.page-about {
  --about-line: 1px solid var(--c-grid);
  --about-grid-size: 28px;
  --about-shadow: 0 8px 24px rgba(0, 0, 0, 0.25);
}

/* ===================== 档案页头 ===================== */
.page-about .about-hero {
  position: relative;
  background:
    linear-gradient(rgba(42, 59, 102, 0.35) 1px, transparent 1px),
    linear-gradient(90deg, rgba(42, 59, 102, 0.35) 1px, transparent 1px),
    linear-gradient(180deg, rgba(10, 17, 40, 0.2), rgba(16, 27, 62, 0.98)),
    var(--c-panel);
  background-size: var(--about-grid-size) var(--about-grid-size),
    var(--about-grid-size) var(--about-grid-size), 100% 100%, 100%;
  border-bottom: var(--about-line);
  padding: 32px 0 40px;
}

.page-about .about-hero::after {
  content: '';
  position: absolute;
  top: 0;
  right: 0;
  width: 190px;
  height: 4px;
  background: linear-gradient(90deg, transparent, var(--c-accent));
  transform: rotate(-12deg);
  transform-origin: right top;
  opacity: 0.65;
  pointer-events: none;
}

.page-about .about-hero__grid {
  display: grid;
  gap: 30px;
  margin-top: 28px;
}

.page-about .about-hero__main {
  max-width: 820px;
}

.page-about .about-hero__kicker {
  display: block;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--c-accent-2);
  text-transform: uppercase;
  margin-bottom: 16px;
}

.page-about .about-hero__title {
  font-family: var(--font-heading);
  font-size: clamp(28px, 5.5vw, 52px);
  line-height: 1.08;
  text-transform: uppercase;
  letter-spacing: 0.02em;
  margin: 0 0 14px;
  color: var(--c-text);
  position: relative;
  padding-left: 16px;
  border-left: 4px solid var(--c-accent);
}

.page-about .about-hero__lead {
  font-size: var(--body-size);
  line-height: 1.7;
  color: var(--c-text-dim);
  margin: 0 0 20px;
}

.page-about .about-hero__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .about-hero__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 18px;
  margin-top: 18px;
  padding-top: 14px;
  border-top: var(--about-line);
  font-size: 12px;
  color: var(--c-text-dim);
  letter-spacing: 0.08em;
}

/* 目录卡片 */
.page-about .about-toc {
  background: var(--c-overlay);
  border: var(--about-line);
  position: relative;
  padding: 18px 18px 22px;
  margin-top: 8px;
  box-shadow: var(--about-shadow);
}

.page-about .about-toc::before {
  content: '▟';
  position: absolute;
  right: 12px;
  top: 10px;
  font-size: 20px;
  color: var(--c-accent);
  line-height: 1;
}

.page-about .about-toc__label {
  display: block;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--c-accent-2);
  border-bottom: var(--about-line);
  padding-bottom: 10px;
  margin-bottom: 12px;
}

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

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

.page-about .about-toc__list a {
  display: flex;
  gap: 12px;
  align-items: baseline;
  color: var(--c-text);
  text-decoration: none;
  font-size: 14px;
  padding: 6px 8px;
  border-radius: 2px;
  transition: background var(--ease), color var(--ease);
}

.page-about .about-toc__list a:hover,
.page-about .about-toc__list a:focus-visible {
  background: var(--c-index);
  color: var(--c-accent);
}

.page-about .about-toc__list a .mono {
  color: var(--c-accent);
  font-size: 12px;
}

/* ===================== 01 品牌定位 ===================== */
.page-about .about-position__grid {
  display: grid;
  gap: 28px;
}

.page-about .about-position__panel {
  padding: 24px;
}

.page-about .about-position__quote {
  display: block;
  font-family: var(--font-heading);
  font-size: 24px;
  line-height: 1.3;
  padding: 16px 20px;
  background: linear-gradient(135deg, rgba(0, 229, 160, 0.1), transparent 60%);
  border-left: 4px solid var(--c-accent);
  margin-bottom: 18px;
}

.page-about .about-position__copy {
  font-size: 14px;
  line-height: 1.75;
  color: var(--c-text-dim);
  margin: 0 0 14px;
}

