Best way to pass styling to a component

I would just use a styles input property on InputEdit, and pass in an object with the desired styles:

<InputEdit [styles]="stylesObj">                 // in host component's template

stylesObj = {font-size: '1.1em', color: 'red'};  // in host component class

<input [ngStyle]="stylesObj" ...>                // in InputEdit component's template

If you have multiple DOM elements you want to style, pass in a more complex object:

<InputEdit [styles]="stylesObj">

stylesObj = {
  input: {font-size: '1.1em', color: 'red'}
  label: { ... } 
};

<label [ngStyle]="styles.label" ...>
<input [ngStyle]="styles.input" ...>