:root {
  --primary: linear-gradient(135deg, #FF7F50 0%, #8A2BE2 100%);
  --secondary: rgba(255, 255, 255, 0.9);
  --accent: #FFD700;
  --text: #2C3E50;
  --light: #F8F9FA;
  --shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
  --radius: 16px;
  --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

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

body {
  font-family: 'Roboto', 'Montserrat', sans-serif;
  color: var(--text);
  background: var(--light);
  line-height: 1.7;
  overflow-x: hidden;
}

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

.header {
  background: var(--primary);
  color: white;
  padding: 80px 0;
  text-align: center;
  position: relative;
  overflow: hidden;
  margin-bottom: 60px;
}

.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/contain;
  opacity: 0.15;
}

.header h1 {
  font-size: 3rem;
  margin-bottom: 20px;
  position: relative;
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
}

.header p {
  font-size: 1.2rem;
  max-width: 700px;
  margin: 0 auto;
  position: relative;
}

.note {
  background: white;
  color: var(--text);
  padding: 15px;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  max-width: 800px;
  margin: -30px auto 60px;
  position: relative;
  text-align: center;
  font-weight: bold;
}

.nav {
  display: flex;
  justify-content: center;
  margin-bottom: 40px;
  flex-wrap: wrap;
}

.nav a {
  color: var(--text);
  text-decoration: none;
  margin: 0 15px;
  padding: 10px 20px;
  border-radius: 30px;
  transition: var(--transition);
  font-weight: 500;
  position: relative;
}

.nav a:hover {
  color: #8A2BE2;
}

.nav a::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 0;
  height: 2px;
  background: var(--accent);
  transition: var(--transition);
}

.nav a:hover::after {
  width: 60%;
}

article {
  background: white;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 40px;
  margin-bottom: 60px;
}

article h2 {
  color: #8A2BE2;
  margin-bottom: 30px;
  font-size: 2rem;
  position: relative;
  padding-bottom: 15px;
}

article h2::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 80px;
  height: 4px;
  background: var(--primary);
  border-radius: 2px;
}

article h3 {
  color: #FF7F50;
  margin: 30px 0 20px;
  font-size: 1.5rem;
}

article p {
  margin-bottom: 20px;
  font-size: 1.1rem;
}

pre {
  background: #2C3E50;
  color: #F8F9FA;
  padding: 20px;
  border-radius: 8px;
  overflow-x: auto;
  margin: 25px 0;
  font-size: 0.95rem;
  line-height: 1.6;
  position: relative;
}

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

.gallery {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 20px;
  margin: 40px 0;
}

.gallery img {
  width: 100%;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: var(--transition);
}

.gallery img:hover {
  transform: translateY(-5px);
  box-shadow: 0 15px 30px rgba(0, 0, 0, 0.15);
}

table {
  width: 100%;
  border-collapse: collapse;
  margin: 30px 0;
  box-shadow: var(--shadow);
  border-radius: var(--radius);
  overflow: hidden;
}

th, td {
  padding: 15px;
  text-align: left;
  border-bottom: 1px solid #eee;
}

th {
  background: #8A2BE2;
  color: white;
  font-weight: 500;
}

tr:nth-child(even) {
  background: #f9f9f9;
}

tr:hover {
  background: #f1f1f1;
}

.footer {
  text-align: center;
  padding: 40px 0;
  background: var(--primary);
  color: white;
  margin-top: 60px;
}

.footer p {
  max-width: 600px;
  margin: 0 auto;
}

@media (max-width: 768px) {
  .header h1 {
    font-size: 2.2rem;
  }
  
  .header p {
    font-size: 1rem;
  }
  
  article {
    padding: 30px 20px;
  }
  
  .nav a {
    margin: 5px;
    padding: 8px 15px;
  }
  
  .gallery {
    grid-template-columns: 1fr;
  }
}

@keyframes float {
  0%, 100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-10px);
  }
}

.decorative {
  position: absolute;
  width: 100px;
  height: 100px;
  background: url('https://images.gptkong.com/demo/sample5.png') no-repeat center/contain;
  opacity: 0.7;
  animation: float 4s ease-in-out infinite;
  z-index: -1;
}

.decorative-1 {
  top: 20%;
  left: 5%;
}

.decorative-2 {
  bottom: 10%;
  right: 5%;
}

.decorative-3 {
  top: 40%;
  right: 10%;
}

.highlight-box {
  background: linear-gradient(135deg, rgba(255, 127, 80, 0.1) 0%, rgba(138, 43, 226, 0.1) 100%);
  border-left: 4px solid #8A2BE2;
  padding: 20px;
  margin: 30px 0;
  border-radius: 0 var(--radius) var(--radius) 0;
}

.highlight-box h4 {
  color: #8A2BE2;
  margin-bottom: 10px;
}

.expandable {
  margin: 30px 0;
}

.expandable-title {
  background: #f1f1f1;
  padding: 15px;
  border-radius: var(--radius);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-weight: 500;
}

.expandable-content {
  padding: 20px;
  background: white;
  border-radius: 0 0 var(--radius) var(--radius);
  box-shadow: var(--shadow);
  display: none;
}

.expandable.active .expandable-content {
  display: block;
}