html - Why can't I use CSS to move button? -

this code , i'm unable style using 'button {margin-top:10px}

<input type="text"></input><button type="button"><img src="searchlogo.png" id="search"></button> 

it isn't aligning flush text input? tips?

to see how margin working please see demo

css

    .b1{     background:orange;     color:white;     border:none;  }  .b2{     background:orange;     color:white;     border:none;    margin-top:100px; } 

html

<input type="text"></input><button class="b1">button title</button> <br/> <input type="text"></input><button class="b2">button title</button> <br/> <input type="text"></input><button class="b1">button title</button>