.page-about {
  --about-line: rgba(168, 179, 170, 0.22);
  --about-line-soft: rgba(168, 179, 170, 0.12);
  --about-index-w: 15.5rem;
  --about-gap: clamp(1.4rem, 3.6vw, 3rem);
  --about-pad: clamp(1rem, 2.4vw, 1.5rem);
  background: var(--fx-night);
  color: var(--fx-paper);
  counter-reset: chapter;
}

.page-about .breadcrumb {
  padding-top: clamp(1rem, 2.4vw, 1.6rem);
}

/* ---------- 首屏框景 ---------- */
.page-about .about-hero {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--about-gap);
  padding: clamp(1.6rem, 3.4vw, 2.6rem) 0 clamp(2.2rem, 5vw, 3.6rem);
  border-bottom: 1px solid var(--about-line);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 5px;
  background: repeating-linear-gradient(
    90deg,
    var(--fx-orange) 0 20px,
    transparent 20px 38px
  );
  opacity: 0.85;
}

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

.page-about .about-hero h1 {
  margin: 0.7rem 0 0;
  font-family: var(--font-serif);
  font-size: clamp(1.95rem, 5.2vw, 3.5rem);
  line-height: 1.18;
  letter-spacing: -0.01em;
  color: var(--fx-paper);
}

.page-about .about-hero .lede {
  margin: 1rem 0 0;
  max-width: 42ch;
  color: rgba(243, 239, 229, 0.82);
}

.page-about .about-hero__facts {
  display: flex;
  flex-wrap: wrap;
  gap: 0.9rem 1.9rem;
  margin: 1.7rem 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-hero__facts li {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
  border-left: 2px solid var(--fx-orange);
  padding-left: 0.7rem;
}

.page-about .about-figure {
  font-family: var(--font-mono);
  font-size: clamp(1.35rem, 3.4vw, 1.85rem);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--fx-paper);
}

.page-about .about-figure__label {
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  color: var(--fx-stone);
}

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

.page-about .media__img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .about-hero__media .media__img {
  aspect-ratio: 4 / 3;
}

.page-about .media__caption {
  margin-top: 0.55rem;
  font-size: 0.76rem;
  letter-spacing: 0.05em;
  color: var(--fx-stone);
}

/* ---------- 主体栅格 ---------- */
.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--about-gap);
  padding-top: clamp(1.6rem, 3.6vw, 2.6rem);
  padding-bottom: clamp(2.6rem, 6vw, 4.8rem);
}

.page-about .about-index {
  border: 1px solid var(--about-line);
  background: var(--fx-glass-solid);
  padding: 0.8rem;
}

.page-about .about-index__title {
  margin: 0 0 0.6rem;
  font-size: 0.7rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--fx-sand);
}

.page-about .about-index__list {
  display: flex;
  gap: 0.35rem;
  margin: 0;
  padding: 0 0 0.2rem;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-index__link {
  display: block;
  white-space: nowrap;
  padding: 0.42rem 0.7rem;
  border: 1px solid var(--about-line);
  color: var(--fx-paper);
  font-size: 0.82rem;
  text-decoration: none;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease),
    background-color var(--dur) var(--ease);
}

.page-about .about-index__link:hover {
  color: var(--fx-orange);
  border-color: var(--fx-orange);
  background: rgba(255, 90, 31, 0.08);
}

.page-about .about-index__link:focus-visible {
  outline: 2px solid var(--fx-cyan);
  outline-offset: 2px;
}

.page-about .about-index__meta {
  margin: 0.75rem 0 0;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  line-height: 1.7;
  color: var(--fx-stone);
}

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

/* ---------- 章节 ---------- */
.page-about .about-section {
  counter-increment: chapter;
  padding-top: clamp(1.6rem, 3.8vw, 2.8rem);
  scroll-margin-top: calc(var(--bar-h) + 1rem);
}

.page-about .about-section + .about-section {
  margin-top: clamp(1.6rem, 3.8vw, 2.8rem);
  border-top: 1px solid var(--about-line);
}

.page-about .about-section__head {
  display: flex;
  align-items: baseline;
  gap: 0.8rem;
}

.page-about .about-section__num {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  letter-spacing: 0.12em;
  color: var(--fx-orange);
}

.page-about .about-section__num::before {
  content: counter(chapter, decimal-leading-zero);
}

.page-about .about-section__title {
  margin: 0;
  font-family: var(--font-serif);
  font-size: clamp(1.35rem, 3.4vw, 2rem);
  line-height: 1.28;
  color: var(--fx-paper);
}

.page-about .about-section__lead {
  margin: 0.85rem 0 0;
  max-width: 46rem;
  font-size: 0.98rem;
  line-height: 1.85;
  color: rgba(243, 239, 229, 0.82);
}

.page-about .about-section__note {
  margin: 1.3rem 0 0;
  padding-left: 0.9rem;
  border-left: 2px solid var(--fx-cyan);
  font-size: 0.92rem;
  line-height: 1.85;
  color: rgba(243, 239, 229, 0.76);
}

