Edit in JSFiddle

<h1>大标题</h1>
<p>文字1</p>
<p>文字2</p>
<p>文字3</p>
<h1>大标题</h1>
<p>文字1</p>
<p>文字2</p>
<p>文字3</p>
<h1>大标题</h1>
<p>文字1</p>
<p>文字2</p>
<p>文字3</p>

h1::before{
    content:counter(h)'.';
}
h1{
    counter-increment:h;
    counter-reset:p;
}
p::before{
    content:counter(p)'.';
    margin-left:40px;
}
p{
    counter-increment:p;
}