.page-about {
  --story-accent-soft: rgba(57, 255, 20, 0.08);
  --story-warn-soft: rgba(176, 0, 32, 0.1);
  --story-grid-size: 44px;
  background: var(--bg-main);
  color: var(--text-main);
  font-family: var(--font-body);
  overflow-x: hidden;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: 48px 0 56px;
  border-bottom: 1px solid var(--border);
  background:
    linear-gradient(rgba(255, 255, 255, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.03) 1px, transparent 1px);
  background-size: var(--story-grid-size) var(--story-grid-size);
}
.page-about .about-hero::before {
  content: "";
  position: absolute;
  right: -120px;
  top: -120px;
  width: 360px;
  height: 360px;
  background: radial-gradient(circle, var(--story-accent-soft) 0%, transparent 70%);
  pointer-events: none;
}
.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
}
.page-about .about-hero__grid {
  display: grid;
  gap: 40px;
  margin-top: 36px;
}
.page-about .about-hero__kicker {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--text-secondary);
  border-left: 2px solid var(--warn);
  padding-left: 12px;
  margin-bottom: 16px;
}
.page-about .about-hero__title {
  font-family: var(--font-head);
  font-size: clamp(2.2rem, 6vw, 4rem);
  font-weight: 300;
  line-height: 1.15;
  margin: 0 0 24px;
}
.page-about .about-hero__title .title-sub {
  display: block;
  font-size: 0.72em;
  font-weight: 300;
  color: var(--text-secondary);
  margin-top: 0.25em;
}
.page-about .about-hero__lead {
  font-size: 1rem;
  line-height: 1.8;
  color: var(--text-secondary);
  max-width: 54ch;
  margin: 0 0 28px;
}
.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}
.page-about .about-hero__panel {
  position: relative;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  padding: 20px;
}
.page-about .about-hero__panel::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--gradient);
}
.page-about .about-hero__panel-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px;
}
.page-about .about-hero__panel-id {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  color: var(--text-dim);
}
.page-about .about-hero__stats {
  margin: 0;
}
.page-about .about-hero__stat {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 16px;
  padding: 14px 2px;
  border-bottom: 1px dashed var(--border);
}
.page-about .about-hero__stat:last-child {
  border-bottom: 0;
}
.page-about .about-hero__stat dt {
  font-size: 0.875rem;
  color: var(--text-secondary);
}
.page-about .about-hero__stat dd {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  color: var(--text-main);
}
.page-about .about-hero__note {
  margin: 16px 0 0;
  font-size: 0.875rem;
  line-height: 1.6;
  color: var(--text-secondary);
  border-left: 2px solid var(--warn);
  padding-left: 12px;
}
.page-about .about-hero__stamp {
  display: inline-block;
  margin-top: 16px;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  letter-spacing: 0.1em;
  color: var(--warn);
  border: 1px solid var(--warn);
  padding: 4px 10px;
  transform: rotate(-2deg);
}

/* ---------- 章节导航 ---------- */
.page-about .about-chapter-nav {
  position: sticky;
  top: 0;
  z-index: 40;
  background: rgba(20, 20, 20, 0.92);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(10px);
}
.page-about .about-chapter-nav__inner {
  display: flex;
  gap: 4px;
  overflow-x: auto;
  padding: 0 20px;
}
.page-about .about-chapter-nav__item {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 14px 16px;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--text-secondary);
  text-decoration: none;
  border-bottom: 2px solid transparent;
  white-space: nowrap;
  transition: color 0.2s, border-color 0.2s;
}
.page-about .about-chapter-nav__item:hover {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

/* ---------- 章节通用头 ---------- */
.page-about .about-sec-head {
  margin-bottom: 40px;
  padding-left: 20px;
  border-left: 3px solid var(--accent);
}
.page-about .about-sec-index {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  letter-spacing: 0.15em;
  color: var(--accent);
  margin-bottom: 8px;
}
.page-about .about-sec-title {
  font-family: var(--font-head);
  font-size: clamp(1.6rem, 3vw, 2.4rem);
  font-weight: 700;
  margin: 0;
}
.page-about .about-sec-desc {
  margin: 10px 0 0;
  color: var(--text-secondary);
}

