.page-about {
  position: relative;
  overflow-x: hidden;
  color: var(--c-mist);
  font-family: var(--f-body);
  line-height: 1.75;
}

.page-about::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: min(720px, 88vh);
  background:
    radial-gradient(58% 55% at 10% 0%, rgba(184, 242, 74, 0.1), transparent 70%),
    radial-gradient(52% 48% at 92% 4%, rgba(255, 122, 77, 0.09), transparent 72%);
  pointer-events: none;
}

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

/* ---------- 首屏 ---------- */
.page-about .about-intro {
  padding: clamp(24px, 4vw, 48px) 0 clamp(36px, 5vw, 64px);
  border-bottom: 1px solid var(--c-grid);
}

.page-about .breadcrumb ul {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0 0 clamp(20px, 3vw, 32px);
  padding: 0;
  list-style: none;
  font-size: var(--t-xs);
  letter-spacing: 0.14em;
  color: var(--c-cool);
}

.page-about .breadcrumb a {
  color: var(--c-cool);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible {
  color: var(--c-lime);
  border-bottom-color: var(--c-lime-deep);
}

.page-about .breadcrumb li:not(:last-child)::after {
  content: "/";
  margin-left: 8px;
  color: var(--c-haze);
}

.page-about .about-intro__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 3.5vw, 40px);
}

.page-about .about-intro__main,
.page-about .about-intro__side {
  min-width: 0;
}

.page-about .about-intro h1 {
  margin: 14px 0 0;
  font-family: var(--f-display);
  font-weight: 800;
  font-size: clamp(32px, 7vw, 64px);
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--c-mist);
  max-width: 16ch;
}

.page-about .about-lead {
  margin: 20px 0 0;
  max-width: 40em;
  font-size: clamp(16px, 1.6vw, 18px);
  line-height: 1.8;
  color: var(--c-cool);
}

.page-about .about-intro__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(24px, 3vw, 34px);
}

.page-about .about-facts {
  margin: 0;
  padding: 4px 18px;
  border: 1px solid var(--c-grid);
  background: linear-gradient(155deg, var(--c-tactic), rgba(11, 32, 48, 0.35));
}

.page-about .about-fact {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 14px;
  padding: 13px 0;
  border-bottom: 1px dashed var(--c-grid);
}

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

.page-about .about-fact__k {
  font-size: var(--t-xs);
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--c-cool);
}

.page-about .about-fact__v {
  font-family: var(--f-mono);
  font-weight: 600;
  font-size: var(--t-md);
  letter-spacing: 0.02em;
  font-variant-numeric: tabular-nums;
  color: var(--c-lime);
  white-space: nowrap;
}

.page-about .about-fact__u {
  margin-left: 4px;
  font-family: var(--f-body);
  font-size: var(--t-xs);
  font-weight: 400;
  color: var(--c-cool);
}

/* ---------- 通用区块 ---------- */
.page-about .about-section {
  padding: clamp(40px, 6vw, 80px) 0;
  border-bottom: 1px solid var(--c-grid);
}

.page-about .about-section__head {
  max-width: 62ch;
  margin-bottom: clamp(24px, 3.5vw, 44px);
}

.page-about .about-h2 {
  margin: 12px 0 0;
  font-family: var(--f-display);
  font-weight: 800;
  font-size: clamp(26px, 4.2vw, 44px);
  line-height: 1.14;
  letter-spacing: -0.02em;
  color: var(--c-mist);
}

.page-about .about-sub {
  margin: 14px 0 0;
  max-width: 42em;
  font-size: var(--t-base);
  line-height: 1.8;
  color: var(--c-cool);
}

/* ---------- 研究板 ---------- */
.page-about .about-board {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 3vw, 36px);
}

