.page-about {
  background: var(--ink);
  color: var(--mist);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  padding: calc(var(--header-space) + 20px) 0 clamp(36px, 6vw, 68px);
  border-bottom: 1px solid var(--line);
  background-color: var(--ink);
  background-image:
    linear-gradient(to right, rgba(30, 53, 80, .55) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(30, 53, 80, .55) 1px, transparent 1px);
  background-size: var(--grid-step) var(--grid-step);
  background-position: center top;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background:
    radial-gradient(660px 320px at 84% 6%, rgba(36, 224, 214, .16), transparent 70%),
    radial-gradient(520px 260px at 6% 96%, rgba(255, 122, 41, .12), transparent 72%);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--cyan), var(--orange) 46%, var(--gold));
}

.page-about .about-eyebrow {
  margin: 18px 0 0;
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--cyan);
}

.page-about .about-hero h1 {
  margin: 12px 0 0;
  max-width: 20em;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(30px, 6.2vw, 62px);
  line-height: 1.06;
  letter-spacing: -0.02em;
  color: var(--mist);
}

.page-about .about-lede {
  margin: 20px 0 0;
  max-width: 60ch;
  font-size: clamp(15px, 1.7vw, 17px);
  line-height: 1.78;
  color: var(--haze);
}

.page-about .about-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 34px 0 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-facts li {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 15px 16px;
  background: var(--panel);
}

.page-about .about-facts__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(21px, 3vw, 30px);
  line-height: 1.1;
  color: var(--gold);
}

.page-about .about-facts__key {
  font-size: 13px;
  line-height: 1.4;
  color: var(--haze);
}

/* ---------- 双轨布局 ---------- */
.page-about .about-duo {
  display: grid;
  gap: clamp(24px, 4vw, 48px);
  padding-top: clamp(36px, 6vw, 64px);
  padding-bottom: clamp(44px, 7vw, 88px);
}

.page-about .about-rail__title {
  margin: 0 0 10px;
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--haze);
}

.page-about .about-rail__list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0 0 10px;
  list-style: none;
  overflow-x: auto;
  overscroll-behavior-x: contain;
}

.page-about .about-rail__link {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 8px 12px;
  border: 1px solid var(--line);
  background: var(--panel);
  color: var(--haze);
  font-size: 13.5px;
  line-height: 1.3;
  text-decoration: none;
  white-space: nowrap;
  transition: color .18s ease, border-color .18s ease, background-color .18s ease;
}

.page-about .about-rail__link:hover {
  color: var(--mist);
  border-color: var(--haze);
}

.page-about .about-rail__link.is-active,
.page-about .about-rail__link[aria-current="true"] {
  color: var(--cyan);
  border-color: var(--cyan-edge);
  background: var(--cyan-soft);
}

.page-about .about-rail__no {
  font-size: 11px;
  color: var(--gold);
}

@media (min-width: 960px) {
  .page-about .about-duo {
    grid-template-columns: minmax(0, 196px) minmax(0, 1fr);
    gap: clamp(36px, 5vw, 72px);
    align-items: start;
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--header-space) + 14px);
  }

  .page-about .about-rail__list {
    display: block;
    overflow: visible;
    padding: 0;
  }

  .page-about .about-rail__link {
    display: block;
    padding: 9px 0 9px 14px;
    border: 0;
    border-left: 2px solid var(--line);
    background: none;
    white-space: normal;
    font-size: 14px;
  }

  .page-about .about-rail__link.is-active,
  .page-about .about-rail__link[aria-current="true"] {
    border-left-color: var(--cyan);
    background: none;
  }
}

/* ---------- 章节块 ---------- */
.page-about .about-block {
  padding-bottom: clamp(38px, 5.5vw, 68px);
}

.page-about .about-block + .about-block {
  padding-top: clamp(34px, 5vw, 58px);
  border-top: 1px solid var(--line);
}

.page-about .about-block:last-child {
  padding-bottom: 0;
}

.page-about .about-block__title {
  margin: 0 0 18px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(22px, 3.2vw, 32px);
  line-height: 1.26;
  letter-spacing: -0.01em;
  color: var(--mist);
}

.page-about .about-block__title::before {
  content: "";
  display: block;
  width: 32px;
  height: 3px;
  margin-bottom: 14px;
  background: var(--cyan);
}

.page-about :where(.about-block) p {
  max-width: 68ch;
  margin: 0 0 14px;
  font-size: 16px;
  line-height: 1.78;
  color: var(--haze);
}

.page-about .about-block__intro {
  margin-bottom: 20px;
  color: var(--haze);
}

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

/* ---------- 四条内容线 ---------- */
.page-about .line-track {
  display: grid;
  grid-auto-flow: column;
  grid-auto-columns: minmax(232px, 80%);
  gap: 12px;
  margin: 0 0 8px;
  padding: 0 0 12px;
  overflow-x: auto;
  overscroll-behavior-x: contain;
  scroll-snap-type: x proximity;
}

.page-about .line-track::-webkit-scrollbar {
  height: 6px;
}

.page-about .line-track::-webkit-scrollbar-thumb {
  background: var(--line);
}

.page-about .line-card {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 20px 18px 22px;
  background: var(--panel);
  border: 1px solid var(--line);
  scroll-snap-align: start;
  transition: transform .2s ease, border-color .2s ease;
}

