.page-about {
  --about-pad: clamp(20px, 5vw, 72px);
  --about-rail-w: 112px;
  background: var(--ink-900);
  color: var(--text-dark);
  font-family: var(--font-body);
  font-size: 16.5px;
  line-height: 1.8;
  min-width: 0;
}

/* ---------- 骨架：窄屏单列，桌面端侧轨 + 内容 ---------- */
.page-about .about-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  min-width: 0;
}

.page-about .about-flow {
  min-width: 0;
}

/* ---------- 章节索引轨 ---------- */
.page-about .rail {
  position: sticky;
  top: 0;
  z-index: 30;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 16px;
  overflow-x: auto;
  background: rgba(6, 17, 15, 0.95);
  border-bottom: 1px solid rgba(43, 227, 198, 0.16);
  scrollbar-width: none;
}

.page-about .rail::-webkit-scrollbar {
  display: none;
}

.page-about .rail__tag {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.12em;
  color: var(--mist-400);
  padding-right: 10px;
  margin-right: 2px;
  border-right: 1px solid rgba(110, 138, 132, 0.4);
}

.page-about .rail__link {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  padding: 7px 14px;
  border-radius: var(--radius-pill);
  border: 1px solid rgba(43, 227, 198, 0.26);
  color: var(--text-dark);
  font-size: 13px;
  line-height: 1.2;
  text-decoration: none;
  white-space: nowrap;
  transition: background-color 0.18s var(--ease), color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.page-about .rail__link:hover {
  background: var(--cyan-500);
  border-color: var(--cyan-500);
  color: var(--ink-900);
}

@media (min-width: 1024px) {
  .page-about .about-shell {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
  }

  .page-about .rail {
    position: sticky;
    top: 96px;
    align-self: start;
    flex-direction: column;
    align-items: stretch;
    gap: 6px;
    padding: 36px 14px 36px 18px;
    overflow: visible;
    background: transparent;
    border-bottom: 0;
    border-right: 1px solid rgba(43, 227, 198, 0.14);
  }

  .page-about .rail__tag {
    padding: 0 4px 12px;
    margin: 0 0 8px;
    border-right: 0;
    border-bottom: 1px solid rgba(110, 138, 132, 0.28);
  }

  .page-about .rail__link {
    justify-content: flex-start;
    padding: 8px 10px;
    border: 0;
    border-left: 2px solid transparent;
    border-radius: 0 var(--radius-s) var(--radius-s) 0;
    white-space: normal;
    font-size: 12.5px;
    line-height: 1.45;
  }

  .page-about .rail__link:hover {
    background: rgba(43, 227, 198, 0.1);
    border-left-color: var(--cyan-600);
    color: var(--cyan-500);
  }

  .page-about .rail__link[aria-current="true"] {
    background: rgba(43, 227, 198, 0.13);
    border-left-color: var(--cyan-500);
    color: var(--cyan-500);
  }
}

/* ---------- 首屏 ---------- */
.page-about .hero {
  position: relative;
  overflow: hidden;
  padding: 30px var(--about-pad) 56px;
  background: linear-gradient(158deg, #06110F 0%, #0C1F1B 52%, #13302A 100%);
}

.page-about .hero::after {
  content: "";
  position: absolute;
  right: -150px;
  top: -130px;
  width: 420px;
  height: 420px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(43, 227, 198, 0.2) 0%, rgba(43, 227, 198, 0) 70%);
  pointer-events: none;
}

.page-about .breadcrumb {
  position: relative;
  z-index: 1;
}

.page-about .breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0 0 22px;
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--mist-400);
}

.page-about .breadcrumb__item a {
  color: var(--cyan-500);
  text-decoration: none;
}

.page-about .breadcrumb__item a:hover {
  text-decoration: underline;
}

.page-about .breadcrumb__item + .breadcrumb__item::before {
  content: "/";
  margin-right: 8px;
  color: rgba(110, 138, 132, 0.7);
}

.page-about .hero__eyebrow {
  position: relative;
  z-index: 1;
  margin: 0 0 16px;
}

