/* ===== 品牌总览 · page-about ===== */
.page-about {
  --about-strand: 1px solid var(--structure);
  --about-chapter-gap: clamp(84px, 11vw, 148px);
  --about-nebula:
    radial-gradient(120% 78% at 10% 0%, rgba(122, 92, 255, .22), transparent 62%),
    radial-gradient(80% 62% at 92% 100%, rgba(77, 240, 224, .10), transparent 58%);
  background-color: var(--void);
  color: var(--text-primary);
}

/* ---------- 页首宣言 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  margin-top: calc(var(--header-h) * -1);
  padding: calc(var(--header-h) + clamp(36px, 6vw, 80px)) 0 clamp(52px, 8vw, 104px);
  background-color: var(--void);
  background-image: var(--about-nebula);
  background-repeat: no-repeat;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: .55;
  background-image: radial-gradient(rgba(242, 245, 255, .05) 1px, transparent 1px);
  background-size: 3px 3px;
}

.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
  display: grid;
  gap: clamp(30px, 5vw, 56px);
}

.page-about .about-hero__title {
  margin: clamp(18px, 2.6vw, 30px) 0 0;
  font-family: var(--font-display);
  font-weight: 300;
  font-size: clamp(2.4rem, 6.4vw, 5.2rem);
  line-height: 1.05;
  letter-spacing: .01em;
  color: var(--pure-white);
  text-wrap: balance;
}

.page-about .about-hero__title .em {
  font-family: var(--font-emphasis);
  font-weight: 900;
  color: var(--pure-white);
}

.page-about .about-hero__lede {
  margin: clamp(20px, 3vw, 34px) 0 0;
  max-width: 32em;
  font-size: clamp(1rem, 1.35vw, 1.12rem);
  line-height: 1.95;
  color: var(--text-secondary);
}

.page-about .about-hero__index {
  list-style: none;
  width: 100%;
  margin: clamp(26px, 4vw, 44px) 0 0;
  padding: var(--space-3) 0 0;
  border-top: var(--about-strand);
  display: flex;
  flex-wrap: wrap;
  gap: 10px clamp(20px, 3vw, 40px);
}

.page-about .about-hero__index li {
  font-size: 14px;
  letter-spacing: .06em;
  color: var(--text-secondary);
  white-space: nowrap;
}

.page-about .about-hero__figure {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 11;
}

.page-about .about-hero__figure img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* ---------- 主体骨架 ---------- */
.page-about .about-body {
  display: grid;
  gap: clamp(26px, 4vw, 44px);
  padding-top: clamp(48px, 7vw, 90px);
  padding-bottom: clamp(72px, 9vw, 128px);
}

/* ---------- 章节索引 ---------- */
.page-about .about-rail {
  position: sticky;
  top: calc(var(--header-h-compact) - 1px);
  z-index: 4;
  margin: 0 calc(var(--shell-pad) * -1);
  padding: var(--space-2) var(--shell-pad);
  background-color: rgba(5, 7, 15, .93);
  border-bottom: var(--about-strand);
  backdrop-filter: blur(12px);
}

.page-about .about-rail .index-label {
  display: none;
}

.page-about .about-rail__list {
  list-style: none;
  display: flex;
  gap: 10px;
  margin: 0;
  padding: 0 0 2px;
  overflow-x: auto;
  scrollbar-width: none;
}

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

.page-about .about-rail__link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  white-space: nowrap;
  padding: 9px 15px;
  border: var(--about-strand);
  border-radius: var(--radius-pill);
  font-size: 13px;
  letter-spacing: .05em;
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 140ms var(--ease-out), border-color 140ms var(--ease-out);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  color: var(--signal-cyan);
  border-color: var(--cyan-deep);
}

.page-about .about-rail__num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0;
  color: var(--signal-cyan);
  opacity: .85;
}

/* ---------- 章节通用 ---------- */
.page-about .chapter {
  margin-top: var(--about-chapter-gap);
  padding-top: clamp(28px, 4vw, 48px);
  border-top: var(--about-strand);
  scroll-margin-top: calc(var(--header-h-compact) + 68px);
}

.page-about .about-main > .chapter:first-of-type {
  margin-top: 0;
  padding-top: 0;
  border-top: 0;
}

.page-about .chapter__head {
  margin-bottom: clamp(20px, 3vw, 32px);
}

.page-about .chapter__head .index-label {
  color: var(--signal-cyan);
  font-family: var(--font-mono);
  letter-spacing: .18em;
}

.page-about .chapter__head .section-title {
  margin: 12px 0 0;
}

.page-about .chapter > .lead {
  max-width: 34em;
  margin: 0 0 clamp(26px, 3.6vw, 42px);
  font-size: clamp(1rem, 1.3vw, 1.1rem);
  line-height: 1.95;
  color: var(--text-secondary);
}

