/* wwwroot/css/theme.css (or a new theme.css file) */ :root { /* Define the default background color */ /* Defines a variable and tells the body tag to use that variable for its background color.*/ --primary-bg-color: #ffffff; /* Default White */ /* Optionally, define a secondary color for text or accents */ --primary-text-color: #212529; /* Default Dark Gray */ /* Bootstrap utility colors rely on CSS variables too, but for custom elements, use your own variables. */ } /* Apply the custom property to the element */ body { background-color: var(--primary-bg-color); color: var(--primary-text-color); transition: background-color 0.3s ease; /* Smooth transition */ } /* Example: Apply a subtle change to the Navbar */ .navbar { border-bottom-color: var(--primary-bg-color) !important; }