In order to create some CSS for your custom components you have to use your predefined inputs. Take a look at the example below.
VSComponents.add({ title: "Text", form: { inputList: [ { type: "textarea", tooltip: "Enter your text", label: "Text", dataName: "text", // This input will be rendered in your template. important: true }, { type: "text", tooltip: "Pick a color for the text", label: "Text color", dataName: "textColor", // And this one in your css code. dataType: "color" } ] }, template: [ "<section>", "<div class='text'><%= text %></div>", "</section>", ].join(""), css: [ // Array - list of selectors. { selector: ".text", // String - make a selection on your component and don't worry about scoping the component, VS Builder will scope it for you with the parent's unique class. properties : [ // Array - the list of css properties on the same selector. { name : "color", // String - a css property name such as: background-color, font-size, line-height, etc. value : "textColor" // String - as value use the dataName of your input. Just make sure that your input will return the value that your css property name will expect. } ] } ] });