.page-about {
  --page-about-muted: rgba(245, 247, 250, 0.72);
  --page-about-card-text: rgba(17, 24, 39, 0.72);
  color: var(--light-gray);
}

/* 面包屑 */
.page-about .breadcrumb {
  padding-top: 1.5rem;
  padding-bottom: 1rem;
  font-size: 0.85rem;
  letter-spacing: 0.02em;
  color: var(--page-about-muted);
}
.page-about .breadcrumb a {
  color: var(--neon-green);
  text-decoration: none;
  transition: color var(--transition-fast);
}
.page-about .breadcrumb a:hover {
  color: var(--pure-white);
}
.page-about .breadcrumb__sep {
  margin: 0 0.5rem;
  color: rgba(245, 247, 250, 0.35);
}

/* 章节共用 */
.page-about .section__label {
  color: var(--neon-green);
  font-family: var(--font-body);
  font-size: 0.85rem;
  font-weight: 500;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

/* 首屏拼贴 */
.page-about__hero {
  position: relative;
  padding: 2rem 0 4rem;
  overflow: hidden;
}
.page-about__hero::before {
  content: '';
  position: absolute;
  top: -16%;
  right: -18%;
  width: 72%;
  height: 120%;
  background: linear-gradient(135deg, var(--mid-blue) 0%, transparent 72%);
  clip-path: polygon(15% 0, 100% 0, 100% 100%, 0% 100%);
  opacity: 0.7;
  z-index: 0;
  pointer-events: none;
}
.page-about__hero::after {
  content: '';
  position: absolute;
  bottom: -24%;
  left: -8%;
  width: 48%;
  height: 64%;
  background: radial-gradient(circle, rgba(181, 55, 242, 0.16) 0%, transparent 70%);
  z-index: 0;
  pointer-events: none;
}
.page-about__hero-grid {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 2rem;
}
.page-about__hero h1 {
  font-family: var(--font-title);
  font-size: var(--font-title-size);
  font-weight: 900;
  line-height: 1.08;
  letter-spacing: -0.015em;
  color: var(--pure-white);
  margin: 0.75rem 0 1.25rem;
  max-width: 720px;
}
.page-about__hero-lead {
  color: var(--page-about-muted);
  font-size: 1.06rem;
  line-height: 1.75;
  max-width: 640px;
  margin: 0 0 1.75rem;
}
.page-about__hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
}
.page-about__hero-stats {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.9rem;
}
.page-about__stat {
  background: var(--glass-white);
  -webkit-backdrop-filter: blur(6px);
  backdrop-filter: blur(6px);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 0.85rem;
  padding: 1.1rem;
  transition: border-color var(--transition-fast), transform var(--transition-fast);
}
.page-about__stat:hover {
  border-color: rgba(0, 255, 157, 0.35);
  transform: translateY(-2px);
}
.page-about__stat-num {
  display: block;
  font-family: var(--font-title);
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 900;
  line-height: 1.1;
  color: var(--neon-green);
}
.page-about__stat-label {
  display: block;
  margin-top: 0.35rem;
  font-size: 0.82rem;
  color: rgba(245, 247, 250, 0.68);
}

/* 起点与使命 */
.page-about__origin {
  position: relative;
  padding: 4rem 0;
  background: linear-gradient(180deg, transparent, rgba(30, 58, 110, 0.22) 100%);
}
.page-about__origin-grid {
  display: grid;
  gap: 2.5rem;
  align-items: center;
}
.page-about__origin-text h2,
.page-about__milestones h2,
.page-about__philosophy h2,
.page-about__promise h2 {
  font-family: var(--font-title);
  font-size: clamp(1.6rem, 3.2vw, 2.4rem);
  font-weight: 900;
  line-height: 1.12;
  letter-spacing: -0.01em;
  margin: 0.5rem 0 1.25rem;
}
.page-about__origin-text h2 {
  color: var(--pure-white);
}
.page-about__origin-text p {
  color: var(--page-about-muted);
  line-height: 1.8;
  margin: 0 0 1rem;
}
.page-about__origin-list {
  list-style: none;
  margin: 1.5rem 0 0;
  padding: 0;
}
.page-about__origin-list li {
  position: relative;
  padding: 0.45rem 0 0.45rem 1.4rem;
  color: rgba(245, 247, 250, 0.88);
  line-height: 1.65;
  font-size: 0.95rem;
}
.page-about__origin-list li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.9rem;
  width: 8px;
  height: 8px;
  background: var(--electric-purple);
  clip-path: polygon(50% 0, 100% 100%, 0 100%);
}
.page-about__text-link {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  margin-top: 1.5rem;
  color: var(--neon-green);
  font-weight: 600;
  text-decoration: none;
  border-bottom: 1px solid transparent;
  padding-bottom: 0.15rem;
  transition: border-color var(--transition-fast), gap var(--transition-fast);
}
.page-about__text-link:hover {
  border-bottom-color: var(--neon-green);
  gap: 0.8rem;
}
.page-about__origin-image {
  position: relative;
  border-radius: 1rem;
  overflow: hidden;
}
.page-about__origin-image img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

