:root {
  --primary: #1E3C72;
  --secondary: #2A5298;
  --accent: #FF9800;
  --text: #FFFFFF;
  --card-bg: rgba(255, 255, 255, 0.1);
  --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

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

body {
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  color: var(--text);
  font-family: 'Montserrat', 'Segoe UI', sans-serif;
  line-height: 1.6;
  padding-top: 80px;
}

.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background: rgba(30, 60, 114, 0.8);
  backdrop-filter: blur(10px);
  padding: 15px 5%;
  z-index: 1000;
  display: flex;
  justify-content: space-between;
  align-items: center;
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
}

.logo {
  font-size: 1.8rem;
  font-weight: 700;
  background: linear-gradient(45deg, #FF9800, #FFC107);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.nav-links {
  display: flex;
  gap: 30px;
}

.nav-links a {
  color: var(--text);
  text-decoration: none;
  font-weight: 500;
  position: relative;
  padding: 5px 0;
  transition: var(--transition);
}

.nav-links a:after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent);
  transition: var(--transition);
}

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

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

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

.hero {
  height: 500px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero: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: 0.2;
  z-index: -1;
}

.hero h1 {
  font-size: 3.5rem;
  margin-bottom: 20px;
  background: linear-gradient(45deg, #FFFFFF, #00FF7F);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  animation: fadeInUp 1s ease;
}

.hero p {
  font-size: 1.2rem;
  max-width: 700px;
  margin-bottom: 30px;
  opacity: 0;
  animation: fadeInUp 1s ease 0.3s forwards;
}

.notice {
  background: rgba(255, 255, 255, 0.15);
  padding: 15px;
  border-radius: 10px;
  margin: 30px auto;
  max-width: 800px;
  text-align: center;
  backdrop-filter: blur(5px);
  border: 1px solid rgba(255, 255, 255, 0.2);
}

article {
  max-width: 900px;
  margin: 50px auto;
  padding: 40px;
  background: var(--card-bg);
  backdrop-filter: blur(10px);
  border-radius: 20px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

article h2 {
  font-size: 2.2rem;
  margin-bottom: 30px;
  color: #00FF7F;
  position: relative;
  padding-bottom: 15px;
}

article h2:after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100px;
  height: 3px;
  background: linear-gradient(90deg, #00FF7F, transparent);
}

article h3 {
  font-size: 1.8rem;
  margin: 40px 0 20px;
  color: #FF9800;
}

article p {
  margin-bottom: 25px;
  font-size: 1.1rem;
}

pre {
  background: rgba(0, 0, 0, 0.3);
  border-radius: 10px;
  padding: 20px;
  margin: 25px 0;
  overflow-x: auto;
  position: relative;
  border-left: 4px solid var(--accent);
}

pre:before {
  content: 'CSS';
  position: absolute;
  top: 0;
  right: 0;
  background: var(--accent);
  color: #000;
  padding: 3px 10px;
  font-size: 0.8rem;
  border-bottom-left-radius: 5px;
}

code {
  font-family: 'Courier New', monospace;
  font-size: 0.95rem;
}

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

.image-card {
  background: var(--card-bg);
  border-radius: 15px;
  overflow: hidden;
  transition: var(--transition);
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.image-card:hover {
  transform: translateY(-10px);
  box-shadow: 0 15px 30px rgba(0, 0, 0, 0.2);
}

.image-card img {
  width: 100%;
  height: 200px;
  object-fit: cover;
  display: block;
}

.image-caption {
  padding: 15px;
  text-align: center;
}

.footer {
  text-align: center;
  padding: 30px;
  margin-top: 50px;
  background: rgba(0, 0, 0, 0.2);
}

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

@media (max-width: 768px) {
  .hero h1 {
    font-size: 2.5rem;
  }
  
  .nav-links {
    gap: 15px;
  }
  
  article {
    padding: 30px 20px;
  }
  
  .image-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 480px) {
  .header {
    flex-direction: column;
    padding: 15px;
  }
  
  .nav-links {
    margin-top: 15px;
    flex-wrap: wrap;
    justify-content: center;
  }
  
  .hero h1 {
    font-size: 2rem;
  }
}