.page-about .about-board > div {
  min-width: 0;
}

.page-about .about-board__summary {
  margin: 0;
  padding-left: 18px;
  border-left: 2px solid var(--c-lime);
  font-family: var(--f-display);
  font-weight: 700;
  font-size: clamp(20px, 2.6vw, 30px);
  line-height: 1.42;
  letter-spacing: -0.01em;
  color: var(--c-mist);
}

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

.page-about .about-board__list li {
  position: relative;
  padding: 16px 0 16px 22px;
  border-top: 1px solid var(--c-grid);
  font-size: var(--t-base);
  line-height: 1.8;
  color: var(--c-cool);
}

.page-about .about-board__list li:last-child {
  border-bottom: 1px solid var(--c-grid);
}

.page-about .about-board__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 27px;
  width: 12px;
  height: 1px;
  background: var(--c-lime-deep);
}

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

.page-about .about-board__link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  margin-top: 18px;
  font-size: var(--t-sm);
  letter-spacing: 0.08em;
  color: var(--c-coral);
  text-decoration: none;
  border-bottom: 1px solid rgba(255, 122, 77, 0.4);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-board__link::after {
  content: "→";
}

.page-about .about-board__link:hover,
.page-about .about-board__link:focus-visible {
  color: var(--c-coral-soft);
  border-bottom-color: var(--c-coral-soft);
}

/* ---------- 生产流程 ---------- */
.page-about .about-process__fig {
  margin: 0 0 clamp(24px, 3vw, 36px);
  border: 1px solid var(--c-grid);
}

.page-about .about-process__steps {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  border: 1px solid var(--c-grid);
  background: var(--c-grid);
}

.page-about .about-step {
  background: var(--c-tactic);
  padding: 20px 18px 22px;
}

.page-about .about-step__num {
  margin: 0;
  font-family: var(--f-mono);
  font-size: var(--t-xs);
  letter-spacing: 0.16em;
  color: var(--c-lime);
}

.page-about .about-step__title {
  margin: 10px 0 0;
  font-size: var(--t-base);
  font-weight: 600;
  color: var(--c-mist);
}

.page-about .about-step__text {
  margin: 8px 0 0;
  font-size: var(--t-sm);
  line-height: 1.75;
  color: var(--c-cool);
}

/* ---------- 时间轴 ---------- */
.page-about .about-tl {
  position: relative;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-tl::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 12px;
  bottom: 12px;
  width: 1px;
  background: var(--c-grid);
}

.page-about .about-tl__item {
  position: relative;
  padding: 0 0 clamp(24px, 3vw, 34px) 34px;
}

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

.page-about .about-tl__item::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 9px;
  width: 11px;
  height: 11px;
  background: var(--c-ink);
  border: 1px solid var(--c-lime-deep);
  transition: background var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.page-about .about-tl__item:hover::before {
  background: var(--c-lime);
  box-shadow: 0 0 0 3px rgba(184, 242, 74, 0.16);
}

.page-about .about-tl__year {
  display: inline-block;
  font-family: var(--f-mono);
  font-weight: 600;
  font-size: var(--t-md);
  letter-spacing: 0.02em;
  font-variant-numeric: tabular-nums;
  color: var(--c-lime);
}

.page-about .about-tl__title {
  margin: 6px 0 0;
  font-size: var(--t-base);
  font-weight: 600;
  color: var(--c-mist);
}

.page-about .about-tl__text {
  margin: 6px 0 0;
  max-width: 54ch;
  font-size: var(--t-sm);
  line-height: 1.8;
  color: var(--c-cool);
}

/* ---------- 水下长曝光带 ---------- */
.page-about .about-band {
  position: relative;
  overflow: hidden;
  border-top: 1px solid var(--c-grid);
  border-bottom: 1px solid var(--c-grid);
  background: linear-gradient(100deg, #04101a, var(--c-tactic) 55%, var(--c-ink));
}

.page-about .about-band img {
  display: block;
  width: 100%;
  height: clamp(150px, 22vw, 280px);
  object-fit: cover;
  opacity: 0.62;
}

