.page-about {
  --about-rule: rgba(16, 21, 31, 0.14);
  --about-rule-soft: rgba(16, 21, 31, 0.07);
  --about-copper-soft: rgba(180, 134, 60, 0.16);
  --about-shadow: 0 14px 30px -22px rgba(13, 21, 51, 0.6);
  display: block;
}

.page-about .about-section {
  padding: 44px 0;
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumbs {
  margin-top: 18px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 26px;
  padding: 22px 0 6px;
}

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

.page-about .about-hero h1 {
  margin: 12px 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(28px, 6.6vw, 50px);
  line-height: 1.14;
  letter-spacing: -0.01em;
  color: var(--indigo);
}

.page-about .about-hero__lead {
  margin: 16px 0 0;
  max-width: 38em;
}

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

.page-about .about-hero__stats li {
  display: flex;
  flex-direction: column;
  gap: 5px;
  padding: 14px 16px;
  background: var(--paper-white);
}

.page-about .about-hero__stats b {
  font-family: var(--font-mono);
  font-size: 22px;
  line-height: 1.1;
  letter-spacing: 0.02em;
  color: var(--copper);
}

.page-about .about-hero__stats span {
  font-size: 13px;
  line-height: 1.5;
  color: var(--rock);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

.page-about .about-hero__media {
  margin: 0;
  border: 1px solid var(--about-rule);
  background: var(--indigo);
  box-shadow: var(--about-shadow);
}

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

/* ---------- 章节标题微调 ---------- */
.page-about .chapter {
  margin-bottom: 28px;
}

.page-about .chapter--invert .chapter__title {
  color: var(--paper);
}

.page-about .chapter--invert .chapter__note {
  color: rgba(245, 241, 232, 0.7);
}

/* ---------- 时间轴 ---------- */
.page-about .tl {
  position: relative;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .tl__item {
  position: relative;
  padding-bottom: 24px;
}

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

.page-about .tl__year {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 20px;
  line-height: 1.2;
  letter-spacing: 0.06em;
  color: var(--copper);
}

.page-about .tl__card {
  padding: 16px 18px;
  border-left: 3px solid var(--copper);
  background: var(--paper-white);
  border-top: 1px solid var(--about-rule);
  border-right: 1px solid var(--about-rule);
  border-bottom: 1px solid var(--about-rule);
}

.page-about .tl__item--current .tl__card {
  border-left-color: var(--indigo);
}

.page-about .tl__title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 17px;
  line-height: 1.45;
  color: var(--indigo);
}

.page-about .tl__card p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink);
}

/* ---------- 资质层级 ---------- */
.page-about .about-tier-visual {
  margin: 0 0 26px;
  border: 1px solid var(--about-rule);
}

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

.page-about .tiers {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
}

.page-about .tier {
  padding: 18px 18px 16px;
  background: var(--paper-white);
  border: 1px solid var(--about-rule);
  border-top: 3px solid var(--rock);
}

.page-about .tier:nth-child(2) {
  border-top-color: var(--clay);
}

.page-about .tier:nth-child(3) {
  border-top-color: var(--copper);
}

.page-about .tier:nth-child(4) {
  border-top-color: var(--indigo);
}

.page-about .tier__code {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.14em;
  color: var(--copper);
}

.page-about .tier__name {
  margin: 6px 0 12px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 19px;
  line-height: 1.3;
  color: var(--indigo);
}

.page-about .tier__kv dt {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--rock);
}

.page-about .tier__kv dd {
  margin: 2px 0 10px;
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--ink);
}

.page-about .tier__kv dd:last-child {
  margin-bottom: 0;
}

/* ---------- 编号规则 ---------- */
.page-about .num-layout {
  align-items: start;
}

.page-about .num-layout__main {
  min-width: 0;
}

.page-about .tabs {
  border: 1px solid var(--about-rule);
  background: var(--paper-white);
}

.page-about .tabs__list {
  display: flex;
  flex-wrap: wrap;
  gap: 0;
  border-bottom: 1px solid var(--about-rule);
}

.page-about .tabs__btn {
  flex: 1 1 auto;
  min-width: 96px;
  padding: 11px 14px;
  border: 0;
  border-right: 1px solid var(--about-rule);
  background: transparent;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--rock);
  cursor: pointer;
  transition: background 180ms var(--ease), color 180ms var(--ease);
}

