.page-about {
  --ab-line: #E7DFC9;
  --ab-gold-line: rgba(201, 162, 39, .42);
  --ab-gap: 20px;
}

/* ============ 面包屑 ============ */
.page-about .about-crumbs {
  padding-top: 20px;
  padding-bottom: 4px;
}

/* ============ 封面 ============ */
.page-about .about-cover {
  position: relative;
  overflow: hidden;
  background: var(--deep);
  color: var(--white);
  padding: 34px 0 44px;
}

.page-about .about-cover::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    repeating-linear-gradient(90deg, rgba(201, 162, 39, .085) 0 1px, transparent 1px 72px),
    repeating-linear-gradient(0deg, rgba(201, 162, 39, .085) 0 1px, transparent 1px 72px);
  pointer-events: none;
}

.page-about .about-cover::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--gold), rgba(201, 162, 39, .16) 62%, transparent);
}

.page-about .about-cover__grid {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 30px;
}

.page-about .about-cover__kicker {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .22em;
  color: var(--gold);
}

.page-about .about-cover h1 {
  margin: 14px 0 0;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(29px, 6.4vw, 52px);
  line-height: 1.2;
  letter-spacing: -.02em;
  color: var(--white);
}

.page-about .about-cover__lead {
  margin: 18px 0 0;
  max-width: 58ch;
  font-size: 16px;
  line-height: 1.85;
  color: rgba(255, 253, 247, .82);
}

.page-about .about-cover__facts {
  list-style: none;
  margin: 26px 0 0;
  padding: 1px;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--ab-gold-line);
  border: 1px solid var(--ab-gold-line);
}

.page-about .about-cover__facts li {
  background: var(--deep);
  padding: 12px 12px 13px;
}

.page-about .about-cover__num {
  display: block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 25px;
  line-height: 1.1;
  letter-spacing: -.01em;
  color: var(--gold);
}

.page-about .about-cover__unit {
  display: block;
  margin-top: 5px;
  font-size: 12px;
  letter-spacing: .04em;
  color: rgba(255, 253, 247, .62);
}

.page-about .about-cover__figure {
  margin: 0;
  padding: 9px;
  border: 1px solid var(--ab-gold-line);
  background: rgba(255, 253, 247, .04);
}

/* ============ 图片容器 ============ */
.page-about .about-shot {
  display: block;
  overflow: hidden;
  background: #22352E;
}

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

.page-about .about-shot__cap {
  display: block;
  margin-top: 10px;
  font-size: 12px;
  line-height: 1.65;
  letter-spacing: .03em;
  color: var(--muted);
}

.page-about .about-cover__figure .about-shot__cap {
  color: rgba(255, 253, 247, .56);
}

/* ============ 主体栅格 ============ */
.page-about .about-body {
  display: grid;
  gap: 26px;
  padding-top: 30px;
  padding-bottom: 56px;
}

/* ============ 左侧章节轨道 ============ */
.page-about .about-rail {
  position: relative;
}

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

.page-about .about-rail__nav {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
}

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

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

.page-about .about-rail__list a {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  white-space: nowrap;
  padding: 8px 13px;
  border: 1px solid var(--ab-line);
  background: var(--white);
  color: var(--deep);
  font-size: 13px;
  text-decoration: none;
  transition: background .25s var(--ease), border-color .25s var(--ease);
}

.page-about .about-rail__idx {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--gold);
}

.page-about .about-rail__list a[aria-current],
.page-about .about-rail__list a.is-on {
  background: var(--pale);
  border-color: var(--gold);
  color: var(--deep);
}

/* ============ 面板堆叠 ============ */
.page-about .about-sections {
  display: flex;
  flex-direction: column;
  gap: 24px;
  min-width: 0;
}

.page-about .about-panel {
  position: relative;
  background: var(--white);
  border: 1px solid var(--ab-line);
  border-top: 3px solid var(--gold);
  box-shadow: var(--shadow-layer);
  padding: 26px 20px 22px;
}

.page-about .about-panel__head {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding-bottom: 14px;
  margin-bottom: 20px;
  border-bottom: 1px solid var(--ab-line);
}

.page-about .about-panel__head .rule-num {
  flex: none;
}

.page-about .about-panel__kicker {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .2em;
  color: var(--mid);
}

