.page-about {
  --pa-pad: clamp(1.25rem, 4.5vw, 3.75rem);
  --pa-sec-gap: clamp(2rem, 5vw, 4rem);
  background: var(--paper);
  color: var(--text);
  font-family: var(--font-body);
  overflow-x: hidden;
}

.page-about .pa-frame {
  max-width: var(--wide);
  margin: 0 auto;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
}

.page-about .pa-flow {
  min-width: 0;
  display: flex;
  flex-direction: column;
}

/* ---------- 面板与色区 ---------- */

.page-about .panel {
  padding: var(--pa-sec-gap) var(--pa-pad);
  position: relative;
}

.page-about .panel--ink {
  background: var(--deep);
  color: var(--text-inv);
}

.page-about .panel--teal {
  background: var(--teal);
  color: var(--text-inv);
}

.page-about .panel--indigo {
  background: var(--indigo);
  color: var(--text-inv);
}

.page-about .panel--wine {
  background: var(--wine);
  color: var(--text-inv);
}

.page-about .panel--blue {
  background: var(--blue);
  color: var(--text-inv);
}

.page-about .panel--paper {
  background: #FFFFFF;
  color: var(--text);
  border-top: 1px solid var(--line);
}

/* ---------- 首屏 ---------- */

.page-about .pa-hero {
  padding: 0;
  overflow: hidden;
}

.page-about .pa-hero::before {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  width: 58%;
  background: var(--blue);
  clip-path: polygon(30% 0, 100% 0, 100% 100%, 0 100%);
  pointer-events: none;
}

.page-about .pa-hero::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  width: 32%;
  background: var(--blue-light);
  opacity: .32;
  clip-path: polygon(44% 0, 100% 0, 100% 100%, 0 100%);
  pointer-events: none;
}

.page-about .pa-hero-inner {
  position: relative;
  z-index: 1;
  padding: clamp(2.25rem, 6vw, 4.5rem) var(--pa-pad);
}

.page-about .pa-hero-main {
  max-width: 48rem;
}

.page-about .pa-crumbs {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem;
  align-items: center;
  margin: 0 0 clamp(1.25rem, 3vw, 2rem);
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .18em;
  color: rgba(247, 248, 250, .6);
}

.page-about .pa-crumbs a {
  color: var(--text-inv);
  text-decoration: none;
  border-bottom: 1px solid rgba(247, 248, 250, .38);
  padding-bottom: 2px;
}

.page-about .pa-crumbs a:hover,
.page-about .pa-crumbs a:focus-visible {
  border-bottom-color: var(--signal);
}

.page-about .pa-hero-title {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.85rem, 5.6vw, 4rem);
  line-height: 1.05;
  letter-spacing: -.015em;
  margin: 0 0 clamp(1rem, 2.5vw, 1.5rem);
  max-width: 20ch;
}

.page-about .pa-hero-lead {
  margin: 0;
  max-width: 52ch;
  font-size: clamp(.95rem, 1.5vw, 1.075rem);
  line-height: 1.75;
  color: rgba(247, 248, 250, .82);
}

.page-about .pa-hero-stats {
  list-style: none;
  margin: clamp(1.5rem, 4vw, 2.5rem) 0 0;
  padding: clamp(1.25rem, 3vw, 1.75rem) 0 0;
  border-top: 1px solid rgba(247, 248, 250, .22);
  display: flex;
  flex-wrap: wrap;
  gap: clamp(1.25rem, 3vw, 2.75rem);
}

.page-about .stat-num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.6rem, 3.2vw, 2.6rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--signal);
}

.page-about .stat-label {
  display: block;
  margin-top: .45rem;
  font-size: .74rem;
  letter-spacing: .08em;
  color: rgba(247, 248, 250, .7);
}

.page-about .pa-hero-side {
  display: none;
  position: absolute;
  right: calc(var(--pa-pad) - .25rem);
  top: 50%;
  transform: translateY(-50%);
  z-index: 2;
}

.page-about .pa-vnote {
  display: block;
  writing-mode: vertical-rl;
  text-orientation: mixed;
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .32em;
  color: rgba(247, 248, 250, .55);
}

.page-about .pa-vnote--dark {
  color: rgba(247, 248, 250, .62);
}

/* ---------- 章节通用 ---------- */

.page-about .pa-eyebrow {
  margin: 0 0 .8rem;
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .24em;
  text-transform: uppercase;
}

