:root {
    --primary-color: #2980b9;
    --secondary-color: #2c3e50;
    --accent-color: #e67e22;
    --bg-color: #f8f9fa;
    --text-color: #34495e;
    --white: #ffffff;
    --border-radius: 10px;
    --shadow: 0 4px 15px rgba(0,0,0,0.05);
    --font-main: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

body {
    font-family: var(--font-main);
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.8;
    margin: 0;
    padding: 0;
}

.nav-bar {
    background-color: var(--secondary-color);
    color: var(--white);
    padding: 1.5rem 3rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.nav-bar a {
    color: var(--white);
    text-decoration: none;
    margin-left: 1.5rem;
    font-weight: 600;
    transition: color 0.3s ease;
}

.nav-bar a:hover {
    color: var(--accent-color);
}

.container {
    max-width: 800px;
    margin: 3rem auto;
    padding: 3rem;
    background: var(--white);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    border: 1px solid rgba(0,0,0,0.05);
}

h1, h2, h3 {
    color: var(--secondary-color);
    margin-top: 2rem;
    margin-bottom: 1rem;
    font-weight: 700;
}

h1 { font-size: 2.5rem; }
h2 { font-size: 1.8rem; }
h3 { font-size: 1.4rem; }

p, ul, li {
    margin-bottom: 1.2rem;
}

.nav-links {
    text-align: right;
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid #eee;
}

.next-button {
    display: inline-block;
    background-color: var(--primary-color);
    color: var(--white);
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    text-decoration: none;
    font-weight: 600;
    transition: background-color 0.3s ease, transform 0.2s ease;
}

.next-button:hover {
    background-color: var(--secondary-color);
    transform: translateY(-2px);
}