.page-about {
  --about-line: rgba(26, 26, 46, 0.13);
  --about-grid: rgba(26, 26, 46, 0.06);
  --about-gold-line: rgba(212, 160, 23, 0.55);
  background-color: var(--paper);
  color: var(--char);
}

.page-about .about-crumb {
  padding-top: calc(var(--header-h) + 16px);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  padding-bottom: clamp(28px, 5vw, 56px);
  overflow: hidden;
  background-image:
    repeating-linear-gradient(to right, var(--about-grid) 0 1px, transparent 1px 74px),
    repeating-linear-gradient(to bottom, var(--about-grid) 0 1px, transparent 1px 74px);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  z-index: -1;
  top: -40px;
  right: 0;
  width: min(56%, 620px);
  height: 68%;
  background: linear-gradient(150deg, rgba(200, 16, 46, 0.14), rgba(212, 160, 23, 0.18));
  clip-path: polygon(28% 0, 100% 0, 100% 100%, 0 100%);
  pointer-events: none;
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(22px, 4vw, 44px);
  align-items: start;
  padding-top: clamp(14px, 2.4vw, 26px);
}

.page-about .about-hero__copy h1 {
  margin: 12px 0 16px;
  font-size: clamp(30px, 5vw, 50px);
  font-weight: 900;
  line-height: 1.16;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.page-about .about-hero__copy .lede {
  max-width: 46ch;
  font-size: clamp(15.5px, 1.7vw, 19px);
  line-height: 1.8;
  color: var(--char);
}

.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  margin: 24px 0 22px;
  background: var(--about-line);
  border-block: 1px solid var(--about-line);
}

.page-about .hs {
  display: grid;
  gap: 4px;
  padding: 13px 10px;
  background: var(--paper);
}

.page-about .hs__num {
  font-family: var(--font-mono);
  font-size: clamp(19px, 2.6vw, 27px);
  font-weight: 700;
  line-height: 1.1;
  color: var(--red);
}

.page-about .hs__num em {
  margin-left: 2px;
  font-style: normal;
  font-size: 12px;
  font-weight: 500;
  color: var(--char);
}

.page-about .hs__lb {
  font-size: 12.5px;
  line-height: 1.5;
  color: var(--char);
}

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

.page-about .about-hero__figure {
  position: relative;
  margin: 0;
}

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

.page-about .about-hero__figure .media-caption {
  margin-top: 8px;
  font-size: 12.5px;
  color: var(--char);
}

/* ---------- 主体布局 ---------- */
.page-about .about-layout {
  display: grid;
  gap: 22px;
  max-width: var(--w-max);
  margin-inline: auto;
  padding-inline: var(--gutter);
  padding-top: clamp(24px, 4vw, 46px);
  padding-bottom: clamp(38px, 6vw, 76px);
}

.page-about .about-toc {
  border-top: 2px solid var(--ink);
  padding-top: 10px;
}

.page-about .about-toc__title {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--red);
}

.page-about .about-toc ul {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0 0 8px;
  list-style: none;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-toc a {
  display: inline-block;
  white-space: nowrap;
  padding: 7px 12px;
  font-size: 13.5px;
  color: var(--char);
  text-decoration: none;
  background: var(--paper);
  border: 1px solid var(--about-line);
  transition: border-color var(--speed) ease, color var(--speed) ease;
}

.page-about .about-toc a:hover,
.page-about .about-toc a:focus-visible {
  color: var(--red);
  border-color: var(--red);
}

/* ---------- 章节 ---------- */
.page-about .about-sec {
  padding-block: clamp(24px, 4vw, 46px);
  border-top: 1px solid var(--about-line);
}

.page-about .about-sec:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .about-sec__head {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 10px 14px;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--about-line);
}

.page-about .about-sec__num {
  font-family: var(--font-mono);
  font-size: clamp(26px, 4vw, 38px);
  font-weight: 700;
  line-height: 1;
  color: rgba(200, 16, 46, 0.3);
}

.page-about .about-sec__title {
  margin: 0;
  font-size: clamp(21px, 2.8vw, 30px);
  font-weight: 900;
  line-height: 1.3;
  color: var(--ink);
}

.page-about .about-sec p {
  max-width: 62ch;
  margin: 0 0 14px;
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.85;
  color: var(--char);
}

.page-about .origin-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 18px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .origin-tags .tag {
  display: inline-block;
  padding: 5px 12px;
  font-size: 13px;
  color: var(--ink);
  background: var(--mist);
  border-left: 3px solid var(--gold);
}

