Create a bold, eye-catching book cover illustration for a Word Search book titled Sopa de Letras con Vocales Faltantes, and subtitled, 100 Missing‑Vowel Word Search Puzzles. Designed for adult readers. The cover should look clean and modern but still intriguing to a casual observer. The style is colorful, friendly, and clear, with clean lines and vibrant tones that appeal to the target audience. The layout should feel fun and engaging while keeping the title space uncluttered. Leave clear space at the top for the title and at the bottom for the subtitle. The overall look should stand out on Amazon thumbnails, making it instantly clear this is a word search puzzle book.