:root{--primary: #FF6B6B;--secondary: #4ECDC4;--accent: #FFE66D;--background: #F7FFF7;--text-main: #2C3E50;--card-bg: #FFFFFF;--shadow: 0 10px 20px rgba(0,0,0,.08);--hover-shadow: 0 15px 30px rgba(0,0,0,.15);--font-heading: "Fredoka One", cursive;--font-body: "Nunito", sans-serif}*{box-sizing:border-box;margin:0;padding:0}body{font-family:var(--font-body);background-color:var(--background);color:var(--text-main);line-height:1.6;min-height:100vh;overflow-x:hidden;position:relative}.background-decor{position:fixed;top:0;left:0;width:100%;height:100%;background-image:radial-gradient(var(--accent) 15%,transparent 16%),radial-gradient(var(--secondary) 15%,transparent 16%);background-size:60px 60px;background-position:0 0,30px 30px;opacity:.1;z-index:-1}.background-decor-book{position:fixed;top:0;left:0;width:100%;height:100%;background:linear-gradient(135deg,#a8edea,#fed6e3);z-index:-1}.container{max-width:1200px;margin:0 auto;padding:0 20px}.header{text-align:center;padding:3rem 0;margin-bottom:2rem}.logo{font-family:var(--font-heading);font-size:3.5rem;color:var(--primary);text-shadow:2px 2px 0px white,4px 4px 0px var(--secondary);margin-bottom:.5rem;letter-spacing:2px}.subtitle{font-size:1.5rem;font-weight:700;color:var(--secondary)}.library{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:30px;padding-bottom:5rem}.book-card{background:var(--card-bg);border-radius:20px;padding:15px;text-align:center;text-decoration:none;color:inherit;box-shadow:var(--shadow);transition:transform .3s cubic-bezier(.175,.885,.32,1.275),box-shadow .3s ease;border:4px solid transparent;cursor:pointer;display:flex;flex-direction:column}.book-card:hover{transform:translateY(-10px) scale(1.02);box-shadow:var(--hover-shadow);border-color:var(--accent)}.book-cover{width:100%;height:300px;object-fit:cover;border-radius:12px;margin-bottom:15px;box-shadow:0 4px 8px #0000001a}.book-info h3{font-family:var(--font-heading);font-size:1.5rem;margin-bottom:5px}.level-badge{display:inline-block;background:var(--primary);color:#fff;padding:5px 15px;border-radius:20px;font-weight:800;font-size:.9rem;text-transform:uppercase;letter-spacing:1px}.loading{grid-column:1 / -1;text-align:center;font-size:1.5rem;font-weight:700;color:var(--primary);display:flex;flex-direction:column;align-items:center;gap:15px}.spinner{width:50px;height:50px;border:5px solid var(--accent);border-top:5px solid var(--primary);border-radius:50%;animation:spin 1s linear infinite}@keyframes spin{0%{transform:rotate(0)}to{transform:rotate(360deg)}}.btn{display:inline-block;background:var(--primary);color:#fff;border:none;padding:12px 24px;font-family:var(--font-heading);font-size:1.1rem;border-radius:30px;cursor:pointer;text-decoration:none;transition:all .2s ease;box-shadow:0 4px 0 darken(var(--primary),10%)}.btn:active{transform:translateY(4px);box-shadow:none}.btn-back{background:#fff;color:var(--text-main);box-shadow:0 4px #e0e0e0}.btn-audio{background:var(--secondary);box-shadow:0 4px #3eb3ab}.btn-control{background:var(--accent);color:var(--text-main);box-shadow:0 4px #d4b830;font-size:1.2rem;padding:10px 30px}.book-nav{display:flex;justify-content:space-between;align-items:center;padding:20px 40px;background:#ffffffb3;-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);box-shadow:0 2px 10px #0000000d;position:sticky;top:0;z-index:100}.book-title-display{font-family:var(--font-heading);font-size:2rem;color:var(--primary)}.flipbook-container{padding:40px 20px 20px;display:flex;flex-direction:column;align-items:center;width:100%}.flipbook-wrapper{position:relative;width:100%;max-width:800px;height:480px;display:flex;justify-content:center;align-items:center;margin:0 auto}.flip-book{box-shadow:0 0 20px #0003;display:none;margin:0 auto}.page{background-color:#fdfbf7;border:solid 1px #c2b5a3;overflow:hidden;box-shadow:inset -2px 0 5px #0000000d}.page.-left{border-right:0;box-shadow:inset -10px 0 20px #0000001a}.page.-right{border-left:0;box-shadow:inset 10px 0 20px #0000001a}.page-content{width:100%;height:100%;display:flex;flex-direction:column;padding:30px;background:#fff}.page-image{width:100%;height:60%;object-fit:cover;border-radius:8px;margin-bottom:20px;border:3px solid #eee}.page-text{font-size:2.5rem;font-weight:800;text-align:center;color:var(--text-main);flex-grow:1;display:flex;align-items:center;justify-content:center;line-height:1.4}.page.hardcover{background-color:var(--primary);border:solid 1px darken(var(--primary),10%)}.page.hardcover .page-content{background-color:var(--primary);color:#fff;justify-content:center;align-items:center}.page.hardcover .book-cover{width:80%;height:auto;max-height:70%;object-fit:contain;border-radius:5px;box-shadow:0 10px 20px #0000004d}.page.hardcover h2{font-family:var(--font-heading);font-size:3rem;text-shadow:2px 2px 4px rgba(0,0,0,.2);text-align:center;margin-top:20px}.page-number{position:absolute;bottom:10px;font-size:1rem;color:#999;font-weight:700}.page.-left .page-number{left:15px}.page.-right .page-number{right:15px}.book-controls{margin-top:30px;display:flex;align-items:center;gap:20px;background:#fff;padding:15px 30px;border-radius:40px;box-shadow:var(--shadow)}.page-counter{font-size:1.2rem;font-weight:700;color:var(--text-main);min-width:120px;text-align:center}.error-container{text-align:center;padding:100px 20px}@media (max-width: 768px){.flipbook-wrapper{height:400px}.book-nav{flex-direction:column;gap:10px;padding:10px}.book-title-display{font-size:1.5rem}.btn{padding:8px 16px;font-size:1rem}.flipbook-container{padding:10px}.page-content{padding:15px}.page-image{margin-bottom:10px;height:50%}.page-text{font-size:1.3rem}.page.hardcover h2{font-size:1.8rem}.book-controls{flex-wrap:wrap;justify-content:center;padding:10px;gap:10px;margin-top:20px}.btn-control{padding:8px 20px;font-size:1rem}}