.page-about {
  --ab-hair: rgba(217, 224, 216, 0.16);
  --ab-hair-strong: rgba(217, 224, 216, 0.34);
  --ab-soft: rgba(244, 247, 242, 0.76);
  --ab-mute: rgba(244, 247, 242, 0.62);
  --ab-line-steel: rgba(91, 143, 168, 0.42);
  display: block;
  padding-bottom: 8px;
}

/* ---------- 首屏头部 ---------- */

.page-about .about-head {
  position: relative;
  padding: 32px 0 26px;
  overflow: hidden;
}

.page-about .about-head::after {
  content: "";
  position: absolute;
  top: -140px;
  right: -160px;
  width: 460px;
  height: 460px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(255, 77, 28, 0.2), rgba(255, 77, 28, 0) 68%);
  pointer-events: none;
}

.page-about .about-head .breadcrumb {
  position: relative;
  z-index: 1;
}

.page-about .about-head .eyebrow {
  position: relative;
  z-index: 1;
  margin-top: 26px;
}

.page-about .about-head h1 {
  position: relative;
  z-index: 1;
  margin: 10px 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(52px, 12vw, 96px);
  line-height: 0.92;
  letter-spacing: -0.03em;
  color: var(--mist);
}

.page-about .about-lede {
  position: relative;
  z-index: 1;
  max-width: 64ch;
  margin: 24px 0 0;
  font-size: clamp(16px, 1.7vw, 18px);
  line-height: 1.88;
  color: var(--ab-soft);
}

.page-about .about-facts {
  position: relative;
  z-index: 1;
  list-style: none;
  margin: 36px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px 18px;
}

.page-about .about-facts li {
  padding-top: 13px;
  border-top: 2px solid var(--flame);
  min-width: 0;
}

.page-about .fact-num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(26px, 5.4vw, 36px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--signal);
}

.page-about .fact-label {
  display: block;
  margin-top: 9px;
  font-size: 13px;
  line-height: 1.62;
  color: var(--stand);
}

/* ---------- 开篇通栏图 ---------- */

.page-about .about-banner {
  margin: 12px 0 0;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--ab-hair);
  background: var(--ink-2);
}

.page-about .about-banner img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

.page-about .media-caption {
  display: block;
  padding: 12px 18px 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.6;
  letter-spacing: 0.02em;
  color: var(--stand);
  background: rgba(14, 51, 43, 0.72);
}

/* ---------- 主体两栏 ---------- */

.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 36px;
  padding-top: 40px;
}

.page-about .about-index {
  display: none;
}

.page-about .index-title {
  margin: 0 0 16px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--stand);
}

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

.page-about .index-list::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(180deg, var(--flame), var(--steel) 58%, rgba(91, 143, 168, 0));
}

.page-about .index-list li {
  position: relative;
}

.page-about .index-list a {
  position: relative;
  display: block;
  padding: 7px 0 7px 22px;
  font-size: 13px;
  line-height: 1.5;
  color: var(--ab-mute);
  text-decoration: none;
  border-radius: var(--radius-sm);
  transition: color 0.2s ease, background 0.2s ease;
}

.page-about .index-list a::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 13px;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--ink);
  border: 1px solid var(--steel);
  transition: background 0.2s ease, border-color 0.2s ease;
}

.page-about .index-list a:hover,
.page-about .index-list a:focus-visible {
  color: var(--mist);
  background: rgba(91, 143, 168, 0.14);
}

.page-about .index-list a:hover::before,
.page-about .index-list a:focus-visible::before {
  background: var(--flame);
  border-color: var(--flame);
}

.page-about .index-num {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--stand);
  margin-right: 8px;
}

/* ---------- 章节 ---------- */

.page-about .about-articles {
  display: flex;
  flex-direction: column;
  gap: 62px;
  min-width: 0;
}

.page-about .about-section {
  scroll-margin-top: 124px;
  min-width: 0;
}

.page-about .about-kicker {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--flame);
}

.page-about .about-kicker--dark {
  color: var(--flame-deep);
}

.page-about .about-title {
  margin: 0 0 20px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(28px, 5.4vw, 46px);
  line-height: 1.08;
  letter-spacing: -0.015em;
  color: var(--mist);
}

.page-about .about-text {
  max-width: 68ch;
  font-size: 16.5px;
  line-height: 1.92;
  color: var(--ab-soft);
}

.page-about .about-text p {
  margin: 0 0 1.05em;
}

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

.page-about .about-text a {
  color: var(--signal);
  text-decoration: none;
  border-bottom: 1px solid rgba(232, 255, 58, 0.4);
  transition: border-color 0.2s ease, color 0.2s ease;
}

.page-about .about-text a:hover,
.page-about .about-text a:focus-visible {
  color: var(--mist);
  border-bottom-color: var(--mist);
}

