.page-about {
  --about-accent: #D32F2F;
  --about-accent-light: #FF5252;
  --about-accent-blue: #00BFFF;
  --about-deep-red: #8B0000;
  --about-cream: #F5F0E1;
  --about-bg: #1A1A1A;
  --about-text: #E0E0E0;
  --about-card-bg: #F5F0E1;
  --about-card-text: #1A1A1A;
  --about-silver: #C0C0C0;
  --about-gap: 1.5rem;
  --about-max-width: 1200px;
  background: var(--about-bg);
  color: var(--about-text);
  font-family: system-ui, sans-serif;
  line-height: 1.6;
  overflow-x: hidden;
}

/* ── 面包屑 ── */
.page-about .breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.4rem 0.6rem;
  font-size: 0.8rem;
  color: var(--about-silver);
  margin-bottom: 1.2rem;
  padding-top: 1rem;
  letter-spacing: 0.02em;
}
.page-about .breadcrumb a {
  color: var(--about-silver);
  text-decoration: none;
  transition: color 0.2s;
}
.page-about .breadcrumb a:hover {
  color: var(--about-accent-light);
}
.page-about .breadcrumb__sep {
  color: var(--about-silver);
  opacity: 0.5;
}
.page-about .breadcrumb [aria-current="page"] {
  color: var(--about-cream);
  font-weight: 600;
}

/* ── 通用容器 ── */
.page-about .container {
  max-width: var(--about-max-width);
  margin: 0 auto;
  padding: 0 1.2rem;
}

/* ── 大编号 / 小标题 ── */
.page-about .section-number {
  font-family: Futura, Impact, sans-serif;
  font-size: 3.2rem;
  font-weight: 800;
  font-style: italic;
  line-height: 1;
  color: var(--about-accent);
  display: block;
  margin-bottom: 0.15rem;
  letter-spacing: -0.02em;
}
.page-about .section-title {
  font-family: Futura, Impact, sans-serif;
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--about-cream);
  margin: 0 0 0.2rem;
  line-height: 1.2;
  text-transform: uppercase;
  letter-spacing: 0.02em;
}
.page-about .page-about__annotation {
  font-size: 0.75rem;
  writing-mode: vertical-rl;
  rotate: 180deg;
  position: absolute;
  right: -2.2rem;
  top: 0.2rem;
  color: var(--about-accent-blue);
  letter-spacing: 0.15em;
  font-weight: 600;
  opacity: 0.8;
  white-space: nowrap;
}
.page-about .page-about__section-header {
  position: relative;
  margin-bottom: 2.2rem;
  padding-right: 2.8rem;
}

/* ── 首屏 ── */
.page-about__hero {
  padding: 1rem 0 2.5rem;
  position: relative;
  background: linear-gradient(135deg, #1A1A1A 60%, #2A0A0A 100%);
  border-bottom: 2px solid var(--about-accent);
}
.page-about__hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: repeating-linear-gradient(45deg, transparent, transparent 20px, rgba(211,47,47,0.03) 20px, rgba(211,47,47,0.03) 40px);
  pointer-events: none;
}
.page-about__hero-layout {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  position: relative;
  z-index: 1;
}
.page-about__hero-brand {
  display: flex;
  align-items: center;
  gap: 1.8rem;
  flex-wrap: wrap;
}
.page-about__brand-frame {
  flex-shrink: 0;
  width: 100px;
  height: 100px;
  border-radius: 50%;
  border: 3px solid var(--about-accent);
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--about-bg);
  box-shadow: 0 0 30px rgba(211,47,47,0.25);
}
.page-about__brand-logo {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}
.page-about__hero-text {
  flex: 1;
  min-width: 200px;
}
.page-about__hero-text .section-number {
  font-size: 2.4rem;
  margin-bottom: 0.1rem;
}
.page-about__title {
  font-family: Futura, Impact, sans-serif;
  font-size: 2.2rem;
  font-weight: 800;
  font-style: italic;
  color: var(--about-cream);
  margin: 0 0 0.3rem;
  line-height: 1.1;
  text-shadow: 0 2px 12px rgba(0,0,0,0.5);
}
.page-about__subtitle {
  font-size: 1rem;
  color: var(--about-silver);
  margin: 0;
  letter-spacing: 0.04em;
}
.page-about__hero-desc {
  font-size: 1rem;
  color: var(--about-text);
  max-width: 780px;
  margin: 0;
  background: rgba(245,240,225,0.06);
  padding: 1rem 1.4rem;
  border-left: 4px solid var(--about-accent);
  border-radius: 0 8px 8px 0;
  backdrop-filter: blur(4px);
}
.page-about__hero-divider {
  height: 4px;
  background: linear-gradient(90deg, var(--about-accent), var(--about-accent-blue), transparent);
  margin-top: 2rem;
}

