.page-about {
  --about-aside: 300px;
  --about-col-gap: clamp(28px, 4.5vw, 68px);
  --about-section-gap: clamp(40px, 6vw, 80px);
  padding-bottom: clamp(48px, 8vw, 96px);
}

/* ---------- 页头分屏 ---------- */
.page-about .about-hero {
  padding-top: clamp(20px, 3vw, 36px);
  padding-bottom: clamp(32px, 5vw, 64px);
  border-bottom: 2px solid var(--line);
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 4vw, 48px);
  align-items: end;
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr);
    gap: clamp(32px, 5vw, 72px);
  }
}

.page-about .about-hero__title {
  font-family: var(--font-display);
  font-weight: 300;
  font-size: clamp(32px, 6vw, 68px);
  line-height: 1.06;
  letter-spacing: -0.01em;
  color: var(--paper);
  margin: 14px 0 20px;
  max-width: 12em;
}

.page-about .about-hero__note {
  max-width: 34em;
  color: var(--mist);
  margin: 0 0 24px;
}

.page-about .about-hero__stats {
  margin-top: 8px;
  gap: clamp(24px, 4vw, 48px);
}

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

.page-about .about-hero__figure img {
  max-width: 100%;
  height: auto;
  object-fit: cover;
  filter: saturate(0.8) contrast(1.05);
}

/* ---------- 主体两栏 ---------- */
.page-about .about-body {
  padding-top: clamp(32px, 5vw, 72px);
}

.page-about .about-body__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(28px, 4vw, 44px);
}

@media (min-width: 980px) {
  .page-about .about-body__grid {
    grid-template-columns: var(--about-aside) minmax(0, 1fr);
    gap: var(--about-col-gap);
    align-items: start;
  }
}

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

/* ---------- 左侧吸顶索引 ---------- */
.page-about .about-index__sticky {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  padding: 20px 18px 26px;
  background: var(--ink-2);
  border: 2px solid var(--line);
}

@media (min-width: 980px) {
  .page-about .about-index__sticky {
    position: sticky;
    top: 118px;
  }
}

.page-about .about-index__texture {
  position: absolute;
  inset: 0;
  z-index: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.14;
  filter: grayscale(1) contrast(1.2);
  pointer-events: none;
}

.page-about .about-index__sticky > *:not(.about-index__texture) {
  position: relative;
  z-index: 1;
}

.page-about .about-index__label {
  color: var(--lime);
  letter-spacing: 0.22em;
  margin: 0;
}

.page-about .about-index__list {
  list-style: none;
  margin: 14px 0 0;
  padding: 0;
  display: flex;
  flex-direction: column;
}

.page-about .about-index__list a {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 10px 8px 10px 10px;
  color: var(--text);
  font-size: 14px;
  line-height: 1.4;
  text-decoration: none;
  border-left: 2px solid transparent;
  transition: color var(--t), border-color var(--t), background var(--t);
}

.page-about .about-index__list a:hover,
.page-about .about-index__list a:focus-visible {
  color: var(--lime);
  border-left-color: var(--lime);
  background: rgba(200, 255, 77, 0.07);
  outline: none;
}

.page-about .about-index__num {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--mist);
  flex: none;
}

.page-about .about-index__meter {
  position: relative;
  height: 3px;
  margin-top: 20px;
  background: var(--line);
}

.page-about .about-index__meter > span {
  display: block;
  height: 100%;
  width: 0;
  background: var(--lime);
  transition: width 0.2s var(--ease);
}

/* ---------- 章节骨架 ---------- */
.page-about .about-section {
  padding-top: clamp(26px, 4vw, 44px);
  margin-top: var(--about-section-gap);
  border-top: 1px solid var(--line);
  scroll-margin-top: 132px;
}

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

.page-about .about-section__head {
  display: flex;
  align-items: flex-start;
  gap: clamp(12px, 2vw, 20px);
  margin-bottom: 20px;
}

.page-about .about-section__num {
  flex: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--lime);
  padding-top: 8px;
  border-top: 2px solid var(--lime);
}

.page-about .about-section__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 300;
  font-size: clamp(24px, 3.4vw, 42px);
  line-height: 1.12;
  letter-spacing: -0.005em;
  color: var(--paper);
}

/* ---------- 正文 ---------- */
.page-about .prose p {
  color: var(--text);
  font-size: 17px;
  line-height: 1.78;
  letter-spacing: 0.01em;
  max-width: 680px;
  margin: 0 0 18px;
}

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

.page-about .about-note {
  max-width: 560px;
  border-left: 3px solid var(--lime);
  padding: 6px 0 6px 16px;
  color: var(--mist);
  font-size: 14px;
  line-height: 1.75;
  margin: 24px 0 0;
}

/* ---------- 标签页 ---------- */
.page-about .about-tabs {
  margin-top: 30px;
  border: 2px solid var(--noir);
  background: var(--ink-2);
}

.page-about .tablist {
  display: flex;
  flex-wrap: wrap;
  background: var(--ink);
  border-bottom: 2px solid var(--noir);
}

.page-about .tab {
  flex: 1 1 auto;
  min-width: 118px;
  padding: 14px 16px;
  font-family: var(--font-display);
  font-size: 13px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--mist);
  background: transparent;
  border: 0;
  border-right: 1px solid var(--line);
  cursor: pointer;
  transition: color var(--t), background var(--t);
}

.page-about .tab:last-child {
  border-right: 0;
}

.page-about .tab:hover {
  color: var(--lime);
}

.page-about .tab[aria-selected="true"] {
  color: var(--ink);
  background: var(--lime);
}

