.page-about {
  --about-rule: rgba(14, 90, 133, 0.18);
  --about-rule-strong: rgba(14, 90, 133, 0.34);
  --about-soft-ink: rgba(36, 28, 22, 0.72);
  background: var(--cream);
  color: var(--ink);
  font-family: var(--font-sans);
}

.page-about .about-cover {
  padding-block: clamp(14px, 3vw, 28px) clamp(30px, 5vw, 56px);
}

.page-about .about-cover-grid {
  display: grid;
  gap: clamp(24px, 4vw, 40px);
  align-items: end;
}

.page-about .about-cover h1 {
  margin: 0.35em 0 0.55em;
  max-width: 15em;
  font-size: clamp(2rem, 6.2vw, 3.6rem);
  font-weight: 600;
  line-height: 1.06;
  letter-spacing: -0.015em;
  color: var(--lake-deep);
}

.page-about .about-cover-lead {
  margin: 0;
  max-width: 36em;
  font-size: clamp(1rem, 1.4vw, 1.08rem);
  line-height: 1.85;
}

.page-about .about-cover-facts {
  display: flex;
  flex-wrap: wrap;
  gap: clamp(18px, 4vw, 44px);
  margin: clamp(22px, 4vw, 32px) 0 0;
  padding: clamp(14px, 2vw, 18px) 0 0;
  list-style: none;
  border-top: 1px solid var(--about-rule-strong);
}

.page-about .about-cover-facts li {
  display: grid;
  gap: 4px;
}

.page-about .about-fact-num {
  font-family: var(--font-mono);
  font-size: clamp(1.3rem, 2.4vw, 1.6rem);
  line-height: 1.1;
  letter-spacing: 0.02em;
  color: var(--lake);
}

.page-about .about-fact-label {
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  color: var(--about-soft-ink);
}

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

.page-about .about-cover-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 10;
  object-fit: cover;
  filter: saturate(0.88) contrast(1.02);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 22px), calc(100% - 22px) 100%, 0 100%);
}

.page-about .about-caption {
  margin-top: 10px;
  font-size: 0.78rem;
  line-height: 1.6;
  letter-spacing: 0.04em;
  color: var(--about-soft-ink);
}

.page-about .about-body {
  display: grid;
  gap: clamp(26px, 4vw, 46px);
  padding-bottom: clamp(40px, 7vw, 96px);
}

.page-about .about-index {
  position: relative;
  padding-left: 24px;
}

.page-about .about-index::before {
  content: "";
  position: absolute;
  left: 0;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: var(--about-rule-strong);
}

.page-about .about-index-label {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.16em;
  color: var(--about-soft-ink);
}

.page-about .about-index-list {
  display: grid;
  gap: 2px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-index-list a {
  position: relative;
  display: flex;
  gap: 10px;
  align-items: baseline;
  padding: 7px 0;
  font-size: 0.92rem;
  line-height: 1.4;
  color: var(--ink);
  text-decoration: none;
  transition: color 0.2s var(--ease);
}

.page-about .about-index-list a::after {
  content: "";
  position: absolute;
  left: -27px;
  top: 15px;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--cream);
  border: 1px solid var(--earth);
  box-sizing: border-box;
}

.page-about .about-index-list a:hover,
.page-about .about-index-list a:focus-visible {
  color: var(--lake);
}

.page-about .about-index-list a:hover::after,
.page-about .about-index-list a:focus-visible::after {
  background: var(--earth);
}

.page-about .about-idx-num {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  color: var(--earth-deep);
}

.page-about .about-flow {
  display: grid;
  gap: clamp(46px, 6vw, 88px);
}

.page-about .about-chapter {
  scroll-margin-top: calc(var(--header-h) + 32px);
}

.page-about .about-chapter-head {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding-bottom: 12px;
  margin-bottom: clamp(18px, 2.6vw, 26px);
  border-bottom: 1px solid var(--about-rule);
}

.page-about .about-chapter-num {
  flex: none;
  position: relative;
  top: -0.1em;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.14em;
  color: var(--earth-deep);
}

.page-about .about-chapter h2 {
  margin: 0;
  font-size: clamp(1.35rem, 3vw, 2rem);
  font-weight: 600;
  line-height: 1.25;
  letter-spacing: -0.01em;
}

.page-about .about-text {
  display: grid;
  gap: 1em;
  max-width: 34em;
  font-size: clamp(1rem, 1.1vw, 1.06rem);
  line-height: 1.85;
}

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

.page-about .about-lead {
  max-width: 32em;
  margin: 0 0 clamp(20px, 3vw, 30px);
  font-size: clamp(1rem, 1.2vw, 1.08rem);
  line-height: 1.85;
  color: var(--ink);
}

.page-about .about-side {
  max-width: 30em;
  margin: clamp(18px, 3vw, 26px) 0 0;
  padding-left: 16px;
  border-left: 2px solid var(--earth);
  font-size: 0.92rem;
  line-height: 1.75;
}

