.page-about {
  --about-rule: rgba(201, 162, 39, 0.22);
  --about-soft: rgba(213, 216, 221, 0.12);
  --about-line-red: rgba(200, 16, 46, 0.4);
  background: var(--ink-900);
  color: var(--gray-200);
}

/* ---------------- 页头 ---------------- */
.page-about .about-dossier {
  position: relative;
  padding-top: clamp(34px, 6vw, 78px);
  padding-bottom: clamp(38px, 6vw, 76px);
  border-bottom: 1px solid var(--about-rule);
}

.page-about .about-dossier::after {
  content: "";
  position: absolute;
  right: 0;
  bottom: -1px;
  width: min(38%, 420px);
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--red-600));
}

.page-about .about-dossier__kicker {
  margin: 20px 0 14px;
  font-size: 0.72rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--gold-500);
}

.page-about .about-dossier__title {
  margin: 0 0 24px;
  max-width: 15em;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(1.9rem, 5.2vw, 3.4rem);
  line-height: 1.14;
  letter-spacing: -0.02em;
  color: #fff;
}

.page-about .about-dossier__lede {
  margin: 0;
  max-width: 60ch;
  padding-left: 20px;
  border-left: 2px solid var(--red-600);
  font-size: clamp(1.02rem, 1.7vw, 1.22rem);
  line-height: 1.92;
  color: var(--gray-200);
}

.page-about .about-dossier__lede::first-letter {
  font-family: var(--font-head);
  font-size: 1.7em;
  font-weight: 900;
  line-height: 1;
  color: var(--red-600);
  margin-right: 2px;
}

.page-about .about-dossier__facts {
  list-style: none;
  margin: clamp(28px, 4vw, 44px) 0 0;
  padding: clamp(20px, 3vw, 28px) 0 0;
  border-top: 1px solid var(--about-soft);
  display: flex;
  flex-wrap: wrap;
  gap: 16px 0;
}

.page-about .about-dossier__facts li {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding-right: clamp(18px, 3vw, 34px);
  margin-right: clamp(18px, 3vw, 34px);
  border-right: 1px solid var(--about-soft);
  font-size: 0.88rem;
  color: var(--gray-400);
}

.page-about .about-dossier__facts li:last-child {
  padding-right: 0;
  margin-right: 0;
  border-right: none;
}

.page-about .about-dossier__facts .num {
  font-family: var(--font-head);
  font-weight: 900;
  font-size: 1.55rem;
  line-height: 1;
  color: var(--red-600);
  font-variant-numeric: tabular-nums;
}

/* ---------------- 双翼骨架 ---------------- */
.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 36px;
  padding-top: clamp(40px, 6vw, 76px);
  padding-bottom: clamp(60px, 9vw, 120px);
}

.page-about .about-toc {
  border-bottom: 1px solid var(--about-soft);
  padding-bottom: 18px;
}

.page-about .about-toc__title {
  margin: 0 0 12px;
  font-size: 0.7rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--gold-500);
}

.page-about .about-toc__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: 4px;
  overflow-x: auto;
  scrollbar-width: none;
}

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

.page-about .about-toc__link {
  display: block;
  padding: 8px 14px;
  border-left: 2px solid transparent;
  border-radius: 0 6px 6px 0;
  font-size: 0.86rem;
  color: var(--gray-400);
  text-decoration: none;
  white-space: nowrap;
  transition: color var(--dur) var(--ease), background var(--dur) var(--ease),
    border-color var(--dur) var(--ease);
}

.page-about .about-toc__link:hover,
.page-about .about-toc__link:focus-visible {
  color: #fff;
  background: var(--glass-light);
}

.page-about .about-toc__link[aria-current="true"] {
  color: #fff;
  background: var(--glass-light);
  border-left-color: var(--red-600);
}

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

/* ---------------- 章节 ---------------- */
.page-about .about-chapter {
  padding-bottom: clamp(56px, 8vw, 118px);
  scroll-margin-top: calc(var(--header-h) + 26px);
}

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

.page-about .about-chapter__head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  align-items: baseline;
  gap: 12px 16px;
  padding-bottom: 16px;
  margin-bottom: clamp(24px, 3.4vw, 38px);
  border-bottom: 1px solid var(--about-rule);
}

.page-about .about-chapter__num {
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(1.4rem, 3vw, 2rem);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--gold-500);
  font-variant-numeric: tabular-nums;
}

.page-about .about-chapter__title {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(1.2rem, 2.6vw, 1.8rem);
  line-height: 1.32;
  letter-spacing: -0.01em;
  color: #fff;
}

/* ---------------- 结论 + 补充 ---------------- */
.page-about .about-claim {
  margin: 0 0 clamp(28px, 4vw, 42px);
}

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

.page-about .about-claim--spaced {
  margin-top: clamp(30px, 4vw, 48px);
}

.page-about .about-claim__lead {
  margin: 0 0 16px;
  padding-left: 16px;
  border-left: 3px solid var(--red-600);
  font-family: var(--font-head);
  font-weight: 700;
  font-size: clamp(1.04rem, 1.8vw, 1.2rem);
  line-height: 1.65;
  color: #fff;
}

