
}

.page-about .fact-val {
  font-size: var(--fs-small);
  line-height: 1.8;
  color: var(--c-ink);
}

.page-about .about-quality-media {
  min-width: 0;
}

/* ---------- 合作与认可 ---------- */

.page-about .about-partners {
  background: var(--c-deep);
  color: var(--c-text);
  padding: 68px 0 76px;
  border-top: 1px solid var(--ab-rule-dark);
}

.page-about .about-partners .about-section-lead {
  color: var(--c-text-dim);
}

.page-about .about-partner-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
  border-top: 1px solid var(--ab-rule-dark);
}

.page-about .about-partner-list li {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  gap: 16px;
  padding: 22px 0;
  border-bottom: 1px solid var(--ab-rule-dark);
  transition: background var(--ease);
}

.page-about .about-partner-list li:hover {
  background: rgba(41, 242, 208, 0.05);
}

.page-about .partner-num {
  font-family: var(--font-mono);
  font-size: var(--fs-tag);
  letter-spacing: 0.18em;
  color: var(--c-cyan);
  padding-top: 6px;
}

.page-about .partner-body h3 {
  font-size: 19px;
  line-height: 1.35;
  margin-bottom: 8px;
  color: var(--c-text);
}

.page-about .partner-body p {
  font-size: var(--fs-small);
  line-height: 1.8;
  color: var(--c-text-dim);
  max-width: 44em;
}

/* ---------- 下一步 ---------- */

.page-about .about-contact {
  background: var(--ab-tint);
  padding: 64px 0 72px;
  border-top: 1px solid var(--ab-rule);
}

.page-about .about-contact-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 32px;
}

.page-about .about-contact-lead h2 {
  font-size: clamp(25px, 4.4vw, 40px);
  line-height: 1.14;
  margin: 0 0 18px;
  max-width: 14em;
}

.page-about .about-contact-lead p {
  color: rgba(7, 17, 15, 0.72);
  max-width: 40em;
}

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

.page-about .about-contact-card {
  background: var(--c-paper);
  border: 1px solid var(--ab-rule);
  padding: 24px 20px;
}

.page-about .about-contact-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
  border-top: 1px solid var(--ab-rule);
}

.page-about .about-contact-list li {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 4px;
  padding: 13px 0;
  border-bottom: 1px solid var(--ab-rule);
}

.page-about .contact-key {
  font-family: var(--font-mono);
  font-size: var(--fs-tag);
  letter-spacing: 0.2em;
  color: rgba(7, 17, 15, 0.5);
}

.page-about .contact-val {
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.7;
  word-break: break-word;
  color: var(--c-ink);
}

.page-about .about-contact-note {
  margin: 18px 0 0;
  font-size: var(--fs-small);
  line-height: 1.8;
  color: rgba(7, 17, 15, 0.62);
}

.page-about .about-contact-note a {
  color: var(--c-ink);
  font-weight: 700;
  text-underline-offset: 4px;
  text-decoration-color: var(--c-cyan);
  text-decoration-thickness: 2px;
}

/* ---------- 焦点反馈 ---------- */

.page-about a:focus-visible,
.page-about .tl-summary:focus-visible {
  outline: 2px solid var(--c-cyan);
  outline-offset: 3px;
}

.page-about .about-hero a:focus-visible,
.page-about .about-team a:focus-visible {
  outline: 2px solid var(--c-cyan);
  outline-offset: 3px;
}

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition-duration: 0.001ms !important;
    animation-duration: 0.001ms !important;
  }
}

/* ---------- 中等屏 ---------- */

@media (min-width: 720px) {
  .page-about .about-hero {
    padding: 120px 0 72px;
  }

  .page-about .about-tl-summary,
  .page-about .tl-summary {
    grid-template-columns: 92px minmax(0, 1fr) auto;
    grid-template-areas: "year title toggle";
    align-items: baseline;
    column-gap: 24px;
    row-gap: 0;
    padding: 24px 0;
  }

  .page-about .tl-year {
    font-size: 20px;
  }

  .page-about .tl-title {
    font-size: 21px;
  }

  .page-about .tl-summary::before {
    top: 32px;
  }

  .page-about .tl-body {
    padding-left: 116px;
  }

  .page-about .about-quality-facts li,
  .page-about .about-contact-list li {
    grid-template-columns: 128px minmax(0, 1fr);
    gap: 18px;
    align-items: baseline;
  }

  .page-about .about-partner-list li {
    grid-template-columns: 56px minmax(0, 1fr);
    gap: 24px;
    padding: 26px 0;
  }

  .page-about .about-flow li {
    padding: 24px 0 28px;
  }
}

/* ---------- 桌面 ---------- */

@media (min-width: 960px) {
  .page-about .about-hero {
    padding: 140px 0 88px;
  }

  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 56px;
    align-items: end;
    padding-top: 36px;
  }

  .page-about .about-hero-side {
    grid-template-columns: auto minmax(0, 1fr);
    gap: 28px;
    align-items: start;
    padding-top: 20px;
    border-top: 1px solid var(--ab-rule-dark);
  }

  .page-about .about-hero-note {
    writing-mode: vertical-rl;
    letter-spacing: 0.44em;
    margin: 0;
    max-height: 260px;
    padding-top: 4px;
  }

  .page-about .about-hero-stats {
    grid-template-columns: minmax(0, 1fr);
    border-top: 0;
  }

  .page-about .about-hero-stats li {
    flex-direction: row;
    align-items: baseline;
    justify-content: space-between;
    gap: 16px;
    padding: 14px 0;
  }

  .page-about .about-hero-stats li:first-child {
    border-top: 1px solid var(--ab-rule-dark);
  }

  .page-about .stat-num {
    font-size: 34px;
  }

  .page-about .about-origin {
    padding: 88px 0;
  }

  .page-about .about-origin-grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: 64px;
    align-items: center;
  }

  .page-about .about-timeline,
  .page-about .about-team,
  .page-about .about-quality,
  .page-about .about-partners {
    padding: 96px 0 104px;
  }

  .page-about .about-team-grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: 64px;
    align-items: start;
  }

  .page-about .about-team-nums {
    margin-top: 34px;
  }

  .page-about .about-quality-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 56px;
    align-items: start;
  }

  .page-about .about-flow {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    border-top: 1px solid var(--ab-rule);
    border-bottom: 1px solid var(--ab-rule);
    margin-bottom: 36px;
  }

  .page-about .about-flow li {
    padding: 24px 24px 28px 0;
    border-bottom: 0;
    border-right: 1px solid var(--ab-rule);
  }

  .page-about .about-flow li:last-child {
    border-right: 0;
    padding-right: 0;
  }

  .page-about .about-flow li::after {
    content: "→";
    left: auto;
    right: 10px;
    bottom: auto;
    top: 50%;
    transform: translateY(-50%);
    background: transparent;
    padding-right: 0;
    color: var(--c-orange);
  }

  .page-about .about-flow li:last-child::after {
    content: none;
  }

  .page-about .about-quality-facts li {
    grid-template-columns: 96px minmax(0, 1fr);
  }

  .page-about .about-contact {
    padding: 88px 0 96px;
  }

  .page-about .about-contact-grid {
    grid-template-columns: minmax(0, 6fr) minmax(0, 6fr);
    gap: 56px;
    align-items: start;
  }

  .page-about .about-contact-card {
    padding: 28px 26px;
  }
}

@media (min-width: 1200px) {
  .page-about .about-hero h1 {
    max-width: 12.5em;
  }

  .page-about .about-partner-list li {
    grid-template-columns: 64px minmax(0, 1fr);
    padding: 28px 0;
  }
}
<<<END>>>