.page-about .about-link {
  color: var(--fx-cyan);
  text-decoration: underline;
  text-decoration-color: rgba(57, 230, 210, 0.45);
  text-underline-offset: 3px;
}

.page-about .about-link:hover {
  color: var(--fx-orange);
  text-decoration-color: var(--fx-orange);
}

.page-about .about-link:focus-visible {
  outline: 2px solid var(--fx-cyan);
  outline-offset: 2px;
}

/* ---------- 双栏对照 ---------- */
.page-about .about-duo {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1rem;
  margin-top: 1.4rem;
}

.page-about .about-card {
  position: relative;
  padding: var(--about-pad);
  background: var(--fx-archive);
  border: 1px solid var(--about-line-soft);
  box-shadow: var(--shadow-panel);
}

.page-about .about-card::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 3px;
  background: var(--fx-orange);
}

.page-about .about-card--archive::before {
  background: var(--fx-sand);
}

.page-about .about-card .tag {
  display: inline-block;
  margin: 0;
}

.page-about .about-card__title {
  margin: 0.7rem 0 0.65rem;
  font-family: var(--font-serif);
  font-size: 1.15rem;
  color: var(--fx-paper);
}

.page-about .about-card__list {
  margin: 0;
  padding-left: 1.05rem;
  display: grid;
  gap: 0.55rem;
  font-size: 0.93rem;
  line-height: 1.8;
  color: rgba(243, 239, 229, 0.86);
}

.page-about .about-card__list li::marker {
  color: var(--fx-cyan);
}

.page-about .about-figures {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 0.85rem 1rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-figures__item {
  font-size: 0.78rem;
  line-height: 1.6;
  color: var(--fx-stone);
}

.page-about .about-figures__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.5rem, 4vw, 1.9rem);
  line-height: 1.05;
  letter-spacing: -0.02em;
  color: var(--fx-sand);
}

/* ---------- 流程 ---------- */
.page-about .about-process__media {
  margin-top: 1.4rem;
}

.page-about .about-process__media .media__img {
  aspect-ratio: 7 / 4;
}

.page-about .about-steps {
  list-style: none;
  margin: 1.2rem 0 0;
  padding: 0;
  display: grid;
  gap: 0.6rem;
}

.page-about .step {
  border: 1px solid var(--about-line);
  background: var(--fx-glass-solid);
}

.page-about .step summary {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.85rem 1rem;
  cursor: pointer;
  list-style: none;
  transition: background-color var(--dur) var(--ease);
}

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

.page-about .step summary:hover {
  background: rgba(255, 90, 31, 0.08);
}

.page-about .step summary:focus-visible {
  outline: 2px solid var(--fx-cyan);
  outline-offset: -2px;
}

.page-about .step summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 1.1rem;
  line-height: 1;
  color: var(--fx-orange);
}

.page-about .step[open] summary::after {
  content: "−";
}

.page-about .step__idx {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--fx-cyan);
}

.page-about .step__name {
  font-weight: 700;
  font-size: 0.95rem;
}

.page-about .step__hint {
  font-size: 0.78rem;
  color: var(--fx-stone);
}

.page-about .step__body {
  padding: 0 1rem 1rem;
  border-top: 1px solid var(--about-line-soft);
}

.page-about .step__body p {
  margin: 0.8rem 0 0;
  font-size: 0.92rem;
  line-height: 1.85;
  color: rgba(243, 239, 229, 0.82);
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  margin-top: 1.5rem;
  display: grid;
  gap: 1.2rem;
}

.page-about .about-bar {
  display: flex;
  height: 14px;
  overflow: hidden;
  border: 1px solid var(--about-line);
  background: var(--fx-night-deep);
}

.page-about .about-bar__seg {
  height: 100%;
}

.page-about .about-bar__seg--edit {
  width: 32.14%;
  background: var(--fx-orange);
}

.page-about .about-bar__seg--data {
  width: 21.43%;
  background: var(--fx-cyan);
}

.page-about .about-bar__seg--product {
  width: 17.86%;
  background: var(--fx-sand);
}

.page-about .about-bar__seg--tech {
  width: 28.57%;
  background: var(--fx-stone);
}

.page-about .about-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem 1.1rem;
  margin: 0.8rem 0 0;
  padding: 0;
  list-style: none;
  font-size: 0.78rem;
  color: var(--fx-stone);
}

.page-about .about-legend li {
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.page-about .about-dot {
  display: inline-block;
  width: 9px;
  height: 9px;
  flex: none;
}

.page-about .about-dot--edit {
  background: var(--fx-orange);
}

.page-about .about-dot--data {
  background: var(--fx-cyan);
}

.page-about .about-dot--product {
  background: var(--fx-sand);
}

.page-about .about-dot--tech {
  background: var(--fx-stone);
}

.page-about .about-roles {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0.75rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-role {
  padding: 0.95rem 1rem;
  border: 1px solid var(--about-line-soft);
  background: rgba(20, 61, 43, 0.55);
}

.page-about .about-role__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 1.7rem;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--fx-paper);
}

.page-about .about-role h3 {
  margin: 0.5rem 0 0.3rem;
  font-family: var(--font-sans);
  font-size: 0.96rem;
  color: var(--fx-paper);
}