.page-about .about-claim__lead--solo {
  margin-bottom: clamp(26px, 3.6vw, 40px);
}

.page-about .about-claim__list {
  list-style: none;
  margin: 0;
  padding: 0 0 0 19px;
}

.page-about .about-claim__list li {
  position: relative;
  padding: 7px 0 7px 20px;
  font-size: 0.97rem;
  line-height: 1.9;
  color: var(--gray-200);
}

.page-about .about-claim__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 1.12em;
  width: 6px;
  height: 6px;
  background: var(--gold-500);
  transform: rotate(45deg);
}

.page-about .about-claim__list strong {
  color: #fff;
  font-weight: 700;
}

/* ---------------- 团队 ---------------- */
.page-about .about-team-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 30px;
}

.page-about .about-team {
  margin: 0;
  display: grid;
  gap: 6px;
}

.page-about .about-team__row {
  padding: 22px 22px 22px 24px;
  background: var(--ink-800);
  border-left: 3px solid var(--steel-600);
  border-radius: 0 var(--radius) var(--radius) 0;
}

.page-about .about-team__row--ops {
  border-left-color: var(--red-600);
}

.page-about .about-team__row--edit {
  border-left-color: var(--gold-500);
}

.page-about .about-team__row--support {
  border-left-color: var(--steel-600);
}

.page-about .about-team__term {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: 1.06rem;
  color: #fff;
}

.page-about .about-team__size {
  font-size: 0.76rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--gold-500);
  font-variant-numeric: tabular-nums;
}

.page-about .about-team__desc {
  margin: 10px 0 0;
  font-size: 0.94rem;
  line-height: 1.88;
  color: var(--gray-200);
}

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

.page-about .about-figure .figure__frame {
  overflow: hidden;
  border-radius: var(--radius);
  border: 1px solid var(--about-soft);
  background: var(--ink-800);
}

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

.page-about .about-figure .figure__caption {
  margin-top: 12px;
  font-size: 0.82rem;
  line-height: 1.7;
  color: var(--gray-400);
}

.page-about .about-figure--path {
  margin-top: clamp(32px, 5vw, 56px);
}

/* ---------------- 版本时间轴 ---------------- */
.page-about .about-version {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 26px;
}

.page-about .about-version__stop {
  position: relative;
  padding-top: 30px;
}

.page-about .about-version__stop::before {
  content: "";
  position: absolute;
  top: 8px;
  left: 0;
  right: 0;
  height: 1px;
  background: var(--about-soft);
}

.page-about .about-version__dot {
  position: absolute;
  top: 5px;
  left: 0;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--steel-600);
}

.page-about .about-version__stop--v1 .about-version__dot {
  background: var(--steel-600);
}

.page-about .about-version__stop--v2 .about-version__dot {
  background: var(--gold-500);
}

.page-about .about-version__stop--v3 .about-version__dot {
  background: var(--red-600);
  box-shadow: 0 0 0 4px rgba(200, 16, 46, 0.16);
}

.page-about .about-version__tag {
  display: inline-block;
  margin: 0 0 12px;
  padding: 3px 12px;
  border: 1px solid var(--about-line-red);
  border-radius: 999px;
  font-family: var(--font-head);
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.14em;
  color: var(--red-600);
}

.page-about .about-version__name {
  margin: 0 0 10px;
  font-family: var(--font-head);
  font-size: 1.1rem;
  font-weight: 800;
  line-height: 1.4;
  color: #fff;
}

.page-about .about-version__text {
  margin: 0;
  font-size: 0.93rem;
  line-height: 1.88;
  color: var(--gray-400);
}

/* ---------------- 审校 ---------------- */
.page-about .about-audit-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 30px;
}

.page-about .about-audit {
  display: grid;
  gap: 14px;
}

.page-about .about-audit__gate {
  position: relative;
  padding: 24px 24px 24px 26px;
  background: var(--ink-800);
  border: 1px solid var(--about-soft);
  border-radius: var(--radius);
}

.page-about .about-audit__gate::before {
  content: "";
  position: absolute;
  left: -1px;
  top: 24px;
  bottom: 24px;
  width: 3px;
  background: var(--red-600);
  border-radius: 3px;
}

.page-about .about-audit__gate + .about-audit__gate::before {
  background: var(--gold-500);
}

.page-about .about-audit__step {
  margin: 0 0 10px;
  font-size: 0.72rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--gold-500);
}

.page-about .about-audit__title {
  margin: 0 0 10px;
  font-family: var(--font-head);
  font-size: 1.08rem;
  font-weight: 800;
  line-height: 1.42;
  color: #fff;
}

.page-about .about-audit__text {
  margin: 0;
  font-size: 0.94rem;
  line-height: 1.88;
  color: var(--gray-200);
}

.page-about .about-cadence {
  list-style: none;
  margin: clamp(30px, 4vw, 46px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--about-soft);
  border: 1px solid var(--about-soft);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .about-cadence__item {
  padding: 22px 20px;
  background: var(--ink-800);
}

