:root {
  --primary-color: #003366;
  --secondary-color: #ffffff;
  --accent-color: linear-gradient(45deg, #ff7e5f, #feb47b);
  --shadow: 0 10px 30px rgba(0, 51, 102, 0.2);
  --border-radius: 16px;
  --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}
body {
  font-family: 'Segoe UI', Roboto, sans-serif;
  line-height: 1.8;
  color: #333;
  background: linear-gradient(135deg, #f5f7fa 0%, #e4e8eb 100%);
  margin: 0;
  padding: 0;
}
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 40px 20px;
}
.header {
  text-align: center;
  margin-bottom: 60px;
  position: relative;
}
.header::after {
  content: "";
  display: block;
  width: 100px;
  height: 4px;
  background: var(--accent-color);
  margin: 20px auto;
  border-radius: 2px;
}
h1, h2, h3, h4 {
  color: var(--primary-color);
  font-weight: 700;
}
h1 { font-size: 2.8rem; margin-bottom: 20px; }
h2 { font-size: 2.2rem; margin: 50px 0 30px; }
h3 { font-size: 1.8rem; margin: 40px 0 20px; }
p {
  font-size: 1.1rem;
  margin-bottom: 25px;
  color: #444;
}
.card {
  background: white;
  border-radius: var(--border-radius);
  box-shadow: var(--shadow);
  padding: 30px;
  margin-bottom: 40px;
  transition: var(--transition);
}
.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 15px 35px rgba(0, 51, 102, 0.25);
}
.img-container {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  margin: 40px 0;
  justify-content: center;
}
.img-wrapper {
  width: 320px;
  height: 320px;
  border-radius: var(--border-radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: var(--transition);
}
.img-wrapper:hover {
  transform: scale(1.03);
}
.img-wrapper img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
pre {
  background: #2d2d2d;
  color: #f8f8f2;
  padding: 20px;
  border-radius: 8px;
  overflow-x: auto;
  margin: 30px 0;
  font-size: 0.95rem;
  line-height: 1.5;
}
code {
  font-family: 'Fira Code', monospace;
}
.notice {
  background: var(--primary-color);
  color: white;
  padding: 15px 25px;
  border-radius: var(--border-radius);
  margin: 40px 0;
  text-align: center;
  font-size: 1.2rem;
  box-shadow: var(--shadow);
}
.grid-layout {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(500px, 1fr));
  gap: 30px;
  margin: 50px 0;
}
.flex-layout {
  display: flex;
  flex-wrap: wrap;
  gap: 30px;
  margin: 50px 0;
}
.flex-item {
  flex: 1 1 500px;
  min-width: 0;
}
.parallax-effect {
  height: 400px;
  background-attachment: fixed;
  background-position: center;
  background-repeat: no-repeat;
  background-size: cover;
  margin: 60px 0;
  border-radius: var(--border-radius);
  position: relative;
  overflow: hidden;
}
.parallax-effect::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(to right, rgba(0,51,102,0.8), rgba(0,51,102,0.5));
}
@media (max-width: 768px) {
  .grid-layout {
    grid-template-columns: 1fr;
  }
  h1 { font-size: 2.2rem; }
  h2 { font-size: 1.8rem; }
  h3 { font-size: 1.5rem; }
  .parallax-effect {
    background-attachment: scroll;
  }
}
@keyframes float {
  0% { transform: translateY(0px); }
  50% { transform: translateY(-15px); }
  100% { transform: translateY(0px); }
}
.floating {
  animation: float 3s ease-in-out infinite;
}