Columns CSS. How do I align two columns correctly?

I'm trying to make two columns for my home page, but I can't seem to align my two columns side by side correctly: http://prntscr.com/7fun6n

I have applied border-bottom to my li tags, but as you can see in the image above, it is not aligned correctly.

My HTML code:

            <div id="index-features">
                <ul>
                    <li>
                        <h5 id="feature-1" class="feature-title">Instant access</h5>
                        <span id="feature-1-description" class="feature-description">After purchasing a style, there will be no waiting. Your account will be directly promoted in the "Customers" group and you will unlock access to all the features of the forum.</span>
                    </li>
                    <li>
                        <h5 id="feature-2" class="feature-title">Compatibility with all browsers</h5>
                        <span id="feature-2-description" class="feature-description">The styles are tested on all browsers to analyze any bugs and if we find, we correct them.</span>
                    </li>
                    <li>
                        <h5 id="feature-3" class="feature-title">Modern techniques</h5>
                        <span id="feature-3-description" class="feature-description">We use modern techniques (CSS3 gradients, etc.) to stand out from others.</span>
                    </li>
                    <li>
                        <h5 id="feature-4" class="feature-title">Compatibility with the default XenForo products</h5>
                        <span id="feature-4-description" class="feature-description">The styles are worked not only for the forum software, but also for the default XenForo products (Media Gallery and Resource Manager).</span>
                    </li>
                    <li>
                        <h5 id="feature-5" class="feature-title">Optional copyright removal</h5>
                        <span id="feature-5-description" class="feature-description">By paying more for a style, you can remove the copyright ("Style by XenDesignFocus") of the style.</span>
                    </li>
                </ul>
                <ul>
                    <li>
                        <h5 id="feature-6" class="feature-title">Compatibility with any resolution</h5>
                        <span id="feature-6-description" class="feature-description">The styles are designed to be compatible on any resolution. They are responsive, so they will fit on tablet and mobile.</span>
                    </li>
                    <li>
                        <h5 id="feature-7" class="feature-title">High quality support</h5>
                        <span id="feature-7-description" class="feature-description">If you need help about a purchased style here, ask in the <a href="#" target="_blank" style="border-bottom: 2px solid;">support forum</a> so that we can fix your problem very quickly.</span>
                    </li>
                    <li>
                        <h5 id="feature-8" class="feature-title">Custom framework</h5>
                        <span id="feature-8-description" class="feature-description">All styles are based on a custom framework for features such as the ability to change the logo image with a HTML logo text, make the appearance of the avatars in rounded, put a custom node icon for each forum, etc.</span>
                    </li>
                    <li>
                        <h5 id="feature-9" class="feature-title">Extra features</h5>
                        <span id="feature-9-description" class="feature-description">In addition to the custom framework, some styles have custom features such as for example the possibility to enable the fixed header option, etc.</span>
                    </li>
                    <li>
                        <h5 id="feature-10" class="feature-title">uuuuu</h5>
                        <span id="feature-10-description" class="feature-description">ffffcan remove the copyright ("Style by XenDesignFocus") of the style.</span>
                    </li>
                </ul>
            </div>

      

        
        
        
      

    

My CSS:

#index-features
{
    position: relative;
    margin-top: 15px;
    text-align: center;
}

#index-features ul
{
    float: left;
    width: 45%;
}

#index-features li
{
    border-bottom: #CCCCCC 1px solid;
    margin: 0 -20px 20px -20px;
    padding: 0 20px; 0 20px;
}

.feature-title
{
    display: inline-block;
    font-weight: bold;
}

.feature-title:before
{
    content: "";
    float: left;
    background: url("../images/index-features-sprite.png") no-repeat;
    width: 32px;
    height: 32px;
    margin-right: 5px;
}

.feature-description
{
    display: block;
    margin: 0 0 20px 37px;
}

#feature-1:before
{
    background-position: 0 0;
}

#feature-2:before
{
    background-position: -32px 0;
}

#feature-3:before
{
    background-position: -64px 0;
}

#feature-4:before
{
    background-position: 0 -32px;
}

#feature-5:before
{
    background-position: -32px -32px;
}

#feature-6:before
{
    background-position: 0 -64px;
}

#feature-7:before
{
    background-position: -32px -64px;
}

#feature-8:before
{
    background-position: -64px -32px;
}

#feature-9:before
{
    background-position: -64px -64px;
}

      

        
        
        
      

    

I would like to know what needs to be added to keep everything neatly side by side.