/* ---------- 浅色数据区 ---------- */

.page-about .about-section--light {
  padding: 30px 22px 34px;
  border-radius: var(--radius-lg);
  background: var(--mist);
  color: var(--ink);
}

.page-about .about-section--light .about-title {
  color: var(--ink);
}

.page-about .about-section--light .about-text {
  color: rgba(7, 31, 26, 0.78);
}

.page-about .about-section--light .about-text a {
  color: var(--flame-deep);
  border-bottom-color: rgba(179, 42, 15, 0.4);
}

.page-about .about-section--light .about-text a:hover,
.page-about .about-section--light .about-text a:focus-visible {
  color: var(--ink);
  border-bottom-color: var(--ink);
}

.page-about .about-section--light .media-caption {
  background: rgba(217, 224, 216, 0.7);
  color: var(--stand);
}

/* ---------- 角色卡片 ---------- */

.page-about .role-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin: 26px 0 0;
}

.page-about .role-card {
  padding: 22px 20px 24px;
  border-radius: var(--radius-md);
  background: linear-gradient(158deg, rgba(29, 90, 74, 0.34), rgba(14, 51, 43, 0.72));
  border: 1px solid var(--ab-hair);
}

.page-about .role-card h3 {
  margin: 14px 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 19px;
  line-height: 1.3;
  letter-spacing: 0.01em;
  color: var(--mist);
}

.page-about .role-card p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--ab-soft);
}

.page-about .about-section--light .role-card {
  background: rgba(255, 255, 255, 0.76);
  border-color: rgba(7, 31, 26, 0.1);
}

.page-about .about-section--light .role-card h3 {
  color: var(--ink);
}

.page-about .about-section--light .role-card p {
  color: rgba(7, 31, 26, 0.74);
}

.page-about .about-section--light .tag {
  color: var(--flame-deep);
}

.page-about .about-section--light .tag--signal {
  color: #4a5a00;
}

/* ---------- 图片 ---------- */

.page-about .about-figure {
  margin: 30px 0 0;
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--ab-hair);
  background: var(--ink-2);
}

.page-about .about-section--light .about-figure {
  border-color: rgba(7, 31, 26, 0.12);
  background: var(--paper);
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
}

/* ---------- 流程路径 ---------- */

.page-about .flow-path {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
}

.page-about .flow-step {
  position: relative;
  margin-left: 6px;
  padding: 0 0 24px 28px;
  border-left: 1px solid var(--ab-line-steel);
}

.page-about .about-section--light .flow-step {
  border-left-color: rgba(91, 143, 168, 0.6);
}

.page-about .flow-step:last-child {
  border-left-color: transparent;
  padding-bottom: 0;
}

.page-about .flow-step::before {
  content: "";
  position: absolute;
  left: -5px;
  top: 6px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--flame);
  box-shadow: 0 0 0 3px rgba(255, 77, 28, 0.16);
}

.page-about .flow-step:last-child::before {
  background: var(--signal);
  box-shadow: 0 0 0 3px rgba(232, 255, 58, 0.16);
}

.page-about .flow-label {
  display: block;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 17px;
  letter-spacing: 0.01em;
  color: var(--mist);
}

.page-about .about-section--light .flow-label {
  color: var(--ink);
}

.page-about .flow-note {
  display: block;
  margin-top: 5px;
  max-width: 56ch;
  font-size: 14.5px;
  line-height: 1.76;
  color: var(--ab-mute);
}

.page-about .about-section--light .flow-note {
  color: rgba(7, 31, 26, 0.68);
}

/* ---------- 引文块 ---------- */

.page-about .about-quote {
  margin: 30px 0 0;
  padding: 4px 0 4px 22px;
  border-left: 4px solid var(--flame);
  font-size: clamp(18px, 3.4vw, 23px);
  line-height: 1.78;
  font-weight: 500;
  color: var(--mist);
  max-width: 46ch;
}

.page-about .about-quote + .about-text {
  margin-top: 28px;
}

/* ---------- 服务条目 ---------- */

.page-about .scope-list {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 2px;
}

.page-about .scope-list li {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 4px;
  padding: 16px 0;
  border-top: 1px solid var(--ab-hair);
}

.page-about .scope-list li:last-child {
  border-bottom: 1px solid var(--ab-hair);
}

.page-about .scope-key {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--steel);
}

.page-about .scope-val {
  font-size: 15.5px;
  line-height: 1.82;
  color: var(--ab-soft);
}

/* ---------- 时间线 ---------- */

.page-about .timeline {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
}

.page-about .milestone {
  position: relative;
  margin-left: 6px;
  padding: 0 0 30px 26px;
  border-left: 1px solid var(--ab-line-steel);
  scroll-margin-top: 124px;
}

