Dropdown with a form inside with twitter-bootstrap

I have a Dropdown in my TopBar, built with the Twitter Bootstrap CSS framework.

I have 3 problems with it that I can't find any solution to:

1. The text and password input fields are far too big, how can I adjust them? Making the dropdown box bigger would be OK too.
2. The labels for the fields are too dark, how can I lighten them up a bit?
3. The Dropdown is closing when I click into one of the fields. I have to reopen it and then I can type until clicking in the next field. The values are preserved even when the dropdown is closed. How can I make it stay open?

Here is a screenshot of problems 1 and 2:

Also here is the HTML for the TopBar as it is now.

<div class='topbar-wrapper'>
  <div class='topbar'>
    <div class='topbar-inner'>
      <div class='container'>
        <h3>
          <a href="/">Webworld</a>
        </h3>
        <ul class='nav'>
          <li>FILLER...</li>
        </ul>
        <ul class='nav secondary-nav'>
          <li class='dropdown' data-dropdown='dropdown'>
            <a href="#" class="dropdown-toggle">Login</a>
            <div class='dropdown-menu' id='signin-dropdown'>
              <form accept-charset="UTF-8" action="/sessions" method="post"><div style="margin:0;padding:0;display:inline"><input name="utf8" type="hidden" value="&#x2713;" /><input name="authenticity_token" type="hidden" value="4L/A2ZMYkhTD3IiNDMTuB/fhPRvyCNGEsaZocUUpw40=" /></div>
                <fieldset class='textbox'>
                  <label id='js-username'>
                    <span>Username</span>
                    <input autocomplete="on" id="username" name="username" type="text" />
                  </label>
                  <label id='password'>
                    <span>Passwort</span>
                    <input id="userpassword" name="userpassword" type="password" />
                  </label>
                </fieldset>
                <fieldset class='subchk'>
                  <input name="commit" type="submit" value="Log In" />
                </fieldset>
              </form>
            </div>
          </li>
        </ul>
      </div>
    </div>
  </div>
</div>

There hidden input is needed by rails and autogenerated.

I've already tried to copy the implementation of the login form that twitter uses, but when I tried that, the TopBar is about 250px in height and the content of the dropdown is open, not closeable.

I have no custom CSS or JavaScript so far, except for the top-padding of 40px in the body as suggested by the bootstrap docs.

Can someone help me with this?

Try adding the code below somewhere in your javascript. It should stop it from happening.

  $('.dropdown-menu').find('form').click(function (e) {
    e.stopPropagation();
  });

(Twitter Bootstrap 2.x)

You may want to move the contents of style="" to your stylesheets...

If user entered wrong password:

add class open to li class="dropdown open"

and class error to fieldset class="control-group error"

<ul class="nav pull-right">
  <li class="dropdown">
    <a href="#" class="dropdown-toggle" data-toggle="dropdown">Login <b class="caret"></b></a>
    <div class="dropdown-menu">
      <form action="" id="form_login" style="margin: 0; padding: 3px 15px" accept-charset="utf-8" method="post">
        <fieldset class="control-group">
          <label for="form_email" class="control-label">Email address</label>
          <div class="controls">
            <div class="input-prepend" style="white-space: nowrap">
              <span class="add-on"><i class="icon-envelope"></i></span>
              <input type="email" name="email" id="form_email" autocomplete="on" class="span2">
            </div>
          </div>
        </fieldset>
        <fieldset class="control-group">
          <label for="form_password" class="control-label">Password</label>
          <div class="controls">
            <div class="input-prepend" style="white-space: nowrap">
              <span class="add-on"><i class="icon-lock"></i></span>
              <input type="password" name="password" id="form_password" class="span2">
            </div>
          </div>
        </fieldset>
        <label class="checkbox">
          <input type="checkbox" name="remember" value="true"> Remember me
        </label>
        <p class="navbar-text">
          <button type="submit" class="btn btn-primary">Login</button>
        </p>
      </form>
    </div>
  </li>
</ul>

You don't need any extra css or javascript to make this look nice (with TB2.x)