.page-about {
  --about-paper-ink: rgba(14, 28, 40, .74);
  background: var(--ink-900);
  color: var(--paper-100);
  font-family: var(--font-body);
  padding-bottom: clamp(64px, 8vw, 120px);
}

.page-about ::selection {
  background: var(--signal-500);
  color: var(--ink-900);
}

.page-about a {
  color: var(--cyan-400);
}

.page-about .about-link {
  color: var(--cyan-400);
  text-decoration: none;
  border-bottom: 1px solid rgba(47, 217, 198, .45);
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

.page-about .about-link:hover {
  color: var(--cyan-200);
  border-bottom-color: var(--cyan-200);
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumb {
  padding-top: clamp(18px, 3vw, 32px);
}

.page-about .breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--muted);
}

.page-about .breadcrumb__list li + li::before {
  content: "/";
  margin-right: 6px;
  color: var(--hair);
}

.page-about .breadcrumb__link {
  color: var(--cyan-400);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color var(--dur) var(--ease);
}

.page-about .breadcrumb__link:hover {
  border-bottom-color: var(--cyan-400);
}

.page-about .breadcrumb__current {
  color: var(--muted);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  margin-top: clamp(26px, 4vw, 48px);
  padding-bottom: clamp(36px, 5vw, 64px);
  border-bottom: 1px dashed var(--hair);
}

.page-about .about-hero__eyebrow {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  margin: 0 0 clamp(20px, 3vw, 28px);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--cyan-200);
}

.page-about .page-title {
  margin: 0 0 clamp(20px, 3vw, 30px);
  max-width: 16em;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(29px, 4.4vw, 54px);
  line-height: 1.16;
  letter-spacing: -.02em;
  color: var(--paper-100);
}

.page-about .page-title__no {
  display: block;
  margin-bottom: 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .24em;
  color: var(--signal-500);
}

.page-about .about-hero__lead {
  margin: 0 0 clamp(24px, 3vw, 34px);
  max-width: 33em;
  font-size: clamp(16px, 1.5vw, 18px);
  line-height: 1.9;
  color: var(--muted);
}

.page-about .about-hero__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

/* ---------- 章节通用 ---------- */
.page-about .section {
  padding-block: clamp(44px, 6vw, 84px);
}

.page-about .section + .section {
  border-top: 1px solid var(--hair-soft);
}

.page-about .section-title {
  position: relative;
  margin: 0 0 clamp(18px, 3vw, 30px);
  padding-bottom: 14px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(21px, 2.6vw, 33px);
  line-height: 1.32;
  letter-spacing: -.01em;
  color: var(--paper-100);
}

.page-about .section-title::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 44px;
  height: 2px;
  background: var(--cyan-400);
}

.page-about .paper .section-title {
  color: var(--text-900);
}

.page-about .about-text {
  max-width: 34em;
  font-size: 16.5px;
  line-height: 1.9;
  color: var(--muted);
}

.page-about .about-text p {
  margin: 0;
}

.page-about .about-text p + p {
  margin-top: 1em;
}

/* ---------- 图像 ---------- */
.page-about .figure {
  margin: 0;
}

.page-about .figure__media {
  overflow: hidden;
  border: 1px solid var(--hair);
  background: var(--ink-700);
}

.page-about .figure__media img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .figure__caption {
  margin-top: 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.7;
  letter-spacing: .03em;
  color: var(--gray-500);
}

/* ---------- 每天在整理什么 ---------- */
.page-about .about-daily__grid {
  display: grid;
  gap: clamp(24px, 4vw, 44px);
}

.page-about .about-daily__figure {
  order: -1;
}

/* ---------- 时间轴 ---------- */
.page-about .about-stages__lead {
  margin: 0 0 clamp(24px, 3vw, 34px);
  max-width: 34em;
  font-size: 16px;
  line-height: 1.9;
  color: var(--muted);
}

.page-about .about-timeline {
  position: relative;
  margin: 0;
  padding: 0 0 0 clamp(26px, 4vw, 40px);
  list-style: none;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 16px;
  bottom: 26px;
  width: 1px;
  background-image: linear-gradient(to bottom, var(--signal-500) 0 8px, transparent 8px 16px);
  background-size: 1px 16px;
  background-repeat: repeat-y;
  opacity: .7;
}

.page-about .about-timeline__item {
  position: relative;
  padding-bottom: 4px;
}

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: calc(1px - clamp(26px, 4vw, 40px));
  top: 24px;
  width: 9px;
  height: 9px;
  border: 1.5px solid var(--signal-500);
  background: var(--ink-900);
}

.page-about .about-timeline__fold > .fold__summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
  padding: 12px 0;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(17px, 1.9vw, 21px);
  line-height: 1.45;
  color: var(--paper-100);
  transition: color var(--dur) var(--ease);
}

.page-about .about-timeline__fold > .fold__summary::-webkit-details-marker {
  display: none;
}

