:root {
  --primary: #1E90FF;
  --secondary: #87CEFA;
  --accent: #FFA500;
  --accent2: #32CD32;
  --light: #F5F7FA;
  --dark: #333;
  --gray: #E1E5EE;
}

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

body {
  font-family: 'Roboto', sans-serif;
  line-height: 1.6;
  color: var(--dark);
  background: linear-gradient(135deg, #f5f7fa 0%, #e4e8f0 100%);
  padding: 0;
  margin: 0;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 20px;
}

.header {
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: white;
  padding: 60px 20px;
  text-align: center;
  border-radius: 0 0 20px 20px;
  box-shadow: 0 10px 30px rgba(30, 144, 255, 0.2);
  margin-bottom: 40px;
  position: relative;
  overflow: hidden;
}

.header::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: url('https://images.gptkong.com/demo/sample1.png') no-repeat center right;
  opacity: 0.1;
  background-size: contain;
}

.header h1 {
  font-size: 2.5rem;
  margin-bottom: 20px;
  position: relative;
  z-index: 2;
  text-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.header p {
  max-width: 800px;
  margin: 0 auto;
  font-size: 1.1rem;
  opacity: 0.9;
  position: relative;
  z-index: 2;
}

.notice {
  background-color: white;
  padding: 15px;
  border-radius: 8px;
  box-shadow: 0 4px 6px rgba(0,0,0,0.05);
  text-align: center;
  margin-bottom: 30px;
  font-size: 0.9rem;
  color: #666;
}

.content-grid {
  display: grid;
  grid-template-columns: 250px 1fr;
  gap: 30px;
}

@media (max-width: 768px) {
  .content-grid {
    grid-template-columns: 1fr;
  }
}

.sidebar {
  background: white;
  border-radius: 12px;
  padding: 20px;
  box-shadow: 0 4px 15px rgba(0,0,0,0.05);
  height: fit-content;
  position: sticky;
  top: 20px;
}

.sidebar h3 {
  color: var(--primary);
  margin-bottom: 15px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--gray);
}

.nav-links {
  list-style: none;
}

.nav-links li {
  margin-bottom: 10px;
}

.nav-links a {
  display: block;
  padding: 8px 12px;
  color: var(--dark);
  text-decoration: none;
  border-radius: 6px;
  transition: all 0.3s ease;
}

.nav-links a:hover {
  background: rgba(30, 144, 255, 0.1);
  color: var(--primary);
  transform: translateX(5px);
}

.main-content {
  background: white;
  border-radius: 12px;
  padding: 30px;
  box-shadow: 0 4px 15px rgba(0,0,0,0.05);
}

article h2 {
  color: var(--primary);
  margin: 30px 0 20px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--gray);
  font-size: 1.8rem;
}

article h3 {
  color: var(--primary);
  margin: 25px 0 15px;
  font-size: 1.4rem;
}

article p {
  margin-bottom: 20px;
  font-size: 1.05rem;
  line-height: 1.7;
}

article img {
  max-width: 100%;
  height: auto;
  border-radius: 8px;
  box-shadow: 0 5px 15px rgba(0,0,0,0.1);
  margin: 20px 0;
  transition: transform 0.3s ease;
}

article img:hover {
  transform: scale(1.02);
}

.image-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 20px;
  margin: 30px 0;
}

.image-grid img {
  width: 100%;
  height: 200px;
  object-fit: cover;
  border-radius: 8px;
  box-shadow: 0 5px 15px rgba(0,0,0,0.1);
  transition: all 0.3s ease;
}

.image-grid img:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 25px rgba(0,0,0,0.15);
}

pre {
  background: #282c34;
  color: #abb2bf;
  padding: 20px;
  border-radius: 8px;
  overflow-x: auto;
  margin: 20px 0;
  font-size: 0.9rem;
  line-height: 1.5;
  box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

code {
  font-family: 'Courier New', monospace;
}

.highlight-box {
  background: linear-gradient(135deg, rgba(30, 144, 255, 0.05), rgba(135, 206, 250, 0.05));
  border-left: 4px solid var(--primary);
  padding: 20px;
  border-radius: 0 8px 8px 0;
  margin: 25px 0;
}

.footer {
  text-align: center;
  padding: 30px;
  margin-top: 50px;
  color: #666;
  font-size: 0.9rem;
}

.tech-card {
  background: white;
  border-radius: 12px;
  padding: 25px;
  margin: 30px 0;
  box-shadow: 0 5px 20px rgba(0,0,0,0.08);
  border-top: 5px solid var(--primary);
  transition: transform 0.3s ease;
}

.tech-card:hover {
  transform: translateY(-5px);
}

.tech-card h3 {
  color: var(--primary);
  margin-bottom: 15px;
}

.tech-card p {
  margin-bottom: 15px;
}

.button {
  display: inline-block;
  background: var(--accent);
  color: white;
  padding: 12px 25px;
  border-radius: 6px;
  text-decoration: none;
  font-weight: 500;
  transition: all 0.3s ease;
  border: none;
  cursor: pointer;
  box-shadow: 0 4px 6px rgba(255, 165, 0, 0.2);
}

.button:hover {
  background: #FF8C00;
  transform: translateY(-2px);
  box-shadow: 0 6px 12px rgba(255, 165, 0, 0.3);
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 20px 0;
}

.tag {
  background: rgba(30, 144, 255, 0.1);
  color: var(--primary);
  padding: 5px 12px;
  border-radius: 20px;
  font-size: 0.8rem;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

.fade-in {
  animation: fadeIn 0.6s ease forwards;
}

.delay-1 { animation-delay: 0.2s; }
.delay-2 { animation-delay: 0.4s; }
.delay-3 { animation-delay: 0.6s; }

@media (max-width: 768px) {
  .header h1 {
    font-size: 2rem;
  }
  
  article h2 {
    font-size: 1.5rem;
  }
  
  article h3 {
    font-size: 1.2rem;
  }
}