.page-about {
  --about-rail: 258px;
  --about-gap: clamp(32px, 5vw, 72px);
  background: var(--qm-void);
  color: var(--qm-paper);
}

.page-about .about-crumb-sep {
  color: var(--qm-mist);
  opacity: .6;
  margin-inline: 8px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding-block: clamp(32px, 6vw, 64px) clamp(40px, 6vw, 80px);
  background:
    radial-gradient(110% 90% at 92% -10%, rgba(255, 90, 54, .20), transparent 58%),
    radial-gradient(80% 70% at -8% 108%, rgba(54, 242, 200, .13), transparent 62%),
    var(--qm-void);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -140px;
  right: -120px;
  width: 420px;
  height: 420px;
  border: 1px solid var(--qm-line-mint);
  border-radius: 50%;
  opacity: .5;
  pointer-events: none;
}

.page-about .about-hero__inner {
  position: relative;
  display: grid;
  gap: clamp(32px, 5vw, 56px);
  align-items: end;
}

.page-about .about-hero__title {
  margin: 14px 0 0;
  font-family: var(--qm-serif);
  font-weight: 900;
  font-size: clamp(32px, 6.6vw, 66px);
  line-height: 1.1;
  letter-spacing: -0.03em;
  color: var(--qm-paper);
}

.page-about .about-hero__accent {
  color: var(--qm-mint);
  display: inline-block;
  padding-bottom: 6px;
  background-image: linear-gradient(90deg, var(--qm-flare), transparent 78%);
  background-repeat: no-repeat;
  background-size: 100% 3px;
  background-position: 0 100%;
}

.page-about .about-hero__lede {
  margin-top: 22px;
  max-width: 62ch;
  color: var(--qm-mist);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 30px;
}

.page-about .about-hero__figures {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--qm-line);
  border: 1px solid var(--qm-line);
  clip-path: polygon(var(--qm-cut) 0, 100% 0, 100% calc(100% - var(--qm-cut)), calc(100% - var(--qm-cut)) 100%, 0 100%, 0 var(--qm-cut));
  overflow: hidden;
}

.page-about .about-fig {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 22px 18px;
  background: rgba(13, 27, 47, .92);
}

.page-about .about-fig__num {
  font-size: clamp(22px, 3.4vw, 30px);
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--qm-flare);
}

.page-about .about-fig:nth-child(2) .about-fig__num,
.page-about .about-fig:nth-child(3) .about-fig__num {
  color: var(--qm-mint);
}

.page-about .about-fig__label {
  font-size: 13px;
  line-height: 1.6;
  color: var(--qm-mist);
}

/* ---------- 正文两栏 ---------- */
.page-about .about-body {
  padding-block: clamp(40px, 6vw, 72px) clamp(56px, 8vw, 104px);
  display: grid;
  gap: clamp(28px, 4vw, 48px);
}

.page-about .about-toc {
  align-self: start;
  border-top: 2px solid var(--qm-flare);
  padding-top: 16px;
}

.page-about .about-toc__label {
  font-size: 12px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--qm-mist);
  margin: 0 0 14px;
}

.page-about .about-toc__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 2px;
}

.page-about .about-toc__link {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 11px 12px 11px 10px;
  color: var(--qm-mist);
  text-decoration: none;
  border-left: 2px solid transparent;
  font-size: 14px;
  line-height: 1.5;
  transition: color .25s var(--qm-ease), border-color .25s var(--qm-ease), background .25s var(--qm-ease);
}

.page-about .about-toc__link:hover,
.page-about .about-toc__link:focus-visible {
  color: var(--qm-paper);
  border-left-color: var(--qm-mint);
  background: rgba(54, 242, 200, .07);
}

.page-about .about-toc__num {
  font-size: 11px;
  color: var(--qm-flare);
  flex: 0 0 auto;
}

.page-about .about-toc__foot {
  margin-top: 22px;
  padding: 16px;
  background: var(--qm-night);
  border-left: 2px solid var(--qm-violet);
}

.page-about .about-toc__foot-text {
  margin: 0 0 8px;
  font-size: 13px;
  color: var(--qm-mist);
}

