/* ===== 口径与简史 /values/ ===== */

.page-about {
  --about-aside: 196px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(40px, 8vw, 118px) 0 clamp(34px, 5vw, 70px);
  background: var(--paper);
  border-bottom: 2px solid var(--green);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0 0 0 auto;
  width: min(54%, 640px);
  background: linear-gradient(155deg, rgba(11, 61, 46, 0.10), rgba(11, 61, 46, 0) 64%);
  clip-path: polygon(24% 0, 100% 0, 100% 100%, 0 100%);
  pointer-events: none;
}

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

.page-about .breadcrumb {
  margin-bottom: clamp(18px, 3vw, 30px);
  font-size: 0.8125rem;
  line-height: 1.5;
}

.page-about .breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .breadcrumb li + li::before {
  content: "/";
  margin: 0 9px;
  color: var(--silver);
}

.page-about .breadcrumb a {
  color: var(--green);
  text-decoration: none;
  border-bottom: 1px solid var(--green-light);
  transition: border-color 0.18s var(--ease), color 0.18s var(--ease);
}

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

.page-about .about-hero h1 {
  margin: 0 0 22px;
  max-width: 17ch;
  font-size: clamp(2.05rem, 6.2vw, 4.4rem);
  font-weight: 900;
  line-height: 1.06;
  letter-spacing: -0.02em;
  color: var(--green-deep);
}

.page-about .about-hero__lede {
  margin: 0;
  max-width: 60ch;
  font-size: clamp(1rem, 1.5vw, 1.125rem);
  line-height: 1.78;
  color: var(--carbon);
}

.page-about .about-hero__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 9px 26px;
  margin: 28px 0 0;
  padding: 15px 0 0;
  list-style: none;
  border-top: 1px solid var(--line);
  font-size: 0.8125rem;
  line-height: 1.6;
  color: var(--green);
}

.page-about .about-hero__meta li {
  display: flex;
  align-items: center;
  gap: 9px;
}

.page-about .about-hero__meta li::before {
  content: "";
  flex: none;
  width: 14px;
  height: 2px;
  background: var(--orange);
}

/* 章节预览目录 */
.page-about .about-toc {
  margin-top: clamp(32px, 5vw, 60px);
  max-width: 760px;
  border-top: 1px solid var(--line);
}

.page-about .about-toc__list {
  display: grid;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-toc__link {
  display: grid;
  grid-template-columns: 2.4em minmax(0, 1fr);
  gap: 14px;
  align-items: baseline;
  padding: 13px 10px 13px 0;
  border-bottom: 1px solid var(--line);
  color: var(--carbon);
  font-size: 0.9375rem;
  line-height: 1.6;
  text-decoration: none;
  transition: color 0.18s var(--ease), padding-left 0.18s var(--ease), background-color 0.18s var(--ease);
}

.page-about .about-toc__link .idx {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--green);
}

.page-about .about-toc__link:hover,
.page-about .about-toc__link:focus-visible {
  color: var(--green-deep);
  background: var(--gray);
  padding-left: 10px;
}

.page-about .about-toc__link:focus-visible {
  outline: 2px solid var(--blue);
  outline-offset: -2px;
}

/* ---------- 论文式双栏 ---------- */
.page-about .about-chapter {
  position: relative;
  scroll-margin-top: calc(var(--topbar-h) + 18px);
}

.page-about .about-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(18px, 3vw, 32px);
}

.page-about .about-aside {
  display: grid;
  gap: 14px;
  align-content: start;
}

.page-about .about-aside__num {
  margin: 0;
  padding-bottom: 10px;
  border-bottom: 3px solid var(--orange);
  font-family: var(--font-mono);
  font-size: clamp(1.5rem, 4vw, 2rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--green);
}

.page-about .about-aside__note {
  margin: 0;
  font-size: 0.8125rem;
  line-height: 1.72;
  color: var(--green);
  opacity: 0.82;
}

