.page-about {
  --about-paper-dim: rgba(245, 239, 230, 0.74);
  --about-gold-line: linear-gradient(108deg, transparent 45%, var(--gold) 46%, var(--gold) 53%, transparent 54%);
}

/* ===================== 品牌声明区 ===================== */
.page-about__intro {
  position: relative;
  overflow: hidden;
  background: var(--paper);
}

.page-about__intro-grid {
  display: grid;
  gap: 2rem;
}

.page-about__intro-copy .eyebrow {
  color: var(--gold-deep);
}

.page-about__intro-copy h1 {
  font-family: var(--font-serif);
  font-size: clamp(2.2rem, 6vw, 4.8rem);
  line-height: 1.08;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin: 0.75rem 0 1.5rem;
  color: var(--ink);
}

.page-about__lead {
  font-size: 1.25rem;
  line-height: 1.75;
  color: var(--ink);
  border-left: 4px solid var(--gold);
  padding-left: 1.25rem;
  margin-bottom: 1.25rem;
}

.page-about__intro-text {
  color: var(--ink-mid);
  line-height: 1.75;
  margin-bottom: 1rem;
}

.page-about__intro-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1.5rem;
}

.page-about__intro-figure {
  margin: 0;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  transform: rotate(1.2deg) translateX(4px);
}

.page-about__intro-figure img {
  width: 100%;
  height: auto;
  display: block;
}

/* ===================== 斜向分隔带 ===================== */
.page-about__divider {
  height: 44px;
  background: var(--about-gold-line);
}

/* ===================== 发展历程 ===================== */
.page-about__journey {
  background-color: var(--deep);
  color: var(--paper-light);
}

.page-about__journey .eyebrow,
.page-about__scale .eyebrow {
  color: var(--gold);
}

.page-about__journey .section-title,
.page-about__scale .section-title {
  color: var(--paper-light);
}

.page-about__journey .section-intro,
.page-about__scale .section-intro {
  color: var(--about-paper-dim);
}

.page-about__journey-top {
  display: grid;
  gap: 1.5rem;
}

.page-about__journey-figure {
  margin: 0;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid rgba(245, 239, 230, 0.14);
}

.page-about__journey-figure img {
  width: 100%;
  height: auto;
  display: block;
}

.page-about__tl-filter {
  margin-top: 2.5rem;
  flex-wrap: wrap;
}

.page-about__tl-filter .filter-btn {
  color: var(--paper-light);
  background: transparent;
  border-color: rgba(245, 239, 230, 0.3);
}

.page-about__tl-filter .filter-btn.is-active {
  background: var(--gold);
  border-color: var(--gold);
  color: var(--ink);
}

.page-about__timeline {
  margin-top: 2.5rem;
}

.page-about__tl-item {
  display: grid;
  grid-template-columns: 52px 16px 1fr;
  gap: 0.75rem;
  padding-bottom: 2.25rem;
}

.page-about__tl-year {
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--gold);
  text-align: right;
  padding-top: 0.25rem;
}

.page-about__tl-line {
  position: relative;
}

.page-about__tl-line::before {
  content: "";
  position: absolute;
  left: 50%;
  top: 8px;
  bottom: -14px;
  width: 2px;
  transform: translateX(-50%);
  background: linear-gradient(180deg, var(--gold) 0%, rgba(195, 150, 61, 0.18) 100%);
}

.page-about__tl-item:last-child .page-about__tl-line::before {
  display: none;
}

.page-about__tl-line::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 4px;
  width: 10px;
  height: 10px;
  transform: translateX(-50%);
  background: var(--gold);
  border: 3px solid var(--deep);
  border-radius: 50%;
  box-shadow: 0 0 0 1px rgba(195, 150, 61, 0.45);
}

.page-about__tl-card {
  background: rgba(245, 239, 230, 0.05);
  border: 1px solid rgba(245, 239, 230, 0.12);
  border-radius: var(--radius-md);
  padding: 1.25rem;
}

