SOURCE

<div id="wrapper">
  <div class="container">
    <div class="demo">
      <h1>
        宽度50％, 字体10％
      </h1>
    </div>
    <div class="demo2">
      <h2>
        宽度80％, 字体8％
      </h2>
    </div>
    <div class="demo3">
      <h3>
        宽度50％, 字体5％
      </h3>
    </div>
    <div class="demo4">
      <h3>
        宽度10％, 高度50％, 字体1％
      </h3>
    </div>
  </div>
</div>

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 {
    background: #FFF;
    font-family: "Trebuchet MS", Arial, Helvetica, sans-serif;
    color: #313131;
    font-size: 62.5%;
    line-height: 1;
}

::selection {
    background: #50688B;
    color: #FFF;
}

::-moz-selection {
    background: #50688B;
    color: #FFF;
}

::-webkit-selection {
    background: #50688B;
    color: #FFF;
}

::-webkit-input-placeholder { /* WebKit browsers */
    color: #ccc;
    font-style: italic;
}

:-moz-placeholder { /* Mozilla Firefox 4 to 18 */
    color: #ccc;
    font-style: italic;
}

::-moz-placeholder { /* Mozilla Firefox 19+ */
    color: #ccc;
    font-style: italic;
}

:-ms-input-placeholder { /* Internet Explorer 10+ */
    color: #ccc !important;
    font-style: italic;
}

br {
    display: block;
    line-height: 2.2em;
}

hr {
    width: 75%;
    border: 1px solid #ccc;
    margin-bottom: 15px;
}

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;
    }

sup {
    vertical-align: super;
    font-size: 0.7em;
}

b, strong {
    font-weight: bold;
}

i, em {
    font-style: italic;
}

table {
    border-collapse: collapse;
    border-spacing: 0;
}

img {
    border: 0;
    max-width: 100%;
}

/* DEMO HEADER */
#topbar {
    width: 100%;
    background: #404853;
    padding: 10px 0 10px 0;
    text-align: center;
    height: 36px;
    overflow: hidden;
    position: fixed;
    z-index: 1111;
}

    #topbar a {
        color: rgba(255, 255, 255, 0.9);
        font-size: 1.3em;
        line-height: 1.25em;
        text-decoration: none;
        opacity: 0.5;
        font-weight: bold;
    }

        #topbar a:hover {
            opacity: 1;
        }
/* DEMO BODY */
#wrapper {
    margin: 0 auto;
    position: relative;
}
header {
    padding: 10px 0 0;
    background-color: #404853;
}
.container {
    overflow: hidden;
    position: relative;
    padding-top: 36px;
}
/* Footer Bar */
footer {
    background: #404853;
    bottom: 0;
    clear: both;
    overflow: hidden;
    padding: 10px;
    position: fixed;
    text-align: center;
    width: 100%;
}
footer p {
    color: #BBB;
    letter-spacing: 1px;
    font-size: 12px;
    text-shadow: 0 1px 0 rgba(0, 0, 0, 0.3);
}
    footer strong {
        color: #FFF;
    }
footer p a {
    letter-spacing: 0;
}

/** typography **/
h1, h2, h3, h4{
    font-family: "Microsoft YaHei",Arial,sans-serif;
    line-height: 2em;
    letter-spacing: -0.05em;
    margin-bottom: 20px;
    position: relative;
    overflow: hidden;
    text-align: center;
}

a {
    color: #FFF;
    text-decoration: none;
}

    a:hover {
        text-decoration: underline;
    }

.center {
    display: block;
    text-align: center;
}

/** clearfix **/
.clearfix:after {
    content: ".";
    display: block;
    clear: both;
    visibility: hidden;
    line-height: 0;
    height: 0;
}

.clearfix {
    display: inline-block;
}

html[xmlns] .clearfix {
    display: block;
}

* html .clearfix {
    height: 1%;
}

/* Demo */
.demo {
   width: 100vw;
   font-size: 10vw;
   margin: 0 auto;
   background-color: #50688B;
   color: #FFF;
}
.demo2 {
   width: 80vw;
   font-size: 8vw;
   margin: 0 auto;
}
.demo3 {
   width: 50vw;
   font-size: 5vw;
   margin: 0 auto;
   background-color: #ff6a00;
   color: #FFF;
}
.demo4 {
   width: 10vw;
   height: 50vh;
   font-size: 1vw;
   margin: 0 auto;
   background-color: #ff006e;
   color: #FFF;
}