/* Base Styles */
:root {
    --primary-color: #4a6fa5;
    --secondary-color: #166088;
    --accent-color: #4fc3f7;
    --text-color: #333;
    --bg-color: #f5f5f5;
    --header-bg: #fff;
    --nav-link-color: #4a6fa5;
    --control-btn-bg: #4a6fa5;
    --control-btn-text: #fff;
    --section-bg: #fff;
    --border-color: #ddd;
    --shadow-color: rgba(0, 0, 0, 0.1);
}

* {
    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(--bg-color);
    transition: all 0.3s ease;
}

header {
    background-color: var(--header-bg);
    padding: 1rem;
    box-shadow: 0 2px 10px var(--shadow-color);
    position: sticky;
    top: 0;
    z-index: 100;
}

.app-title {
    font-size: 1.8rem;
    margin-bottom: 0.5rem;
    color: var(--primary-color);
}

.main-nav ul {
    display: flex;
    list-style: none;
    gap: 1rem;
    margin-bottom: 1rem;
}

.nav-link {
    color: var(--nav-link-color);
    text-decoration: none;
    padding: 0.5rem 1rem;
    border-radius: 4px;
    transition: background-color 0.2s;
}

.nav-link:hover, .nav-link:focus {
    background-color: var(--accent-color);
    color: white;
    outline: 2px solid var(--primary-color);
}

.controls {
    display: flex;
    gap: 1rem;
    align-items: center;
    flex-wrap: wrap;
}

.control-btn {
    background-color: var(--control-btn-bg);
    color: var(--control-btn-text);
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 4px;
    cursor: pointer;
    transition: opacity 0.2s;
}

.control-btn:hover, .control-btn:focus {
    opacity: 0.8;
    outline: 2px solid var(--secondary-color);
}

.language-switcher {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.lang-btn {
    background: none;
    border: 1px solid var(--border-color);
    padding: 0.3rem 0.6rem;
    cursor: pointer;
    border-radius: 4px;
}

.lang-btn.active {
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

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

.section {
    background-color: var(--section-bg);
    border-radius: 8px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: 0 2px 5px var(--shadow-color);
}

.section h2 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.5rem;
}

.canvas-container {
    width: 100%;
    height: 400px;
    margin: 1rem 0;
    border: 1px solid var(--border-color);
    border-radius: 4px;
}

canvas {
    width: 100%;
    height: 100%;
    display: block;
}

button {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 0.6rem 1.2rem;
    border-radius: 4px;
    cursor: pointer;
    margin: 0.5rem 0;
    transition: background-color 0.2s;
}

button:hover, button:focus {
    background-color: var(--secondary-color);
    outline: 2px solid var(--accent-color);
}

footer {
    text-align: center;
    padding: 1rem;
    background-color: var(--header-bg);
    margin-top: 2rem;
}

/* Responsive design */
@media (max-width: 768px) {
    .main-nav ul {
        flex-wrap: wrap;
    }
    
    .controls {
        flex-direction: column;
        align-items: stretch;
    }
    
    main {
        padding: 1rem;
    }
    
    .section {
        padding: 1rem;
    }
}