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

.page-about .about-body h2 {
  margin: 0 0 20px;
  max-width: 20ch;
  font-size: clamp(1.5rem, 3.6vw, 2.45rem);
  font-weight: 800;
  line-height: 1.22;
  letter-spacing: -0.01em;
  color: var(--green-deep);
}

.page-about .about-body h3 {
  margin: 0 0 8px;
  font-size: 1.125rem;
  font-weight: 700;
  line-height: 1.4;
  color: var(--green-deep);
}

.page-about .about-body p {
  margin: 0 0 1.15em;
  max-width: 66ch;
  font-size: 1.0625rem;
  line-height: 1.78;
  color: var(--carbon);
}

.page-about .about-body ul,
.page-about .about-body ol {
  margin: 0 0 1.25em;
  padding: 0;
  list-style: none;
}

.page-about .about-body li {
  position: relative;
  padding-left: 20px;
  max-width: 66ch;
  font-size: 1rem;
  line-height: 1.74;
  color: var(--carbon);
}

.page-about .about-body li + li {
  margin-top: 9px;
}

.page-about .about-body li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.68em;
  width: 8px;
  height: 2px;
  background: var(--blue);
}

.page-about .about-body a {
  color: var(--blue);
  text-decoration: none;
  border-bottom: 1px solid rgba(30, 144, 255, 0.35);
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}

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

.page-about .num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.01em;
}

/* 图片 */
.page-about .figure {
  margin: clamp(26px, 4vw, 44px) 0;
}

.page-about .figure__frame {
  aspect-ratio: 3 / 2;
  overflow: hidden;
  background: var(--gray);
  border: 2px solid var(--green-deep);
}

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

.page-about .figure figcaption {
  margin-top: 10px;
  max-width: 62ch;
  font-size: 0.8125rem;
  line-height: 1.68;
  color: var(--green);
  opacity: 0.84;
}

/* 术语定义列表 */
.page-about .about-terms {
  margin: clamp(28px, 4vw, 46px) 0 0;
  padding: 0;
  border-top: 2px solid var(--green-deep);
}

.page-about .about-terms__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 8px;
  padding: 16px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-terms dt {
  margin: 0;
}

.page-about .about-terms dd {
  margin: 0;
  max-width: 62ch;
  font-size: 0.9375rem;
  line-height: 1.72;
  color: var(--carbon);
}

.page-about .about-terms__tag {
  display: inline-block;
  padding: 4px 10px;
  background: var(--paper);
  border: 2px solid var(--green);
  box-shadow: 3px 3px 0 rgba(7, 42, 31, 0.14);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--green);
}

/* ---------- 编年主脊 ---------- */
.page-about .about-chronicle {
  overflow: hidden;
}

.page-about .about-chronicle__bg {
  position: absolute;
  top: 4%;
  right: -14%;
  width: 70%;
  margin: 0;
  opacity: 0.08;
  filter: grayscale(1) contrast(1.15);
  pointer-events: none;
  z-index: 0;
}

.page-about .about-chronicle__bg img {
  display: block;
  width: 100%;
  height: auto;
}

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

/* 阶段刻度尺 */
.page-about .about-scale {
  margin: clamp(26px, 4vw, 42px) 0 clamp(28px, 4vw, 44px);
  overflow-x: auto;
  padding-bottom: 6px;
}

.page-about .about-scale__inner {
  min-width: 520px;
}

.page-about .about-scale__svg {
  display: block;
  width: 100%;
  height: 22px;
  color: var(--green);
}

.page-about .about-scale__labels {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  margin: 8px 0 0;
}

.page-about .about-scale__label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--green);
  text-align: center;
}

/* 时间轴节点 */
.page-about .timeline {
  display: grid;
  gap: clamp(26px, 4vw, 42px);
  margin: clamp(28px, 4vw, 44px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .timeline__item {
  position: relative;
  padding-left: clamp(24px, 3.4vw, 38px);
}

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 8px;
  bottom: 0;
  width: 2px;
  background: var(--silver);
  opacity: 0.75;
}

.page-about .timeline__item::after {
  content: "";
  position: absolute;
  left: 0;
  top: 4px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--paper);
  border: 2px solid var(--silver);
  transition: border-color 0.24s var(--ease), background-color 0.24s var(--ease);
}

