.page-about {
  --about-hair: rgba(20, 26, 34, 0.12);
  --about-ink-soft: #59657A;
  background: var(--bb-mist);
  color: var(--bb-ink);
  position: relative;
  overflow-x: hidden;
}

.page-about .mono {
  font-family: var(--font-mono);
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumb {
  padding-top: 28px;
  padding-bottom: 4px;
}
.page-about .breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 0;
  font-family: var(--font-narrow);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--about-ink-soft);
}
.page-about .breadcrumb li + li::before {
  content: "/";
  margin-right: 8px;
  color: var(--bb-silver);
}
.page-about .breadcrumb a {
  color: var(--bb-blue);
  text-decoration: none;
}
.page-about .breadcrumb a:hover {
  text-decoration: underline;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-top: 20px;
  border-bottom: 1px solid var(--bb-silver);
}
.page-about .about-hero__grid {
  display: grid;
  gap: 28px;
  padding-bottom: 36px;
}
.page-about .about-hero__eyebrow {
  color: var(--bb-blue);
  margin: 0 0 12px;
}
.page-about .about-hero__title {
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 30px;
  line-height: 1.28;
  letter-spacing: -0.01em;
  margin: 0;
  max-width: 15em;
}
.page-about .about-hero__aside p {
  margin: 0 0 14px;
  font-size: 16px;
  line-height: 1.85;
  color: var(--about-ink-soft);
  max-width: 34em;
}
.page-about .about-hero__aside p:first-child {
  color: var(--bb-ink);
}
.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 20px;
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: 56px;
    align-items: end;
    padding-bottom: 52px;
  }
}
@media (min-width: 1080px) {
  .page-about .about-hero__title {
    font-size: 46px;
    line-height: 1.22;
  }
}

/* ---------- 数据条 ---------- */
.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--bb-silver);
  border-top: 1px solid var(--bb-silver);
  border-bottom: 1px solid var(--bb-silver);
}
.page-about .about-stat {
  background: var(--bb-mist);
  padding: 20px 18px 22px;
}
.page-about .about-stat__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 30px;
  font-weight: 600;
  line-height: 1;
  color: var(--bb-navy);
}
.page-about .about-stat__label {
  display: block;
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--about-ink-soft);
}
@media (min-width: 780px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .about-stat {
    padding: 26px 22px 28px;
  }
  .page-about .about-stat__num {
    font-size: 36px;
  }
}

/* ---------- 导读 ---------- */
.page-about .anchor-index {
  padding-top: 34px;
  padding-bottom: 34px;
}
.page-about .anchor-index__title {
  margin: 0 0 16px;
  color: var(--bb-blue);
}
.page-about .about-index-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 0;
}
.page-about .about-index-list a {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 8px 14px;
  border: 1px solid var(--bb-silver);
  background: #fff;
  color: var(--bb-ink);
  text-decoration: none;
  font-size: 14px;
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease), background var(--dur) var(--ease);
}
.page-about .about-index-list a:hover,
.page-about .about-index-list a:focus-visible {
  border-color: var(--bb-blue);
  color: var(--bb-blue);
  background: var(--bb-pale);
}
.page-about .about-index-list .mono {
  font-size: 12px;
  color: var(--bb-blue);
}

/* ---------- 章节通用 ---------- */
.page-about .about-sec {
  padding: 52px 0;
}
.page-about .about-sec__head {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--bb-silver);
  margin-bottom: 28px;
}
.page-about .about-sec__no {
  font-size: 14px;
  color: var(--bb-blue);
  letter-spacing: 0.06em;
  flex: none;
}
.page-about .about-sec__title {
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 23px;
  line-height: 1.34;
  margin: 0;
}
.page-about .about-lead {
  margin: 0 0 26px;
  font-size: 16px;
  line-height: 1.85;
  color: var(--about-ink-soft);
  max-width: 38em;
}
@media (min-width: 900px) {
  .page-about .about-sec {
    padding: 78px 0;
  }
  .page-about .about-sec__title {
    font-size: 30px;
  }
}