.page-about .about-band::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, rgba(6, 20, 32, 0.95), rgba(6, 20, 32, 0.16) 44%, rgba(6, 20, 32, 0.88));
  pointer-events: none;
}

.page-about .about-band__caption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 2;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 10px 16px;
  padding: 12px clamp(16px, 4vw, 40px);
  border-top: 1px solid rgba(22, 50, 63, 0.8);
  background: linear-gradient(180deg, rgba(6, 20, 32, 0), rgba(6, 20, 32, 0.7));
  font-family: var(--f-mono);
  font-size: var(--t-xs);
  letter-spacing: 0.16em;
  color: var(--c-cool);
}

/* ---------- 乐鱼专区 ---------- */
.page-about .about-zone__body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 3vw, 40px);
}

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

.page-about .about-zone__points {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 14px;
}

.page-about .about-zone__points li {
  padding-left: 18px;
  border-left: 1px solid var(--c-grid);
  font-size: var(--t-sm);
  line-height: 1.8;
  color: var(--c-cool);
}

.page-about .about-zone__points strong {
  display: block;
  margin-bottom: 2px;
  font-size: var(--t-base);
  font-weight: 600;
  color: var(--c-mist);
}

.page-about .filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 16px;
}

.page-about .filter-btn {
  min-height: 44px;
  padding: 0 16px;
  font-family: var(--f-body);
  font-size: var(--t-sm);
  color: var(--c-cool);
  background: transparent;
  border: 1px solid var(--c-grid);
  cursor: pointer;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .filter-btn:hover {
  color: var(--c-mist);
  border-color: var(--c-stone);
}

.page-about .filter-btn[aria-pressed="true"] {
  color: var(--c-ink);
  background: var(--c-lime);
  border-color: var(--c-lime);
}

.page-about .about-club-list {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
}

.page-about .about-club-card {
  padding: 16px;
  background: var(--c-clay);
  border: 1px solid var(--c-grid);
  border-left: 2px solid var(--c-clay-line);
  transition: border-color var(--dur) var(--ease);
}

.page-about .about-club-card:hover {
  border-left-color: var(--c-lime);
}

.page-about .about-club-card__name {
  display: block;
  font-family: var(--f-display);
  font-weight: 700;
  font-size: var(--t-md);
  letter-spacing: -0.01em;
  color: var(--c-sand);
}

.page-about .about-club-card__league {
  display: block;
  margin-top: 4px;
  font-size: var(--t-xs);
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--c-cool);
}

.page-about .about-club-card__stat {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  padding: 10px 0;
}

.page-about .about-club-card__stat:first-of-type {
  margin-top: 12px;
  border-top: 1px dashed var(--c-clay-line);
}

.page-about .about-club-card__stat + .about-club-card__stat {
  border-top: 1px dashed var(--c-clay-line);
}

.page-about .about-club-card__k {
  font-size: var(--t-xs);
  color: var(--c-cool);
}

.page-about .about-club-card__v {
  font-family: var(--f-mono);
  font-weight: 600;
  font-size: var(--t-sm);
  letter-spacing: 0.02em;
  font-variant-numeric: tabular-nums;
  color: var(--c-lime);
}

.page-about .filter-item[data-enter] {
  animation: about-fade-in 200ms var(--ease);
}

.page-about .filter-empty {
  margin: 0;
  padding: 18px;
  border: 1px dashed var(--c-grid);
  font-size: var(--t-sm);
  color: var(--c-haze);
}

@keyframes about-fade-in {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

/* ---------- 团队 ---------- */
.page-about .about-team__fig {
  margin: 0 0 clamp(20px, 3vw, 32px);
  border: 1px solid var(--c-grid);
}

.page-about .about-team__cards {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
}

.page-about .about-team__card {
  background: var(--c-tactic);
  border: 1px solid var(--c-grid);
}

