.page-about {
  --about-rail-w: 84px;
  --about-hairline: rgba(27, 51, 80, 0.85);
  color: var(--text);
  overflow-x: clip;
}

.page-about .about-visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--muted);
  padding-top: clamp(14px, 2.4vw, 24px);
}

.page-about .breadcrumbs a {
  color: var(--muted);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 180ms var(--ease-out), border-color 180ms var(--ease-out);
}

.page-about .breadcrumbs a:hover,
.page-about .breadcrumbs a:focus-visible {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

.page-about .breadcrumbs span[aria-hidden] {
  color: rgba(147, 164, 188, 0.5);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding-block: clamp(10px, 2vw, 20px) clamp(34px, 5vw, 70px);
  isolation: isolate;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  top: -10%;
  right: -18%;
  width: min(70vw, 720px);
  aspect-ratio: 1;
  background: radial-gradient(circle at 50% 50%, rgba(53, 224, 208, 0.13), rgba(14, 42, 51, 0.35) 45%, transparent 68%);
  pointer-events: none;
  z-index: -1;
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(24px, 4vw, 46px);
  margin-top: clamp(24px, 4vw, 42px);
  align-items: start;
}

@media (min-width: 920px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4.2fr);
    gap: clamp(32px, 4.5vw, 64px);
  }
}

.page-about .about-hero__main > .section-kicker {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.22em;
  color: var(--cyan);
}

.page-about .about-hero__main > .section-kicker::before {
  content: "";
  width: 26px;
  height: 1px;
  background: var(--cyan);
}

.page-about .about-hero__title {
  margin: 14px 0 0;
  font-family: var(--font-display);
  font-size: clamp(2rem, 5.2vw, 3.85rem);
  font-weight: 800;
  line-height: 1.08;
  letter-spacing: -0.02em;
  color: var(--text);
  text-wrap: balance;
}

.page-about .about-hero__lede {
  margin: clamp(18px, 2.6vw, 28px) 0 0;
  padding-left: clamp(14px, 2vw, 20px);
  border-left: 1px solid rgba(53, 224, 208, 0.42);
  max-width: 64ch;
  font-size: clamp(15px, 1.15vw, 17px);
  line-height: 1.82;
  color: var(--text);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(22px, 3vw, 34px);
}

/* ---------- 首屏速览面板 ---------- */
.page-about .about-panel {
  position: relative;
  overflow: hidden;
  padding: clamp(18px, 2.4vw, 26px);
  border-radius: var(--radius-lg);
  border: 1px solid rgba(53, 224, 208, 0.18);
  background: var(--glass);
  backdrop-filter: blur(14px);
}

.page-about .about-panel::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--cyan), transparent);
  opacity: 0.75;
}

.page-about .about-panel__label {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--cyan-soft);
}

.page-about .about-panel__list {
  list-style: none;
  margin: 14px 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  border-radius: var(--radius-md);
  overflow: hidden;
  background: rgba(27, 51, 80, 0.75);
}

.page-about .about-panel__list li {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  padding: 11px 14px;
  background: rgba(7, 14, 26, 0.62);
}

.page-about .about-panel__k {
  font-size: 14px;
  color: var(--muted);
}

.page-about .about-panel__v {
  font-family: var(--font-mono);
  font-size: 15px;
  letter-spacing: 0.04em;
  color: var(--cyan-soft);
}

.page-about .about-panel__foot {
  margin: 14px 0 0;
  font-size: 14px;
  line-height: 1.65;
  color: var(--muted);
}

/* ---------- 章节骨架 ---------- */
.page-about .about-section {
  position: relative;
  padding-block: clamp(36px, 6vw, 76px);
}

.page-about .about-section + .about-section::before {
  content: "";
  position: absolute;
  top: 0;
  left: var(--gutter);
  right: var(--gutter);
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(53, 224, 208, 0.34) 22%, rgba(53, 224, 208, 0.08) 76%, transparent);
}

.page-about .about-split {
  display: grid;
  gap: clamp(16px, 2.6vw, 28px);
}

@media (min-width: 860px) {
  .page-about .about-split {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: clamp(24px, 4vw, 56px);
  }
}

