.page-about {
  --about-axis: 118px;
  --about-dot: 12px;
  background: var(--snow);
  color: var(--graphite);
  overflow-x: clip;
}

.page-about img {
  max-width: 100%;
  height: auto;
}

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

/* ============ 首屏 ============ */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(1.5rem, 4vw, 2.5rem) 0 clamp(2.5rem, 7vw, 4.75rem);
  color: var(--snow);
  background:
    radial-gradient(120% 95% at 84% 4%, rgba(30, 127, 208, 0.38), transparent 62%),
    radial-gradient(95% 75% at 4% 102%, rgba(255, 122, 47, 0.24), transparent 64%),
    var(--ink);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    repeating-linear-gradient(90deg, rgba(187, 221, 243, 0.07) 0 1px, transparent 1px 96px),
    repeating-linear-gradient(0deg, rgba(187, 221, 243, 0.05) 0 1px, transparent 1px 96px);
}

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

.page-about .about-hero .breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: clamp(1.25rem, 4vw, 2.25rem);
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--mist);
}

.page-about .about-hero .breadcrumbs__item {
  color: inherit;
  text-decoration: none;
}

.page-about .about-hero .breadcrumbs__item:not(:last-child)::after {
  content: "/";
  margin-left: 0.5rem;
  color: var(--blue-lt);
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(2rem, 5vw, 3rem);
  align-items: start;
}

.page-about .about-hero h1 {
  margin: 0.7rem 0 1.05rem;
  max-width: 15ch;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(2rem, 6.4vw, 3.5rem);
  line-height: 1.08;
  letter-spacing: -0.02em;
  color: var(--snow);
}

.page-about .about-hero__intro {
  margin: 0;
  max-width: 46ch;
  font-size: clamp(1rem, 1.9vw, 1.1875rem);
  line-height: 1.85;
  color: rgba(244, 247, 251, 0.84);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem;
  margin-top: 1.85rem;
}

.page-about .about-hero__actions .btn {
  font-family: var(--font-display);
  font-weight: 800;
}

.page-about .about-hero__figure {
  margin: 0;
  position: relative;
}

.page-about .about-hero__figure img {
  display: block;
  width: 100%;
  height: auto;
  border: 3px solid var(--blue-lt);
  box-shadow: 10px 10px 0 rgba(255, 122, 47, 0.9);
}

.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(2.25rem, 6vw, 3.25rem) 0 0;
  padding: 1px;
  background: rgba(187, 221, 243, 0.24);
}

.page-about .about-hero__stat {
  background: rgba(22, 39, 77, 0.86);
  padding: 1rem 1.15rem 1.1rem;
}

.page-about .about-hero__stat dt {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.09em;
  color: var(--mist);
}

.page-about .about-hero__stat dd {
  margin: 0.45rem 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.45rem, 3.4vw, 1.95rem);
  line-height: 1;
  color: var(--orange);
}

/* ============ 章节索引 ============ */
.page-about .about-toc {
  position: sticky;
  top: var(--header-h);
  z-index: 18;
  padding: 0.85rem 0;
  background: rgba(244, 247, 251, 0.96);
  border-bottom: 1px solid rgba(11, 27, 58, 0.12);
  backdrop-filter: blur(8px);
}

.page-about .toc {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.6rem 0.9rem;
}

.page-about .toc__title {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--gray);
}

.page-about .toc__list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .toc__link {
  display: inline-block;
  padding: 0.32rem 0.75rem;
  border: 2px solid rgba(11, 27, 58, 0.16);
  background: #fff;
  font-size: 0.875rem;
  color: var(--ink);
  text-decoration: none;
  transition: border-color 0.2s ease, background 0.2s ease, color 0.2s ease;
}

.page-about .toc__link:hover,
.page-about .toc__link.is-active {
  border-color: var(--orange);
  background: var(--orange);
  color: var(--ink);
}

/* ============ 通用章节标题 ============ */
.page-about .about-chapter {
  background: var(--snow);
}

.page-about .about-head {
  max-width: 60ch;
  margin-bottom: clamp(1.9rem, 5vw, 3rem);
}

.page-about .about-head h2 {
  margin: 0.55rem 0 0.85rem;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.6rem, 4.4vw, 2.25rem);
  line-height: 1.14;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.page-about .about-head p {
  margin: 0;
  font-size: 1.0625rem;
  line-height: 1.85;
  color: #3a4a63;
}

/* ============ 纵向时间轴 ============ */
.page-about .timeline {
  position: relative;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  top: 0.6rem;
  bottom: 1.6rem;
  left: 5px;
  width: 2px;
  background: linear-gradient(180deg, var(--orange), var(--blue) 48%, var(--mist));
}

.page-about .timeline__item {
  position: relative;
  padding: 0 0 2.1rem 2.1rem;
}