.page-about .about-team__summary {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  min-height: 44px;
  padding: 18px;
  list-style: none;
  cursor: pointer;
}

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

.page-about .about-team__summary:focus-visible {
  outline: 2px solid var(--c-lime-deep);
  outline-offset: -2px;
}

.page-about .about-team__idx {
  flex: 0 0 auto;
  padding-top: 3px;
  font-family: var(--f-mono);
  font-size: var(--t-xs);
  letter-spacing: 0.1em;
  color: var(--c-lime);
}

.page-about .about-team__name {
  flex: 1;
  min-width: 0;
  font-family: var(--f-display);
  font-weight: 700;
  font-size: var(--t-md);
  line-height: 1.3;
  color: var(--c-mist);
}

.page-about .about-team__toggle {
  position: relative;
  flex: 0 0 auto;
  width: 14px;
  height: 14px;
  margin-top: 6px;
}

.page-about .about-team__toggle::before,
.page-about .about-team__toggle::after {
  content: "";
  position: absolute;
  background: var(--c-lime);
  transition: transform var(--dur) var(--ease);
}

.page-about .about-team__toggle::before {
  left: 0;
  top: 6px;
  width: 14px;
  height: 1px;
}

.page-about .about-team__toggle::after {
  left: 6px;
  top: 0;
  width: 1px;
  height: 14px;
}

.page-about .about-team__card[open] .about-team__toggle::after {
  transform: scaleY(0);
}

.page-about .about-team__card[open] {
  border-color: var(--c-stone);
}

.page-about .about-team__body {
  padding: 16px 18px 20px;
  border-top: 1px solid var(--c-grid);
}

.page-about .about-team__body p {
  margin: 0;
  font-size: var(--t-sm);
  line-height: 1.8;
  color: var(--c-cool);
}

.page-about .about-team__body p + p {
  margin-top: 10px;
}

/* ---------- 对外协作 ---------- */
.page-about .about-collab {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  border: 1px solid var(--c-grid);
  background: var(--c-grid);
}

.page-about .about-collab__item {
  padding: clamp(20px, 3vw, 28px);
  background: var(--c-tactic);
  border-top: 2px solid var(--c-lime-deep);
}

.page-about .about-collab__title {
  margin: 0;
  font-family: var(--f-display);
  font-weight: 700;
  font-size: var(--t-md);
  letter-spacing: -0.01em;
  color: var(--c-mist);
}

.page-about .about-collab__text {
  margin: 10px 0 0;
  font-size: var(--t-sm);
  line-height: 1.8;
  color: var(--c-cool);
}

.page-about .about-collab__foot {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-top: clamp(20px, 3vw, 30px);
  padding-top: 20px;
  border-top: 1px solid var(--c-grid);
}

.page-about .about-collab__foot p {
  margin: 0;
  font-size: var(--t-sm);
  color: var(--c-cool);
}

/* ---------- 结尾 ---------- */
.page-about .about-closing {
  padding-bottom: clamp(44px, 6vw, 80px);
}

.page-about .about-cta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 22px;
  padding: clamp(24px, 4vw, 44px);
  border: 1px solid var(--c-grid);
  background: linear-gradient(120deg, rgba(184, 242, 74, 0.09), rgba(11, 32, 48, 0.92) 52%, rgba(255, 122, 77, 0.09));
}

.page-about .about-cta__text {
  min-width: 0;
  max-width: 46ch;
}

.page-about .about-cta .about-intro__actions {
  margin-top: 0;
}

/* ---------- 断点 ---------- */
@media (min-width: 760px) {
  .page-about .about-process__steps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

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

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

  .page-about .about-zone__body {
    grid-template-columns: minmax(0, 4fr) minmax(0, 8fr);
    align-items: start;
  }

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

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

@media (min-width: 1080px) {
  .page-about .about-process__steps {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    animation: none !important;
    transition: none !important;
  }
}