:root {
  --primary-color: #0A74DA;
  --accent-color: #FF7F50;
  --background-color: #F5F5F5;
  --text-color: #333;
  --light-gray: #eaeaea;
  --dark-gray: #555;
  --gradient-blue: linear-gradient(135deg, #0A74DA 0%, #00B4DB 100%);
  --gradient-orange: linear-gradient(135deg, #FF7F50 0%, #FF6347 100%);
  --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);
  --border-radius: 12px;
  --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

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

body {
  font-family: 'Open Sans', sans-serif;
  line-height: 1.6;
  color: var(--text-color);
  background-color: var(--background-color);
  padding: 0;
  margin: 0;
  overflow-x: hidden;
}

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

.header {
  background: var(--gradient-blue);
  color: white;
  padding: 20px 0;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-md);
}

.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;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 24px;
  font-weight: 700;
  letter-spacing: 1px;
}

.nav {
  display: flex;
  gap: 20px;
}

.nav a {
  color: white;
  text-decoration: none;
  font-weight: 600;
  padding: 8px 12px;
  border-radius: 4px;
  transition: var(--transition);
  position: relative;
}

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

.nav a:hover::after {
  width: 100%;
}

.banner {
  background: var(--gradient-orange);
  padding: 60px 0;
  text-align: center;
  color: white;
  position: relative;
  margin-bottom: 40px;
  clip-path: polygon(0 0, 100% 0, 100% 90%, 0 100%);
}

.banner h1 {
  font-size: 42px;
  margin-bottom: 20px;
  text-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

.banner p {
  font-size: 18px;
  max-width: 700px;
  margin: 0 auto 30px;
}

.notice {
  background: white;
  padding: 15px;
  border-radius: var(--border-radius);
  margin: 20px auto;
  max-width: 800px;
  text-align: center;
  box-shadow: var(--shadow-sm);
  border-left: 4px solid var(--accent-color);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% { transform: scale(1); }
  50% { transform: scale(1.02); }
  100% { transform: scale(1); }
}

article {
  background: white;
  padding: 40px;
  border-radius: var(--border-radius);
  box-shadow: var(--shadow-sm);
  margin: 40px 0;
}

article h2 {
  color: var(--primary-color);
  font-size: 32px;
  margin-bottom: 30px;
  position: relative;
  padding-bottom: 15px;
}

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

article h3 {
  color: var(--dark-gray);
  font-size: 24px;
  margin: 30px 0 20px;
}

article p {
  margin-bottom: 20px;
  font-size: 16px;
}

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

pre {
  background: #282c34;
  color: #abb2bf;
  padding: 20px;
  border-radius: var(--border-radius);
  margin: 20px 0;
  overflow-x: auto;
  box-shadow: var(--shadow-sm);
  font-family: 'Courier New', monospace;
  font-size: 14px;
  line-height: 1.5;
}

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

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

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

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

.gallery-item img {
  width: 100%;
  height: 200px;
  object-fit: cover;
  transition: var(--transition);
}

.gallery-item:hover img {
  transform: scale(1.05);
}

.gallery-caption {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  background: rgba(0,0,0,0.7);
  color: white;
  padding: 15px;
  transform: translateY(100%);
  transition: var(--transition);
}

.gallery-item:hover .gallery-caption {
  transform: translateY(0);
}

.card-container {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 30px;
  margin: 40px 0;
}

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

.card:hover {
  transform: translateY(-10px);
  box-shadow: var(--shadow-lg);
}

.card-img {
  height: 200px;
  overflow: hidden;
}

.card-img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: var(--transition);
}

.card:hover .card-img img {
  transform: scale(1.1);
}

.card-body {
  padding: 20px;
}

.card-title {
  font-size: 20px;
  margin-bottom: 10px;
  color: var(--primary-color);
}

.card-text {
  color: var(--dark-gray);
  margin-bottom: 15px;
}

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

.footer-links {
  display: flex;
  justify-content: center;
  gap: 20px;
  margin-bottom: 20px;
}

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

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

@media (max-width: 768px) {
  .header-content {
    flex-direction: column;
    gap: 20px;
  }
  
  .nav {
    flex-direction: column;
    gap: 10px;
    align-items: center;
  }
  
  .banner h1 {
    font-size: 32px;
  }
  
  article {
    padding: 20px;
  }
  
  .gallery {
    grid-template-columns: 1fr;
  }
  
  .card-container {
    grid-template-columns: 1fr;
  }
}

/* Animation classes */
@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes slideInLeft {
  from { transform: translateX(-50px); opacity: 0; }
  to { transform: translateX(0); opacity: 1; }
}

@keyframes slideInRight {
  from { transform: translateX(50px); opacity: 0; }
  to { transform: translateX(0); opacity: 1; }
}

.animate-fade {
  animation: fadeIn 1s ease forwards;
}

.animate-left {
  animation: slideInLeft 0.8s ease forwards;
}

.animate-right {
  animation: slideInRight 0.8s ease forwards;
}