:root {
  --primary-blue: #123456;
  --primary-purple: #7845AB;
  --accent-orange: #FFA500;
  --background-white: #FFFFFF;
  --background-gray: #EFEFEF;
  --text-dark: #333333;
  --text-light: #777777;
  --shadow-sm: 0 2px 8px rgba(0,0,0,0.1);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.15);
  --shadow-lg: 0 8px 24px rgba(0,0,0,0.2);
  --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

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

body {
  font-family: 'Helvetica Neue', Arial, sans-serif;
  line-height: 1.6;
  color: var(--text-dark);
  background-color: var(--background-white);
  overflow-x: hidden;
}

.header {
  background: linear-gradient(135deg, var(--primary-blue), var(--primary-purple));
  color: white;
  padding: 2rem 0;
  text-align: center;
  position: relative;
  overflow: hidden;
  margin-bottom: 3rem;
}

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

.header-content {
  position: relative;
  z-index: 1;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
}

.header h1 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  text-shadow: 0 2px 4px rgba(0,0,0,0.3);
}

.header p {
  font-size: 1.2rem;
  max-width: 800px;
  margin: 0 auto 2rem;
}

.notice {
  background-color: var(--accent-orange);
  color: white;
  padding: 0.5rem 1rem;
  border-radius: 4px;
  display: inline-block;
  font-weight: bold;
  margin-top: 1rem;
  box-shadow: var(--shadow-sm);
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin-bottom: 3rem;
}

.card {
  background: white;
  border-radius: 8px;
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-md);
}

.card-img {
  height: 200px;
  background-size: cover;
  background-position: center;
}

.card-content {
  padding: 1.5rem;
}

.card h3 {
  color: var(--primary-purple);
  margin-bottom: 0.5rem;
}

.card p {
  color: var(--text-light);
  margin-bottom: 1rem;
}

.article-container {
  max-width: 900px;
  margin: 0 auto 4rem;
  padding: 2rem;
  background: white;
  border-radius: 8px;
  box-shadow: var(--shadow-sm);
}

article h2 {
  color: var(--primary-purple);
  margin: 2rem 0 1rem;
  font-size: 1.8rem;
  position: relative;
  padding-bottom: 0.5rem;
}

article h2::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 60px;
  height: 3px;
  background: linear-gradient(90deg, var(--primary-blue), var(--primary-purple));
}

article h3 {
  color: var(--primary-blue);
  margin: 1.5rem 0 1rem;
  font-size: 1.4rem;
}

article h4 {
  color: var(--primary-blue);
  margin: 1.2rem 0 0.8rem;
  font-size: 1.2rem;
}

article p {
  margin-bottom: 1.2rem;
  font-size: 1.05rem;
  line-height: 1.7;
}

article strong {
  color: var(--primary-blue);
}

article em {
  font-style: italic;
  color: var(--primary-purple);
}

.highlight {
  color: var(--accent-orange);
  font-weight: bold;
}

pre {
  background: #f5f7fa;
  border-radius: 6px;
  padding: 1.2rem;
  margin: 1.5rem 0;
  overflow-x: auto;
  box-shadow: var(--shadow-sm);
  border-left: 4px solid var(--primary-purple);
}

code {
  font-family: 'Courier New', monospace;
  font-size: 0.9rem;
  color: #333;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  box-shadow: var(--shadow-sm);
}

th, td {
  padding: 0.8rem 1rem;
  text-align: left;
  border-bottom: 1px solid #eee;
}

th {
  background-color: var(--primary-blue);
  color: white;
}

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

tr:hover {
  background-color: #f1f1f1;
}

.gallery {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 1rem;
  margin: 2rem 0;
}

.gallery-item {
  border-radius: 8px;
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

.gallery-item:hover {
  transform: scale(1.03);
  box-shadow: var(--shadow-md);
}

.gallery-item img {
  width: 100%;
  height: auto;
  display: block;
}

.nav-tabs {
  display: flex;
  border-bottom: 1px solid #ddd;
  margin-bottom: 1.5rem;
}

.nav-tabs a {
  padding: 0.8rem 1.5rem;
  text-decoration: none;
  color: var(--text-dark);
  border-bottom: 3px solid transparent;
  transition: var(--transition);
}

.nav-tabs a:hover {
  color: var(--primary-purple);
}

.nav-tabs a.active {
  color: var(--primary-purple);
  border-bottom-color: var(--primary-purple);
  font-weight: bold;
}

.footer {
  background: linear-gradient(135deg, var(--primary-blue), var(--primary-purple));
  color: white;
  padding: 2rem 0;
  text-align: center;
  margin-top: 3rem;
}

.footer p {
  margin-bottom: 0.5rem;
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: 1.5rem;
  margin-top: 1rem;
}

.footer-links a {
  color: white;
  text-decoration: none;
  transition: var(--transition);
}

.footer-links a:hover {
  color: var(--accent-orange);
}

@media (max-width: 768px) {
  .header h1 {
    font-size: 2rem;
  }
  
  .header p {
    font-size: 1rem;
  }
  
  .grid {
    grid-template-columns: 1fr;
  }
  
  .article-container {
    padding: 1.5rem;
  }
  
  article h2 {
    font-size: 1.6rem;
  }
  
  article h3 {
    font-size: 1.3rem;
  }
}

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

.floating {
  animation: float 3s ease-in-out infinite;
}