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

.page-about .about-position__aside {
  display: grid;
  gap: 12px;
  align-content: start;
}

.page-about .about-position__fact {
  background: var(--c-panel);
  border: var(--about-line);
  border-left: 3px solid var(--c-accent);
  padding: 18px 16px;
  text-align: center;
  position: relative;
}

.page-about .about-position__fact:nth-child(2) {
  border-left-color: var(--c-accent-2);
}

.page-about .about-position__fact:nth-child(3) {
  border-left-color: #3D7EFF;
}

.page-about .about-position__fact-num {
  display: block;
  font-family: var(--font-heading);
  font-size: 32px;
  line-height: 1;
  color: var(--c-text);
  margin-bottom: 6px;
}

.page-about .about-position__fact-label {
  font-size: 12px;
  color: var(--c-text-dim);
  letter-spacing: 0.06em;
}

.page-about .about-position__note {
  margin: 4px 0 0;
  font-size: 11px;
  text-align: right;
  color: var(--c-accent);
  letter-spacing: 0.1em;
}

/* ===================== 02 发展历程 ===================== */
.page-about .about-history {
  background:
    linear-gradient(rgba(42, 59, 102, 0.3) 1px, transparent 1px),
    linear-gradient(90deg, rgba(42, 59, 102, 0.3) 1px, transparent 1px),
    var(--c-panel);
  background-size: 32px 32px, 32px 32px, 100%;
  border-top: var(--about-line);
  border-bottom: var(--about-line);
}

.page-about .about-history__layout {
  display: grid;
  gap: 30px;
}

.page-about .about-history__timeline {
  position: relative;
  padding: 4px 0 4px 20px;
  border-left: 2px solid var(--c-grid);
}

.page-about .about-tl-node {
  position: relative;
  margin: 0 0 12px;
  background: var(--c-bg);
  border: 1px solid rgba(42, 59, 102, 0.7);
  padding: 14px 16px;
}

.page-about .about-tl-node::before {
  content: '';
  position: absolute;
  left: -25px;
  top: 17px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--c-accent);
  border: 2px solid var(--c-bg);
}

.page-about .about-tl-node[open]::before {
  background: var(--c-accent-2);
}

.page-about .about-tl-node__head {
  list-style: none;
  position: relative;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
  cursor: pointer;
  padding-right: 24px;
  outline: none;
}

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

.page-about .about-tl-node__head::after {
  content: '+';
  position: absolute;
  right: 0;
  top: 0;
  font-family: var(--font-mono);
  font-size: 16px;
  line-height: 1;
  color: var(--c-accent-2);
  transition: transform var(--ease);
}

.page-about .about-tl-node[open] .about-tl-node__head::after {
  content: '−';
}

.page-about .about-tl-node__year {
  font-family: var(--font-mono);
  font-size: 20px;
  font-weight: 700;
  color: var(--c-accent);
}

.page-about .about-tl-node__title {
  font-family: var(--font-heading);
  font-size: 17px;
  letter-spacing: 0.03em;
  color: var(--c-text);
  text-transform: uppercase;
}

.page-about .about-tl-node__ver {
  margin-left: auto;
  font-size: 12px;
  color: var(--c-text-dim);
  background: var(--c-index);
  padding: 2px 6px;
  border-radius: 2px;
}

.page-about .about-tl-node__desc {
  font-size: 13px;
  line-height: 1.65;
  color: var(--c-text-dim);
  margin: 12px 0 4px;
  padding-top: 10px;
  border-top: 1px dashed var(--c-grid);
}

/* 里程碑图 */
.page-about .about-history__media {
  margin: 0;
  border: var(--about-line);
  background: var(--c-bg);
  position: relative;
}

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

.page-about .about-media__caption {
  font-size: 12px;
  color: var(--c-text-dim);
  padding: 10px 12px;
  border-top: var(--about-line);
  background: var(--c-panel);
}

/* ===================== 03 数据与团队 ===================== */
.page-about .about-team__grid {
  display: grid;
  gap: 30px;
}

.page-about .about-team__subtitle {
  font-family: var(--font-heading);
  font-size: 20px;
  line-height: 1.25;
  color: var(--c-accent);
  margin: 0 0 12px;
  padding-top: 20px;
  border-top: var(--about-line);
  letter-spacing: 0.03em;
}