.page-about__tl-card h3 {
  font-family: var(--font-serif);
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--paper-light);
  margin: 0 0 0.6rem;
}

.page-about__tl-card p {
  color: var(--about-paper-dim);
  font-size: 0.95rem;
  line-height: 1.7;
  margin: 0;
}

/* ===================== 内容体系 ===================== */
.page-about__system {
  background: var(--paper);
}

.page-about__system-filter {
  margin-top: 2rem;
  flex-wrap: wrap;
}

.page-about__system-grid {
  display: grid;
  gap: 1.5rem;
  margin-top: 2rem;
}

.page-about__system-card {
  position: relative;
  overflow: hidden;
  padding: 1.75rem;
  background: var(--paper-light);
  border: 1px solid rgba(26, 29, 32, 0.06);
  border-radius: var(--radius-lg);
  transition: transform 240ms ease, box-shadow 240ms ease;
}

.page-about__system-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.page-about__system-card::after {
  content: "";
  position: absolute;
  top: 0;
  left: -35%;
  width: 30%;
  height: 100%;
  background: linear-gradient(100deg, transparent, rgba(195, 150, 61, 0.3), transparent);
  transform: skewX(-15deg);
  transition: left 420ms ease-out;
}

.page-about__system-card:hover::after {
  left: 120%;
}

.page-about__system-num {
  width: 46px;
  height: 46px;
  border-radius: 14px;
  background: var(--crimson);
  color: var(--paper-light);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 1.2rem;
  margin-bottom: 1rem;
}

.page-about__system-card h3 {
  font-family: var(--font-serif);
  font-size: 1.5rem;
  color: var(--ink);
  margin: 0 0 0.75rem;
}

.page-about__system-card > p {
  color: var(--ink-mid);
  font-size: 0.95rem;
  line-height: 1.7;
  margin-bottom: 1rem;
}

.page-about__system-card ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.page-about__system-card li {
  font-size: 0.82rem;
  color: var(--crimson);
  background: rgba(127, 45, 51, 0.08);
  border-radius: var(--radius-pill);
  padding: 0.3rem 0.8rem;
}

.page-about__system-note {
  margin-top: 2rem;
  padding: 1rem 1.25rem;
  background: var(--brick);
  border-radius: var(--radius-md);
  color: var(--paper-light);
  font-size: 0.95rem;
  line-height: 1.6;
}

.page-about__system-note p {
  margin: 0;
}

/* ===================== 数据与规模 ===================== */
.page-about__scale {
  background-color: var(--deep);
  color: var(--paper-light);
}

.page-about__scale-grid {
  display: grid;
  gap: 2.5rem;
}

.page-about__scale-head {
  margin-bottom: 0;
}

.page-about__scale-stats {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
}

.page-about__stat {
  background: rgba(245, 239, 230, 0.06);
  border: 1px solid rgba(195, 150, 61, 0.28);
  border-radius: var(--radius-md);
  padding: 1.25rem;
}

.page-about__stat .data-card__value {
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: clamp(2.4rem, 6vw, 4rem);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--gold);
  margin-bottom: 0.4rem;
}

.page-about__stat .data-card__label {
  color: var(--paper-light);
  font-size: 0.92rem;
  margin-bottom: 0.3rem;
}

.page-about__stat .data-card__foot {
  color: var(--about-paper-dim);
  font-size: 0.82rem;
}

.page-about__scale-figure {
  margin: 2.5rem 0 0;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid rgba(245, 239, 230, 0.12);
}

.page-about__scale-figure img {
  width: 100%;
  height: auto;
  display: block;
}

/* ===================== 团队与生态 ===================== */
.page-about__team {
  background-color: var(--crimson);
  color: var(--paper-light);
}

.page-about__team .eyebrow {
  color: var(--gold);
}

.page-about__team .section-title {
  color: var(--paper-light);
}

.page-about__team .section-intro {
  color: var(--about-paper-dim);
}

.page-about__team-grid {
  display: grid;
  gap: 1.5rem;
  margin-top: 2rem;
}

.page-about__team-card {
  background: var(--paper-light);
  color: var(--ink);
  border-radius: var(--radius-lg);
  padding: 2rem;
  position: relative;
  overflow: hidden;
}

