:root {
/* Base Typography Styles */
--font-main: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
--font-reader: system-ui;
--font-size-base: 16px;
--line-height-base: 1.6;

/* Theme Engine: Light (Default) */
--bg-primary: #ffffff;
--bg-surface: #f5f5f7;
--text-primary: #1d1d1f;
--text-secondary: #86868b;
--accent: #0071e3;
--touch-target: 48px;
}

[data-theme="dark"] {
--bg-primary: #000000;
--bg-surface: #1c1c1e;
--text-primary: #f5f5f7;
--text-secondary: #8e8e93;
--accent: #2997ff;
}

[data-theme="sepia"] {
--bg-primary: #f4ecd8;
--bg-surface: #e8dfc8;
--text-primary: #5b4636;
--text-secondary: #8f7865;
--accent: #8c6239;
}

[data-theme="high-contrast"] {
--bg-primary: #000000;
--bg-surface: #000000;
--text-primary: #ffffff;
--text-secondary: #ffff00;
--accent: #00ff00;
}