.page-about {
  --about-toc-width: 264px;
  scroll-behavior: smooth;
  background: var(--color-bg);
  color: var(--color-ink);
  font-family: var(--font-body);
}

.page-about .about-layout {
  display: grid;
  grid-template-columns: 1fr;
  width: 100%;
  min-width: 0;
}

.page-about .about-canvas {
  min-width: 0;
  width: 100%;
}

/* ---------- 左侧章节索引 ---------- */
.page-about .about-toc {
  position: sticky;
  top: var(--header-h);
  z-index: 20;
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-grid);
}
.page-about .about-toc__inner {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 10px var(--shell-pad);
  min-width: max-content;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
}
.page-about .about-toc__inner::-webkit-scrollbar {
  display: none;
}
.page-about .about-toc__term {
  flex: 0 0 auto;
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-teal);
  white-space: nowrap;
}
.page-about .about-toc__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: 2px;
}
.page-about .about-toc__item {
  flex: 0 0 auto;
  margin: 0;
}
.page-about .about-toc__link {
  display: flex;
  align-items: baseline;
  gap: 6px;
  padding: 8px 10px;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-ink);
  text-decoration: none;
  border-radius: 2px;
  white-space: nowrap;
  transition: background-color 0.2s ease, color 0.2s ease;
}
.page-about .about-toc__link:hover {
  background: var(--color-paper);
  color: var(--color-blue);
}
.page-about .about-toc__link:focus-visible {
  outline: 2px solid var(--color-red);
  outline-offset: 2px;
}
.page-about .about-toc__no {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--color-red);
}
.page-about .about-toc__note {
  display: flex;
  gap: 8px;
  flex: 0 0 auto;
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--color-ink);
  white-space: nowrap;
}
.page-about .about-toc__note a {
  color: var(--color-ink);
  text-decoration: none;
  border-bottom: 1px solid var(--color-grid);
  transition: color 0.2s ease, border-color 0.2s ease;
}
.page-about .about-toc__note a:hover {
  color: var(--color-red);
  border-color: var(--color-red);
}

/* ---------- 通用章节 ---------- */
.page-about .about-section {
  position: relative;
  scroll-margin-top: calc(var(--header-h) + 16px);
}
.page-about .about-section__header {
  max-width: 860px;
  margin: 0 auto 36px;
}
.page-about .about-section__header h2 {
  margin: 10px 0 12px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.9rem, 4.5vw, 3.2rem);
  line-height: 1.05;
  letter-spacing: 0.02em;
  color: var(--color-blue);
}
.page-about .about-section__lede {
  margin: 0;
  max-width: 36em;
  font-size: 1rem;
  line-height: 1.7;
  color: var(--color-ink);
}

