&lt;h2&gt;Important globals&lt;/h2&gt;

&lt;p&gt;Bootstrap employs a handful of important global styles and settings that you’ll need to be aware of when using it, all of which are almost exclusively geared towards the &lt;em&gt;normalization&lt;/em&gt; of cross browser styles. Let’s dive in.&lt;/p&gt;

&lt;h3&gt;HTML5 doctype&lt;/h3&gt;

&lt;p&gt;Bootstrap requires the use of the HTML5 doctype. Without it, you’ll see some funky incomplete styling, but including it shouldn’t cause any considerable hiccups.&lt;/p&gt;

&lt;div class=&quot;bd-clipboard&quot; style=&quot;box-sizing: border-box; position: relative; float: right; color: rgb(33, 37, 41); font-family: -apple-system, BlinkMacSystemFont, &amp;quot;Segoe UI&amp;quot;, Roboto, &amp;quot;Helvetica Neue&amp;quot;, Arial, &amp;quot;Noto Sans&amp;quot;, sans-serif, &amp;quot;Apple Color Emoji&amp;quot;, &amp;quot;Segoe UI Emoji&amp;quot;, &amp;quot;Segoe UI Symbol&amp;quot;, &amp;quot;Noto Color Emoji&amp;quot;; font-size: 16px;&quot;&gt;Copy&lt;/div&gt;

&lt;pre&gt;
&lt;code&gt;&lt;span style=&quot;color:rgb(0, 153, 153)&quot;&gt;&lt;!doctype html&gt;&lt;/span&gt;
&lt;span style=&quot;color:rgb(47, 111, 159)&quot;&gt;&lt;html&lt;/span&gt; &lt;span style=&quot;color:rgb(79, 159, 207)&quot;&gt;lang=&lt;/span&gt;&lt;span style=&quot;color:rgb(212, 73, 80)&quot;&gt;&quot;en&quot;&lt;/span&gt;&lt;span style=&quot;color:rgb(47, 111, 159)&quot;&gt;&gt;&lt;/span&gt;
  ...
&lt;span style=&quot;color:rgb(47, 111, 159)&quot;&gt;&lt;/html&gt;&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;

&lt;h3&gt;Responsive meta tag&lt;/h3&gt;

&lt;p&gt;Bootstrap is developed &lt;em&gt;mobile first&lt;/em&gt;, a strategy in which we optimize code for mobile devices first and then scale up components as necessary using CSS media queries. To ensure proper rendering and touch zooming for all devices, add the responsive viewport meta tag to your &lt;/p&gt;