.page-about .milestone:last-child {
  border-left-color: transparent;
  padding-bottom: 0;
}

.page-about .milestone::before {
  content: "";
  position: absolute;
  left: -5px;
  top: 7px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--flame);
  box-shadow: 0 0 0 3px rgba(255, 77, 28, 0.16);
  transition: background 0.2s ease, box-shadow 0.2s ease;
}

.page-about .milestone:hover::before {
  background: var(--signal);
  box-shadow: 0 0 0 4px rgba(232, 255, 58, 0.18);
}

.page-about .milestone-stage {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--signal);
}

.page-about .milestone h3 {
  margin: 8px 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(19px, 3.2vw, 24px);
  line-height: 1.3;
  color: var(--mist);
}

.page-about .milestone > p {
  margin: 0;
  max-width: 62ch;
  font-size: 15.5px;
  line-height: 1.86;
  color: var(--ab-soft);
}

/* ---------- 展开组 ---------- */

.page-about .disclosure-trigger {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: 12px;
  padding: 7px 15px;
  border: 1px solid var(--ab-hair-strong);
  border-radius: var(--pill);
  background: transparent;
  color: var(--ab-mute);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  cursor: pointer;
  transition: border-color 0.2s ease, color 0.2s ease, background 0.2s ease;
}

.page-about .disclosure-trigger:hover,
.page-about .disclosure-trigger:focus-visible {
  border-color: var(--flame);
  color: var(--mist);
  background: rgba(255, 77, 28, 0.1);
}

.page-about .disclosure-trigger[aria-expanded="true"] {
  border-color: var(--flame);
  color: var(--signal);
  background: rgba(255, 77, 28, 0.14);
}

.page-about .disclosure-icon {
  position: relative;
  flex: none;
  width: 10px;
  height: 10px;
}

.page-about .disclosure-icon::before,
.page-about .disclosure-icon::after {
  content: "";
  position: absolute;
  background: currentColor;
}

.page-about .disclosure-icon::before {
  left: 0;
  top: 4.5px;
  width: 10px;
  height: 1px;
}

.page-about .disclosure-icon::after {
  left: 4.5px;
  top: 0;
  width: 1px;
  height: 10px;
  transition: transform 0.2s ease;
}

.page-about .disclosure-trigger[aria-expanded="true"] .disclosure-icon::after {
  transform: scaleY(0);
}

.page-about .disclosure-panel {
  margin-top: 14px;
  padding: 16px 18px;
  border-radius: var(--radius-md);
  border-left: 3px solid var(--steel);
  background: rgba(29, 90, 74, 0.3);
  font-size: 14.5px;
  line-height: 1.84;
  color: var(--ab-soft);
  max-width: 62ch;
}

.page-about .disclosure-panel[hidden] {
  display: none;
}

.page-about .disclosure-panel p {
  margin: 0;
}

/* ---------- 结尾行动区 ---------- */

.page-about .about-cta {
  padding: 30px 22px 32px;
  border-radius: var(--radius-lg);
  background: linear-gradient(140deg, rgba(255, 77, 28, 0.2), rgba(14, 51, 43, 0.94) 62%);
  border: 1px solid rgba(255, 77, 28, 0.3);
}

.page-about .about-cta h2 {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(24px, 4.6vw, 34px);
  line-height: 1.14;
  letter-spacing: -0.01em;
  color: var(--mist);
}

.page-about .about-cta p {
  margin: 0;
  max-width: 60ch;
  font-size: 15.5px;
  line-height: 1.86;
  color: var(--ab-soft);
}

.page-about .about-cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 22px;
}

/* ---------- 响应式 ---------- */

@media (min-width: 620px) {
  .page-about .role-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 768px) {
  .page-about .about-head {
    padding: 54px 0 34px;
  }

  .page-about .about-section--light {
    padding: 38px 34px 42px;
  }

  .page-about .about-cta {
    padding: 40px 38px 42px;
  }

  .page-about .scope-list li {
    grid-template-columns: 132px minmax(0, 1fr);
    gap: 20px;
    align-items: baseline;
  }

  .page-about .scope-key {
    padding-top: 3px;
  }
}

@media (min-width: 900px) {
  .page-about .role-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 22px;
  }
}

@media (min-width: 1080px) {
  .page-about .about-body {
    grid-template-columns: 176px minmax(0, 1fr);
    gap: 60px;
    padding-top: 56px;
  }

  .page-about .about-index {
    display: block;
    position: sticky;
    top: 132px;
    align-self: start;
  }

  .page-about .about-articles {
    gap: 76px;
  }

  .page-about .about-quote {
    margin-left: 4px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .index-list a,
  .page-about .disclosure-trigger,
  .page-about .disclosure-icon::after,
  .page-about .milestone::before,
  .page-about .about-text a {
    transition: none;
  }
}
</main>