/* ---------- 01 门道宣言 ---------- */
.page-about .about-manifesto {
  background: var(--color-blue);
  color: var(--color-paper);
  overflow: hidden;
  padding: clamp(56px, 9vw, 120px) var(--shell-pad);
}
.page-about .about-manifesto::before {
  content: "";
  position: absolute;
  right: -12%;
  top: -10%;
  width: 56%;
  height: 130%;
  background: repeating-linear-gradient(-55deg, transparent 0, transparent 18px, rgba(57,255,20,0.05) 18px, rgba(57,255,20,0.05) 20px);
  transform: skewX(-8deg);
  pointer-events: none;
}
.page-about .about-manifesto::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, var(--color-green) 0, var(--color-green) 24%, transparent 24%);
  opacity: 0.6;
  pointer-events: none;
}
.page-about .about-manifesto__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  max-width: 1120px;
  margin: 0 auto;
  align-items: center;
  position: relative;
  z-index: 1;
}
.page-about .about-manifesto__content {
  max-width: 640px;
}
.page-about .about-manifesto .eyebrow {
  color: var(--color-green);
}
.page-about .about-breadcrumbs {
  margin-bottom: 24px;
}
.page-about .about-breadcrumbs .breadcrumbs__list {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  list-style: none;
  margin: 0;
  padding: 0;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.page-about .about-breadcrumbs .breadcrumbs__item {
  display: flex;
  align-items: center;
  gap: 6px;
}
.page-about .about-breadcrumbs .breadcrumbs__item + .breadcrumbs__item::before {
  content: "·";
  color: rgba(255,253,249,0.5);
}
.page-about .about-breadcrumbs .breadcrumbs__link {
  color: rgba(255,253,249,0.7);
  text-decoration: none;
  transition: color 0.2s ease;
}
.page-about .about-breadcrumbs .breadcrumbs__link:hover {
  color: var(--color-green);
}
.page-about .about-breadcrumbs .breadcrumbs__current {
  color: var(--color-green);
}
.page-about .about-manifesto h1 {
  margin: 12px 0 20px;
  max-width: 12em;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(2.4rem, 6vw, 4.6rem);
  line-height: 0.98;
  letter-spacing: 0.01em;
  color: var(--color-paper);
}
.page-about .about-manifesto__lede {
  margin: 0 0 28px;
  max-width: 30em;
  padding-left: 16px;
  border-left: 3px solid var(--color-green);
  font-size: clamp(1.05rem, 1.8vw, 1.3rem);
  line-height: 1.6;
  color: rgba(255,253,249,0.92);
}
.page-about .about-manifesto__body p {
  margin: 0 0 14px;
  max-width: 52em;
  font-size: 0.95rem;
  line-height: 1.8;
  color: rgba(255,253,249,0.78);
}
.page-about .about-manifesto__axis {
  display: block;
  margin-top: 22px;
  max-width: 220px;
  height: auto;
}
.page-about .about-manifesto__facts {
  list-style: none;
  margin: 26px 0 0;
  padding: 20px 0 0;
  border-top: 1px solid rgba(185,199,217,0.24);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px 20px;
}
.page-about .about-manifesto__facts li {
  display: flex;
  flex-direction: column;
  gap: 2px;
  font-size: 0.84rem;
  line-height: 1.4;
  color: rgba(255,253,249,0.85);
}
.page-about .about-manifesto__facts span {
  font-family: var(--font-mono);
  font-size: 1.1rem;
  color: var(--color-green);
}
.page-about .about-manifesto__media {
  position: relative;
  max-width: 440px;
  margin-left: auto;
  margin-right: auto;
}
.page-about .about-manifesto__media::before {
  content: "";
  position: absolute;
  inset: 0;
  border: 1px solid rgba(185,199,217,0.4);
  transform: translate(14px, 14px);
  pointer-events: none;
}
.page-about .about-manifesto__media img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  filter: saturate(0.9) contrast(1.05);
}
.page-about .about-manifesto__media figcaption,
.page-about .about-compliance__media figcaption {
  margin-top: 10px;
  padding-top: 10px;
  border-top: 1px solid rgba(185,199,217,0.2);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: rgba(255,253,249,0.6);
}

/* ---------- 02 成长档案 ---------- */
.page-about .about-timeline {
  background: var(--color-bg);
  padding: clamp(56px, 8vw, 100px) var(--shell-pad);
}
.page-about .about-timeline::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: linear-gradient(to right, rgba(185,199,217,0.2) 1px, transparent 1px);
  background-size: 64px 100%;
  pointer-events: none;
}
.page-about .about-timeline__header {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
  align-items: end;
}
.page-about .about-timeline__rule {
  display: none;
}
.page-about .about-timeline__list {
  position: relative;
  z-index: 1;
  list-style: none;
  margin: 0;
  padding: 0;
  max-width: 820px;
}
.page-about .about-timeline__list::before {
  content: "";
  position: absolute;
  left: 13px;
  top: 6px;
  bottom: 6px;
  width: 2px;
  background: linear-gradient(to bottom, var(--color-grid), var(--color-teal));
}
.page-about .about-timeline__item {
  position: relative;
  padding-left: 44px;
  padding-bottom: 32px;
}
.page-about .about-timeline__item:last-child {
  padding-bottom: 0;
}
.page-about .about-timeline__marker {
  position: absolute;
  left: 7px;
  top: 8px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--color-green);
  border: 3px solid var(--color-bg);
  box-shadow: 0 0 0 2px var(--color-blue);
}
.page-about .about-timeline__year {
  margin-bottom: 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(2rem, 4vw, 2.8rem);
  line-height: 1;
  letter-spacing: 0.03em;
  color: var(--color-blue);
}
.page-about .about-timeline__card {
  max-width: 560px;
  font-size: 0.95rem;
  line-height: 1.7;
  color: var(--color-ink);
}
.page-about .about-timeline__card summary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
  list-style: none;
  font-weight: 600;
  color: var(--color-blue);
  outline: none;
}
.page-about .about-timeline__card summary::-webkit-details-marker {
  display: none;
}
.page-about .about-timeline__card summary::before {
  content: "＋";
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--color-red);
  transition: transform 0.2s ease;
}
.page-about .about-timeline__card[open] summary::before {
  transform: rotate(45deg);
}
.page-about .about-timeline__card summary:focus-visible {
  outline: 2px solid var(--color-red);
  outline-offset: 4px;
}
.page-about .about-timeline__card p {
  margin: 10px 0 0 22px;
  padding: 14px 16px;
  background: var(--color-paper);
  border-left: 2px solid var(--color-orange);
  font-size: 0.9rem;
}