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.5rem;
  width: var(--about-dot);
  height: var(--about-dot);
  border-radius: 50%;
  background: var(--blue);
  box-shadow: 0 0 0 4px var(--snow);
  z-index: 1;
}

.page-about .timeline__item--key::before {
  background: var(--orange);
}

.page-about .timeline__idx {
  display: block;
  margin-bottom: 0.45rem;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--orange);
}

.page-about .timeline__body h3 {
  margin: 0 0 0.45rem;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 1.22rem;
  line-height: 1.32;
  color: var(--ink);
}

.page-about .timeline__body p {
  margin: 0;
  max-width: 56ch;
  font-size: 1rem;
  line-height: 1.85;
  color: #46566f;
}

/* ============ 中段横向主题带 ============ */
.page-about .about-band {
  position: relative;
  padding: clamp(2.6rem, 7vw, 4.25rem) 0 clamp(2.4rem, 6vw, 3.75rem);
  background: var(--ink-2);
  color: var(--snow);
  overflow: hidden;
}

.page-about .about-band__rail {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 10px;
  background: repeating-linear-gradient(-45deg, var(--orange) 0 18px, var(--blue) 18px 36px);
}

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

.page-about .about-band h2 {
  margin: 0.6rem 0 0.9rem;
  max-width: 22ch;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.55rem, 4.2vw, 2.2rem);
  line-height: 1.16;
  color: var(--snow);
}

.page-about .about-band__lede {
  margin: 0;
  max-width: 52ch;
  font-size: 1.0625rem;
  line-height: 1.85;
  color: rgba(244, 247, 251, 0.82);
}

.page-about .about-band__bar {
  display: flex;
  gap: 5px;
  margin-top: clamp(1.6rem, 4vw, 2.25rem);
}

.page-about .about-band__seg {
  height: 16px;
  background: linear-gradient(90deg, rgba(30, 127, 208, 0.85), rgba(79, 179, 232, 0.85));
  border: 1px solid rgba(187, 221, 243, 0.3);
}

.page-about .about-band__seg:nth-child(1) { flex: 1; }
.page-about .about-band__seg:nth-child(2) { flex: 1.35; }
.page-about .about-band__seg:nth-child(3) { flex: 1.8; }
.page-about .about-band__seg:nth-child(4) { flex: 2.3; }
.page-about .about-band__seg:nth-child(5) { flex: 2.9; }
.page-about .about-band__seg:nth-child(6) { flex: 3.6; }

.page-about .about-band__seg--now {
  background: linear-gradient(90deg, var(--orange), var(--orange-lt));
  border-color: rgba(255, 192, 138, 0.6);
}

.page-about .about-band__scale {
  margin: 1.1rem 0 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  line-height: 2;
  color: var(--mist);
}

/* ============ 版本清单 ============ */
.page-about .versions {
  display: grid;
  gap: 1px;
  margin: 0;
  padding: 1px;
  list-style: none;
  background: rgba(11, 27, 58, 0.16);
}

.page-about .versions__item {
  padding: 1.3rem 1.35rem 1.45rem;
  background: #fff;
  border-left: 4px solid transparent;
  transition: border-color 0.2s ease, background 0.2s ease;
}

.page-about .versions__item:hover {
  border-left-color: var(--orange);
  background: #fffbf6;
}

.page-about .versions__no {
  display: inline-block;
  margin-bottom: 0.7rem;
  padding: 0.1rem 0.5rem;
  border: 2px solid var(--blue);
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--blue);
}

.page-about .versions__item h3 {
  margin: 0 0 0.45rem;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 1.12rem;
  line-height: 1.34;
  color: var(--ink);
}

.page-about .versions__item p {
  margin: 0;
  font-size: 1rem;
  line-height: 1.8;
  color: #46566f;
}

.page-about .about-chapter__figure {
  margin: clamp(2rem, 5vw, 2.75rem) 0 0;
  border: 3px solid var(--ink);
  box-shadow: 10px 10px 0 rgba(30, 127, 208, 0.32);
}

/* ============ 团队 ============ */
.page-about .team-tree {
  display: block;
  width: 100%;
  max-width: 520px;
  height: auto;
  margin: 0 0 clamp(1.75rem, 4vw, 2.5rem);
}

.page-about .team-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(1.75rem, 5vw, 3rem);
  align-items: start;
}

.page-about .team-node {
  position: relative;
  padding: 1.15rem 1.25rem 1.3rem;
  background: #fff;
  border: 2px solid var(--ink);
  box-shadow: 6px 6px 0 rgba(11, 27, 58, 0.14);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.page-about .team-node:hover {
  transform: translate(4px, 4px);
  box-shadow: 2px 2px 0 rgba(11, 27, 58, 0.2);
}

.page-about .team-node + .team-node {
  margin-top: 1.15rem;
}

.page-about .team-node__num {
  margin: 0 0 0.4rem;
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--orange);
}