/* ── 通用章节 ── */
.page-about__section {
  padding: 3rem 0;
  position: relative;
  border-bottom: 1px solid rgba(192,192,192,0.08);
}
.page-about__section:last-child {
  border-bottom: none;
}

/* ── 品牌定位 ── */
.page-about__mission-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.2rem;
}
.page-about__mission-card {
  padding: 1.6rem 1.8rem;
  border-radius: 12px;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.page-about__mission-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 30px rgba(0,0,0,0.4);
}
.page-about__mission-card--primary {
  background: var(--about-card-bg);
  color: var(--about-card-text);
  border-left: 6px solid var(--about-accent);
}
.page-about__mission-card--accent {
  background: rgba(211,47,47,0.12);
  border: 1px solid rgba(211,47,47,0.25);
  backdrop-filter: blur(4px);
}
.page-about__mission-card--outline {
  background: rgba(245,240,225,0.04);
  border: 1px solid rgba(192,192,192,0.15);
}
.page-about__mission-text {
  margin: 0;
  font-size: 1rem;
  line-height: 1.7;
}
.page-about__mission-card--primary .page-about__mission-text {
  font-weight: 500;
}

/* ── 核心功能 ── */
.page-about__features-layout {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}
.page-about__features-image {
  width: 100%;
  border-radius: 12px;
  overflow: hidden;
  border: 1px solid rgba(192,192,192,0.15);
  box-shadow: 0 4px 20px rgba(0,0,0,0.3);
}
.page-about__features-image img {
  width: 100%;
  height: auto;
  display: block;
  object-fit: cover;
}
.page-about__features-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0;
  counter-reset: feat;
}
.page-about__feature-item {
  display: flex;
  gap: 1rem;
  padding: 1.2rem 1rem;
  border-bottom: 1px solid rgba(192,192,192,0.08);
  transition: background 0.3s, transform 0.3s;
  cursor: default;
  border-radius: 8px;
}
.page-about__feature-item:hover {
  background: rgba(245,240,225,0.05);
  transform: translateX(6px);
}
.page-about__feature-item:last-child {
  border-bottom: none;
}
.page-about__feature-number {
  font-family: Futura, Impact, sans-serif;
  font-size: 1.8rem;
  font-weight: 800;
  font-style: italic;
  color: var(--about-accent);
  line-height: 1;
  flex-shrink: 0;
  width: 2.4rem;
  text-align: right;
}
.page-about__feature-content {
  flex: 1;
}
.page-about__feature-title {
  font-family: Futura, Impact, sans-serif;
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--about-cream);
  margin: 0 0 0.3rem;
  line-height: 1.2;
}
.page-about__feature-desc {
  margin: 0;
  font-size: 0.9rem;
  color: var(--about-text);
  line-height: 1.5;
}
.page-about__feature-desc a {
  color: var(--about-accent-blue);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 0.2s;
}
.page-about__feature-desc a:hover {
  border-bottom-color: var(--about-accent-blue);
}