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

.page-about .about-rail__num {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.16em;
  color: var(--amber);
  border: 1px solid rgba(242, 180, 75, 0.42);
  border-radius: var(--radius-pill);
  padding: 3px 10px;
  line-height: 1.4;
}

.page-about .about-rail__word {
  font-size: 12px;
  letter-spacing: 0.24em;
  color: var(--muted);
}

@media (min-width: 860px) {
  .page-about .about-rail {
    position: sticky;
    top: 110px;
    align-self: start;
    flex-direction: column;
    align-items: flex-start;
    gap: 20px;
  }

  .page-about .about-rail__num {
    font-size: 14px;
    padding: 4px 12px;
  }

  .page-about .about-rail__word {
    writing-mode: vertical-rl;
    letter-spacing: 0.34em;
    color: var(--muted);
  }
}

.page-about .about-h2 {
  margin: 0 0 clamp(14px, 2vw, 22px);
  font-family: var(--font-display);
  font-size: clamp(1.55rem, 3vw, 2.4rem);
  font-weight: 800;
  line-height: 1.18;
  letter-spacing: -0.015em;
  color: var(--text);
  text-wrap: balance;
}

.page-about .prose {
  max-width: 68ch;
  margin: 0 0 1.05em;
  font-size: clamp(15px, 1.1vw, 17px);
  line-height: 1.82;
  color: var(--text);
}

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

.page-about .about-sec-head {
  max-width: 76ch;
  margin-bottom: clamp(22px, 3.4vw, 40px);
}

.page-about .about-sec-head__lede {
  max-width: 62ch;
  color: var(--muted);
}

/* ---------- 图像 ---------- */
.page-about .about-figure {
  margin: 0 0 clamp(18px, 3vw, 30px);
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--line);
  background: var(--ink-900);
}

.page-about .about-figure img,
.page-about .about-coverage__figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .media-caption {
  padding: 10px 14px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--muted);
  background: var(--ink-900);
  border-top: 1px solid rgba(27, 51, 80, 0.9);
}

.page-about .about-section:nth-of-type(4) .about-figure {
  margin: clamp(26px, 4vw, 44px) 0 0;
}

/* ---------- 时间线 ---------- */
.page-about .about-trace {
  display: block;
  width: 100%;
  height: 42px;
  margin: 0 0 6px;
  color: var(--cyan);
}

.page-about .about-timeline {
  display: grid;
  gap: 14px;
  margin-top: clamp(12px, 2vw, 20px);
}

.page-about .about-node {
  position: relative;
  padding: 18px 18px 18px 24px;
  border-radius: var(--radius-md);
  background: var(--panel);
  border-left: 1px solid rgba(53, 224, 208, 0.3);
  outline: none;
  transition: transform 220ms var(--ease-out), border-color 220ms var(--ease-out), background 220ms var(--ease-out);
}

.page-about .about-node:hover,
.page-about .about-node:focus {
  border-left-color: var(--cyan);
  background: linear-gradient(180deg, rgba(53, 224, 208, 0.06), transparent 60%), var(--panel);
  transform: translateY(-2px);
}

.page-about .about-node:focus-visible {
  box-shadow: 0 0 0 2px rgba(53, 224, 208, 0.55);
}

.page-about .about-node__dot {
  position: absolute;
  left: -5px;
  top: 24px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 0 4px rgba(53, 224, 208, 0.14);
}

.page-about .about-node__year {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--amber);
}

.page-about .about-node__title {
  margin: 0 0 8px;
  font-size: 1.03rem;
  font-weight: 700;
  line-height: 1.4;
  color: var(--text);
}

.page-about .about-node__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.74;
  color: var(--muted);
}

.page-about .about-node__more {
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  margin: 0;
  border-top: 1px solid transparent;
  font-size: 14px;
  line-height: 1.74;
  color: var(--cyan-soft);
  transition: max-height 300ms var(--ease-out), opacity 200ms var(--ease-out), margin 300ms var(--ease-out), padding 300ms var(--ease-out);
}