.page-about .about-role p {
  margin: 0;
  font-size: 0.84rem;
  line-height: 1.72;
  color: var(--fx-stone);
}

.page-about .about-team__media .media__img {
  aspect-ratio: 3 / 2;
}

/* ---------- 里程碑轨道 ---------- */
.page-about .about-track {
  display: flex;
  gap: 0.8rem;
  margin-top: 1.4rem;
  padding: 0.3rem 0 1rem;
  overflow-x: auto;
  overflow-y: hidden;
  scroll-snap-type: x proximity;
  scrollbar-width: thin;
  scrollbar-color: var(--fx-orange) transparent;
}

.page-about .about-track:focus-visible {
  outline: 2px solid var(--fx-cyan);
  outline-offset: 4px;
}

.page-about .about-track::-webkit-scrollbar {
  height: 6px;
}

.page-about .about-track::-webkit-scrollbar-track {
  background: rgba(168, 179, 170, 0.14);
}

.page-about .about-track::-webkit-scrollbar-thumb {
  background: var(--fx-orange);
}

.page-about .about-node {
  flex: 0 0 min(76vw, 17rem);
  scroll-snap-align: start;
  padding: 1rem 1.05rem 1.2rem;
  border: 1px solid var(--about-line);
  background: var(--fx-glass-solid);
}

.page-about .about-node--now {
  border-color: rgba(255, 90, 31, 0.55);
  background: var(--fx-archive);
}

.page-about .about-node__ver {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 1.9rem;
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--fx-paper);
}

.page-about .about-node--now .about-node__ver {
  color: var(--fx-orange);
}

.page-about .about-node__label {
  display: inline-block;
  margin: 0.6rem 0 0.7rem;
}

.page-about .about-node__title {
  margin: 0 0 0.4rem;
  font-family: var(--font-serif);
  font-size: 1rem;
  color: var(--fx-paper);
}

.page-about .about-node__text {
  margin: 0;
  font-size: 0.85rem;
  line-height: 1.75;
  color: var(--fx-stone);
}

/* ---------- 协作网络 ---------- */
.page-about .about-network {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1rem;
  margin-top: 1.4rem;
}

.page-about .about-network__card {
  padding: 1.1rem 1.15rem 1.3rem;
  border-top: 2px solid var(--fx-sand);
}

.page-about .about-network__card .panel__title {
  font-family: var(--font-mono);
  font-size: 0.98rem;
  line-height: 1.4;
  letter-spacing: -0.01em;
  color: var(--fx-sand);
}

.page-about .about-network__text {
  margin: 0.6rem 0 0;
  font-size: 0.88rem;
  line-height: 1.8;
  color: rgba(243, 239, 229, 0.8);
}

/* ---------- 联系 ---------- */
.page-about .about-reach__panel {
  display: grid;
  gap: 1rem;
  margin-top: 1.3rem;
  padding: clamp(1.15rem, 3vw, 2rem);
  border: 1px solid var(--about-line);
  border-left: 3px solid var(--fx-orange);
  background: linear-gradient(135deg, rgba(255, 90, 31, 0.14), rgba(20, 61, 43, 0.72) 58%);
}

.page-about .about-reach__lead {
  margin: 0;
  max-width: 44rem;
  font-size: 0.95rem;
  line-height: 1.85;
  color: rgba(243, 239, 229, 0.86);
}

.page-about .about-reach__channels {
  display: grid;
  gap: 0.6rem;
}

.page-about .about-reach__channels p {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  line-height: 1.6;
  color: var(--fx-paper);
  word-break: break-word;
}

.page-about .about-reach__label {
  display: block;
  margin-bottom: 0.15rem;
  font-family: var(--font-sans);
  font-size: 0.7rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--fx-sand);
}

.page-about .about-reach__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}

/* ---------- 响应式 ---------- */
@media (min-width: 560px) {
  .page-about .about-roles {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  }

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

  .page-about .about-reach__channels p:last-child {
    grid-column: 1 / -1;
  }
}

@media (max-width: 559px) {
  .page-about .step__hint {
    display: none;
  }
}

@media (min-width: 760px) {
  .page-about .about-duo {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  }

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

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

  .page-about .about-network__card:first-child {
    grid-column: 1 / -1;
  }
}

@media (min-width: 860px) {
  .page-about .about-hero {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    align-items: center;
  }

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

@media (min-width: 1000px) {
  .page-about .about-layout {
    grid-template-columns: var(--about-index-w) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-index {
    position: sticky;
    top: calc(var(--bar-h) + 1.4rem);
  }

  .page-about .about-index__list {
    flex-direction: column;
    overflow: visible;
    gap: 0.3rem;
  }

  .page-about .about-index__link {
    white-space: normal;
  }

  .page-about .about-network {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-network__card:first-child {
    grid-column: auto;
  }
}

@media (min-width: 1240px) {
  .page-about .about-roles {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-index__link,
  .page-about .step summary {
    transition: none;
  }

  .page-about .about-track {
    scroll-behavior: auto;
  }
}
<<<END>>>