:root {
  --primary-color: #1E3A8A;
  --secondary-color: #10B981;
  --accent-color: #F97316;
  --background-color: #F5F5F5;
  --text-color: #333333;
  --card-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
  --transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

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

body {
  background: linear-gradient(135deg, #f5f7fa 0%, #e4e8f0 100%);
  color: var(--text-color);
  font-family: 'Helvetica Neue', Arial, sans-serif;
  line-height: 1.6;
  padding-top: 80px;
}

.header-notice {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background: var(--primary-color);
  color: white;
  text-align: center;
  padding: 12px;
  font-size: 14px;
  z-index: 1001;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

.hero {
  background: linear-gradient(135deg, rgba(30, 58, 138, 0.9) 0%, rgba(16, 185, 129, 0.8) 100%);
  color: white;
  padding: 60px 0;
  border-radius: 16px;
  margin: 30px 0;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::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%);
  animation: pulse 15s infinite linear;
}

@keyframes pulse {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

.hero h1 {
  font-size: 2.5rem;
  margin-bottom: 20px;
  position: relative;
  z-index: 1;
}

.hero p {
  max-width: 700px;
  margin: 0 auto 30px;
  font-size: 1.1rem;
  position: relative;
  z-index: 1;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 30px;
  margin: 40px 0;
}

.card {
  background: white;
  border-radius: 12px;
  padding: 30px;
  box-shadow: var(--card-shadow);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.card:hover {
  transform: translateY(-10px);
  box-shadow: 0 15px 35px rgba(0, 0, 0, 0.12);
}

.card::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(90deg, var(--secondary-color), var(--accent-color));
}

.card h2 {
  color: var(--primary-color);
  margin-bottom: 15px;
  font-size: 1.5rem;
}

.card p {
  margin-bottom: 20px;
}

.img-container {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  margin: 30px 0;
  justify-content: center;
}

.img-wrapper {
  width: 150px;
  height: 150px;
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
  transition: var(--transition);
}

.img-wrapper:hover {
  transform: scale(1.05);
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.15);
}

.img-wrapper img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

pre {
  background: #2d2d2d;
  color: #f8f8f2;
  padding: 20px;
  border-radius: 8px;
  overflow-x: auto;
  margin: 20px 0;
  font-size: 0.9rem;
  line-height: 1.5;
  position: relative;
}

pre::before {
  content: "CSS";
  position: absolute;
  top: 0;
  left: 0;
  background: var(--accent-color);
  color: white;
  padding: 2px 10px;
  border-radius: 0 0 4px 0;
  font-size: 0.8rem;
}

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

article {
  background: white;
  border-radius: 12px;
  padding: 40px;
  box-shadow: var(--card-shadow);
  margin: 40px 0;
}

article h2 {
  color: var(--primary-color);
  font-size: 2rem;
  margin-bottom: 20px;
  position: relative;
  padding-bottom: 10px;
}

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

article h3 {
  color: var(--secondary-color);
  font-size: 1.5rem;
  margin: 30px 0 15px;
}

article p {
  margin-bottom: 20px;
  font-size: 1.1rem;
}

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

.nav-links {
  display: flex;
  justify-content: center;
  margin: 30px 0;
  flex-wrap: wrap;
  gap: 15px;
}

.nav-link {
  padding: 10px 20px;
  background: var(--primary-color);
  color: white;
  border-radius: 30px;
  text-decoration: none;
  transition: var(--transition);
  font-weight: 500;
}

.nav-link:hover {
  background: var(--secondary-color);
  transform: translateY(-3px);
}

@media (max-width: 768px) {
  .hero h1 {
    font-size: 2rem;
  }
  
  .hero p {
    font-size: 1rem;
  }
  
  article {
    padding: 25px;
  }
  
  article h2 {
    font-size: 1.8rem;
  }
  
  article h3 {
    font-size: 1.3rem;
  }
}

@media (max-width: 480px) {
  .grid {
    grid-template-columns: 1fr;
  }
  
  .img-wrapper {
    width: 120px;
    height: 120px;
  }
}