.page-about {
  --about-gold: #D4AF37;
  --about-red: #C41E3A;
  --about-dark: #1A1A1A;
  --about-mid-dark: #2C2C2C;
  --about-mid-gray: #5A5A5A;
  --about-light-gray: #E5E5E5;
  --about-white: #FFFFFF;
  --about-bg-light: #F8F8F8;
  --about-font-heading: 'Noto Serif SC', 'Source Han Serif SC', 'SimSun', serif;
  --about-font-mono: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;
  --about-transition: 0.2s ease;
  --about-max-width: 1200px;
  --about-grid-gap: 24px;
  --about-card-radius: 0;
  --about-line-thin: 1px solid rgba(212, 175, 55, 0.25);
  display: block;
  width: 100%;
  background: var(--about-white);
  color: var(--about-dark);
  font-family: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
}

/* ===== 面包屑 ===== */
.about-breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--about-font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.04em;
  color: var(--about-mid-gray);
  margin-bottom: 20px;
  flex-wrap: wrap;
}
.about-breadcrumb-link {
  color: var(--about-mid-gray);
  text-decoration: none;
  transition: color var(--about-transition);
}
.about-breadcrumb-link:hover,
.about-breadcrumb-link:focus-visible {
  color: var(--about-gold);
  outline: none;
}
.about-breadcrumb-sep {
  color: var(--about-gold);
  font-weight: 300;
}
.about-breadcrumb-current {
  color: var(--about-dark);
  font-weight: 500;
}

/* ===== Hero ===== */
.about-hero {
  position: relative;
  overflow: hidden;
  background: var(--about-dark);
  min-height: 320px;
  display: flex;
  align-items: flex-end;
  padding: 0 20px 48px;
}
.about-hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}
.about-hero-bg-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 30%;
  display: block;
  opacity: 0.5;
  mix-blend-mode: luminosity;
}
.about-hero-content {
  position: relative;
  z-index: 1;
  max-width: var(--about-max-width);
  width: 100%;
  margin: 0 auto;
}
.about-hero-title {
  font-family: var(--about-font-heading);
  font-size: 2.4rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--about-white);
  margin: 0 0 12px;
  line-height: 1.2;
}
.about-hero-desc {
  font-size: 1rem;
  line-height: 1.6;
  color: rgba(255, 255, 255, 0.8);
  max-width: 600px;
  margin: 0;
}

/* ===== 通用标题 ===== */
.about-section-title {
  font-family: var(--about-font-heading);
  font-size: 1.8rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: var(--about-dark);
  margin: 0 0 20px;
  position: relative;
  padding-left: 20px;
  border-left: 4px solid var(--about-red);
}
.about-section-title::after {
  content: '';
  display: block;
  width: 48px;
  height: 2px;
  background: var(--about-gold);
  margin-top: 8px;
}

/* ===== 品牌使命 ===== */
.about-mission {
  max-width: var(--about-max-width);
  margin: 0 auto;
  padding: 60px 20px 40px;
}
.about-mission-inner {
  display: flex;
  flex-wrap: wrap;
  gap: 40px;
  align-items: flex-start;
}
.about-mission-text {
  flex: 1 1 480px;
  max-width: 680px;
}
.about-mission-desc {
  font-size: 1rem;
  line-height: 1.8;
  color: var(--about-mid-dark);
  margin: 0 0 24px;
}
.about-mission-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.about-mission-item {
  position: relative;
  padding-left: 24px;
  font-size: 0.95rem;
  line-height: 1.6;
  color: var(--about-mid-gray);
}
.about-mission-item::before {
  content: '';
  position: absolute;
  left: 0;
  top: 8px;
  width: 10px;
  height: 10px;
  background: var(--about-gold);
  border-radius: 0;
  transform: rotate(45deg);
}
.about-mission-figure {
  flex: 0 0 auto;
  margin: 0;
  width: 100%;
  max-width: 600px;
}
.about-mission-img {
  width: 100%;
  height: auto;
  max-width: 600px;
  display: block;
  border: var(--about-line-thin);
  object-fit: cover;
}

