line spacing css
/* Keyword value */
line-height: normal;
/* Unitless values: use this number multiplied
by the element's font size */
line-height: 3.5;
/* <length> values */
line-height: 3em;
/* <percentage> values */
line-height: 34%;
/* Global values */
line-height: inherit;
line-height: initial;
line-height: unset;
/* Valeur avec un mot-clé */
line-height: normal;
/* Type <number> */
/* S'il n'y a pas d'unité, cela
représente un facteur multiplicateur
de la taille de la police appliquée à
l'élément */
line-height: 3.5;
/* Valeur de longueur */
/* Type <length> */
line-height: 3em;
/* Valeurs proportionnelles */
/* Type <percentage> */
line-height: 34%;
/* Valeurs globales */
line-height: inherit;
line-height: initial;
line-height: unset;
<div class="box green">
<h1>Avoid unexpected results by using unitless line-height.</h1>
length and percentage line-heights have poor inheritance behavior ...
</div>
<div class="box red">
<h1>Avoid unexpected results by using unitless line-height.</h1>
length and percentage line-heights have poor inheritance behavior ...
</div>
<!-- The first <h1> line-height is calculated from its own font-size (30px × 1.1) = 33px -->
<!-- The second <h1> line-height results from the red div's font-size (15px × 1.1) = 16.5px, probably not what you want -->