.page-about .about-node:hover .about-node__more,
.page-about .about-node:focus .about-node__more,
.page-about .about-node:focus-within .about-node__more {
  max-height: 10em;
  opacity: 1;
  margin-top: 10px;
  padding-top: 10px;
  border-top-color: rgba(53, 224, 208, 0.22);
}

@media (min-width: 900px) {
  .page-about .about-timeline {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 18px;
    align-items: start;
  }

  .page-about .about-node:nth-child(2) {
    margin-top: 26px;
  }

  .page-about .about-node:nth-child(3) {
    margin-top: 52px;
  }

  .page-about .about-node:nth-child(4) {
    margin-top: 78px;
  }
}

/* ---------- 数据带 ---------- */
.page-about .about-stats {
  display: grid;
  gap: 1px;
  overflow: hidden;
  border-radius: var(--radius-lg);
  border: 1px solid var(--line);
  background: rgba(27, 51, 80, 0.75);
}

@media (min-width: 660px) {
  .page-about .about-stats {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 1040px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.page-about .about-stat {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: clamp(18px, 2.6vw, 30px);
  background: var(--panel);
}

.page-about .about-stat .stat__value {
  font-family: var(--font-mono);
  font-size: clamp(1.65rem, 3.1vw, 2.45rem);
  line-height: 1;
  letter-spacing: 0.01em;
  color: var(--cyan-soft);
}

.page-about .about-stat .stat__label {
  font-size: 14px;
  line-height: 1.66;
  color: var(--muted);
}

/* ---------- 多端覆盖 ---------- */
.page-about .about-coverage {
  display: grid;
  gap: clamp(20px, 3vw, 32px);
  align-items: center;
  margin-top: clamp(26px, 4vw, 46px);
}

@media (min-width: 840px) {
  .page-about .about-coverage {
    grid-template-columns: minmax(0, 5fr) minmax(0, 6fr);
    gap: clamp(26px, 4vw, 56px);
  }
}

.page-about .about-coverage__figure {
  margin: 0;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--line);
  background: var(--ink-900);
}

.page-about .about-coverage__body h3 {
  margin: 0 0 14px;
  font-family: var(--font-display);
  font-size: clamp(1.15rem, 1.9vw, 1.45rem);
  font-weight: 700;
  line-height: 1.35;
  color: var(--text);
}

.page-about .about-coverage__body .prose {
  color: var(--muted);
  font-size: 15px;
}

/* ---------- 运营机制清单 ---------- */
.page-about .about-mech {
  list-style: none;
  margin: clamp(18px, 2.6vw, 26px) 0 0;
  padding: 0;
}

.page-about .about-mech li {
  position: relative;
  padding: 14px 0 14px 26px;
  border-top: 1px solid var(--about-hairline);
  font-size: 15px;
  line-height: 1.76;
  color: var(--text);
}

.page-about .about-mech li:last-child {
  border-bottom: 1px solid var(--about-hairline);
}

.page-about .about-mech li::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 24px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--cyan);
}

/* ---------- 版本节奏 ---------- */
.page-about .about-rhythm {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-rhythm li {
  display: grid;
  gap: 6px;
  padding: clamp(16px, 2.4vw, 24px) 0;
  border-top: 1px solid var(--about-hairline);
}

.page-about .about-rhythm li:last-child {
  border-bottom: 1px solid var(--about-hairline);
}

@media (min-width: 760px) {
  .page-about .about-rhythm li {
    grid-template-columns: 150px minmax(0, 1fr);
    gap: clamp(18px, 3vw, 44px);
    align-items: baseline;
  }
}

.page-about .about-rhythm__num {
  font-family: var(--font-mono);
  font-size: clamp(1.1rem, 2vw, 1.5rem);
  line-height: 1.2;
  letter-spacing: 0.02em;
  color: var(--amber);
}

.page-about .about-rhythm__body h3 {
  margin: 0 0 6px;
  font-size: 1.02rem;
  font-weight: 700;
  line-height: 1.45;
  color: var(--text);
}

.page-about .about-rhythm__body p {
  margin: 0;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.78;
  color: var(--muted);
}

