.page-about {
  --about-rail: 108px;
  --about-scan: repeating-linear-gradient(
    180deg,
    rgba(234, 243, 241, 0.028) 0 1px,
    transparent 1px 4px
  );
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumb {
  padding-top: clamp(14px, 2.4vw, 24px);
}

.page-about .breadcrumb ol {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--muted);
}

.page-about .breadcrumb li {
  display: flex;
  align-items: center;
  gap: 6px;
}

.page-about .breadcrumb li + li::before {
  content: "/";
  color: var(--edge);
}

.page-about .breadcrumb a {
  color: var(--muted);
  text-decoration: none;
  transition: color 0.2s ease;
}

.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible {
  color: var(--live);
}

.page-about .breadcrumb [aria-current="page"] {
  color: var(--season);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  margin-top: clamp(14px, 2.2vw, 22px);
  padding-block: clamp(30px, 6vw, 74px) clamp(26px, 4.4vw, 52px);
  border-top: 1px solid var(--edge);
  border-bottom: 1px solid var(--edge);
  background: var(--ink);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background:
    radial-gradient(130% 90% at 6% -20%, rgba(23, 224, 176, 0.16), transparent 60%),
    radial-gradient(85% 80% at 100% 8%, rgba(240, 168, 60, 0.12), transparent 62%);
  pointer-events: none;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background: var(--about-scan);
  pointer-events: none;
}

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

.page-about .about-hero__title {
  margin: 14px 0 0;
  font-family: var(--sans);
  font-weight: 700;
  font-size: clamp(28px, 5.2vw, 54px);
  line-height: 1.14;
  letter-spacing: -0.022em;
  color: var(--text);
}

.page-about .about-hero__lead {
  margin: clamp(16px, 2.4vw, 24px) 0 0;
  max-width: 44em;
  font-size: clamp(15px, 1.5vw, 17.5px);
  line-height: 1.85;
  color: var(--muted);
}

.page-about .about-hero__facts {
  list-style: none;
  margin: clamp(26px, 4vw, 46px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  border: 1px solid var(--edge);
  background: var(--edge);
}

.page-about .about-hero__facts li {
  display: flex;
  flex-direction: column;
  gap: 7px;
  padding: 16px 16px 18px;
  background: rgba(12, 43, 42, 0.72);
}

.page-about .about-fact__value {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(26px, 3.6vw, 38px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--live);
}

.page-about .about-fact--season .about-fact__value {
  color: var(--season);
}

.page-about .about-fact__label {
  font-size: 12.5px;
  line-height: 1.65;
  color: var(--muted);
}

/* ---------- 主体双栏 ---------- */
.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 3vw, 40px);
  padding-block: clamp(24px, 4vw, 56px) clamp(44px, 6vw, 84px);
}

.page-about .about-rail {
  border-top: 1px solid var(--edge);
  padding-top: 14px;
}

.page-about .about-rail__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 6px 12px;
}

.page-about .about-rail__link {
  display: inline-flex;
  align-items: baseline;
  gap: 7px;
  padding: 5px 8px;
  border-radius: var(--radius);
  color: var(--muted);
  font-size: 13px;
  text-decoration: none;
  transition: color 0.2s ease, background-color 0.2s ease;
}

.page-about .about-rail__link .num {
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: 0.06em;
  color: var(--season);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  color: var(--text);
  background: rgba(23, 224, 176, 0.1);
}

.page-about .about-rail__note {
  display: none;
}

/* ---------- 章节 ---------- */
.page-about .about-chapter {
  padding-block: clamp(26px, 4vw, 46px);
  border-top: 1px solid var(--edge);
}

.page-about .about-chapter:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .about-chapter__title {
  margin: 10px 0 0;
  font-family: var(--sans);
  font-size: clamp(22px, 3.2vw, 34px);
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.012em;
  color: var(--text);
}

