/* ================= page: about ================= */
.page-about {
  --about-gap: clamp(58px, 8.5vw, 128px);
  --about-rule: 1px solid rgba(31, 77, 64, .85);
  display: block;
  padding-bottom: clamp(60px, 9vw, 120px);
}

/* ---------- 面包屑 ---------- */
.page-about .crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  padding-top: clamp(18px, 3vw, 30px);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--muted);
}

.page-about .crumbs a {
  color: var(--muted);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .2s var(--ease), border-color .2s var(--ease);
}

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

.page-about .crumbs__sep {
  color: var(--line);
}

.page-about .crumbs [aria-current="page"] {
  color: var(--text);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding-top: clamp(26px, 4.5vw, 54px);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  left: -8%;
  right: -8%;
  top: -8%;
  height: 64%;
  background:
    radial-gradient(58% 72% at 18% 4%, rgba(201, 162, 39, .14), transparent 68%),
    radial-gradient(46% 60% at 88% 26%, rgba(108, 156, 255, .10), transparent 70%);
  pointer-events: none;
  z-index: 0;
}

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

.page-about .about-hero__coord {
  margin: 0 0 clamp(14px, 2.2vw, 22px);
  color: var(--gold);
}

.page-about .about-hero__title {
  margin: 0 0 clamp(28px, 4.5vw, 52px);
  font-family: var(--font-display);
  font-weight: 200;
  font-size: clamp(2.3rem, 7.8vw, 5.4rem);
  line-height: 1.08;
  letter-spacing: .01em;
  color: var(--text);
  max-width: 16em;
  overflow-wrap: anywhere;
}

.page-about .about-hero__em {
  color: var(--gold);
  font-style: normal;
}

.page-about .about-hero__grid {
  align-items: start;
  row-gap: clamp(26px, 4vw, 40px);
}

.page-about .about-hero__intro .t-lede {
  color: var(--text);
}

.page-about .about-hero__note {
  margin: clamp(14px, 2vw, 20px) 0 0;
  max-width: 36em;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-hero__stats {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: var(--about-rule);
}

.page-about .about-hero__stat {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 14px;
  padding: 12px 0;
  border-bottom: var(--about-rule);
}

.page-about .about-hero__stat-num {
  font-family: var(--font-mono);
  font-size: 1.06rem;
  letter-spacing: .04em;
  color: var(--gild);
  white-space: nowrap;
}

.page-about .about-hero__stat-label {
  font-size: 12.5px;
  letter-spacing: .08em;
  color: var(--muted);
  text-align: right;
}

/* ---------- 图像容器 ---------- */
.page-about .media {
  position: relative;
  margin: 0;
  overflow: hidden;
  border-radius: var(--radius);
  background: linear-gradient(152deg, #0F2A23, #143A30);
}

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

.page-about .about-hero__media {
  margin-top: clamp(34px, 5vw, 64px);
}

/* ---------- 通用章节间距 ---------- */
.page-about .about-section {
  margin-top: var(--about-gap);
}

/* ---------- 服务对象 ---------- */
.page-about .audience-list {
  list-style: none;
  margin: clamp(26px, 3.6vw, 40px) 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: var(--about-rule);
  border-radius: var(--radius);
  overflow: hidden;
}

@media (min-width: 760px) {
  .page-about .audience-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

.page-about .audience-card {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: clamp(22px, 3vw, 32px);
  background: var(--card);
  transition: background .25s var(--ease);
}

.page-about .audience-card:hover {
  background: #164137;
}

.page-about .audience-card__tag {
  align-self: flex-start;
}

.page-about .audience-card__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 300;
  font-size: 1.15rem;
  line-height: 1.4;
  color: var(--text);
}

.page-about .audience-card__text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 三条编辑线 ---------- */
.page-about .line-list {
  list-style: none;
  margin: clamp(26px, 3.6vw, 42px) 0 0;
  padding: 0;
  display: grid;
  gap: clamp(14px, 2vw, 22px);
}

@media (min-width: 880px) {
  .page-about .line-list {
    grid-template-columns: 1.18fr 1fr .86fr;
    align-items: start;
  }
}

