.page-about {
  --about-offset: 60px;
  overflow-x: hidden;
}

.page-about .about-hero {
  position: relative;
  isolation: isolate;
}

.page-about .about-hero > .container {
  position: relative;
  z-index: 2;
}

.page-about .about-hero__glow {
  position: absolute;
  top: -24%;
  right: -18%;
  width: 62vw;
  height: 62vw;
  max-width: 820px;
  max-height: 820px;
  z-index: 0;
  pointer-events: none;
  background: radial-gradient(circle at 34% 34%, rgba(138, 107, 255, 0.4), transparent 62%);
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(2rem, 6vw, 4rem);
  margin-top: clamp(1.5rem, 4vw, 3rem);
  align-items: end;
}

.page-about .about-hero__lead h1 {
  margin: 0.6rem 0 1.1rem;
  font-family: var(--font-head);
  font-size: clamp(2.4rem, 8.4vw, 5.4rem);
  font-weight: 800;
  line-height: 1.02;
  letter-spacing: -0.02em;
}

.page-about .about-hero__intro {
  max-width: 46ch;
  margin: 0 0 1.9rem;
  font-size: 1.0625rem;
  line-height: 1.75;
  color: var(--mist);
}

.page-about .about-hero__cta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem;
}

.page-about .about-hero__panel {
  border: 2px solid rgba(53, 230, 210, 0.42);
  background: linear-gradient(158deg, rgba(22, 38, 79, 0.92), rgba(6, 11, 26, 0.94));
  box-shadow: var(--shadow-hard);
  padding: clamp(1.25rem, 3vw, 1.9rem);
}

.page-about .about-hero__panel-title {
  margin: 0 0 1rem;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--cyan);
}

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

.page-about .about-facts__row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.7rem 0;
  border-bottom: 1px solid rgba(74, 90, 128, 0.4);
}

.page-about .about-facts__row:last-child {
  border-bottom: 0;
}

.page-about .about-facts__row dt {
  font-size: 0.9375rem;
  color: var(--mist);
}

.page-about .about-facts__row dd {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 1.375rem;
  font-weight: 800;
  font-variant-numeric: tabular-nums;
  color: var(--amber);
}

/* ---------- 通用区块头 ---------- */

.page-about .about-head {
  max-width: 62ch;
  margin-bottom: clamp(2rem, 5vw, 3.4rem);
}

.page-about .about-head h2 {
  margin: 0.55rem 0 0.9rem;
  font-family: var(--font-head);
  font-size: clamp(1.65rem, 5vw, 2.85rem);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.015em;
}

.page-about .about-head__lead {
  margin: 0;
  max-width: 58ch;
  font-size: 1.0625rem;
  line-height: 1.75;
  color: var(--mist);
}

/* ---------- 时间轴 ---------- */

.page-about .about-timeline {
  position: relative;
  background: linear-gradient(180deg, rgba(11, 22, 51, 0.4), rgba(6, 11, 26, 0.86));
}

.page-about .about-timeline__figure {
  margin: 0 0 clamp(2.5rem, 6vw, 4rem);
}

.page-about .timeline {
  position: relative;
  margin: 0;
  padding: 0 0 0 40px;
  list-style: none;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 12px;
  top: 0.7rem;
  bottom: 0.7rem;
  width: 2px;
  background: linear-gradient(180deg, var(--cyan) 0%, rgba(53, 230, 210, 0.45) 52%, rgba(74, 90, 128, 0.22) 100%);
}

.page-about .timeline__item {
  position: relative;
  padding-bottom: clamp(2.4rem, 6vw, 4.6rem);
}

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

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: -34px;
  top: 0.55rem;
  width: 14px;
  height: 14px;
  background: var(--cyan);
  transform: rotate(45deg);
  box-shadow: 0 0 0 4px rgba(6, 11, 26, 0.95);
}

.page-about .timeline__item:nth-child(2n)::before {
  background: var(--violet);
}

.page-about .timeline__year {
  margin: 0 0 0.3rem;
  font-family: var(--font-mono);
  font-size: clamp(1.9rem, 8vw, 3.6rem);
  font-weight: 800;
  line-height: 1;
  letter-spacing: -0.03em;
  font-variant-numeric: tabular-nums;
  color: var(--cyan);
}