.page-about .about-side a {
  color: var(--lake);
  text-decoration: none;
  border-bottom: 1px solid var(--about-rule-strong);
}

.page-about .about-side a:hover,
.page-about .about-side a:focus-visible {
  border-bottom-color: var(--earth);
}

/* 时间线视图切换 */
.page-about .about-viewtab {
  display: inline-flex;
  gap: 4px;
  padding: 4px;
  margin-bottom: clamp(20px, 3vw, 30px);
  border: 1px solid var(--about-rule-strong);
  border-radius: 999px;
  background: var(--paper);
}

.page-about .about-viewtab label {
  padding: 7px 16px;
  border-radius: 999px;
  font-size: 0.85rem;
  letter-spacing: 0.04em;
  color: var(--about-soft-ink);
  cursor: pointer;
  transition: background 0.2s var(--ease), color 0.2s var(--ease);
}

.page-about .about-viewtab label:hover {
  color: var(--lake-deep);
}

.page-about #about-view-year:checked ~ .about-viewtab label[for="about-view-year"],
.page-about #about-view-theme:checked ~ .about-viewtab label[for="about-view-theme"] {
  background: var(--lake);
  color: var(--paper);
}

.page-about #about-view-year:focus-visible ~ .about-viewtab label[for="about-view-year"],
.page-about #about-view-theme:focus-visible ~ .about-viewtab label[for="about-view-theme"] {
  outline: 2px solid var(--earth);
  outline-offset: 2px;
}

.page-about .about-view--theme {
  display: none;
}

.page-about #about-view-theme:checked ~ .about-view--year {
  display: none;
}

.page-about #about-view-theme:checked ~ .about-view--theme {
  display: block;
}

/* 年份阶段 */
.page-about .about-stages {
  position: relative;
  display: grid;
  gap: clamp(18px, 3vw, 26px);
  margin: 0;
  padding: 0 0 0 28px;
  list-style: none;
}

.page-about .about-stages::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: var(--about-rule-strong);
}

.page-about .about-stage {
  position: relative;
  padding: clamp(16px, 2.4vw, 24px);
  background: var(--paper);
  border: 1px solid var(--about-rule);
  clip-path: polygon(0 0, 100% 0, 100% 100%, 18px 100%, 0 calc(100% - 18px));
  scroll-margin-top: calc(var(--header-h) + 32px);
  transition: border-color 0.25s var(--ease), background 0.25s var(--ease);
}

.page-about .about-stage::before {
  content: "";
  position: absolute;
  left: -28px;
  top: 24px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--cream);
  border: 2px solid var(--earth);
  box-sizing: border-box;
}

.page-about .about-stage:hover {
  border-color: var(--about-rule-strong);
  background: var(--paper);
}

.page-about .about-stage-year {
  display: inline-block;
  padding-bottom: 3px;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 1rem;
  letter-spacing: 0.08em;
  color: var(--earth-deep);
  border-bottom: 2px solid var(--earth);
}

.page-about .about-stage-title {
  margin: 0 0 8px;
  font-size: 1.1rem;
  font-weight: 600;
  line-height: 1.35;
}

.page-about .about-stage-text {
  margin: 0;
  font-size: 0.95rem;
  line-height: 1.8;
}

.page-about .about-stage-kpi {
  margin: 12px 0 0;
  padding-top: 10px;
  border-top: 1px dashed var(--about-rule);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  line-height: 1.6;
  letter-spacing: 0.02em;
  color: var(--about-soft-ink);
  opacity: 0.78;
  transition: opacity 0.25s var(--ease), color 0.25s var(--ease);
}

.page-about .about-stage:hover .about-stage-kpi,
.page-about .about-stage:focus-within .about-stage-kpi {
  opacity: 1;
  color: var(--lake-deep);
}

.page-about .about-timeline-media {
  width: min(100%, 300px);
  margin: clamp(24px, 4vw, 36px) 0 0 auto;
}

.page-about .about-timeline-media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 4;
  object-fit: cover;
  filter: saturate(0.88);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 20px), calc(100% - 20px) 100%, 0 100%);
}

/* 主题视图 */
.page-about .about-theme {
  display: grid;
  gap: clamp(14px, 2.4vw, 22px);
}

.page-about .about-theme-row {
  display: grid;
  gap: 8px;
  padding: clamp(16px, 2.4vw, 22px) clamp(16px, 2.4vw, 24px);
  background: var(--lake-pale);
  clip-path: polygon(0 0, 100% 0, 100% 100%, 18px 100%, 0 calc(100% - 18px));
}

.page-about .about-theme-row h3 {
  margin: 0;
  font-size: 1.06rem;
  font-weight: 600;
}

.page-about .about-theme-row p {
  margin: 0;
  font-size: 0.94rem;
  line-height: 1.78;
}

.page-about .about-theme-years {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.12em;
  color: var(--lake-deep);
}

/* 团队 */
.page-about .about-split {
  display: grid;
  gap: clamp(22px, 3.4vw, 34px);
}