.page-about .hero__title {
  position: relative;
  z-index: 1;
  margin: 0 0 20px;
  max-width: 22ch;
  font-family: var(--font-title);
  font-weight: 900;
  font-size: clamp(2rem, 5.6vw, 3.5rem);
  line-height: 1.13;
  letter-spacing: -0.025em;
  color: var(--text-dark);
}

.page-about .hero__lede {
  position: relative;
  z-index: 1;
  margin: 0 0 36px;
  max-width: 64ch;
  font-size: 1rem;
  color: rgba(234, 247, 243, 0.82);
}

.page-about .hero__facts {
  position: relative;
  z-index: 1;
  display: flex;
  flex-wrap: wrap;
  gap: 18px 40px;
  margin: 0;
  padding: 24px 0 0;
  list-style: none;
  border-top: 1px solid rgba(43, 227, 198, 0.2);
}

.page-about .hero__facts li {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding-left: 14px;
  border-left: 2px solid rgba(43, 227, 198, 0.45);
}

.page-about .fact__num {
  font-family: var(--font-mono);
  font-size: 1.55rem;
  font-weight: 700;
  line-height: 1.1;
  color: var(--cyan-500);
}

.page-about .fact__label {
  font-size: 0.82rem;
  letter-spacing: 0.02em;
  color: var(--mist-400);
}

/* ---------- 章节通用 ---------- */
.page-about .sec {
  position: relative;
}

.page-about .sec::before {
  content: "";
  display: block;
  height: 5px;
  background: var(--grad-band);
  opacity: 0.55;
}

.page-about .sec--light {
  background: var(--paper-50);
  color: var(--text-light);
}

.page-about .sec--light::before {
  background: var(--grad-band-rev);
  opacity: 0.8;
}

.page-about .sec--dark {
  background: var(--ink-800);
  color: var(--text-dark);
}

.page-about .sec__inner {
  padding: 52px var(--about-pad) 64px;
  max-width: 1360px;
  margin: 0 auto;
}

.page-about .sec__lede {
  margin: 0 0 12px;
  max-width: 70ch;
  font-size: 0.98rem;
}

.page-about .sec--light .sec__lede {
  color: rgba(27, 43, 39, 0.76);
}

.page-about .sec--dark .sec__lede {
  color: rgba(234, 247, 243, 0.78);
}

.page-about .ch-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 14px;
  margin: 0 0 20px;
}

.page-about .ch-num {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.14em;
  padding: 3px 9px;
  border-radius: var(--radius-xs);
  border: 1px solid rgba(43, 227, 198, 0.45);
  color: var(--cyan-500);
}

.page-about .sec--light .ch-num {
  border-color: rgba(20, 98, 79, 0.35);
  color: var(--jade-600);
}

.page-about .ch-title {
  margin: 0;
  font-family: var(--font-title);
  font-weight: 800;
  font-size: clamp(1.4rem, 3.1vw, 2.05rem);
  line-height: 1.25;
  letter-spacing: -0.022em;
}

/* ---------- 01 场景清单 ---------- */
.page-about .scene-list {
  margin: 30px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .scene {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 4px 16px;
  padding: 20px 0;
  border-top: 1px solid rgba(27, 43, 39, 0.13);
}

.page-about .scene:last-child {
  border-bottom: 1px solid rgba(27, 43, 39, 0.13);
}

.page-about .scene__idx {
  grid-row: 1 / span 2;
  padding-top: 5px;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  letter-spacing: 0.08em;
  color: var(--jade-600);
}

.page-about .scene__name {
  margin: 0;
  font-family: var(--font-title);
  font-size: 1.06rem;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.page-about .scene__desc {
  margin: 0;
  max-width: 68ch;
  font-size: 0.95rem;
  color: rgba(27, 43, 39, 0.72);
}

/* ---------- 02 版本时间轴 ---------- */
.page-about .ver-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 34px;
  margin-top: 26px;
}

@media (min-width: 940px) {
  .page-about .ver-layout {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    gap: 48px;
    align-items: start;
  }
}

