:root {
    --primary-color: #4a90e2;
    --secondary-color: #2c3e50;
    --background-color: #f5f6fa;
    --text-color: #333;
}

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

body {
    font-family: 'Arial', sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--background-color);
}

header {
    background-color: white;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
}

nav {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

nav ul {
    display: flex;
    list-style: none;
}

nav ul li {
    margin-left: 2rem;
}

nav a {
    text-decoration: none;
    color: var(--secondary-color);
    font-weight: 500;
}

main {
    margin-top: 80px;
    padding: 2rem;
}

.hero {
    text-align: center;
    padding: 4rem 0;
}

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.solver-container {
    max-width: 1000px;
    margin: 2rem auto;
    background: white;
    padding: 1rem;
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.instructions {
    max-width: 1200px;
    margin: 4rem auto;
    padding: 2rem;
}

.steps {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.step {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.faq {
    max-width: 800px;
    margin: 4rem auto;
}

.faq-container details {
    background: white;
    padding: 1rem;
    margin-bottom: 1rem;
    border-radius: 5px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.faq-container summary {
    cursor: pointer;
    font-weight: 500;
    color: var(--primary-color);
}

footer {
    text-align: center;
    padding: 2rem;
    background: var(--secondary-color);
    color: white;
    margin-top: 4rem;
}

@media (max-width: 768px) {
    nav {
        flex-direction: column;
        text-align: center;
    }

    nav ul {
        margin-top: 1rem;
    }

    nav ul li {
        margin: 0 1rem;
    }

    .hero h1 {
        font-size: 2rem;
    }
}