:root {
    /* Colors */
    --color-bg: #fafafa;
    --color-surface: #ffffff;
    --color-border: #e0e0e0;
    --color-border-light: #f0f0f0;
    --color-text-primary: #1a1a1a;
    --color-text-secondary: #666666;
    --color-text-muted: #999999;

    /* Priority Colors */
    --priority-low: #4caf50;
    --priority-low-bg: #e8f5e9;
    --priority-medium: #ff9800;
    --priority-medium-bg: #fff3e0;
    --priority-high: #f44336;
    --priority-high-bg: #ffebee;

    /* UI Colors */
    --color-primary: #2196f3;
    --color-primary-hover: #1976d2;
    --color-danger: #f44336;
    --color-danger-hover: #d32f2f;
    --color-success: #4caf50;

    /* Focus States */
    --color-focus-ring: rgba(33, 150, 243, 0.4);

    /* Spacing */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;

    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-full: 9999px;

    /* Shadows */
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 250ms ease;

    /* Typography */
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    --font-size-sm: 13px;
    --font-size-base: 15px;
    --font-size-lg: 17px;
    --font-size-xl: 24px;

    /* Layout */
    --max-width: 600px;
    --header-height: 60px;
}

/* Dark Mode Support */
@media (prefers-color-scheme: dark) {
    :root {
        --color-bg: #121212;
        --color-surface: #1e1e1e;
        --color-border: #333333;
        --color-border-light: #2a2a2a;
        --color-text-primary: #ffffff;
        --color-text-secondary: #b0b0b0;
        --color-text-muted: #707070;

        --priority-low-bg: rgba(76, 175, 80, 0.15);
        --priority-medium-bg: rgba(255, 152, 0, 0.15);
        --priority-high-bg: rgba(244, 67, 54, 0.15);
    }
}