.page-about {
  --rail-w: 28px;
  --dossier-gap: clamp(1rem, 3vw, 2.25rem);
  --dossier-pad: clamp(2rem, 5.5vw, 4rem);
}

@media (min-width: 640px) {
  .page-about { --rail-w: 40px; }
}

@media (min-width: 900px) {
  .page-about { --rail-w: 52px; }
}

/* ---------- 首屏 ---------- */

.page-about .about-masthead {
  position: relative;
  padding: clamp(2rem, 6vw, 4.5rem) 0 clamp(2rem, 5vw, 3.5rem);
}

.page-about .about-masthead::before {
  content: "";
  position: absolute;
  top: 0;
  left: calc(var(--gutter) * -1);
  width: clamp(6rem, 22vw, 14rem);
  height: 3px;
  background: linear-gradient(90deg, var(--cyan-400), var(--gold-400));
  opacity: .8;
}

.page-about .about-masthead__title {
  margin: 0.6rem 0 1.1rem;
  max-width: 18ch;
}

.page-about .about-masthead__boundary {
  margin: 1.4rem 0 0;
  padding-top: 1rem;
  border-top: 1px solid var(--line-400);
  font-size: 14px;
  line-height: 1.75;
  color: var(--text-400);
  max-width: 34em;
}

.page-about .about-masthead__stamp {
  padding: clamp(1.1rem, 3vw, 1.6rem);
}

.page-about .about-stamp__caption {
  margin: 0 0 0.9rem;
  font-family: var(--font-latin);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--text-400);
}

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

.page-about .about-stamp__row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem 0.75rem;
  justify-content: space-between;
  align-items: baseline;
  padding: 0.68rem 0;
  border-top: 1px solid var(--line-400);
}

.page-about .about-stamp__row:first-child {
  border-top: 0;
}

.page-about .about-stamp dt {
  font-size: 13px;
  color: var(--text-400);
  letter-spacing: 0.04em;
}

.page-about .about-stamp dd {
  margin: 0;
  font-size: 14px;
  color: var(--text-100);
  font-variant-numeric: tabular-nums;
}

@media (min-width: 900px) {
  .page-about .about-masthead {
    display: grid;
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: clamp(1.5rem, 4vw, 3.5rem);
    align-items: end;
  }

  .page-about .about-masthead__stamp {
    margin-bottom: 0.4rem;
  }
}

/* ---------- 章节索引条 ---------- */

.page-about .about-toc {
  position: sticky;
  top: 0;
  z-index: 6;
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 0.65rem 0;
  margin-bottom: clamp(1.5rem, 4vw, 2.5rem);
  border-top: 1px solid var(--line-400);
  border-bottom: 1px solid var(--line-400);
  background: rgba(10, 18, 36, .82);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  overflow-x: auto;
  scrollbar-width: none;
}

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

.page-about .about-toc__caption {
  flex: 0 0 auto;
  margin: 0;
  font-family: var(--font-latin);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--text-400);
}

.page-about .about-toc__list {
  display: flex;
  gap: 1.25rem;
  margin: 0;
  padding: 0;
  list-style: none;
  white-space: nowrap;
}

.page-about .about-toc__link {
  display: inline-block;
  padding: 0.2rem 0;
  font-size: 13px;
  color: var(--text-400);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-toc__link:hover,
.page-about .about-toc__link:focus-visible {
  color: var(--text-100);
}

.page-about .about-toc__link[aria-current="true"] {
  color: var(--cyan-400);
  border-bottom-color: var(--cyan-400);
}

/* ---------- 档案骨架 ---------- */

.page-about .about-dossier {
  position: relative;
  padding-bottom: clamp(2rem, 6vw, 4rem);
}

@media (min-width: 720px) {
  .page-about .about-dossier::before {
    content: "";
    position: absolute;
    top: 0;
    bottom: 0;
    left: calc(var(--rail-w) / 2);
    width: 1px;
    background: linear-gradient(180deg, var(--cyan-400) 0%, var(--line-400) 22%, var(--line-400) 74%, var(--gold-400) 100%);
    opacity: .55;
  }
}

.page-about .dossier-section {
  display: grid;
  grid-template-columns: var(--rail-w) minmax(0, 1fr);
  gap: 1.25rem var(--dossier-gap);
  padding: var(--dossier-pad) 0;
  border-top: 1px solid transparent;
}

.page-about .dossier-section:first-child {
  padding-top: 0;
}

.page-about .about-spine {
  display: flex;
  justify-content: center;
  align-items: flex-start;
}

