.page-about {
  --about-rail: 176px;
  --about-gap: 56px;
  --about-paper-ink: #1B1710;
  --about-paper-soft: rgba(27, 23, 16, .62);
  position: relative;
  background-color: var(--ink);
  background-image:
    radial-gradient(90% 55% at 88% -4%, rgba(59, 240, 220, .10), transparent 58%),
    radial-gradient(80% 50% at 2% 20%, rgba(154, 107, 255, .09), transparent 62%),
    repeating-linear-gradient(180deg, rgba(233, 240, 250, .022) 0 1px, transparent 1px 4px);
  color: var(--fog);
  font-family: var(--font-body);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-block: clamp(28px, 5vw, 62px) clamp(28px, 4vw, 50px);
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero__kicker {
  margin: 24px 0 0;
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--cyan);
}

.page-about .about-hero__title {
  margin: 14px 0 0;
  max-width: 22ch;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(30px, 5.6vw, 62px);
  line-height: 1.06;
  letter-spacing: -.012em;
  color: var(--fog);
}

.page-about .about-hero__foot {
  display: grid;
  gap: 26px;
  margin-top: clamp(20px, 3vw, 38px);
}

.page-about .about-hero__lede {
  margin: 0;
  max-width: 54ch;
  font-size: clamp(15px, 1.35vw, 18px);
  line-height: 1.85;
  color: var(--steel);
}

.page-about .about-facts {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .about-facts > div {
  background: var(--panel);
  padding: 14px 14px 16px;
}

.page-about .about-facts dt {
  font-family: var(--font-data);
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--steel);
}

.page-about .about-facts dd {
  margin: 8px 0 0;
  font-family: var(--font-data);
  font-size: clamp(15px, 1.8vw, 21px);
  font-weight: 700;
  color: var(--fog);
  font-variant-numeric: tabular-nums;
}

@media (min-width: 900px) {
  .page-about .about-hero__foot {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: start;
    gap: 48px;
  }
}

/* ---------- 主体骨架 ---------- */
.page-about .about-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
  padding-top: clamp(24px, 3.5vw, 48px);
}

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

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

/* ---------- 左侧章节导轨 ---------- */
.page-about .about-rail {
  margin-bottom: 26px;
}

.page-about .about-rail__label {
  margin: 0 0 10px;
  font-family: var(--font-data);
  font-size: 11px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--steel);
}

.page-about .about-rail__list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0 0 10px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
}

.page-about .about-rail__list::-webkit-scrollbar {
  display: none;
}

.page-about .about-rail__link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 7px 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel);
  color: var(--steel);
  text-decoration: none;
  white-space: nowrap;
  transition: color .18s var(--ease), border-color .18s var(--ease), background-color .18s var(--ease);
}

.page-about .about-rail__no {
  font-family: var(--font-data);
  font-size: 12px;
  color: var(--cyan);
}

.page-about .about-rail__name {
  font-size: 13px;
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  color: var(--fog);
  border-color: var(--cyan);
  background: var(--panel-2);
}

@media (min-width: 1000px) {
  .page-about .about-rail {
    position: sticky;
    top: 96px;
    align-self: start;
    margin-bottom: 0;
    padding-right: 10px;
    border-right: 1px solid var(--line);
  }

  .page-about .about-rail__list {
    flex-direction: column;
    gap: 1px;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .about-rail__link {
    display: grid;
    grid-template-columns: 26px minmax(0, 1fr);
    align-items: center;
    gap: 6px;
    padding: 9px 10px;
    background: transparent;
    border: 0;
    border-left: 2px solid transparent;
    border-radius: 0;
  }

  .page-about .about-rail__link:hover,
  .page-about .about-rail__link:focus-visible {
    background: rgba(59, 240, 220, .07);
    border-left-color: var(--cyan);
  }
}

/* ---------- 章节通用 ---------- */
.page-about .about-sec {
  padding-block: clamp(34px, 4.6vw, 60px);
  border-top: 1px solid var(--line);
  scroll-margin-top: 96px;
}

