.page-about {
  background: var(--bg);
}

/* ===== Hero ===== */
.page-about .about-hero {
  padding: 28px 0 8px;
}

.page-about .about-hero__top {
  max-width: 760px;
  margin-bottom: 24px;
}

.page-about .about-hero__title {
  font-family: var(--font-title);
  font-size: 34px;
  line-height: 1.15;
  color: var(--ink);
  margin: 8px 0 14px;
  letter-spacing: -0.02em;
}

.page-about .about-hero__lead {
  font-size: 15px;
  line-height: 1.78;
  color: var(--rock);
  margin: 0;
}

.page-about .about-hero__image {
  position: relative;
  margin: 0;
  border: 1px solid var(--ink);
  box-shadow: 8px 8px 0 var(--paper-dark);
  background: var(--paper-dark);
}

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

.page-about .about-hero__caption {
  margin: 8px 12px 10px;
  font-family: var(--font-data);
  font-size: 12px;
  color: var(--rock);
  letter-spacing: 0.04em;
}

/* ===== 手册式布局 ===== */
.page-about .about-layout {
  display: grid;
  gap: 36px;
  padding: 48px 0 72px;
}

.page-about .about-index {
  position: relative;
  align-self: start;
  padding: 20px;
  background: var(--paper-dark);
  border: 1px solid var(--ink);
  box-shadow: 5px 5px 0 var(--rock);
}

.page-about .about-index::before {
  content: '';
  position: absolute;
  inset: 4px;
  border: 1px solid var(--sage);
  pointer-events: none;
}

.page-about .about-index__label {
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--terracotta);
  margin: 0 0 14px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--ink);
}

.page-about .about-index__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 4px;
}

.page-about .about-index__list a {
  display: block;
  padding: 8px 6px;
  color: var(--ink);
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
  border-left: 3px solid transparent;
  transition: border-color 0.2s ease, background 0.2s ease;
}

.page-about .about-index__list a:hover,
.page-about .about-index__list a:focus-visible {
  border-left-color: var(--terracotta);
  background: rgba(197, 106, 74, 0.1);
}

.page-about .about-index__note {
  display: none;
  margin-top: 18px;
  padding-top: 12px;
  border-top: 1px solid var(--rock);
  justify-content: space-between;
  font-family: var(--font-data);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--rock);
  text-transform: uppercase;
}

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

.page-about .about-section {
  scroll-margin-top: 120px;
}

.page-about .about-section + .about-section {
  margin-top: 64px;
}

.page-about .about-section .section-head {
  margin-bottom: 24px;
}

/* ===== 品牌定位 ===== */
.page-about .about-positioning__grid {
  display: grid;
  gap: 20px;
}

.page-about .about-positioning__main {
  padding: 24px;
}

.page-about .about-positioning__paragraph {
  font-size: 15px;
  line-height: 1.82;
  color: var(--rock);
  margin: 0;
}

.page-about .about-positioning__paragraph + .about-positioning__paragraph {
  margin-top: 14px;
}

.page-about .about-positioning__cta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 16px;
  margin: 20px 0 0;
}

.page-about .about-text-link {
  font-size: 14px;
  font-weight: 600;
  color: var(--moss);
  text-decoration: none;
  border-bottom: 1px solid var(--sage);
  transition: color 0.2s ease, border-color 0.2s ease;
}

.page-about .about-text-link:hover {
  color: var(--terracotta);
  border-bottom-color: var(--terracotta);
}

.page-about .about-positioning__aside {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

.page-about .about-positioning__card {
  padding: 20px;
}

.page-about .about-positioning__card .data-label {
  margin: 0 0 6px;
}

.page-about .about-positioning__card .data-num--lg {
  font-size: 38px;
  line-height: 1.1;
  margin: 0 0 12px;
}

.page-about .about-positioning__card .data-num--lg:last-child {
  margin-bottom: 0;
}

.page-about .about-positioning__card.card--dark .data-label {
  color: var(--sage);
}

