.page-about {
  --about-axis: 1px;
  --about-dot: 11px;
  --about-dot-lg: 20px;
  --about-track: 22px;
  --about-on-sand: #1B211E;
  --about-sand-soft: #F2EDE1;
  color: var(--cream);
  background: var(--ink);
}

.page-about a {
  color: inherit;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: clamp(20px, 4vw, 44px) 0 clamp(28px, 5vw, 56px);
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
  background-size: 48px 48px;
  opacity: .2;
  pointer-events: none;
  -webkit-mask-image: linear-gradient(180deg, rgba(0, 0, 0, .9), transparent 88%);
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, .9), transparent 88%);
}

.page-about .about-hero > .container {
  position: relative;
  z-index: 1;
}

.page-about .breadcrumb {
  margin-bottom: clamp(20px, 3vw, 32px);
}

.page-about .about-hero__lead {
  max-width: 62ch;
  margin: 16px 0 0;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.8;
}

.page-about .about-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px 20px;
  margin: clamp(24px, 4vw, 40px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-fact {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding-left: 14px;
  border-left: 1px solid var(--line);
}

.page-about .about-fact__num {
  font-size: 24px;
  line-height: 1.1;
  letter-spacing: -.01em;
}

.page-about .about-fact__key {
  color: var(--muted);
  font-size: 12px;
  letter-spacing: .04em;
}

/* 章节索引带 */
.page-about .about-index {
  margin-top: clamp(28px, 5vw, 48px);
  border-top: 1px solid var(--line);
  padding-top: 16px;
}

.page-about .about-index__list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px 16px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-index__item a {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 6px 0;
  color: var(--muted);
  font-size: 13px;
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .14s var(--ease), border-color .14s var(--ease);
}

.page-about .about-index__item a:hover,
.page-about .about-index__item a:focus-visible,
.page-about .about-index__item a[data-active] {
  color: var(--lime);
  border-bottom-color: var(--lime);
}

.page-about .about-index__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--clay);
}

/* ---------- 通用章节 ---------- */
.page-about .about-section {
  padding: clamp(44px, 8vw, 88px) 0;
  border-top: 1px solid var(--line);
  scroll-margin-top: 72px;
}

.page-about .about-lead {
  max-width: 60ch;
  margin: 16px 0 0;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.8;
}

.page-about .about-section .title-l {
  margin-top: 12px;
  color: var(--cream);
}

/* ---------- 三层工作 ---------- */
.page-about .about-pillars {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  margin-top: clamp(28px, 4vw, 44px);
}

.page-about .pillar {
  position: relative;
  padding: 22px 20px 24px;
  background: var(--panel);
  border: 1px solid var(--line);
  transition: transform .14s var(--ease), border-color .14s var(--ease);
}

.page-about .pillar:hover {
  transform: translateY(-2px);
  border-color: var(--lime);
}

.page-about .pillar__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--clay);
}

.page-about .pillar__title {
  margin: 10px 0 8px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 19px;
  letter-spacing: -.01em;
  color: var(--cream);
}

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

/* ---------- 时间线 ---------- */
.page-about .about-section--line {
  position: relative;
  overflow: hidden;
}

.page-about .about-timeline {
  position: relative;
  margin-top: clamp(28px, 5vw, 52px);
  padding-left: var(--about-track);
}

.page-about .tl-aside {
  position: absolute;
  top: 0;
  right: -40px;
  width: 160px;
  height: 100%;
  pointer-events: none;
  opacity: .26;
}

.page-about .tl-aside img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.page-about .tl-list {
  position: relative;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .tl-list::before {
  content: "";
  position: absolute;
  top: 6px;
  bottom: 12px;
  left: 0;
  width: var(--about-axis);
  background: var(--line);
}

.page-about .tl-item {
  position: relative;
  display: grid;
  grid-template-columns: 14px minmax(0, 1fr);
  column-gap: 14px;
  padding-bottom: 20px;
}

.page-about .tl-dot {
  grid-column: 1;
  grid-row: 1;
  width: var(--about-dot);
  height: var(--about-dot);
  margin-top: 20px;
  border-radius: 50%;
  background: var(--ink);
  border: 1px solid var(--clay);
}

.page-about .tl-dot--current {
  width: var(--about-dot-lg);
  height: var(--about-dot-lg);
  margin-top: 16px;
  margin-left: -4px;
  background: var(--lime);
  border-color: var(--lime);
}

.page-about .tl-card {
  grid-column: 2;
  grid-row: 1;
  padding: 18px 18px 20px;
  background: var(--panel);
  border: 1px solid var(--line);
  transition: transform .14s var(--ease), border-color .14s var(--ease);
}

.page-about .tl-card:hover {
  transform: translateY(-2px);
  border-color: var(--lime);
}

.page-about .tl-card--current {
  background: var(--panel-soft);
  border-left: 3px solid var(--lime);
}

