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

body {
  font-family: 'Arial', sans-serif;
  line-height: 1.6;
  color: #333;
  background-color: #f4f4f4;
}

header {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  padding: 1rem 0;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

nav {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 2rem;
}

nav h1 {
  font-size: 1.8rem;
  font-weight: bold;
}

nav ul {
  display: flex;
  list-style: none;
  gap: 2rem;
}

nav a {
  color: white;
  text-decoration: none;
  font-weight: 500;
  transition: color 0.3s ease;
}

nav a:hover {
  color: #ffd700;
}

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

.hero {
  text-align: center;
  padding: 4rem 0;
  background: white;
  border-radius: 10px;
  margin-bottom: 3rem;
  box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

.hero h2 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  color: #333;
}

.hero p {
  font-size: 1.2rem;
  color: #666;
}

.articles-section h2 {
  text-align: center;
  margin-bottom: 2rem;
  font-size: 2rem;
  color: #333;
}

.articles-container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  gap: 2rem;
  margin-bottom: 3rem;
}

.article-card {
  background: white;
  border-radius: 10px;
  padding: 1.5rem;
  box-shadow: 0 5px 15px rgba(0,0,0,0.1);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  cursor: pointer;
}

.article-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 25px rgba(0,0,0,0.15);
}

.article-card h3 {
  color: #667eea;
  margin-bottom: 0.5rem;
  font-size: 1.3rem;
}

.article-card .meta {
  color: #888;
  font-size: 0.9rem;
  margin-bottom: 1rem;
}

.article-card p {
  color: #666;
  line-height: 1.6;
  margin-bottom: 1rem;
}

.article-card .tags {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.tag {
  background: #e3f2fd;
  color: #1976d2;
  padding: 0.3rem 0.8rem;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 500;
}

.search-section {
  background: white;
  padding: 2rem;
  border-radius: 10px;
  box-shadow: 0 5px 15px rgba(0,0,0,0.1);
  text-align: center;
  margin-bottom: 2rem;
}

.search-section h3 {
  margin-bottom: 1rem;
  color: #333;
}

#searchInput {
  padding: 0.8rem;
  border: 2px solid #ddd;
  border-radius: 5px;
  width: 300px;
  margin-right: 1rem;
  font-size: 1rem;
}

#searchInput:focus {
  outline: none;
  border-color: #667eea;
}

#searchBtn {
  padding: 0.8rem 1.5rem;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  border: none;
  border-radius: 5px;
  cursor: pointer;
  font-size: 1rem;
  transition: opacity 0.3s ease;
}

#searchBtn:hover {
  opacity: 0.9;
}

footer {
  background: #333;
  color: white;
  text-align: center;
  padding: 2rem 0;
  margin-top: 3rem;
}

.hidden {
  display: none;
}

@media (max-width: 768px) {
  nav {
    flex-direction: column;
    gap: 1rem;
  }

  nav ul {
    gap: 1rem;
  }

  .hero h2 {
    font-size: 2rem;
  }

  .articles-container {
    grid-template-columns: 1fr;
  }

  #searchInput {
    width: 100%;
    margin-right: 0;
    margin-bottom: 1rem;
  }

  main {
    padding: 1rem;
  }
}