Additional CSS to make MDL (elm-mdl) hide address-bar in mobile on scroll. May have adverse side-effects.

AdditionalCSS.elm

import Material.Style as Style
import Html exposing (Html)

-- Put this somewhere in your main contents. 

additionalCSS : Html
additionalCSS = 
  Style.stylesheet """
    html, body {
      overflow-y: auto;
      min-height: 100%;
    }
    mdl-layout {
      min-height: 100%;
    }
    .mdl-layout {
        overflow: visible;
    }
    .mdl-layout__drawer {
        position: fixed;
    }
    .mdl-layout__content {
        display: block;
        overflow: visible;
        margin-top: 64px;
    }
    .is-small-screen .mdl-layout__content {
        margin-top: 56px;
    }
    .mdl-layout__header {
        position: fixed;
    }
    .mdl-layout__obfuscator {
        position: fixed;
    }
  """