Yeah, you may have to customize to display the logo in the same line with main menu like the t3-framework.org site. You can load the mainmenu to the header.php file, in that case you don't need the mainnav.php block anymore, so you can rename or unload the mainnav in the layout file.
Example:
I use the code in the header.php file then rename the mainnav.php file.
<?php
/**
* @package T3 Blank
* @copyright Copyright (C) 2005 - 2012 Open Source Matters, Inc. All rights reserved.
* @license GNU General Public License version 2 or later; see LICENSE.txt
*/
defined('_JEXEC') or die;
// get params
$sitename = $this->params->get('sitename');
$slogan = $this->params->get('slogan', '');
$logotype = $this->params->get('logotype', 'text');
$logoimage = $logotype == 'image' ? $this->params->get('logoimage', 'templates/' . T3_TEMPLATE . '/images/logo.png') : '';
$logoimgsm = ($logotype == 'image' && $this->params->get('enable_logoimage_sm', 0)) ? $this->params->get('logoimage_sm', '') : false;
if (!$sitename) {
$sitename = JFactory::getConfig()->get('sitename');
}
?>
<!-- MAIN NAVIGATION -->
<header id="t3-mainnav" class="wrap navbar navbar-default navbar-fixed-top t3-mainnav">
<div class="container">
<!-- NAVBAR HEADER -->
<div class="navbar-header">
<!-- LOGO -->
<div class="logo logo-<?php echo $logotype ?>">
<div class="logo-<?php echo $logotype, ($logoimgsm ? ' logo-control' : '') ?>">
<a href="/<?php echo JURI::base(true) ?>" title="<?php echo strip_tags($sitename) ?>">
<?php if($logotype == 'image'): ?>
<img class="logo-img" src="/<?php echo JURI::base(true) . '/' . $logoimage ?>" alt="<?php echo strip_tags($sitename) ?>" />
<?php endif ?>
<?php if($logoimgsm) : ?>
<img class="logo-img-sm" src="/<?php echo JURI::base(true) . '/' . $logoimgsm ?>" alt="<?php echo strip_tags($sitename) ?>" />
<?php endif ?>
<span><?php echo $sitename ?></span>
</a>
</div>
</div>
<!-- //LOGO -->
<?php if ($this->getParam('navigation_collapse_enable', 1) && $this->getParam('responsive', 1)) : ?>
<?php $this->addScript(T3_URL.'/js/nav-collapse.js'); ?>
<button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".t3-navbar-collapse">
<i class="fa fa-bars"></i>
</button>
<?php endif ?>
<?php if ($this->countModules('head-search')) : ?>
<!-- HEAD SEARCH -->
<div class="head-search<?php $this->_c('head-search')?>">
<jdoc:include type="modules" name="<?php $this->_p('head-search') ?>" style="raw" />
</div>
<!-- //HEAD SEARCH -->
<?php endif ?>
</div>
<!-- //NAVBAR HEADER -->
<!-- NAVBAR MAIN -->
<?php if ($this->getParam('navigation_collapse_enable')) : ?>
<nav class="t3-navbar-collapse navbar-collapse collapse"></nav>
<?php endif ?>
<nav class="t3-navbar navbar-collapse collapse">
<jdoc:include type="<?php echo $this->getParam('navigation_type', 'megamenu') ?>" name="<?php echo $this->getParam('mm_type', 'mainmenu') ?>" />
</nav>
<!-- //NAVBAR MAIN -->
</div>
</header>
<!-- //MAIN NAVIGATION -->
Any option will requires you to customize the style.
Gardner.