The interface leans emotional rather than clinical, and every visual decision reinforces that. A serif display typeface gives headlines a warm, editorial quality, while a clean sans-serif keeps labels, values, and supporting text highly legible — a pairing that balances feeling with function. The pastel palette is more than decoration: menstrual pink, follicular blue, ovulatory yellow, and luteal lavender form a consistent phase-based color system that carries meaning across the phase indicator, the symptom heatmap, and the charts. The watercolor backdrop softens the whole experience without competing with content, and rounded cards, generous spacing, and gentle shadows keep even data-heavy screens feeling calm. A single dark floating navigation bar anchors the palette, providing just enough contrast to keep the primary actions grounded and easy to find.