/* ===== 改版历程 ===== */
.about-timeline {
  max-width: var(--about-max-width);
  margin: 0 auto;
  padding: 40px 20px 60px;
}
.about-timeline-intro {
  font-size: 1rem;
  line-height: 1.7;
  color: var(--about-mid-gray);
  max-width: 700px;
  margin: 0 0 40px;
}
.about-timeline-track {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 0;
  padding-left: 32px;
}
.about-timeline-track::before {
  content: '';
  position: absolute;
  left: 12px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--about-gold);
  opacity: 0.4;
}
.about-timeline-node {
  position: relative;
  padding: 20px 0 20px 32px;
  border-left: none;
  transition: background var(--about-transition);
}
.about-timeline-node:first-child {
  padding-top: 0;
}
.about-timeline-node:last-child {
  padding-bottom: 0;
}
.about-timeline-marker {
  position: absolute;
  left: -26px;
  top: 28px;
  width: 16px;
  height: 16px;
  background: var(--about-red);
  border: 3px solid var(--about-white);
  border-radius: 50%;
  box-shadow: 0 0 0 2px var(--about-gold);
  z-index: 1;
  transition: transform var(--about-transition), box-shadow var(--about-transition);
  cursor: default;
}
.about-timeline-node[data-timeline-node]:hover .about-timeline-marker,
.about-timeline-node[data-timeline-node]:focus-within .about-timeline-marker {
  transform: scale(1.25);
  box-shadow: 0 0 0 4px var(--about-gold);
}
.about-timeline-card {
  background: var(--about-bg-light);
  border: var(--about-line-thin);
  padding: 20px 24px;
  transition: border-color var(--about-transition), box-shadow var(--about-transition);
}
.about-timeline-node[data-timeline-node]:hover .about-timeline-card,
.about-timeline-node[data-timeline-node]:focus-within .about-timeline-card {
  border-color: var(--about-gold);
  box-shadow: 0 2px 12px rgba(212, 175, 55, 0.08);
}
.about-timeline-card-title {
  font-family: var(--about-font-heading);
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  color: var(--about-dark);
  margin: 0 0 8px;
}
.about-timeline-card-text {
  font-size: 0.9rem;
  line-height: 1.6;
  color: var(--about-mid-gray);
  margin: 0;
}
.about-timeline-figure {
  margin: 40px 0 0;
  width: 100%;
  max-width: 700px;
}
.about-timeline-img {
  width: 100%;
  height: auto;
  display: block;
  border: var(--about-line-thin);
  object-fit: cover;
}

/* ===== 核心技术 ===== */
.about-tech {
  max-width: var(--about-max-width);
  margin: 0 auto;
  padding: 40px 20px 60px;
  border-top: 1px solid var(--about-light-gray);
}
.about-tech-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--about-grid-gap);
  margin-top: 8px;
}
.about-tech-card {
  background: var(--about-bg-light);
  border: var(--about-line-thin);
  padding: 28px 24px;
  position: relative;
  transition: border-color var(--about-transition), background var(--about-transition);
  cursor: default;
}
.about-tech-card[data-tech-card]:hover,
.about-tech-card[data-tech-card]:focus-within {
  border-color: var(--about-gold);
  background: var(--about-white);
}
.about-tech-card-num {
  font-family: var(--about-font-mono);
  font-size: 2rem;
  font-weight: 300;
  color: var(--about-gold);
  line-height: 1;
  margin-bottom: 12px;
  opacity: 0.6;
}
.about-tech-card-title {
  font-family: var(--about-font-heading);
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  color: var(--about-dark);
  margin: 0 0 8px;
}
.about-tech-card-text {
  font-size: 0.9rem;
  line-height: 1.6;
  color: var(--about-mid-gray);
  margin: 0;
}

