.page-about {
  font-family: var(--font-sans);
  color: var(--graphite);
  background: var(--mist);
}

/* ---------- 首屏 ---------- */
.page-about .hero {
  background: var(--mist);
  border-bottom: 1px solid var(--line);
  padding: clamp(30px, 5vw, 60px) 0 clamp(38px, 6vw, 72px);
}

.page-about .hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 3.5vw, 44px);
}

.page-about .hero__eyebrow {
  margin: 0 0 14px;
  padding-left: 16px;
  position: relative;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--red);
  text-transform: uppercase;
}

.page-about .hero__eyebrow::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: 9px;
  height: 9px;
  transform: translateY(-50%);
  background: var(--yellow);
  border: 2px solid var(--red);
  box-sizing: border-box;
}

.page-about .hero h1 {
  margin: 0 0 18px;
  max-width: 20ch;
  font-size: clamp(27px, 4.4vw, 46px);
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -.01em;
  color: var(--ink);
}

.page-about .hero__text {
  margin: 0 0 26px;
  max-width: 44ch;
  font-size: 16px;
  line-height: 1.8;
  color: var(--graphite);
}

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

.page-about .hero__panel {
  background: rgba(255, 255, 255, .68);
  border: 1px solid var(--line);
  border-top: 3px solid var(--red);
  border-radius: 2px;
  padding: 20px 22px 6px;
  box-shadow: 0 12px 32px rgba(16, 20, 24, .07);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
}

.page-about .hero__panel-title {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--red);
  text-transform: uppercase;
}

.page-about .hero__row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 14px;
  padding: 13px 0;
  border-bottom: 1px dashed var(--line);
}

.page-about .hero__row:last-child {
  border-bottom: 0;
}

.page-about .hero__k {
  font-size: 13px;
  line-height: 1.5;
  color: var(--graphite);
}

.page-about .hero__v {
  flex: none;
  font-family: var(--font-mono);
  font-size: 20px;
  font-weight: 700;
  color: var(--ink);
  letter-spacing: -.01em;
}

@media (min-width: 920px) {
  .page-about .hero__grid {
    grid-template-columns: minmax(0, 1.32fr) minmax(300px, .86fr);
    align-items: start;
  }
}

/* ---------- 通用分节 ---------- */
.page-about .sec {
  padding: clamp(40px, 6vw, 82px) 0;
}

.page-about .sec--alt {
  background: var(--white);
}

.page-about .band {
  height: 8px;
  background: var(--red);
}

.page-about .sec__head {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 8px;
  margin-bottom: clamp(22px, 3vw, 40px);
}

.page-about .sec__no {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(38px, 6vw, 62px);
  font-weight: 300;
  line-height: .9;
  letter-spacing: -.05em;
  color: var(--red);
}

.page-about .sec__title {
  margin: 0 0 10px;
  font-size: clamp(22px, 3vw, 32px);
  font-weight: 800;
  line-height: 1.3;
  color: var(--ink);
}

.page-about .sec__lead {
  margin: 0;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--graphite);
}

@media (min-width: 760px) {
  .page-about .sec__head {
    grid-template-columns: 118px minmax(0, 1fr);
    gap: 0 26px;
    align-items: start;
  }
}

/* ---------- 01 起源 ---------- */
.page-about .origin-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--gap);
}

.page-about .origin-card {
  position: relative;
  background: rgba(255, 255, 255, .74);
  border: 1px solid var(--line);
  border-left: 3px solid var(--red);
  border-radius: 2px;
  padding: 24px 22px 26px;
  box-shadow: 0 10px 26px rgba(16, 20, 24, .05);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
  transition: transform .24s var(--ease), box-shadow .24s var(--ease), background-color .24s var(--ease);
}

.page-about .origin-card:hover {
  transform: translateY(-5px);
  background: var(--white);
  box-shadow: 0 18px 38px rgba(16, 20, 24, .11);
}

.page-about .origin-card__tag {
  display: inline-block;
  margin: 0 0 12px;
  padding: 3px 10px;
  background: var(--yellow-pale);
  color: var(--ink);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .06em;
  border-radius: 2px;
}

.page-about .origin-card__title {
  margin: 0 0 10px;
  font-size: 19px;
  line-height: 1.42;
  color: var(--ink);
}

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

@media (min-width: 760px) {
  .page-about .origin-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

/* ---------- 02 时间轴 ---------- */
.page-about .sec--timeline {
  position: relative;
  overflow: hidden;
  background: var(--mist);
}

