a,
body {
  color: #333;
}
body,
header {
  background-color: #fff;
}
.sidebar-section h3,
header {
  border-bottom: 1px solid #e0e0e0;
}
.article-meta,
.main-content,
.meta-item,
.tag-list,
nav ul {
  display: flex;
}
.ad-space,
footer {
  background-color: #f9f9f9;
}
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
body {
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  line-height: 1.6;
}
a {
  text-decoration: none;
}
ul {
  list-style: none;
}
img {
  max-width: 100%;
}
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}
header {
  padding: 20px 0;
}
.header-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.logo {
  font-size: 24px;
  font-weight: 700;
  color: #000;
}
nav ul li {
  margin-left: 25px;
}
nav ul li a {
  font-weight: 500;
  transition: color 0.3s;
}
.related-post a:hover,
.tool-item a:hover,
nav ul li a:hover {
  color: #666;
}
.main-content {
  margin: 40px 0;
}
.sidebar-left {
  width: 20%;
  padding-right: 30px;
  order: 1;
}
.popular-tools,
.related-posts,
.sidebar-section {
  margin-bottom: 40px;
}
.sidebar-section h3 {
  font-size: 18px;
  margin-bottom: 15px;
  padding-bottom: 10px;
}
.footer-section ul li,
.recent-posts li,
.seo-tags li {
  margin-bottom: 10px;
}
.recent-posts a,
.seo-tags a {
  display: block;
  padding: 8px 0;
  border-bottom: 1px solid #f0f0f0;
  transition: 0.3s;
}
.recent-posts a:hover,
.seo-tags a:hover {
  background-color: #f9f9f9;
  padding-left: 10px;
}
.content {
  width: 60%;
  padding: 0 30px;
  order: 2;
}
.article-tags,
.copyright {
  margin-top: 40px;
  padding-top: 20px;
  border-top: 1px solid #e0e0e0;
}
.article-header {
  margin-bottom: 30px;
}
.article-title {
  font-size: 32px;
  margin-bottom: 15px;
  line-height: 1.3;
}
.article-content p,
.article-meta {
  margin-bottom: 20px;
}
.article-meta {
  flex-wrap: wrap;
  font-size: 14px;
  color: #666;
}
.meta-item {
  margin-right: 20px;
  align-items: center;
}
.meta-item i {
  margin-right: 5px;
}
.article-image {
  margin-bottom: 25px;
}
.article-image img {
  width: 100%;
  height: auto;
}
.article-content {
  font-size: 16px;
  line-height: 1.7;
}
.article-content h2 {
  font-size: 24px;
  margin: 30px 0 15px;
}
.article-content h3 {
  font-size: 20px;
  margin: 25px 0 15px;
}
.article-content h4 {
  font-size: 18px;
  margin: 20px 0 10px;
}
.article-content blockquote {
  border-left: 4px solid #e0e0e0;
  padding-left: 20px;
  margin: 25px 0;
  font-style: italic;
  color: #666;
}
.article-content ul {
  list-style-type: disc;
  margin-left: 20px;
  margin-bottom: 20px;
}
.article-content li {
  margin-bottom: 8px;
}
.article-tags h3 {
  font-size: 16px;
  margin-bottom: 10px;
}
.tag-list {
  flex-wrap: wrap;
}
.tag-list a {
  display: inline-block;
  background-color: #f5f5f5;
  padding: 5px 12px;
  margin-right: 10px;
  margin-bottom: 10px;
  border-radius: 3px;
  font-size: 14px;
  transition: background-color 0.3s;
}
.tag-list a:hover {
  background-color: #e0e0e0;
}
.ad-space {
  border: 1px solid #e0e0e0;
  padding: 20px;
  text-align: center;
  margin-bottom: 30px;
}
.ad-space h3 {
  font-size: 16px;
  margin-bottom: 10px;
  color: #666;
}
.mobile-ad {
  display: none;
}
.sidebar-right {
  width: 20%;
  padding-left: 30px;
  order: 3;
}
.related-post,
.tool-item {
  margin-bottom: 15px;
  padding-bottom: 15px;
  border-bottom: 1px solid #f0f0f0;
}
.related-post:last-child,
.tool-item:last-child {
  border-bottom: none;
}
.related-post a,
.tool-item a {
  display: block;
  transition: color 0.3s;
}
footer {
  padding: 40px 0;
  border-top: 1px solid #e0e0e0;
}
.footer-content {
  display: flex;
  justify-content: space-between;
}
.footer-section {
  width: 30%;
}
.footer-section h3 {
  font-size: 18px;
  margin-bottom: 20px;
}
.copyright {
  text-align: center;
  color: #666;
  font-size: 14px;
}
@media (max-width: 992px) {
  .footer-content,
  .main-content {
    flex-direction: column;
  }
  .content,
  .sidebar-left,
  .sidebar-right {
    width: 100%;
    padding: 0;
  }
  .sidebar-left {
    order: 3;
    margin-top: 40px;
  }
  .content {
    order: 1;
  }
  .sidebar-right {
    order: 2;
    margin-bottom: 40px;
  }
  .mobile-ad {
    display: block;
    margin: 25px 0;
  }
  .footer-section {
    width: 100%;
    margin-bottom: 30px;
  }
}
@media (max-width: 768px) {
  .header-container {
    flex-direction: column;
    text-align: center;
  }
  nav ul {
    margin-top: 15px;
    justify-content: center;
  }
  nav ul li {
    margin: 0 10px;
  }
  .article-title {
    font-size: 26px;
  }
}