/* 里程碑 */
.page-about__milestones {
  position: relative;
  padding: 4rem 0;
}
.page-about__milestones::before {
  content: '';
  position: absolute;
  top: 8%;
  right: 0;
  width: 42%;
  height: 72%;
  background: linear-gradient(180deg, rgba(181, 55, 242, 0.14), transparent 80%);
  clip-path: polygon(100% 0, 100% 100%, 0 100%);
  pointer-events: none;
  z-index: 0;
}
.page-about__milestones > .container {
  position: relative;
  z-index: 1;
}
.page-about__milestones h2 {
  color: var(--pure-white);
}
.page-about__milestones-lead,
.page-about__philosophy-lead {
  color: var(--page-about-muted);
  font-size: 1rem;
  line-height: 1.75;
  max-width: 720px;
  margin: 0 0 3rem;
}

/* 竖排时间轴 */
.page-about__timeline {
  position: relative;
  padding-left: 0;
}
.page-about__timeline::before {
  content: '';
  position: absolute;
  left: 72px;
  top: 4px;
  bottom: 4px;
  width: 2px;
  background: linear-gradient(180deg, rgba(0, 255, 157, 0.55), rgba(181, 55, 242, 0.5), rgba(0, 255, 157, 0.3));
  opacity: 0.8;
}
.page-about__timeline-item {
  display: grid;
  grid-template-columns: 72px 1fr;
  gap: 1.25rem;
  position: relative;
  margin-bottom: 2.5rem;
}
.page-about__timeline-item:last-child {
  margin-bottom: 0;
}
.page-about__timeline-meta {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  text-align: right;
  padding-right: 1rem;
  padding-top: 0.25rem;
}
.page-about__timeline-dot {
  position: absolute;
  right: -7px;
  top: 6px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--neon-green);
  box-shadow: 0 0 0 4px rgba(0, 255, 157, 0.14), 0 0 20px rgba(0, 255, 157, 0.5);
  transition: transform var(--transition-fast), background var(--transition-fast), box-shadow var(--transition-fast);
  z-index: 1;
}
.page-about__timeline-item:hover .page-about__timeline-dot {
  transform: scale(1.22);
  background: var(--pure-white);
  box-shadow: 0 0 0 5px rgba(0, 255, 157, 0.2), 0 0 28px rgba(0, 255, 157, 0.85);
}
.page-about__timeline-year {
  font-family: var(--font-title);
  font-size: 0.88rem;
  font-weight: 900;
  letter-spacing: 0.03em;
  color: var(--neon-green);
  white-space: nowrap;
  margin-top: 1.6rem;
}
.page-about__timeline-card {
  background: var(--glass-white);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 1rem;
  padding: 1.5rem 1.4rem;
  transition: transform var(--transition-base), border-color var(--transition-base), background var(--transition-base);
}
.page-about__timeline-card:hover {
  transform: translateX(4px);
  border-color: rgba(0, 255, 157, 0.35);
  background: rgba(255, 255, 255, 0.12);
}
.page-about__timeline-card h3 {
  font-family: var(--font-title);
  font-size: 1.05rem;
  font-weight: 900;
  color: var(--pure-white);
  margin: 0.75rem 0 0.5rem;
}
.page-about__timeline-card p {
  color: rgba(245, 247, 250, 0.72);
  font-size: 0.93rem;
  line-height: 1.68;
  margin: 0;
}

/* 里程碑图文 */
.page-about__milestones-gallery {
  display: grid;
  gap: 1.5rem;
  margin-top: 3rem;
  align-items: center;
}
.page-about__milestones-gallery img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: 1rem;
}
.page-about__milestones-note {
  background: var(--glass-white);
  -webkit-backdrop-filter: blur(6px);
  backdrop-filter: blur(6px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 1rem;
  padding: 1.5rem;
}
.page-about__milestones-note p {
  margin: 0;
  color: rgba(245, 247, 250, 0.8);
  line-height: 1.75;
  font-size: 0.95rem;
}

