/* Reset default margin and padding */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Segoe UI', sans-serif;
  background: #f2f4f8;
  color: #2c3e50;
  line-height: 1.6;
}

/* Header with gradient */
header {
  background: linear-gradient(to right, #0f2027, #203a43, #2c5364);
  color: #fff;
  text-align: center;
  padding: 2rem 1rem;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
}

header h1 {
  font-size: 2.5rem;
  margin-bottom: 0.5rem;
}

header p {
  font-size: 1.2rem;
  color: #d1d9e6;
}

/* Navigation bar */
nav {
  background: #1c2833;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.2);
}

nav ul {
  list-style: none;
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
}

nav ul li {
  margin: 0.5rem 1rem;
}

nav ul li a {
  color: #ffffff;
  text-decoration: none;
  font-weight: 600;
  padding: 0.5rem 1rem;
  transition: background 0.3s ease, color 0.3s ease;
  border-radius: 6px;
}

nav ul li a:hover {
  background: #f1c40f;
  color: #2c3e50;
}

/* Main content */
main {
  max-width: 1100px;
  margin: 2rem auto;
  padding: 2rem;
  background: #ffffff;
  border-radius: 12px;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.05);
}

section {
  margin-bottom: 3rem;
  padding: 1rem;
  border-left: 6px solid #2980b9;
  background: #fdfefe;
  border-radius: 8px;
  transition: transform 0.2s ease;
}

section:hover {
  transform: translateY(-5px);
  box-shadow: 0 6px 15px rgba(0, 0, 0, 0.08);
}

h2 {
  font-size: 1.8rem;
  color: #2980b9;
  margin-bottom: 1rem;
  border-bottom: 2px solid #eee;
  padding-bottom: 0.3rem;
}

ul {
  padding-left: 1.5rem;
}

ul li {
  margin-bottom: 0.6rem;
  font-size: 1.05rem;
}

/* Code styling */
code {
  background: #ecf0f1;
  padding: 0.2rem 0.4rem;
  font-family: 'Courier New', Courier, monospace;
  border-radius: 5px;
  color: #c0392b;
}

/* Footer */
footer {
  text-align: center;
  background: #2c3e50;
  color: #ecf0f1;
  padding: 1rem;
  font-size: 0.9rem;
  margin-top: 2rem;
  border-top: 4px solid #f1c40f;
}