/* ---------- 协作生态 ---------- */
.page-about .about-eco {
  margin-top: clamp(18px, 2.6vw, 28px);
  border-top: 1px solid var(--about-hairline);
}

.page-about .about-eco__item {
  padding: clamp(16px, 2.2vw, 22px) 0 clamp(16px, 2.2vw, 22px) 18px;
  border-bottom: 1px solid var(--about-hairline);
  border-left: 1px solid rgba(53, 224, 208, 0.18);
  outline: none;
  transition: border-left-color 200ms var(--ease-out), padding-left 200ms var(--ease-out);
}

.page-about .about-eco__item:hover,
.page-about .about-eco__item:focus {
  border-left-color: var(--cyan);
  padding-left: 24px;
}

.page-about .about-eco__item:focus-visible {
  box-shadow: 0 0 0 2px rgba(53, 224, 208, 0.45);
  border-radius: var(--radius-sm);
}

.page-about .about-eco__item h3 {
  margin: 0 0 6px;
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.45;
  color: var(--text);
}

.page-about .about-eco__item > p {
  margin: 0;
  max-width: 66ch;
  font-size: 15px;
  line-height: 1.76;
  color: var(--muted);
}

.page-about .about-eco__item > .about-eco__more {
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  color: var(--cyan-soft);
  transition: max-height 280ms var(--ease-out), opacity 200ms var(--ease-out), margin 280ms var(--ease-out);
}

.page-about .about-eco__item:hover > .about-eco__more,
.page-about .about-eco__item:focus > .about-eco__more,
.page-about .about-eco__item:focus-within > .about-eco__more {
  max-height: 6em;
  opacity: 1;
  margin-top: 8px;
}

/* ---------- 收束 ---------- */
.page-about .about-closing {
  position: relative;
  padding-block: clamp(36px, 6vw, 76px) clamp(44px, 7vw, 88px);
}

.page-about .about-quote {
  margin: 0;
  max-width: 74ch;
  padding: clamp(18px, 3vw, 30px) clamp(16px, 3vw, 30px) clamp(18px, 3vw, 30px) clamp(18px, 3vw, 30px);
  border-left: 2px solid var(--cyan);
  background: linear-gradient(90deg, rgba(53, 224, 208, 0.07), transparent 72%);
}

.page-about .about-quote p {
  margin: 0;
  font-size: clamp(16px, 1.6vw, 20px);
  line-height: 1.74;
  color: var(--text);
}

.page-about .about-quote footer {
  margin-top: 14px;
  font-family: var(--font-mono);
  font-size: 14px;
  letter-spacing: 0.1em;
  color: var(--muted);
}

.page-about .about-quote cite {
  font-style: normal;
}

.page-about .about-next {
  display: grid;
  gap: 1px;
  margin-top: clamp(28px, 4vw, 44px);
  overflow: hidden;
  border-radius: var(--radius-lg);
  border: 1px solid var(--line);
  background: rgba(27, 51, 80, 0.75);
}

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

.page-about .about-next__link {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: clamp(16px, 2.4vw, 24px);
  background: var(--ink-900);
  text-decoration: none;
  transition: background 200ms var(--ease-out);
}

.page-about .about-next__link:hover,
.page-about .about-next__link:focus-visible {
  background: var(--panel);
}

.page-about .about-next__label {
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text);
  transition: color 180ms var(--ease-out);
}

.page-about .about-next__link:hover .about-next__label,
.page-about .about-next__link:focus-visible .about-next__label {
  color: var(--cyan);
}

.page-about .about-next__desc {
  font-size: 14px;
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 无障碍与动效降级 ---------- */
.page-about a:focus-visible,
.page-about [tabindex]:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-node,
  .page-about .about-eco__item,
  .page-about .about-next__link {
    transition-duration: 1ms;
  }

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

  .page-about .about-node__more,
  .page-about .about-eco__item > .about-eco__more {
    max-height: none;
    opacity: 1;
    margin-top: 10px;
    padding-top: 10px;
    border-top-color: rgba(53, 224, 208, 0.22);
    transition: none;
  }
}