:root {
    --primary-color: #1a365d;
    --secondary-color: #2b6cb0;
    --text-color: #333333;
    --bg-color: #f7fafc;
    --white: #ffffff;
    --font-main: 'Helvetica Neue', Helvetica, Arial, sans-serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: var(--font-main); color: var(--text-color); background-color: var(--bg-color); line-height: 1.6; }
.container { width: 90%; max-width: 1000px; margin: 0 auto; padding: 0 20px; }
header { background-color: var(--white); box-shadow: 0 2px 4px rgba(0,0,0,0.1); padding: 20px 0; position: sticky; top: 0; z-index: 100; }
.nav-container { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; }
.logo { font-size: 1.5rem; font-weight: bold; color: var(--primary-color); text-decoration: none; }
nav ul { list-style: none; display: flex; gap: 20px; }
nav a { text-decoration: none; color: var(--text-color); font-weight: 500; transition: color 0.3s ease; }
nav a:hover, nav a.active { color: var(--secondary-color); }
main { padding: 60px 0; min-height: 70vh; }
h1 { color: var(--primary-color); font-size: 2.5rem; margin-bottom: 20px; }
h2 { color: var(--primary-color); font-size: 1.8rem; margin: 30px 0 15px 0; }
h3 { color: var(--secondary-color); margin: 20px 0 10px 0; }
p { margin-bottom: 20px; font-size: 1.1rem; }
ul { margin: 0 0 20px 20px; font-size: 1.1rem; }
ul li { margin-bottom: 10px; }
.box { background: var(--white); padding: 30px; border-radius: 8px; box-shadow: 0 2px 5px rgba(0,0,0,0.05); margin-bottom: 30px; }
footer { background-color: var(--primary-color); color: var(--white); text-align: center; padding: 30px 0; margin-top: 40px; }
@media (max-width: 768px) {
    .nav-container { flex-direction: column; gap: 15px; }
    nav ul { flex-wrap: wrap; justify-content: center; }
}