<h1>大标题</h1> <h2>中标题</h2> <h3>小标题</h3> <h3>小标题</h3> <h2>中标题</h2> <h3>小标题</h3> <h3>小标题</h3> <h1>大标题</h1> <h2>中标题</h2> <h3>小标题</h3> <h3>小标题</h3> <h2>中标题</h2> <h3>小标题</h3> <h3>小标题</h3>
h1::before{ content:counter(h1)'.'; } h1{ counter-increment:h1; counter-reset:h2; } h2::before{ content:counter(h1) '-' counter(h2); } h2{ counter-increment:h2; counter-reset:h3; margin-left:40px; } h3::before{ content:counter(h1) '-' counter(h2) '-' counter(h3); } h3{ counter-increment:h3; margin-left:80px; }