.page-about {
  --about-edge: clamp(16px, 4.5vw, 56px);
  --about-block: clamp(48px, 7.5vw, 104px);
  --about-max: 1160px;
  background: var(--mist);
  color: var(--ink);
  font-family: var(--font-body);
  overflow-x: hidden;
}

.page-about *,
.page-about *::before,
.page-about *::after {
  box-sizing: border-box;
}

/* 面包屑 */
.page-about .breadcrumbs {
  padding: 12px var(--about-edge);
  background: var(--ink);
}

.page-about .breadcrumbs__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 12px;
  letter-spacing: 0.08em;
}

.page-about .breadcrumbs__link {
  color: var(--cold);
  text-decoration: none;
}

.page-about .breadcrumbs__link:hover,
.page-about .breadcrumbs__link:focus-visible {
  color: var(--neon);
}

.page-about .breadcrumbs__link[aria-current="page"] {
  color: var(--neon);
}

.page-about .breadcrumbs__sep {
  color: var(--rock);
}

/* 首屏 */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  display: grid;
  gap: clamp(24px, 5vw, 48px);
  padding: clamp(28px, 5.5vw, 64px) var(--about-edge) clamp(44px, 7vw, 88px);
  background: var(--ink);
  color: var(--paper);
  overflow: hidden;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  top: -14%;
  right: -12%;
  width: min(58vw, 520px);
  aspect-ratio: 1 / 1;
  background: linear-gradient(150deg, rgba(25, 227, 209, 0.22), rgba(11, 111, 105, 0) 64%);
  clip-path: polygon(20% 0, 100% 0, 80% 100%, 0 100%);
  z-index: -1;
}

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

.page-about .about-hero .kicker {
  color: var(--neon);
  margin: 0 0 14px;
}

.page-about .about-hero h1 {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(2.1rem, 7vw, 4.4rem);
  line-height: 1.04;
  letter-spacing: -0.02em;
  margin: 0 0 18px;
  max-width: 17ch;
}

.page-about .about-hero .lede {
  max-width: 52ch;
  margin: 0;
  font-size: clamp(1rem, 1.6vw, 1.0625rem);
  line-height: 1.8;
  color: rgba(248, 244, 234, 0.82);
}

.page-about .about-hero__numbers {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin-top: clamp(24px, 4vw, 36px);
}

.page-about .about-num {
  border-top: 2px solid var(--neon);
  padding-top: 10px;
}

.page-about .about-num__value {
  display: block;
  font-family: var(--font-num);
  font-weight: 700;
  font-size: clamp(1.6rem, 4.2vw, 2.2rem);
  line-height: 1;
  color: var(--paper);
}

.page-about .about-num__value small {
  font-size: 0.55em;
  color: var(--neon);
  margin-left: 2px;
}

.page-about .about-num__label {
  display: block;
  margin-top: 6px;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--cold);
}

.page-about .about-hero__figure {
  position: relative;
  margin: 0;
  z-index: 1;
}

.page-about .about-hero__figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid rgba(25, 227, 209, 0.38);
}

.page-about .about-hero__figure figcaption {
  margin-top: 10px;
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--rock);
}

/* 目录 */
.page-about .about-toc {
  position: sticky;
  top: 0;
  z-index: 6;
  background: rgba(231, 235, 232, 0.94);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--rock);
  padding: 0 var(--about-edge);
}

.page-about .about-toc .section-nav {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  scrollbar-width: none;
  padding: 10px 0;
}

.page-about .about-toc .section-nav::-webkit-scrollbar {
  display: none;
}

.page-about .about-toc .section-nav__link {
  flex: 0 0 auto;
  white-space: nowrap;
  padding: 6px 12px;
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--ink);
  text-decoration: none;
  border: 1px solid var(--rock);
  border-radius: 999px;
  transition: background 0.2s var(--ease), color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.page-about .about-toc .section-nav__link:hover,
.page-about .about-toc .section-nav__link:focus-visible {
  border-color: var(--deep-teal);
  color: var(--deep-teal);
}

.page-about .about-toc .section-nav__link[aria-current="location"] {
  background: var(--ink);
  border-color: var(--ink);
  color: var(--neon);
}

/* 章节 */
.page-about .about-block {
  position: relative;
  padding: var(--about-block) var(--about-edge);
  scroll-margin-top: 74px;
}

.page-about .about-block h2 {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.55rem, 4.2vw, 2.5rem);
  line-height: 1.16;
  letter-spacing: -0.015em;
  margin: 0 0 16px;
  max-width: 22ch;
}

.page-about .about-block p {
  margin: 0 0 14px;
  font-size: 1rem;
  line-height: 1.8;
  max-width: 64ch;
}

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

.page-about .about-block h3 {
  margin: 0 0 6px;
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.5;
}

