.page-about {
  background: var(--warm);
  color: var(--charcoal);
  font-family: var(--font-body);
  line-height: 1.75;
  overflow-x: clip;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  padding: calc(var(--hdr-h) + clamp(1.8rem, 6vw, 3.6rem)) 0 clamp(2.2rem, 6vw, 4.2rem);
  background: var(--fog-blue-ink);
  color: var(--warm);
  overflow: hidden;
}
.page-about .about-hero__media {
  position: absolute;
  inset: 0;
  z-index: 0;
}
.page-about .about-hero__media img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 62%;
}
.page-about .about-hero__veil {
  position: absolute;
  inset: 0;
  background: linear-gradient(168deg, rgba(11, 39, 56, 0.9) 0%, rgba(27, 79, 114, 0.74) 44%, rgba(5, 7, 8, 0.94) 100%);
}
.page-about .about-hero__trail {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 5px;
  background: linear-gradient(90deg, var(--neon) 0%, rgba(255, 107, 44, 0.25) 46%, transparent 78%);
}
.page-about .about-hero__inner {
  position: relative;
  z-index: 2;
}
.page-about .about-hero .crumbs {
  color: rgba(248, 244, 236, 0.7);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.04em;
}
.page-about .about-hero .crumbs a {
  color: rgba(248, 244, 236, 0.7);
  text-decoration: none;
}
.page-about .about-hero .crumbs a:hover {
  color: var(--neon-soft);
}
.page-about .about-hero .crumbs__current {
  color: var(--warm);
}
.page-about .about-hero .kicker,
.page-about .about-next__kicker {
  margin: 1.4rem 0 0;
  color: var(--neon-soft);
}
.page-about .about-hero h1 {
  margin: 0.9rem 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(2.15rem, 7.2vw, 4.4rem);
  line-height: 1.06;
  letter-spacing: -0.02em;
  color: #ffffff;
  max-width: 20ch;
}
.page-about .about-hero__lead {
  margin: 1.15rem 0 0;
  max-width: 60ch;
  font-size: clamp(1rem, 2.2vw, 1.16rem);
  line-height: 1.8;
  color: rgba(248, 244, 236, 0.86);
}
.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  margin-top: 1.7rem;
}

/* ---------- 数字带 ---------- */
.page-about .about-stats {
  background: var(--ink);
  color: var(--warm);
}
.page-about .about-stats__grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: rgba(248, 244, 236, 0.14);
  border-top: 1px solid rgba(248, 244, 236, 0.14);
  border-bottom: 1px solid rgba(248, 244, 236, 0.14);
}
.page-about .stat {
  background: var(--ink);
  padding: clamp(1rem, 3vw, 1.7rem) clamp(0.9rem, 2.6vw, 1.5rem);
}
.page-about .stat__num {
  display: block;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.85rem, 5.6vw, 2.8rem);
  line-height: 1;
  color: var(--neon);
}
.page-about .stat__label {
  margin: 0.45rem 0 0;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  letter-spacing: 0.04em;
  color: rgba(248, 244, 236, 0.64);
}

/* ---------- 章节索引 ---------- */
.page-about .about-index {
  position: sticky;
  top: var(--hdr-h);
  z-index: 20;
  background: var(--warm);
  border-bottom: var(--rule);
}
.page-about .about-index__inner {
  display: flex;
  gap: 0.4rem;
  overflow-x: auto;
  padding-top: 0.55rem;
  padding-bottom: 0.55rem;
  scrollbar-width: thin;
}
.page-about .about-index__link {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.4rem 0.7rem;
  border: 1px solid rgba(16, 20, 24, 0.16);
  border-radius: var(--radius);
  font-size: 0.86rem;
  color: rgba(16, 20, 24, 0.78);
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.25s var(--ease), border-color 0.25s var(--ease), background-color 0.25s var(--ease);
}
.page-about .about-index__link .mono {
  font-size: 0.72rem;
  color: var(--steel);
}
.page-about .about-index__link:hover {
  border-color: var(--neon);
  color: var(--charcoal);
}
.page-about .about-index__link[aria-current="true"] {
  background: var(--fog-blue);
  border-color: var(--fog-blue);
  color: #ffffff;
}
.page-about .about-index__link[aria-current="true"] .mono {
  color: var(--neon-soft);
}

