.page-about {
  --about-rail-w: 88px;
  background: var(--ink-void);
  color: var(--paper-mist);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  letter-spacing: 0.01em;
  overflow-x: hidden;
}

.page-about img {
  max-width: 100%;
  height: auto;
}

/* ---------- 首屏框景 ---------- */

.page-about .about-hero {
  position: relative;
  padding-top: clamp(24px, 4.5vw, 52px);
  isolation: isolate;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: var(--gradient-veil);
  background-repeat: no-repeat;
  background-size: 100% clamp(220px, 42vh, 420px);
  opacity: 0.4;
  z-index: -1;
  pointer-events: none;
}

.page-about .about-hero .breadcrumb {
  margin-bottom: clamp(18px, 3vw, 34px);
}

.page-about .about-frame {
  position: relative;
  border: 1px solid var(--line-hair);
  border-radius: var(--radius);
  background: rgba(8, 28, 22, 0.62);
  overflow: hidden;
}

.page-about .about-frame__ticks {
  height: 14px;
  border-bottom: 1px solid var(--line-hair);
  background-image: repeating-linear-gradient(
    90deg,
    var(--line-hair) 0 1px,
    transparent 1px 32px
  );
  background-size: 32px 14px;
  background-repeat: repeat-x;
}

.page-about .about-frame__body {
  display: grid;
  gap: clamp(24px, 4vw, 44px);
  padding: clamp(24px, 4vw, 54px) clamp(18px, 3.4vw, 48px) clamp(26px, 4vw, 48px);
}

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

.page-about .about-frame__lead .index-tag {
  margin: 0 0 16px;
}

.page-about .about-title {
  margin: 0 0 20px;
  font-family: var(--font-display);
  font-size: clamp(32px, 5.6vw, 72px);
  font-weight: 300;
  line-height: 1.03;
  letter-spacing: -0.02em;
  color: var(--paper-mist);
}

.page-about .about-lede {
  margin: 0;
  max-width: 56ch;
  font-size: clamp(15px, 1.5vw, 17px);
  color: var(--mist-gray);
}

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

.page-about .about-stat {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 16px 16px 18px;
  background: var(--ink-void);
  min-width: 0;
}

.page-about .about-stat__value {
  font-family: var(--font-display);
  font-size: clamp(26px, 3.4vw, 42px);
  font-weight: 300;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--paper-mist);
  font-variant-numeric: tabular-nums;
}

.page-about .about-stat__unit {
  margin-left: 3px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 400;
  letter-spacing: 0.06em;
  color: var(--mist-gray);
}

.page-about .about-stat__label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  line-height: 1.5;
  color: var(--mist-gray);
}

/* ---------- 首屏横图 ---------- */

.page-about .about-banner {
  margin: 0;
  padding: clamp(28px, 4.5vw, 58px) 0;
}

.page-about .about-banner__caption {
  margin-top: 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.05em;
  line-height: 1.7;
  color: var(--mist-gray);
}

/* ---------- 章节骨架 ---------- */

.page-about .about-section {
  padding: clamp(40px, 6vw, 88px) 0;
  border-top: 1px solid var(--line-hair);
}

.page-about .about-section--deep {
  background-image: linear-gradient(
    180deg,
    rgba(14, 51, 39, 0.62) 0%,
    rgba(14, 51, 39, 0) 100%
  );
}

.page-about .about-section__inner {
  display: grid;
  gap: 18px;
}

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

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

.page-about .about-rail__num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--grass-core);
}

.page-about .about-rail__line {
  flex: 1 1 auto;
  min-width: 24px;
  height: 1px;
  background: var(--line-hair);
}

.page-about .about-rail__kicker {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--mist-gray);
  white-space: nowrap;
}

.page-about .about-section__title {
  margin: 0 0 14px;
  font-family: var(--font-display);
  font-size: clamp(24px, 3.2vw, 38px);
  font-weight: 300;
  line-height: 1.18;
  letter-spacing: -0.015em;
  color: var(--paper-mist);
}

.page-about .about-section__lead {
  margin: 0;
  max-width: 64ch;
  font-size: 16px;
  color: var(--mist-gray);
}

.page-about .about-rule {
  display: block;
  max-width: 340px;
  height: 1px;
  margin: 22px 0 24px;
  background-image: repeating-linear-gradient(
    90deg,
    var(--line-hair) 0 1px,
    transparent 1px 24px
  );
  background-size: 24px 1px;
  background-repeat: repeat-x;
}

/* ---------- 团队分工 ---------- */

.page-about .about-roles {
  list-style: none;
  margin: 0;
  padding: 0;
  border-bottom: 1px solid var(--line-hair);
}

.page-about .about-role {
  display: grid;
  grid-template-columns: 30px minmax(0, 1fr);
  column-gap: 14px;
  padding: 20px 0;
  border-top: 1px solid var(--line-hair);
}

.page-about .about-role__idx {
  grid-column: 1;
  grid-row: 1;
  padding-top: 4px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--grass-soft);
}

