.page-about {
  --about-line-light: rgba(11, 14, 20, 0.12);
  --about-line-dark: rgba(198, 206, 219, 0.2);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  background: var(--c-space);
  color: var(--c-paper);
  padding: calc(var(--topbar-h) + clamp(2rem, 5vw, 4rem)) 0 clamp(2.5rem, 6vw, 4.5rem);
}

.page-about .about-hero__bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.45;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  background:
    linear-gradient(180deg, rgba(16, 20, 28, 0.94) 0%, rgba(16, 20, 28, 0.66) 40%, rgba(16, 20, 28, 0.97) 100%),
    linear-gradient(118deg, rgba(22, 87, 214, 0.26) 0%, rgba(53, 224, 208, 0.12) 52%, rgba(255, 106, 31, 0.14) 100%);
}

.page-about .about-hero__inner {
  position: relative;
  z-index: 2;
}

.page-about .about-hero .breadcrumbs a {
  color: var(--c-silver);
}

.page-about .about-hero .breadcrumbs [aria-current="page"] {
  color: var(--c-paper);
}

.page-about .about-hero .eyebrow {
  margin-top: clamp(1.25rem, 3vw, 2rem);
  color: var(--c-cyan);
}

.page-about .about-hero h1 {
  margin: 0.6rem 0 0;
  max-width: 26ch;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(1.85rem, 4.4vw, 3.2rem);
  line-height: 1.2;
  letter-spacing: 0.02em;
  color: var(--c-paper);
}

.page-about .about-hero .lede {
  margin: clamp(1rem, 2.5vw, 1.5rem) 0 0;
  max-width: 64ch;
  font-size: clamp(1rem, 1.35vw, 1.1rem);
  line-height: 1.85;
  color: rgba(246, 248, 252, 0.82);
}

.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: clamp(1rem, 2.4vw, 2rem);
  margin-top: clamp(1.75rem, 4vw, 2.75rem);
  padding-top: clamp(1.25rem, 3vw, 1.75rem);
  border-top: 1px solid var(--about-line-dark);
}

.page-about .about-hero__stat {
  padding-left: 0.85rem;
  border-left: 2px solid var(--c-orange);
}

.page-about .about-hero__stat:nth-child(2) {
  border-left-color: var(--c-cyan);
}

.page-about .about-hero__stat:nth-child(3) {
  border-left-color: var(--c-blue);
}

.page-about .about-hero__stat:nth-child(4) {
  border-left-color: var(--c-silver);
}

.page-about .about-hero__num {
  display: block;
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: clamp(1.5rem, 3.2vw, 2.2rem);
  line-height: 1.1;
  color: var(--c-paper);
}

.page-about .about-hero__label {
  display: block;
  margin-top: 0.35rem;
  font-size: 0.88rem;
  color: var(--c-silver);
}

/* ---------- 产品主线 ---------- */
.page-about .about-lines {
  background: var(--c-paper);
  color: var(--c-ink);
  padding: clamp(2.75rem, 6vw, 5rem) 0;
}

.page-about .about-lines__head {
  max-width: 72ch;
}

.page-about .about-lines__head h2 {
  margin: 0.5rem 0 0;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(1.4rem, 2.7vw, 2.05rem);
  line-height: 1.3;
  letter-spacing: 0.02em;
}

.page-about .about-lines__intro {
  margin: 0.9rem 0 0;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--c-muted);
}

.page-about .about-lines__list {
  list-style: none;
  margin: clamp(1.75rem, 4vw, 2.75rem) 0 0;
  padding: 0;
  border-top: 1px solid var(--about-line-light);
}

.page-about .about-lines__list > li {
  display: grid;
  grid-template-columns: 2.4rem minmax(0, 1fr);
  gap: 0.3rem 0.9rem;
  padding: clamp(1.05rem, 2.4vw, 1.6rem) 0;
  border-bottom: 1px solid var(--about-line-light);
}

.page-about .about-lines__idx {
  grid-row: span 2;
  padding-top: 0.2rem;
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 0.85rem;
  letter-spacing: 0.04em;
  color: var(--c-orange);
}

