/* =========================================
   光学知识文章独立页面样式
   ========================================= */

/* 面包屑 */
.breadcrumb {
  padding: 16px 0;
  font-size: 0.85rem;
  color: var(--text-muted);
}
.breadcrumb a {
  color: var(--text-secondary);
  transition: color var(--transition);
}
.breadcrumb a:hover { color: var(--primary); }
.breadcrumb .sep {
  margin: 0 8px;
  color: var(--border-dark);
}

/* 文章主体 */
.article-wrap {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 0 80px;
}

.article-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 40px 48px;
  margin-bottom: 32px;
  box-shadow: var(--shadow-sm);
}

.article-card h2 {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--text);
  margin-bottom: 20px;
  line-height: 1.4;
}

.article-card h3 {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--primary);
  margin: 28px 0 12px;
  padding-left: 14px;
  border-left: 4px solid var(--primary);
}

.article-card h3:first-of-type { margin-top: 8px; }

.article-card h4 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text);
  margin: 22px 0 10px;
}

.article-card p {
  font-size: 0.94rem;
  line-height: 1.9;
  color: var(--text-secondary);
  margin-bottom: 14px;
  text-align: justify;
}
.article-card p:last-child { margin-bottom: 0; }

.article-card ul, .article-card ol {
  margin: 10px 0 16px 22px;
}
.article-card li {
  font-size: 0.94rem;
  line-height: 1.85;
  color: var(--text-secondary);
  margin-bottom: 6px;
}
.article-card strong { color: var(--text); }

/* 文章插图 */
.article-figure {
  margin: 24px 0;
  text-align: center;
}
.article-figure img {
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
}
.article-figure figcaption {
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-top: 10px;
  font-style: italic;
}

/* 公式居中 */
.formula {
  text-align: center;
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text);
  margin: 18px 0;
  padding: 14px;
  background: var(--bg);
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
}

/* 对比表格 */
.article-card table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
  margin: 16px 0;
}
.article-card thead tr {
  background: var(--primary);
  color: #fff;
}
.article-card th {
  padding: 11px 16px;
  text-align: left;
  font-weight: 700;
  font-size: 0.85rem;
}
.article-card td {
  padding: 10px 16px;
  border-bottom: 1px solid var(--border);
  color: var(--text-secondary);
  line-height: 1.6;
}
.article-card tbody tr:hover {
  background: var(--bg);
}

/* CTA 服务卡片 */
.service-cta {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  border-radius: var(--radius);
  padding: 36px 44px;
  color: #fff;
  margin: 36px 0;
}
.service-cta h3 {
  font-size: 1.2rem;
  font-weight: 800;
  color: #fff;
  border-left: 4px solid rgba(255,255,255,0.6);
  padding-left: 14px;
  margin: 0 0 14px;
}
.service-cta p {
  font-size: 0.93rem;
  line-height: 1.8;
  color: rgba(255,255,255,0.92);
  margin-bottom: 10px;
}
.service-cta p:last-child { margin-bottom: 0; }
.service-cta ul {
  margin: 10px 0 14px 20px;
}
.service-cta li {
  color: rgba(255,255,255,0.9);
  font-size: 0.92rem;
  line-height: 1.7;
  margin-bottom: 4px;
}
.service-cta .cta-btns {
  display: flex;
  gap: 12px;
  margin-top: 20px;
  flex-wrap: wrap;
}
.service-cta .cta-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 11px 26px;
  background: #fff;
  color: var(--primary);
  border-radius: var(--radius-sm);
  font-weight: 700;
  font-size: 0.92rem;
  text-decoration: none;
  transition: all var(--transition);
}
.service-cta .cta-btn:hover {
  background: rgba(255,255,255,0.9);
  transform: translateY(-1px);
}
.service-cta .cta-btn-outline {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 11px 26px;
  background: transparent;
  color: #fff;
  border: 2px solid rgba(255,255,255,0.6);
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 0.92rem;
  text-decoration: none;
  transition: all var(--transition);
}
.service-cta .cta-btn-outline:hover {
  border-color: #fff;
  background: rgba(255,255,255,0.1);
}

/* 返回链接 */
.back-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.92rem;
  color: var(--primary);
  text-decoration: none;
  font-weight: 600;
  padding: 12px 0 40px;
  transition: color var(--transition);
}
.back-link:hover {
  color: var(--primary-dark);
}

/* 响应式 */
@media (max-width: 768px) {
  .article-card {
    padding: 28px 22px;
  }
  .service-cta {
    padding: 28px 24px;
  }
}