.page-about .timeline__item.is-active::before {
  background: var(--orange);
  opacity: 1;
}

.page-about .timeline__item.is-active::after {
  border-color: var(--orange);
  background: var(--orange);
}

.page-about .timeline__item > h3 {
  margin: 0 0 10px;
}

.page-about .about-stage__years {
  display: inline-block;
  margin: 0 0 10px;
  padding: 3px 9px;
  background: var(--orange-light);
  color: var(--green-deep);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.04em;
}

.page-about .about-stage__line {
  margin: 0 0 8px;
  max-width: 64ch;
  font-size: 0.9375rem;
  line-height: 1.74;
  color: var(--carbon);
}

.page-about .about-stage__key {
  display: inline-block;
  min-width: 4.8em;
  margin-right: 8px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--green);
  opacity: 0.82;
}

/* ---------- 赛事收藏边界 ---------- */
.page-about .about-collection__figure {
  margin: clamp(30px, 5vw, 56px) 0 clamp(26px, 4vw, 44px);
}

.page-about .about-collection__figure .figure__frame {
  aspect-ratio: 16 / 9;
}

.page-about .about-panels {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(18px, 2.6vw, 28px);
}

.page-about .about-panel {
  padding: clamp(20px, 2.6vw, 28px);
  background: var(--paper);
  border: 2px solid var(--green-deep);
  box-shadow: var(--shadow-card);
}

.page-about .about-panel h3 {
  margin: 0 0 14px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--green-deep);
  font-size: 1.0625rem;
  font-weight: 800;
  line-height: 1.35;
  letter-spacing: 0.01em;
  color: var(--green-deep);
}

.page-about .about-panel ul {
  display: grid;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-panel li {
  position: relative;
  padding-left: 18px;
  font-size: 0.9375rem;
  line-height: 1.72;
  color: var(--carbon);
}

.page-about .about-panel li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.58em;
  width: 7px;
  height: 7px;
  border: 2px solid var(--green);
}

.page-about .about-field-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .about-field-tags li {
  padding: 5px 12px;
  border: 1px solid var(--green);
  background: var(--green-light);
  color: var(--green-deep);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.03em;
}

.page-about .about-field-tags li::before {
  content: none;
}

/* ---------- 口径核定（深色分区） ---------- */
.page-about .section--dark .about-aside__num {
  color: var(--blue-light);
  border-bottom-color: var(--orange);
}

.page-about .section--dark .about-aside__note {
  color: var(--blue-light);
  opacity: 0.92;
}

.page-about .section--dark .about-body h2 {
  color: var(--paper);
}

.page-about .section--dark .about-body p,
.page-about .section--dark .about-body li {
  color: rgba(244, 241, 232, 0.88);
}

.page-about .section--dark .about-body li::before {
  background: var(--blue-light);
}

.page-about .about-versions {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(18px, 2.6vw, 26px);
  margin: clamp(26px, 4vw, 42px) 0;
}

.page-about .about-version {
  padding: clamp(18px, 2.4vw, 26px);
  background: var(--paper);
  border: 2px solid var(--carbon);
  box-shadow: 6px 6px 0 rgba(0, 0, 0, 0.34);
}

.page-about .about-version--legacy {
  background: var(--gray);
  border-color: var(--silver);
  box-shadow: 6px 6px 0 rgba(192, 192, 192, 0.28);
}

.page-about .about-version__tag {
  margin: 0 0 10px;
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--green);
}

.page-about .about-version__code {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: clamp(1.8rem, 4.4vw, 2.6rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--green-deep);
}

.page-about .about-version__desc {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.72;
  color: var(--carbon);
}

/* ---------- 分工与规模 ---------- */
.page-about .about-roles {
  display: grid;
  gap: 0;
  margin: clamp(24px, 3.4vw, 38px) 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line);
}

.page-about .about-roles > li {
  padding: 20px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-body .about-roles > li {
  padding-left: 0;
}