.page-about .about-spine__no {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: calc(var(--rail-w) - 6px);
  height: calc(var(--rail-w) - 6px);
  border: 1px solid var(--line-400);
  border-radius: 50%;
  background: var(--night-900);
  font-family: var(--font-latin);
  font-size: 11px;
  letter-spacing: 0.04em;
  color: var(--cyan-400);
  font-variant-numeric: tabular-nums;
}

.page-about .dossier-section__body {
  min-width: 0;
}

.page-about .dossier-title {
  margin: 0 0 1.2rem;
  font-size: clamp(1.4rem, 3.4vw, 2rem);
  line-height: 1.25;
  letter-spacing: -0.02em;
  color: var(--text-100);
}

.page-about .dossier-section__body .prose p {
  max-width: 34em;
}

/* ---------- 侧注栏 ---------- */

.page-about .about-note {
  margin: 0;
  padding-left: 0.9rem;
  border-left: 2px solid var(--cyan-400);
  font-size: 14px;
  line-height: 1.75;
  color: var(--text-400);
}

.page-about .about-note.line-app {
  border-left-color: var(--gold-400);
}

.page-about .about-note p {
  margin: 0 0 0.7rem;
}

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

.page-about .about-note__label {
  font-family: var(--font-latin);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--text-400);
}

@media (min-width: 900px) {
  .page-about .dossier-section {
    grid-template-columns: var(--rail-w) minmax(0, 7fr) minmax(0, 3fr);
  }

  .page-about .about-note {
    position: sticky;
    top: 5.5rem;
    align-self: start;
  }
}

/* ---------- 图文分栏 ---------- */

.page-about .about-split {
  display: grid;
  gap: 1.5rem;
  margin-bottom: 1.75rem;
}

.page-about .about-split .prose p {
  max-width: 34em;
}

@media (min-width: 900px) {
  .page-about .about-split {
    grid-template-columns: minmax(0, 6fr) minmax(0, 5fr);
    align-items: start;
    gap: clamp(1.5rem, 3vw, 2.5rem);
  }

  .page-about .about-split--reverse {
    grid-template-columns: minmax(0, 5fr) minmax(0, 6fr);
  }

  .page-about .about-split--reverse .about-figure {
    order: 1;
  }
}

/* ---------- 图片 ---------- */

.page-about .about-figure {
  position: relative;
  margin: 0;
  border: 1px solid var(--line-400);
  background: var(--ink-800);
  overflow: hidden;
}

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

.page-about .about-figure::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: repeating-linear-gradient(180deg, rgba(233, 239, 248, .045) 0 1px, transparent 1px 4px);
}

.page-about .about-figure--wide {
  margin-top: 1.75rem;
}

.page-about .about-figure__cap {
  padding: 0.6rem 0.8rem;
  border-top: 1px solid var(--line-400);
  font-size: 12px;
  line-height: 1.6;
  letter-spacing: 0.04em;
  color: var(--text-400);
  background: var(--ink-800);
}

@media (min-width: 900px) {
  .page-about .about-figure--wide {
    grid-column: 2 / -1;
  }
}

/* ---------- 边界双栏 ---------- */

.page-about .about-grid2 {
  display: grid;
  gap: 1rem;
}

@media (min-width: 720px) {
  .page-about .about-grid2 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1.25rem;
  }
}

.page-about .about-boundary__list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-boundary__list li {
  display: flex;
  gap: 0.7rem;
  align-items: baseline;
  padding: 0.55rem 0;
  border-top: 1px solid var(--line-400);
  font-size: 14px;
  line-height: 1.6;
  color: var(--text-100);
}

.page-about .about-boundary__list li:first-child {
  border-top: 0;
}

.page-about .about-boundary__no {
  flex: 0 0 auto;
  min-width: 1.2rem;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--cyan-400);
}

.page-about .about-boundary--out .about-boundary__no {
  color: var(--gold-400);
}

.page-about .about-boundary--out .about-boundary__list li {
  color: var(--text-400);
}

/* ---------- 编号流转示意 ---------- */

.page-about .about-flow-figure {
  margin: 1.75rem 0 0;
  padding: clamp(0.8rem, 2.5vw, 1.4rem);
  border: 1px solid var(--line-400);
  background:
    linear-gradient(180deg, rgba(53, 228, 208, .05), rgba(242, 179, 71, .04)),
    var(--ink-800);
}

.page-about .about-flow {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .about-flow__rail {
  stroke: var(--cyan-400);
  stroke-width: 1;
  opacity: .45;
}

.page-about .about-flow__rail--gold {
  stroke: var(--gold-400);
}

.page-about .about-flow__tie {
  stroke: var(--line-400);
  stroke-width: 1;
  stroke-dasharray: 3 5;
}

