.page-about {
  --about-line-light: rgba(185, 234, 242, .24);
  --about-gap: clamp(1.5rem, 3vw, 3rem);
  background: var(--c-paper);
  color: var(--c-ink);
  font-family: var(--font-body);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  color: var(--c-paper);
  background:
    linear-gradient(118deg, var(--c-deep) 0 58%, #0d3450 58% 100%);
  padding: clamp(1.4rem, 3vw, 2.2rem) 0 clamp(2.6rem, 6vw, 4.6rem);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  right: -12%;
  top: -25%;
  width: 46%;
  height: 160%;
  background: repeating-linear-gradient(90deg,
      rgba(185, 234, 242, .15) 0 1px,
      transparent 1px 28px);
  transform: skewX(-14deg);
  pointer-events: none;
}

.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
}

.page-about .about-hero .breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .35rem;
  list-style: none;
  margin: 0 0 clamp(1.6rem, 4vw, 2.6rem);
  padding: 0;
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .1em;
  color: var(--c-mist);
}

.page-about .about-hero .breadcrumb__item {
  display: inline-flex;
  align-items: center;
  gap: .35rem;
  color: var(--c-mist);
}

.page-about .about-hero .breadcrumb__item::after {
  content: "/";
  color: rgba(185, 234, 242, .4);
}

.page-about .about-hero .breadcrumb__item:last-child::after {
  content: "";
}

.page-about .about-hero .breadcrumb__link {
  color: var(--c-ice);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

.page-about .about-hero .breadcrumb__link:hover,
.page-about .about-hero .breadcrumb__link:focus-visible {
  color: var(--c-paper);
  border-bottom-color: var(--c-lime);
}

.page-about .about-hero__kicker {
  margin: 0 0 1rem;
  font-family: var(--font-mono);
  font-size: .74rem;
  letter-spacing: .24em;
  color: var(--c-lime);
}

.page-about .about-hero__title {
  margin: 0 0 1.3rem;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.95rem, 5.6vw, 3.75rem);
  line-height: 1.06;
  letter-spacing: -.01em;
  color: var(--c-paper);
  max-width: 20ch;
}

.page-about .about-hero__lead {
  margin: 0 0 clamp(2rem, 4.5vw, 3rem);
  max-width: 54ch;
  font-size: var(--step-0);
  line-height: 1.8;
  color: var(--c-ice);
}

.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.1rem 1.4rem;
  padding-top: clamp(1.2rem, 3vw, 1.8rem);
  border-top: 1px solid var(--about-line-light);
}

.page-about .about-hero__stat {
  display: flex;
  flex-direction: column;
  gap: .3rem;
}

.page-about .about-hero__num {
  font-family: var(--font-mono);
  font-size: clamp(1.4rem, 3.4vw, 2.15rem);
  font-weight: 600;
  line-height: 1;
  color: var(--c-lime);
  letter-spacing: -.02em;
}

.page-about .about-hero__label {
  font-size: .78rem;
  line-height: 1.5;
  color: rgba(185, 234, 242, .72);
}

/* ---------- 章节骨架 ---------- */
.page-about .about-chapter {
  padding: clamp(2.6rem, 6vw, 5.4rem) 0;
}

.page-about .about-chapter--paper {
  background: var(--c-paper);
  color: var(--c-ink);
}

.page-about .about-chapter--night {
  background: var(--c-night);
  color: var(--c-paper);
}

.page-about .about-chapter--indigo {
  background: var(--c-indigo);
  color: var(--c-paper);
}

.page-about .about-chapter__inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.4rem, 3vw, 2.2rem);
}

.page-about .about-chapter__lede {
  position: relative;
}

.page-about .about-chapter__index {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(2.2rem, 6.5vw, 3.9rem);
  font-weight: 700;
  line-height: .9;
  letter-spacing: -.03em;
  color: var(--c-deep);
}

.page-about .about-chapter--night .about-chapter__index,
.page-about .about-chapter--indigo .about-chapter__index {
  color: var(--c-lime);
}

.page-about .about-chapter__rule {
  display: block;
  width: 36px;
  height: 2px;
  margin: .9rem 0 .8rem;
  background: var(--c-mist);
}

.page-about .about-chapter__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.35rem, 2.8vw, 2rem);
  line-height: 1.18;
  letter-spacing: -.005em;
}

.page-about .about-chapter__body {
  max-width: 64ch;
}

.page-about .about-chapter__body p {
  margin: 0 0 1.05em;
  font-size: var(--step-0);
  line-height: 1.8;
}

.page-about .about-chapter--night .about-chapter__body p,
.page-about .about-chapter--indigo .about-chapter__body p {
  color: rgba(246, 243, 234, .86);
}