.page-about .line-card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: clamp(24px, 3.2vw, 38px);
  border: 1px solid var(--line);
  border-radius: 28px 28px 28px 8px;
  background: linear-gradient(158deg, #143A30, #0F2A23 78%);
  transition: transform .28s var(--ease), border-color .28s var(--ease);
}

.page-about .line-card--b {
  border-radius: 8px 28px 28px 28px;
  background: linear-gradient(158deg, #12362C, #0F2A23 82%);
}

.page-about .line-card--c {
  border-radius: 28px 8px 28px 28px;
  background: linear-gradient(158deg, #103028, #0F2A23 86%);
}

.page-about .line-card:hover,
.page-about .line-card:focus-within {
  transform: translateY(-4px);
  border-color: var(--gold);
}

.page-about .line-card__idx {
  font-size: 12px;
  letter-spacing: .2em;
  color: var(--gold);
}

.page-about .line-card__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 300;
  font-size: clamp(1.15rem, 2.2vw, 1.45rem);
  color: var(--text);
}

.page-about .line-card__text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--muted);
}

.page-about .line-card__duties {
  list-style: none;
  margin: 4px 0 0;
  padding: 12px 0 0;
  border-top: 1px solid rgba(31, 77, 64, .9);
  display: grid;
  gap: 6px;
}

.page-about .line-card__duties li {
  position: relative;
  padding-left: 16px;
  font-size: 13.5px;
  color: var(--text);
  opacity: .82;
}

.page-about .line-card__duties li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .72em;
  width: 6px;
  height: 1px;
  background: var(--gold);
}

.page-about .about-lines__media {
  margin-top: clamp(24px, 3.4vw, 40px);
}

/* ---------- 版本时间轴 ---------- */
.page-about .about-versions__grid {
  align-items: end;
  row-gap: clamp(24px, 3vw, 38px);
}

.page-about .about-versions__mediawrap {
  width: 100%;
}

.page-about .about-versions__mediawrap .media {
  border-radius: 24px 24px 8px 24px;
}

.page-about .timeline {
  position: relative;
  margin-top: clamp(30px, 4.4vw, 56px);
  display: grid;
  gap: 10px;
}

@media (min-width: 860px) {
  .page-about .timeline {
    grid-template-columns: repeat(5, minmax(0, 1fr));
    gap: clamp(12px, 1.6vw, 22px);
  }

  .page-about .timeline::before {
    content: "";
    position: absolute;
    left: 0;
    right: 0;
    top: 16px;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--line) 5%, var(--line) 95%, transparent);
    pointer-events: none;
  }
}

.page-about .tl-node {
  position: relative;
}

.page-about .tl-node__summary {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 11px 0 12px;
  cursor: pointer;
  list-style: none;
  border-bottom: 1px solid transparent;
  transition: border-color .24s var(--ease);
}

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

.page-about .tl-node__summary:hover,
.page-about .tl-node__summary:focus-visible {
  border-bottom-color: var(--gold);
}

.page-about .tl-node__dot {
  flex: 0 0 auto;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--gold);
  box-shadow: 0 0 0 5px rgba(201, 162, 39, .12);
  transition: box-shadow .24s var(--ease), background .24s var(--ease);
}

.page-about .tl-node[open] .tl-node__dot {
  background: var(--gild);
  box-shadow: 0 0 0 7px rgba(233, 206, 122, .18);
}

.page-about .tl-node__year {
  font-size: 13px;
  letter-spacing: .12em;
  color: var(--gild);
}

.page-about .tl-node__label {
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--muted);
}

.page-about .tl-node__body {
  margin-left: 4px;
  padding: 4px 0 14px 18px;
  border-left: 1px solid var(--line);
}

.page-about .tl-node__body p {
  margin: 0 0 8px;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--muted);
}

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

.page-about .tl-node--rev .tl-node__summary {
  padding-top: 9px;
}

.page-about .tl-node--rev .tl-node__dot {
  width: 14px;
  height: 14px;
  background: var(--gild);
  box-shadow: 0 0 0 7px rgba(233, 206, 122, .22);
}