.page-about .about-chapter__title::after {
  content: "";
  display: block;
  width: 40px;
  height: 2px;
  margin-top: 14px;
  background: linear-gradient(90deg, var(--live), var(--season));
  opacity: 0.45;
  transition: width 0.32s ease, opacity 0.32s ease;
}

.page-about .about-chapter.is-revealed .about-chapter__title::after {
  width: 76px;
  opacity: 1;
}

.page-about .prose {
  margin-top: clamp(14px, 2.2vw, 22px);
}

.page-about .prose p {
  margin: 0 0 14px;
  max-width: 46em;
  font-size: clamp(15px, 1.4vw, 17px);
  line-height: 1.85;
  color: var(--text);
}

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

/* ---------- 时间轴 ---------- */
.page-about .about-timeline {
  list-style: none;
  margin: clamp(20px, 3vw, 30px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  border: 1px solid var(--edge);
  background: var(--edge);
}

.page-about .about-timeline__item {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 18px 16px 20px;
  background: var(--panel);
}

.page-about .about-timeline__item--now {
  background: var(--panel-2);
}

.page-about .about-timeline__year {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--season);
}

.page-about .about-timeline__item--now .about-timeline__year {
  color: var(--live);
}

.page-about .about-timeline__text {
  font-size: 13.5px;
  line-height: 1.78;
  color: var(--muted);
}

/* ---------- 图片框 ---------- */
.page-about .about-figure,
.page-about .about-partner-media {
  margin: clamp(18px, 2.6vw, 28px) 0 0;
}

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

.page-about .about-figure img,
.page-about .about-archive__media img,
.page-about .about-partner-media img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
}

/* ---------- 一轮流程 ---------- */
.page-about .about-flow {
  list-style: none;
  margin: clamp(18px, 2.6vw, 26px) 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-flow__item {
  display: grid;
  grid-template-columns: 32px minmax(0, 1fr);
  gap: 12px;
  align-items: start;
  padding: 13px 14px;
  border-left: 2px solid var(--edge);
  background: rgba(16, 61, 58, 0.34);
}

.page-about .about-flow__item:nth-child(1) {
  border-left-color: var(--season);
}

.page-about .about-flow__item:nth-child(2) {
  border-left-color: var(--live);
}

.page-about .about-flow__item:nth-child(3) {
  border-left-color: var(--live-soft);
}

.page-about .about-flow__step {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--muted);
  padding-top: 3px;
}

.page-about .about-flow__body {
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-flow__body strong {
  color: var(--text);
  font-weight: 600;
}

/* ---------- 档案布局 ---------- */
.page-about .about-archive {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(18px, 3vw, 32px);
  margin-top: clamp(16px, 2.4vw, 24px);
}

.page-about .about-archive__facts {
  list-style: none;
  margin: clamp(16px, 2.4vw, 22px) 0 0;
  padding: 0;
  display: grid;
  gap: 9px;
}

.page-about .about-archive__facts li {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding-bottom: 9px;
  border-bottom: 1px dashed rgba(31, 79, 75, 0.85);
  font-size: 14px;
  line-height: 1.7;
  color: var(--text);
}

.page-about .about-archive__facts .num {
  flex: 0 0 auto;
  min-width: 4.5ch;
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: 17px;
  font-weight: 700;
  color: var(--season);
}

.page-about .about-disclosures {
  margin-top: clamp(16px, 2.4vw, 24px);
  display: grid;
  gap: 8px;
}

.page-about .about-disclosure__btn {
  width: 100%;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 13px 14px;
  border: 1px solid var(--edge);
  border-radius: var(--radius);
  background: var(--panel-2);
  color: var(--text);
  font: inherit;
  font-size: 14.5px;
  text-align: left;
  cursor: pointer;
  transition: border-color 0.2s ease, background-color 0.2s ease;
}

.page-about .about-disclosure__btn:hover {
  border-color: var(--live);
}

.page-about .about-disclosure__btn:focus-visible {
  outline: 2px solid var(--live-soft);
  outline-offset: 2px;
}

.page-about .about-disclosure__btn[aria-expanded="true"] {
  border-color: var(--live);
  background: rgba(23, 224, 176, 0.09);
}