.page-about .team-node h3 {
  margin: 0 0 0.4rem;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 1.15rem;
  color: var(--ink);
}

.page-about .team-node p {
  margin: 0;
  font-size: 1rem;
  line-height: 1.8;
  color: #46566f;
}

.page-about .team-figure {
  margin: 0;
  border: 3px solid var(--ink);
  box-shadow: 10px 10px 0 rgba(255, 122, 47, 0.4);
}

/* ============ 内容来源 ============ */
.page-about .source-rows {
  border-top: 2px solid var(--ink);
}

.page-about .source-row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.65rem;
  padding: 1.4rem 0 1.5rem;
  border-bottom: 1px solid rgba(11, 27, 58, 0.16);
}

.page-about .source-row__label {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.09em;
  color: var(--orange);
}

.page-about .source-row__body p {
  margin: 0;
  font-size: 1.0625rem;
  line-height: 1.85;
  color: #35445c;
}

.page-about .source-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 0 0 0.85rem;
  padding: 0;
  list-style: none;
}

.page-about .source-tags li {
  padding: 0.28rem 0.75rem;
  border: 2px solid var(--blue);
  background: rgba(30, 127, 208, 0.08);
  font-size: 0.9rem;
  color: var(--ink);
}

/* ============ 三件事 ============ */
.page-about .about-keep {
  position: relative;
  background:
    radial-gradient(90% 80% at 12% 0%, rgba(30, 127, 208, 0.26), transparent 60%),
    var(--ink);
  color: var(--snow);
  padding-bottom: clamp(2.5rem, 7vw, 4.5rem);
}

.page-about .about-head--dark h2 {
  color: var(--snow);
}

.page-about .keep-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.15rem;
}

.page-about .keep-card {
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
  padding: 1.5rem 1.35rem 1.4rem;
  background: var(--ink-2);
  border: 2px solid rgba(187, 221, 243, 0.3);
  box-shadow: 8px 8px 0 rgba(5, 12, 28, 0.85);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.page-about .keep-card:hover {
  transform: translate(4px, 4px);
  box-shadow: 3px 3px 0 rgba(5, 12, 28, 0.95);
}

.page-about .keep-card__no {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 22px;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--orange);
}

.page-about .keep-card h3 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 1.2rem;
  color: var(--snow);
}

.page-about .keep-card p {
  margin: 0;
  font-size: 1rem;
  line-height: 1.8;
  color: rgba(244, 247, 251, 0.82);
}

.page-about .keep-card .btn {
  align-self: flex-start;
  margin-top: 0.35rem;
}

.page-about .about-keep__more {
  margin: clamp(2.25rem, 6vw, 3.25rem) 0 0;
  font-size: 1rem;
  line-height: 1.9;
  color: rgba(244, 247, 251, 0.78);
}

.page-about .about-keep__more a {
  color: var(--orange-lt);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .about-keep__more a:hover {
  color: var(--snow);
}

/* ============ 响应式 ============ */
@media (min-width: 700px) {
  .page-about .about-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

@media (min-width: 860px) {
  .page-about .about-hero__grid {
    grid-template-columns: 7fr 5fr;
    gap: clamp(2rem, 4vw, 3.5rem);
  }

  .page-about .about-hero__figure {
    margin-top: 1.5rem;
  }

  .page-about .timeline::before {
    left: var(--about-axis);
  }

  .page-about .timeline__item {
    display: grid;
    grid-template-columns: 104px minmax(0, 1fr);
    column-gap: 2.75rem;
    padding: 0 0 2.6rem;
  }

  .page-about .timeline__item::before {
    left: 112px;
    top: 0.65rem;
    width: 14px;
    height: 14px;
  }

  .page-about .timeline__idx {
    padding-top: 0.35rem;
    margin-bottom: 0;
    text-align: right;
    font-size: 14px;
    color: var(--gray);
  }

  .page-about .timeline__item--key .timeline__idx {
    color: var(--orange);
  }

  .page-about .source-row {
    grid-template-columns: 190px minmax(0, 1fr);
    gap: 2.25rem;
    align-items: start;
  }

  .page-about .source-row__label {
    padding-top: 0.2rem;
  }
}

@media (min-width: 980px) {
  .page-about .versions {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .team-grid {
    grid-template-columns: 6fr 5fr;
    gap: clamp(2rem, 4vw, 3.25rem);
  }

  .page-about .keep-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1.35rem;
  }

  .page-about .keep-card:nth-child(2) {
    margin-top: 1.75rem;
  }

  .page-about .keep-card:nth-child(3) {
    margin-top: 0.85rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .team-node,
  .page-about .keep-card,
  .page-about .versions__item,
  .page-about .toc__link {
    transition: none;
  }

  .page-about .team-node:hover,
  .page-about .keep-card:hover {
    transform: none;
  }
}