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

.page-about .ver {
  position: relative;
  padding: 0 0 16px 26px;
}

.page-about .ver::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 20px;
  bottom: -4px;
  width: 1px;
  background: linear-gradient(180deg, rgba(43, 227, 198, 0.65), rgba(43, 227, 198, 0.06));
}

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

.page-about .ver:last-child::before {
  display: none;
}

.page-about .ver::after {
  content: "";
  position: absolute;
  left: 0;
  top: 15px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--ink-800);
  border: 2px solid var(--cyan-500);
}

.page-about .ver__box {
  border: 1px solid rgba(43, 227, 198, 0.18);
  border-radius: var(--radius-m);
  background: rgba(19, 48, 42, 0.68);
  overflow: hidden;
  transition: border-color 0.2s var(--ease);
}

.page-about .ver__box[open] {
  border-color: rgba(43, 227, 198, 0.48);
}

.page-about .ver__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
  padding: 14px 18px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .ver__head::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 1rem;
  color: var(--cyan-500);
}

.page-about .ver__box[open] .ver__head::after {
  content: "−";
}

.page-about .ver__num {
  font-family: var(--font-mono);
  font-size: 0.95rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--cyan-500);
}

.page-about .ver__year {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  padding: 2px 8px;
  border-radius: var(--radius-xs);
  border: 1px solid rgba(110, 138, 132, 0.42);
  color: var(--mist-400);
}

.page-about .ver__name {
  flex: 1 1 auto;
  min-width: 0;
  font-family: var(--font-title);
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.page-about .ver__body {
  margin: 0;
  padding: 0 18px 18px;
  font-size: 0.92rem;
  color: rgba(234, 247, 243, 0.78);
}

/* ---------- 03 团队分工 ---------- */
.page-about .role-list {
  margin: 28px 0 40px;
  padding: 0;
  list-style: none;
}

.page-about .role {
  display: grid;
  gap: 10px;
  padding: 20px 0;
  border-bottom: 1px solid rgba(20, 98, 79, 0.15);
}

.page-about .role:first-child {
  border-top: 1px solid rgba(20, 98, 79, 0.15);
}

.page-about .role__tag {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
}

.page-about .role__idx {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  padding: 3px 9px;
  border-radius: var(--radius-pill);
  background: var(--jade-600);
  color: var(--paper-50);
}

.page-about .role__name {
  font-family: var(--font-title);
  font-size: 1.1rem;
  font-weight: 800;
  letter-spacing: -0.01em;
}

.page-about .role__count {
  font-family: var(--font-mono);
  font-size: 0.76rem;
  padding: 3px 10px;
  border-radius: var(--radius-pill);
  border: 1px solid rgba(20, 98, 79, 0.35);
  color: var(--jade-600);
}

.page-about .role__desc {
  margin: 0;
  max-width: 72ch;
  font-size: 0.95rem;
  color: rgba(27, 43, 39, 0.76);
}

/* ---------- 04 更新节奏 ---------- */
.page-about .cadence-list {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin: 26px 0 36px;
  padding: 0;
  list-style: none;
}

@media (min-width: 720px) {
  .page-about .cadence-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px;
  }
}

.page-about .cadence {
  padding: 20px 22px 22px;
  border-radius: var(--radius-l);
  background: rgba(19, 48, 42, 0.72);
  border: 1px solid rgba(43, 227, 198, 0.16);
  transition: border-color 0.2s var(--ease), background-color 0.2s var(--ease);
}

.page-about .cadence:hover {
  border-color: rgba(43, 227, 198, 0.42);
  background: rgba(19, 48, 42, 0.95);
}

.page-about .cadence__freq {
  display: inline-block;
  margin-bottom: 12px;
  padding: 3px 11px;
  border-radius: var(--radius-pill);
  border: 1px solid rgba(43, 227, 198, 0.42);
  background: rgba(43, 227, 198, 0.14);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  color: var(--cyan-500);
}

.page-about .cadence__name {
  margin: 0 0 6px;
  font-family: var(--font-title);
  font-size: 1.03rem;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.page-about .cadence__desc {
  margin: 0;
  font-size: 0.92rem;
  color: rgba(234, 247, 243, 0.76);
}