.page-about .about-body > .about-sec:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .about-sec__head {
  display: flex;
  align-items: baseline;
  gap: 14px;
  margin-bottom: clamp(16px, 2.4vw, 26px);
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-sec__no {
  font-family: var(--font-data);
  font-size: clamp(13px, 1.4vw, 16px);
  letter-spacing: .08em;
  color: var(--amber);
}

.page-about .about-sec__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(22px, 3.2vw, 34px);
  line-height: 1.18;
  letter-spacing: -.005em;
  color: var(--fog);
}

.page-about .about-lead {
  margin: 0 0 clamp(20px, 3vw, 30px);
  max-width: 62ch;
  font-size: 16px;
  line-height: 1.85;
  color: var(--steel);
}

/* ---------- 8 : 4 分栏 ---------- */
.page-about .about-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 26px;
}

@media (min-width: 820px) {
  .page-about .about-grid {
    grid-template-columns: minmax(0, 8fr) minmax(0, 4fr);
    gap: 40px;
    align-items: start;
  }
}

.page-about .about-prose p {
  margin: 0 0 1.1em;
  font-size: 16px;
  line-height: 1.85;
  color: var(--fog);
}

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

.page-about .about-prose strong {
  color: var(--cyan);
  font-weight: 600;
}

/* ---------- 图 ---------- */
.page-about .about-figure {
  margin: 0 0 clamp(20px, 3vw, 32px);
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel);
}

.page-about .about-figure figcaption {
  margin-top: 10px;
  font-family: var(--font-data);
  font-size: 12px;
  line-height: 1.7;
  color: var(--steel);
}

.page-about .about-figure--wide img {
  aspect-ratio: 1400 / 600;
}

/* ---------- 边注卡 ---------- */
.page-about .about-side {
  display: grid;
  gap: 16px;
  align-content: start;
}

.page-about .about-note {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 15px 16px 17px;
}

.page-about .about-note > summary {
  list-style: none;
  cursor: default;
  pointer-events: none;
  font-family: var(--font-data);
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--steel);
  text-transform: uppercase;
}

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

.page-about .about-note > summary::after {
  content: "";
  display: block;
  margin-top: 10px;
  height: 1px;
  background: var(--line);
}

.page-about .about-note__list {
  display: grid;
  gap: 8px;
  margin: 12px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-note__list li {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  padding-bottom: 8px;
  border-bottom: 1px dashed var(--line);
  font-size: 13px;
  color: var(--steel);
}

.page-about .about-note__list li:last-child {
  padding-bottom: 0;
  border-bottom: 0;
}

.page-about .about-note__v {
  font-family: var(--font-data);
  font-weight: 700;
  color: var(--fog);
  font-variant-numeric: tabular-nums;
}

@media (max-width: 719px) {
  .page-about .about-note > summary {
    pointer-events: auto;
    cursor: pointer;
  }

  .page-about .about-note > summary::after {
    display: none;
  }
}

/* ---------- 分工块 ---------- */
.page-about .about-roster {
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .about-roster__item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 2px 14px;
  align-items: baseline;
  background: var(--panel);
  padding: 14px 16px 16px;
}

.page-about .about-roster__num {
  grid-row: span 2;
  font-family: var(--font-data);
  font-size: clamp(26px, 3.4vw, 34px);
  font-weight: 700;
  line-height: 1;
  font-variant-numeric: tabular-nums;
}

.page-about .about-roster__item--cyan .about-roster__num {
  color: var(--cyan);
}

.page-about .about-roster__item--violet .about-roster__num {
  color: var(--violet);
}

.page-about .about-roster__item--amber .about-roster__num {
  color: var(--amber);
}

.page-about .about-roster__role {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 16px;
  line-height: 1.3;
  color: var(--fog);
}

.page-about .about-roster__desc {
  font-size: 13px;
  line-height: 1.65;
  color: var(--steel);
}

/* ---------- 标签组 ---------- */
.page-about .about-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding: 16px;
  background: var(--paper);
  border-radius: var(--radius);
  box-shadow: 0 12px 28px rgba(0, 0, 0, .38);
}