/* ── 筛选按钮 ── */
.page-about__filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-top: 1.8rem;
  padding-top: 1.2rem;
  border-top: 1px solid rgba(192,192,192,0.12);
}
.page-about .btn--filter {
  background: transparent;
  border: 1px solid var(--about-silver);
  color: var(--about-silver);
  font-size: 0.8rem;
  padding: 0.4rem 1rem;
  border-radius: 30px;
  cursor: pointer;
  transition: all 0.25s;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.page-about .btn--filter:hover {
  border-color: var(--about-accent);
  color: var(--about-accent-light);
  background: rgba(211,47,47,0.08);
}
.page-about .btn--filter[aria-pressed="true"] {
  background: var(--about-accent);
  border-color: var(--about-accent);
  color: #fff;
  box-shadow: 0 0 16px rgba(211,47,47,0.3);
}

/* ── 会员特权 ── */
.page-about__membership-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.2rem;
  margin-bottom: 2rem;
}
.page-about__membership-card {
  position: relative;
  border-radius: 14px;
  overflow: hidden;
  padding: 1.8rem 1.6rem;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  border: 1px solid rgba(192,192,192,0.1);
}
.page-about__membership-card:hover {
  transform: scale(1.02);
  box-shadow: 0 12px 40px rgba(0,0,0,0.5);
}
.page-about__membership-card-bg {
  position: absolute;
  inset: 0;
  opacity: 0.15;
  pointer-events: none;
}
.page-about__membership-card--highlight {
  background: linear-gradient(145deg, #2A0A0A, #1A1A1A);
  border-left: 5px solid var(--about-accent);
}
.page-about__membership-card--highlight .page-about__membership-card-bg {
  background: radial-gradient(circle at 20% 30%, var(--about-accent), transparent 70%);
}
.page-about__membership-card--sync {
  background: linear-gradient(145deg, #0A1A2A, #1A1A1A);
  border-left: 5px solid var(--about-accent-blue);
}
.page-about__membership-card--sync .page-about__membership-card-bg {
  background: radial-gradient(circle at 80% 20%, var(--about-accent-blue), transparent 70%);
}
.page-about__membership-card--access {
  background: linear-gradient(145deg, #1A1A1A, #2A1A0A);
  border-left: 5px solid var(--about-silver);
}
.page-about__membership-card--access .page-about__membership-card-bg {
  background: radial-gradient(circle at 50% 80%, var(--about-silver), transparent 70%);
}
.page-about__membership-content {
  position: relative;
  z-index: 1;
}
.page-about__membership-icon {
  font-size: 2rem;
  line-height: 1;
  margin-bottom: 0.5rem;
  color: var(--about-accent-light);
}
.page-about__membership-card--sync .page-about__membership-icon {
  color: var(--about-accent-blue);
}
.page-about__membership-card--access .page-about__membership-icon {
  color: var(--about-silver);
}
.page-about__membership-title {
  font-family: Futura, Impact, sans-serif;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--about-cream);
  margin: 0 0 0.4rem;
  line-height: 1.2;
}
.page-about__membership-desc {
  margin: 0;
  font-size: 0.9rem;
  color: var(--about-text);
  line-height: 1.6;
  max-width: 520px;
}
.page-about__membership-visual {
  width: 100%;
  max-width: 600px;
  margin: 1rem auto 0;
  border-radius: 12px;
  overflow: hidden;
  border: 1px solid rgba(192,192,192,0.1);
  box-shadow: 0 4px 20px rgba(0,0,0,0.3);
}
.page-about__membership-visual img {
  width: 100%;
  height: auto;
  display: block;
  object-fit: cover;
}

