/* Common styles for all pages */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-bg: #ffffff;
    --secondary-bg: #f5f5f5;
    --text-primary: #000000;
    --text-secondary: #666666;
    --border-color: #e0e0e0;
    --hover-bg: #f0f0f0;
    --transition: all 0.3s ease;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--primary-bg);
}

/* Header styles */
header {
    background-color: var(--primary-bg);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 1000;
}

.header-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    text-decoration: none;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.logo:hover {
    opacity: 0.8;
}

nav ul {
    display: flex;
    list-style: none;
    gap: 2rem;
}

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

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

.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-primary);
}

/* Main content */
main {
    min-height: calc(100vh - 200px);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

/* Footer styles */
footer {
    background-color: var(--secondary-bg);
    border-top: 1px solid var(--border-color);
    padding: 3rem 0 1rem;
    margin-top: 4rem;
}

.footer-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 3rem;
    margin-bottom: 2rem;
}

.footer-brand {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.footer-logo {
    font-size: 1.3rem;
    font-weight: bold;
    color: var(--text-primary);
}

.footer-description {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.footer-links h4 {
    margin-bottom: 1rem;
    font-size: 1rem;
}

.footer-links ul {
    list-style: none;
}

.footer-links li {
    margin-bottom: 0.5rem;
}

.footer-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    transition: var(--transition);
}

.footer-links a:hover {
    color: var(--text-primary);
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
    color: var(--text-secondary);
    font-size: 0.85rem;
}

/* Back to top button */
.back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 50px;
    height: 50px;
    background-color: var(--text-primary);
    color: var(--primary-bg);
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: none;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    transition: var(--transition);
    z-index: 999;
}

.back-to-top:hover {
    background-color: var(--text-secondary);
    transform: translateY(-5px);
}

.back-to-top.visible {
    display: flex;
}

/* Responsive design */
@media (max-width: 768px) {
    .header-container {
        padding: 0 1rem;
    }

    nav {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background-color: var(--primary-bg);
        border-bottom: 1px solid var(--border-color);
    }

    nav.active {
        display: block;
    }

    nav ul {
        flex-direction: column;
        gap: 0;
        height: 100vh;
        padding: 1rem;
    }

    nav li {
        padding: 0.5rem 0;
        border-bottom: 1px solid var(--border-color);
    }

    nav li:last-child {
        border-bottom: none;
    }

    .mobile-menu-toggle {
        display: block;
    }

    .container {
        padding: 1rem;
    }

    .footer-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .back-to-top {
        bottom: 1rem;
        right: 1rem;
        width: 45px;
        height: 45px;
    }
}