In Polymer 0.5, layout values were attributes.
<div horizontal layout> <div flex></div> <div></div> </div>
In Polymer 1.0, they are classes.
so the 1st import of the item. then use it as shown below.
<div class="horizontal layout"> <div class="flex"></div> <div></div> </div>
this code will give you a div spanning the width of the page with a flexible div spanning the entire width, except for the width of the contents of the second div.
hope this indicates that you are in the right direction.
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