:root {
  --primary: linear-gradient(135deg, #1e3c72 0%, #2a5298 50%, #8e44ad 100%);
  --secondary: #2a5298;
  --accent: #8e44ad;
  --text: #333;
  --light: #f8f9fa;
  --dark: #212529;
  --gray: #7f8c8d;
  --border: rgba(255,255,255,0.2);
  --shadow: 0 10px 30px rgba(0,0,0,0.1);
  --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);
  background: var(--light);
  overflow-x: hidden;
}

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

.header {
  background: var(--primary);
  color: white;
  padding: 80px 0 120px;
  position: relative;
  overflow: hidden;
  clip-path: polygon(0 0, 100% 0, 100% 90%, 0 100%);
}

.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: 800px;
  margin: 0 auto;
  text-align: center;
}

.header h1 {
  font-size: 3rem;
  margin-bottom: 1.5rem;
  text-shadow: 0 2px 10px rgba(0,0,0,0.3);
}

.header p {
  font-size: 1.2rem;
  margin-bottom: 2rem;
  opacity: 0.9;
}

.notice {
  background: rgba(255,255,255,0.2);
  padding: 15px;
  border-radius: 8px;
  margin-top: 30px;
  font-size: 0.9rem;
  backdrop-filter: blur(5px);
}

.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background: rgba(255,255,255,0.95);
  box-shadow: 0 2px 15px rgba(0,0,0,0.1);
  z-index: 1000;
  padding: 15px 0;
  transition: var(--transition);
}

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

.nav-logo {
  font-size: 1.5rem;
  font-weight: bold;
  color: var(--secondary);
  text-decoration: none;
}

.nav-menu {
  display: flex;
  list-style: none;
}

.nav-item {
  margin-left: 30px;
  position: relative;
}

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

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

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

.main {
  padding: 100px 0;
}

.article {
  background: white;
  border-radius: 12px;
  box-shadow: var(--shadow);
  padding: 50px;
  margin-bottom: 60px;
}

.article h2 {
  font-size: 2rem;
  color: var(--secondary);
  margin-bottom: 1.5rem;
  position: relative;
  padding-bottom: 15px;
}

.article h2::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 60px;
  height: 3px;
  background: var(--accent);
}

.article h3 {
  font-size: 1.5rem;
  color: var(--secondary);
  margin: 2rem 0 1rem;
}

.article p {
  margin-bottom: 1.5rem;
  font-size: 1.1rem;
  line-height: 1.8;
}

.article pre {
  background: #282c34;
  color: #abb2bf;
  padding: 20px;
  border-radius: 8px;
  overflow-x: auto;
  margin: 2rem 0;
  box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

.article code {
  font-family: 'Fira Code', monospace;
  font-size: 0.9rem;
}

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

.grid-gallery {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 30px;
  margin: 3rem 0;
}

.gallery-item {
  border-radius: 12px;
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: var(--transition);
  position: relative;
}

.gallery-item:hover {
  transform: translateY(-10px);
  box-shadow: 0 15px 35px rgba(0,0,0,0.15);
}

.gallery-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.footer {
  background: var(--dark);
  color: white;
  padding: 60px 0 30px;
  text-align: center;
}

.footer-links {
  display: flex;
  justify-content: center;
  margin-bottom: 30px;
}

.footer-link {
  color: white;
  text-decoration: none;
  margin: 0 15px;
  transition: var(--transition);
}

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

.copyright {
  opacity: 0.7;
  font-size: 0.9rem;
}

@media (max-width: 768px) {
  .header h1 {
    font-size: 2.2rem;
  }
  
  .nav-menu {
    display: none;
  }
  
  .article {
    padding: 30px;
  }
  
  .grid-gallery {
    grid-template-columns: 1fr;
  }
}

@keyframes float {
  0%, 100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-15px);
  }
}

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