.page-about .line-card:hover {
  transform: translateY(-4px);
  border-color: var(--cyan-edge);
}

.page-about .line-card .tag {
  align-self: flex-start;
}

.page-about .line-card__title {
  margin: 0;
  font-size: 17px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--mist);
}

.page-about .line-card p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--haze);
}

.page-about .line-card__meta {
  margin-top: auto;
  padding-top: 10px;
  border-top: 1px dashed var(--line);
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--haze);
}

@media (min-width: 780px) {
  .page-about .line-track {
    grid-auto-flow: row;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    overflow: visible;
    padding-bottom: 0;
    margin-bottom: 4px;
  }
}

.page-about .about-figure {
  margin-top: 24px;
}

.page-about .about-figure .frame__tag {
  color: var(--gold);
}

/* ---------- 团队 ---------- */
.page-about .team-split {
  display: grid;
  gap: 22px;
}

.page-about .team-note {
  margin-top: 22px;
  padding: 16px 18px;
  background: var(--panel);
  border-left: 3px solid var(--cyan);
}

.page-about .team-note p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--haze);
}

@media (min-width: 880px) {
  .page-about .team-split {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 32px;
    align-items: start;
  }
}

/* ---------- 规模与节奏 ---------- */
.page-about .scale-split {
  display: grid;
  gap: 22px;
  margin-bottom: 20px;
}

.page-about .scale-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .scale-cell {
  display: flex;
  flex-direction: column;
  gap: 5px;
  padding: 17px 16px;
  background: var(--panel);
}

.page-about .scale-cell__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(22px, 3.6vw, 32px);
  line-height: 1.1;
  color: var(--gold);
}

.page-about .scale-cell__key {
  font-size: 13px;
  line-height: 1.5;
  color: var(--haze);
}

.page-about .scale-note {
  margin: 0;
}

@media (min-width: 900px) {
  .page-about .scale-split {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: 30px;
    align-items: start;
  }
}

/* ---------- 阶段带 ---------- */
.page-about .stage-band {
  display: grid;
  gap: 1px;
  margin-top: 20px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .stage {
  position: relative;
  padding: 24px 20px 22px;
  background: var(--ink);
  transition: background-color .2s ease;
}

.page-about .stage::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--line);
  transition: background-color .2s ease;
}

.page-about .stage:hover {
  background: var(--panel);
}

.page-about .stage:hover::before {
  background: var(--cyan);
}

.page-about .stage:nth-child(2):hover::before {
  background: var(--orange);
}

.page-about .stage:nth-child(3):hover::before {
  background: var(--green);
}

.page-about .stage__phase {
  margin: 0 0 10px;
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--haze);
}

.page-about .stage__title {
  margin: 0 0 10px;
  font-size: 18px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--mist);
}

.page-about .stage__desc {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--haze);
}

.page-about .stage__delta {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px;
  margin: 16px 0 0;
  padding-top: 12px;
  border-top: 1px dashed var(--line);
  font-size: 13px;
  color: var(--haze);
}

.page-about .stage__delta-val {
  font-family: var(--font-mono);
  font-size: 16px;
  color: var(--gold);
  transition: color .2s ease;
}

.page-about .stage:hover .stage__delta-val {
  color: var(--cyan);
}

@media (min-width: 820px) {
  .page-about .stage-band {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

/* ---------- 合作 ---------- */
.page-about .partner-panel {
  max-width: none;
  padding: 22px 20px;
}

.page-about .partner-panel p {
  max-width: 68ch;
  margin: 0;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--haze);
}

.page-about .partner-list {
  display: grid;
  gap: 10px;
  margin: 18px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .partner-list li {
  padding-top: 10px;
  border-top: 1px solid var(--line);
  font-size: 14px;
  line-height: 1.62;
  color: var(--haze);
}

.page-about .partner-list .mono {
  display: block;
  margin-bottom: 4px;
  font-size: 15px;
  color: var(--gold);
}

@media (min-width: 760px) {
  .page-about .partner-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 14px;
  }
}

/* ---------- 收口 ---------- */
.page-about .about-next {
  padding: clamp(38px, 6vw, 72px) 0;
  border-top: 1px solid var(--line);
  background: var(--panel);
}

.page-about .about-next__title {
  margin: 0 0 20px;
  font-family: var(--font-display);
  font-size: clamp(20px, 2.9vw, 28px);
  font-weight: 800;
  line-height: 1.3;
  color: var(--mist);
}

.page-about .next-grid {
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .next-card {
  display: flex;
  flex-direction: column;
  gap: 7px;
  padding: 20px 18px;
  background: var(--ink);
  text-decoration: none;
  transition: background-color .2s ease;
}

.page-about .next-card:hover {
  background: #16263E;
}

.page-about .next-card__label {
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--cyan);
}

.page-about .next-card__title {
  font-size: 16px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--mist);
}

.page-about .next-card__desc {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.65;
  color: var(--haze);
}

@media (min-width: 640px) {
  .page-about .next-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 1000px) {
  .page-about .next-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ---------- 窄屏收尾 ---------- */
@media (max-width: 420px) {
  .page-about .about-facts {
    grid-template-columns: minmax(0, 1fr);
  }

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