.page-about .about-split-media {
  margin: 0;
}

.page-about .about-split-media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  filter: saturate(0.88);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 20px), calc(100% - 20px) 100%, 0 100%);
}

.page-about .about-lines {
  display: grid;
  gap: 14px;
  margin: clamp(20px, 3vw, 28px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-lines li {
  display: grid;
  gap: 6px;
  padding-left: 14px;
  border-left: 1px solid var(--about-rule-strong);
}

.page-about .about-lines .tag {
  justify-self: start;
}

.page-about .about-lines p {
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.72;
}

/* 数据 */
.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(22px, 3.4vw, 32px) 0 0;
  padding: 0;
  list-style: none;
  background: var(--about-rule);
  border: 1px solid var(--about-rule);
}

.page-about .about-stat {
  display: grid;
  gap: 6px;
  padding: clamp(14px, 2.4vw, 22px);
  background: var(--cream);
}

.page-about .about-stat-num {
  font-family: var(--font-mono);
  font-size: clamp(1.4rem, 3.4vw, 1.95rem);
  line-height: 1;
  letter-spacing: -0.01em;
  color: var(--lake-deep);
}

.page-about .about-stat-label {
  font-size: 0.78rem;
  line-height: 1.5;
  color: var(--about-soft-ink);
}

/* 四条做法 */
.page-about .about-chapter--rules {
  padding: clamp(22px, 3.6vw, 40px);
  background: var(--lake-deep);
  color: var(--cream);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 24px), calc(100% - 24px) 100%, 0 100%);
}

.page-about .about-chapter--rules .about-chapter-head {
  border-bottom-color: rgba(247, 240, 225, 0.28);
}

.page-about .about-chapter--rules .about-chapter-num {
  color: var(--flag-yellow);
}

.page-about .about-chapter--rules h2 {
  color: var(--paper);
}

.page-about .about-chapter--rules .about-lead {
  color: rgba(247, 240, 225, 0.86);
}

.page-about .about-rules {
  display: grid;
  gap: clamp(20px, 3vw, 30px);
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-rule {
  position: relative;
  padding-top: 18px;
  border-top: 1px solid rgba(247, 240, 225, 0.26);
}

.page-about .about-rule::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  width: 42px;
  height: 1px;
  background: var(--earth);
}

.page-about .about-rule-num {
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.16em;
  color: var(--flag-yellow);
}

.page-about .about-rule h3 {
  margin: 0 0 8px;
  font-size: 1.04rem;
  font-weight: 600;
  line-height: 1.4;
  color: var(--paper);
}

.page-about .about-rule p {
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.78;
  color: rgba(247, 240, 225, 0.85);
}

/* 接着看 */
.page-about .about-next {
  padding-top: clamp(24px, 3.6vw, 36px);
  border-top: 1px solid var(--about-rule-strong);
}

.page-about .about-next-title {
  margin: 0 0 clamp(16px, 2.4vw, 22px);
  font-family: var(--font-mono);
  font-size: 0.74rem;
  font-weight: 500;
  letter-spacing: 0.16em;
  color: var(--earth-deep);
}

.page-about .about-next-list {
  display: grid;
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  background: var(--about-rule);
  border: 1px solid var(--about-rule);
}

.page-about .about-next-list a {
  display: grid;
  gap: 4px;
  padding: clamp(14px, 2.2vw, 20px);
  background: var(--cream);
  font-size: 1rem;
  font-weight: 600;
  color: var(--lake-deep);
  text-decoration: none;
  transition: background 0.2s var(--ease), color 0.2s var(--ease);
}

.page-about .about-next-list a span {
  font-size: 0.82rem;
  font-weight: 400;
  line-height: 1.6;
  color: var(--about-soft-ink);
}

.page-about .about-next-list a:hover,
.page-about .about-next-list a:focus-visible {
  background: var(--lake-pale);
}

@media (min-width: 640px) {
  .page-about .about-next-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

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

  .page-about .about-rules {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: clamp(28px, 4vw, 52px);
  }
}

@media (min-width: 820px) {
  .page-about .about-split {
    grid-template-columns: minmax(0, 1.3fr) minmax(0, 0.7fr);
    align-items: start;
    gap: clamp(24px, 4vw, 44px);
  }
}

@media (min-width: 900px) {
  .page-about .about-cover-grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    gap: clamp(32px, 5vw, 60px);
  }

  .page-about .about-body {
    grid-template-columns: 180px minmax(0, 1fr);
    gap: clamp(32px, 5vw, 72px);
  }

  .page-about .about-index {
    position: sticky;
    top: calc(var(--header-h) + 24px);
    align-self: start;
  }
}

@media (min-width: 1000px) {
  .page-about .about-stage:nth-child(even) {
    margin-left: 64px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-index-list a,
  .page-about .about-stage,
  .page-about .about-stage-kpi,
  .page-about .about-viewtab label,
  .page-about .about-next-list a {
    transition-duration: 0.01ms;
  }
}
</main>