.page-about {
  --about-gap: clamp(20px, 3vw, 40px);
  --about-cut: 16px;
  background: var(--warm);
  color: var(--ink);
  overflow-x: clip;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  background: var(--ink);
  color: var(--warm);
  padding: clamp(20px, 3vw, 34px) 0 clamp(44px, 7vw, 92px);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  right: 0;
  bottom: 0;
  width: min(42%, 460px);
  height: 6px;
  background: var(--red);
}

.page-about .about-hero .crumbs {
  color: rgba(250, 246, 239, 0.62);
}

.page-about .about-hero .crumbs a {
  color: var(--warm);
  text-decoration: none;
  border-bottom: 1px solid rgba(250, 246, 239, 0.3);
}

.page-about .about-hero .crumbs a:hover {
  border-bottom-color: var(--cyan);
}

.page-about .about-hero .eyebrow {
  color: var(--cyan);
  margin: clamp(22px, 3vw, 34px) 0 0;
}

.page-about .about-hero-grid {
  margin-top: clamp(14px, 2vw, 22px);
  display: grid;
  gap: clamp(26px, 3.4vw, 46px);
  grid-template-columns: minmax(0, 1fr);
}

@media (min-width: 940px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 1.4fr) minmax(280px, 0.6fr);
    align-items: end;
  }
}

.page-about .about-title {
  margin: 0;
  font-size: clamp(32px, 6vw, 72px);
  font-weight: 900;
  line-height: 1.04;
  letter-spacing: -0.02em;
  color: var(--warm);
  overflow-wrap: break-word;
}

.page-about .about-position {
  margin: clamp(16px, 2.2vw, 24px) 0 0;
  padding-left: 16px;
  border-left: 6px solid var(--red);
  font-size: clamp(19px, 2.4vw, 26px);
  font-weight: 700;
  line-height: 1.45;
  color: var(--cyan);
}

.page-about .about-lead {
  margin: clamp(16px, 2.2vw, 22px) 0 0;
  max-width: 62ch;
  font-size: var(--fs-18);
  line-height: 1.78;
  color: rgba(250, 246, 239, 0.8);
}

.page-about .about-tags {
  list-style: none;
  margin: clamp(20px, 2.6vw, 30px) 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .about-tags .tag {
  background: transparent;
  border: 1px solid rgba(250, 246, 239, 0.34);
  color: var(--warm);
  font-weight: 700;
  font-size: var(--fs-14);
  padding: 6px 13px;
}

.page-about .about-tags .tag--red {
  border-color: var(--red);
}

.page-about .about-tags .tag--cyan {
  border-color: var(--cyan);
  color: var(--cyan);
}

.page-about .about-tags .tag--amber {
  border-color: var(--amber);
  color: var(--amber);
}

.page-about .about-hero-stats {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--ink-2);
  border: 1px solid var(--ink-2);
}

.page-about .about-fact {
  background: var(--ink);
  padding: clamp(12px, 1.6vw, 18px);
}

.page-about .about-fact-num {
  display: block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(22px, 2.4vw, 30px);
  line-height: 1;
  color: var(--warm);
  letter-spacing: -0.01em;
}

.page-about .about-plus {
  color: var(--cyan);
}

.page-about .about-fact-label {
  display: block;
  margin-top: 8px;
  font-size: var(--fs-14);
  line-height: 1.5;
  color: rgba(250, 246, 239, 0.66);
}

/* ---------- 通用章节 ---------- */
.page-about .about-sec {
  padding: clamp(40px, 6vw, 84px) 0;
}

.page-about .sec-index {
  display: inline-block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: var(--fs-14);
  letter-spacing: 0.14em;
  color: var(--red);
  margin-bottom: 8px;
}

.page-about .sec-title {
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1.12;
}

.page-about .sec-note {
  color: var(--slate);
}

.page-about .about-body {
  display: grid;
  gap: clamp(20px, 3vw, 36px);
  grid-template-columns: minmax(0, 1fr);
  margin-top: clamp(22px, 3vw, 38px);
}