/* ---------- 章节骨架 ---------- */
.page-about .about-section {
  scroll-margin-top: calc(var(--hdr-h) + 54px);
}
.page-about .about-chapter {
  display: grid;
  gap: 1.1rem;
  align-items: start;
}
.page-about .about-side {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  padding-bottom: 0.7rem;
  border-bottom: 1px solid rgba(16, 20, 24, 0.14);
}
.page-about .about-side__no {
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--neon);
}
.page-about .about-side__note {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  line-height: 1.6;
  color: var(--steel);
}
.page-about .about-body {
  min-width: 0;
}
.page-about .about-body h2 {
  margin: 0 0 1rem;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.65rem, 4.4vw, 2.65rem);
  line-height: 1.16;
  letter-spacing: -0.01em;
  color: var(--charcoal);
}
.page-about .about-body p {
  margin: 0 0 1rem;
  max-width: 64ch;
  font-size: 1.04rem;
  line-height: 1.8;
  color: rgba(16, 20, 24, 0.82);
}
.page-about .about-body h3 {
  margin: 0 0 0.45rem;
  font-size: 1.16rem;
  font-weight: 800;
  color: var(--fog-blue-ink);
}

/* ---------- 列表 ---------- */
.page-about .dot-list {
  list-style: none;
  margin: 1.1rem 0 0;
  padding: 0;
  display: grid;
  gap: 0.55rem;
}
.page-about .dot-list li {
  position: relative;
  padding-left: 1.15rem;
  font-size: 0.98rem;
  line-height: 1.75;
  color: rgba(16, 20, 24, 0.8);
}
.page-about .dot-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.78em;
  width: 0.55rem;
  height: 2px;
  background: var(--neon);
}

/* ---------- 双主线（深蓝带） ---------- */
.page-about .about-band--blue {
  background: linear-gradient(155deg, var(--fog-blue-ink) 0%, var(--fog-blue) 58%, var(--fog-blue-deep) 100%);
  color: var(--warm);
}
.page-about .about-band--blue .about-side {
  border-bottom-color: rgba(248, 244, 236, 0.22);
}
.page-about .about-band--blue .about-side__note {
  color: rgba(248, 244, 236, 0.66);
}
.page-about .about-band--blue .about-body h2 {
  color: #ffffff;
}
.page-about .about-band--blue .about-body p {
  color: rgba(248, 244, 236, 0.84);
}
.page-about .about-band--blue .dot-list li {
  color: rgba(248, 244, 236, 0.86);
}
.page-about .about-band--blue .about-body h3 {
  color: #ffffff;
}

.page-about .tabs {
  margin-top: 1.6rem;
}
.page-about .tabs__list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1.1rem;
}
.page-about .tabs__btn {
  appearance: none;
  cursor: pointer;
  padding: 0.6rem 1.05rem;
  border: 1px solid rgba(248, 244, 236, 0.36);
  border-radius: var(--radius);
  background: transparent;
  color: rgba(248, 244, 236, 0.8);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  letter-spacing: 0.05em;
  transition: background-color 0.25s var(--ease), border-color 0.25s var(--ease), color 0.25s var(--ease);
}
.page-about .tabs__btn:hover {
  border-color: var(--neon-soft);
  color: #ffffff;
}
.page-about .tabs__btn[aria-selected="true"] {
  background: var(--neon);
  border-color: var(--neon);
  color: #ffffff;
}
.page-about .tabs__panel[aria-hidden="true"] {
  display: none;
}
.page-about .tabs__panel + .tabs__panel {
  margin-top: 1rem;
}
.page-about .track-card {
  padding: clamp(1.15rem, 3vw, 1.85rem);
  background: rgba(5, 7, 8, 0.3);
  border: 1px solid rgba(248, 244, 236, 0.22);
  border-radius: var(--radius);
}
.page-about .tag-list {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  margin: 1.1rem 0 0;
  padding: 0;
}
.page-about .tag-list li {
  padding: 0.34rem 0.62rem;
  border: 1px solid rgba(248, 244, 236, 0.3);
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: 0.76rem;
  letter-spacing: 0.03em;
  color: rgba(248, 244, 236, 0.88);
  transition: border-color 0.25s var(--ease), color 0.25s var(--ease);
}
.page-about .tag-list li:hover {
  border-color: var(--neon);
  color: #ffffff;
}
.page-about .about-figure {
  margin: 1.8rem 0 0;
}
.page-about .media img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
}

/* ---------- 三步（浅雾蓝） ---------- */
.page-about .about-steps {
  list-style: none;
  margin: 1.6rem 0 0;
  padding: 0;
  display: grid;
  gap: 0.9rem;
}
.page-about .about-step {
  padding: 1.15rem 1.25rem;
  background: #ffffff;
  border: 1px solid rgba(16, 20, 24, 0.12);
  border-left: 3px solid var(--neon);
  border-radius: var(--radius);
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease);
}
.page-about .about-step:hover {
  transform: translateY(-3px);
  box-shadow: 6px 6px 0 -1px var(--paper), 6px 6px 0 0 rgba(16, 20, 24, 0.08);
}
.page-about .about-step__no {
  display: block;
  margin-bottom: 0.45rem;
  font-size: 0.76rem;
  letter-spacing: 0.14em;
  color: var(--neon);
}
.page-about .about-step p {
  margin: 0;
  font-size: 0.98rem;
  line-height: 1.75;
  color: rgba(16, 20, 24, 0.78);
}