.page-about .about-cadence__value {
  font-family: var(--font-head);
  font-size: 1.9rem;
  font-weight: 900;
  line-height: 1;
  color: var(--red-600);
  font-variant-numeric: tabular-nums;
}

.page-about .about-cadence__unit {
  margin-left: 6px;
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  color: var(--gold-500);
}

.page-about .about-cadence__label {
  margin: 12px 0 0;
  font-size: 0.87rem;
  line-height: 1.7;
  color: var(--gray-400);
}

/* ---------------- 用户 ---------------- */
.page-about .about-audience {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-audience__item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 16px;
  padding: 26px 0;
  border-top: 1px solid var(--about-soft);
}

.page-about .about-audience__item:last-child {
  border-bottom: 1px solid var(--about-soft);
}

.page-about .about-audience__num {
  padding-top: 5px;
  font-family: var(--font-head);
  font-size: 0.82rem;
  font-weight: 800;
  letter-spacing: 0.1em;
  color: var(--red-600);
  font-variant-numeric: tabular-nums;
}

.page-about .about-audience__body h3 {
  margin: 0 0 10px;
  font-family: var(--font-head);
  font-size: 1.06rem;
  font-weight: 800;
  line-height: 1.45;
  color: #fff;
}

.page-about .about-audience__body p {
  margin: 0;
  font-size: 0.95rem;
  line-height: 1.9;
  color: var(--gray-200);
}

.page-about .about-audience__foot {
  margin: clamp(26px, 3.6vw, 38px) 0 0;
  padding-left: 16px;
  border-left: 2px solid var(--gold-500);
  font-size: 0.94rem;
  line-height: 1.9;
  color: var(--gray-400);
}

.page-about .about-audience a,
.page-about .about-audience__foot a {
  color: var(--gray-200);
  text-decoration: none;
  border-bottom: 1px solid var(--about-line-red);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-audience a:hover,
.page-about .about-audience a:focus-visible,
.page-about .about-audience__foot a:hover,
.page-about .about-audience__foot a:focus-visible {
  color: var(--red-400);
  border-bottom-color: var(--red-400);
}

/* ---------------- 收束 ---------------- */
.page-about .about-next {
  position: relative;
  border-top: 1px solid var(--about-rule);
  background: linear-gradient(180deg, var(--ink-800), var(--ink-900));
  overflow: hidden;
}

.page-about .about-next::before {
  content: "";
  position: absolute;
  top: -120px;
  right: -60px;
  width: 420px;
  height: 420px;
  background: radial-gradient(circle, rgba(200, 16, 46, 0.16), transparent 68%);
  pointer-events: none;
}

.page-about .about-next__inner {
  position: relative;
  padding-top: clamp(48px, 7vw, 92px);
  padding-bottom: clamp(48px, 7vw, 92px);
}

.page-about .about-next__eyebrow {
  margin: 0 0 14px;
  font-size: 0.72rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--gold-500);
}

.page-about .about-next__title {
  margin: 0 0 18px;
  max-width: 22em;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(1.4rem, 3.2vw, 2.1rem);
  line-height: 1.3;
  letter-spacing: -0.015em;
  color: #fff;
}

.page-about .about-next__text {
  margin: 0 0 28px;
  max-width: 56ch;
  font-size: 0.98rem;
  line-height: 1.9;
  color: var(--gray-200);
}

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

/* ---------------- 响应式 ---------------- */
@media (min-width: 700px) {
  .page-about .about-cadence {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 820px) {
  .page-about .about-version {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0;
    position: relative;
  }

  .page-about .about-version__stop {
    padding: 34px 32px 0 0;
  }

  .page-about .about-version__stop::before {
    top: 12px;
    left: 0;
    right: 0;
    background: linear-gradient(90deg, var(--steel-600), var(--gold-500), var(--red-600));
    opacity: 0.5;
    height: 1px;
  }

  .page-about .about-version__dot {
    top: 9px;
  }

  .page-about .about-version__stop:last-child {
    padding-right: 0;
  }
}

@media (min-width: 900px) {
  .page-about .about-team-grid {
    grid-template-columns: minmax(0, 1.12fr) minmax(0, 0.88fr);
    gap: 38px;
    align-items: start;
  }

  .page-about .about-audit-grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.74fr);
    gap: 42px;
    align-items: start;
  }
}

@media (min-width: 960px) {
  .page-about .about-body {
    grid-template-columns: minmax(180px, 220px) minmax(0, 1fr);
    gap: clamp(40px, 5vw, 84px);
    align-items: start;
  }

  .page-about .about-toc {
    position: sticky;
    top: calc(var(--header-h) + 28px);
    align-self: start;
    border-bottom: none;
    padding-bottom: 0;
  }

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

  .page-about .about-toc__link {
    white-space: normal;
    line-height: 1.5;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-toc__link,
  .page-about .about-audience a,
  .page-about .about-audience__foot a {
    transition: none;
  }

  .page-about .about-next::before {
    display: none;
  }
}