:root {
  --primary: #a8e6cf;
  --primary-dark: #2E8B57;
  --secondary: #dcedc1;
  --accent: #1E90FF;
  --accent-alt: #FFA500;
  --text: #333;
  --light: #F5F5F5;
  --shadow: 0 4px 20px 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 {
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  font-family: 'Roboto', sans-serif;
  color: var(--text);
  line-height: 1.6;
  min-height: 100%;
  overflow-x: hidden;
}

.header {
  text-align: center;
  padding: 2rem 0;
  position: relative;
  overflow: hidden;
}

.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: -1;
}

.header h1 {
  font-family: 'Pacifico', cursive;
  font-size: 3rem;
  color: var(--primary-dark);
  margin-bottom: 1rem;
  text-shadow: 2px 2px 4px rgba(0,0,0,0.1);
}

.header p {
  font-size: 1.2rem;
  max-width: 800px;
  margin: 0 auto;
  padding: 0 1rem;
}

.notice {
  background: rgba(255,255,255,0.9);
  padding: 1rem;
  border-radius: 8px;
  margin: 2rem auto;
  max-width: 800px;
  text-align: center;
  box-shadow: var(--shadow);
  border-left: 5px solid var(--accent);
}

.navbar {
  position: sticky;
  top: 0;
  width: 100%;
  background-color: var(--light);
  color: var(--primary-dark);
  display: flex;
  justify-content: center;
  padding: 1rem 0;
  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
  z-index: 1000;
}

.nav-container {
  width: 100%;
  max-width: 1200px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 2rem;
}

.nav-links {
  display: flex;
  gap: 2rem;
}

.navbar a {
  color: var(--primary-dark);
  text-decoration: none;
  padding: 0.5rem 1rem;
  transition: var(--transition);
  border-radius: 4px;
  font-weight: 500;
}

.navbar a:hover {
  background-color: var(--accent);
  color: white;
}

.hamburger {
  display: none;
  cursor: pointer;
}

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

.article-container {
  background: rgba(255,255,255,0.9);
  border-radius: 12px;
  padding: 2rem;
  margin-bottom: 2rem;
  box-shadow: var(--shadow);
  transition: var(--transition);
}

.article-container:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 30px rgba(0,0,0,0.15);
}

article h2 {
  font-family: 'Pacifico', cursive;
  color: var(--primary-dark);
  margin: 2rem 0 1rem;
  font-size: 2rem;
  position: relative;
  padding-bottom: 0.5rem;
}

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

article p {
  margin-bottom: 1.5rem;
  font-size: 1.1rem;
}

.color-sample {
  display: inline-block;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  vertical-align: middle;
  margin: 0 5px;
  box-shadow: 0 2px 5px rgba(0,0,0,0.2);
}

pre {
  background: #282c34;
  color: #abb2bf;
  padding: 1.5rem;
  border-radius: 8px;
  overflow-x: auto;
  margin: 1.5rem 0;
  box-shadow: var(--shadow);
  position: relative;
}

pre::before {
  content: "CSS";
  position: absolute;
  top: 0;
  left: 0;
  background: var(--accent);
  color: white;
  padding: 0.2rem 0.8rem;
  border-radius: 0 0 8px 0;
  font-size: 0.8rem;
}

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

.image-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}

.image-card {
  background: white;
  border-radius: 12px;
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: var(--transition);
}

.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;
  transition: var(--transition);
}

.image-card:hover img {
  transform: scale(1.05);
}

.image-caption {
  padding: 1rem;
  text-align: center;
  background: white;
}

.footer {
  text-align: center;
  padding: 2rem;
  background: rgba(255,255,255,0.8);
  margin-top: 2rem;
  border-radius: 12px 12px 0 0;
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
    flex-direction: column;
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    background: var(--light);
    padding: 1rem;
    box-shadow: 0 5px 10px rgba(0,0,0,0.1);
  }
  
  .nav-links.active {
    display: flex;
  }
  
  .hamburger {
    display: block;
  }
  
  .header h1 {
    font-size: 2rem;
  }
  
  article h2 {
    font-size: 1.5rem;
  }
}

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

.module {
  animation: fadeIn 0.8s ease-out forwards;
}

.module:nth-child(2) { animation-delay: 0.2s; }
.module:nth-child(3) { animation-delay: 0.4s; }
.module:nth-child(4) { animation-delay: 0.6s; }