Add CSS to Php Wordpress plugin

Question

I wrote a simple plugin which sets some css code using wp_options. It all looks similar like this:

add_action('init','easy_style');

function easy_style()
{
    ?>
    <style>
    #header a {
        color: <?php echo get_option('topcolor'); ?>;
        font-size: <?php echo get_option('topsize'); ?>px;
        <?php
            if (get_option('topstyle') == "bold")
            { echo "font-weight: bold;"; echo "font-style: normal;"; }
            elseif (get_option('topstyle') == "italic")
            { echo "font-style: italic;"; echo "font-weight: normal;"; }
            elseif (get_option('topstyle') == "bolditalic")
            { echo "font-weight: bold;"; echo "font-style: italic;"; }
            else { echo "font-weight: normal;"; echo "font-style: normal;"; }
        ?>;
    }

    </style>
    <?php
}

Now this works, but if I activate my "Contact Form 7" plugin, the contact form 7 doesn't work anymore. It can't send any mails. So I think what I do is wrong. If I remove this piece of code, the contact form works again...

I think I do it wrong because the css needs to be loaded in the header, no? So what I thought I would do as a test is put the same code in the header. However then some other css (i don't know where) overwrites these, so this also doesn't work.

I think there are some wp functions to add css code to the header but I don't know how exacly.

Any ideas?

Thanks

Answer 1

A safe way to add CSS to your plugin is to use wp_enqueue_style.

/**
 * Register with hook 'wp_enqueue_scripts', which can be used for front end CSS and JavaScript
 */
add_action( 'wp_enqueue_scripts', 'prefix_add_my_stylesheet' );

/**
 * Enqueue plugin style-file
 */
function prefix_add_my_stylesheet() {
    // Respects SSL, Style.css is relative to the current file
    wp_register_style( 'prefix-style', plugins_url('style.css', __FILE__) );
    wp_enqueue_style( 'prefix-style' );
}

Reference.