/* ---------- 01 起源 ---------- */
.page-about .about-origin__fig {
  margin: 0 0 30px;
}
.page-about .about-origin__fig img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}
.page-about .about-origin__grid {
  display: grid;
  gap: 28px;
}
.page-about .about-origin__body p {
  margin: 0 0 18px;
  font-size: 16px;
  line-height: 1.85;
  max-width: 36em;
}
.page-about .about-origin__body p:last-child {
  margin-bottom: 0;
}
.page-about .about-origin__side {
  border-left: 3px solid var(--bb-blue);
  padding: 4px 0 4px 18px;
}
.page-about .about-origin__side-title {
  margin: 0 0 14px;
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--bb-navy);
}
.page-about .about-origin__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
}
.page-about .about-origin__list li {
  display: flex;
  gap: 10px;
  align-items: baseline;
  font-size: 14px;
  line-height: 1.7;
  color: var(--about-ink-soft);
  border-bottom: 1px dashed var(--bb-silver);
  padding-bottom: 12px;
}
.page-about .about-origin__list li:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}
.page-about .about-origin__list .mono {
  flex: none;
  font-size: 12px;
  color: var(--bb-amber);
  font-weight: 600;
}
@media (min-width: 900px) {
  .page-about .about-origin__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: 56px;
    align-items: start;
  }
  .page-about .about-origin__side {
    margin-top: 44px;
    padding-left: 22px;
  }
}

/* ---------- 02 双线 ---------- */
.page-about .about-filter {
  margin-bottom: 22px;
}
.page-about .about-lines {
  display: grid;
  gap: 18px;
}
.page-about .about-line {
  padding: 26px 22px 28px;
  clip-path: polygon(0 0, calc(100% - 26px) 0, 100% 26px, 100% 100%, 0 100%);
}
.page-about .about-line--home {
  background: var(--bb-silver);
  color: var(--bb-ink);
}
.page-about .about-line--pc {
  background: var(--bb-black);
  color: #E6EBF2;
}
.page-about .about-line__tag {
  margin: 0 0 12px;
  font-size: 12px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  opacity: 0.72;
}
.page-about .about-line__title {
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 20px;
  line-height: 1.4;
  margin: 0 0 18px;
}
.page-about .about-line__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
}
.page-about .about-line__list li {
  font-size: 15px;
  line-height: 1.8;
  padding-left: 16px;
  position: relative;
}
.page-about .about-line__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 8px;
  height: 2px;
  background: var(--bb-blue);
}
.page-about .about-line--pc .about-line__list li::before {
  background: var(--bb-amber);
}
.page-about .about-line__list strong {
  font-weight: 600;
}
@media (min-width: 860px) {
  .page-about .about-lines {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 26px;
    align-items: start;
  }
  .page-about .about-line--pc {
    margin-top: 44px;
  }
}

/* ---------- 03 团队 ---------- */
.page-about .about-sec--team {
  background: var(--bb-pale);
}
.page-about .about-ring {
  display: grid;
  gap: 30px;
  align-items: center;
}
.page-about .about-ring__figure {
  margin: 0;
}
.page-about .about-ring__svg {
  display: block;
  width: 100%;
  max-width: 320px;
  height: auto;
  margin: 0 auto;
}
.page-about .about-ring__guide {
  fill: none;
  stroke: var(--bb-silver);
  stroke-width: 1;
  stroke-dasharray: 3 7;
}
.page-about .about-ring__dot {
  fill: var(--bb-blue);
}
.page-about .about-ring__dot--ext {
  fill: var(--bb-amber);
}
.page-about .about-ring__num {
  font-family: var(--font-mono);
  font-size: 36px;
  font-weight: 600;
  fill: var(--bb-navy);
  text-anchor: middle;
}
.page-about .about-ring__unit {
  font-family: var(--font-body);
  font-size: 13px;
  fill: var(--about-ink-soft);
  text-anchor: middle;
}
.page-about .about-ring__body p {
  margin: 0 0 16px;
  font-size: 16px;
  line-height: 1.85;
  max-width: 34em;
}
.page-about .about-ring__legend {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
}
.page-about .about-ring__legend li {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  font-size: 14px;
  line-height: 1.7;
  color: var(--about-ink-soft);
}
.page-about .about-ring__key {
  flex: none;
  width: 12px;
  height: 12px;
  margin-top: 5px;
  border-radius: 50%;
}
.page-about .about-ring__key--blue {
  background: var(--bb-blue);
}
.page-about .about-ring__key--amber {
  background: var(--bb-amber);
}
.page-about .about-team__fig {
  margin: 34px 0 0;
  max-width: 420px;
}
.page-about .about-team__fig img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}
@media (min-width: 900px) {
  .page-about .about-ring {
    grid-template-columns: 320px minmax(0, 1fr);
    gap: 52px;
  }
  .page-about .about-team__fig {
    margin-top: 46px;
    margin-left: auto;
    max-width: 460px;
  }
}