.page-about .about-body .about-roles > li::before {
  content: none;
}

.page-about .about-roles__num {
  display: block;
  margin-bottom: 7px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--green);
  opacity: 0.8;
}

.page-about .about-roles > li h3 {
  margin-bottom: 6px;
}

.page-about .about-roles > li p {
  margin: 0;
  font-size: 0.9688rem;
  line-height: 1.74;
}

/* ---------- 可引用性 ---------- */
.page-about .about-cite {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 3vw, 32px);
  margin-top: clamp(22px, 3.4vw, 36px);
}

.page-about .about-cite__col {
  padding: clamp(18px, 2.4vw, 26px);
  background: var(--gray);
  border-left: 4px solid var(--green);
}

.page-about .about-cite__col--warn {
  background: var(--orange-light);
  border-left-color: var(--red);
}

.page-about .about-cite__col h3 {
  margin: 0 0 14px;
  padding-bottom: 10px;
  border-bottom: 1px solid rgba(11, 61, 46, 0.24);
  font-size: 1rem;
  font-weight: 800;
  color: var(--green-deep);
}

.page-about .about-cite__col ul {
  display: grid;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-cite__col li {
  position: relative;
  padding-left: 18px;
  font-size: 0.9375rem;
  line-height: 1.72;
  color: var(--carbon);
}

.page-about .about-cite__col li + li {
  margin-top: 0;
}

.page-about .about-cite__col li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.62em;
  width: 8px;
  height: 2px;
  background: var(--green-deep);
}

/* ---------- 勘误行动区 ---------- */
.page-about .about-cta {
  display: grid;
  gap: 22px;
  padding: clamp(24px, 3.2vw, 40px);
  background: var(--green-light);
  border: 2px solid var(--green-deep);
  box-shadow: var(--shadow-card);
}

.page-about .about-cta h2 {
  margin: 0 0 10px;
  font-size: clamp(1.25rem, 2.8vw, 1.75rem);
  font-weight: 800;
  line-height: 1.3;
  color: var(--green-deep);
}

.page-about .about-cta p {
  margin: 0;
  max-width: 58ch;
  font-size: 0.9688rem;
  line-height: 1.74;
  color: var(--carbon);
}

.page-about .about-cta .btn {
  justify-self: start;
}

/* ---------- 断点 ---------- */
@media (min-width: 640px) {
  .page-about .about-terms__row {
    grid-template-columns: 168px minmax(0, 1fr);
    gap: 8px 24px;
    align-items: start;
  }

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

  .page-about .about-version--legacy {
    transform: rotate(-0.7deg);
  }
}

@media (min-width: 768px) {
  .page-about .about-toc__list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: clamp(24px, 4vw, 56px);
  }

  .page-about .about-toc__link {
    border-bottom: 1px solid var(--line);
  }

  .page-about .about-panels {
    grid-template-columns: minmax(0, 1.12fr) minmax(0, 0.88fr);
  }

  .page-about .about-panels > .about-panel--fields {
    grid-column: 1 / -1;
  }

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

  .page-about .about-cta {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: 34px;
  }

  .page-about .about-cta .btn {
    justify-self: end;
  }
}

@media (min-width: 1024px) {
  .page-about .about-row {
    grid-template-columns: var(--about-aside) minmax(0, 1fr);
    column-gap: clamp(20px, 3vw, 40px);
  }

  .page-about .about-aside {
    position: sticky;
    top: clamp(24px, 5vw, 56px);
  }

  .page-about .about-body {
    padding-left: clamp(24px, 3.6vw, 56px);
    border-left: 1px solid var(--line);
  }

  .page-about .about-chronicle__bg {
    right: -8%;
    width: 52%;
  }
}

@media (min-width: 1280px) {
  .page-about {
    --about-aside: 216px;
  }

  .page-about .about-body > p,
  .page-about .about-body > ul,
  .page-about .about-body > ol {
    max-width: 68ch;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-version--legacy {
    transform: none;
  }

  .page-about .timeline__item::after,
  .page-about .about-toc__link {
    transition: none;
  }
}