CSS3 Transitions属性打造动画的下载按钮特效

@font-face {
  font-family: ‘entypo‘;
  src: url(‘entypo/entypo.eot‘);
  src: url(‘entypo/entypo.eot?#iefix‘) format(‘embedded-opentype‘), 
       url(‘entypo/entypo.woff‘) format(‘woff‘),
       url(‘entypo/entypo.ttf‘)  format(‘truetype‘),
       url(‘entypo/entypo.svg#svgFontName‘) format(‘svg‘);
}

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-size: 100%;
  font: inherit;
  vertical-align: baseline;
  outline: none;
  -webkit-font-smoothing: antialiased;
  -webkit-text-size-adjust: 100%;
  -ms-text-size-adjust: 100%;
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  box-sizing: border-box;
}
html { overflow-y: scroll; }
body {
  font-family: ‘Helvetica‘, Arial, sans-serif;
  font-size: 62.5%;
  line-height: 1;
  color: #414141;
  margin: 45px 15px;
  background: #ececec url(‘bg.png‘);
}

br { display: block; margin: 10px 0;} 

article, aside, details, figcaption, figure, footer, header, hgroup, menu, nav, section { display: block; }
ol, ul { list-style: none; }

input, textarea { 
  -webkit-font-smoothing: antialiased;
  -webkit-text-size-adjust: 100%;
  -ms-text-size-adjust: 100%;
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  box-sizing: border-box;
  outline: none; 
}

blockquote, q { quotes: none; }
blockquote:before, blockquote:after, q:before, q:after { content: ‘‘; content: none; }
strong, b { font-weight: bold; }
em, i { font-style: italic; }

table { border-collapse: collapse; border-spacing: 0; }
img { border: 0; max-width: 100%; height: auto; width: 100%; }

h1 {
  font-size: 3.1em;
  line-height: 1.55em;
  text-align: center;
  font-weight: bold;
  font-family: ‘Oswald‘, ‘Helvetica‘, Arial, sans-serif;
  margin-bottom: 35px;
  color: #595959;
}

.entypo {
  font-family: ‘entypo‘, sans-serif;  
}


/** page structure **/
#wrapper {
  display: block;
  max-width: 850px;
  padding: 45px 35px;
  margin: 0 auto;
  background: #fff;
  -webkit-border-radius: 7px;
  -moz-border-radius: 7px;
  border-radius: 7px;
}

.center {
  width: 20%;
  margin: 0 auto;
}
.centerbig {
  width: 40%;
  margin: 0 auto;
}


/** download button effect **/
a.dlbtn {
  display: inline-block;
  position: relative;
  height: 45px;
  line-height: 40px;
  overflow: hidden;
  padding: 0 30px;
  font-size: 12px;
  font-weight: bold;
  color: #c0c0c0;
  background-color: #fff;
  text-decoration: none;
  cursor: pointer;
  border: 3px solid #ddd;
  -webkit-border-radius: 2px;
  -moz-border-radius: 2px;
  border-radius: 2px;
  -webkit-transition: all 0.4s;
  -moz-transition: all 0.4s;
  transition: all 0.4s;
}

a.dlbtn:hover, a.dlbtn:focus {
  color: #fff;
  padding-right: 90px;
  background-color: #5381bf;
  border-color: #5381bf;
}


a.dlbtn .details {
  position: absolute;
  line-height: 11px;
  top: 4px;
  right: -15px;
  opacity: 0;
  background: #49668c;
  color: #fff;
  text-align: center;
  padding: 3px 4px;
  -webkit-border-radius: 3px;
  -moz-border-radius: 3px;
  border-radius: 3px;
  -webkit-transition: right 0.4s linear, opacity 0.25s;
  -moz-transition: right 0.4s linear, opacity 0.25s;
  transition: right 0.4s linear, opacity 0.25s;
}
a.dlbtn .details .size {
  display: block;
  padding-top: 3px;
}

a.dlbtn:hover .details, a.dlbtn:focus .details {
  right: 8px;
  opacity: 1;
}


/** large download button **/
a.dlbtn.big {
  height: 115px;
  line-height: 115px;
  padding: 0 80px;
  font-size: 26px;
  -webkit-border-radius: 8px;
  -moz-border-radius: 8px;
  border-radius: 8px;
}
a.dlbtn.big:hover, a.dlbtn.big:focus {
  padding-right: 160px;
}

a.dlbtn.big .details {
  top: 10px;
  font-size: 18px;
  line-height: 20px;
  padding: 6px 15px;
}

a.dlbtn.big:hover .details, a.dlbtn.big:focus .details {
  right: 15px;
}


a.dlbtn .dlicon {
  display: block;
  font-size: 55px;
  line-height: 30px;
}


/** responsive styles **/
@media screen and (max-width: 620px) {
  h1 { font-size: 2.7em; }
  .center { width: 30%; }
  .centerbig { width: 70%; }
}

@media screen and (max-width: 480px) {
  h1 { font-size: 2.2em; }
  .center { margin-left: 0; }
  .centerbig { margin-left: -20px; }
  
  a.dlbtn.big { padding: 0 70px; }
  a.dlbtn.big:hover, a.dlbtn.big:focus { padding-right: 150px; }
}