.page-about .about-positioning__card.card--dark .data-num {
  color: var(--data-green);
}

.page-about .about-unit {
  font-size: 0.48em;
  font-weight: 400;
  margin-left: 3px;
  color: inherit;
}

/* ===== 版本演进时间线 ===== */
.page-about .about-timeline {
  position: relative;
}

.page-about .about-timeline__item {
  position: relative;
  padding: 0 0 28px 32px;
}

.page-about .about-timeline__item:last-child {
  padding-bottom: 0;
}

.page-about .about-timeline__item::before {
  content: '';
  position: absolute;
  left: 6px;
  top: 20px;
  bottom: -4px;
  width: 2px;
  background: var(--sage);
}

.page-about .about-timeline__item:last-child::before {
  display: none;
}

.page-about .about-timeline__marker {
  position: absolute;
  left: 0;
  top: 20px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--terracotta);
  border: 3px solid var(--bg);
  box-shadow: 0 0 0 2px var(--terracotta);
}

.page-about .about-timeline__content {
  padding: 20px;
}

.page-about .about-timeline__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
  margin-bottom: 8px;
}

.page-about .about-timeline__range {
  font-family: var(--font-data);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--terracotta);
}

.page-about .about-timeline__title {
  font-family: var(--font-title);
  font-size: 20px;
  line-height: 1.4;
  color: var(--ink);
  margin: 4px 0 8px;
}

.page-about .about-timeline__desc {
  font-size: 14px;
  line-height: 1.75;
  color: var(--rock);
  margin: 0;
}

/* ===== 数据规模 ===== */
.page-about .about-scale-grid {
  display: grid;
  gap: 24px;
}

.page-about .about-scale-grid__stats {
  padding: 24px;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px 16px;
}

.page-about .about-stat .data-label {
  color: var(--sage);
  margin: 0 0 6px;
}

.page-about .about-stat .data-num {
  font-family: var(--font-data);
  font-size: 32px;
  font-weight: 700;
  line-height: 1.2;
  color: var(--data-green);
  margin: 0;
}

.page-about .about-scale-grid__figure {
  position: relative;
  margin: 0;
  overflow: hidden;
  aspect-ratio: 8 / 5;
  border: 1px solid var(--ink);
  background: var(--paper-dark);
}

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

.page-about .about-scale-grid__caption {
  position: absolute;
  left: 12px;
  right: 12px;
  bottom: 12px;
  margin: 0;
  padding: 8px 12px;
  background: rgba(26, 25, 23, 0.84);
  color: var(--bg);
  font-size: 12px;
  font-family: var(--font-body);
  line-height: 1.5;
}

.page-about .about-update {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-top: 24px;
  padding: 16px 20px;
}

.page-about .about-update__icon {
  width: 40px;
  height: 40px;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--paper-dark);
  border: 1px solid var(--ink);
}

.page-about .about-update .data-label {
  margin: 0;
}

.page-about .about-update__desc {
  margin: 4px 0 0;
  font-size: 15px;
  line-height: 1.65;
  color: var(--rock);
}

.page-about .about-update__desc strong {
  font-family: var(--font-data);
  font-size: 14px;
  color: var(--ink);
}

/* ===== 服务原则 ===== */
.page-about .about-principles {
  display: grid;
  gap: 24px;
}

.page-about .about-principles__panel {
  padding: 20px;
  background: var(--paper-dark);
  border: 1px solid var(--ink);
  box-shadow: 5px 5px 0 var(--rock);
}

.page-about .about-principles__panel .tab-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  margin: 0 0 20px;
  padding: 0 0 12px;
  border-bottom: 2px solid var(--ink);
}

.page-about .about-principles__panel .tab-button {
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 600;
  padding: 8px 14px;
  background: transparent;
  border: 1px solid var(--rock);
  color: var(--rock);
  cursor: pointer;
  transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.page-about .about-principles__panel .tab-button:hover {
  background: var(--clay);
  border-color: var(--clay);
}

.page-about .about-principles__panel .tab-button:focus-visible {
  outline: 2px solid var(--signal-orange);
  outline-offset: 2px;
}