.page-about__team-card h3 {
  font-family: var(--font-serif);
  font-size: 1.5rem;
  color: var(--ink);
  margin: 0 0 1rem;
}

.page-about__team-num {
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 4rem;
  line-height: 1;
  color: var(--crimson);
  margin-bottom: 0.35rem;
}

.page-about__team-unit {
  color: var(--ink-mid);
  font-size: 0.95rem;
  margin-bottom: 1rem;
}

.page-about__team-card > p {
  color: var(--ink-mid);
  font-size: 0.95rem;
  line-height: 1.7;
  margin-bottom: 1rem;
}

.page-about__team-card ul {
  list-style: none;
  padding: 0;
  margin: 0;
  border-top: 1px solid rgba(26, 29, 32, 0.08);
  padding-top: 1rem;
}

.page-about__team-card li {
  position: relative;
  color: var(--ink-mid);
  font-size: 0.9rem;
  line-height: 1.6;
  padding-left: 1rem;
}

.page-about__team-card li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.6em;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--gold);
}

.page-about__team-card li + li {
  margin-top: 0.35rem;
}

/* ===================== 入口链接 ===================== */
.page-about__links {
  background: var(--paper);
}

.page-about__links-band {
  display: grid;
  gap: 1.75rem;
  background: var(--indigo);
  border-radius: var(--radius-lg);
  padding: 2rem;
  color: var(--paper-light);
}

.page-about__links-copy h2 {
  font-family: var(--font-serif);
  font-size: 1.75rem;
  color: var(--paper-light);
  margin: 0 0 0.6rem;
}

.page-about__links-copy p {
  color: var(--about-paper-dim);
  line-height: 1.6;
  margin: 0;
}

.page-about__links-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.page-about__links-list a {
  color: var(--paper-light);
  text-decoration: none;
  border: 1px solid rgba(245, 239, 230, 0.32);
  border-radius: var(--radius-pill);
  padding: 0.65rem 1.25rem;
  font-size: 0.95rem;
  transition: background 240ms ease, color 240ms ease, border-color 240ms ease;
}

.page-about__links-list a:hover {
  background: var(--gold);
  border-color: var(--gold);
  color: var(--ink);
}

/* ===================== 桌面端布局 ===================== */
@media (min-width: 960px) {
  .page-about__intro-grid {
    grid-template-columns: 1.1fr 0.9fr;
    gap: 4rem;
    align-items: center;
  }

  .page-about__intro-figure {
    transform: rotate(1.5deg) translateX(18px);
  }

  .page-about__journey-top {
    grid-template-columns: 1.2fr 0.8fr;
    gap: 3rem;
    align-items: center;
  }

  .page-about__journey-top .section-head {
    margin-bottom: 0;
  }

  .page-about__tl-item {
    grid-template-columns: 150px 60px 1fr;
    gap: 0 28px;
  }

  .page-about__tl-year {
    position: sticky;
    top: 100px;
    align-self: start;
    font-size: 1.6rem;
  }

  .page-about__tl-card {
    padding: 1.5rem 1.75rem;
  }

  .page-about__system-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .page-about__system-card {
    padding: 2rem;
  }

  .page-about__scale-grid {
    grid-template-columns: 0.9fr 1.4fr;
    gap: 3rem;
    align-items: stretch;
  }

  .page-about__scale-stats {
    grid-template-columns: repeat(2, 1fr);
    gap: 1.25rem;
  }

  .page-about__scale-figure {
    margin-top: 3.5rem;
  }

  .page-about__team-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 2rem;
  }

  .page-about__links-band {
    grid-template-columns: 1.15fr 0.85fr;
    align-items: center;
    gap: 2.5rem;
    padding: 2.5rem;
  }
}

@media (min-width: 1200px) {
  .page-about__scale-stats {
    grid-template-columns: repeat(4, 1fr);
  }
}