.page-about .tl__backdrop {
  position: absolute;
  top: 0;
  right: 0;
  width: min(42%, 460px);
  height: auto;
  max-width: 100%;
  object-fit: cover;
  opacity: .1;
  pointer-events: none;
  z-index: 0;
}

.page-about .sec--timeline .shell {
  position: relative;
  z-index: 1;
}

.page-about .tl-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0 0 clamp(22px, 3vw, 36px);
}

.page-about .tl-nav__item {
  display: inline-block;
  padding: 6px 14px;
  border: 1px solid var(--line);
  border-radius: 2px;
  background: var(--white);
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--ink);
  text-decoration: none;
  transition: background-color .22s var(--ease), color .22s var(--ease), border-color .22s var(--ease);
}

.page-about .tl-nav__item:hover,
.page-about .tl-nav__item:focus-visible {
  background: var(--red);
  border-color: var(--red);
  color: var(--white);
}

.page-about .tl {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .tl__item {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 6px;
  margin: 0 0 34px;
  padding-left: 22px;
  border-left: 2px solid var(--line);
  scroll-margin-top: 140px;
}

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

.page-about .tl__item::before {
  content: "";
  position: absolute;
  left: -8px;
  top: 8px;
  width: 14px;
  height: 14px;
  box-sizing: border-box;
  border-radius: 50%;
  background: var(--yellow);
  border: 3px solid var(--red);
}

.page-about .tl__year {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(46px, 9vw, 96px);
  font-weight: 800;
  line-height: .86;
  letter-spacing: -.055em;
  color: var(--ink);
}

.page-about .tl__title {
  margin: 0 0 10px;
  font-size: 20px;
  line-height: 1.4;
  color: var(--ink);
}

.page-about .tl__text {
  margin: 0 0 14px;
  max-width: 56ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--graphite);
}

.page-about .tl__more summary,
.page-about .tcard__more summary {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  cursor: pointer;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .02em;
  color: var(--blue-deep);
  list-style: none;
}

.page-about .tl__more summary::-webkit-details-marker,
.page-about .tcard__more summary::-webkit-details-marker {
  display: none;
}

.page-about .tl__more summary::before,
.page-about .tcard__more summary::before {
  content: "＋";
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--red);
}

.page-about .tl__more[open] summary::before,
.page-about .tcard__more[open] summary::before {
  content: "－";
}

.page-about .tl__more ul,
.page-about .tcard__more ul {
  margin: 12px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .tl__more li,
.page-about .tcard__more li {
  position: relative;
  margin: 0 0 9px;
  padding-left: 17px;
  font-size: 14px;
  line-height: 1.75;
  color: var(--graphite);
}

.page-about .tl__more li::before,
.page-about .tcard__more li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .62em;
  width: 7px;
  height: 7px;
  background: var(--yellow);
}

@media (min-width: 840px) {
  .page-about .tl__item {
    grid-template-columns: 210px minmax(0, 1fr);
    gap: 0 30px;
    margin-bottom: 48px;
    padding-left: 26px;
  }

  .page-about .tl__year {
    padding-top: 2px;
  }
}

/* ---------- 03 团队 ---------- */
.page-about .team-figure {
  margin: 0 0 clamp(24px, 3vw, 38px);
}

.page-about .team-list {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--gap);
}

.page-about .tcard {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 24px 22px 26px;
  background: rgba(255, 255, 255, .76);
  border: 1px solid var(--line);
  border-top: 3px solid var(--red);
  border-radius: 2px;
  box-shadow: 0 10px 26px rgba(16, 20, 24, .05);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
  transition: transform .24s var(--ease), box-shadow .24s var(--ease), background-color .24s var(--ease);
}

.page-about .tcard:hover {
  transform: translateY(-5px);
  background: var(--white);
  box-shadow: 0 18px 40px rgba(16, 20, 24, .12);
}

.page-about .tcard__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 44px;
  font-weight: 800;
  line-height: .95;
  letter-spacing: -.04em;
  color: var(--red);
}

.page-about .tcard__title {
  margin: 0;
  font-size: 18px;
  line-height: 1.4;
  color: var(--ink);
}

.page-about .tcard__text {
  margin: 0 0 4px;
  font-size: 14px;
  line-height: 1.8;
  color: var(--graphite);
}

.page-about .tcard__more {
  margin-top: auto;
  padding-top: 12px;
  border-top: 1px dashed var(--line);
}

@media (min-width: 780px) {
  .page-about .team-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