/* ---------- 四步流程 ---------- */
.page-about .flow {
  display: grid;
  gap: 1px;
  margin: 22px 0 18px;
  padding: 0;
  list-style: none;
  background: var(--about-line);
  border: 1px solid var(--about-line);
}

.page-about .flow__item {
  padding: 18px 16px;
  background: var(--paper);
}

.page-about .flow__idx {
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--jade-deep);
}

.page-about .flow__item h3 {
  margin: 0 0 8px;
  font-size: 20px;
  font-weight: 900;
  color: var(--ink);
}

.page-about .flow__item p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.75;
}

.page-about .flow-note {
  padding-left: 14px;
  border-left: 3px solid var(--red);
  font-size: 14.5px !important;
  color: var(--ink) !important;
}

/* ---------- 时间轴 ---------- */
.page-about .timeline {
  display: grid;
  gap: 16px;
  margin-top: 22px;
}

.page-about .tl-card {
  position: relative;
  padding: 22px 18px 18px;
  background: var(--mist);
  clip-path: polygon(0 0, calc(100% - 14px) 0, 100% 14px, 100% 100%, 0 100%);
}

.page-about .tl-card::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 4px;
  background: var(--jade);
}

.page-about .tl-card--now::before {
  background: var(--gold);
}

.page-about .tl-card__ver {
  margin: 0 0 8px !important;
  font-family: var(--font-mono);
  font-size: 13px !important;
  letter-spacing: 0.16em;
  color: var(--red) !important;
}

.page-about .tl-card--now .tl-card__ver {
  color: var(--red-deep) !important;
}

.page-about .tl-card h3 {
  margin: 0 0 10px;
  font-size: 19px;
  font-weight: 900;
  line-height: 1.4;
  color: var(--ink);
}

.page-about .tl-card p {
  margin: 0 0 10px;
  font-size: 14.5px;
  line-height: 1.78;
}

.page-about .tl-card details {
  border-top: 1px dashed var(--about-gold-line);
  padding-top: 10px;
}

.page-about .tl-card summary {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  cursor: pointer;
  list-style: none;
  font-size: 13.5px;
  font-weight: 700;
  color: var(--jade-deep);
}

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

.page-about .tl-card summary::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 15px;
  color: var(--red);
}

.page-about .tl-card details[open] summary::after {
  content: "−";
}

.page-about .tl-card details p {
  margin: 10px 0 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--char);
}

/* ---------- 团队与准入 ---------- */
.page-about .team-grid {
  display: grid;
  gap: 20px;
  margin-bottom: 22px;
}

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

.page-about .team-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border-left: 4px solid var(--red);
}

.page-about .team-figure .media-caption {
  margin-top: 8px;
  font-size: 12.5px;
  color: var(--char);
}

.page-about .gate-list {
  display: grid;
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: gate;
}

.page-about .gate {
  padding: 16px 16px 14px;
  background: var(--paper);
  border: 1px solid var(--about-line);
  border-left: 3px solid var(--jade);
}

.page-about .gate__idx {
  display: block;
  margin-bottom: 6px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.16em;
  color: var(--jade-deep);
}

.page-about .gate h3 {
  margin: 0 0 6px;
  font-size: 17px;
  font-weight: 900;
  color: var(--ink);
}

.page-about .gate p {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
}

/* ---------- 覆盖 ---------- */
.page-about .cover-band {
  padding: clamp(18px, 3vw, 28px);
  background: var(--mist);
  border-left: 4px solid var(--jade);
}

.page-about .cover-band p {
  margin-bottom: 18px;
  color: var(--ink);
}

.page-about .cover-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .cover-stats li {
  display: grid;
  gap: 2px;
}

.page-about .cover-stats__num {
  font-family: var(--font-mono);
  font-size: clamp(22px, 3vw, 30px);
  font-weight: 700;
  line-height: 1.1;
  color: var(--red);
}

.page-about .cover-stats__lb {
  font-size: 12.5px;
  color: var(--char);
}

.page-about .cover-figure {
  margin: 22px 0 18px;
}

.page-about .cover-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border-top: 1px solid var(--about-line);
  border-bottom: 3px solid var(--gold);
}

.page-about .cover-figure .media-caption {
  margin-top: 8px;
  font-size: 12.5px;
  color: var(--char);
}