.page-about .about-lines__title {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 1.06rem;
  letter-spacing: 0.01em;
}

.page-about .about-lines__desc {
  margin: 0.35rem 0 0;
  max-width: 74ch;
  font-size: 0.96rem;
  line-height: 1.8;
  color: var(--c-muted);
}

/* ---------- 发展沿革 ---------- */
.page-about .about-history {
  position: relative;
  background: var(--c-space);
  color: var(--c-paper);
  padding: clamp(2.75rem, 6vw, 5rem) 0;
}

.page-about .about-history::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(to right, rgba(198, 206, 219, 0.055) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(198, 206, 219, 0.055) 1px, transparent 1px);
  background-size: 48px 48px;
}

.page-about .about-history > .shell {
  position: relative;
  z-index: 1;
}

.page-about .about-history__head {
  max-width: 70ch;
}

.page-about .about-history__head .eyebrow {
  color: var(--c-cyan);
}

.page-about .about-history__head h2 {
  margin: 0.5rem 0 0;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(1.4rem, 2.7vw, 2.05rem);
  line-height: 1.3;
  letter-spacing: 0.02em;
  color: var(--c-paper);
}

.page-about .about-history__intro {
  margin: 0.85rem 0 0;
  font-size: 0.98rem;
  line-height: 1.8;
  color: rgba(246, 248, 252, 0.7);
}

.page-about .about-timeline {
  list-style: none;
  margin: clamp(1.5rem, 4vw, 2.5rem) 0 0;
  padding: 0;
  border-bottom: 1px solid var(--about-line-dark);
}

.page-about .about-timeline__item {
  display: grid;
  grid-template-columns: 4.2rem minmax(0, 1fr);
  gap: 0.4rem clamp(0.75rem, 2vw, 1.5rem);
  padding: clamp(1rem, 2.4vw, 1.5rem) 0;
  border-top: 1px solid var(--about-line-dark);
}

.page-about .about-timeline__item:nth-child(1) { --i: 0; }
.page-about .about-timeline__item:nth-child(2) { --i: 1; }
.page-about .about-timeline__item:nth-child(3) { --i: 2; }
.page-about .about-timeline__item:nth-child(4) { --i: 3; }
.page-about .about-timeline__item:nth-child(5) { --i: 4; }
.page-about .about-timeline__item:nth-child(6) { --i: 5; }
.page-about .about-timeline__item:nth-child(7) { --i: 6; }

.page-about .about-timeline__year {
  padding-top: 0.1rem;
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 0.92rem;
  letter-spacing: 0.05em;
  color: var(--c-cyan);
}

.page-about .about-timeline__body h3 {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 1.04rem;
  letter-spacing: 0.01em;
  color: var(--c-paper);
}

.page-about .about-timeline__body p {
  margin: 0.4rem 0 0;
  max-width: 68ch;
  font-size: 0.94rem;
  line-height: 1.8;
  color: rgba(246, 248, 252, 0.7);
}

.page-about .about-history__media {
  margin: clamp(1.75rem, 4vw, 2.75rem) 0 0;
  border: 1px solid var(--about-line-dark);
  background: rgba(11, 14, 20, 0.6);
  overflow: hidden;
}

.page-about .about-history__media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  opacity: 0.86;
}

.page-about .about-history__media figcaption {
  padding: 0.7rem 0.9rem;
  border-top: 1px solid var(--about-line-dark);
  font-size: 0.82rem;
  line-height: 1.6;
  color: var(--c-silver);
}

/* ---------- 主体结构 ---------- */
.page-about .about-structure {
  background: var(--c-paper);
  color: var(--c-ink);
  padding: clamp(2.75rem, 6vw, 5rem) 0;
}

.page-about .about-structure__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.75rem, 4vw, 3rem);
}

.page-about .about-index {
  background: var(--c-indy);
  color: var(--c-paper);
  padding: clamp(1.15rem, 3vw, 1.6rem);
}

.page-about .about-index__title {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 0.92rem;
  letter-spacing: 0.1em;
  color: var(--c-cyan);
}

.page-about .about-index__levels {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.3rem;
  margin: 0.9rem 0 0;
  padding: 0;
}

