:root {
  --primary: #2c3e50;
  --secondary: #3498db;
  --accent: #e74c3c;
  --light: #ecf0f1;
  --dark: #1a252f;
  --text: #333333;
  --bg-gradient: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
}

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

body {
  font-family: 'Roboto', sans-serif;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg-gradient);
  padding: 0;
  margin: 0;
  overflow-x: hidden;
}

.header {
  background: rgba(44, 62, 80, 0.9);
  backdrop-filter: blur(10px);
  padding: 1.5rem 5%;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--light);
  text-decoration: none;
  display: flex;
  align-items: center;
}

.logo span {
  color: var(--secondary);
}

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

.nav-link {
  color: var(--light);
  text-decoration: none;
  font-weight: 500;
  font-size: 1.1rem;
  position: relative;
  transition: all 0.3s ease;
}

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

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

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

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem 5%;
}

.hero {
  min-height: 60vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: 4rem 0;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: radial-gradient(circle at 70% 30%, rgba(52, 152, 219, 0.1) 0%, transparent 50%);
  z-index: -1;
}

.hero-title {
  font-size: 3.5rem;
  font-weight: 700;
  margin-bottom: 1.5rem;
  color: var(--primary);
  line-height: 1.2;
}

.hero-subtitle {
  font-size: 1.5rem;
  color: var(--primary);
  opacity: 0.8;
  margin-bottom: 2rem;
  max-width: 800px;
}

.notice {
  background: rgba(255, 255, 255, 0.9);
  padding: 1rem 2rem;
  border-radius: 50px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
  font-size: 0.9rem;
  color: var(--primary);
  margin-top: 2rem;
  display: inline-block;
}

.article {
  background: white;
  border-radius: 20px;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
  padding: 3rem;
  margin: 3rem 0;
}

.article h2 {
  font-size: 2.2rem;
  color: var(--primary);
  margin-bottom: 1.5rem;
  position: relative;
  padding-bottom: 0.5rem;
}

.article h2::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 80px;
  height: 4px;
  background: linear-gradient(90deg, var(--secondary), var(--accent));
  border-radius: 2px;
}

.article h3 {
  font-size: 1.8rem;
  color: var(--primary);
  margin: 2rem 0 1rem;
}

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

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

.image-card {
  border-radius: 15px;
  overflow: hidden;
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
  transition: all 0.3s ease;
}

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

.image-card img {
  width: 100%;
  height: auto;
  display: block;
  transition: transform 0.5s ease;
}

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

pre {
  background: #f8f9fa;
  border-radius: 10px;
  padding: 1.5rem;
  overflow-x: auto;
  margin: 2rem 0;
  border-left: 4px solid var(--secondary);
  font-size: 0.9rem;
  line-height: 1.6;
}

code {
  font-family: 'Courier New', monospace;
  color: #333;
}

.footer {
  background: var(--primary);
  color: var(--light);
  padding: 3rem 5%;
  text-align: center;
  margin-top: 3rem;
}

.footer-content {
  max-width: 800px;
  margin: 0 auto;
}

.footer p {
  margin-bottom: 1rem;
}

.scroll-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 50px;
  height: 50px;
  background: var(--secondary);
  color: white;
  border-radius: 50%;
  display: flex;
  justify-content: center;
  align-items: center;
  cursor: pointer;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
  transition: all 0.3s ease;
  opacity: 0;
  visibility: hidden;
}

.scroll-top.active {
  opacity: 1;
  visibility: visible;
}

.scroll-top:hover {
  background: var(--accent);
  transform: translateY(-5px);
}

@media (max-width: 768px) {
  .header {
    flex-direction: column;
    padding: 1rem;
  }
  
  .nav {
    margin-top: 1rem;
    flex-wrap: wrap;
    justify-content: center;
  }
  
  .hero-title {
    font-size: 2.5rem;
  }
  
  .hero-subtitle {
    font-size: 1.2rem;
  }
  
  .article {
    padding: 2rem;
  }
  
  .article h2 {
    font-size: 1.8rem;
  }
  
  .article h3 {
    font-size: 1.5rem;
  }
}

@keyframes float {
  0%, 100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-20px);
  }
}

.floating {
  animation: float 6s ease-in-out infinite;
}