.page-about .about-disclosure__title {
  flex: 1 1 auto;
  font-weight: 600;
}

.page-about .about-disclosure__meta {
  flex: 0 0 auto;
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: 12.5px;
  color: var(--season);
  white-space: nowrap;
}

.page-about .about-disclosure__icon {
  position: relative;
  flex: 0 0 auto;
  width: 14px;
  height: 14px;
}

.page-about .about-disclosure__icon::before,
.page-about .about-disclosure__icon::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 50%;
  height: 1.5px;
  background: var(--live);
  transform: translateY(-50%);
}

.page-about .about-disclosure__icon::after {
  transform: translateY(-50%) rotate(90deg);
  transition: transform 0.24s ease;
}

.page-about .about-disclosure__btn[aria-expanded="true"] .about-disclosure__icon::after {
  transform: translateY(-50%) rotate(0deg);
}

.page-about .about-disclosure__panel {
  margin: 8px 0 0 14px;
  padding: 4px 0 4px 14px;
  border-left: 2px solid var(--edge);
  font-size: 14px;
  line-height: 1.82;
  color: var(--muted);
}

.page-about .about-disclosure__panel p {
  margin: 0;
}

/* ---------- 伙伴 ---------- */
.page-about .about-partners {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin-top: clamp(18px, 2.6vw, 26px);
  border: 1px solid var(--edge);
  background: var(--edge);
}

.page-about .about-partners__item {
  padding: 18px 16px 20px;
  background: var(--panel);
}

.page-about .about-partners__item h3 {
  margin: 0 0 8px;
  font-size: 15.5px;
  font-weight: 600;
  color: var(--live);
}

.page-about .about-partners__item p {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.78;
  color: var(--muted);
}

/* ---------- 年度节奏 ---------- */
.page-about .about-rhythm {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin-top: clamp(18px, 2.6vw, 26px);
  border: 1px solid var(--edge);
  background: var(--edge);
}

.page-about .about-rhythm__card {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 20px 18px 22px;
  background: var(--panel-2);
}

.page-about .about-rhythm__tag {
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: 0.14em;
  color: var(--season);
}

.page-about .about-rhythm__card h3 {
  margin: 0;
  font-size: 17px;
  font-weight: 600;
  line-height: 1.4;
  color: var(--text);
}

.page-about .about-rhythm__card p {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 章节出口 ---------- */
.page-about .about-next {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 14px;
  margin-top: clamp(26px, 4vw, 40px);
  padding-top: clamp(18px, 2.6vw, 26px);
  border-top: 1px solid var(--edge);
}

.page-about .about-next__label {
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: 0.16em;
  color: var(--muted);
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-hero__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

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

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

@media (min-width: 900px) {
  .page-about .about-archive {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr);
    align-items: start;
  }
}

@media (min-width: 1040px) {
  .page-about .about-body {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: clamp(28px, 4vw, 64px);
  }

  .page-about .about-rail {
    border-top: 0;
    padding-top: 0;
  }

  .page-about .about-rail__inner {
    position: sticky;
    top: clamp(84px, 12vh, 128px);
  }

  .page-about .about-rail__list {
    flex-direction: column;
    flex-wrap: nowrap;
    gap: 2px;
    border-left: 1px solid var(--edge);
  }

  .page-about .about-rail__link {
    flex-direction: column;
    align-items: flex-start;
    gap: 3px;
    padding: 9px 0 9px 14px;
    border-left: 2px solid transparent;
    border-radius: 0;
  }

  .page-about .about-rail__link:hover,
  .page-about .about-rail__link:focus-visible {
    background: transparent;
    border-left-color: var(--live);
  }

  .page-about .about-rail__note {
    display: block;
    writing-mode: vertical-rl;
    margin: 32px 0 0 auto;
    font-family: var(--mono);
    font-size: 11.5px;
    letter-spacing: 0.2em;
    color: var(--season);
    opacity: 0.78;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }
}