@media (min-width: 1000px) {
  .page-about .about-body--split {
    grid-template-columns: minmax(0, 1.5fr) minmax(240px, 0.7fr);
    align-items: start;
  }
}

/* ---------- 六大分类 ---------- */
.page-about .about-cats {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: clamp(12px, 1.6vw, 18px);
  grid-template-columns: minmax(0, 1fr);
}

@media (min-width: 620px) {
  .page-about .about-cats {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

.page-about .about-cat {
  position: relative;
  background: var(--paper);
  border: 1px solid var(--line);
  padding: clamp(16px, 2.2vw, 22px);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--about-cut)), calc(100% - var(--about-cut)) 100%, 0 100%);
  transition: border-color 160ms var(--ease), transform 240ms var(--ease);
}

.page-about .about-cat::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 4px;
  background: var(--red);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 160ms var(--ease);
}

.page-about .about-cat:hover,
.page-about .about-cat:focus-within {
  border-color: var(--ink);
  transform: translateY(-2px);
}

.page-about .about-cat:hover::before,
.page-about .about-cat:focus-within::before {
  transform: scaleX(1);
}

.page-about .about-cat-num {
  display: block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: var(--fs-14);
  letter-spacing: 0.1em;
  color: var(--red);
}

.page-about .about-cat h3 {
  margin: 8px 0 6px;
  font-size: var(--fs-18);
  font-weight: 900;
  color: var(--ink);
}

.page-about .about-cat p {
  margin: 0;
  font-size: var(--fs-14);
  line-height: 1.72;
  color: var(--slate);
}

.page-about .about-sys-figure {
  margin: 0;
}

.page-about .about-sys-board {
  margin-top: clamp(24px, 3.4vw, 44px);
}

.page-about .about-sys-board .board-summary {
  font-weight: 600;
}

.page-about .about-sys-board .board-cell h3 {
  margin: 0 0 6px;
  font-size: var(--fs-18);
  font-weight: 900;
  color: var(--ink);
}

.page-about .about-sys-board .board-cell p {
  margin: 0;
  font-size: var(--fs-14);
  line-height: 1.72;
  color: var(--slate);
}

/* ---------- 团队 ---------- */
.page-about .about-team-bar {
  margin-top: clamp(22px, 3vw, 38px);
  border: 1px solid var(--line);
  background: var(--paper);
  padding: 6px;
}

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

.page-about .about-team-cap {
  margin: 10px 0 0;
  font-size: var(--fs-14);
  color: var(--slate);
}

.page-about .about-team-grid {
  list-style: none;
  margin: clamp(20px, 3vw, 34px) 0 0;
  padding: 0;
  display: grid;
  gap: clamp(14px, 2vw, 24px);
  grid-template-columns: minmax(0, 1fr);
}

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

.page-about .about-team-card {
  background: var(--paper);
  border-top: 4px solid var(--ink);
  padding: clamp(16px, 2.2vw, 24px);
  transition: border-color 160ms var(--ease), background-color 160ms var(--ease);
}

.page-about .about-team-card:nth-child(1) {
  border-top-color: var(--red);
}

.page-about .about-team-card:nth-child(2) {
  border-top-color: var(--ink);
}

.page-about .about-team-card:nth-child(3) {
  border-top-color: var(--amber);
}

.page-about .about-team-card:hover {
  background: var(--warm);
}

.page-about .about-team-num {
  display: block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(30px, 3.6vw, 44px);
  line-height: 1;
  color: var(--red);
  letter-spacing: -0.02em;
}

.page-about .about-team-card h3 {
  margin: 10px 0 8px;
  font-size: var(--fs-22);
  font-weight: 900;
  color: var(--ink);
}

.page-about .about-team-card p {
  margin: 0;
  font-size: var(--fs-16);
  line-height: 1.74;
  color: var(--slate);
}

.page-about .about-team-figure {
  margin: clamp(22px, 3vw, 34px) 0 0;
}

@media (min-width: 900px) {
  .page-about .about-team-figure {
    margin-left: clamp(24px, 6vw, 96px);
  }
}