/* ---------- 呼吸带 ---------- */
.page-about .about-breath__line {
  margin: 0;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 20px;
  line-height: 1.6;
  color: #ffffff;
  max-width: 26em;
}
@media (min-width: 900px) {
  .page-about .about-breath__line {
    font-size: 27px;
  }
}

/* ---------- 04 规格区间 ---------- */
.page-about .about-sec--range {
  background: var(--bb-mist);
}
.page-about .about-range {
  background: var(--bb-teal);
  color: #E5F0EB;
  padding: 32px 20px 36px;
  clip-path: polygon(0 0, calc(100% - 30px) 0, 100% 30px, 100% 100%, 0 100%);
}
.page-about .about-range__intro {
  margin: 0 0 22px;
  font-size: 16px;
  line-height: 1.85;
  color: #CFE2DA;
  max-width: 40em;
}
.page-about .about-ranges {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 22px;
}
.page-about .about-range-chip {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  padding: 6px 9px;
  border: 1px solid rgba(229, 240, 235, 0.32);
  color: #EAF4EF;
}
.page-about .about-range__note {
  margin: 0 0 26px;
  font-size: 15px;
  line-height: 1.8;
  color: #C6DCD3;
  max-width: 38em;
}
.page-about .about-certs {
  border-top: 1px solid rgba(229, 240, 235, 0.24);
}
.page-about .about-certs .collapse {
  border-bottom: 1px solid rgba(229, 240, 235, 0.24);
}
.page-about .about-certs .collapse__head {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 17px 2px;
  background: transparent;
  border: 0;
  color: #EAF4EF;
  font-family: var(--font-body);
  font-size: 16px;
  font-weight: 600;
  text-align: left;
  cursor: pointer;
}
.page-about .about-certs .collapse__head:hover {
  color: var(--bb-amber);
}
.page-about .about-certs .collapse__icon {
  position: relative;
  flex: none;
  width: 14px;
  height: 14px;
}
.page-about .about-certs .collapse__icon::before,
.page-about .about-certs .collapse__icon::after {
  content: "";
  position: absolute;
  background: var(--bb-amber);
}
.page-about .about-certs .collapse__icon::before {
  left: 0;
  top: 6px;
  width: 14px;
  height: 2px;
}
.page-about .about-certs .collapse__icon::after {
  left: 6px;
  top: 0;
  width: 2px;
  height: 14px;
  transition: opacity var(--dur) var(--ease);
}
.page-about .about-certs .collapse__head[aria-expanded="true"] .collapse__icon::after {
  opacity: 0;
}
.page-about .about-certs .collapse__body {
  padding: 0 2px 20px;
  font-size: 15px;
  line-height: 1.85;
  color: #BFD6CC;
  max-width: 40em;
}
.page-about .about-certs .collapse__body p {
  margin: 0;
}
@media (min-width: 900px) {
  .page-about .about-range {
    padding: 46px 48px 50px;
  }
}