.page-about .about-team__subtitle:first-child {
  padding-top: 0;
  border-top: none;
}

.page-about .about-team__copy {
  font-size: 14px;
  line-height: 1.75;
  color: var(--c-text-dim);
  margin: 0 0 14px;
}

.page-about .about-team__list {
  list-style: none;
  margin: 12px 0 0;
  padding: 0;
}

.page-about .about-team__list li {
  position: relative;
  padding: 12px 0 12px 26px;
  border-bottom: 1px dashed var(--c-grid);
  font-size: 14px;
  line-height: 1.6;
  color: var(--c-text-dim);
}

.page-about .about-team__list li::before {
  content: '▸';
  position: absolute;
  left: 4px;
  top: 11px;
  color: var(--c-accent);
  font-family: var(--font-mono);
}

.page-about .about-team__list li strong {
  color: var(--c-text);
  font-weight: 500;
  margin-right: 6px;
}

.page-about .about-team__aside {
  display: grid;
  gap: 12px;
  align-content: start;
}

.page-about .about-team__stat {
  background: var(--c-panel);
  border: var(--about-line);
  border-top: 3px solid var(--c-accent);
  padding: 18px 16px;
  text-align: center;
}

.page-about .about-team__stat:nth-child(2) {
  border-top-color: var(--c-accent-2);
}

.page-about .about-team__stat:nth-child(3) {
  border-top-color: #3D7EFF;
}

.page-about .about-team__stat-num {
  display: block;
  font-family: var(--font-heading);
  font-size: 30px;
  line-height: 1;
  color: var(--c-text);
  margin-bottom: 6px;
}

.page-about .about-team__stat-label {
  font-size: 12px;
  color: var(--c-text-dim);
  letter-spacing: 0.06em;
}

.page-about .about-team__media {
  margin: 4px 0 0;
  border: var(--about-line);
  background: var(--c-bg);
}

/* ===================== 04 安全与合规 ===================== */
.page-about .about-security {
  background:
    linear-gradient(rgba(42, 59, 102, 0.3) 1px, transparent 1px),
    linear-gradient(90deg, rgba(42, 59, 102, 0.3) 1px, transparent 1px),
    var(--c-panel);
  background-size: 32px 32px, 32px 32px, 100%;
  border-top: var(--about-line);
  border-bottom: var(--about-line);
}

.page-about .about-security__grid {
  display: grid;
  gap: 30px;
}

.page-about .about-security__certs {
  display: grid;
  gap: 16px;
  align-content: start;
}

.page-about .about-security__cert {
  background: var(--c-bg);
  border: var(--about-line);
  border-top: 3px solid var(--c-accent);
  padding: 18px 18px 20px;
  position: relative;
}

.page-about .about-security__cert:nth-child(2) {
  border-top-color: var(--c-accent-2);
}

.page-about .about-security__cert-tag {
  display: inline-block;
  margin-bottom: 12px;
}

.page-about .about-security__cert-title {
  font-family: var(--font-heading);
  font-size: 18px;
  line-height: 1.3;
  color: var(--c-text);
  margin: 0 0 8px;
  letter-spacing: 0.02em;
}

.page-about .about-security__cert-desc {
  font-size: 14px;
  line-height: 1.7;
  color: var(--c-text-dim);
  margin: 0;
}

.page-about .about-security__meta {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 8px;
  background: var(--c-index);
  border: 1px dashed var(--c-accent);
  padding: 14px 16px;
  margin-top: 4px;
}

.page-about .about-security__meta-label {
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--c-text-dim);
}

.page-about .about-security__meta-value {
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--c-accent);
  letter-spacing: 0.06em;
}

.page-about .about-security__media {
  margin: 0;
  border: var(--about-line);
  background: var(--c-bg);
  align-self: start;
}

/* ===================== 05 合作与荣誉 ===================== */
.page-about .about-honor__grid {
  display: grid;
  gap: 30px;
}

.page-about .about-honor__intro {
  font-size: 15px;
  line-height: 1.75;
  color: var(--c-text);
  margin: 0 0 20px;
  padding-left: 16px;
  border-left: 3px solid var(--c-accent-2);
}