.page-about .about-timeline__fold > .fold__summary::marker {
  content: "";
}

.page-about .about-timeline__fold > .fold__summary::after {
  content: "+";
  margin-left: auto;
  padding-left: 12px;
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 600;
  color: var(--signal-500);
}

.page-about .about-timeline__fold[open] > .fold__summary::after {
  content: "−";
}

.page-about .about-timeline__fold > .fold__summary:hover {
  color: var(--cyan-200);
}

.page-about .about-timeline__stage {
  padding: 3px 9px;
  border: 1px solid rgba(255, 107, 44, .5);
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 600;
  letter-spacing: .12em;
  color: var(--signal-300);
}

.page-about .about-timeline__fold .fold__body {
  max-width: 36em;
  padding: 2px 0 18px;
  font-size: 15.5px;
  line-height: 1.9;
  color: var(--muted);
}

.page-about .about-timeline__fold .fold__body p {
  margin: 0;
}

/* ---------- 团队分工（纸层） ---------- */
.page-about .about-team__stack {
  position: relative;
  margin-bottom: 10px;
}

.page-about .about-team__stack::before,
.page-about .about-team__stack::after {
  content: "";
  position: absolute;
  inset: 0;
  border: 1px solid var(--paper-300);
  background: var(--paper-100);
  pointer-events: none;
}

.page-about .about-team__stack::before {
  transform: translate(-9px, 9px);
  opacity: .42;
}

.page-about .about-team__stack::after {
  transform: translate(-4px, 4px);
  opacity: .72;
}

.page-about .about-team__paper {
  position: relative;
  z-index: 1;
  padding: clamp(24px, 4vw, 48px);
  border: 1px solid var(--paper-300);
  background-color: var(--paper-100);
  background-image:
    radial-gradient(circle at 18% 22%, rgba(14, 28, 40, .045) 0 1px, transparent 1px),
    radial-gradient(circle at 72% 64%, rgba(14, 28, 40, .035) 0 1px, transparent 1px);
  background-size: 7px 7px, 11px 11px;
  color: var(--text-900);
}

.page-about .about-team__intro {
  margin: 0 0 clamp(22px, 3vw, 32px);
  max-width: 34em;
  font-size: 16px;
  line-height: 1.85;
  color: var(--about-paper-ink);
}

.page-about .about-team__list {
  display: grid;
  gap: 22px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-team__item {
  padding-left: 16px;
  border-left: 2px solid var(--paper-300);
}

.page-about .about-team__no {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 40px;
  margin-bottom: 12px;
  padding: 5px 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .08em;
  color: var(--paper-100);
  background: var(--ink-900);
  border-radius: 1px;
}

.page-about .about-team__role {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 17px;
  line-height: 1.4;
  color: var(--text-900);
}

.page-about .about-team__desc {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--about-paper-ink);
}

/* ---------- 三步核验 ---------- */
.page-about .about-verify__intro {
  margin: 0 0 clamp(20px, 3vw, 30px);
  max-width: 34em;
  font-size: 16px;
  line-height: 1.9;
  color: var(--muted);
}

.page-about .about-verify .tablist {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin: 0;
  padding: 0;
  border-bottom: 1px solid var(--hair);
}

.page-about .about-verify .tab {
  appearance: none;
  margin-bottom: -1px;
  padding: 11px 14px;
  cursor: pointer;
  font-family: var(--font-mono);
  font-size: 12.5px;
  font-weight: 600;
  letter-spacing: .03em;
  color: var(--muted);
  background: transparent;
  border: 1px solid var(--hair);
  border-bottom-color: transparent;
  border-radius: 2px 2px 0 0;
  transition: color var(--dur) var(--ease), background var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-verify .tab:hover {
  color: var(--paper-100);
  border-color: var(--signal-300);
}

.page-about .about-verify .tab[aria-selected="true"],
.page-about .about-verify .tab[data-active="true"] {
  color: var(--ink-900);
  background: var(--signal-500);
  border-color: var(--signal-500);
}

.page-about .about-verify .tab:focus-visible {
  outline: 2px solid var(--cyan-400);
  outline-offset: 3px;
}

.page-about .about-verify .tabpanel {
  padding: clamp(20px, 3vw, 32px);
  border: 1px solid var(--hair);
  border-top: none;
  background: var(--ink-700);
}

.page-about .about-verify .tabpanel[data-active="false"] {
  display: none;
}

.page-about .about-verify__stamp {
  display: inline-block;
  margin-bottom: 14px;
  padding: 4px 10px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 600;
  letter-spacing: .16em;
  color: var(--signal-500);
  border: 1.5px solid var(--signal-500);
  border-radius: 0;
}

.page-about .about-verify__lead {
  margin: 0 0 20px;
  max-width: 34em;
  font-size: 16px;
  line-height: 1.9;
  color: var(--paper-100);
}

.page-about .about-verify__io {
  display: grid;
  gap: 16px;
  margin: 0;
  padding-top: 18px;
  border-top: 1px dashed var(--hair);
}

