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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    background: #f5f5f5;
}

.main-container {
    max-width: 1200px;
    margin: 0 auto;
    background: #fff;
    box-shadow: 0 0 20px rgba(0,0,0,0.1);
}

header {
    background: linear-gradient(135deg, #2c3e50 0%, #34495e 100%);
    color: #fff;
    padding: 2rem 2rem 1.5rem;
    border-bottom: 4px solid #e74c3c;
}

h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    font-weight: 700;
    text-align: center;
}

article {
    padding: 3rem 2rem;
    background: #fff;
}

article h2 {
    color: #2c3e50;
    margin: 2rem 0 1rem;
    font-size: 1.8rem;
    border-left: 4px solid #e74c3c;
    padding-left: 1rem;
}

article h3 {
    color: #34495e;
    margin: 1.5rem 0 0.8rem;
    font-size: 1.4rem;
}

article h4 {
    color: #555;
    margin: 1.2rem 0 0.6rem;
    font-size: 1.2rem;
}

article p {
    margin-bottom: 1rem;
    color: #555;
    font-size: 1.05rem;
}

article ul, article ol {
    margin: 1rem 0 1rem 2rem;
}

article li {
    margin-bottom: 0.5rem;
    color: #555;
}

.transition-section {
    padding: 2rem;
    background: #ecf0f1;
    border-top: 2px solid #bdc3c7;
    border-bottom: 2px solid #bdc3c7;
}

.transition-section p {
    color: #555;
    font-size: 1.05rem;
    line-height: 1.7;
    margin-bottom: 1rem;
}

.links-section {
    padding: 3rem 2rem;
    background: #f9f9f9;
}

.links-section h2 {
    color: #2c3e50;
    margin-bottom: 2rem;
    font-size: 2rem;
    text-align: center;
    border: none;
    padding: 0;
}

.links-section h3 {
    color: #34495e;
    margin: 2rem 0 1rem;
    font-size: 1.5rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid #e74c3c;
}

.links-section ul {
    list-style: none;
    margin: 0 0 2rem 0;
    padding: 0;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 0.8rem 2rem;
}

.links-section li {
    margin: 0;
}

.links-section a {
    color: #2980b9;
    text-decoration: none;
    transition: color 0.3s ease;
    display: inline-block;
    padding: 0.3rem 0;
}

.links-section a:hover {
    color: #e74c3c;
    text-decoration: underline;
}

footer {
    background: #2c3e50;
    color: #ecf0f1;
    padding: 2rem;
    text-align: center;
    border-top: 4px solid #e74c3c;
}

footer p {
    margin: 0.5rem 0;
    font-size: 0.95rem;
}

@media (max-width: 768px) {
    h1 {
        font-size: 2rem;
    }

    header {
        padding: 1.5rem 1rem 1rem;
    }

    article {
        padding: 2rem 1rem;
    }

    article h2 {
        font-size: 1.5rem;
    }

    article h3 {
        font-size: 1.2rem;
    }

    .transition-section {
        padding: 1.5rem 1rem;
    }

    .links-section {
        padding: 2rem 1rem;
    }

    .links-section h2 {
        font-size: 1.6rem;
    }

    .links-section h3 {
        font-size: 1.3rem;
    }

    .links-section ul {
        grid-template-columns: 1fr;
        gap: 0.6rem;
    }

    footer {
        padding: 1.5rem 1rem;
    }
}

@media (max-width: 480px) {
    h1 {
        font-size: 1.6rem;
    }

    article h2 {
        font-size: 1.3rem;
    }

    article p {
        font-size: 1rem;
    }

    .links-section h2 {
        font-size: 1.4rem;
    }
}