.page-about .pa-sec--dark .pa-eyebrow {
  color: var(--signal);
}

.page-about .pa-sec--light .pa-eyebrow {
  color: var(--blue-light);
}

.page-about .pa-h2 {
  margin: 0 0 clamp(1rem, 2.5vw, 1.5rem);
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.45rem, 3.4vw, 2.4rem);
  line-height: 1.2;
  letter-spacing: -.01em;
  max-width: 24ch;
}

.page-about .lead {
  margin: 0 0 1rem;
  max-width: var(--read);
  font-size: clamp(.95rem, 1.4vw, 1.05rem);
  line-height: 1.8;
}

.page-about .pa-sec--dark .lead,
.page-about .pa-sec--dark .pa-body {
  color: rgba(247, 248, 250, .82);
}

.page-about .pa-body {
  margin: 0;
  max-width: var(--read);
  font-size: .95rem;
  line-height: 1.8;
}

.page-about .pa-note {
  margin: 1rem 0 0;
  max-width: var(--read);
  font-size: .82rem;
  line-height: 1.7;
  color: var(--mid);
}

.page-about .pa-sec--dark .pa-note {
  color: rgba(247, 248, 250, .62);
}

.page-about .pa-note a {
  color: inherit;
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .pa-note a:hover,
.page-about .pa-note a:focus-visible {
  color: var(--amber);
}

.page-about .pa-sec--light .pa-note a:hover,
.page-about .pa-sec--light .pa-note a:focus-visible {
  color: var(--blue-light);
}

/* ---------- 非对称双栏 ---------- */

.page-about .pa-two {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.25rem, 3vw, 2rem);
}

.page-about .pa-col-side {
  display: none;
}

/* ---------- 品牌定位数字带 ---------- */

.page-about .pa-facts {
  list-style: none;
  margin: clamp(1.75rem, 4vw, 2.75rem) 0 0;
  padding: 0;
  border-top: 1px solid rgba(247, 248, 250, .22);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.page-about .pa-facts li {
  padding: 1.1rem 1rem 1.1rem 0;
  border-bottom: 1px solid rgba(247, 248, 250, .16);
}

.page-about .pa-fact-num {
  display: block;
  font-size: clamp(1.35rem, 3vw, 2rem);
  font-weight: 700;
  line-height: 1.1;
  color: var(--text-inv);
}

.page-about .pa-fact-label {
  display: block;
  margin-top: .35rem;
  font-size: .76rem;
  letter-spacing: .06em;
  color: rgba(247, 248, 250, .68);
}

/* ---------- 授权模型 ---------- */

.page-about .pa-svg-wrap {
  margin: clamp(1.5rem, 3.5vw, 2.5rem) 0 0;
  padding: clamp(.75rem, 2vw, 1.5rem);
  background: var(--paper);
  border: 1px solid var(--line);
}

.page-about .pa-svg-wrap svg {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .pa-levels {
  margin-top: clamp(1.25rem, 2.5vw, 1.75rem);
  border-top: 1px solid var(--line);
}

.page-about .pa-level {
  border-bottom: 1px solid var(--line);
}

.page-about .pa-level summary {
  position: relative;
  cursor: pointer;
  list-style: none;
  padding: .95rem 2.25rem .95rem 0;
  font-size: .95rem;
  font-weight: 700;
  color: var(--text);
}

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

.page-about .pa-level summary::after {
  content: "";
  position: absolute;
  right: .5rem;
  top: 50%;
  width: .45rem;
  height: .45rem;
  border-right: 1.5px solid var(--blue-light);
  border-bottom: 1.5px solid var(--blue-light);
  transform: translateY(-70%) rotate(45deg);
  transition: transform .16s var(--ease), border-color .16s var(--ease);
}

.page-about .pa-level[open] summary::after {
  transform: translateY(-30%) rotate(-135deg);
  border-color: var(--signal);
}

.page-about .pa-level summary:hover,
.page-about .pa-level summary:focus-visible {
  color: var(--blue-light);
}

.page-about .pa-level p {
  margin: 0 0 1.1rem;
  max-width: var(--read);
  font-size: .9rem;
  line-height: 1.8;
  color: var(--text);
}

/* ---------- 图片 ---------- */

.page-about .pa-figure {
  margin: clamp(1.75rem, 4vw, 2.75rem) 0 0;
}

.page-about .pa-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid rgba(198, 206, 214, .5);
}

.page-about .pa-sec--dark .pa-figure img {
  border-color: rgba(247, 248, 250, .2);
}

