client/src/index.css

:root {
  font-family: "Source Sans Pro", sans-serif;
  line-height: 1.5;
  font-weight: 400;
  color-scheme: light dark;
  background-color: #f5f5f5;
  font-synthesis: none;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

html,
body,
#root {
  width: 100%;
  min-height: 100vh;
  font-family: "Source Sans Pro", sans-serif;
}

body {
  margin: 0;
  min-width: 320px;
}

@media (prefers-color-scheme: light) {
  :root {
    color: #213547;
    background-color: #f5f5f5;
  }
}