jQuery.css

Requirements

• Export $ as both a named and default export. Accept a valid CSS selector string and capture the first matching HTML element when $ is called.
• Return an object with css(property, value). Both arguments are strings; CSS values that need units include them, for example "20px".
• Support standard camelCase and kebab-case property names, plus CSS custom properties beginning with -- whose case must be preserved.
• Set the inline style of the selected element while preserving its content and unrelated styles. An empty value removes the inline property.
• Return the same wrapper object from every css call so multiple changes can be chained.
• If no element matches, css is a chainable no-op. Multiple wrappers keep their own independent selections.
• Only the first matching element is changed. Getters, multiple-element selection, numeric unit conversion, object setters, !important handling, SVG, and other jQuery features are out of scope. Do not import jQuery.

Examples

Input: $("#box").css("color", "red").css("backgroundColor", "black");
Output: The first #box element has red text and a black background.

Input: $("#box").css("width", "120px").css("--accent", "blue");
Output: Inline width is 120px and --accent is blue.

Input: $("#missing").css("color", "red");
Output: No error; returns the wrapper unchanged.