/* ── 可信赖的基础 ── */
.page-about__trust-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}
.page-about__trust-card {
  display: flex;
  align-items: center;
  gap: 1.2rem;
  background: rgba(245,240,225,0.04);
  border: 1px solid rgba(192,192,192,0.1);
  border-radius: 10px;
  padding: 1.2rem 1.4rem;
  transition: background 0.3s, transform 0.3s;
}
.page-about__trust-card:hover {
  background: rgba(245,240,225,0.08);
  transform: translateX(4px);
}
.page-about__trust-icon {
  font-size: 1.8rem;
  line-height: 1;
  color: var(--about-accent);
  flex-shrink: 0;
  width: 2.4rem;
  text-align: center;
}
.page-about__trust-info {
  flex: 1;
}
.page-about__trust-label {
  font-family: Futura, Impact, sans-serif;
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--about-silver);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin: 0 0 0.2rem;
}
.page-about__trust-value {
  margin: 0;
  font-size: 0.95rem;
  color: var(--about-cream);
  font-weight: 500;
}
.page-about__trust-statement {
  margin: 2rem 0 0;
  font-size: 0.9rem;
  color: var(--about-text);
  text-align: center;
  max-width: 660px;
  margin-left: auto;
  margin-right: auto;
  padding: 1.2rem 1.6rem;
  border-top: 1px solid rgba(192,192,192,0.1);
  line-height: 1.7;
  letter-spacing: 0.02em;
}

/* ── reveal 动画占位 ── */
.page-about .reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.page-about .reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ── 768px+ ── */
@media (min-width: 768px) {
  .page-about__hero {
    padding: 2rem 0 3.5rem;
  }
  .page-about__hero-layout {
    flex-direction: row;
    align-items: flex-start;
    gap: 2.5rem;
  }
  .page-about__hero-desc {
    flex: 1;
    max-width: 520px;
    margin-left: auto;
  }
  .page-about__brand-frame {
    width: 120px;
    height: 120px;
  }
  .page-about__title {
    font-size: 3rem;
  }
  .page-about .section-title {
    font-size: 2.2rem;
  }
  .page-about .section-number {
    font-size: 4rem;
  }
  .page-about__section {
    padding: 4.5rem 0;
  }
  .page-about__mission-grid {
    grid-template-columns: 1fr 1fr;
  }
  .page-about__mission-card:last-child {
    grid-column: 1 / -1;
    max-width: 70%;
    margin: 0 auto;
  }
  .page-about__features-layout {
    flex-direction: row;
    align-items: flex-start;
  }
  .page-about__features-image {
    flex: 1;
    max-width: 45%;
    position: sticky;
    top: 80px;
  }
  .page-about__features-list {
    flex: 1;
    max-width: 55%;
  }
  .page-about__membership-grid {
    grid-template-columns: 1fr 1fr;
  }
  .page-about__membership-card:last-child {
    grid-column: 1 / -1;
    max-width: 60%;
    margin: 0 auto;
  }
  .page-about__trust-layout {
    grid-template-columns: 1fr 1fr;
  }
}

/* ── 1024px+ ── */
@media (min-width: 1024px) {
  .page-about__hero {
    padding: 3rem 0 4.5rem;
  }
  .page-about__brand-frame {
    width: 140px;
    height: 140px;
  }
  .page-about__title {
    font-size: 3.6rem;
  }
  .page-about .section-title {
    font-size: 2.6rem;
  }
  .page-about .section-number {
    font-size: 5rem;
  }
  .page-about__mission-grid {
    grid-template-columns: 1fr 1fr 1fr;
  }
  .page-about__mission-card:last-child {
    grid-column: auto;
    max-width: 100%;
    margin: 0;
  }
  .page-about__features-image {
    max-width: 40%;
  }
  .page-about__features-list {
    max-width: 60%;
  }
  .page-about__membership-grid {
    grid-template-columns: 1fr 1fr 1fr;
  }
  .page-about__membership-card:last-child {
    grid-column: auto;
    max-width: 100%;
    margin: 0;
  }
  .page-about__membership-visual {
    margin-top: 2rem;
  }
  .page-about__trust-layout {
    grid-template-columns: repeat(4, 1fr);
  }
}