/* ---------- 原则（深色收束） ---------- */
.page-about .about-principles {
  position: relative;
  overflow: hidden;
  padding-block: clamp(36px, 6vw, 76px);
  background: var(--ink);
  color: var(--paper);
}

.page-about .about-principles::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    repeating-linear-gradient(to right, rgba(245, 241, 232, 0.06) 0 1px, transparent 1px 88px),
    repeating-linear-gradient(to bottom, rgba(245, 241, 232, 0.06) 0 1px, transparent 1px 88px);
  pointer-events: none;
}

.page-about .about-principles::after {
  content: "";
  position: absolute;
  right: -12%;
  bottom: -28%;
  width: min(74%, 760px);
  height: 460px;
  background: repeating-radial-gradient(circle at 72% 100%, rgba(212, 160, 23, 0.2) 0 1px, transparent 1px 26px);
  pointer-events: none;
}

.page-about .principles-inner {
  position: relative;
  z-index: 1;
  max-width: var(--w-max);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.page-about .principles-head {
  max-width: 58ch;
  margin-bottom: clamp(24px, 4vw, 40px);
}

.page-about .about-sec__num--light {
  color: rgba(212, 160, 23, 0.65);
}

.page-about .principles-head h2 {
  margin: 8px 0 12px;
  font-size: clamp(24px, 3.4vw, 36px);
  font-weight: 900;
  line-height: 1.25;
  color: var(--paper);
}

.page-about .principles-head p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.8;
  color: rgba(245, 241, 232, 0.82);
}

.page-about .principles-list {
  display: grid;
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  background: rgba(245, 241, 232, 0.18);
}

.page-about .principles-list li {
  padding: 20px 18px;
  background: var(--ink);
  border-top: 3px solid var(--red);
}

.page-about .principles-list li:nth-child(2) {
  border-top-color: var(--gold);
}

.page-about .principles-list li:nth-child(3) {
  border-top-color: var(--jade);
}

.page-about .principles-list h3 {
  margin: 0 0 8px;
  font-size: 18px;
  font-weight: 900;
  color: var(--paper);
}

.page-about .principles-list p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: rgba(245, 241, 232, 0.8);
}

/* ---------- 结尾 ---------- */
.page-about .about-close {
  position: relative;
  padding-block: clamp(34px, 5vw, 64px);
  background: var(--paper);
  border-top: 4px solid var(--gold);
}

.page-about .about-close__inner {
  max-width: var(--w-max);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.page-about .about-close h2 {
  margin: 8px 0 12px;
  font-size: clamp(23px, 3.2vw, 34px);
  font-weight: 900;
  line-height: 1.28;
  color: var(--ink);
}

.page-about .about-close p {
  max-width: 56ch;
  margin: 0 0 20px;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--char);
}

.page-about .about-close__actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
}

.page-about .about-close__link {
  font-size: 14px;
  color: var(--jade-deep);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .about-close__link:hover,
.page-about .about-close__link:focus-visible {
  color: var(--red);
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .cover-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 760px) {
  .page-about .flow {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .gate-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 860px) {
  .page-about .team-grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    align-items: center;
    gap: 26px;
  }

  .page-about .principles-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
  }

  .page-about .about-hero__copy h1 {
    transform: skewX(-3deg);
    transform-origin: left bottom;
  }

  .page-about .flow {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .timeline {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    align-items: start;
    gap: 20px;
  }

  .page-about .tl-card:nth-child(2) {
    margin-top: 40px;
  }

  .page-about .tl-card:nth-child(3) {
    margin-top: 80px;
  }
}

@media (min-width: 1024px) {
  .page-about .about-layout {
    grid-template-columns: minmax(0, 1fr) 188px;
    align-items: start;
    gap: 40px;
  }

  .page-about .about-main {
    grid-column: 1;
    grid-row: 1;
  }

  .page-about .about-toc {
    grid-column: 2;
    grid-row: 1;
    position: sticky;
    top: calc(var(--header-h) + 24px);
    border-top-width: 2px;
  }

  .page-about .about-toc ul {
    flex-direction: column;
    gap: 2px;
    overflow: visible;
  }

  .page-about .about-toc a {
    display: block;
    padding: 8px 0 8px 10px;
    border: 0;
    border-left: 2px solid var(--about-line);
    font-size: 13.5px;
  }

  .page-about .about-toc a:hover,
  .page-about .about-toc a:focus-visible {
    border-left-color: var(--red);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-hero__copy h1 {
    transform: none;
  }

  .page-about .about-toc a {
    transition: none;
  }
}