.page-about .about-verify__io dt {
  margin-bottom: 6px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 600;
  letter-spacing: .14em;
  color: var(--cyan-400);
}

.page-about .about-verify__io dd {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--muted);
}

/* ---------- 覆盖范围 ---------- */
.page-about .about-coverage__lead {
  margin: 0 0 clamp(24px, 3vw, 34px);
  max-width: 36em;
  font-size: 16px;
  line-height: 1.9;
  color: var(--muted);
}

.page-about .about-coverage__stats {
  display: grid;
  gap: 1px;
  margin: 0 0 clamp(26px, 4vw, 40px);
  padding: 1px;
  list-style: none;
  background: var(--hair);
  border: 1px solid var(--hair);
}

.page-about .about-stat {
  padding: 20px 18px;
  background: var(--ink-900);
}

.page-about .about-stat__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(26px, 3.2vw, 34px);
  font-weight: 600;
  line-height: 1.1;
  letter-spacing: -.02em;
  color: var(--signal-500);
}

.page-about .about-stat__unit {
  margin-left: 4px;
  font-family: var(--font-body);
  font-size: 13px;
  font-weight: 400;
  letter-spacing: 0;
  color: var(--signal-300);
}

.page-about .about-stat__label {
  display: block;
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.65;
  color: var(--muted);
}

.page-about .about-coverage__text {
  max-width: 38em;
}

.page-about .about-coverage__figures {
  display: grid;
  gap: clamp(20px, 3vw, 30px);
  margin-top: clamp(26px, 4vw, 42px);
}

/* ---------- 为什么值得 ---------- */
.page-about .about-why__list {
  display: grid;
  gap: 16px;
  margin: 0 0 clamp(26px, 4vw, 38px);
  padding: 0;
  list-style: none;
}

.page-about .about-why__item {
  padding: 20px 18px;
  background: var(--ink-700);
  border: 1px solid var(--hair);
  border-top: 2px solid var(--cyan-400);
}

.page-about .about-why__title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 16.5px;
  line-height: 1.45;
  color: var(--cyan-200);
}

.page-about .about-why__desc {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--muted);
}

.page-about .about-why__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ---------- 右侧导览 ---------- */
.page-about .about-rail {
  position: sticky;
  top: calc(var(--header-h) + 28px);
  padding-left: 22px;
  border-left: 1px solid var(--hair);
}

.page-about .about-rail .index-rail__head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 14px;
  padding-bottom: 10px;
  border-bottom: 1px dashed var(--hair);
}

.page-about .about-rail .index-rail__title {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .16em;
  color: var(--cyan-200);
}

.page-about .about-rail .index-rail__count {
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: var(--gray-500);
}

.page-about .about-rail .index-rail__list {
  display: grid;
  gap: 2px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-rail .index-rail__link {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 8px 0;
  font-size: 14px;
  line-height: 1.55;
  color: var(--muted);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--dur) var(--ease);
}

.page-about .about-rail .index-rail__link:hover {
  color: var(--paper-100);
}

.page-about .about-rail .index-rail__link[aria-current="true"] {
  color: var(--cyan-400);
}

.page-about .about-rail .index-rail__no {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 600;
  letter-spacing: .06em;
  color: var(--signal-500);
}

.page-about .about-rail .index-rail__link:focus-visible {
  outline: 2px solid var(--cyan-400);
  outline-offset: 3px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 760px) {
  .page-about .about-daily__grid {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, .9fr);
    align-items: start;
  }

  .page-about .about-daily__figure {
    order: 0;
  }

  .page-about .about-team__list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 24px;
  }

  .page-about .about-verify__io {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: 20px;
  }

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

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

@media (min-width: 900px) {
  .page-about .about-coverage__figures {
    grid-template-columns: minmax(0, 1.25fr) minmax(0, 1fr);
    align-items: end;
  }
}

@media (min-width: 980px) {
  .page-about .about-coverage__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (max-width: 1179px) {
  .page-about .about-rail {
    position: static;
    margin-bottom: 8px;
    padding: 18px 0 0;
    border-left: none;
    border-top: 1px solid var(--hair);
  }

  .page-about .about-rail .index-rail__list {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
  }

  .page-about .about-rail .index-rail__list li {
    flex: 0 0 auto;
  }

  .page-about .about-rail .index-rail__link {
    padding: 6px 10px;
    font-size: 13px;
    border: 1px solid var(--hair);
  }
}

@media (max-width: 559px) {
  .page-about .about-verify .tablist {
    flex-direction: column;
    border-bottom: none;
  }

  .page-about .about-verify .tab {
    width: 100%;
    margin-bottom: 0;
    text-align: left;
    border-bottom: 1px solid var(--hair);
    border-radius: 0;
  }

  .page-about .about-verify .tabpanel {
    border-top: 1px solid var(--hair);
  }

  .page-about .about-why__actions .btn {
    flex: 1 1 100%;
    text-align: center;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about * {
    transition-duration: .01ms !important;
  }
}