.page-about .timeline__item:nth-child(2n) .timeline__year {
  color: var(--violet);
}

.page-about .timeline__title {
  margin: 0 0 0.6rem;
  font-family: var(--font-head);
  font-size: 1.3rem;
  font-weight: 700;
  line-height: 1.35;
}

.page-about .timeline__body p {
  margin: 0 0 0.75rem;
  max-width: 62ch;
  font-size: 1.0625rem;
  line-height: 1.75;
  color: var(--mist);
}

.page-about .timeline__meta {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  letter-spacing: 0.02em;
  color: rgba(74, 90, 128, 0.95);
  border-top: 1px solid rgba(74, 90, 128, 0.36);
  padding-top: 0.6rem;
}

/* ---------- 两条推进线 ---------- */

.page-about .about-lines {
  position: relative;
  background: linear-gradient(180deg, rgba(22, 38, 79, 0.58), rgba(6, 11, 26, 0.92));
  border-top: 1px solid rgba(53, 230, 210, 0.26);
}

.page-about .line-track {
  display: grid;
  gap: 1.25rem;
}

.page-about .line-card {
  border: 2px solid rgba(74, 90, 128, 0.5);
  background: rgba(6, 11, 26, 0.62);
  padding: clamp(1.25rem, 3.4vw, 2rem);
  transition: border-color var(--dur) var(--ease), transform var(--dur) var(--ease),
    box-shadow var(--dur) var(--ease);
}

.page-about .line-card:hover,
.page-about .line-card:focus-within {
  border-color: var(--amber);
  transform: translate(-2px, -2px);
  box-shadow: var(--shadow-hard-amber);
}

.page-about .line-card__tag {
  display: inline-block;
  margin: 0 0 0.9rem;
  padding: 0.25rem 0.6rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  color: var(--ink-900);
  background: var(--cyan);
}

.page-about .line-card--ops .line-card__tag {
  background: var(--amber);
}

.page-about .line-card h3 {
  margin: 0 0 1rem;
  font-family: var(--font-head);
  font-size: 1.2rem;
  font-weight: 700;
  line-height: 1.4;
}

.page-about .line-list {
  margin: 0 0 1.2rem;
  padding: 0;
  list-style: none;
}

.page-about .line-list li {
  position: relative;
  padding-left: 1.15rem;
  margin-bottom: 0.6rem;
  font-size: 1rem;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .line-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.68em;
  width: 7px;
  height: 2px;
  background: var(--cyan);
}

.page-about .line-card--ops .line-list li::before {
  background: var(--amber);
}

.page-about .line-card__out {
  margin: 0;
  padding-top: 0.85rem;
  border-top: 1px solid rgba(74, 90, 128, 0.42);
  font-size: 0.9375rem;
  line-height: 1.65;
  color: rgba(201, 214, 240, 0.82);
}

.page-about .line-join {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.7rem;
  padding: 0.4rem 0;
}

.page-about .line-join__dot {
  width: 14px;
  height: 14px;
  flex: none;
  background: var(--violet);
  transform: rotate(45deg);
  box-shadow: 0 0 20px rgba(138, 107, 255, 0.7);
}

.page-about .line-join__label {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.16em;
  color: var(--violet);
}

.page-about .about-lines__figure {
  margin: clamp(2.5rem, 6vw, 4rem) 0 0;
}

/* ---------- 暖纸白区块 ---------- */

.page-about .about-paper {
  background: var(--paper);
  color: var(--paper-ink);
}

.page-about .about-head--paper h2 {
  color: var(--paper-ink);
}

.page-about .about-head--paper .about-head__lead {
  color: rgba(16, 20, 24, 0.78);
}

.page-about .eyebrow--paper {
  color: #0F1D42;
}

.page-about .check-grid {
  display: grid;
  gap: clamp(2rem, 5vw, 3.5rem);
}

.page-about .check-rules h3,
.page-about .check-list h3 {
  margin: 0 0 0.8rem;
  font-family: var(--font-head);
  font-size: 1.2rem;
  font-weight: 800;
  color: var(--paper-ink);
}