/* ---------- 03 数据航路 ---------- */
.page-about .about-route {
  background: var(--color-paper);
  padding: clamp(56px, 8vw, 100px) var(--shell-pad);
  overflow: hidden;
}
.page-about .about-route::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, rgba(185,199,217,0.14) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(185,199,217,0.1) 1px, transparent 1px);
  background-size: 64px 64px;
  pointer-events: none;
}
.page-about .about-route__grid {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
  max-width: 1000px;
  margin: 0 auto;
}
.page-about .about-route__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}
.page-about .about-route__stat {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 18px 14px;
  background: var(--color-bg);
  border-top: 3px solid var(--color-blue);
}
.page-about .about-route__stat .stat__value {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(2.2rem, 4vw, 3.4rem);
  line-height: 1;
  color: var(--color-blue);
}
.page-about .about-route__stat .stat__unit {
  margin-left: 2px;
  font-family: var(--font-display);
  font-size: 0.5em;
  color: var(--color-red);
}
.page-about .about-route__stat .stat__label {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  line-height: 1.4;
  color: var(--color-ink);
}
.page-about .about-route__table {
  position: relative;
  z-index: 1;
  max-width: 1000px;
  margin: 0 auto;
}
.page-about .about-route__table table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.875rem;
  background: var(--color-paper);
}
.page-about .about-route__table th {
  padding: 12px 14px;
  border-bottom: 2px solid var(--color-blue);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  text-align: left;
  color: var(--color-blue);
}
.page-about .about-route__table td {
  padding: 12px 14px;
  border-bottom: 1px solid var(--color-grid);
  line-height: 1.5;
  color: var(--color-ink);
}
.page-about .about-route__table tbody tr:hover {
  background: rgba(185,199,217,0.14);
}
.page-about .about-route .note {
  position: relative;
  z-index: 1;
  max-width: 1000px;
  margin: 24px auto 0;
  padding: 14px 16px;
  border-left: 3px solid var(--color-teal);
  background: rgba(62,122,118,0.08);
  font-size: 0.9rem;
}
.page-about .about-route .note strong {
  color: var(--color-blue);
}
.page-about .about-route__leagues {
  position: relative;
  z-index: 1;
  max-width: 1000px;
  margin: 20px auto 0;
  border: 1px solid var(--color-grid);
  background: var(--color-bg);
}
.page-about .about-route__leagues summary {
  cursor: pointer;
  list-style: none;
  padding: 12px 16px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-blue);
}
.page-about .about-route__leagues summary::-webkit-details-marker {
  display: none;
}
.page-about .about-route__leagues summary:focus-visible {
  outline: 2px solid var(--color-red);
  outline-offset: 2px;
}
.page-about .about-route__league-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 4px 16px 16px;
}
.page-about .about-route__league-list li {
  padding: 4px 10px;
  background: var(--color-paper);
  border: 1px solid var(--color-grid);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--color-ink);
}

/* ---------- 04 频道地图 ---------- */
.page-about .about-channels {
  background: var(--color-bg);
  padding: clamp(56px, 8vw, 100px) var(--shell-pad);
}
.page-about .about-channels::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(90deg, var(--color-orange) 0 12%, var(--color-blue) 12% 100%);
  pointer-events: none;
}
.page-about .about-channels__content {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  max-width: 1000px;
  margin: 0 auto;
  align-items: start;
}
.page-about .about-channels__list {
  list-style: none;
  margin: 0;
  padding: 0;
}
.page-about .about-channels__item {
  display: grid;
  grid-template-columns: 44px 1fr;
  gap: 2px 16px;
  padding: 20px 0;
  border-bottom: 1px solid var(--color-grid);
}
.page-about .about-channels__item:first-child {
  border-top: 1px solid var(--color-grid);
}
.page-about .about-channels__no {
  grid-row: 1 / 3;
  font-family: var(--font-mono);
  font-weight: 500;
  font-size: 0.85rem;
  line-height: 1.4;
  color: var(--color-red);
}
.page-about .about-channels__item h3 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.5rem;
  letter-spacing: 0.02em;
  line-height: 1.2;
  color: var(--color-blue);
}
.page-about .about-channels__item p {
  margin: 4px 0 0;
  max-width: 46em;
  font-size: 0.9rem;
  line-height: 1.65;
  color: var(--color-ink);
}
.page-about .about-channels__media {
  margin: 0;
}
.page-about .about-channels__media img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}
.page-about .about-channels__media figcaption {
  margin-top: 10px;
  padding-top: 10px;
  border-top: 1px solid var(--color-grid);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--color-ink);
}

