:root {
  --primary-color: #0F4C81;
  --secondary-color: #1A6FC9;
  --accent-orange: #FFA500;
  --accent-green: #32CD32;
  --light-bg: #F5F9FF;
  --dark-text: #1E1E1E;
  --light-text: #FFFFFF;
  --border-radius: 12px;
  --box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
  --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

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

body {
  font-family: 'Roboto', 'Helvetica', sans-serif;
  line-height: 1.6;
  color: var(--dark-text);
  background: linear-gradient(135deg, var(--light-bg) 0%, #FFFFFF 100%);
  min-height: 100%;
  overflow-x: hidden;
}

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

.header {
  text-align: center;
  margin-bottom: 3rem;
  position: relative;
}

.header::after {
  content: "";
  display: block;
  width: 120px;
  height: 4px;
  background: linear-gradient(90deg, var(--accent-orange), var(--accent-green));
  margin: 1.5rem auto;
  border-radius: 2px;
}

h1, h2, h3, h4 {
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 1.5rem;
  color: var(--primary-color);
}

h1 {
  font-size: 2.5rem;
  background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

h2 {
  font-size: 2rem;
  position: relative;
  padding-bottom: 0.5rem;
}

h2::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 60px;
  height: 3px;
  background: var(--accent-orange);
  border-radius: 3px;
}

h3 {
  font-size: 1.5rem;
  margin-top: 2rem;
  color: var(--secondary-color);
}

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

.article-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 3rem;
}

.article-section {
  background: white;
  border-radius: var(--border-radius);
  padding: 2.5rem;
  box-shadow: var(--box-shadow);
  transition: var(--transition);
}

.article-section:hover {
  transform: translateY(-5px);
  box-shadow: 0 12px 28px rgba(0, 0, 0, 0.15);
}

.code-block {
  background: #282C34;
  color: #ABB2BF;
  padding: 1.5rem;
  border-radius: var(--border-radius);
  margin: 1.5rem 0;
  overflow-x: auto;
  font-family: 'Fira Code', monospace;
  font-size: 0.9rem;
  line-height: 1.5;
  position: relative;
}

.code-block::before {
  content: "CSS";
  position: absolute;
  top: 0;
  right: 0;
  background: var(--accent-green);
  color: white;
  padding: 0.25rem 0.75rem;
  border-radius: 0 0 0 var(--border-radius);
  font-size: 0.8rem;
}

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

.image-card {
  border-radius: var(--border-radius);
  overflow: hidden;
  box-shadow: var(--box-shadow);
  transition: var(--transition);
  position: relative;
}

.image-card:hover {
  transform: scale(1.03);
}

.image-card img {
  width: 100%;
  height: auto;
  display: block;
  transition: var(--transition);
}

.notice {
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  color: white;
  padding: 1rem;
  border-radius: var(--border-radius);
  margin: 2rem 0;
  text-align: center;
  box-shadow: var(--box-shadow);
}

.nav-links {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 1rem;
  margin: 2rem 0;
}

.nav-link {
  background: var(--primary-color);
  color: white;
  padding: 0.75rem 1.5rem;
  border-radius: 50px;
  text-decoration: none;
  transition: var(--transition);
  font-weight: 500;
}

.nav-link:hover {
  background: var(--secondary-color);
  transform: translateY(-2px);
}

@media (max-width: 768px) {
  .container {
    padding: 1.5rem;
  }
  
  h1 {
    font-size: 2rem;
  }
  
  h2 {
    font-size: 1.75rem;
  }
  
  .article-section {
    padding: 1.5rem;
  }
}

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

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