/* ===== 联系我们 ===== */
.about-contact {
  max-width: var(--about-max-width);
  margin: 0 auto;
  padding: 40px 20px 60px;
  border-top: 1px solid var(--about-light-gray);
}
.about-contact-desc {
  font-size: 0.95rem;
  line-height: 1.7;
  color: var(--about-mid-gray);
  max-width: 600px;
  margin: 0 0 32px;
}
.about-contact-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  margin-bottom: 24px;
}
.about-contact-item {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px 16px;
  padding: 16px 20px;
  background: var(--about-bg-light);
  border-left: 3px solid var(--about-gold);
}
.about-contact-label {
  font-family: var(--about-font-mono);
  font-size: 0.8rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--about-mid-gray);
  min-width: 48px;
}
.about-contact-value {
  font-size: 0.95rem;
  color: var(--about-dark);
  text-decoration: none;
  transition: color var(--about-transition);
}
.about-contact-value[href]:hover,
.about-contact-value[href]:focus-visible {
  color: var(--about-red);
  outline: none;
}
.about-contact-note {
  font-size: 0.85rem;
  color: var(--about-mid-gray);
  margin: 0 0 24px;
  padding: 12px 16px;
  background: rgba(212, 175, 55, 0.06);
  border: 1px solid rgba(212, 175, 55, 0.2);
}
.about-contact-links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 24px;
}
.about-contact-link {
  font-family: var(--about-font-mono);
  font-size: 0.85rem;
  letter-spacing: 0.04em;
  color: var(--about-mid-dark);
  text-decoration: none;
  padding: 4px 0;
  border-bottom: 1px solid transparent;
  transition: border-color var(--about-transition), color var(--about-transition);
}
.about-contact-link:hover,
.about-contact-link:focus-visible {
  border-bottom-color: var(--about-red);
  color: var(--about-red);
  outline: none;
}

/* ===== 响应式 - 平板 768px ===== */
@media (min-width: 768px) {
  .about-hero {
    padding: 0 40px 64px;
    min-height: 380px;
  }
  .about-hero-title {
    font-size: 3rem;
  }
  .about-hero-desc {
    font-size: 1.1rem;
  }
  .about-section-title {
    font-size: 2rem;
    padding-left: 24px;
  }
  .about-mission,
  .about-timeline,
  .about-tech,
  .about-contact {
    padding-left: 40px;
    padding-right: 40px;
  }
  .about-mission-inner {
    flex-wrap: nowrap;
  }
  .about-timeline-track {
    padding-left: 48px;
  }
  .about-timeline-track::before {
    left: 20px;
  }
  .about-timeline-marker {
    left: -38px;
    top: 28px;
    width: 20px;
    height: 20px;
  }
  .about-timeline-node {
    padding: 24px 0 24px 40px;
  }
  .about-tech-grid {
    grid-template-columns: repeat(3, 1fr);
  }
  .about-contact-grid {
    grid-template-columns: repeat(3, 1fr);
  }
  .about-contact-links {
    gap: 16px 32px;
  }
  .about-contact-link {
    font-size: 0.9rem;
  }
}

/* ===== 响应式 - 桌面 1024px ===== */
@media (min-width: 1024px) {
  .about-hero {
    padding: 0 60px 80px;
    min-height: 420px;
  }
  .about-hero-title {
    font-size: 3.6rem;
  }
  .about-mission,
  .about-timeline,
  .about-tech,
  .about-contact {
    padding-left: 60px;
    padding-right: 60px;
  }
  .about-mission-inner {
    gap: 60px;
  }
  .about-section-title {
    font-size: 2.2rem;
  }
  .about-timeline-intro {
    font-size: 1.05rem;
  }
  .about-tech-card {
    padding: 32px 28px;
  }
  .about-contact-item {
    padding: 20px 24px;
  }
}

/* ===== 响应式 - 大屏 1440px ===== */
@media (min-width: 1440px) {
  .about-hero {
    padding: 0 80px 96px;
  }
  .about-mission,
  .about-timeline,
  .about-tech,
  .about-contact {
    padding-left: 80px;
    padding-right: 80px;
  }
}