.page-about .about-index {
  display: block;
  font-family: var(--font-num);
  font-weight: 700;
  font-size: clamp(2rem, 5.4vw, 3rem);
  line-height: 1;
  color: var(--rock);
  margin-bottom: 10px;
}

.page-about .about-head .kicker {
  color: var(--deep-teal);
}

/* 01 起点 */
.page-about #origin {
  overflow: hidden;
}

.page-about .about-contour {
  position: absolute;
  right: -8%;
  top: 10%;
  width: min(72vw, 620px);
  height: auto;
  color: var(--rock);
  opacity: 0.35;
  pointer-events: none;
  z-index: 0;
}

.page-about .about-grid {
  position: relative;
  z-index: 1;
  display: grid;
  gap: clamp(16px, 3vw, 36px);
  max-width: var(--about-max);
  margin: 0 auto;
}

.page-about .about-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 20px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-tags .tag {
  border: 2px solid var(--rock);
  border-radius: 2px;
  padding: 4px 10px;
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--ink);
  background: var(--paper);
}

.page-about .about-tags .tag--neon {
  border-color: var(--deep-teal);
  color: var(--deep-teal);
}

/* 02 团队 */
.page-about #team {
  background: var(--paper);
  border-top: 1px solid var(--rock);
  border-bottom: 1px solid var(--rock);
}

.page-about .about-row {
  display: grid;
  gap: clamp(24px, 4vw, 48px);
  max-width: var(--about-max);
  margin: 0 auto;
}

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

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--rock);
  box-shadow: 6px 6px 0 rgba(139, 150, 148, 0.28);
}

.page-about .about-figure figcaption {
  margin-top: 10px;
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--observe);
}

.page-about .roster {
  display: grid;
  gap: 12px;
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .roster__item {
  padding: 14px 16px;
  background: var(--mist);
  border: 1px solid var(--rock);
  border-left-width: 4px;
  border-radius: var(--radius);
}

.page-about .roster__item--sched {
  border-left-color: var(--neon);
}

.page-about .roster__item--proof {
  border-left-color: var(--cold);
}

.page-about .roster__item--report {
  border-left-color: var(--hot);
}

.page-about .roster__item--ux {
  border-left-color: var(--amber);
}

.page-about .roster__tag {
  display: inline-block;
  margin-bottom: 8px;
  padding: 2px 8px;
  font-size: 11px;
  letter-spacing: 0.16em;
  border: 2px solid currentColor;
  border-radius: 2px;
  color: var(--ink);
}

.page-about .roster__item--sched .roster__tag {
  color: var(--deep-teal);
}

.page-about .roster__item--proof .roster__tag {
  color: var(--observe);
}

.page-about .roster__item--report .roster__tag {
  color: var(--hot);
}

.page-about .roster__item--ux .roster__tag {
  color: #8a6110;
}

.page-about .roster__item p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.75;
}

/* 03 流程 */
.page-about .about-head {
  display: grid;
  gap: 12px;
  max-width: var(--about-max);
  margin: 0 auto clamp(24px, 4vw, 40px);
}

.page-about .about-head .about-index {
  margin-bottom: 0;
}

.page-about .flow {
  max-width: var(--about-max);
  margin: 0 auto;
  padding: 0;
  list-style: none;
  border-top: 2px solid var(--ink);
}

.page-about .flow__item {
  display: grid;
  gap: 6px;
  padding: 18px 0;
  border-bottom: 1px solid var(--rock);
}

.page-about .flow__time {
  font-family: var(--font-num);
  font-weight: 700;
  font-size: 1rem;
  letter-spacing: 0.02em;
  color: var(--deep-teal);
}

.page-about .flow__item p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--ink);
}

/* 04 覆盖 */
.page-about #network {
  background:
    linear-gradient(180deg, rgba(175, 195, 207, 0.35), rgba(231, 235, 232, 0) 40%),
    var(--mist);
}

.page-about .coverage {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin-top: 24px;
}

.page-about .coverage__item {
  padding: 14px;
  background: var(--paper);
  border: 1px solid var(--rock);
  border-radius: var(--radius);
  box-shadow: 3px 3px 0 rgba(139, 150, 148, 0.24);
}

.page-about .coverage__value {
  display: block;
  font-family: var(--font-num);
  font-weight: 700;
  font-size: clamp(1.35rem, 3.6vw, 1.75rem);
  line-height: 1;
  color: var(--ink);
}

.page-about .coverage__value small {
  font-size: 0.55em;
  color: var(--deep-teal);
  margin-left: 2px;
}

.page-about .coverage__label {
  display: block;
  margin-top: 6px;
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--observe);
}

/* 05 版本 */
.page-about .versions {
  position: relative;
  max-width: 880px;
  margin: 0 auto;
  padding: 0 0 0 24px;
  list-style: none;
}

