Create a vertical, high-resolution digital cartoon illustration of a large, glossy red heart floating in a bright blue sky. The heart has a bold black outline, a warm orange-yellow highlight on the upper left, and deep purple shading along the lower-right edge to give it a shiny, three-dimensional look. Surround the heart with fluffy, rounded white clouds with subtle light blue outlines. A gentle gradient in the sky transitions from lighter blue at the top to a slightly deeper blue toward the bottom. The scene is playful, cute, and romantic, with a clean, vector-like cartoon style suitable for a children-friendly poster.