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

.page-about .tabs__btn[aria-selected="true"] {
  background: var(--indigo);
  color: var(--copper-bright);
}

.page-about .tabs__btn:hover {
  color: var(--indigo);
}

.page-about .tabs__btn[aria-selected="true"]:hover {
  color: var(--copper-bright);
}

.page-about .tabs__panel {
  padding: 20px 18px 18px;
}

.page-about .tabs__panel[hidden] {
  display: none;
}

.page-about .codebox {
  padding: 16px 18px;
  background: var(--indigo);
  border-left: 3px solid var(--copper);
}

.page-about .codebox__label {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: rgba(245, 241, 232, 0.62);
}

.page-about .codebox__value {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(19px, 4.6vw, 28px);
  line-height: 1.2;
  letter-spacing: 0.04em;
  color: var(--copper-bright);
  overflow-wrap: anywhere;
}

.page-about .codebox__note {
  margin: 14px 0 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--rock);
}

.page-about .code-legend {
  margin: 22px 0 0;
  padding: 0;
}

.page-about .code-legend__row {
  display: grid;
  grid-template-columns: 76px minmax(0, 1fr);
  gap: 0 16px;
  padding: 12px 0;
  border-bottom: 1px solid var(--about-rule-soft);
}

.page-about .code-legend__row:first-child {
  border-top: 1px solid var(--about-rule-soft);
}

.page-about .code-legend__row dt {
  font-family: var(--font-mono);
  font-size: 15px;
  letter-spacing: 0.06em;
  color: var(--copper);
}

.page-about .code-legend__row dd {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--ink);
}

.page-about .num-layout__media {
  margin: 26px 0 0;
  border: 1px solid var(--about-rule);
  background: var(--paper-white);
}

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

/* ---------- 档案库 ---------- */
.page-about .archive-layout {
  align-items: start;
}

.page-about .archive-lead {
  margin: 0;
  font-size: 16px;
  line-height: 1.85;
  color: var(--ink);
}

.page-about .archive-lead b {
  font-family: var(--font-mono);
  font-weight: 600;
  color: var(--indigo);
}

.page-about .yearchips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .yearchips li {
  padding: 7px 12px;
  border: 1px solid var(--about-copper-soft);
  background: var(--paper-white);
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--ink);
  white-space: nowrap;
}

.page-about .archive-panel {
  margin: 24px 0 0;
  padding: 22px 20px;
  border-left: 3px solid var(--copper);
}

.page-about .archive-panel__label {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--copper-bright);
}

.page-about .archive-panel__cycle {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(22px, 5vw, 30px);
  line-height: 1.15;
  letter-spacing: 0.02em;
  color: var(--paper);
}

.page-about .archive-panel__text {
  margin: 14px 0 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: rgba(245, 241, 232, 0.86);
}

.page-about .archive-panel__meta {
  margin: 12px 0 0;
  padding-top: 12px;
  border-top: 1px solid rgba(245, 241, 232, 0.22);
  font-size: 13.5px;
  line-height: 1.7;
  color: rgba(245, 241, 232, 0.66);
}

/* ---------- 团队 ---------- */
.page-about .teams {
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--about-rule);
}

.page-about .team {
  display: grid;
  grid-template-columns: 52px minmax(0, 1fr);
  gap: 0 16px;
  padding: 22px 0;
  border-bottom: 1px solid var(--about-rule);
}

.page-about .team__idx {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border: 1px solid var(--copper);
  border-radius: 50%;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--copper);
}

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

.page-about .team__name {
  margin: 6px 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 18px;
  line-height: 1.4;
  color: var(--indigo);
}

.page-about .team__body p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink);
}

/* ---------- 协作网络 ---------- */
.page-about .eco {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  background: rgba(245, 241, 232, 0.18);
  border: 1px solid rgba(245, 241, 232, 0.18);
}

.page-about .eco__item {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 20px 18px;
  background: var(--indigo-deep);
}

.page-about .eco__item b {
  font-family: var(--font-mono);
  font-size: 30px;
  line-height: 1.05;
  letter-spacing: 0.02em;
  color: var(--copper-bright);
}