.page-about .about-toc__cta {
  color: var(--qm-mint);
  font-size: 14px;
  font-weight: 700;
  text-decoration: none;
  border-bottom: 1px solid var(--qm-line-mint);
  padding-bottom: 2px;
}

.page-about .about-toc__cta:hover {
  color: var(--qm-flare);
  border-bottom-color: var(--qm-flare);
}

/* ---------- 章节通用 ---------- */
.page-about .about-chapter {
  padding-block: clamp(30px, 4.4vw, 56px);
  border-top: 1px solid var(--qm-line-soft);
}

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

.page-about .about-chapter__title {
  margin: 12px 0 0;
  font-family: var(--qm-sans);
  font-weight: 900;
  font-size: clamp(25px, 4vw, 40px);
  line-height: 1.24;
  letter-spacing: -0.02em;
  color: var(--qm-paper);
}

.page-about .about-chapter__lede {
  margin-top: 16px;
  max-width: 60ch;
  color: var(--qm-mist);
}

.page-about .about-chapter__text {
  margin-top: 22px;
  max-width: 64ch;
}

.page-about .about-chapter__text p {
  margin: 0 0 1.15em;
}

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

/* ---------- 定位标签条 ---------- */
.page-about .about-origin__strip {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 26px;
}

/* ---------- 图片位 ---------- */
.page-about .about-media {
  margin: clamp(24px, 3.4vw, 36px) 0 0;
}

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

.page-about .about-media--team {
  margin-top: 30px;
}

.page-about .about-media--cert {
  margin-top: 34px;
}

/* ---------- 时间线 ---------- */
.page-about .about-timeline {
  list-style: none;
  margin: clamp(26px, 3.6vw, 40px) 0 0;
  padding: 0 0 0 26px;
  position: relative;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 10px;
  bottom: 10px;
  width: 2px;
  background: linear-gradient(180deg, var(--qm-mint) 0%, var(--qm-flare) 52%, var(--qm-violet) 100%);
  opacity: .6;
}

.page-about .about-timeline__item {
  position: relative;
  padding-bottom: 10px;
}

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: -26px;
  top: 16px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--qm-void);
  border: 2px solid var(--qm-mint);
  box-shadow: 0 0 0 4px rgba(54, 242, 200, .12);
}

.page-about .about-timeline__item:nth-child(3n+2)::before {
  border-color: var(--qm-flare);
  box-shadow: 0 0 0 4px rgba(255, 90, 54, .14);
}

.page-about .about-timeline__item:nth-child(3n)::before {
  border-color: var(--qm-violet);
  box-shadow: 0 0 0 4px rgba(138, 108, 255, .14);
}

.page-about .about-node {
  background: transparent;
  border-left: 1px solid transparent;
  transition: background .3s var(--qm-ease), border-color .3s var(--qm-ease);
}

.page-about .about-node[open] {
  background: rgba(13, 27, 47, .78);
  border-left-color: var(--qm-line-mint);
}

.page-about .about-node__summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px 16px;
  padding: 12px 14px;
  cursor: pointer;
  list-style: none;
  transition: color .25s var(--qm-ease);
}

.page-about .about-node__summary::-webkit-details-marker {
  display: none;
}

.page-about .about-node__summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--qm-mono);
  font-size: 16px;
  color: var(--qm-mint);
  line-height: 1;
}

.page-about .about-node[open] .about-node__summary::after {
  content: "–";
  color: var(--qm-flare);
}

.page-about .about-node__summary:hover .about-node__title {
  color: var(--qm-mint);
}

.page-about .about-node__year {
  font-size: 13px;
  letter-spacing: .08em;
  color: var(--qm-flare);
  flex: 0 0 auto;
}

.page-about .about-node__title {
  font-size: clamp(15px, 2.2vw, 17px);
  font-weight: 700;
  color: var(--qm-paper);
  transition: color .25s var(--qm-ease);
}

.page-about .about-node__body {
  padding: 4px 14px 18px;
}

.page-about .about-node__body p {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--qm-mist);
  max-width: 62ch;
}