.page-about .about-role__name {
  grid-column: 2;
  grid-row: 1;
  margin: 0;
  font-size: 17px;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--paper-mist);
}

.page-about .about-role__desc {
  grid-column: 2;
  grid-row: 2;
  margin: 8px 0 0;
  font-size: 15px;
  line-height: 1.72;
  color: var(--mist-gray);
}

.page-about .about-role__out {
  grid-column: 2;
  grid-row: 3;
  margin: 10px 0 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.05em;
  line-height: 1.6;
  color: var(--grass-soft);
}

/* ---------- 校验流程 ---------- */

.page-about .about-flow-layout {
  display: grid;
  gap: 28px;
}

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

.page-about .about-flow__step {
  position: relative;
  padding: 0 0 16px 34px;
}

.page-about .about-flow__step::before {
  content: "";
  position: absolute;
  left: 8px;
  top: 16px;
  bottom: 0;
  width: 1px;
  background: var(--line-hair);
}

.page-about .about-flow__step::after {
  content: "";
  position: absolute;
  left: 4px;
  top: 9px;
  width: 9px;
  height: 9px;
  border: 1px solid var(--grass-core);
  border-radius: 50%;
  background: var(--ink-void);
}

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

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

.page-about .about-flow__details {
  border-radius: var(--radius);
  transition: background-color 0.18s var(--ease);
}

.page-about .about-flow__details[open] {
  background: var(--ink-slab);
  box-shadow: inset 0 0 0 1px var(--line-hair);
}

.page-about .about-flow__summary {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 10px 14px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-flow__summary:focus-visible {
  outline: 1px solid var(--grass-core);
  outline-offset: 2px;
}

.page-about .about-flow__idx {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--mist-gray);
}

.page-about .about-flow__name {
  font-size: 16px;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--paper-mist);
}

.page-about .about-flow__details[open] .about-flow__name {
  color: var(--grass-soft);
}

.page-about .about-flow__summary::after {
  content: "＋";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--mist-gray);
}

.page-about .about-flow__details[open] .about-flow__summary::after {
  content: "－";
  color: var(--grass-core);
}

.page-about .about-flow__panel {
  padding: 0 14px 16px;
}

.page-about .about-flow__panel p {
  margin: 0 0 12px;
  font-size: 15px;
  line-height: 1.75;
  color: var(--mist-gray);
}

.page-about .about-flow__fields {
  display: grid;
  gap: 8px;
  margin: 0;
}

.page-about .about-flow__field {
  display: flex;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  line-height: 1.6;
  color: var(--grass-soft);
}

.page-about .about-flow__field dt {
  flex: 0 0 auto;
  color: var(--mist-gray);
}

.page-about .about-flow__field dd {
  margin: 0;
}

.page-about .about-flow__media {
  margin: 0;
}

.page-about .about-flow__media .media-frame {
  border: 1px solid var(--line-hair);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .about-flow__media img {
  display: block;
  width: 100%;
  height: auto;
  max-height: 460px;
  object-fit: cover;
}

.page-about .about-flow__media figcaption {
  margin-top: 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.05em;
  line-height: 1.7;
  color: var(--mist-gray);
}

/* ---------- 来源与口径 ---------- */

.page-about .about-sources {
  list-style: none;
  margin: 0;
  padding: 0;
  border-bottom: 1px solid var(--line-hair);
}

.page-about .about-source {
  display: grid;
  gap: 8px;
  padding: 20px 0;
  border-top: 1px solid var(--line-hair);
}

.page-about .about-source__tag {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--grass-core);
}

.page-about .about-source__tag::before {
  content: "";
  width: 20px;
  height: 1px;
  background: var(--grass-core);
}

.page-about .about-source__desc {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--mist-gray);
}

.page-about .about-note {
  margin-top: 26px;
  padding: 18px 20px 18px 22px;
  border-left: 2px solid var(--signal-orange);
  background: var(--ink-slab);
  border-radius: 0 var(--radius) var(--radius) 0;
}

.page-about .about-note p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--paper-mist);
}

.page-about .about-source-figure {
  margin: 32px 0 0;
}

.page-about .about-source-figure .media-frame {
  border: 1px solid var(--line-hair);
  border-radius: var(--radius);
  overflow: hidden;
}

/* ---------- 更新节奏与版本 ---------- */

.page-about .about-cadence {
  list-style: none;
  margin: 0 0 36px;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line-hair);
  border: 1px solid var(--line-hair);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .about-cadence__item {
  background: var(--ink-slab);
  padding: 18px 18px 20px;
  min-width: 0;
}

.page-about .about-cadence__key {
  display: block;
  margin-bottom: 8px;
  font-size: 15px;
  font-weight: 600;
  color: var(--paper-mist);
}

.page-about .about-cadence__val {
  display: block;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.05em;
  color: var(--grass-soft);
  font-variant-numeric: tabular-nums;
}

.page-about .about-timeline {
  list-style: none;
  margin: 0 0 28px;
  padding: 0 0 0 22px;
  border-left: 1px solid var(--line-hair);
}

