Trying to target specific input field?

Hi guys, I've tried using the CSS samples in the help section, but I think I keep putting it in wrong.

I have a forum where I'm trying to target one specific input field out of the rest of the customized fields on the form.

The code for the form itself looks like this:

body.custom .gform_wrapper .gform_body .gform_fields .gfield input[type=text],
body.custom .gform_wrapper .gform_body .gform_fields .gfield input[type=email],
body.custom .gform_wrapper .gform_body .gform_fields .gfield input[type=tel] {
-webkit-border-radius: 8px;
-moz-border-radius: 8px;
border-radius: 8px;
background-color: white;
color: #333;
border: 1px solid #CCC;
font-size: 17px!important;
box-shadow: inset 0px 0px 5px #e5e5e5;
-moz-box-shadow: inset 0px 0px 5px #e5e5e5;
-webkit-box-shadow: inset 0px 0px 5px #e5e5e5;
word-spacing: 0.4pt;
letter-spacing: 0.2pt;
color: #000000;
height: 40px;
width: 100px;
font-size: 17px!important;
line-height: 25px;
padding: 0 10px;
}

The CSS for the input field I'm trying to target (and in this case make the background red is below):

<div class="ginput_container">
<input name="input_16" id="input_1_16" type="text" value="" class="medium" tabindex="10"/>
</div>

Could someone share an example css of targeting this specific id in css within the string:
body.custom .gform_wrapper .gform_body .gform_fields .gfield input[type=text]

You rock Richard, thank you so much! I saw the help documentation but it felt like I was reading latin for some reason (I'm not a great computer coder guy)