/* ---------- 团队矩阵 ---------- */
.page-about .about-matrix {
  display: grid;
  gap: 1px;
  margin-top: 26px;
  background: var(--qm-line);
  border-block: 1px solid var(--qm-line);
}

.page-about .about-matrix__cell {
  display: grid;
  gap: 6px;
  padding: 22px 18px;
  background: var(--qm-night);
}

.page-about .about-matrix__num {
  font-size: 30px;
  font-weight: 700;
  color: var(--qm-mint);
  letter-spacing: -0.02em;
  line-height: 1;
}

.page-about .about-matrix__cell:nth-child(2) .about-matrix__num {
  color: var(--qm-flare);
}

.page-about .about-matrix__cell:nth-child(3) .about-matrix__num {
  color: var(--qm-violet);
}

.page-about .about-matrix__name {
  font-size: 15px;
  font-weight: 700;
  color: var(--qm-paper);
}

.page-about .about-matrix__desc {
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--qm-mist);
}

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

.page-about .about-cadence__title {
  margin: 0 0 12px;
  font-size: 13px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--qm-mist);
  font-weight: 700;
}

.page-about .about-cadence__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--qm-line-soft);
}

.page-about .about-cadence__list li {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 18px;
  align-items: baseline;
  padding: 13px 14px;
  background: var(--qm-void);
  border-left: 2px solid var(--qm-canyon);
  transition: border-color .25s var(--qm-ease);
}

.page-about .about-cadence__list li:hover {
  border-left-color: var(--qm-mint);
}

.page-about .about-cadence__k {
  font-size: 12.5px;
  letter-spacing: .06em;
  color: var(--qm-flare);
  flex: 0 0 auto;
  min-width: 96px;
}

.page-about .about-cadence__v {
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--qm-paper);
}

/* ---------- 认证 ---------- */
.page-about .about-certify {
  display: grid;
  gap: 26px;
  margin-top: 26px;
  align-items: start;
}

.page-about .about-cert {
  display: grid;
  gap: 12px;
}

.page-about .about-cert__mark {
  position: relative;
  display: grid;
  place-content: center;
  justify-items: center;
  gap: 4px;
  aspect-ratio: 1 / 1;
  max-width: 190px;
  padding: 18px;
  background:
    linear-gradient(135deg, rgba(54, 242, 200, .12), transparent 55%),
    var(--qm-night);
  border: 1px solid var(--qm-line-mint);
  clip-path: polygon(0 0, calc(100% - 22px) 0, 100% 22px, 100% 100%, 22px 100%, 0 calc(100% - 22px));
  transition: transform .3s var(--qm-ease), box-shadow .3s var(--qm-ease);
  outline: none;
}

.page-about .about-cert__mark:hover,
.page-about .about-cert__mark:focus-visible {
  transform: translateY(-3px);
  box-shadow: 0 14px 34px rgba(54, 242, 200, .16);
}

.page-about .about-cert__frame {
  position: absolute;
  inset: 9px;
  border: 1px dashed rgba(255, 90, 54, .38);
  pointer-events: none;
}

.page-about .about-cert__v {
  font-size: 40px;
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--qm-mint);
  line-height: 1;
}

.page-about .about-cert__sub {
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--qm-mist);
}

.page-about .about-cert__tip {
  margin: 0;
  font-size: 13px;
  line-height: 1.7;
  color: var(--qm-mist);
  max-width: 30ch;
  opacity: .85;
  transition: opacity .25s var(--qm-ease), color .25s var(--qm-ease);
}

.page-about .about-cert:hover .about-cert__tip {
  opacity: 1;
  color: var(--qm-paper);
}

.page-about .about-certify__text p {
  margin: 0 0 1.15em;
  font-size: 16px;
  line-height: 1.85;
  color: var(--qm-mist);
  max-width: 62ch;
}

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

/* ---------- 内部链接块 ---------- */
.page-about .about-links {
  display: grid;
  gap: 1px;
  margin-top: 26px;
  background: var(--qm-line);
  border-block: 1px solid var(--qm-line);
}