.page-about .tl-card__ver {
  font-size: 22px;
  letter-spacing: -.01em;
}

.page-about .tl-card__badge {
  display: inline-block;
  margin-left: 10px;
  padding: 2px 8px;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: .18em;
  color: var(--ink);
  background: var(--lime);
  vertical-align: 4px;
}

.page-about .tl-card__title {
  margin: 10px 0 8px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 18px;
  letter-spacing: -.01em;
  color: var(--cream);
}

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

.page-about .tl-details {
  margin-top: 14px;
  border-top: 1px dashed var(--line);
  padding-top: 12px;
}

.page-about .tl-details summary {
  cursor: pointer;
  list-style: none;
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--amber);
  transition: color .14s var(--ease);
}

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

.page-about .tl-details summary::before {
  content: "＋ ";
  font-family: var(--font-mono);
}

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

.page-about .tl-details summary:hover,
.page-about .tl-details summary:focus-visible {
  color: var(--lime);
}

.page-about .tl-details__list {
  margin: 10px 0 0;
  padding-left: 18px;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.8;
}

.page-about .tl-details__list li + li {
  margin-top: 6px;
}

/* ---------- 版本号查看 ---------- */
.page-about .version-check {
  padding: clamp(56px, 11vw, 128px) 0;
}

.page-about .vc-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  margin-top: clamp(28px, 4vw, 44px);
}

.page-about .vc-layer {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 22px 20px 20px;
  border: 1px solid var(--line);
}

.page-about .vc-layer--site {
  background: var(--panel);
  border-top: 3px solid var(--clay);
}

.page-about .vc-layer--desktop {
  background: var(--ink);
  border-color: var(--line);
  border-top: 3px solid var(--lime);
}

.page-about .vc-layer__tag {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--muted);
  text-transform: uppercase;
}

.page-about .vc-layer__code {
  margin: 0;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 15px;
  letter-spacing: .02em;
  color: var(--cream);
  word-break: break-word;
}

.page-about .vc-layer__code .data {
  font-size: 20px;
}

.page-about .vc-layer__code--sub {
  color: var(--muted);
  font-size: 13px;
}

.page-about .copy-btn {
  align-self: flex-start;
  margin-top: 6px;
  padding: 8px 14px;
  font-family: var(--font-body);
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--cream);
  background: transparent;
  border: 1px solid var(--line);
  cursor: pointer;
  transition: border-color .14s var(--ease), color .14s var(--ease);
}

.page-about .copy-btn:hover,
.page-about .copy-btn:focus-visible {
  border-color: var(--lime);
  color: var(--lime);
}

.page-about .copy-btn[data-copied] {
  border-color: var(--lime);
  color: var(--lime);
}

.page-about .vc-steps {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
  margin: clamp(28px, 4vw, 40px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .vc-step {
  display: grid;
  grid-template-columns: 36px minmax(0, 1fr);
  align-items: start;
  gap: 12px;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .vc-step__num {
  font-size: 14px;
  color: var(--clay);
  letter-spacing: .08em;
}

.page-about .vc-note {
  max-width: 62ch;
  margin: 22px 0 0;
  padding: 16px 18px;
  border-left: 2px solid var(--amber);
  background: rgba(242, 160, 61, .07);
  color: var(--cream);
  font-size: 13px;
  line-height: 1.8;
}

/* ---------- 生产流程 ---------- */
.page-about .flow__media {
  margin: clamp(24px, 4vw, 40px) 0 0;
}

.page-about .flow__media img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border: 1px solid var(--line);
  filter: saturate(.85) contrast(1.05);
}

.page-about .flow__media .media__cap,
.page-about .cov-side .media__cap {
  display: block;
  margin-top: 8px;
  color: var(--muted);
  font-size: 12px;
  letter-spacing: .02em;
}

.page-about .flow-steps {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  margin-top: clamp(24px, 4vw, 40px);
}

.page-about .flow-step {
  padding: 20px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-left: 2px solid var(--clay);
  transition: transform .14s var(--ease), border-color .14s var(--ease);
}

.page-about .flow-step:hover {
  transform: translateY(-2px);
  border-left-color: var(--lime);
}

.page-about .flow-step__num {
  font-size: 13px;
  letter-spacing: .12em;
}

.page-about .flow-step__title {
  margin: 8px 0 8px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 17px;
  color: var(--cream);
}

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

/* ---------- 覆盖范围 ---------- */
.page-about .coverage {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
  margin-top: clamp(24px, 4vw, 40px);
}

.page-about .cov-chart {
  display: flex;
  justify-content: center;
  padding: 8px 0;
}

.page-about .cov-svg {
  width: min(260px, 100%);
  height: auto;
  overflow: visible;
}

.page-about .cov-ring {
  opacity: .9;
}

.page-about .cov-seg circle {
  stroke-width: 10;
  opacity: .45;
  transition: opacity .14s var(--ease), stroke-width .14s var(--ease);
}

.page-about .cov-seg--lime circle { stroke: var(--lime); }
.page-about .cov-seg--amber circle { stroke: var(--amber); }
.page-about .cov-seg--clay circle { stroke: var(--clay); }