.page-about .about-flow__dot {
  fill: var(--night-900);
  stroke: var(--cyan-400);
  stroke-width: 1.5;
}

.page-about .about-flow__dot--gold {
  stroke: var(--gold-400);
}

.page-about .about-flow__side,
.page-about .about-flow__foot {
  font-family: var(--font-cn);
  font-size: 12px;
  fill: var(--text-400);
}

.page-about .about-flow__side {
  fill: var(--cyan-400);
}

.page-about .about-flow__side--gold {
  fill: var(--gold-400);
}

.page-about .about-flow__code {
  font-family: var(--font-latin);
  font-size: 13px;
  letter-spacing: 0.08em;
  fill: var(--text-100);
  text-anchor: middle;
  text-decoration: underline;
  text-decoration-color: var(--line-400);
}

.page-about .about-flow a:hover .about-flow__code,
.page-about .about-flow a:focus-visible .about-flow__code {
  fill: var(--cyan-400);
}

/* ---------- 编号侧注清单 ---------- */

.page-about .about-codes {
  margin: 0 0 0.8rem;
  padding: 0;
  list-style: none;
}

.page-about .about-codes li {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  align-items: baseline;
  justify-content: space-between;
  padding: 0.45rem 0.5rem;
  border-radius: var(--radius);
  border-left: 2px solid transparent;
  scroll-margin-top: 6rem;
}

.page-about .about-codes li:target {
  background: var(--glass-gold);
  border-left-color: var(--gold-400);
}

.page-about .about-codes__key {
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--text-100);
}

.page-about .about-codes__val {
  font-size: 13px;
  color: var(--text-400);
}

/* ---------- 参数表 ---------- */

.page-about .about-table-wrap {
  margin-top: 1.6rem;
  overflow-x: auto;
  border: 1px solid var(--line-400);
  background: var(--ink-700);
}

.page-about .about-table {
  width: 100%;
  min-width: 34rem;
  border-collapse: collapse;
  font-variant-numeric: tabular-nums;
}

.page-about .about-table caption {
  padding: 0.7rem 0.9rem;
  text-align: left;
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--text-400);
  border-bottom: 1px solid var(--line-400);
}

.page-about .about-table th,
.page-about .about-table td {
  padding: 0.75rem 0.9rem;
  text-align: left;
  font-size: 14px;
  line-height: 1.55;
  border-bottom: 1px solid var(--line-400);
}

.page-about .about-table th {
  font-weight: 500;
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--text-400);
}

.page-about .about-table td {
  color: var(--text-100);
}

.page-about .about-table tbody tr:last-child td {
  border-bottom: 0;
}

.page-about .about-table tbody tr {
  transition: background var(--dur) var(--ease);
}

.page-about .about-table tbody tr:hover {
  background: var(--accent-soft, rgba(53, 228, 208, .05));
}

.page-about .about-table td.num,
.page-about .about-table th.num {
  text-align: right;
  color: var(--cyan-400);
}

/* ---------- 分工列表 ---------- */

.page-about .about-roles {
  display: grid;
  gap: 0;
  margin: 1.5rem 0 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line-400);
}

.page-about .about-roles__item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  grid-template-areas:
    "count name"
    "count out";
  align-items: baseline;
  gap: 0.2rem 1rem;
  padding: 0.95rem 0;
  border-bottom: 1px solid var(--line-400);
}

.page-about .about-roles__count {
  grid-area: count;
  align-self: center;
  font-size: clamp(1.6rem, 4vw, 2.2rem);
  line-height: 1;
  color: var(--cyan-400);
  letter-spacing: -0.02em;
}

.page-about .about-roles__name {
  grid-area: name;
  font-size: 15px;
  color: var(--text-100);
}

.page-about .about-roles__out {
  grid-area: out;
  font-size: 13px;
  color: var(--text-400);
}

.page-about .about-roles__tail {
  margin-top: 1.5rem;
}

.page-about .about-roles__tail p {
  max-width: 34em;
}

/* ---------- 页尾导流 ---------- */

.page-about .about-tail {
  padding: clamp(2.5rem, 6vw, 4rem) 0 clamp(2rem, 5vw, 3rem);
  border-top: 1px solid var(--line-400);
}

.page-about .about-tail__title {
  margin: 0 0 0.8rem;
  font-size: clamp(1.25rem, 3vw, 1.7rem);
  letter-spacing: -0.01em;
  color: var(--text-100);
}

.page-about .about-tail__text {
  margin: 0 0 1.5rem;
  max-width: 34em;
  font-size: 15px;
  line-height: 1.8;
  color: var(--text-400);
}

.page-about .about-tail__links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-toc__link,
  .page-about .about-table tbody tr {
    transition: none;
  }
}
</final>