.page-about .about-principles__panel .tab-button[aria-selected='true'] {
  background: var(--moss);
  border-color: var(--moss);
  color: var(--bg);
}

.page-about .about-principles__panel .tab-panel {
  background: var(--bg);
  border: 1px solid var(--rock);
  padding: 20px;
  box-shadow: none;
}

.page-about .about-principles__panel-title {
  font-family: var(--font-title);
  font-size: 22px;
  color: var(--ink);
  margin: 0 0 10px;
}

.page-about .about-principles__desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--rock);
}

.page-about .about-principles__figure {
  position: relative;
  margin: 0;
  overflow: hidden;
  aspect-ratio: 1 / 1;
  border: 1px solid var(--ink);
  background: var(--paper-dark);
}

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

.page-about .about-principles__caption {
  position: absolute;
  left: 12px;
  right: 12px;
  bottom: 12px;
  margin: 0;
  padding: 8px 12px;
  background: rgba(26, 25, 23, 0.84);
  color: var(--bg);
  font-size: 12px;
  font-family: var(--font-body);
  line-height: 1.5;
}

.page-about .about-award {
  margin-top: 32px;
  padding: 20px 24px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px;
  background: var(--paper-dark);
  border-left: 4px solid var(--terracotta);
}

.page-about .about-award__badge {
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: 0.08em;
  padding: 4px 10px;
  background: var(--terracotta);
  color: var(--bg);
}

.page-about .about-award__text {
  margin: 0;
  font-size: 15px;
  font-weight: 700;
  color: var(--ink);
}

.page-about .about-award .data-label {
  flex-basis: 100%;
  color: var(--rock);
}

/* ===== 结束链接 ===== */
.page-about .about-end-links {
  margin-top: 28px;
  text-align: center;
  font-size: 14px;
  line-height: 2;
  color: var(--rock);
}

.page-about .about-end-links a {
  color: var(--moss);
  font-weight: 600;
  text-decoration: none;
  border-bottom: 1px solid var(--sage);
  transition: color 0.2s ease, border-bottom-color 0.2s ease;
}

.page-about .about-end-links a:hover {
  color: var(--terracotta);
  border-bottom-color: var(--terracotta);
}

/* ===== 平板 ===== */
@media (min-width: 768px) {
  .page-about .about-hero {
    padding-top: 36px;
  }

  .page-about .about-hero__title {
    font-size: 44px;
  }

  .page-about .about-hero__lead {
    font-size: 16px;
  }

  .page-about .about-index__list {
    grid-template-columns: repeat(4, 1fr);
  }

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

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

  .page-about .about-timeline__item {
    padding-left: 56px;
  }

  .page-about .about-timeline__item::before {
    left: 25px;
  }

  .page-about .about-timeline__marker {
    left: 18px;
    top: 18px;
    width: 16px;
    height: 16px;
  }

  .page-about .about-scale-grid {
    grid-template-columns: 1fr 1fr;
  }

  .page-about .about-update {
    grid-column: 1 / -1;
    margin-top: 0;
  }

  .page-about .about-principles {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
  }

  .page-about .about-principles__figure {
    height: 100%;
  }
}

/* ===== 桌面 ===== */
@media (min-width: 1024px) {
  .page-about .about-layout {
    grid-template-columns: 240px minmax(0, 1fr);
    gap: 64px;
    align-items: start;
  }

  .page-about .about-index {
    position: sticky;
    top: 136px;
    padding: 24px;
  }

  .page-about .about-index__list {
    grid-template-columns: 1fr;
  }

  .page-about .about-index__note {
    display: flex;
  }

  .page-about .about-section + .about-section {
    margin-top: 80px;
  }

  .page-about .about-positioning__grid {
    grid-template-columns: minmax(0, 1fr) 300px;
  }

  .page-about .about-positioning__aside {
    grid-template-columns: 1fr;
  }

  .page-about .about-end-links {
    font-size: 15px;
  }
}