/* ---------- 迭代时间线（纸灰） ---------- */
.page-about .timeline {
  list-style: none;
  margin: 1.7rem 0 0;
  padding: 0 0 0 1.25rem;
  border-left: 2px solid rgba(16, 20, 24, 0.16);
  display: grid;
  gap: 1.05rem;
}
.page-about .timeline__item {
  position: relative;
  padding: 1.05rem 1.15rem;
  background: #ffffff;
  border: 1px solid rgba(16, 20, 24, 0.12);
  border-radius: var(--radius);
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease), border-color 0.3s var(--ease);
}
.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: -1.25rem;
  top: 1.5rem;
  width: 10px;
  height: 10px;
  margin-left: -6px;
  background: var(--neon);
  border: 2px solid var(--paper);
}
.page-about .timeline__item:hover {
  transform: translateY(-3px);
  border-color: var(--fog-blue);
  box-shadow: 6px 6px 0 -1px var(--warm), 6px 6px 0 0 rgba(16, 20, 24, 0.08);
}
.page-about .timeline__tag {
  display: inline-block;
  margin-bottom: 0.45rem;
  padding: 0.2rem 0.5rem;
  background: var(--mist);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: var(--fog-blue-ink);
}
.page-about .timeline__item h3 {
  margin: 0 0 0.35rem;
}
.page-about .timeline__item p {
  margin: 0;
  font-size: 0.96rem;
  line-height: 1.72;
  color: rgba(16, 20, 24, 0.76);
}
.page-about .about-note {
  margin-top: 1.4rem;
  padding-left: 0.9rem;
  border-left: 3px solid var(--neon);
  font-size: 0.96rem;
  color: rgba(16, 20, 24, 0.78);
}
.page-about .about-note a {
  color: var(--fog-blue);
  text-decoration: underline;
  text-underline-offset: 3px;
}
.page-about .about-note a:hover {
  color: var(--neon);
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  display: grid;
  gap: 1.5rem;
  margin-top: 1.6rem;
}
.page-about .about-team__figure {
  margin: 0;
}
.page-about .about-team__text h3 {
  margin-bottom: 0.6rem;
}
.page-about .about-team__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  margin-top: 1.4rem;
}

/* ---------- 收尾 ---------- */
.page-about .about-band--ink {
  background: linear-gradient(160deg, var(--charcoal) 0%, var(--ink) 100%);
  color: var(--warm);
  border-top: 5px solid var(--neon);
}
.page-about .about-next__kicker {
  color: var(--neon-soft);
}
.page-about .about-next__title {
  margin: 0.7rem 0 1.6rem;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.5rem, 3.8vw, 2.3rem);
  line-height: 1.2;
  color: #ffffff;
}
.page-about .about-next__grid {
  display: grid;
  gap: 1rem;
}
.page-about .about-next__card {
  display: block;
  padding: 1.25rem 1.3rem;
  border: 1px solid rgba(248, 244, 236, 0.22);
  border-radius: var(--radius);
  text-decoration: none;
  color: var(--warm);
  transition: border-color 0.3s var(--ease), transform 0.3s var(--ease), background-color 0.3s var(--ease);
}
.page-about .about-next__card:hover {
  transform: translateY(-3px);
  border-color: var(--neon);
  background: rgba(255, 107, 44, 0.08);
}
.page-about .about-next__no {
  display: block;
  font-size: 0.74rem;
  letter-spacing: 0.14em;
  color: var(--neon);
}
.page-about .about-next__card h3 {
  margin: 0.5rem 0 0.4rem;
  font-size: 1.15rem;
  font-weight: 800;
  color: #ffffff;
}
.page-about .about-next__card p {
  margin: 0;
  font-size: 0.94rem;
  line-height: 1.7;
  color: rgba(248, 244, 236, 0.72);
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-stats__grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .about-steps {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .page-about .about-chapter {
    grid-template-columns: minmax(0, 220px) minmax(0, 1fr);
    gap: clamp(2rem, 4vw, 3.4rem);
  }
  .page-about .about-side {
    position: sticky;
    top: calc(var(--hdr-h) + 68px);
    flex-direction: column;
    gap: 0.5rem;
    padding-bottom: 0;
    border-bottom: none;
    border-left: 2px solid rgba(16, 20, 24, 0.14);
    padding-left: 0.95rem;
  }
  .page-about .about-band--blue .about-side {
    border-left-color: rgba(248, 244, 236, 0.24);
    border-bottom: none;
  }
  .page-about .about-team {
    grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
    align-items: start;
    gap: 2.4rem;
  }
  .page-about .about-next__grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1.2rem;
  }
  .page-about .about-hero h1 {
    max-width: 22ch;
  }
}

@media (min-width: 1120px) {
  .page-about .about-chapter {
    grid-template-columns: minmax(0, 250px) minmax(0, 1fr);
  }
}