.page-about .about-link {
  color: inherit;
  font-weight: 600;
  text-decoration: none;
  border-bottom: 1px solid currentColor;
  padding-bottom: 1px;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-chapter--night .about-link,
.page-about .about-chapter--indigo .about-link {
  color: var(--c-lime);
}

.page-about .about-link:hover,
.page-about .about-link:focus-visible {
  color: var(--c-orange);
  border-bottom-color: var(--c-orange);
}

/* ---------- 侧栏数据 ---------- */
.page-about .about-chapter__aside {
  border-top: 1px solid rgba(7, 16, 24, .16);
  padding-top: 1rem;
}

.page-about .about-chapter--night .about-chapter__aside,
.page-about .about-chapter--indigo .about-chapter__aside {
  border-top-color: var(--about-line-light);
}

.page-about .about-chapter__aside-title {
  margin: 0 0 1rem;
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .2em;
  color: var(--c-mist);
}

.page-about .about-facts {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: .9rem;
}

.page-about .about-facts__item {
  display: grid;
  gap: .2rem;
  padding-bottom: .85rem;
  border-bottom: 1px solid rgba(7, 16, 24, .12);
}

.page-about .about-chapter--night .about-facts__item,
.page-about .about-chapter--indigo .about-facts__item {
  border-bottom-color: var(--about-line-light);
}

.page-about .about-facts__item:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.page-about .about-facts__k {
  font-family: var(--font-mono);
  font-size: .82rem;
  font-weight: 600;
  letter-spacing: .02em;
  color: var(--c-deep);
}

.page-about .about-chapter--night .about-facts__k,
.page-about .about-chapter--indigo .about-facts__k {
  color: var(--c-lime);
}

.page-about .about-facts__v {
  font-size: .8rem;
  line-height: 1.6;
  color: var(--c-mist);
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: 1.8rem 0 1.6rem;
}

.page-about .about-figure__media {
  position: relative;
  overflow: hidden;
  border: 1px solid rgba(7, 16, 24, .16);
  background: var(--c-night);
  box-shadow: 8px 8px 0 -1px rgba(185, 234, 242, .28);
}

.page-about .about-chapter--night .about-figure__media {
  border-color: var(--about-line-light);
  box-shadow: 8px 8px 0 -1px rgba(183, 255, 60, .22);
}

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

.page-about .about-figure__media--4x3 {
  aspect-ratio: 4 / 3;
}

.page-about .about-figure__media--4x3 img {
  height: 100%;
}

.page-about .about-figure__media--3x2 {
  aspect-ratio: 3 / 2;
}

.page-about .about-figure__media--3x2 img {
  height: 100%;
}

.page-about .about-figure__caption {
  margin-top: .7rem;
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .04em;
  line-height: 1.6;
  color: var(--c-mist);
}

/* ---------- 能力卡片 ---------- */
.page-about .about-caps {
  display: grid;
  gap: 1rem;
  margin: 1.6rem 0 2rem;
}

.page-about .about-cap {
  position: relative;
  display: grid;
  align-content: start;
  gap: .45rem;
  padding: 1.2rem 1.1rem 1.25rem;
  background: rgba(6, 26, 43, .55);
  border: 1px solid var(--about-line-light);
  border-left: 3px solid var(--c-lime);
  transition:
    transform var(--dur) var(--ease),
    border-color var(--dur) var(--ease),
    box-shadow var(--dur) var(--ease);
}

.page-about .about-cap:hover {
  transform: translateY(-3px);
  border-color: rgba(185, 234, 242, .55);
  box-shadow: 0 10px 0 -6px rgba(185, 234, 242, .35);
}

.page-about .about-cap__index {
  font-family: var(--font-mono);
  font-size: .8rem;
  letter-spacing: .16em;
  color: var(--c-lime);
}

.page-about .about-cap__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.16rem;
  line-height: 1.25;
  color: var(--c-paper);
}

.page-about .about-cap__text {
  margin: 0;
  font-size: .9rem;
  line-height: 1.75;
  color: rgba(246, 243, 234, .82);
}

.page-about .about-cap__meta {
  margin: .25rem 0 0;
  padding-top: .6rem;
  border-top: 1px solid rgba(185, 234, 242, .2);
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .03em;
  line-height: 1.6;
  color: var(--c-ice);
}

/* ---------- 里程碑 ---------- */
.page-about .about-milestones {
  list-style: none;
  margin: 1.8rem 0 0;
  padding: 0;
  display: grid;
  gap: .85rem;
}

.page-about .about-milestone details {
  background: #fff;
  border: 1px solid rgba(7, 16, 24, .16);
  border-left: 4px solid var(--c-wine);
  transition: box-shadow var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-milestone details:hover {
  border-color: rgba(107, 32, 57, .45);
}

.page-about .about-milestone details[open] {
  box-shadow: 10px 10px 0 -6px rgba(7, 16, 24, .16);
}