.page-about .versions::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 10px;
  bottom: 10px;
  width: 2px;
  background: linear-gradient(var(--rock), var(--deep-teal));
}

.page-about .versions__item {
  position: relative;
  margin-bottom: 16px;
}

.page-about .versions__item::before {
  content: "";
  position: absolute;
  left: -24px;
  top: 18px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--paper);
  border: 2px solid var(--deep-teal);
}

.page-about .version {
  background: var(--paper);
  border: 1px solid var(--rock);
  border-radius: var(--radius);
  box-shadow: 3px 3px 0 rgba(139, 150, 148, 0.28);
  overflow: hidden;
  transition: box-shadow 0.2s var(--ease), border-color 0.2s var(--ease);
}

.page-about .version[open] {
  border-color: var(--deep-teal);
  box-shadow: 4px 4px 0 rgba(25, 227, 209, 0.32);
}

.page-about .version__head {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  padding: 14px 16px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .version__head::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-num);
  font-weight: 700;
  font-size: 1.125rem;
  color: var(--deep-teal);
}

.page-about .version[open] .version__head::after {
  content: "–";
}

.page-about .version__head h3 {
  margin: 0;
  font-size: 0.9375rem;
}

.page-about .version__tag {
  font-family: var(--font-num);
  font-weight: 700;
  font-size: 13px;
  padding: 2px 8px;
  border-radius: 3px;
  background: var(--ink);
  color: var(--neon);
}

.page-about .version__body {
  padding: 12px 16px 16px;
  border-top: 1px dashed var(--rock);
}

.page-about .version__body p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.75;
}

/* 06 收束 */
.page-about .about-cta {
  position: relative;
  overflow: hidden;
  background: var(--ink);
  color: var(--paper);
}

.page-about .about-cta::before {
  content: "";
  position: absolute;
  left: -10%;
  bottom: -40%;
  width: min(70vw, 560px);
  aspect-ratio: 1 / 1;
  background: linear-gradient(120deg, rgba(217, 65, 44, 0.22), rgba(11, 21, 23, 0) 68%);
  clip-path: polygon(0 0, 100% 22%, 72% 100%, 0 82%);
  pointer-events: none;
}

.page-about .about-cta__inner {
  position: relative;
  z-index: 1;
  max-width: var(--about-max);
  margin: 0 auto;
}

.page-about .about-cta .about-index {
  color: rgba(248, 244, 234, 0.42);
}

.page-about .about-cta h2 {
  color: var(--paper);
  max-width: 20ch;
}

.page-about .about-cta p {
  color: rgba(248, 244, 234, 0.84);
  max-width: 60ch;
}

.page-about .about-cta p a {
  color: var(--neon);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .about-cta p a:hover,
.page-about .about-cta p a:focus-visible {
  color: var(--paper);
}

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

.page-about .about-cta .btn--ghost {
  color: var(--paper);
  border-color: rgba(248, 244, 234, 0.5);
}

.page-about .about-cta .btn--ghost:hover,
.page-about .about-cta .btn--ghost:focus-visible {
  color: var(--neon);
  border-color: var(--neon);
}

/* 平板与桌面 */
@media (min-width: 640px) {
  .page-about .about-hero__numbers {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

@media (min-width: 860px) {
  .page-about .about-grid {
    grid-template-columns: 104px minmax(0, 1fr);
    gap: clamp(24px, 4vw, 56px);
  }

  .page-about .about-head {
    grid-template-columns: 104px minmax(0, 1fr);
    gap: clamp(24px, 4vw, 56px);
    align-items: start;
  }

  .page-about .flow__item {
    grid-template-columns: 140px minmax(0, 0.85fr) minmax(0, 1.15fr);
    align-items: baseline;
    gap: 24px;
  }

  .page-about .flow__time {
    font-size: 1.0625rem;
  }
}

@media (min-width: 960px) {
  .page-about .about-hero {
    grid-template-columns: minmax(0, 1.12fr) minmax(0, 0.88fr);
    align-items: end;
  }

  .page-about .about-hero__figure {
    transform: translateY(-24px);
  }

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

  .page-about .about-row--flip .about-figure {
    order: -1;
  }

  .page-about #origin .about-grid__main {
    padding-left: clamp(8px, 2vw, 24px);
    border-left: 1px solid var(--rock);
  }

  .page-about #team .about-figure img {
    aspect-ratio: 14 / 9;
  }
}

@media (min-width: 1180px) {
  .page-about .about-hero {
    padding-left: calc(var(--about-edge) + 8px);
    padding-right: calc(var(--about-edge) + 8px);
  }
}

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

  .page-about .version,
  .page-about .about-toc .section-nav__link {
    transition: none;
  }
}
```