/* ---------- 05 订阅 ---------- */
.page-about .sub-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 28px;
  margin-top: 26px;
}

@media (min-width: 900px) {
  .page-about .sub-grid {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr);
    gap: 44px;
    align-items: start;
  }
}

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

.page-about .sub-list li {
  position: relative;
  padding: 16px 0 16px 26px;
  border-bottom: 1px solid rgba(20, 98, 79, 0.15);
  font-size: 0.96rem;
  color: rgba(27, 43, 39, 0.78);
}

.page-about .sub-list li:first-child {
  border-top: 1px solid rgba(20, 98, 79, 0.15);
}

.page-about .sub-list li::before {
  content: "";
  position: absolute;
  left: 3px;
  top: 26px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--jade-600);
}

.page-about .sub-list strong {
  color: var(--text-light);
  font-weight: 700;
}

.page-about .sub-card {
  padding: 26px 24px 28px;
  border-radius: var(--radius-xl);
  background: linear-gradient(152deg, #0C1F1B 0%, #13302A 100%);
  border: 1px solid rgba(43, 227, 198, 0.22);
  color: var(--text-dark);
}

.page-about .sub-card__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(2.2rem, 7vw, 2.9rem);
  font-weight: 700;
  line-height: 1;
  color: var(--cyan-500);
}

.page-about .sub-card__label {
  margin: 12px 0 22px;
  font-size: 0.9rem;
  line-height: 1.7;
  color: rgba(234, 247, 243, 0.78);
}

/* ---------- 06 规模 ---------- */
.page-about .scale-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
}

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

@media (min-width: 1040px) {
  .page-about .scale-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 22px;
  }
}

.page-about .scale {
  padding: 22px 20px 24px;
  border-radius: var(--radius-l);
  border: 1px solid rgba(43, 227, 198, 0.16);
  background: rgba(6, 17, 15, 0.55);
}

.page-about .scale__num {
  font-family: var(--font-mono);
  font-size: clamp(2rem, 5.5vw, 2.75rem);
  font-weight: 700;
  line-height: 1;
  color: var(--cyan-500);
}

.page-about .scale__unit {
  margin-left: 5px;
  font-family: var(--font-mono);
  font-size: 0.92rem;
  color: var(--cyan-600);
}

.page-about .scale__label {
  margin: 12px 0 0;
  font-size: 0.86rem;
  line-height: 1.62;
  color: rgba(234, 247, 243, 0.72);
}

.page-about .scale-cta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 18px 26px;
  margin-top: 38px;
  padding-top: 28px;
  border-top: 1px solid rgba(43, 227, 198, 0.18);
}

.page-about .scale-cta p {
  margin: 0;
  max-width: 56ch;
  font-size: 0.94rem;
  color: rgba(234, 247, 243, 0.78);
}

/* ---------- 图片容器 ---------- */
.page-about .figure {
  margin: 0;
}

.page-about .figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-l);
  border: 1px solid rgba(43, 227, 198, 0.2);
  background: var(--ink-700);
  object-fit: cover;
}

.page-about .sec--light .figure img {
  border-color: rgba(20, 98, 79, 0.18);
  background: var(--paper-100);
}

.page-about .figure__caption {
  margin-top: 12px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  line-height: 1.65;
  color: var(--mist-400);
}

.page-about .sec--light .figure__caption {
  color: #5B726D;
}

.page-about .sec--light .figure {
  margin-top: 8px;
}

.page-about .figure--wide {
  margin-top: 4px;
}

/* ---------- 窄屏收口 ---------- */
@media (max-width: 480px) {
  .page-about .hero {
    padding-top: 22px;
    padding-bottom: 44px;
  }

  .page-about .hero__facts {
    gap: 14px 26px;
  }

  .page-about .sec__inner {
    padding-top: 44px;
    padding-bottom: 52px;
  }

  .page-about .ver {
    padding-left: 20px;
  }

  .page-about .sub-card,
  .page-about .cadence {
    padding-left: 18px;
    padding-right: 18px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .rail__link,
  .page-about .ver__box,
  .page-about .cadence {
    transition-duration: 0.01ms;
  }
}