/* ---------- 05 合规与服务 ---------- */
.page-about .about-compliance {
  background: var(--color-blue);
  color: var(--color-paper);
  padding: 0 var(--shell-pad);
}
.page-about .about-compliance::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 28px;
  background: linear-gradient(105deg, var(--color-bg) 0%, var(--color-bg) 46%, var(--color-blue) 46%, var(--color-blue) 100%);
  pointer-events: none;
}
.page-about .about-compliance__inner {
  position: relative;
  max-width: 1000px;
  margin: 0 auto;
  padding: clamp(56px, 8vw, 100px) 0;
}
.page-about .about-compliance .eyebrow {
  color: var(--color-green);
}
.page-about .about-compliance h2 {
  margin: 10px 0 16px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(2rem, 4.5vw, 3.4rem);
  letter-spacing: 0.02em;
  color: var(--color-paper);
}
.page-about .about-compliance .about-section__lede {
  margin: 0;
  max-width: 34em;
  font-size: 1rem;
  line-height: 1.7;
  color: rgba(255,253,249,0.76);
}
.page-about .about-compliance__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  margin-top: 36px;
}
.page-about .about-compliance__info {
  display: grid;
  gap: 0;
  margin: 0;
  padding: 0;
  background: var(--color-blue-soft);
}
.page-about .about-compliance__row {
  display: grid;
  grid-template-columns: 96px 1fr;
  gap: 16px;
  padding: 16px 18px;
  border-bottom: 1px solid rgba(185,199,217,0.18);
}
.page-about .about-compliance__row:last-child {
  border-bottom: 0;
}
.page-about .about-compliance__row dt {
  padding-top: 2px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-green);
}
.page-about .about-compliance__row dd {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.6;
  color: var(--color-paper);
  overflow-wrap: anywhere;
}
.page-about .about-compliance__media {
  margin: 0;
}
.page-about .about-compliance__media img {
  display: block;
  width: 100%;
  height: auto;
}
.page-about .about-compliance__faq {
  list-style: none;
  margin: 36px 0 0;
  padding: 24px 0 0;
  border-top: 1px solid rgba(185,199,217,0.2);
  display: grid;
  gap: 12px;
}
.page-about .about-compliance__faq li {
  padding: 12px 16px;
  border-left: 2px solid var(--color-orange);
  background: rgba(255,255,255,0.03);
  font-size: 0.9rem;
  line-height: 1.7;
  color: rgba(255,253,249,0.86);
}
.page-about .about-compliance__faq strong {
  color: var(--color-paper);
  font-weight: 600;
}
.page-about .about-compliance__statement {
  margin-top: 28px;
  padding: 16px 18px;
  border: 1px dashed rgba(185,199,217,0.28);
  font-size: 0.85rem;
  line-height: 1.7;
  color: rgba(255,253,249,0.65);
}
.page-about .about-compliance__statement p {
  margin: 0 0 8px;
}
.page-about .about-compliance__statement p:last-child {
  margin-bottom: 0;
}
.page-about .about-compliance__statement a {
  color: var(--color-green);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- 桌面端进阶布局 ---------- */
@media (min-width: 1024px) {
  .page-about .about-layout {
    grid-template-columns: var(--about-toc-width) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-toc {
    min-height: 100vh;
    border-bottom: 0;
    border-right: 1px solid var(--color-grid);
  }
  .page-about .about-toc__inner {
    flex-direction: column;
    align-items: flex-start;
    gap: 28px;
    min-width: 0;
    padding: 56px 28px 48px clamp(20px, 3vw, 40px);
    overflow: visible;
  }
  .page-about .about-toc__list {
    flex-direction: column;
    gap: 2px;
    width: 100%;
  }
  .page-about .about-toc__link {
    width: 100%;
    padding: 10px 8px;
    border-left: 2px solid transparent;
    border-radius: 0;
  }
  .page-about .about-toc__link:hover {
    border-left-color: var(--color-orange);
    background: transparent;
  }
  .page-about .about-toc__note {
    flex-direction: column;
    gap: 6px;
    margin-top: auto;
  }

  .page-about .about-manifesto__grid {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
    gap: clamp(32px, 6vw, 80px);
  }
  .page-about .about-manifesto__media {
    max-width: 460px;
  }

  .page-about .about-timeline__header {
    grid-template-columns: 1fr auto;
  }
  .page-about .about-timeline__rule {
    display: block;
  }

  .page-about .about-route__grid {
    grid-template-columns: 0.85fr 1.15fr;
    gap: 40px;
  }

  .page-about .about-channels__content {
    grid-template-columns: 1.1fr 0.9fr;
    gap: 48px;
  }
  .page-about .about-channels__media {
    position: sticky;
    top: calc(var(--header-h) + 32px);
  }

  .page-about .about-compliance__grid {
    grid-template-columns: 1.15fr 0.85fr;
    gap: 48px;
    align-items: center;
  }
}