.page-about .chapter--end {
  border-top: 0;
}

/* ---------- 时间线 ---------- */
.page-about .timeline {
  list-style: none;
  margin: 0;
  padding: 0 0 0 clamp(18px, 3vw, 40px);
  border-left: 1px solid var(--structure);
}

.page-about .timeline__item {
  position: relative;
}

.page-about .timeline__item + .timeline__item {
  margin-top: clamp(26px, 3.4vw, 44px);
}

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  top: 16px;
  left: calc(-1 * clamp(18px, 3vw, 40px) - 3.5px);
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background-color: var(--signal-cyan);
  box-shadow: 0 0 0 4px rgba(77, 240, 224, .12);
}

.page-about .timeline__summary {
  position: relative;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px 22px;
  padding-right: 34px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .timeline__summary::after {
  content: "＋";
  position: absolute;
  right: 0;
  top: .3em;
  font-size: 1rem;
  line-height: 1;
  color: var(--index-blue);
  font-size: 16px;
  transition: color 180ms var(--ease-out);
}

.page-about .timeline__entry[open] .timeline__summary::after {
  content: "－";
  color: var(--signal-cyan);
}

.page-about .timeline__season {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(2.3rem, 5.8vw, 3.9rem);
  font-weight: 300;
  line-height: .95;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

.page-about .timeline__caption {
  font-size: clamp(1rem, 1.5vw, 1.2rem);
  color: var(--text-primary);
}

.page-about .timeline__text {
  max-width: 34em;
  margin: var(--space-2) 0 0;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--text-secondary);
}

/* ---------- 团队分组 ---------- */
.page-about .segmented {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  padding: 6px;
  border: var(--about-strand);
  border-radius: var(--radius-pill);
  background-color: var(--deep-field);
  width: fit-content;
  max-width: 100%;
}

.page-about .segmented [role="tab"] {
  appearance: none;
  border: 0;
  background: transparent;
  padding: 10px 20px;
  border-radius: var(--radius-pill);
  font-family: var(--font-body);
  font-size: 14px;
  letter-spacing: .05em;
  color: var(--text-secondary);
  cursor: pointer;
  transition: background-color 180ms var(--ease-out), color 180ms var(--ease-out);
}

.page-about .segmented [role="tab"][aria-selected="true"] {
  background-color: var(--signal-cyan);
  color: var(--ink-on-signal);
  font-weight: 600;
}

.page-about .segmented [role="tab"]:focus-visible {
  outline: 2px solid var(--signal-cyan);
  outline-offset: 2px;
}

.page-about .about-panels {
  margin-top: var(--space-3);
}

.page-about .about-panel {
  padding: clamp(22px, 3vw, 36px);
  border-radius: var(--radius-lg);
  border: 1px solid var(--structure);
  background-color: var(--panel);
}

.page-about .about-panel + .about-panel {
  margin-top: var(--space-3);
}

.page-about .about-panel__title {
  margin: 0 0 14px;
  font-family: var(--font-emphasis);
  font-weight: 900;
  font-size: clamp(1.1rem, 1.8vw, 1.35rem);
  line-height: 1.4;
  color: var(--pure-white);
}

.page-about .about-panel p {
  max-width: 34em;
  margin: 0;
  font-size: 1rem;
  line-height: 1.9;
  color: var(--text-secondary);
}

.page-about .about-points {
  list-style: none;
  margin: clamp(18px, 2.4vw, 26px) 0 0;
  padding: clamp(16px, 2.2vw, 22px) 0 0;
  border-top: var(--about-strand);
  display: grid;
  gap: 10px;
}

.page-about .about-points li {
  position: relative;
  padding-left: 20px;
  font-size: .95rem;
  line-height: 1.7;
  color: var(--text-secondary);
}

.page-about .about-points li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .62em;
  width: 8px;
  height: 1px;
  background-color: var(--signal-cyan);
}

.page-about .about-team__figure {
  margin: clamp(32px, 4.4vw, 56px) 0 0;
  aspect-ratio: 3 / 2;
}

.page-about .about-team__figure img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* ---------- 球迷组织 ---------- */
.page-about .about-split {
  display: grid;
  gap: clamp(24px, 3.6vw, 40px);
}

.page-about .about-facts {
  margin: 0;
  border-top: var(--about-strand);
}

.page-about .about-facts__row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 18px;
  padding: 16px 0;
  border-bottom: var(--about-strand);
}

.page-about .about-facts dt {
  font-size: 14px;
  letter-spacing: .08em;
  color: var(--text-secondary);
}

.page-about .about-facts dd {
  margin: 0;
  font-size: clamp(1.1rem, 1.7vw, 1.4rem);
  color: var(--text-primary);
}

.page-about .about-facts dd .data-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  color: var(--signal-cyan);
}

