:root {
  --primary: #0074D9;
  --secondary: #2ECC40;
  --accent: #FF851B;
  --bg-light: #F5F5F5;
  --text-dark: #333333;
  --white: #FFFFFF;
}

@import url('https://fonts.googleapis.com/css2?family=Roboto:wght@400;700&display=swap');

body {
  font-family: 'Roboto', sans-serif;
  background: radial-gradient(circle at 10% 20%, rgba(245, 245, 245, 0.9), rgba(255, 255, 255, 1));
  color: var(--text-dark);
  margin: 0;
  padding: 0;
  line-height: 1.6;
}

.header {
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  padding: 2rem 0;
  text-align: center;
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
  position: relative;
  overflow: hidden;
}

.header::before {
  content: "";
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, rgba(255,255,255,0) 70%);
  transform: rotate(45deg);
  animation: shine 8s infinite linear;
}

@keyframes shine {
  0% { transform: translateX(-100%) rotate(45deg); }
  100% { transform: translateX(100%) rotate(45deg); }
}

.header h1 {
  color: var(--white);
  font-size: 2.5rem;
  margin: 0;
  text-shadow: 0 2px 4px rgba(0,0,0,0.2);
  position: relative;
}

.notice {
  background: rgba(255,255,255,0.2);
  padding: 0.5rem;
  border-radius: 4px;
  display: inline-block;
  margin-top: 1rem;
  font-size: 0.9rem;
  backdrop-filter: blur(5px);
}

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

.nav-tabs {
  display: flex;
  justify-content: center;
  margin-bottom: 3rem;
  flex-wrap: wrap;
  gap: 1rem;
}

.nav-tab {
  padding: 0.8rem 1.5rem;
  background: var(--white);
  border-radius: 50px;
  color: var(--primary);
  font-weight: 700;
  text-decoration: none;
  box-shadow: 0 4px 6px rgba(0,0,0,0.1);
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
  border: none;
  cursor: pointer;
}

.nav-tab::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: var(--accent);
  transform: scaleX(0);
  transition: transform 0.3s ease;
}

.nav-tab:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 12px rgba(0,0,0,0.15);
}

.nav-tab:hover::after {
  transform: scaleX(1);
}

.article-container {
  background: var(--white);
  border-radius: 12px;
  box-shadow: 0 10px 30px rgba(0,0,0,0.08);
  padding: 3rem;
  margin-bottom: 3rem;
}

.article-container h2 {
  color: var(--primary);
  font-size: 1.8rem;
  margin-top: 2.5rem;
  position: relative;
  padding-bottom: 0.5rem;
}

.article-container h2::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 60px;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
  border-radius: 2px;
}

.article-container h3 {
  color: var(--secondary);
  font-size: 1.4rem;
  margin-top: 2rem;
}

.article-container p {
  font-size: 1.1rem;
  margin: 1.5rem 0;
}

.color-swatch {
  display: inline-block;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  margin-right: 5px;
  vertical-align: middle;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

table {
  width: 100%;
  border-collapse: collapse;
  margin: 2rem 0;
  background: var(--white);
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

table thead th {
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: var(--white);
  padding: 1rem;
  text-align: left;
}

table tbody td {
  padding: 1.5rem;
  border-bottom: 1px solid rgba(0,0,0,0.05);
}

pre {
  background: #2d2d2d;
  color: #f8f8f2;
  padding: 1.5rem;
  border-radius: 8px;
  overflow-x: auto;
  font-family: 'Courier New', Courier, monospace;
  font-size: 0.95rem;
  line-height: 1.5;
  margin: 0;
}

code {
  font-family: 'Courier New', Courier, monospace;
  background: rgba(0,0,0,0.05);
  padding: 0.2rem 0.4rem;
  border-radius: 4px;
  font-size: 0.9rem;
}

.image-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 2rem;
  margin: 3rem 0;
}

.image-card {
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 8px 20px rgba(0,0,0,0.1);
  transition: all 0.3s ease;
  position: relative;
}

.image-card:hover {
  transform: translateY(-10px);
  box-shadow: 0 15px 30px rgba(0,0,0,0.15);
}

.image-card img {
  width: 100%;
  height: 300px;
  object-fit: cover;
  display: block;
}

.footer {
  text-align: center;
  padding: 2rem;
  color: var(--text-dark);
  font-size: 0.9rem;
  opacity: 0.8;
}

@media (max-width: 768px) {
  .header h1 {
    font-size: 2rem;
  }
  
  .article-container {
    padding: 2rem;
  }
  
  .image-grid {
    grid-template-columns: 1fr;
  }
}

.active {
  color: var(--accent);
  font-weight: bold;
}