.page-about .check-rules p,
.page-about .check-list__hint {
  margin: 0 0 1rem;
  max-width: 46ch;
  font-size: 1rem;
  line-height: 1.75;
  color: rgba(16, 20, 24, 0.8);
}

.page-about .rule-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  margin: 1.1rem 0 1.2rem;
  padding: 0;
  list-style: none;
}

.page-about .rule-tags li {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.04em;
  padding: 0.3rem 0.55rem;
  border: 1px solid rgba(16, 20, 24, 0.32);
  background: rgba(11, 22, 51, 0.06);
  color: var(--ink-800);
}

.page-about .check-rules__note {
  padding-top: 0.9rem;
  border-top: 1px solid rgba(16, 20, 24, 0.2);
  font-size: 0.9375rem;
  line-height: 1.7;
  color: rgba(16, 20, 24, 0.72);
}

.page-about .check-item {
  border-bottom: 1px solid rgba(16, 20, 24, 0.22);
}

.page-about .check-item__head {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  padding: 0.9rem 0;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-head);
  font-size: 1.0625rem;
  font-weight: 700;
  color: var(--paper-ink);
}

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

.page-about .check-item__head::marker {
  content: "";
}

.page-about .check-item__idx {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-variant-numeric: tabular-nums;
  color: rgba(16, 20, 24, 0.5);
}

.page-about .check-item__name {
  flex: 1 1 auto;
}

.page-about .check-item__sign {
  position: relative;
  flex: none;
  width: 16px;
  height: 16px;
}

.page-about .check-item__sign::before,
.page-about .check-item__sign::after {
  content: "";
  position: absolute;
  inset: 0;
  margin: auto;
  background: var(--paper-ink);
  transition: transform var(--dur) var(--ease);
}

.page-about .check-item__sign::before {
  width: 16px;
  height: 2px;
}

.page-about .check-item__sign::after {
  width: 2px;
  height: 16px;
}

.page-about .check-item[open] .check-item__sign::after {
  transform: scaleY(0);
}

.page-about .check-item__body {
  padding: 0 0 1.1rem;
}

.page-about .check-item__body p {
  margin: 0;
  max-width: 60ch;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: rgba(16, 20, 24, 0.78);
}

/* ---------- 团队与伙伴 ---------- */

.page-about .about-team {
  background: linear-gradient(180deg, rgba(15, 29, 66, 0.9), rgba(6, 11, 26, 0.96));
}

.page-about .about-team__grid {
  display: grid;
  gap: clamp(2rem, 5vw, 3.5rem);
}

.page-about .about-team__lead h2 {
  margin: 0.55rem 0 0.9rem;
  font-family: var(--font-head);
  font-size: clamp(1.65rem, 5vw, 2.85rem);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.015em;
}

.page-about .about-team__intro {
  margin: 0 0 1.6rem;
  max-width: 56ch;
  font-size: 1.0625rem;
  line-height: 1.75;
  color: var(--mist);
}

.page-about .team-groups {
  margin: 0 0 1.5rem;
  padding: 0;
  list-style: none;
  border-top: 1px solid rgba(74, 90, 128, 0.42);
}

.page-about .team-groups__item {
  display: grid;
  gap: 0.3rem;
  padding: 0.95rem 0;
  border-bottom: 1px solid rgba(74, 90, 128, 0.42);
}

.page-about .team-groups__name {
  font-family: var(--font-head);
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--cyan);
}

.page-about .team-groups__desc {
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .about-team__note {
  margin: 0 0 1.6rem;
  padding: 0.9rem 1.1rem;
  border-left: 4px solid var(--amber);
  background: rgba(255, 179, 71, 0.08);
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .about-partners {
  padding-top: 0.4rem;
}

.page-about .about-partners__title {
  margin: 0 0 0.7rem;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  letter-spacing: 0.1em;
  color: var(--mist);
}

.page-about .partner-kinds {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .partner-kinds li {
  padding: 0.35rem 0.75rem;
  border: 1px solid rgba(138, 107, 255, 0.6);
  font-size: 0.9375rem;
  color: var(--mist);
}

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

.page-about .about-team__figure .img-frame__tag {
  display: block;
  margin-top: 0.7rem;
}

