.page-about {
  --step-gap: 0px;
  --about-card: var(--tier);
  display: block;
  background: var(--night);
  color: var(--ink);
}

@media (min-width: 900px) {
  .page-about {
    --step-gap: 22px;
  }
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  overflow: hidden;
  background: var(--abyss);
  border-bottom: 2px solid var(--edge);
}

.page-about .about-hero__media {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.page-about .about-hero__img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.42;
}

.page-about .about-hero__glow {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(58% 66% at 80% 14%, rgba(111, 255, 233, 0.16), transparent 62%),
    radial-gradient(70% 78% at 8% 96%, rgba(255, 77, 46, 0.2), transparent 66%),
    linear-gradient(180deg, rgba(6, 16, 33, 0.4) 0%, rgba(6, 16, 33, 0.88) 60%, var(--night) 100%);
}

.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
  padding-top: 36px;
  padding-bottom: 40px;
}

@media (min-width: 760px) {
  .page-about .about-hero__inner {
    padding-top: 56px;
    padding-bottom: 64px;
  }
}

.page-about .about-hero .crumbs {
  margin-bottom: 18px;
}

.page-about .about-hero__eyebrow {
  margin: 0;
  color: var(--muted);
}

.page-about .about-hero__title {
  margin: 14px 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(32px, 8.4vw, 74px);
  line-height: 0.98;
  letter-spacing: -0.02em;
  color: var(--ink);
  max-width: 13em;
  text-shadow: 0 4px 22px rgba(6, 16, 33, 0.7);
}

.page-about .about-hero__lead {
  margin: 20px 0 0;
  max-width: 38em;
  font-size: 16px;
  line-height: 1.78;
  color: var(--muted);
}

@media (min-width: 760px) {
  .page-about .about-hero__lead {
    font-size: 17px;
  }
}

.page-about .about-hero__facts {
  display: flex;
  flex-wrap: wrap;
  gap: 14px 34px;
  margin: 28px 0 0;
  padding: 20px 0 0;
  list-style: none;
  border-top: 2px solid var(--edge);
}

.page-about .about-hero__facts li {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.page-about .about-hero__num {
  font-family: var(--font-mono);
  font-size: 24px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--ice);
  line-height: 1;
}

.page-about .about-hero__lab {
  font-size: 13px;
  color: var(--muted);
  letter-spacing: 0.02em;
}

/* ---------- 栏目索引条 ---------- */

.page-about .about-index {
  background: var(--tier);
  border-bottom: 2px solid var(--edge);
}

.page-about .about-index__inner {
  display: flex;
  gap: 8px;
  padding-top: 12px;
  padding-bottom: 12px;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-index__link {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  border: 2px solid var(--edge);
  background: var(--night);
  color: var(--ink);
  font-size: 14px;
  text-decoration: none;
  white-space: nowrap;
  transition: border-color 0.24s var(--ease), color 0.24s var(--ease), transform 0.24s var(--ease);
}

.page-about .about-index__link:hover,
.page-about .about-index__link:focus-visible {
  border-color: var(--pulse-hi);
  color: var(--pulse-hi);
  transform: translateY(-2px);
}

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

.page-about .about-index__link:hover .about-index__no,
.page-about .about-index__link:focus-visible .about-index__no {
  color: var(--pulse);
}

/* ---------- 阶梯章节 ---------- */

.page-about .about-body {
  padding-top: 20px;
  padding-bottom: 56px;
}

.page-about .about-chapter {
  position: relative;
  padding-top: 36px;
  padding-bottom: 16px;
  padding-left: calc(var(--step, 0) * var(--step-gap));
  transition: padding-left 0.3s var(--ease);
}

@media (min-width: 900px) {
  .page-about .about-chapter {
    padding-top: 56px;
  }
}

.page-about .about-chapter--last {
  padding-bottom: 24px;
}

.page-about .about-chapter__head {
  display: flex;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 12px 16px;
  padding-top: 16px;
  margin-bottom: 20px;
  border-top: 2px solid var(--edge);
}

.page-about .about-chapter__no {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.12em;
  color: var(--pulse);
  padding-top: 8px;
  flex: 0 0 auto;
}

.page-about .about-chapter__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(23px, 4.6vw, 40px);
  line-height: 1.1;
  letter-spacing: -0.01em;
  color: var(--ink);
  flex: 1 1 auto;
  min-width: 0;
}

.page-about .about-chapter__mark {
  display: none;
  margin-left: auto;
  color: var(--channel);
}

@media (min-width: 900px) {
  .page-about .about-chapter__mark {
    display: inline-block;
  }
}