.page-about .about-panel__title {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(21px, 3.6vw, 28px);
  line-height: 1.38;
  letter-spacing: -.01em;
  color: var(--deep);
}

.page-about .about-panel__body p {
  margin: 0 0 16px;
  font-size: 16px;
  line-height: 1.85;
  color: var(--ink);
}

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

.page-about .about-subhead {
  margin-top: 24px !important;
  font-size: 14px !important;
  letter-spacing: .02em;
  color: var(--muted) !important;
}

/* ============ 深墨绿面板 ============ */
.page-about .about-panel--ink {
  background: var(--deep);
  border-color: rgba(201, 162, 39, .35);
  border-top-color: var(--gold);
}

.page-about .about-panel--ink .about-panel__head {
  border-bottom-color: rgba(201, 162, 39, .32);
}

.page-about .about-panel--ink .about-panel__kicker {
  color: var(--gold);
}

.page-about .about-panel--ink .about-panel__title {
  color: var(--white);
}

.page-about .about-panel--ink .about-panel__body p {
  color: rgba(255, 253, 247, .84);
}

.page-about .about-panel--ink .about-shot {
  background: rgba(255, 253, 247, .06);
}

.page-about .about-panel--ink .about-shot__cap {
  color: rgba(255, 253, 247, .56);
}

.page-about .about-panel--ink .about-fields li:nth-child(odd) {
  background: rgba(201, 162, 39, .08);
}

.page-about .about-panel--ink .about-fields__k {
  color: var(--gold);
}

.page-about .about-panel--ink .about-fields__v {
  color: rgba(255, 253, 247, .74);
}

/* ============ 数字索引 ============ */
.page-about .about-stats {
  list-style: none;
  margin: 22px 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.page-about .about-stat {
  background: rgba(201, 162, 39, .1);
  border: 1px solid rgba(201, 162, 39, .4);
  padding: 14px 12px 13px;
}

.page-about .about-stat__num {
  display: block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(26px, 5.4vw, 38px);
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--gold);
}

.page-about .about-stat__label {
  display: block;
  margin-top: 8px;
  font-size: 12px;
  line-height: 1.5;
  letter-spacing: .04em;
  color: rgba(255, 253, 247, .68);
}

/* ============ 字段清单 ============ */
.page-about .about-fields {
  list-style: none;
  margin: 20px 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
}

.page-about .about-fields li {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 11px 13px;
  border-bottom: 1px solid rgba(201, 162, 39, .22);
  font-size: 14px;
}

.page-about .about-fields li:nth-child(odd) {
  background: rgba(231, 223, 201, .3);
}

.page-about .about-fields__k {
  flex: none;
  width: 5.4em;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--deep);
}

.page-about .about-fields__v {
  color: var(--muted);
  line-height: 1.7;
}

/* ============ 图片块 ============ */
.page-about .about-figure {
  margin: 24px 0;
}

/* ============ 三组分工 ============ */
.page-about .about-crews {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
  margin: 22px 0 4px;
}

.page-about .about-crew {
  position: relative;
  background: var(--paper);
  border: 1px solid var(--ab-line);
  border-left: 3px solid var(--deep);
  padding: 16px 15px 17px;
}

.page-about .about-crew__idx {
  display: block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .2em;
  color: var(--gold);
}

.page-about .about-crew__name {
  margin: 7px 0 8px;
  font-family: var(--font-head);
  font-size: 16px;
  font-weight: 700;
  letter-spacing: .01em;
  color: var(--deep);
}

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

/* ============ 编号步骤 ============ */
.page-about .about-steps {
  margin: 16px 0 22px;
  padding: 0 0 0 0;
  list-style: none;
  counter-reset: abstep;
}

.page-about .about-steps li {
  position: relative;
  counter-increment: abstep;
  padding: 12px 0 12px 44px;
  border-bottom: 1px dashed var(--ab-line);
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink);
}

.page-about .about-steps li::before {
  content: counter(abstep, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 13px;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--red);
}

.page-about .about-steps strong {
  color: var(--deep);
  font-weight: 700;
}

/* ============ 时间线 ============ */
.page-about .about-timeline {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  position: relative;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 14px;
  width: 1px;
  background: linear-gradient(180deg, var(--gold), rgba(201, 162, 39, .12));
}

.page-about .about-timeline__item {
  position: relative;
  padding: 0 0 22px 30px;
}