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

.page-about .about-honor__list li {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 14px 0;
  border-bottom: 1px dashed var(--c-grid);
  font-size: 14px;
  line-height: 1.6;
  color: var(--c-text-dim);
}

.page-about .about-honor__list li .tag {
  flex-shrink: 0;
  margin-top: 2px;
}

.page-about .about-honor__awards {
  display: grid;
  gap: 14px;
  align-content: start;
}

.page-about .about-honor__award {
  background: var(--c-panel);
  border: var(--about-line);
  padding: 20px 20px 22px;
  position: relative;
  overflow: hidden;
}

.page-about .about-honor__award::after {
  content: '';
  position: absolute;
  right: 0;
  bottom: 0;
  border-left: 48px solid transparent;
  border-bottom: 48px solid rgba(0, 229, 160, 0.08);
}

.page-about .about-honor__award:nth-child(2)::after {
  border-bottom-color: rgba(255, 122, 26, 0.1);
}

.page-about .about-honor__award-year {
  display: inline-block;
  font-size: 13px;
  color: var(--c-accent);
  background: var(--c-index);
  padding: 4px 10px;
  margin-bottom: 14px;
  letter-spacing: 0.1em;
}

.page-about .about-honor__award-name {
  font-family: var(--font-heading);
  font-size: 20px;
  line-height: 1.25;
  color: var(--c-text);
  margin: 0 0 8px;
  letter-spacing: 0.02em;
}

.page-about .about-honor__award-desc {
  font-size: 13px;
  line-height: 1.65;
  color: var(--c-text-dim);
  margin: 0;
}

/* ===================== 延伸阅读 ===================== */
.page-about .about-cta__panel {
  background: var(--c-panel);
  border: var(--about-line);
  border-top: 3px solid var(--c-accent);
  padding: 28px 24px;
  display: grid;
  gap: 20px;
  position: relative;
}

.page-about .about-cta__panel::before {
  content: '◢';
  position: absolute;
  right: 14px;
  bottom: 10px;
  font-size: 28px;
  color: var(--c-accent-2);
  line-height: 1;
  opacity: 0.5;
}

.page-about .about-cta__title {
  font-family: var(--font-heading);
  font-size: 24px;
  line-height: 1.2;
  color: var(--c-text);
  margin: 0 0 8px;
  text-transform: uppercase;
  letter-spacing: 0.02em;
}

.page-about .about-cta__desc {
  font-size: 14px;
  line-height: 1.6;
  color: var(--c-text-dim);
  margin: 0;
}

.page-about .about-cta__links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* ===================== 响应式增强 ===================== */
@media (min-width: 768px) {
  .page-about .about-hero {
    padding: 40px 0 56px;
  }

  .page-about .about-hero__grid {
    grid-template-columns: 1fr 260px;
    gap: 40px;
    align-items: start;
    margin-top: 32px;
  }

  .page-about .about-position__grid {
    grid-template-columns: 1.6fr 1fr;
    gap: 24px;
  }

  .page-about .about-history__layout {
    grid-template-columns: 1fr 240px;
    gap: 36px;
    align-items: start;
  }

  .page-about .about-team__grid {
    grid-template-columns: 1.4fr 1fr;
    gap: 36px;
    align-items: start;
  }

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

  .page-about .about-team__media {
    grid-column: 1 / -1;
    margin-top: 4px;
  }

  .page-about .about-security__grid {
    grid-template-columns: 1.05fr 0.95fr;
    gap: 36px;
    align-items: start;
  }

  .page-about .about-honor__grid {
    grid-template-columns: 1.1fr 1fr;
    gap: 36px;
    align-items: start;
  }

  .page-about .about-cta__panel {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 28px;
    padding: 32px 36px;
  }
}

@media (min-width: 1024px) {
  .page-about .about-hero__aside {
    position: sticky;
    top: calc(var(--header-h) + 24px);
  }

  .page-about .about-history__layout {
    grid-template-columns: 1fr 280px;
    gap: 44px;
  }

  .page-about .about-history__timeline {
    padding-left: 26px;
  }

  .page-about .about-history__media {
    margin-top: 10px;
  }

  .page-about .about-team__aside {
    grid-template-columns: 1fr;
  }
}