pixel to rem conversion
html {
/* 62.5% of 16px base font size is 10px */
font-size: 62.5%;
}
/* Preserve 16px body font-size, set body font-size to 1.6rem */
body {
/* 16px */
font-size: 1.6rem;
}
.some-element {
/* 10 * 1.2 = 12px */
font-size: 1.2rem;
}