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

.page-about .tabpanel {
  padding: clamp(20px, 3vw, 32px);
}

.page-about .tabpanel:focus-visible {
  outline: 2px solid var(--lime);
  outline-offset: -4px;
}

.page-about .about-panel__lead {
  font-family: var(--font-display);
  font-size: 19px;
  letter-spacing: 0.03em;
  color: var(--lime);
  margin: 0 0 12px;
}

.page-about .tabpanel > p {
  color: var(--text);
  font-size: 16px;
  line-height: 1.76;
  max-width: 640px;
  margin: 0 0 18px;
}

.page-about .about-bullets {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .about-bullets li {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 16px;
  padding: 11px 0;
  border-bottom: 1px solid var(--line-soft);
  color: var(--text);
  font-size: 14px;
  line-height: 1.6;
}

.page-about .about-bullets__k {
  flex: none;
  min-width: 66px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--cyan);
  padding-top: 3px;
}

/* ---------- 编辑与校对 ---------- */
.page-about .about-editorial {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(20px, 3vw, 36px);
  margin-bottom: 30px;
}

@media (min-width: 760px) {
  .page-about .about-editorial {
    grid-template-columns: minmax(0, 220px) minmax(0, 1fr);
    align-items: start;
  }
}

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

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

.page-about .about-editorial__text p:first-child {
  margin-top: 0;
}

/* ---------- 米白纸面模块 ---------- */
.page-about .about-slab {
  border: 3px solid var(--noir);
  box-shadow: 8px 8px 0 var(--shadow-block);
  padding: clamp(20px, 3vw, 32px);
  background: var(--paper);
  color: var(--noir);
}

.page-about .about-slab + .about-slab {
  margin-top: 30px;
}

.page-about .about-slab__cap {
  margin: 0 0 14px;
  color: var(--rust);
  letter-spacing: 0.2em;
}

.page-about .about-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 15px;
}

.page-about .about-table caption {
  text-align: left;
  font-family: var(--font-display);
  font-size: 13px;
  letter-spacing: 0.12em;
  color: var(--noir);
  padding-bottom: 12px;
}

.page-about .about-table th,
.page-about .about-table td {
  text-align: left;
  padding: 11px 12px;
  border-bottom: 1px solid rgba(21, 16, 12, 0.16);
  vertical-align: top;
}

.page-about .about-table thead th {
  font-family: var(--font-display);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  border-bottom: 2px solid var(--noir);
}

.page-about .about-table tbody tr:nth-child(even) {
  background: rgba(21, 16, 12, 0.05);
}

.page-about .about-table .num {
  font-family: var(--font-mono);
  font-size: 17px;
  width: 68px;
}

/* ---------- 流程图 ---------- */
.page-about .about-svg {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .about-svg__box {
  fill: none;
  stroke: var(--noir);
  stroke-width: 2;
}

.page-about .about-svg__box--lime {
  fill: var(--lime);
}

.page-about .about-svg__label {
  fill: var(--noir);
  font-family: var(--font-display);
  font-size: 15px;
  letter-spacing: 0.04em;
}

.page-about .about-svg__tag {
  fill: var(--rust);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
}

.page-about .about-svg__line {
  fill: none;
  stroke: var(--noir);
  stroke-width: 2;
}

.page-about .about-diagram__note {
  margin: 16px 0 0;
  color: var(--noir);
  font-size: 14px;
  line-height: 1.72;
  max-width: 620px;
}

/* ---------- 版本时间轴 ---------- */
.page-about .about-timeline {
  list-style: none;
  margin: 32px 0 0;
  padding: 0;
  border-top: 2px solid var(--line);
}

.page-about .about-timeline__item {
  display: grid;
  grid-template-columns: 1fr;
  gap: 8px;
  padding: 20px 0 20px 20px;
  border-bottom: 1px solid var(--line);
  border-left: 2px solid transparent;
  transition: border-color var(--t), background var(--t);
}

.page-about .about-timeline__item:hover {
  border-left-color: var(--lime);
  background: linear-gradient(90deg, rgba(200, 255, 77, 0.06), transparent 62%);
}

@media (min-width: 720px) {
  .page-about .about-timeline__item {
    grid-template-columns: 130px minmax(0, 1fr);
    gap: 28px;
    align-items: start;
    padding-left: 18px;
  }
}

.page-about .about-timeline__year {
  font-family: var(--font-mono);
  font-size: clamp(20px, 2.6vw, 28px);
  line-height: 1.1;
  color: var(--lime);
  letter-spacing: 0.02em;
}

.page-about .about-timeline__title {
  font-family: var(--font-display);
  font-weight: 400;
  font-size: 20px;
  letter-spacing: 0.02em;
  color: var(--paper);
  margin: 0 0 8px;
}

.page-about .about-timeline__body p {
  margin: 0;
  color: var(--text);
  font-size: 16px;
  line-height: 1.74;
  max-width: 620px;
}

/* ---------- 动作区 ---------- */
.page-about .about-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

/* ---------- 响应式收尾 ---------- */
@media (max-width: 560px) {
  .page-about .about-hero__title {
    font-size: clamp(28px, 8.6vw, 40px);
    max-width: none;
  }

  .page-about .tab {
    flex: 1 1 100%;
    border-right: 0;
    border-bottom: 1px solid var(--line);
    text-align: left;
  }

  .page-about .about-table th,
  .page-about .about-table td {
    padding: 9px 8px;
    font-size: 14px;
  }

  .page-about .about-slab {
    box-shadow: 5px 5px 0 var(--shadow-block);
  }
}

.page-about img {
  max-width: 100%;
  height: auto;
}

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