:root {
    --primary: #2c3e50;
    --secondary: #3498db;
    --accent: #e74c3c;
    --bg: #f4f7f6;
    --text: #333;
    --light-text: #ecf0f1;
    --white: #ffffff;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text);
    background-color: var(--bg);
}

header {
    background-color: var(--primary);
    color: var(--light-text);
    padding: 1.5rem 0;
    text-align: center;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

header h1 {
    margin-bottom: 1rem;
    font-size: 2rem;
}

nav {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 1rem;
    background: var(--white);
    padding: 1rem;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
}

nav a {
    text-decoration: none;
    color: var(--primary);
    font-weight: 600;
    padding: 0.5rem 1rem;
    border-radius: 4px;
    transition: background 0.3s, color 0.3s;
}

nav a:hover {
    background-color: var(--secondary);
    color: var(--white);
}

.container {
    max-width: 1000px;
    margin: 2rem auto;
    padding: 0 2rem;
}

section {
    background: var(--white);
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.05);
    margin-bottom: 2rem;
}

h2 {
    color: var(--primary);
    margin-bottom: 1rem;
    border-bottom: 2px solid var(--secondary);
    display: inline-block;
    padding-bottom: 0.3rem;
}

p {
    margin-bottom: 1rem;
}

footer {
    text-align: center;
    padding: 2rem 0;
    color: #777;
    font-size: 0.9rem;
}

.icon-logo {
    width: 50px;
    height: 50px;
    vertical-align: middle;
    margin-right: 10px;
}

.btn {
    display: inline-block;
    background: var(--secondary);
    color: var(--white);
    padding: 0.8rem 1.5rem;
    text-decoration: none;
    border-radius: 5px;
    transition: opacity 0.3s;
}

.btn:hover {
    opacity: 0.9;
}

.error-page {
    text-align: center;
    padding: 5rem 2rem;
}

.error-page h1 {
    font-size: 5rem;
    color: var(--accent);
}

@media (max-width: 600px) {
    nav {
        flex-direction: column;
        align-items: center;
    }
}