:root {
  --primary: #0F4C81;
  --secondary: #FFA500;
  --bg-gradient: linear-gradient(135deg, #E0F7FA 0%, #FFFFFF 100%);
  --text-dark: #333;
  --text-light: #fff;
  --accent: #d63384;
  --gray-light: #f4f4f4;
  --shadow: 0 4px 20px rgba(0,0,0,0.1);
}

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

body {
  background: var(--bg-gradient);
  color: var(--text-dark);
  font-family: 'Roboto', sans-serif;
  line-height: 1.6;
  padding-top: 80px;
}

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

.header {
  text-align: center;
  margin-bottom: 60px;
  position: relative;
}

.header::after {
  content: "";
  display: block;
  width: 100px;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
  margin: 20px auto;
  border-radius: 2px;
}

.navbar {
  background-color: var(--primary);
  position: fixed;
  top: 0;
  width: 100%;
  padding: 15px 0;
  z-index: 1000;
  box-shadow: var(--shadow);
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

.logo {
  color: var(--text-light);
  font-size: 1.5rem;
  font-weight: 700;
  text-decoration: none;
}

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

.nav-links a {
  color: var(--text-light);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.3s;
  position: relative;
}

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

.nav-links a::after {
  content: "";
  position: absolute;
  bottom: -5px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--secondary);
  transition: width 0.3s;
}

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

.banner {
  background: linear-gradient(rgba(15, 76, 129, 0.8), rgba(15, 76, 129, 0.8)), 
              url('https://images.gptkong.com/demo/sample1.png');
  background-size: cover;
  background-position: center;
  height: 400px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  text-align: center;
  margin-bottom: 60px;
  border-radius: 10px;
  box-shadow: var(--shadow);
}

.banner-content {
  max-width: 800px;
  padding: 0 20px;
}

.banner h1 {
  font-size: 2.5rem;
  margin-bottom: 20px;
  text-shadow: 0 2px 4px rgba(0,0,0,0.3);
}

.banner p {
  font-size: 1.2rem;
  margin-bottom: 30px;
}

.notice {
  background: rgba(255,255,255,0.2);
  padding: 15px 30px;
  border-radius: 50px;
  font-size: 0.9rem;
  display: inline-block;
  backdrop-filter: blur(5px);
}

article {
  background: white;
  padding: 40px;
  border-radius: 10px;
  box-shadow: var(--shadow);
  margin-bottom: 60px;
}

article h2 {
  color: var(--primary);
  font-family: 'Great Vibes', cursive;
  font-size: 2.2rem;
  margin-bottom: 30px;
  position: relative;
}

article h2::after {
  content: "";
  position: absolute;
  bottom: -10px;
  left: 0;
  width: 100px;
  height: 3px;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
}

article h3 {
  color: var(--primary);
  font-size: 1.5rem;
  margin: 30px 0 20px;
  position: relative;
}

article h3::before {
  content: "";
  position: absolute;
  bottom: -5px;
  left: 0;
  width: 50px;
  height: 2px;
  background: var(--secondary);
}

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

.color-box {
  display: inline-block;
  width: 20px;
  height: 20px;
  border-radius: 3px;
  vertical-align: middle;
  margin: 0 5px;
  box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 30px;
  margin: 40px 0;
}

.grid-item {
  background: var(--gray-light);
  padding: 20px;
  border-radius: 8px;
  transition: transform 0.3s, box-shadow 0.3s;
}

.grid-item:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 20px rgba(0,0,0,0.1);
}

.grid-img {
  width: 100%;
  height: 200px;
  object-fit: cover;
  border-radius: 5px;
  margin-bottom: 15px;
  box-shadow: 0 4px 10px rgba(0,0,0,0.1);
}

pre {
  background: #2d2d2d;
  padding: 20px;
  border-radius: 8px;
  margin: 20px 0;
  overflow-x: auto;
  color: #f8f8f2;
  font-family: 'Courier New', monospace;
  font-size: 0.9rem;
  line-height: 1.5;
  position: relative;
}

pre::before {
  content: "CSS";
  position: absolute;
  top: 0;
  right: 0;
  background: var(--primary);
  color: white;
  padding: 3px 10px;
  font-size: 0.8rem;
  border-radius: 0 0 0 5px;
}

code {
  font-family: 'Courier New', monospace;
  color: var(--accent);
  background: rgba(214, 51, 132, 0.1);
  padding: 2px 5px;
  border-radius: 3px;
}

.gallery {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 20px;
  margin: 40px 0;
}

.gallery-item {
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 4px 10px rgba(0,0,0,0.1);
  transition: transform 0.3s;
}

.gallery-item:hover {
  transform: scale(1.03);
}

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

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

.footer p {
  margin-bottom: 20px;
}

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

.social-links a {
  color: white;
  font-size: 1.5rem;
  transition: color 0.3s;
}

.social-links a:hover {
  color: var(--secondary);
}

@media (max-width: 768px) {
  .grid {
    grid-template-columns: 1fr;
  }
  
  .nav-links {
    gap: 15px;
  }
  
  .banner h1 {
    font-size: 2rem;
  }
}

@media (max-width: 480px) {
  .nav-container {
    flex-direction: column;
    gap: 15px;
  }
  
  .banner {
    height: 300px;
  }
  
  article {
    padding: 20px;
  }
}

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

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

.pulse {
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% {
    box-shadow: 0 0 0 0 rgba(255, 165, 0, 0.7);
  }
  70% {
    box-shadow: 0 0 0 10px rgba(255, 165, 0, 0);
  }
  100% {
    box-shadow: 0 0 0 0 rgba(255, 165, 0, 0);
  }
}