/* ---------- 更新节奏 ---------- */

.page-about .about-cadence {
  position: relative;
  background: linear-gradient(180deg, rgba(11, 22, 51, 0.9), rgba(6, 11, 26, 0.98));
  border-top: 1px solid rgba(53, 230, 210, 0.22);
}

.page-about .cadence {
  display: grid;
  gap: 1.5rem;
  margin: 0 0 1.6rem;
  padding: 0;
  list-style: none;
}

.page-about .cadence__item {
  position: relative;
  padding-top: 1.4rem;
}

.page-about .cadence__bar {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, var(--cyan), rgba(53, 230, 210, 0.12));
}

.page-about .cadence__item::before {
  content: "";
  position: absolute;
  top: -4px;
  left: 0;
  width: 10px;
  height: 10px;
  background: var(--cyan);
  transform: rotate(45deg);
}

.page-about .cadence__value {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: clamp(2rem, 7vw, 3.2rem);
  font-weight: 800;
  line-height: 1;
  font-variant-numeric: tabular-nums;
  color: var(--amber);
}

.page-about .cadence__unit {
  margin-left: 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  letter-spacing: 0.08em;
  color: var(--mist);
}

.page-about .cadence__label {
  display: block;
  margin-top: 0.5rem;
  font-size: 1rem;
  color: var(--mist);
}

.page-about .about-cadence__note {
  margin: 0 0 2.2rem;
  max-width: 62ch;
  font-size: 1rem;
  line-height: 1.75;
  color: var(--mist);
}

.page-about .about-cadence__cta {
  padding: clamp(1.4rem, 4vw, 2.2rem);
  border: 2px solid rgba(53, 230, 210, 0.4);
  background: linear-gradient(150deg, rgba(22, 38, 79, 0.86), rgba(6, 11, 26, 0.9));
  box-shadow: var(--shadow-hard);
}

.page-about .about-cadence__cta p {
  margin: 0 0 1.1rem;
  font-family: var(--font-head);
  font-size: clamp(1.05rem, 2.6vw, 1.4rem);
  font-weight: 700;
  line-height: 1.45;
  max-width: 42ch;
}

.page-about .about-cadence__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem;
}

/* ---------- 媒体查询 ---------- */

@media (min-width: 700px) {
  .page-about .cadence {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 2rem;
  }
}

@media (min-width: 960px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    column-gap: clamp(2.5rem, 5vw, 4.5rem);
  }

  .page-about .timeline__item {
    display: grid;
    grid-template-columns: 170px minmax(0, 1fr);
    column-gap: 2.5rem;
    align-items: start;
  }

  .page-about .timeline__year {
    font-size: clamp(2.4rem, 3.6vw, 3.4rem);
    text-align: right;
    margin-bottom: 0;
  }

  .page-about .timeline__item:nth-child(2n) .timeline__body {
    padding-left: var(--about-offset);
  }

  .page-about .line-track {
    grid-template-columns: minmax(0, 1fr) 96px minmax(0, 1fr);
    align-items: stretch;
    gap: 0;
  }

  .page-about .line-join {
    flex-direction: column;
    padding: 0;
  }

  .page-about .line-join::before {
    content: "";
    flex: 1 1 auto;
    width: 2px;
    min-height: 24px;
    background: linear-gradient(180deg, rgba(138, 107, 255, 0.15), rgba(138, 107, 255, 0.75), rgba(138, 107, 255, 0.15));
  }

  .page-about .check-grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    column-gap: clamp(2.5rem, 5vw, 4rem);
  }

  .page-about .about-team__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    column-gap: clamp(2.5rem, 5vw, 4rem);
    align-items: start;
  }
}

@media (min-width: 1200px) {
  .page-about .timeline {
    padding-left: 52px;
  }

  .page-about .timeline::before {
    left: 16px;
  }

  .page-about .timeline__item::before {
    left: -44px;
    top: 0.7rem;
    width: 16px;
    height: 16px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .line-card,
  .page-about .check-item__sign::before,
  .page-about .check-item__sign::after {
    transition: color var(--dur) var(--ease), background-color var(--dur) var(--ease);
  }

  .page-about .line-card:hover,
  .page-about .line-card:focus-within {
    transform: none;
  }
}