.page-about .about-index__level {
  padding: 0.22rem 0.44rem;
  border: 1px solid rgba(198, 206, 219, 0.32);
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 0.75rem;
  letter-spacing: 0.03em;
  color: var(--c-silver);
}

.page-about .about-index__note {
  margin: 0.95rem 0 0;
  font-size: 0.82rem;
  line-height: 1.7;
  color: rgba(246, 248, 252, 0.68);
}

.page-about .about-index__nav {
  display: flex;
  flex-direction: column;
  margin-top: 1.15rem;
  border-top: 1px solid rgba(198, 206, 219, 0.22);
}

.page-about .about-index__nav a {
  padding: 0.62rem 0;
  border-bottom: 1px solid rgba(198, 206, 219, 0.16);
  font-size: 0.88rem;
  color: var(--c-paper);
  text-decoration: none;
  transition: color 0.25s var(--ease), padding-left 0.25s var(--ease);
}

.page-about .about-index__nav a:hover,
.page-about .about-index__nav a:focus-visible {
  padding-left: 0.3rem;
  color: var(--c-cyan);
}

.page-about .about-block {
  scroll-margin-top: calc(var(--topbar-h) + 1.5rem);
}

.page-about .about-block + .about-block {
  margin-top: clamp(2rem, 4.5vw, 3.25rem);
  padding-top: clamp(2rem, 4.5vw, 3.25rem);
  border-top: 1px solid var(--about-line-light);
}

.page-about .about-block h2 {
  margin: 0.5rem 0 0;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(1.3rem, 2.5vw, 1.8rem);
  line-height: 1.32;
  letter-spacing: 0.02em;
}

.page-about .about-block > p {
  margin: 0.85rem 0 0;
  max-width: 76ch;
  font-size: 0.98rem;
  line-height: 1.85;
  color: var(--c-ink);
}

/* 授权四条件 */
.page-about .about-facts {
  margin: 1.3rem 0 0;
  padding: 0;
  border-top: 1px solid var(--about-line-light);
}

.page-about .about-facts__row {
  display: grid;
  gap: 0.25rem;
  padding: 0.85rem 0;
  border-bottom: 1px solid var(--about-line-light);
}

.page-about .about-facts dt {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 0.95rem;
  letter-spacing: 0.01em;
}

.page-about .about-facts dd {
  margin: 0;
  font-size: 0.94rem;
  line-height: 1.75;
  color: var(--c-muted);
}

/* 价格档位 */
.page-about .tier-list {
  list-style: none;
  display: grid;
  gap: 1px;
  margin: 1.35rem 0 0;
  padding: 0;
  background: var(--about-line-light);
  border: 1px solid var(--about-line-light);
}

.page-about .tier-list > li {
  background: var(--c-paper);
  padding: clamp(0.95rem, 2.2vw, 1.3rem);
}

.page-about .tier-list__tag {
  display: inline-block;
  padding: 0.2rem 0.55rem;
  border: 1px solid var(--c-blue);
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 0.78rem;
  letter-spacing: 0.05em;
  color: var(--c-blue);
}

.page-about .tier-list__tag--accent {
  border-color: var(--c-orange);
  color: var(--c-orange);
}

.page-about .tier-list__tag--cyan {
  border-color: var(--c-teal);
  color: var(--c-teal);
}

.page-about .tier-list > li p {
  margin: 0.6rem 0 0;
  font-size: 0.93rem;
  line-height: 1.75;
  color: var(--c-muted);
}

/* 媒体图 */
.page-about .about-media {
  margin: clamp(1.35rem, 3vw, 2rem) 0 0;
  border: 1px solid var(--about-line-light);
  background: var(--c-space);
  overflow: hidden;
}

.page-about .about-media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
}

.page-about .about-media figcaption {
  padding: 0.7rem 0.9rem;
  border-top: 1px solid var(--about-line-dark);
  font-size: 0.82rem;
  line-height: 1.6;
  color: var(--c-silver);
}

