:root {
    --primary-color: #667eea;
    --primary-dark: #5a6fd8;
    --secondary-color: #764ba2;
    --success-color: #27ae60;
    --warning-color: #f39c12;
    --danger-color: #e74c3c;
    
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-tertiary: #e9ecef;
    --text-primary: #2c3e50;
    --text-secondary: #6c757d;
    --text-muted: #adb5bd;
    --border-color: #dee2e6;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 4px 20px rgba(0, 0, 0, 0.15);
    
    --border-radius: 8px;
    --border-radius-lg: 16px;
    --transition: all 0.3s ease;
    --max-width: 1200px;
}

[data-theme="dark"] {
    --bg-primary: #1a1a1a;
    --bg-secondary: #2d2d2d;
    --bg-tertiary: #404040;
    --text-primary: #ffffff;
    --text-secondary: #b0b0b0;
    --text-muted: #888888;
    --border-color: #404040;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
    --shadow-hover: 0 4px 20px rgba(0, 0, 0, 0.4);
}

@media (prefers-color-scheme: dark) {
    [data-theme="auto"] {
        --bg-primary: #1a1a1a;
        --bg-secondary: #2d2d2d;
        --bg-tertiary: #404040;
        --text-primary: #ffffff;
        --text-secondary: #b0b0b0;
        --text-muted: #888888;
        --border-color: #404040;
        --shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
        --shadow-hover: 0 4px 20px rgba(0, 0, 0, 0.4);
    }
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: var(--transition);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.container { max-width: var(--max-width); margin: 0 auto; padding: 0 1rem; }

.header {
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-content { display: flex; justify-content: space-between; align-items: center; }
.logo { display: flex; align-items: center; gap: 0.75rem; }
.logo-icon { font-size: 2rem; }
.logo h1 { font-size: 1.5rem; font-weight: 600; color: var(--primary-color); }
.header-controls { display: flex; align-items: center; gap: 1rem; }

.theme-toggle, .lang-toggle {
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 0.5rem;
    cursor: pointer;
    transition: var(--transition);
    color: var(--text-primary);
}

.theme-toggle:hover, .lang-toggle:hover { background: var(--border-color); }
.theme-icon { font-size: 1.2rem; }
.lang-toggle { font-weight: 600; min-width: 3rem; }

.main { flex: 1; padding: 2rem 0; }

.search-section { margin-bottom: 2rem; }
.search-container { position: relative; max-width: 500px; margin: 0 auto; }

.search-input {
    width: 100%;
    padding: 1rem 1rem 1rem 3rem;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-lg);
    background: var(--bg-secondary);
    color: var(--text-primary);
    font-size: 1rem;
    transition: var(--transition);
}

.search-input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.search-button {
    position: absolute; left: 1rem; top: 50%; transform: translateY(-50%);
    background: none; border: none; font-size: 1.2rem; cursor: pointer; color: var(--text-muted);
}

.categories-section { margin-bottom: 2rem; }
.category-filters { display: flex; justify-content: center; gap: 0.5rem; flex-wrap: wrap; }

.category-btn {
    padding: 0.75rem 1.5rem;
    border: 1px solid var(--border-color);
    background: var(--bg-secondary);
    color: var(--text-secondary);
    border-radius: var(--border-radius-lg);
    cursor: pointer;
    transition: var(--transition);
    font-weight: 500;
}

.category-btn:hover { background: var(--bg-tertiary); }
.category-btn.active { background: var(--primary-color); color: white; border-color: var(--primary-color); }

.files-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.file-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-lg);
    padding: 1.5rem;
    transition: var(--transition);
    cursor: pointer;
}

.file-card:hover { box-shadow: var(--shadow-hover); transform: translateY(-2px); }

.file-header { display: flex; align-items: center; gap: 1rem; margin-bottom: 1rem; }
.file-icon { font-size: 2.5rem; width: 3.5rem; height: 3.5rem; display: flex; align-items: center; justify-content: center; background: var(--bg-tertiary); border-radius: var(--border-radius); }

.file-info h3 { font-size: 1.1rem; font-weight: 600; color: var(--text-primary); margin-bottom: 0.25rem; }
.file-version { color: var(--text-muted); font-size: 0.9rem; }
.file-details { margin-bottom: 1rem; }
.file-size { color: var(--text-secondary); font-size: 0.9rem; margin-bottom: 0.5rem; }
.file-description { color: var(--text-muted); font-size: 0.85rem; line-height: 1.4; }
.file-actions { display: flex; gap: 0.5rem; }

.btn {
    padding: 0.5rem 1rem;
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-weight: 500;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 0.9rem;
}

.btn-primary { background: var(--primary-color); color: white; }
.btn-primary:hover { background: var(--primary-dark); }
.btn-secondary { background: var(--bg-tertiary); color: var(--text-primary); border: 1px solid var(--border-color); }
.btn-secondary:hover { background: var(--border-color); }

.empty-state { text-align: center; padding: 3rem 1rem; color: var(--text-muted); }
.empty-icon { font-size: 4rem; margin-bottom: 1rem; }
.empty-state h3 { margin-bottom: 0.5rem; color: var(--text-secondary); }

.footer { background: var(--bg-secondary); border-top: 1px solid var(--border-color); padding: 2rem 0; margin-top: auto; }
.footer-content { text-align: center; }
.footer-note { color: var(--text-muted); font-size: 0.9rem; margin-top: 0.5rem; }

.modal {
    position: fixed; top: 0; left: 0; width: 100%; height: 100%;
    background: rgba(0, 0, 0, 0.5); display: none; align-items: center; justify-content: center; z-index: 1000; padding: 1rem;
}

.modal.active { display: flex; }
.modal-content { background: var(--bg-primary); border-radius: var(--border-radius-lg); max-width: 400px; width: 100%; }
.modal-header { display: flex; justify-content: space-between; align-items: center; padding: 1.5rem 1.5rem 1rem; border-bottom: 1px solid var(--border-color); }
.modal-close { background: none; border: none; font-size: 1.5rem; cursor: pointer; color: var(--text-muted); }
.modal-body { padding: 1.5rem; }
.download-info { text-align: center; }
.download-info .file-icon { font-size: 3rem; margin: 0 auto 1rem; }
.download-warning { color: var(--warning-color); font-size: 0.9rem; margin-top: 1rem; }
.modal-footer { display: flex; gap: 0.5rem; padding: 1rem 1.5rem 1.5rem; }
.modal-footer .btn { flex: 1; }

@media (max-width: 768px) {
    .header-content { flex-direction: column; gap: 1rem; }
    .files-grid { grid-template-columns: 1fr; }
    .category-filters { overflow-x: auto; }
}

.lang-switching { opacity: 0; transition: opacity 0.2s ease; }