/* 技术哲学 */
.page-about__philosophy {
  position: relative;
  padding: 4rem 0;
  background: linear-gradient(90deg, rgba(30, 58, 110, 0.3), transparent 80%);
}
.page-about__philosophy-grid {
  display: grid;
  gap: 2.5rem;
  align-items: center;
}
.page-about__philosophy-image {
  position: relative;
  overflow: hidden;
  border-radius: 1rem;
}
.page-about__philosophy-img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}
.page-about__philosophy-image::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(0, 255, 157, 0.22), rgba(181, 55, 242, 0.18));
  mix-blend-mode: screen;
  pointer-events: none;
  border-radius: 1rem;
}
.page-about__philosophy-text h2 {
  color: var(--pure-white);
}
.page-about__philosophy-cards {
  display: grid;
  gap: 1rem;
  margin-top: 2rem;
}
.page-about__philosophy-card {
  background: var(--pure-white);
  border-radius: 0.85rem;
  padding: 1.4rem 1.5rem;
  border-left: 4px solid var(--electric-purple);
  box-shadow: 0 4px 14px rgba(11, 27, 61, 0.12);
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}
.page-about__philosophy-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 10px 28px rgba(11, 27, 61, 0.2);
}
.page-about__philosophy-card h3 {
  font-family: var(--font-title);
  font-size: 1rem;
  font-weight: 900;
  color: var(--ink-black);
  margin: 0 0 0.5rem;
}
.page-about__philosophy-card p {
  color: var(--page-about-card-text);
  font-size: 0.9rem;
  line-height: 1.7;
  margin: 0;
}

/* 用户承诺 */
.page-about__promise {
  position: relative;
  padding: 4rem 0;
  background: var(--light-gray);
  color: var(--ink-black);
}
.page-about__promise .section__label {
  color: var(--electric-purple);
}
.page-about__promise h2 {
  color: var(--ink-black);
}
.page-about__promise-lead {
  color: rgba(17, 24, 39, 0.7);
  font-size: 1rem;
  line-height: 1.75;
  max-width: 720px;
  margin: 0 0 2.5rem;
}
.page-about__promise-grid {
  display: grid;
  gap: 1.5rem;
}
.page-about__promise-item {
  background: var(--pure-white);
  border-radius: 1rem;
  padding: 1.75rem;
  border-top: 3px solid var(--neon-green);
  box-shadow: 0 4px 16px rgba(11, 27, 61, 0.08);
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}
.page-about__promise-item:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 32px rgba(11, 27, 61, 0.15);
}
.page-about__promise-num {
  display: inline-block;
  font-family: var(--font-title);
  font-size: 0.78rem;
  font-weight: 900;
  letter-spacing: 0.12em;
  color: var(--electric-purple);
  background: rgba(181, 55, 242, 0.1);
  border-radius: 999px;
  padding: 0.25rem 0.7rem;
  margin-bottom: 1rem;
}
.page-about__promise-item h3 {
  font-family: var(--font-title);
  font-size: 1.15rem;
  font-weight: 900;
  color: var(--ink-black);
  margin: 0 0 0.5rem;
}
.page-about__promise-item p {
  color: var(--page-about-card-text);
  font-size: 0.93rem;
  line-height: 1.7;
  margin: 0;
}
.page-about__promise-cta {
  margin-top: 3rem;
  padding: 2rem;
  background: linear-gradient(135deg, var(--deep-space-blue), var(--mid-blue));
  border-radius: 1rem;
  color: var(--light-gray);
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  align-items: flex-start;
}
.page-about__promise-cta p {
  margin: 0;
  font-family: var(--font-title);
  font-size: 1.15rem;
  font-weight: 900;
  color: var(--pure-white);
}
.page-about__promise-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
}

/* 平板 */
@media (min-width: 768px) {
  .page-about__hero-stats {
    grid-template-columns: repeat(4, 1fr);
  }
  .page-about__promise-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .page-about__milestones-gallery {
    grid-template-columns: 1fr 1fr;
  }
}

/* 桌面 */
@media (min-width: 900px) {
  .page-about__hero {
    padding: 3rem 0 5rem;
  }
  .page-about__hero-grid {
    grid-template-columns: 1.35fr 1fr;
    gap: 3.5rem;
    align-items: end;
  }
  .page-about__hero-stats {
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
  }
  .page-about__origin-grid {
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
  }
  .page-about__origin-image::before {
    content: '';
    position: absolute;
    inset: -1.25rem auto -1.75rem -1.25rem;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, rgba(0, 255, 157, 0.1), rgba(181, 55, 242, 0.12));
    clip-path: polygon(0 0, 100% 12%, 100% 100%, 0 100%);
    z-index: -1;
    border-radius: 1rem;
    pointer-events: none;
  }
  .page-about__timeline::before {
    left: 133px;
  }
  .page-about__timeline-item {
    grid-template-columns: 132px 1fr;
    gap: 2rem;
    margin-bottom: 3rem;
  }
  .page-about__timeline-year {
    font-size: 1rem;
  }
  .page-about__philosophy-grid {
    grid-template-columns: 0.9fr 1.1fr;
    gap: 4rem;
  }
}