/* ---------- 01 品牌起源 ---------- */
.page-about .about-why {
  padding: 64px 0;
}
.page-about .about-why__grid {
  display: grid;
  gap: 32px;
}
.page-about .about-why__content {
  color: var(--text-secondary);
  line-height: 1.8;
}
.page-about .about-why__content p {
  margin: 0 0 18px;
}
.page-about .about-why__content strong {
  color: var(--text-main);
}
.page-about .about-why__lead {
  color: var(--text-main);
  font-size: 1.05rem;
}
.page-about .about-why__link {
  margin-top: 24px;
}
.page-about .about-why__figure {
  position: relative;
  margin: 0;
}
.page-about .about-why__figure::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: repeating-linear-gradient(0deg, rgba(57, 255, 20, 0.04) 0px, rgba(57, 255, 20, 0.04) 1px, transparent 1px, transparent 3px);
}
.page-about .about-why__figure img {
  width: 100%;
  height: auto;
  display: block;
  border: 1px solid var(--border);
}

/* ---------- 02 发展里程碑 ---------- */
.page-about .about-milestones {
  padding: 64px 0;
  background: var(--bg-secondary);
}
.page-about .about-milestones .about-sec-head {
  border-left-color: var(--warn);
}
.page-about .about-milestones .about-sec-index {
  color: var(--warn);
}
.page-about .about-milestones__layout {
  display: grid;
  gap: 40px;
}
.page-about .about-milestones__intro {
  align-self: start;
}
.page-about .about-milestones__intro > p {
  margin: 0 0 24px;
  color: var(--text-secondary);
  line-height: 1.8;
}
.page-about .about-milestones__intro-note {
  border: 1px solid var(--border);
  border-left: 3px solid var(--warn);
  background: var(--bg-panel);
  padding: 16px;
}
.page-about .about-milestones__intro-note p {
  margin: 12px 0 0;
  font-size: 0.875rem;
  line-height: 1.7;
  color: var(--text-secondary);
}
.page-about .about-milestones__timeline {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0;
}
.page-about .about-milestones__timeline::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 10px;
  bottom: 10px;
  width: 2px;
  background: linear-gradient(180deg, var(--accent), var(--warn));
  opacity: 0.4;
}
.page-about .about-milestones .timeline__item {
  position: relative;
  padding: 0 0 36px 32px;
}
.page-about .about-milestones .timeline__item:last-child {
  padding-bottom: 0;
}
.page-about .about-milestones .timeline__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 6px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--bg-main);
  border: 3px solid var(--accent);
  box-shadow: 0 0 0 4px var(--story-accent-soft);
}
.page-about .about-milestones .timeline__item:nth-child(even)::before {
  border-color: var(--warn);
  box-shadow: 0 0 0 4px var(--story-warn-soft);
}
.page-about .about-milestones .timeline__date {
  display: block;
  margin-bottom: 14px;
  font-family: var(--font-mono);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--accent);
}
.page-about .about-milestones .timeline__item:nth-child(even) .timeline__date {
  color: var(--warn);
}
.page-about .about-milestones .timeline__body {
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.02);
  padding: 18px 20px;
  transition: border-color 0.25s;
}
.page-about .about-milestones .timeline__item:hover .timeline__body {
  border-color: var(--accent);
}
.page-about .about-milestones .timeline__title {
  font-family: var(--font-head);
  font-size: 1.15rem;
  font-weight: 700;
  margin: 0 0 8px;
}
.page-about .about-milestones .timeline__body p {
  margin: 0 0 12px;
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--text-secondary);
}
.page-about .about-milestones .timeline__meta {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-dim);
}