.page-about .about-chapter__lead {
  margin: 0 0 22px;
  max-width: 34em;
  font-size: 16px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-chapter__text p {
  margin: 0 0 18px;
  font-size: 16px;
  line-height: 1.8;
  color: var(--ink);
}

.page-about .about-chapter__text a {
  color: var(--ice);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .about-chapter__text a:hover,
.page-about .about-chapter__text a:focus-visible {
  color: var(--pulse-hi);
}

.page-about .about-chapter__grid {
  display: grid;
  gap: 24px;
}

@media (min-width: 960px) {
  .page-about .about-chapter__grid--2 {
    grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr);
    align-items: start;
    gap: 32px;
  }
}

/* ---------- 侧栏 ---------- */

.page-about .about-aside {
  background: var(--tier);
  border: 2px solid var(--edge);
  box-shadow: var(--shadow-hard-sm);
  padding: 20px 20px 22px;
}

.page-about .about-aside__title {
  margin: 0 0 14px;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--pulse-hi);
}

.page-about .about-aside__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .about-aside__list li {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  align-items: start;
  gap: 10px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--muted);
  padding-bottom: 14px;
  border-bottom: 1px solid var(--edge);
}

.page-about .about-aside__list li:last-child {
  padding-bottom: 0;
  border-bottom: 0;
}

/* ---------- 配图 ---------- */

.page-about .about-figure {
  margin: 0 0 26px;
  border: 2px solid var(--edge);
  box-shadow: var(--shadow-hard);
  background: var(--abyss);
  overflow: hidden;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 16 / 10;
  object-fit: cover;
}

.page-about .about-figure--square img {
  aspect-ratio: 3 / 2;
}

.page-about .about-figure figcaption {
  padding: 10px 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--muted);
  background: var(--tier);
  border-top: 2px solid var(--edge);
}

/* ---------- 生产流程 ---------- */

.page-about .about-steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 16px;
}

@media (min-width: 860px) {
  .page-about .about-steps {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 20px;
  }
}

.page-about .about-step {
  position: relative;
  background: var(--about-card);
  border: 2px solid var(--edge);
  border-top: 4px solid var(--channel);
  box-shadow: var(--shadow-hard-sm);
  padding: 20px 18px 22px;
  transition: transform 0.24s var(--ease), border-color 0.24s var(--ease);
}

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

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

@media (min-width: 860px) {
  .page-about .about-step:nth-child(2) {
    margin-top: 18px;
  }
  .page-about .about-step:nth-child(3) {
    margin-top: 36px;
  }
}

.page-about .about-step__stage {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--muted);
  text-transform: uppercase;
}

.page-about .about-step__title {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 20px;
  line-height: 1.25;
  color: var(--ink);
}

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

.page-about .about-step p a {
  color: var(--ice);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .about-step p a:hover,
.page-about .about-step p a:focus-visible {
  color: var(--pulse-hi);
}

/* ---------- 团队三块 4:3:2 ---------- */

.page-about .about-team {
  display: grid;
  gap: 18px;
}

@media (min-width: 960px) {
  .page-about .about-team {
    grid-template-columns: 4fr 3fr 2fr;
    align-items: start;
    gap: 20px;
  }
}

.page-about .about-team__card {
  background: var(--about-card);
  border: 2px solid var(--edge);
  box-shadow: var(--shadow-hard-sm);
  padding: 20px 18px 22px;
  transition: transform 0.24s var(--ease), border-color 0.24s var(--ease);
}

@media (min-width: 960px) {
  .page-about .about-team__card:nth-child(2) {
    margin-top: 22px;
  }
  .page-about .about-team__card:nth-child(3) {
    margin-top: 44px;
  }
}

.page-about .about-team__card:hover,
.page-about .about-team__card:focus-within {
  transform: translateY(-6px);
  border-color: var(--pulse-hi);
}

.page-about .about-team__role {
  margin: 0;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--channel);
}

.page-about .about-team__count {
  display: flex;
  align-items: baseline;
  gap: 6px;
  margin: 10px 0 14px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--edge);
}

.page-about .about-team__num {
  font-family: var(--font-mono);
  font-size: 42px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.01em;
  color: var(--ice);
}

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

.page-about .about-team__card .tile__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--ink);
}

.page-about .about-team__duty {
  margin: 14px 0 0;
  padding-top: 12px;
  border-top: 1px dashed var(--edge);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--muted);
  transition: opacity 0.24s var(--ease), transform 0.24s var(--ease), color 0.24s var(--ease);
}

@media (hover: hover) {
  .page-about .about-team__duty {
    opacity: 0;
    transform: translateY(-4px);
  }
  .page-about .about-team__card:hover .about-team__duty,
  .page-about .about-team__card:focus-within .about-team__duty {
    opacity: 1;
    transform: none;
    color: var(--ice);
  }
}

