当你不应用一些预定义的 CSS 规则时,它基本上会发生。为什么预定义是因为一些浏览器呈现自己的样式,比如边距应该是 1px 等,所以你必须用你自己的 CSS 规则覆盖它。是的,Levi Botelho 给出你是正确的答案。只要你要在 css 的帮助下描述 html 内容,只需包含以下规则。
/**
* 1.0 Reset
*
* Modified from Normalize.css to provide cross-browser consistency and a smart
* default styling of HTML elements.
*
* @see http://git.io/normalize
* ----------------------------------------------------------------------------
*/
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, i, center, dl, dt, dd, ol, ul, li,
fieldset, form, label, legend,
table, caption, tbody, tfoot, thead, tr, th, td,
article, aside, audio, canvas, details, figcaption,
figure, footer, header, hgroup, mark, menu, meter, nav,
output, progress, section, summary, time, video {
margin: 0;
padding: 0;
border: 0;
outline: 0;
font-size: 100%;
vertical-align: baseline;
background: transparent;
}
body {
line-height: 1;
}
article, aside, dialog, figure, footer, header,
hgroup, nav, section, blockquote {
display: block;
}
nav ul {
list-style: none;
}
ol {
list-style: decimal;
}
ul {
list-style: disc;
}
ul ul {
list-style: circle;
}
blockquote, q {
quotes: none;
}
blockquote:before, blockquote:after,
q:before, q:after {
content: '';
content: none;
}
ins {
text-decoration: underline;
}
del {
text-decoration: line-through;
}
mark {
background: none;
}
abbr[title], dfn[title] {
border-bottom:1px dotted #000;
cursor:help;
}
/* tables still need 'cellspacing="0"' in the markup */
table {
border-collapse: collapse;
border-spacing: 0;
}
hr {
display: block;
height: 1px;
border: 0;
border-top: 1px solid #ccc;
margin: 1em 0;
padding: 0;
}
input[type="submit"], input[type="button"], button {
padding: 0 !important;
margin: 0 !important;
}
input, select, a img {
vertical-align: middle;
}
/*
--------------------------------------------------------------------
End of reset css properties
--------------------------------------------------------------------
*/
希望得到答案!