.page-about .about-milestone summary {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: .9rem;
  padding: .95rem 1.05rem;
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-milestone summary::marker {
  content: "";
}

.page-about .about-milestone summary:focus-visible {
  outline: 2px solid var(--c-deep);
  outline-offset: -3px;
}

.page-about .about-milestone__stage {
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .12em;
  color: var(--c-wine);
  white-space: nowrap;
}

.page-about .about-milestone__name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1rem, 2vw, 1.18rem);
  line-height: 1.3;
  color: var(--c-ink);
}

.page-about .about-milestone__toggle::before {
  content: "+";
  display: inline-block;
  width: 1.3rem;
  text-align: center;
  font-family: var(--font-mono);
  font-size: 1.1rem;
  line-height: 1;
  color: var(--c-wine);
}

.page-about .about-milestone details[open] .about-milestone__toggle::before {
  content: "−";
}

.page-about .about-milestone__detail {
  padding: 0 1.05rem 1.15rem;
  max-width: 62ch;
}

.page-about .about-milestone__detail p {
  margin: 0 0 .9em;
  font-size: .92rem;
  line-height: 1.78;
  color: rgba(7, 16, 24, .82);
}

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

/* ---------- 团队 ---------- */
.page-about .about-crew {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
  margin: 1.5rem 0 1.8rem;
}

.page-about .about-crew__item {
  border-top: 2px solid var(--c-lime);
  padding-top: .7rem;
}

.page-about .about-crew__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.4rem, 3.4vw, 1.85rem);
  font-weight: 600;
  line-height: 1;
  color: var(--c-paper);
}

.page-about .about-crew__label {
  display: block;
  margin-top: .35rem;
  font-size: .76rem;
  line-height: 1.5;
  color: rgba(185, 234, 242, .74);
}

.page-about .about-tags {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem;
  list-style: none;
  margin: 1.4rem 0 0;
  padding: 0;
}

.page-about .about-tags li {
  padding: .42rem .8rem;
  border: 1px solid rgba(185, 234, 242, .3);
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .05em;
  color: var(--c-ice);
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

.page-about .about-tags li:hover {
  border-color: var(--c-lime);
  color: var(--c-lime);
}

/* ---------- 下一步入口 ---------- */
.page-about .about-next {
  background: var(--c-deep);
  color: var(--c-paper);
  padding: clamp(2.4rem, 6vw, 4.2rem) 0;
}

.page-about .about-next__kicker {
  margin: 0 0 .9rem;
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .24em;
  color: var(--c-lime);
}

.page-about .about-next__title {
  margin: 0 0 1.8rem;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.5rem, 3.4vw, 2.3rem);
  line-height: 1.2;
  color: var(--c-paper);
}

.page-about .about-next__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: .9rem;
}

.page-about .about-next__link {
  display: grid;
  gap: .35rem;
  align-content: start;
  padding: 1.15rem 1.1rem;
  text-decoration: none;
  color: var(--c-paper);
  border: 1px solid var(--about-line-light);
  background: rgba(11, 46, 68, .35);
  transition:
    transform var(--dur) var(--ease),
    border-color var(--dur) var(--ease),
    background-color var(--dur) var(--ease);
}

.page-about .about-next__link:hover,
.page-about .about-next__link:focus-visible {
  transform: translateY(-3px);
  border-color: var(--c-orange);
  background: rgba(11, 46, 68, .7);
}

.page-about .about-next__no {
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .16em;
  color: var(--c-lime);
}

.page-about .about-next__name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.12rem;
  line-height: 1.3;
}

.page-about .about-next__desc {
  font-size: .82rem;
  line-height: 1.65;
  color: rgba(185, 234, 242, .78);
}

/* ---------- 响应式 ---------- */
@media (min-width: 680px) {
  .page-about .about-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-caps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1.1rem;
  }

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

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

  .page-about .about-milestone:nth-child(even) {
    margin-left: clamp(0px, 5vw, 56px);
  }
}

@media (min-width: 920px) {
  .page-about .about-chapter__inner {
    grid-template-columns: minmax(150px, 190px) minmax(0, 1fr);
    column-gap: var(--about-gap);
    align-items: start;
  }

  .page-about .about-chapter__inner--aside {
    grid-template-columns: minmax(150px, 190px) minmax(0, 1fr) minmax(200px, 250px);
  }

  .page-about .about-chapter__aside {
    position: sticky;
    top: 2rem;
  }

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

  .page-about .about-hero::after {
    width: 40%;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-cap,
  .page-about .about-next__link,
  .page-about .about-tags li,
  .page-about .about-link,
  .page-about .about-milestone details {
    transition: none;
  }

  .page-about .about-cap:hover,
  .page-about .about-next__link:hover {
    transform: none;
  }
}