[role=search] {
    width: 100%;
    margin: 15px 0;
}

[role=search] input[type=text] {
    width: 96%;
    height: inherit;
    border-radius: 10px 0 0 10px;
}

[role=search] button[type=submit] {
    min-width: 0;
    margin: 0;
    padding: 6px 10px;
    border-radius: 0 10px 10px 0;
}