.page-about .about-timeline__item:last-child {
  padding-bottom: 0;
}

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 5px;
  width: 15px;
  height: 15px;
  border-radius: 50%;
  background: var(--paper);
  border: 2px solid var(--gold);
}

.page-about .about-timeline__when {
  display: inline-block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--red);
}

.page-about .about-timeline__what h3 {
  margin: 6px 0 6px;
  font-family: var(--font-head);
  font-size: 16px;
  font-weight: 700;
  color: var(--deep);
}

.page-about .about-timeline__what p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
}

/* ============ 行动链接 ============ */
.page-about .about-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 24px 0 0 !important;
}

/* ============ 脚注 ============ */
.page-about .about-foot {
  margin-top: 22px;
  padding-top: 12px;
  border-top: 1px dashed var(--ab-line);
  font-size: 13px;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .about-foot summary {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--mid);
}

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

.page-about .about-foot summary::before {
  content: "＋";
  font-size: 12px;
  color: var(--gold);
}

.page-about .about-foot[open] summary::before {
  content: "－";
}

.page-about .about-foot p {
  margin: 10px 0 0;
  font-size: 13px;
  line-height: 1.8;
  color: inherit;
}

.page-about .about-panel--ink .about-foot {
  border-top-color: rgba(201, 162, 39, .28);
  color: rgba(255, 253, 247, .6);
}

.page-about .about-panel--ink .about-foot summary {
  color: var(--gold);
}

/* ============ 平板及以上 ============ */
@media (min-width: 620px) {
  .page-about .about-cover__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

  .page-about .about-fields li:nth-child(odd) {
    background: transparent;
  }

  .page-about .about-fields li:nth-child(4n + 1),
  .page-about .about-fields li:nth-child(4n + 2) {
    background: rgba(231, 223, 201, .3);
  }

  .page-about .about-panel--ink .about-fields li:nth-child(odd) {
    background: transparent;
  }

  .page-about .about-panel--ink .about-fields li:nth-child(4n + 1),
  .page-about .about-panel--ink .about-fields li:nth-child(4n + 2) {
    background: rgba(201, 162, 39, .08);
  }

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

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

  .page-about .about-panel {
    padding: 32px 30px 26px;
  }
}

/* ============ 桌面端：左侧轨道 + 错位面板 ============ */
@media (min-width: 900px) {
  .page-about .about-body {
    grid-template-columns: 216px minmax(0, 1fr);
    gap: 52px;
    padding-top: 44px;
    padding-bottom: 80px;
  }

  .page-about .about-rail {
    position: sticky;
    top: 112px;
    padding-left: 44px;
  }

  .page-about .about-rail__spine {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 18px;
    position: absolute;
    left: 0;
    top: 0;
    width: 32px;
    padding: 2px 0 2px;
    border-right: 1px solid var(--ab-gold-line);
  }

  .page-about .about-rail__year {
    writing-mode: vertical-rl;
    text-orientation: mixed;
    font-family: var(--font-mono);
    font-variant-numeric: tabular-nums;
    font-size: 11px;
    letter-spacing: .3em;
    color: var(--muted);
  }

  .page-about .about-rail__nav {
    overflow: visible;
  }

  .page-about .about-rail__list {
    display: block;
    padding: 0;
  }

  .page-about .about-rail__list li {
    margin-bottom: 2px;
  }

  .page-about .about-rail__list a {
    display: flex;
    width: 100%;
    padding: 9px 10px;
    border: 0;
    border-left: 2px solid transparent;
    background: transparent;
    font-size: 13.5px;
    line-height: 1.5;
  }

  .page-about .about-rail__list a:hover {
    background: rgba(231, 223, 201, .45);
  }

  .page-about .about-panel__head {
    gap: 20px;
  }

  .page-about .about-sections {
    gap: 34px;
  }

  .page-about .about-sections > .about-panel:nth-child(2) {
    margin-left: 34px;
  }

  .page-about .about-sections > .about-panel:nth-child(4) {
    margin-left: 58px;
  }

  .page-about .about-sections > .about-panel:nth-child(5) {
    margin-left: 18px;
  }
}

@media (min-width: 1100px) {
  .page-about .about-cover {
    padding: 52px 0 62px;
  }

  .page-about .about-cover__grid {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, .92fr);
    gap: 54px;
    align-items: center;
  }

  .page-about .about-cover__lead {
    font-size: 17px;
  }
}

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