.page-about .cov-seg:hover circle {
  opacity: 1;
  stroke-width: 14;
}

.page-about .cov-svg__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 40px;
  font-weight: 700;
  fill: var(--cream);
}

.page-about .cov-svg__cap {
  font-family: var(--font-body);
  font-size: 11px;
  letter-spacing: .18em;
  fill: var(--muted);
}

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

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

.page-about .cov-text + .cov-text {
  margin-top: 16px;
}

.page-about .cov-legend {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px 14px;
  margin: 20px 0;
  padding: 0;
  list-style: none;
}

.page-about .cov-item {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 6px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .cov-num {
  font-size: 16px;
  color: var(--cream);
}

.page-about .cov-name {
  font-size: 12px;
  color: var(--muted);
  letter-spacing: .02em;
}

.page-about .cov-side {
  margin: 0;
}

.page-about .cov-side img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  border: 1px solid var(--line);
  filter: saturate(.8) contrast(1.05);
}

/* ---------- 合规与服务地区 ---------- */
.page-about .compliance {
  background: var(--sand);
  color: var(--about-on-sand);
  border-top: 1px solid var(--sand);
}

.page-about .compliance .label--dark {
  color: #6B6A5F;
}

.page-about .compliance .title-l {
  color: var(--about-on-sand);
}

.page-about .comp-lead {
  max-width: 58ch;
  margin: 16px 0 0;
  color: #4A4F48;
  font-size: 15px;
  line-height: 1.8;
}

.page-about .comp-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
  margin-top: clamp(24px, 4vw, 40px);
}

.page-about .comp-card {
  padding: 22px 20px;
  background: var(--about-sand-soft);
  border: 1px solid #D6CFBE;
}

.page-about .comp-list {
  margin: 0;
}

.page-about .comp-row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2px;
  padding: 12px 0;
  border-bottom: 1px solid #D6CFBE;
}

.page-about .comp-row:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

.page-about .comp-row:first-child {
  padding-top: 0;
}

.page-about .comp-key {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: #6B6A5F;
}

.page-about .comp-val {
  margin: 0;
  font-size: 15px;
  line-height: 1.7;
  color: var(--about-on-sand);
  word-break: break-word;
}

.page-about .comp-side {
  min-width: 0;
}

.page-about .comp-note {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: #3E443D;
}

.page-about .comp-note--sub {
  margin-top: 16px;
  font-size: 13px;
  color: #5A5F58;
}

.page-about .comp-note--sub a {
  color: #2C3A2E;
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .comp-note--sub a:hover,
.page-about .comp-note--sub a:focus-visible {
  color: #1B211E;
}

.page-about .about-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 20px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-index__list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

  .page-about .about-fact__num {
    font-size: 28px;
  }

  .page-about .vc-steps {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 20px;
  }

  .page-about .comp-row {
    grid-template-columns: 120px minmax(0, 1fr);
    align-items: baseline;
    gap: 12px;
  }
}

@media (min-width: 860px) {
  .page-about .about-pillars {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 20px;
  }

  .page-about .pillar:nth-child(2) {
    margin-top: 16px;
  }

  .page-about .flow-steps {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 16px;
  }

  .page-about .vc-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 20px;
  }

  .page-about .coverage {
    grid-template-columns: 300px minmax(0, 1fr);
    align-items: start;
    gap: 32px;
  }

  .page-about .cov-side {
    grid-column: 1 / -1;
    max-width: 560px;
  }

  .page-about .comp-grid {
    grid-template-columns: 1.1fr 1fr;
    gap: 32px;
  }

  .page-about .tl-aside {
    right: 0;
    width: 220px;
    opacity: .3;
  }
}

@media (min-width: 1024px) {
  .page-about .about-timeline {
    padding-left: 0;
  }

  .page-about .tl-list::before {
    left: 50%;
    transform: translateX(-50%);
  }

  .page-about .tl-item {
    grid-template-columns: minmax(0, 1fr) 72px minmax(0, 1fr);
    column-gap: 0;
    padding-bottom: 28px;
  }

  .page-about .tl-dot {
    grid-column: 2;
    grid-row: 1;
    justify-self: center;
    margin: 22px 0 0;
  }

  .page-about .tl-dot--current {
    margin: 17px 0 0;
  }

  .page-about .tl-card {
    grid-column: 1;
    grid-row: 1;
    margin-right: 24px;
  }

  .page-about .tl-item:nth-child(even) .tl-card {
    grid-column: 3;
    margin-right: 0;
    margin-left: 24px;
  }

  .page-about .tl-item:nth-child(odd) .tl-card {
    margin-top: 2px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .pillar,
  .page-about .tl-card,
  .page-about .flow-step,
  .page-about .cov-seg circle {
    transition: none;
  }

  .page-about .pillar:hover,
  .page-about .tl-card:hover,
  .page-about .flow-step:hover {
    transform: none;
  }
}