CSS:Reset CSS หรือ base stylesheet

/* v1.0 | 20080212 */
<style>
html, body, div, span, applet, object, iframe,
h1, h2, h3, h4, h5, h6, p, blockquote, pre,
a, abbr, acronym, address, big, cite, code,
del, dfn, em, font, img, ins, kbd, q, s, samp,
small, strike, strong, sub, sup, tt, var,
b, u, i, center,
dl, dt, dd, ol, ul, li,
fieldset, form, label, legend,
table, caption, tbody, tfoot, thead, tr, th, td {
        margin: 0;
        padding: 0;
        border: 0;
        outline: 0;
        font-size: 100%;
        vertical-align: baseline;
        background: transparent;
}
body {
        line-height: 1;
}
ol, ul {
        list-style: none;
}
blockquote, q {
        quotes: none;
}
blockquote:before, blockquote:after,
q:before, q:after {
        content: '';
        content: none;
}

/* remember to define focus styles! */
:focus {
        outline: 0;
}

/* remember to highlight inserts somehow! */
ins {
        text-decoration: none;
}
del {
        text-decoration: line-through;
}

/* tables still need 'cellspacing="0"' in the markup */
table {
        border-collapse: collapse;
        border-spacing: 0;
}
</style>