Bootstrap でスマートフォンサイトの幅が少しだけ広くなってしまう現象 ref: http://qiita.com/satosystems/items/9a9ef06b1f72e2d1b3b9

file0.html

<div class="container">
  <div class="row">
    <form action="#" class="form-horizontal">
      <div class="form-group container"><!-- ここが問題 -->
        <label for="input-name" class="col-sm-2 control-label">おなまえ</label>
        <div class="col-xs-12 col-sm-8">
          <input type="text" class="form-control" id="input-name" placeholder="おなまえ" maxlength="80" required="required">
        </div>
      </div>

file1.html

<div class="container">
  <div class="row">
    <form action="#" class="form-horizontal">
      <div class="container"><!-- container と -->
        <div class="form-group"><!-- form-group を分ける -->
          <label for="input-name" class="col-sm-2 control-label">おなまえ</label>
          <div class="col-xs-12 col-sm-8">
            <input type="text" class="form-control" id="input-name" placeholder="おなまえ" maxlength="80" required="required">
          </div>
        </div>
      </div>