.page-about .media-caption {
  margin-top: .75rem;
  max-width: var(--read);
  font-size: .78rem;
  line-height: 1.7;
  color: var(--mid);
}

.page-about .pa-sec--dark .media-caption {
  color: rgba(247, 248, 250, .62);
}

/* ---------- 批次号字段 ---------- */

.page-about .pa-code {
  list-style: none;
  margin: clamp(1.5rem, 3.5vw, 2.25rem) 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: .5rem;
}

.page-about .pa-code li {
  flex: 1 1 7rem;
  min-width: 0;
  padding: .9rem .85rem 1rem;
  border: 1px solid rgba(247, 248, 250, .26);
  background: rgba(247, 248, 250, .05);
}

.page-about .pa-code-seg {
  display: block;
  font-size: clamp(1.05rem, 2.2vw, 1.5rem);
  font-weight: 700;
  letter-spacing: .08em;
  color: var(--amber);
  line-height: 1.2;
  word-break: break-all;
}

.page-about .pa-code-name {
  display: block;
  margin-top: .4rem;
  font-size: .72rem;
  letter-spacing: .08em;
  color: rgba(247, 248, 250, .68);
}

/* ---------- 表格 ---------- */

.page-about .pa-table-wrap {
  margin-top: clamp(1.5rem, 3.5vw, 2.25rem);
  background: var(--paper);
  color: var(--text);
  padding: .5rem clamp(.75rem, 2vw, 1.25rem) .25rem;
  -webkit-overflow-scrolling: touch;
}

.page-about .pa-table-wrap--light {
  background: var(--paper);
}

.page-about .data-table {
  width: 100%;
  min-width: 34rem;
  border-collapse: collapse;
  font-size: .85rem;
}

.page-about .data-table caption {
  caption-side: top;
  text-align: left;
  padding: .85rem 0 .75rem;
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .16em;
  color: var(--mid);
}

.page-about .data-table th,
.page-about .data-table td {
  text-align: left;
  padding: .7rem .8rem;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
  line-height: 1.6;
}

.page-about .data-table th {
  font-size: .76rem;
  letter-spacing: .06em;
  font-weight: 700;
  color: var(--blue-light);
  white-space: nowrap;
}

.page-about .data-table td.mono,
.page-about .data-table .mono {
  font-family: var(--font-mono);
  font-weight: 700;
  letter-spacing: .04em;
}

.page-about .data-table tbody tr:hover {
  background: rgba(30, 111, 168, .07);
}

/* ---------- 复核节奏 ---------- */

.page-about .pa-cycles {
  list-style: none;
  margin: clamp(1.5rem, 3.5vw, 2.25rem) 0 0;
  padding: 0;
}

.page-about .pa-cycles li {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem 1rem;
  align-items: baseline;
  padding: .85rem 0;
  border-top: 1px solid rgba(247, 248, 250, .2);
  font-size: .88rem;
  line-height: 1.7;
  color: rgba(247, 248, 250, .86);
}

.page-about .pa-cycles .mono {
  flex: 0 0 auto;
  min-width: 3.5rem;
  font-size: .78rem;
  letter-spacing: .12em;
  color: var(--amber);
}

.page-about .pa-cycles li span:last-child {
  flex: 1 1 12rem;
  min-width: 0;
}

/* ---------- 时间带 ---------- */

.page-about .pa-track {
  margin-top: clamp(1.5rem, 3.5vw, 2.25rem);
  padding-bottom: 1rem;
  border-top: 1px solid rgba(247, 248, 250, .26);
  display: flex;
  overflow-x: auto;
  overflow-y: hidden;
  scroll-snap-type: x proximity;
  -webkit-overflow-scrolling: touch;
  cursor: grab;
}

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

.page-about .pa-tl-item {
  flex: 0 0 min(76vw, 19rem);
  scroll-snap-align: start;
  margin-right: 1.5rem;
  padding: 1.75rem 1.5rem 1.75rem 0;
  border-right: 1px solid rgba(247, 248, 250, .2);
}

.page-about .pa-tl-year {
  display: block;
  font-size: clamp(1.35rem, 3vw, 1.9rem);
  font-weight: 700;
  letter-spacing: .02em;
  color: var(--amber);
  line-height: 1.1;
}

.page-about .pa-tl-item--current .pa-tl-year {
  color: var(--signal);
}

.page-about .pa-tl-title {
  margin: .9rem 0 .6rem;
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.45;
  color: var(--text-inv);
}