/* ---------- 04 数据来源 ---------- */
.page-about .source-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 4vw, 48px);
}

.page-about .steps {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .steps__item {
  position: relative;
  padding: 0 0 0 58px;
  margin: 0 0 30px;
}

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

.page-about .steps__item:not(:last-child)::after {
  content: "";
  position: absolute;
  left: 18px;
  top: 46px;
  bottom: -8px;
  width: 2px;
  background: var(--line);
}

.page-about .steps__no {
  position: absolute;
  left: 0;
  top: 0;
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  background: var(--ink);
  color: var(--yellow);
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  border-radius: 2px;
}

.page-about .steps__title {
  margin: 4px 0 8px;
  font-size: 17px;
  line-height: 1.4;
  color: var(--ink);
}

.page-about .steps__text {
  margin: 0;
  max-width: 52ch;
  font-size: 14px;
  line-height: 1.8;
  color: var(--graphite);
}

.page-about .source-figure {
  margin: 0;
}

@media (min-width: 900px) {
  .page-about .source-grid {
    grid-template-columns: minmax(0, 1.06fr) minmax(0, .94fr);
    align-items: start;
  }

  .page-about .source-figure {
    position: sticky;
    top: 120px;
  }
}

/* ---------- 05 合作与认证 ---------- */
.page-about .partner-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--gap);
}

.page-about .partner-card {
  padding: 26px 24px 28px;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 2px;
}

.page-about .partner-card__v {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 46px;
  font-weight: 800;
  line-height: 1;
  letter-spacing: -.04em;
  color: var(--red);
}

.page-about .partner-card__t {
  margin: 0 0 10px;
  font-size: 18px;
  line-height: 1.4;
  color: var(--ink);
}

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

.page-about .partner-card--seal {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  background: var(--yellow-pale);
  border-color: var(--yellow);
}

.page-about .seal {
  display: grid;
  place-items: center;
  width: 108px;
  height: 108px;
  border-radius: 50%;
  border: 2px solid var(--red);
  background: rgba(255, 255, 255, .72);
  color: var(--red-deep);
  text-align: center;
  line-height: 1.2;
}

.page-about .seal__top,
.page-about .seal__bot {
  display: block;
  font-size: 10px;
  letter-spacing: .12em;
}

.page-about .seal__mid {
  display: block;
  font-family: var(--font-mono);
  font-size: 32px;
  font-weight: 800;
  line-height: 1.1;
}

@media (min-width: 780px) {
  .page-about .partner-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .partner-card--seal {
    grid-template-columns: 108px minmax(0, 1fr);
    align-items: center;
    gap: 16px 20px;
  }

  .page-about .partner-card--seal .partner-card__t,
  .page-about .partner-card--seal .partner-card__d {
    grid-column: 2;
  }
}

/* ---------- 06 存档墙 ---------- */
.page-about .awall {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: 2px;
  overflow: hidden;
}

.page-about .awall__cell {
  background: var(--mist);
  padding: 22px 20px;
}

.page-about .awall__v {
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-mono);
  font-size: clamp(26px, 4vw, 36px);
  font-weight: 700;
  line-height: 1.05;
  letter-spacing: -.03em;
  color: var(--ink);
}

.page-about .awall__v--red {
  color: var(--red);
}

.page-about .awall__v--yellow {
  color: var(--yellow-deep);
}

.page-about .awall__k {
  display: block;
  font-size: 13px;
  line-height: 1.6;
  color: var(--graphite);
}

.page-about .archive-foot {
  display: grid;
  gap: 20px;
  margin-top: clamp(24px, 3vw, 38px);
  padding-top: clamp(22px, 3vw, 32px);
  border-top: 2px solid var(--red);
}

.page-about .archive-foot__text {
  margin: 0;
  max-width: 64ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--graphite);
}

.page-about .archive-foot__text a {
  color: var(--blue-deep);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .archive-foot__text a:hover {
  color: var(--red);
}

.page-about .archive-foot__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

@media (min-width: 640px) {
  .page-about .awall {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .page-about .awall {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .archive-foot {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: end;
    gap: 32px;
  }
}

/* ---------- 响应式收口 ---------- */
@media (max-width: 480px) {
  .page-about .hero__row {
    flex-direction: column;
    align-items: flex-start;
    gap: 4px;
  }

  .page-about .hero__v {
    font-size: 18px;
  }

  .page-about .partner-card__v {
    font-size: 38px;
  }

  .page-about .tcard__num {
    font-size: 38px;
  }
}