* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: "Inter", sans-serif;
  line-height: 1.6;
  color: #222;
  background-color: #fff;
}

/* Banner */
.banner img {
  width: 100%;
  height: 250px;
  object-fit: cover;
  filter: brightness(80%);
  transition: filter 0.3s ease;
}

.banner img:hover {
  filter: brightness(90%);
}

/* Layout */
.layout {
  display: flex;
  justify-content: center;
  align-items: flex-start;
  max-width: 1200px;
  margin: 40px auto;
  gap: 40px;
  padding: 0 20px;
}

/* Nội dung chính */
.container {
  flex: 3;
  max-width: 750px;
  animation: fadeIn 1s ease both;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(15px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.author {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 20px;
}

.avatar img {
  width: 60px;
  height: 60px;
  border-radius: 50%;
  border: 2px solid #ddd;
}

.meta .date {
  color: #666;
  font-size: 14px;
}

.meta .author-name {
  font-size: 15px;
  color: #333;
}

.post h1 {
  font-size: 2rem;
  margin: 20px 0;
  color: #111;
  animation: fadeIn 1s ease both;
}

.post h2 {
  font-size: 1.4rem;
  margin-top: 35px;
  color: #222;
  scroll-margin-top: 80px;
  opacity: 0;
  transform: translateY(10px);
  animation: fadeIn 1s ease forwards;
}

.post p {
  margin: 10px 0 15px;
  font-size: 16px;
}

.video-link a {
  color: #0073ff;
  text-decoration: none;
}

.video-link a:hover {
  text-decoration: underline;
}

/* Mục lục bên phải */
.toc {
  flex: 1;
  position: sticky;
  top: 100px;
  align-self: flex-start;
  border-left: 2px solid #eee;
  padding-left: 20px;
  animation: fadeIn 0.8s ease both;
}

.toc h3 {
  font-size: 1.1rem;
  margin-bottom: 10px;
  color: #111;
}

.toc ul {
  list-style: none;
}

.toc li {
  margin: 8px 0;
  position: relative;
}

.toc a {
  color: #333;
  text-decoration: none;
  font-size: 15px;
  display: inline-block;
  padding: 4px 0;
  transition: color 0.25s ease, transform 0.2s ease;
}

.toc a:hover {
  color: #0073ff;
  transform: translateX(3px);
}

/* Highlight mục đang xem */
.toc a.active {
  color: #0073ff;
  font-weight: 600;
}

.toc a.active::before {
  content: "";
  position: absolute;
  left: -10px;
  top: 8px;
  width: 3px;
  height: 14px;
  background: #0073ff;
  border-radius: 2px;
}

/* Footer */
footer {
  text-align: center;
  padding: 20px;
  color: #777;
  font-size: 14px;
  border-top: 1px solid #eee;
  margin-top: 50px;
}
.related-posts {
  margin: 60px 0;
  padding: 20px;
  border-top: 1px solid #eee;
}

.related-posts h2 {
  font-size: 1.8em;
  font-weight: 700;
  margin-bottom: 20px;
  color: #222;
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
}

.related-card {
  display: flex;
  flex-direction: column;
  background: #fff;
  border-radius: 12px;
  text-decoration: none;
  color: inherit;
  overflow: hidden;
  box-shadow: 0 2px 8px rgba(0,0,0,0.08);
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.related-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 6px 16px rgba(0,0,0,0.15);
}

.related-card img {
  width: 100%;
  height: 160px;
  object-fit: cover;
}

.related-content {
  padding: 14px 16px;
}

.related-content h3 {
  font-size: 1.05em;
  margin: 0 0 6px;
  line-height: 1.4;
  color: #0a4b8c;
  transition: color 0.25s ease;
}

.related-card:hover h3 {
  color: #007bff;
}

.related-content p {
  font-size: 0.9em;
  color: #555;
}

.linux-commands-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 20px;
  margin-top: 20px;
}

.command-card {
  background: #f9f9f9;
  border: 1px solid #e0e0e0;
  border-radius: 8px;
  padding: 12px;
  text-align: center;
  box-shadow: 0 2px 4px rgba(0,0,0,0.05);
  transition: transform 0.2s, box-shadow 0.2s;
}

.command-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 4px 8px rgba(0,0,0,0.1);
}

.command-card img {
  width: 60px;
  height: 60px;
  object-fit: cover;
  border-radius: 6px;
  margin-bottom: 10px;
}

.command-card h3 {
  margin: 8px 0 4px;
  font-size: 16px;
  color: #333;
}

.command-card p {
  font-size: 13px;
  color: #666;
  margin: 0 0 8px;
}

.command-card code {
  display: block;
  background: #eee;
  padding: 4px 6px;
  border-radius: 4px;
  font-size: 12px;
  color: #d32f2f;
}
.advanced-command-section {
  margin-top: 24px;
  line-height: 1.6;
}

.command-detail {
  margin-bottom: 40px;
  padding-bottom: 20px;
  border-bottom: 1px solid #eee;
}

.command-detail h3 {
  color: #2c3e50;
  margin-bottom: 16px;
}

.command-content {
  display: flex;
  gap: 20px;
  align-items: flex-start;
  flex-wrap: wrap;
}

.command-content img {
  width: 300px;
  height: 160px;
  object-fit: cover;
  border-radius: 8px;
  flex-shrink: 0;
}

.command-content .text {
  flex: 1;
  min-width: 300px;
}

.command-content pre {
  background: #f8f9fa;
  padding: 12px;
  border-radius: 6px;
  overflow-x: auto;
  font-size: 14px;
  border: 1px solid #eee;
}

.command-content code {
  font-family: monospace;
  color: #d32f2f;
  background: #f5f5f5;
  padding: 2px 4px;
  border-radius: 3px;
}

.command-content ul {
  padding-left: 20px;
  margin: 12px 0;
}

.command-content li {
  margin-bottom: 6px;
}
/* Đảm bảo layout mặc định cho desktop */
.layout {
  display: flex;
  gap: 2rem;
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem;
}

.container {
  flex: 3;
  min-width: 0;
}

.toc {
  flex: 1;
  background: #f9f9f9;
  padding: 1.5rem;
  border-radius: 8px;
  align-self: flex-start;
  position: sticky;
  top: 2rem;
}

/* Responsive: trên mobile, xếp chồng và thu nhỏ */
@media (max-width: 768px) {
  .layout {
    flex-direction: column;
    padding: 1rem;
    gap: 1.5rem;
  }

  .container,
  .toc {
    width: 100%;
    flex: none;
  }

  .toc {
    position: static; /* bỏ sticky trên mobile */
    padding: 1rem;
    font-size: 0.95rem;
  }

  .toc h3 {
    font-size: 1.1rem;
  }

  .toc ul {
    padding-left: 1rem;
  }

  /* Tùy chọn: thu nhỏ font hoặc khoảng cách nếu cần */
  article h1 {
    font-size: 1.6rem;
  }

  article h2 {
    font-size: 1.3rem;
  }

  .author {
    display: flex;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
  }

  .avatar img {
    width: 50px;
    height: 50px;
    border-radius: 50%;
  }

  .meta {
    font-size: 0.9rem;
  }
}