/* ---------- 发展历程 ---------- */
.page-about .about-history-figure {
  margin: clamp(22px, 3vw, 36px) 0 clamp(26px, 3.6vw, 44px);
}

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

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 10px;
  bottom: 10px;
  width: 2px;
  background: var(--line);
}

.page-about .about-tl-item {
  position: relative;
  padding: 0 0 clamp(18px, 2.6vw, 28px) clamp(30px, 4vw, 46px);
}

.page-about .about-tl-item:last-child {
  padding-bottom: 0;
}

.page-about .about-tl-item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 12px;
  width: 16px;
  height: 16px;
  background: var(--red);
  clip-path: polygon(50% 0, 100% 50%, 50% 100%, 0 50%);
}

.page-about .about-tl-item:nth-child(2)::before {
  background: var(--ink);
}

.page-about .about-tl-item:nth-child(3)::before {
  background: var(--amber);
}

.page-about .about-tl-item:nth-child(4)::before {
  background: var(--cyan-deep);
}

.page-about .about-tl-item:nth-child(5)::before {
  background: var(--slate);
}

.page-about .about-tl-item:nth-child(6)::before {
  background: var(--red-deep);
}

.page-about .about-tl-body {
  background: var(--paper);
  border: 1px solid var(--line);
  padding: clamp(14px, 2vw, 22px) clamp(16px, 2.4vw, 26px);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--about-cut)), calc(100% - var(--about-cut)) 100%, 0 100%);
}

.page-about .about-tl-item:nth-child(1) .about-tl-body,
.page-about .about-tl-item:nth-child(2) .about-tl-body {
  background: var(--ink);
  border-color: var(--ink);
}

.page-about .about-tl-item:nth-child(2) .about-tl-body {
  background: var(--ink-2);
  border-color: var(--ink-2);
}

.page-about .about-tl-item:nth-child(-n + 2) .about-tl-body h3 {
  color: var(--warm);
}

.page-about .about-tl-item:nth-child(-n + 2) .about-tl-body p {
  color: rgba(250, 246, 239, 0.78);
}

.page-about .about-tl-year {
  display: inline-block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: var(--fs-18);
  letter-spacing: 0.02em;
  color: var(--red);
  margin-bottom: 6px;
}

.page-about .about-tl-item:nth-child(-n + 2) .about-tl-year {
  color: var(--cyan);
}

.page-about .about-tl-body h3 {
  margin: 0 0 6px;
  font-size: var(--fs-18);
  font-weight: 900;
  color: var(--ink);
}

.page-about .about-tl-body p {
  margin: 0;
  font-size: var(--fs-16);
  line-height: 1.74;
  color: var(--slate);
}

/* ---------- 用户规模与生态 ---------- */
.page-about .about-stats {
  margin-top: clamp(22px, 3vw, 38px);
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

@media (min-width: 860px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.page-about .about-stat {
  background: var(--paper);
  padding: clamp(18px, 2.6vw, 28px);
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.page-about .about-stat-num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(30px, 3.8vw, 46px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--ink);
}

.page-about .about-stat-num em {
  font-style: normal;
  font-size: 0.5em;
  color: var(--red);
  margin-left: 4px;
}

.page-about .about-stat-label {
  font-size: var(--fs-14);
  line-height: 1.55;
  color: var(--slate);
}

.page-about .about-partner-lead {
  margin: clamp(22px, 3vw, 36px) 0 0;
  font-size: var(--fs-18);
  line-height: 1.7;
  color: var(--slate);
}

.page-about .about-partner-lead strong {
  font-family: var(--font-mono);
  font-size: var(--fs-22);
  font-weight: 700;
  color: var(--ink);
}

.page-about .about-partners {
  margin-top: clamp(18px, 2.4vw, 28px);
  display: grid;
  gap: clamp(14px, 2vw, 22px);
  grid-template-columns: minmax(0, 1fr);
}