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

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

.page-about .about-timeline__item:focus-visible {
  outline: 1px solid var(--grass-core);
  outline-offset: 4px;
}

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: -27px;
  top: 10px;
  width: 9px;
  height: 9px;
  border: 1px solid var(--grass-core);
  border-radius: 50%;
  background: var(--ink-void);
}

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

.page-about .about-timeline__ver {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--grass-core);
}

.page-about .about-timeline__name {
  font-size: 16px;
  font-weight: 600;
  color: var(--paper-mist);
}

.page-about .about-timeline__note {
  margin: 8px 0 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--mist-gray);
}

/* ---------- 纠错与协作 ---------- */

.page-about .about-fix {
  display: grid;
  gap: 28px;
}

.page-about .about-fix__steps {
  list-style: none;
  margin: 0;
  padding: 0;
  counter-reset: fixstep;
}

.page-about .about-fix__step {
  position: relative;
  counter-increment: fixstep;
  padding: 0 0 20px 32px;
}

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

.page-about .about-fix__step::before {
  content: counter(fixstep, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 3px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--grass-core);
}

.page-about .about-fix__step p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--mist-gray);
}

.page-about .about-fix__step strong {
  color: var(--paper-mist);
  font-weight: 600;
}

.page-about .about-contact {
  border: 1px solid var(--line-hair);
  border-radius: var(--radius);
  background: var(--ink-slab);
  padding: 22px 20px 24px;
}

.page-about .about-contact__title {
  margin: 0 0 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line-hair);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--mist-gray);
}

.page-about .about-contact__mail {
  display: block;
  margin-bottom: 12px;
  font-family: var(--font-mono);
  font-size: 14px;
  letter-spacing: 0.02em;
  line-height: 1.6;
  color: var(--grass-soft);
  word-break: break-all;
}

.page-about .about-contact__note {
  margin: 0 0 12px;
  font-size: 14px;
  line-height: 1.72;
  color: var(--mist-gray);
}

.page-about .about-contact__subject {
  margin: 0;
  padding-top: 12px;
  border-top: 1px solid var(--line-hair);
  font-size: 14px;
  line-height: 1.72;
  color: var(--grass-soft);
}

.page-about .about-links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

/* ---------- 内联链接 ---------- */

.page-about .about-inline-link {
  color: var(--grass-soft);
  text-decoration: none;
  border-bottom: 1px solid var(--line-hair);
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.page-about .about-inline-link:hover,
.page-about .about-inline-link:focus-visible {
  color: var(--grass-core);
  border-bottom-color: var(--grass-core);
}

/* ---------- 响应式 ---------- */

@media (min-width: 620px) {
  .page-about .about-flow__fields {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 8px 24px;
  }
}

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

@media (min-width: 900px) {
  .page-about .about-frame__body {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: end;
  }

  .page-about .about-section__inner {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    column-gap: 48px;
  }

  .page-about .about-rail {
    flex-direction: column;
    align-items: flex-start;
    gap: 14px;
    padding-top: 8px;
  }

  .page-about .about-rail__line {
    flex: 0 0 auto;
    width: 1px;
    min-width: 0;
    height: 64px;
  }

  .page-about .about-role {
    grid-template-columns: 44px 180px minmax(0, 1fr);
    column-gap: 24px;
    row-gap: 6px;
    align-items: start;
  }

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

  .page-about .about-role__name {
    grid-column: 2;
    grid-row: 1;
    padding-top: 2px;
  }

  .page-about .about-role__desc {
    grid-column: 3;
    grid-row: 1;
    margin-top: 0;
  }

  .page-about .about-role__out {
    grid-column: 3;
    grid-row: 2;
    margin-top: 0;
  }

  .page-about .about-flow-layout {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 44px;
    align-items: start;
  }

  .page-about .about-source {
    grid-template-columns: 200px minmax(0, 1fr);
    column-gap: 28px;
    align-items: baseline;
  }

  .page-about .about-fix {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 44px;
    align-items: start;
  }
}

@media (min-width: 900px) and (hover: hover) {
  .page-about .about-timeline__note {
    max-height: 0;
    margin-top: 0;
    opacity: 0;
    overflow: hidden;
    transition: max-height 0.22s var(--ease), opacity 0.22s var(--ease),
      margin-top 0.22s var(--ease);
  }

  .page-about .about-timeline__item:hover .about-timeline__note,
  .page-about .about-timeline__item:focus-within .about-timeline__note,
  .page-about .about-timeline__item:focus .about-timeline__note {
    max-height: 140px;
    margin-top: 8px;
    opacity: 1;
  }
}

@media (max-width: 600px) {
  .page-about .about-frame__body {
    padding-left: 16px;
    padding-right: 16px;
  }

  .page-about .about-title {
    font-size: clamp(28px, 8.4vw, 40px);
  }

  .page-about .about-rail__kicker {
    letter-spacing: 0.08em;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition-duration: 0.001ms !important;
    animation-duration: 0.001ms !important;
  }
}