/* ---------- 合作 ---------- */

.page-about .about-partners {
  display: grid;
  gap: 2px;
  border-left: 2px solid var(--edge);
}

.page-about .about-partner {
  padding: 18px 18px 20px;
  background: var(--about-card);
  border-top: 2px solid var(--edge);
  border-right: 2px solid var(--edge);
  border-bottom: 2px solid var(--edge);
  transition: background 0.24s var(--ease), padding-left 0.24s var(--ease);
}

.page-about .about-partner:last-child {
  border-bottom: 2px solid var(--edge);
}

.page-about .about-partner:hover {
  background: var(--tier);
  padding-left: 26px;
}

.page-about .about-partner__num {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 18px;
  letter-spacing: 0.01em;
  color: var(--ink);
}

.page-about .about-partner p:last-child {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--muted);
}

@media (min-width: 900px) {
  .page-about .about-partners {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0;
  }
  .page-about .about-partner {
    border-bottom: 2px solid var(--edge);
    border-top: 2px solid var(--edge);
    border-right: 0;
    border-left: 0;
  }
  .page-about .about-partner + .about-partner {
    border-left: 2px solid var(--edge);
  }
}

/* ---------- 时间轴 ---------- */

.page-about .about-timeline {
  position: relative;
  margin-top: 8px;
  padding-left: 34px;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 8px;
  top: 6px;
  bottom: 6px;
  width: 2px;
  background: linear-gradient(180deg, var(--pulse) 0%, var(--channel) 46%, var(--ice) 100%);
}

.page-about .about-timeline .accordion {
  display: grid;
  gap: 14px;
}

.page-about .about-timeline .accordion__item {
  position: relative;
}

.page-about .about-timeline .accordion__item::before {
  content: "";
  position: absolute;
  left: -32px;
  top: 22px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--tier);
  border: 2px solid var(--edge);
  z-index: 1;
}

.page-about .about-timeline .accordion__item--major::before {
  background: var(--pulse);
  border-color: var(--pulse);
  box-shadow: 0 0 0 5px rgba(255, 77, 46, 0.18);
}

.page-about .about-timeline .accordion__item--minor::before {
  background: var(--night);
  border-color: var(--ice);
}

.page-about .about-version__head {
  margin: 0;
  font-size: inherit;
  font-weight: inherit;
}

.page-about .about-version__trigger {
  width: 100%;
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px 14px;
  padding: 16px 18px;
  background: var(--about-card);
  border: 2px solid var(--edge);
  color: var(--ink);
  text-align: left;
  font: inherit;
  cursor: pointer;
  transition: border-color 0.24s var(--ease), background 0.24s var(--ease);
}

.page-about .about-version__trigger:hover,
.page-about .about-version__trigger:focus-visible {
  border-color: var(--pulse-hi);
}

.page-about .about-version__code {
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--pulse);
  flex: 0 0 auto;
}

.page-about .about-version__title {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 18px;
  line-height: 1.3;
  color: var(--ink);
  flex: 1 1 auto;
  min-width: 0;
}

.page-about .about-version__hint {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--muted);
  flex: 0 0 auto;
}

.page-about .about-version__tag {
  flex: 0 0 auto;
}

.page-about .about-version .accordion__panel {
  background: var(--night);
  border: 2px solid var(--edge);
  border-top: 0;
}

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

.page-about .about-version .accordion__inner p {
  margin: 0 0 12px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
}

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

.page-about .about-version .accordion__inner a {
  color: var(--ice);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .about-version .accordion__inner a:hover,
.page-about .about-version .accordion__inner a:focus-visible {
  color: var(--pulse-hi);
}

/* ---------- 联系收束 ---------- */

.page-about .about-reach {
  display: grid;
  gap: 18px;
  margin-bottom: 22px;
}

@media (min-width: 860px) {
  .page-about .about-reach {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 24px;
  }
}

.page-about .about-reach__col {
  background: var(--about-card);
  border: 2px solid var(--edge);
  border-left: 4px solid var(--channel);
  padding: 20px 18px 22px;
}

.page-about .about-reach__col:last-child {
  border-left-color: var(--ice);
}

.page-about .about-reach__col h3 {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 18px;
  color: var(--ink);
}

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

.page-about .about-reach__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  padding-top: 6px;
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-index__link,
  .page-about .about-step,
  .page-about .about-team__card,
  .page-about .about-team__duty,
  .page-about .about-partner,
  .page-about .about-version__trigger,
  .page-about .about-chapter {
    transition: none;
  }
  .page-about .about-team__card:hover,
  .page-about .about-index__link:hover {
    transform: none;
  }
}

.page-about {
  --step: var(--step-gap);
}