.page-about .eco__label {
  font-size: 14px;
  color: var(--paper);
}

.page-about .eco__text {
  margin: 6px 0 0;
  font-size: 13.5px;
  line-height: 1.7;
  color: rgba(245, 241, 232, 0.66);
}

.page-about .scores {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin-top: 26px;
}

.page-about .score {
  padding: 18px;
  border: 1px solid rgba(245, 241, 232, 0.28);
}

.page-about .score__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 32px;
  line-height: 1;
  color: var(--copper-bright);
}

.page-about .score__label {
  margin: 8px 0 0;
  font-size: 13.5px;
  color: rgba(245, 241, 232, 0.82);
}

.page-about .scores__note {
  grid-column: 1 / -1;
  margin: 0;
  font-size: 13px;
  line-height: 1.7;
  color: rgba(245, 241, 232, 0.6);
}

/* ---------- 行动区 ---------- */
.page-about .about-cta__box {
  padding: 30px 22px;
  background: var(--paper-white);
  border: 1px solid var(--about-rule);
  border-top: 3px solid var(--copper);
  box-shadow: var(--about-shadow);
}

.page-about .about-cta__title {
  margin: 10px 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(21px, 4.6vw, 30px);
  line-height: 1.3;
  color: var(--indigo);
}

.page-about .about-cta__text {
  margin: 14px 0 0;
  max-width: 46em;
  font-size: 15.5px;
  line-height: 1.82;
  color: var(--ink);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 22px;
}

.page-about .about-cta__meta {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
  margin: 24px 0 0;
  padding-top: 18px;
  border-top: 1px solid var(--about-rule-soft);
}

.page-about .about-cta__meta dt {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--rock);
}

.page-about .about-cta__meta dd {
  margin: 2px 0 12px;
  font-size: 15px;
  line-height: 1.6;
  color: var(--ink);
  overflow-wrap: anywhere;
}

.page-about .about-cta__meta dd:last-child {
  margin-bottom: 0;
}

/* ---------- 响应式 ---------- */
@media (min-width: 620px) {
  .page-about .about-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .tiers {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .eco {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-cta__meta {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0 24px;
  }
}

@media (min-width: 980px) {
  .page-about .about-section {
    padding: 62px 0;
  }

  .page-about .about-hero {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 48px;
    align-items: start;
    padding: 34px 0 16px;
  }

  .page-about .about-hero h1 {
    font-size: clamp(34px, 3.6vw, 50px);
  }

  .page-about .chapter {
    margin-bottom: 34px;
  }

  /* 时间轴：年份左对齐右贴，卡片在右 */
  .page-about .tl::before {
    content: "";
    position: absolute;
    top: 10px;
    bottom: 10px;
    left: 148px;
    width: 1px;
    background: linear-gradient(180deg, var(--copper) 0%, rgba(180, 134, 60, 0.12) 100%);
  }

  .page-about .tl__item {
    display: grid;
    grid-template-columns: 120px minmax(0, 1fr);
    gap: 0 56px;
    padding-bottom: 28px;
  }

  .page-about .tl__item::after {
    content: "";
    position: absolute;
    left: 142px;
    top: 7px;
    width: 13px;
    height: 13px;
    border-radius: 50%;
    background: var(--paper);
    border: 2px solid var(--copper);
  }

  .page-about .tl__item--current::after {
    background: var(--copper);
    border-color: var(--copper);
  }

  .page-about .tl__year {
    margin: 0;
    padding-top: 2px;
    text-align: right;
    font-size: 24px;
  }

  .page-about .tiers {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 16px;
  }

  .page-about .tier {
    padding: 22px 20px 20px;
  }

  .page-about .num-layout__media {
    margin-top: 0;
  }

  .page-about .archive-panel {
    margin-top: 0;
  }

  .page-about .team {
    grid-template-columns: 64px minmax(0, 1fr);
    gap: 0 22px;
    padding: 26px 0;
  }

  .page-about .eco {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-cta__box {
    padding: 44px 40px;
  }

  .page-about .about-cta__meta {
    max-width: 720px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .tabs__btn {
    transition: none;
  }
}