:root {
  font-family: Inter, "Segoe UI", Arial, sans-serif;
  color: #33495a;
  background: #f5f7f9;
  font-synthesis: none;
}
* { box-sizing: border-box; }
html, body { width: 100%; height: 100%; margin: 0; min-width: 320px; }
button { font: inherit; }
[hidden] { display: none !important; }
.app-shell { display: flex; flex-direction: column; height: 100vh; height: 100dvh; min-height: 430px; overflow: hidden; }