.page-about .about-yaxing__figure {
  margin: 0;
  aspect-ratio: 3 / 2;
}

.page-about .about-yaxing__figure img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* ---------- 口径与版本 ---------- */
.page-about .about-version {
  display: grid;
  gap: var(--space-3);
}

.page-about .about-version__card {
  padding: clamp(22px, 3vw, 34px);
  border: 1px solid var(--structure);
  border-radius: var(--radius-lg);
  background-color: var(--panel);
}

.page-about .about-version__card .index-label {
  color: var(--index-blue);
  font-family: var(--font-mono);
  letter-spacing: .18em;
}

.page-about .about-version__code {
  margin: 10px 0 14px;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(2.4rem, 4.8vw, 3.4rem);
  font-weight: 500;
  line-height: 1;
  color: var(--signal-cyan);
}

.page-about .about-version__note {
  max-width: 30em;
  margin: 0;
  font-size: .98rem;
  line-height: 1.9;
  color: var(--text-secondary);
}

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

.page-about .about-version__list li {
  display: flex;
  gap: 12px;
  align-items: baseline;
  font-size: .96rem;
  line-height: 1.75;
  color: var(--text-secondary);
}

.page-about .about-version__list .data-num {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 1.05rem;
  color: var(--text-primary);
}

.page-about .about-flag {
  display: flex;
  align-items: baseline;
  gap: 10px;
  max-width: 34em;
  margin: clamp(24px, 3vw, 34px) 0 0;
  padding: 16px 18px;
  border-radius: var(--radius-md);
  border: 1px solid rgba(255, 107, 44, .38);
  background-color: rgba(255, 107, 44, .07);
  font-size: .94rem;
  line-height: 1.75;
  color: var(--text-secondary);
}

.page-about .about-flag .status-dot {
  flex: 0 0 auto;
}

/* ---------- 合作与引用 ---------- */
.page-about .about-partners {
  display: grid;
  gap: var(--space-3);
  margin-bottom: clamp(24px, 3.2vw, 36px);
}

.page-about .about-partner {
  padding: clamp(22px, 3vw, 34px);
  border: 1px solid var(--structure);
  border-radius: var(--radius-lg);
  background-image: linear-gradient(150deg, rgba(30, 44, 85, .6), rgba(10, 18, 38, .92));
}

.page-about .about-partner__count {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(2.3rem, 4.4vw, 3.2rem);
  font-weight: 500;
  line-height: 1;
  color: var(--signal-cyan);
}

.page-about .about-partner__title {
  margin: 0 0 10px;
  font-family: var(--font-emphasis);
  font-weight: 900;
  font-size: 1.05rem;
  letter-spacing: .02em;
  color: var(--pure-white);
}

.page-about .about-partner p {
  max-width: 30em;
  margin: 0;
  font-size: .96rem;
  line-height: 1.85;
  color: var(--text-secondary);
}

.page-about .about-partners__note {
  max-width: 34em;
  margin: 0;
  font-size: .96rem;
  line-height: 1.9;
  color: var(--text-secondary);
}

.page-about .slant-divider {
  margin: clamp(64px, 8vw, 110px) 0 0;
}

/* ---------- 下一步 ---------- */
.page-about .about-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: clamp(22px, 3vw, 32px);
}

.page-about .about-actions__note {
  max-width: 34em;
  margin: var(--space-3) 0 0;
  font-size: .95rem;
  line-height: 1.95;
  color: var(--text-secondary);
}

.page-about .link-arrow {
  white-space: nowrap;
}

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

  .page-about .about-partners {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 860px) {
  .page-about .about-split {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr);
    align-items: start;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 1.45fr) minmax(240px, .55fr);
    align-items: end;
  }

  .page-about .about-hero__figure {
    aspect-ratio: 3 / 4;
  }
}

@media (min-width: 1024px) {
  .page-about .about-body {
    grid-template-columns: minmax(176px, 212px) minmax(0, 1fr);
    column-gap: clamp(40px, 6vw, 88px);
    align-items: start;
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--header-h-compact) + 40px);
    margin: 0;
    padding: 0;
    background-color: transparent;
    border-bottom: 0;
    backdrop-filter: none;
  }

  .page-about .about-rail .index-label {
    display: block;
    margin: 0 0 14px;
    color: var(--index-blue);
    font-family: var(--font-mono);
    letter-spacing: .2em;
  }

  .page-about .about-rail__list {
    display: block;
    overflow: visible;
    padding: 0;
  }

  .page-about .about-rail__list li + li {
    margin-top: 2px;
  }

  .page-about .about-rail__link {
    display: flex;
    justify-content: flex-start;
    padding: 11px 0;
    border: 0;
    border-radius: 0;
    font-size: 14px;
  }
}

@media (min-width: 1280px) {
  .page-about .about-hero__figure {
    aspect-ratio: 3 / 4;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .segmented [role="tab"],
  .page-about .about-rail__link,
  .page-about .timeline__summary::after {
    transition: none;
  }
}