.page-about .tl-node--rev .tl-node__year {
  font-size: 14px;
  color: var(--gild);
}

/* ---------- 编号索引 ---------- */
.page-about .filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: clamp(24px, 3.4vw, 38px);
}

.page-about .code-grid {
  list-style: none;
  margin: clamp(16px, 2.4vw, 24px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(74px, 1fr));
  gap: 8px;
}

.page-about .code-cell {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 54px;
  padding: 8px 6px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: linear-gradient(150deg, #143A30, #0F2A23);
  transition: border-color .22s var(--ease), transform .22s var(--ease);
}

.page-about .code-cell:hover {
  border-color: var(--gold);
  transform: translateY(-2px);
}

.page-about .code-cell__id {
  font-size: 13px;
  letter-spacing: .08em;
  color: var(--gild);
}

.page-about .code-cell[hidden] {
  display: none;
}

.page-about .filter-empty {
  margin: 16px 0 0;
  font-size: 14px;
  color: var(--muted);
}

/* ---------- 合作与跟进 ---------- */
.page-about .about-partners__body {
  padding-top: clamp(4px, 1vw, 12px);
}

.page-about .about-partners__lead {
  margin: 0 0 clamp(20px, 3vw, 30px);
  max-width: 44em;
  font-size: 16px;
  line-height: 1.85;
  color: var(--text);
}

.page-about .partner-points {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: var(--about-rule);
}

.page-about .partner-point {
  display: grid;
  grid-template-columns: minmax(96px, auto) 1fr;
  gap: clamp(12px, 2vw, 26px);
  align-items: baseline;
  padding: 15px 0;
  border-bottom: var(--about-rule);
}

.page-about .partner-point__key {
  font-size: 12.5px;
  letter-spacing: .1em;
  color: var(--gild);
  white-space: nowrap;
}

.page-about .partner-point__val {
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 更新节奏 ---------- */
.page-about .rhythm-grid {
  list-style: none;
  margin: clamp(26px, 3.6vw, 40px) 0 0;
  padding: 0;
  display: grid;
  border-top: var(--about-rule);
}

.page-about .rhythm-item {
  display: grid;
  gap: 6px;
  padding: clamp(18px, 2.4vw, 26px) 0;
  border-bottom: var(--about-rule);
}

@media (min-width: 820px) {
  .page-about .rhythm-item {
    grid-template-columns: minmax(130px, 190px) minmax(110px, 160px) 1fr;
    align-items: baseline;
    gap: clamp(16px, 2.4vw, 34px);
  }
}

.page-about .rhythm-item__num {
  font-family: var(--font-mono);
  font-size: 15px;
  letter-spacing: .04em;
  color: var(--gild);
}

.page-about .rhythm-item__title {
  margin: 0;
  font-size: 15px;
  font-weight: 500;
  letter-spacing: .06em;
  color: var(--text);
}

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

/* ---------- 延伸入口 ---------- */
.page-about .about-next__title {
  margin: 0 0 clamp(18px, 2.4vw, 26px);
  font-family: var(--font-display);
  font-weight: 300;
  color: var(--text);
}

.page-about .next-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

@media (min-width: 780px) {
  .page-about .next-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

.page-about .next-link {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: clamp(18px, 2.4vw, 26px) clamp(16px, 2vw, 24px);
  background: var(--ink);
  color: var(--text);
  text-decoration: none;
  transition: background .24s var(--ease), color .24s var(--ease);
}

.page-about .next-link:hover,
.page-about .next-link:focus-visible {
  background: var(--panel);
  color: var(--gild);
}

.page-about .next-link__idx {
  flex: 0 0 auto;
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--gold);
}

.page-about .next-link__text {
  font-size: 15px;
  line-height: 1.6;
}

/* ---------- 动效偏好 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .line-card,
  .page-about .code-cell,
  .page-about .next-link,
  .page-about .audience-card,
  .page-about .tl-node__dot {
    transition: none;
  }

  .page-about .line-card:hover,
  .page-about .line-card:focus-within,
  .page-about .code-cell:hover {
    transform: none;
  }
}