.page-about .about-tags__k {
  flex: 0 0 100%;
  margin: 0 0 2px;
  font-family: var(--font-data);
  font-size: 11px;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--about-paper-soft);
}

.page-about .about-tags .tag {
  background: transparent;
  border-color: rgba(27, 23, 16, .28);
  color: var(--about-paper-ink);
}

/* ---------- 工序流程 ---------- */
.page-about .about-flow {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .about-step {
  position: relative;
  background: var(--panel);
  padding: 20px 18px 22px 20px;
  border-left: 2px solid var(--line);
}

.page-about .about-step::before {
  content: "";
  position: absolute;
  top: 0;
  left: -2px;
  width: 2px;
  height: 34px;
  background: var(--cyan);
}

.page-about .about-step__time {
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--cyan);
}

.page-about .about-step__title {
  margin: 10px 0 8px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 18px;
  line-height: 1.32;
  color: var(--fog);
}

.page-about .about-step__desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--steel);
}

@media (min-width: 780px) {
  .page-about .about-flow {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ---------- 时间轴 ---------- */
.page-about .about-timeline {
  margin-top: 4px;
}

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

.page-about .about-node {
  position: relative;
  padding: 0 0 24px 26px;
  border-left: 1px solid var(--line);
}

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

.page-about .about-node__dot {
  position: absolute;
  left: -5px;
  top: 6px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--ink);
  border: 2px solid var(--amber);
}

.page-about .about-node__phase {
  font-family: var(--font-data);
  font-size: 11px;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--steel);
}

.page-about .about-node__title {
  margin: 8px 0 8px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 18px;
  line-height: 1.3;
  color: var(--fog);
}

.page-about .about-node__desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--steel);
}

@media (min-width: 920px) {
  .page-about .about-timeline__list {
    grid-auto-flow: column;
    grid-auto-columns: minmax(0, 1fr);
    border-top: 1px solid var(--line);
  }

  .page-about .about-node {
    padding: 26px 18px 0 0;
    border-left: 0;
  }

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

  .page-about .about-node__dot {
    left: 0;
    top: -5px;
    background: var(--ink);
    border-color: var(--amber);
  }

  .page-about .about-node:nth-child(3) .about-node__dot {
    border-color: var(--cyan);
  }

  .page-about .about-node:nth-child(5) .about-node__dot {
    border-color: var(--violet);
  }
}

/* ---------- 价值卡 ---------- */
.page-about .about-values {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .about-value {
  background: var(--panel);
  padding: 22px 20px 26px;
}

.page-about .about-value__idx {
  display: inline-block;
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--amber);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 2px 10px;
}

.page-about .about-value__title {
  margin: 14px 0 10px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 19px;
  line-height: 1.3;
  color: var(--fog);
}

.page-about .about-value__desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--steel);
}

@media (min-width: 760px) {
  .page-about .about-values {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

/* ---------- 收尾 ---------- */
.page-about .about-coda {
  margin-top: clamp(34px, 4.6vw, 60px);
  padding-block: clamp(28px, 4vw, 52px);
  border-top: 1px solid var(--line);
}

.page-about .about-coda__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 26px;
  align-items: center;
}

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

.page-about .about-coda__figure img {
  display: block;
  width: 100%;
  max-width: 360px;
  height: auto;
  aspect-ratio: 1 / 1;
  object-fit: cover;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel);
}

.page-about .about-coda__k {
  margin: 0;
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--cyan);
}

.page-about .about-coda__title {
  margin: 12px 0 14px;
  max-width: 24ch;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(22px, 3.4vw, 38px);
  line-height: 1.12;
  color: var(--fog);
}

.page-about .about-coda__desc {
  margin: 0 0 22px;
  max-width: 56ch;
  font-size: 16px;
  line-height: 1.85;
  color: var(--steel);
}

.page-about .about-coda__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

@media (min-width: 860px) {
  .page-about .about-coda__grid {
    grid-template-columns: minmax(0, 4fr) minmax(0, 8fr);
    gap: 44px;
  }

  .page-about .about-coda__figure img {
    max-width: 100%;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-rail__link,
  .page-about .about-note {
    transition: none;
  }
}