/* ---------- 03 数据能力 ---------- */
.page-about .about-data {
  padding: 64px 0;
}
.page-about .about-data__grid {
  display: grid;
  gap: 32px;
  margin-bottom: 32px;
}
.page-about .about-data__stats {
  display: grid;
  gap: 12px;
}
.page-about .about-data__stat {
  background: var(--bg-panel);
  border: 1px solid var(--border);
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.page-about .about-data__number {
  font-family: var(--font-mono);
  font-size: 2rem;
  font-weight: 700;
  line-height: 1.2;
  background: var(--gradient);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.page-about .about-data__label {
  font-size: 0.875rem;
  color: var(--text-secondary);
}
.page-about .about-data__content {
  color: var(--text-secondary);
  line-height: 1.8;
}
.page-about .about-data__content p {
  margin: 0 0 16px;
}
.page-about .about-data__list {
  margin: 0 0 20px;
  padding-left: 18px;
}
.page-about .about-data__list li {
  margin-bottom: 10px;
}
.page-about .about-data__more {
  font-family: var(--font-mono);
  font-size: 0.875rem;
}
.page-about .about-data__more a {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid transparent;
}
.page-about .about-data__more a:hover {
  border-bottom-color: var(--accent);
}
.page-about .about-data__figure {
  position: relative;
  margin: 0 0 24px;
}
.page-about .about-data__figure::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: repeating-linear-gradient(0deg, rgba(255, 255, 255, 0.015) 0px, rgba(255, 255, 255, 0.015) 1px, transparent 1px, transparent 3px);
}
.page-about .about-data__figure img {
  width: 100%;
  height: auto;
  display: block;
  border: 1px solid var(--border);
}
.page-about .about-data__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

/* ---------- 04 服务承诺 ---------- */
.page-about .about-commit {
  padding: 64px 0;
  background: var(--bg-secondary);
}
.page-about .about-commit .about-sec-head {
  border-left-color: var(--warn);
}
.page-about .about-commit .about-sec-index {
  color: var(--warn);
}
.page-about .about-commit__grid {
  display: grid;
  gap: 32px;
}
.page-about .about-commit__cards {
  display: grid;
  gap: 16px;
}
.page-about .about-commit__card {
  position: relative;
  border: 1px solid var(--border);
  background: var(--bg-panel);
  padding: 24px 24px 20px;
  border-top: 3px solid var(--accent);
  margin: 0;
  transition: border-color 0.25s;
}
.page-about .about-commit__card:hover {
  border-color: var(--accent);
}
.page-about .about-commit__card--warn {
  border-top-color: var(--warn);
}
.page-about .about-commit__card--warn:hover {
  border-color: var(--warn);
}
.page-about .about-commit__card-index {
  position: absolute;
  top: 18px;
  right: 20px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-dim);
}
.page-about .about-commit__card .card__title {
  font-size: 1.1rem;
  margin-bottom: 10px;
  padding-right: 60px;
}
.page-about .about-commit__card .card__text {
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 12px;
}
.page-about .about-commit__card .card__meta {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  color: var(--text-dim);
}
.page-about .about-commit__figure {
  margin: 0;
}
.page-about .about-commit__figure img {
  width: 100%;
  height: auto;
  display: block;
  border: 1px solid var(--border);
}
.page-about .about-commit__footer {
  margin-top: 48px;
  padding-top: 32px;
  border-top: 1px solid var(--border);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}
.page-about .about-commit__footer p {
  margin: 0;
  max-width: 60ch;
  color: var(--text-secondary);
  line-height: 1.7;
}
.page-about .about-commit__footer a {
  color: var(--accent);
}

/* ---------- 桌面端 ---------- */
@media (min-width: 900px) {
  .page-about .about-hero {
    padding: 72px 0 96px;
  }
  .page-about .about-hero__grid {
    grid-template-columns: 1.2fr 0.8fr;
    gap: 80px;
    align-items: center;
  }
  .page-about .about-why,
  .page-about .about-milestones,
  .page-about .about-data,
  .page-about .about-commit {
    padding: 96px 0;
  }
  .page-about .about-why__grid {
    grid-template-columns: 1fr 1fr;
    gap: 72px;
    align-items: center;
  }
  .page-about .about-milestones__layout {
    grid-template-columns: 0.85fr 1.15fr;
    gap: 80px;
  }
  .page-about .about-milestones__intro {
    position: sticky;
    top: 84px;
  }
  .page-about .about-data__grid {
    grid-template-columns: 0.9fr 1.1fr;
    gap: 60px;
    margin-bottom: 40px;
  }
  .page-about .about-data__stats {
    grid-template-columns: 1fr;
    align-content: start;
  }
  .page-about .about-data__stat {
    padding: 28px;
  }
  .page-about .about-commit__grid {
    grid-template-columns: 1.2fr 0.8fr;
    gap: 64px;
    align-items: start;
  }
  .page-about .about-commit__cards {
    grid-template-columns: 1fr 1fr;
    gap: 20px;
  }
}