移除postcss-reset (#35)

* remove postcss reset

packages/vant-css/src/reset.css

@@ -1,4 +1,46 @@
-@reset-global mobile;
+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, 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, article, aside, canvas, details, embed, figure, figcaption, footer, header, hgroup, menu, nav, output, ruby, section, summary, time, mark, audio, video {
+    margin: 0;
+    padding: 0;
+    border: 0;
+    font: inherit;
+    font-size: 100%;
+    vertical-align: baseline
+}
+
+html {
+    line-height: 1
+}
+
+ol, ul {
+    list-style: none
+}
+
+table {
+    border-collapse: collapse;
+    border-spacing: 0
+}
+
+caption, th, td {
+    font-weight: normal;
+    vertical-align: middle
+}
+
+q, blockquote {
+    quotes: none
+}
+
+q:before, q:after, blockquote:before, blockquote:after {
+    content: "";
+    content: none
+}
+
+a img {
+    border: none
+}
+
+article, aside, details, figcaption, figure, footer, header, hgroup, menu, nav, section, summary {
+    display: block
+}
 
 * {
   box-sizing: content-box;
@@ -22,7 +64,6 @@ input[type='number'],input[type='text'],input[type='password'],input[type='email
 select,
 textarea {
   font-family: inherit;
-  font-size: 100%;
   margin: 0;
   -webkit-tap-highlight-color: rgba(0, 0, 0, 0);
   -webkit-appearance: none;