/* Reset cơ bản */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: Arial, sans-serif;
}

body {
  line-height: 1.6;
  color: #333;
  background-color: #f9f9f9;
}

.container {
  max-width: 900px;
  margin: 0 auto;
  padding: 20px;
  background: #fff;
}

/* Menu điều hướng */
nav {
  display: flex;
  gap: 20px;
  padding: 15px 0;
  border-bottom: 1px solid #eee;
  margin-bottom: 20px;
}

nav a {
  text-decoration: none;
  color: #0066cc;
  font-weight: bold;
  font-size: 1.1rem;
}

nav a:hover {
  text-decoration: underline;
}

/* Banner & Avatar */
.header-banner {
  width: 100%;
  border-radius: 8px;
  margin-bottom: 20px;
}

.profile-header {
  text-align: center;
  margin-bottom: 30px;
}

.avatar {
  width: 130px;
  height: 130px;
  border-radius: 50%;
  object-fit: cover;
  margin-bottom: 10px;
}

/* Nội dung giới thiệu */
.about-section {
  margin: 30px 0;
  padding: 20px 0;
  border-top: 1px solid #eee;
}

.about-section h3 {
  margin-bottom: 15px;
  color: #222;
}

.about-section ol {
  margin-left: 20px;
  margin-bottom: 15px;
}

blockquote {
  background: #eef6ff;
  border-left: 4px solid #0066cc;
  padding: 10px 15px;
  margin: 15px 0;
  font-style: italic;
}

/* Khung bài viết (Grid/Card) */
.post-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
  margin-top: 20px;
}

.post-card {
  border: 1px solid #e0e0e0;
  border-radius: 8px;
  overflow: hidden;
  background: #fff;
  transition: transform 0.2s;
}

.post-card:hover {
  transform: translateY(-4px);
}

/* Ảnh thumbnail tỉ lệ 16:9 */
.thumb-16-9 {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  display: block;
}

.post-content {
  padding: 15px;
}

.post-title {
  font-size: 1.2rem;
  margin-bottom: 8px;
}

.post-title a {
  color: #111;
  text-decoration: none;
}

.post-title a:hover {
  color: #0066cc;
}

.meta-description {
  font-size: 0.9rem;
  color: #666;
}