.page-about .pa-tl-item p {
  margin: 0;
  font-size: .85rem;
  line-height: 1.75;
  color: rgba(247, 248, 250, .75);
}

.page-about .pa-track-hint {
  margin: .75rem 0 0;
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .16em;
  color: rgba(247, 248, 250, .55);
}

/* ---------- 本地化支持 ---------- */

.page-about .pa-local-grid {
  margin: clamp(1.5rem, 3.5vw, 2.25rem) 0 0;
  gap: clamp(1.5rem, 4vw, 3rem);
  grid-template-columns: minmax(0, 1fr);
}

.page-about .pa-local-grid h3 {
  margin: 0 0 .85rem;
  font-size: .95rem;
  font-weight: 700;
  letter-spacing: .06em;
  color: var(--text-inv);
}

.page-about .pa-local-grid ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .pa-local-grid li {
  position: relative;
  padding: .75rem 0 .75rem 1.2rem;
  border-top: 1px solid rgba(247, 248, 250, .18);
  font-size: .87rem;
  line-height: 1.75;
  color: rgba(247, 248, 250, .84);
}

.page-about .pa-local-grid li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 1.4rem;
  width: .5rem;
  height: 1px;
  background: var(--signal);
}

.page-about .pa-btn-row {
  margin-top: clamp(1.5rem, 3.5vw, 2.25rem);
}

/* ---------- 按钮 ---------- */

.page-about .btn-primary {
  background: var(--signal);
  border-color: var(--signal);
  color: #101418;
  font-weight: 700;
}

.page-about .btn-primary:hover,
.page-about .btn-primary:focus-visible {
  background: var(--amber);
  border-color: var(--amber);
}

.page-about .btn-ghost {
  background: transparent;
  border-color: rgba(247, 248, 250, .42);
  color: var(--text-inv);
}

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

/* ---------- 结尾联系条 ---------- */

.page-about .pa-strip {
  background: var(--deep);
  color: var(--text-inv);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1.25rem;
  border-top: 1px solid rgba(247, 248, 250, .16);
}

.page-about .pa-strip p {
  margin: 0;
  max-width: 48ch;
  font-size: .9rem;
  line-height: 1.75;
  color: rgba(247, 248, 250, .82);
}

.page-about .pa-strip .btn-row {
  margin-top: 0;
}

/* ---------- 右侧索引 ---------- */

.page-about .pa-toc {
  display: none;
}

.page-about .pa-toc-title {
  margin: 0 0 1rem;
  font-family: var(--font-mono);
  font-size: .68rem;
  letter-spacing: .26em;
  text-transform: uppercase;
  color: var(--mid);
}

.page-about .toc-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: .1rem;
}

.page-about .toc-link {
  display: block;
  padding: .45rem 0 .45rem .7rem;
  font-size: .78rem;
  line-height: 1.5;
  color: var(--mid);
  text-decoration: none;
  border-left: 2px solid transparent;
  transition: color .16s var(--ease), border-color .16s var(--ease);
}

.page-about .toc-link:hover,
.page-about .toc-link:focus-visible {
  color: var(--blue);
  border-left-color: var(--line);
}

.page-about .toc-link.is-active {
  color: var(--blue);
  border-left-color: var(--signal);
}

/* ---------- 媒体查询 ---------- */

@media (min-width: 640px) {
  .page-about .pa-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .pa-facts li {
    padding-right: 1.25rem;
    border-bottom: 0;
  }

  .page-about .pa-tl-item {
    flex: 0 0 18rem;
  }
}

@media (min-width: 860px) {
  .page-about .pa-two {
    grid-template-columns: minmax(0, 1fr) 3.5rem;
    gap: clamp(1.5rem, 3vw, 2.5rem);
  }

  .page-about .pa-col-side {
    display: block;
    padding-top: .4rem;
  }

  .page-about .pa-col-side .pa-vnote {
    margin-left: auto;
  }

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

@media (min-width: 900px) {
  .page-about .pa-hero-side {
    display: block;
  }
}

@media (min-width: 1080px) {
  .page-about .pa-frame {
    grid-template-columns: minmax(0, 1fr) 14rem;
  }

  .page-about .pa-toc {
    display: block;
    position: sticky;
    top: 6rem;
    align-self: start;
    padding: 4rem 1.25rem 3rem 1.5rem;
    border-left: 1px solid var(--line);
  }

  .page-about .pa-tl-item {
    flex: 0 0 20rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .pa-level summary::after,
  .page-about .toc-link {
    transition: none;
  }
}
</style>