/* 专利年度柱状 */
.page-about .about-bars {
  list-style: none;
  display: flex;
  gap: clamp(0.4rem, 1.6vw, 0.9rem);
  margin: 1.5rem 0 0;
  padding: 0;
}

.page-about .about-bars__item {
  flex: 1 1 0;
  min-width: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.4rem;
}

.page-about .about-bars__val {
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 0.85rem;
  color: var(--c-ink);
}

.page-about .about-bars__track {
  display: flex;
  align-items: flex-end;
  width: 100%;
  height: 110px;
  background: rgba(198, 206, 219, 0.18);
}

.page-about .about-bars__fill {
  display: block;
  width: 100%;
  background: linear-gradient(180deg, var(--c-cyan) 0%, var(--c-blue) 100%);
  transition: height 0.6s var(--ease);
}

.page-about .about-bars__item:nth-child(1) .about-bars__fill { height: 21.4%; }
.page-about .about-bars__item:nth-child(2) .about-bars__fill { height: 33.3%; }
.page-about .about-bars__item:nth-child(3) .about-bars__fill { height: 45.2%; }
.page-about .about-bars__item:nth-child(4) .about-bars__fill { height: 61.9%; }
.page-about .about-bars__item:nth-child(5) .about-bars__fill { height: 78.6%; }
.page-about .about-bars__item:nth-child(6) .about-bars__fill { height: 100%; }

.page-about .about-bars__year {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--c-muted);
}

.page-about .about-bars__cap {
  margin: 0.65rem 0 0;
  font-size: 0.82rem;
  line-height: 1.6;
  color: var(--c-muted);
}

/* ---------- 结尾行动区 ---------- */
.page-about .about-cta {
  background: var(--c-teal);
  color: var(--c-paper);
  padding: clamp(2.25rem, 5vw, 3.5rem) 0;
}

.page-about .about-cta__inner {
  display: grid;
  gap: 1.5rem;
  align-items: center;
}

.page-about .about-cta h2 {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(1.25rem, 2.4vw, 1.7rem);
  line-height: 1.32;
  letter-spacing: 0.02em;
  color: var(--c-paper);
}

.page-about .about-cta p {
  margin: 0.6rem 0 0;
  max-width: 58ch;
  font-size: 0.97rem;
  line-height: 1.8;
  color: rgba(246, 248, 252, 0.84);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.page-about .about-cta__actions .btn--ghost {
  border-color: rgba(246, 248, 252, 0.5);
  background: transparent;
  color: var(--c-paper);
}

.page-about .about-cta__actions .btn--ghost:hover,
.page-about .about-cta__actions .btn--ghost:focus-visible {
  border-color: var(--c-cyan);
  color: var(--c-cyan);
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-facts__row {
    grid-template-columns: 9rem minmax(0, 1fr);
    gap: 1rem;
    align-items: baseline;
  }

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

@media (min-width: 720px) {
  .page-about .about-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-timeline__item {
    grid-template-columns: 4.6rem minmax(0, 1fr);
    padding-left: calc(var(--i, 0) * 1.1rem);
  }
}

@media (min-width: 860px) {
  .page-about .about-cta__inner {
    grid-template-columns: minmax(0, 1.5fr) auto;
    gap: 2.5rem;
  }

  .page-about .about-cta__actions {
    justify-content: flex-end;
  }
}

@media (min-width: 960px) {
  .page-about .about-structure__grid {
    grid-template-columns: 252px minmax(0, 1fr);
    gap: clamp(2rem, 4vw, 3.5rem);
    align-items: start;
  }

  .page-about .about-index {
    position: sticky;
    top: calc(var(--topbar-h) + 1.5rem);
  }

  .page-about .about-timeline__item {
    padding-left: calc(var(--i, 0) * 1.5rem);
  }
}

@media (max-width: 480px) {
  .page-about .about-hero__stats {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-timeline__item {
    grid-template-columns: minmax(0, 1fr);
    gap: 0.3rem;
  }

  .page-about .about-bars__track {
    height: 84px;
  }

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

  .page-about .about-lines__idx {
    grid-row: auto;
    padding-top: 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-bars__fill,
  .page-about .about-index__nav a {
    transition: none;
  }
}