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

.page-about .about-partner {
  border-top: 4px solid var(--ink);
  padding-top: 14px;
}

.page-about .about-partner:nth-child(2) {
  border-top-color: var(--red);
}

.page-about .about-partner:nth-child(3) {
  border-top-color: var(--cyan-deep);
}

.page-about .about-partner h3 {
  margin: 0 0 8px;
  font-size: var(--fs-18);
  font-weight: 900;
  color: var(--ink);
}

.page-about .about-partner p {
  margin: 0;
  font-size: var(--fs-16);
  line-height: 1.74;
  color: var(--slate);
}

.page-about .about-note {
  margin: clamp(24px, 3.4vw, 38px) 0 0;
  padding: clamp(14px, 2vw, 20px) clamp(16px, 2.4vw, 24px);
  background: var(--paper);
  border-left: 6px solid var(--amber);
  font-size: var(--fs-16);
  line-height: 1.78;
  color: var(--slate);
}

.page-about .about-note a {
  color: var(--cyan-deep);
  font-weight: 700;
  text-decoration: none;
  border-bottom: 2px solid rgba(11, 143, 134, 0.32);
}

.page-about .about-note a:hover {
  border-bottom-color: var(--cyan-deep);
}

/* ---------- 三件事 ---------- */
.page-about .about-sec--dark {
  background: var(--ink);
  color: var(--warm);
  padding-bottom: clamp(72px, 10vw, 128px);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 56px), calc(100% - 56px) 100%, 0 100%);
}

.page-about .about-sec--dark .sec-title {
  color: var(--warm);
}

.page-about .about-sec--dark .sec-note {
  color: rgba(250, 246, 239, 0.66);
}

.page-about .about-promises {
  list-style: none;
  margin: clamp(24px, 3.4vw, 40px) 0 0;
  padding: 0;
  display: grid;
  gap: clamp(18px, 2.6vw, 30px);
  grid-template-columns: minmax(0, 1fr);
}

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

.page-about .about-promise {
  border-top: 1px solid rgba(250, 246, 239, 0.22);
  padding-top: clamp(16px, 2vw, 24px);
}

.page-about .about-promise-num {
  display: block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: var(--fs-14);
  letter-spacing: 0.12em;
  color: var(--cyan);
  margin-bottom: 10px;
}

.page-about .about-promise h3 {
  margin: 0 0 8px;
  font-size: var(--fs-22);
  font-weight: 900;
  color: var(--warm);
}

.page-about .about-promise p {
  margin: 0;
  font-size: var(--fs-16);
  line-height: 1.76;
  color: rgba(250, 246, 239, 0.74);
}

.page-about .about-promise a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(22, 224, 206, 0.42);
}

.page-about .about-promise a:hover {
  border-bottom-color: var(--cyan);
}

.page-about .about-tail {
  margin: clamp(28px, 4vw, 44px) 0 0;
}

.page-about .about-tail a {
  display: inline-block;
  font-size: var(--fs-18);
  font-weight: 700;
  color: var(--cyan);
  text-decoration: none;
  padding-bottom: 3px;
  border-bottom: 3px solid rgba(22, 224, 206, 0.34);
  transition: border-color 160ms var(--ease);
}

.page-about .about-tail a:hover {
  border-bottom-color: var(--cyan);
}

/* ---------- 图片 ---------- */
.page-about .figure-frame img {
  display: block;
  width: 100%;
  height: 100%;
  max-width: 100%;
  object-fit: cover;
}

.page-about .figure-caption {
  margin-top: 10px;
  font-size: var(--fs-14);
  line-height: 1.6;
  color: var(--slate);
}

.page-about .about-sec--dark .figure-caption {
  color: rgba(250, 246, 239, 0.6);
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-cat,
  .page-about .about-cat::before,
  .page-about .about-team-card,
  .page-about .about-tail a {
    transition: none;
  }

  .page-about .about-cat:hover,
  .page-about .about-cat:focus-within {
    transform: none;
  }
}