.page-about .about-links__item {
  display: grid;
  gap: 6px;
  padding: 20px 18px;
  background: var(--qm-night);
  text-decoration: none;
  border-left: 2px solid transparent;
  transition: border-color .25s var(--qm-ease), background .25s var(--qm-ease);
}

.page-about .about-links__item:hover,
.page-about .about-links__item:focus-visible {
  border-left-color: var(--qm-flare);
  background: var(--qm-canyon);
}

.page-about .about-links__k {
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--qm-mint);
}

.page-about .about-links__v {
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--qm-paper);
}

/* ---------- 场景 ---------- */
.page-about .about-scenes {
  display: grid;
  gap: 22px;
  margin-top: 28px;
}

.page-about .about-scene__title {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 700;
  color: var(--qm-paper);
  padding-left: 12px;
  border-left: 3px solid var(--qm-mint);
  line-height: 1.45;
}

.page-about .about-scene:nth-child(2) .about-scene__title { border-left-color: var(--qm-flare); }
.page-about .about-scene:nth-child(3) .about-scene__title { border-left-color: var(--qm-violet); }
.page-about .about-scene:nth-child(4) .about-scene__title { border-left-color: var(--qm-ember); }

.page-about .about-scene__text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--qm-mist);
  padding-left: 15px;
}

/* ---------- 规模数字 ---------- */
.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: 34px;
  background: var(--qm-line);
  border: 1px solid var(--qm-line);
}

.page-about .about-stat {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 20px 16px;
  background: rgba(6, 16, 31, .96);
}

.page-about .about-stat__n {
  font-size: clamp(22px, 3.6vw, 30px);
  font-weight: 700;
  color: var(--qm-flare);
  letter-spacing: -0.02em;
  line-height: 1;
}

.page-about .about-stat:nth-child(even) .about-stat__n {
  color: var(--qm-mint);
}

.page-about .about-stat__l {
  font-size: 12.5px;
  color: var(--qm-mist);
}

/* ---------- 联系 ---------- */
.page-about .about-contact {
  margin-top: 34px;
  padding: clamp(22px, 3.6vw, 34px);
  background:
    linear-gradient(115deg, rgba(255, 90, 54, .14), transparent 58%),
    var(--qm-canyon);
  clip-path: polygon(var(--qm-cut) 0, 100% 0, 100% 100%, 0 100%, 0 var(--qm-cut));
  display: grid;
  gap: 22px;
  align-items: center;
}

.page-about .about-contact__title {
  margin: 0 0 8px;
  font-size: clamp(19px, 2.8vw, 24px);
  font-weight: 900;
  line-height: 1.35;
  color: var(--qm-paper);
}

.page-about .about-contact__text p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--qm-mist);
  max-width: 52ch;
}

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

/* ---------- 断点 ---------- */
@media (min-width: 720px) {
  .page-about .about-hero__figures {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

  .page-about .about-scenes {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 26px 34px;
  }

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

  .page-about .about-certify {
    grid-template-columns: 190px minmax(0, 1fr);
    gap: 32px;
  }

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

  .page-about .about-contact {
    grid-template-columns: minmax(0, 1fr) auto;
    gap: 30px;
  }
}

@media (min-width: 960px) {
  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 1.35fr) minmax(300px, .8fr);
    gap: 56px;
  }

  .page-about .about-body {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: var(--about-gap);
    align-items: start;
  }

  .page-about .about-toc {
    position: sticky;
    top: calc(var(--qm-header-h) + 26px);
    max-height: calc(100vh - var(--qm-header-h) - 52px);
    overflow-y: auto;
  }

  .page-about .about-chapter__text {
    max-width: 66ch;
  }

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

  .page-about .about-media--cert {
    max-width: 680px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-toc__link,
  .page-about .about-cert__mark,
  .page-about .about-cert__tip,
  .page-about .about-node__title,
  .page-about .about-node,
  .page-about .about-links__item,
  .page-about .about-cadence__list li {
    transition: none;
  }

  .page-about .about-cert__mark:hover,
  .page-about .about-cert__mark:focus-visible {
    transform: none;
  }
}