CSS template

style.css

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
  height: 100vw;
  width: 100vw;
}

body {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  font-family: -apple-system, ".SFNSText-Regular", "San Francisco", "Roboto", "Segoe UI", "Helvetica Neue", "Lucida Grande", sans-serif;
}

.wrapper {
  width: 100%;
  max-width: 960px;
}