Sidebar DIV appearing after blog post - php

Question

I've looked this up and have found numerous similar issues - tried troubleshooting but couldn't work it out, I can't for the life of me figure out why the div is dropping below the blog post, pushing everything out. The sidebar should sit next to the blog post, i.e. 3/4 post, 1/4 sidebar. Instead the sidebar is pushed below the post. This happens to all posts regardless of images/text etc.... so it's not an image or text issue from what I gather.
http://pastestudios.com/buying-property-sydney/
<div id="pageHead">
<?php $blog_page_id = of_get_option('ttrust_blog_page'); ?>
<?php $blog_page = get_page($blog_page_id); ?>
<h1><?php echo $blog_page->post_title; ?></h1>
<?php $page_description = get_post_meta($blog_page_id, "_ttrust_page_description_value", true); ?>
<?php if ($page_description) : ?>
<p><?php echo $page_description; ?></p>
<?php endif; ?>
</div>
<div id="content" class="threeFourth clearfix">
<?php while (have_posts()) : the_post(); ?>
<div <?php post_class(); ?>>
<h1><a href="<?php the_permalink() ?>" rel="bookmark" ><?php the_title(); ?></a></h1>
<div class="meta clearfix">
<?php $post_show_author = of_get_option('ttrust_post_show_author'); ?>
<?php $post_show_date = of_get_option('ttrust_post_show_date'); ?>
<?php $post_show_category = of_get_option('ttrust_post_show_category'); ?>
<?php $post_show_comments = of_get_option('ttrust_post_show_comments'); ?>
<?php if($post_show_author || $post_show_date || $post_show_category){ _e('Posted ', 'themetrust'); } ?>
<?php if($post_show_author) { _e('by ', 'themetrust'); the_author_posts_link(); }?>
<?php if($post_show_date) { _e('on', 'themetrust'); ?> <?php the_time( 'M j, Y' ); } ?>
<?php if($post_show_category) { _e('in', 'themetrust'); ?> <?php the_category(', '); } ?>
<?php if(($post_show_author || $post_show_date || $post_show_category) && $post_show_comments){ echo " | "; } ?>
<?php if($post_show_comments) : ?>
<?php comments_number(__('No Comments', 'themetrust'), __('One Comment', 'themetrust'), __('% Comments', 'themetrust')); ?>
<?php endif; ?>
</div>
<?php if(of_get_option('ttrust_post_show_featured_image')) : ?>
<?php if(has_post_thumbnail()) : ?>
<?php if(of_get_option('ttrust_post_featured_img_size')=="large") : ?>
<?php the_post_thumbnail('ttrust_post_thumb_big', array('class' => 'postThumb', 'alt' => ''.get_the_title().'', 'title' => ''.get_the_title().'')); ?>
<?php else: ?>
<?php the_post_thumbnail('ttrust_post_thumb_small', array('class' => 'postThumb alignleft', 'alt' => ''.get_the_title().'', 'title' => ''.get_the_title().'')); ?>
<?php endif; ?>
<?php endif; ?>
<?php endif; ?>
<?php the_content(); ?>
<?php wp_link_pages( array( 'before' => '<div class="pagination clearfix">Pages: ', 'after' => '</div>' ) ); ?>
</div>
<?php comments_template('', true); ?>
<?php endwhile; ?>
</div>
<?php get_sidebar(); ?>

Answer 1

First, set box-sizing: border-box
Next, make #content and #sidebar equal to 100% width. Right now you have #content set at 100% and #sidebar set in pixels so, naturally, it will push your sidebar down.
Try something like:
* { box-sizing: border-box; }
#content {
width: 65%;
}
#sidebar {
width: 35%;
}

Answer 2

Your article area is 100% wide. So there is no space for sidebar. Try to adjust width and margins to make total 100. Something like following code.
#content {
width: 70%;
float: left;
margin-left: 3%;
}
#sidebar {
width: 22%;
float: right;
margin-right: 3%;
}
Your image at Blog page does not adjust with browser width. See it in smaller screen size. To make it adjustable and remove horizontal scrollbar at smaller resolutions, use following CSS code.
#content .alignleft,
#content img.alignleft {
max-width: 100%;
}

Answer 3

It looked like you may have been working on it while I had a look at it. At the time I was able to change width: 100%; to width: 720px; in your #content id and it seemed to work in getting the sidebar vertically aligned to top, side by side with your content area.
I also noticed you had multiple ids of the same name, #content in particular. Might want to clean up the css so you can look at it more clearly if you have any more problems. Happens to me all the time when I'm chasing a problem, my css gets out of control and I lose track of the changes I made to try and correct the problems.