/* ---------- 05 合作生态 ---------- */
.page-about .about-eco {
  display: grid;
  gap: 18px;
}
.page-about .about-eco__block {
  background: #ffffff;
  border: 1px solid var(--bb-silver);
  border-top: 4px solid var(--bb-navy);
  padding: 26px 22px 28px;
}
.page-about .about-eco__block--accent {
  border-top-color: var(--bb-amber);
  background: var(--bb-navy);
  color: #DCE6F5;
}
.page-about .about-eco__num {
  margin: 0 0 12px;
  font-size: 40px;
  font-weight: 600;
  line-height: 1;
  color: var(--bb-blue);
}
.page-about .about-eco__block--accent .about-eco__num {
  color: var(--bb-amber);
}
.page-about .about-eco__num span {
  font-family: var(--font-body);
  font-size: 15px;
  margin-left: 4px;
  color: var(--about-ink-soft);
}
.page-about .about-eco__block--accent .about-eco__num span {
  color: #9DB2D2;
}
.page-about .about-eco__title {
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 19px;
  line-height: 1.42;
  margin: 0 0 12px;
}
.page-about .about-eco__block p:last-child {
  margin: 0;
  font-size: 15px;
  line-height: 1.82;
  color: var(--about-ink-soft);
}
.page-about .about-eco__block--accent p:last-child {
  color: #B9C8E0;
}
@media (min-width: 880px) {
  .page-about .about-eco {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 22px;
    align-items: start;
  }
  .page-about .about-eco__block:nth-child(2) {
    margin-top: 36px;
  }
  .page-about .about-eco__block:nth-child(3) {
    margin-top: 12px;
  }
}

/* ---------- 06 时间线 ---------- */
.page-about .about-sec--timeline {
  background: var(--bb-pale);
}
.page-about .about-timeline {
  list-style: none;
  margin: 0;
  padding: 0;
}
.page-about .about-tl {
  display: grid;
  gap: 10px;
  padding: 18px 0;
  border-top: 1px solid var(--bb-silver);
}
.page-about .about-tl:last-child {
  border-bottom: 1px solid var(--bb-silver);
}
.page-about .about-tl__stage {
  margin: 0;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--bb-blue);
  padding-left: 14px;
  border-left: 3px solid var(--bb-blue);
  line-height: 1.2;
}
.page-about .about-tl__main .collapse__head {
  width: 100%;
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
  padding: 4px 0 10px;
  background: transparent;
  border: 0;
  text-align: left;
  cursor: pointer;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 18px;
  line-height: 1.45;
  color: var(--bb-ink);
}
.page-about .about-tl__main .collapse__head:hover {
  color: var(--bb-blue);
}
.page-about .about-tl__main .collapse__icon {
  position: relative;
  flex: none;
  width: 16px;
  height: 16px;
  margin-top: 5px;
}
.page-about .about-tl__main .collapse__icon::before,
.page-about .about-tl__main .collapse__icon::after {
  content: "";
  position: absolute;
  background: var(--bb-blue);
}
.page-about .about-tl__main .collapse__icon::before {
  left: 0;
  top: 7px;
  width: 16px;
  height: 2px;
}
.page-about .about-tl__main .collapse__icon::after {
  left: 7px;
  top: 0;
  width: 2px;
  height: 16px;
  transition: opacity var(--dur) var(--ease);
}
.page-about .about-tl__main .collapse__head[aria-expanded="true"] .collapse__icon::after {
  opacity: 0;
}
.page-about .about-tl__main .collapse__body {
  padding: 0 0 8px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--about-ink-soft);
  max-width: 42em;
}
.page-about .about-tl__main .collapse__body p {
  margin: 0;
}
.page-about .about-timeline__fig {
  margin: 38px 0 0;
}
.page-about .about-timeline__fig img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}
@media (min-width: 900px) {
  .page-about .about-tl {
    grid-template-columns: 150px minmax(0, 1fr);
    gap: 36px;
    padding: 22px 0;
  }
  .page-about .about-tl__stage {
    font-size: 13px;
    padding-top: 7px;
  }
}

/* ---------- 结尾行动区 ---------- */
.page-about .about-cta {
  margin-top: 44px;
  padding-top: 28px;
  border-top: 1px solid var(--bb-silver);
  display: grid;
  gap: 18px;
}
.page-about .about-cta__text {
  margin: 0;
  font-size: 16px;
  line-height: 1.8;
  color: var(--bb-ink);
  max-width: 30em;
}
.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}
@media (min-width: 900px) {
  .page-about .about-cta {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: 32px;
  }
}

/* ---------- 返回导读 ---------- */
.page-about .back-to-index {
  margin: 0;
}
</main>