*{box-sizing:border-box}body{margin:0;font-family:Segoe UI,system-ui,-apple-system,sans-serif;background:linear-gradient(135deg,#667eea,#764ba2);min-height:100vh}.demo-container{max-width:700px;margin:0 auto;padding:40px 20px;text-align:center;color:#fff}.demo-container h1{font-size:2.5rem;margin-bottom:8px;text-shadow:0 2px 10px rgba(0,0,0,.2)}.subtitle{font-size:1.1rem;opacity:.9;margin-bottom:40px}.button-group{display:flex;flex-wrap:wrap;gap:12px;justify-content:center;margin-bottom:20px}.btn{padding:14px 28px;border:none;border-radius:8px;font-size:16px;font-weight:600;cursor:pointer;transition:all .2s ease;box-shadow:0 4px 12px #00000026}.btn:hover{transform:translateY(-2px);box-shadow:0 6px 16px #0003}.btn:active{transform:translateY(0)}.btn-success{background:linear-gradient(135deg,#10b981,#059669);color:#fff}.btn-error{background:linear-gradient(135deg,#ef4444,#dc2626);color:#fff}.btn-warning{background:linear-gradient(135deg,#f59e0b,#d97706);color:#fff}.btn-info{background:linear-gradient(135deg,#3b82f6,#2563eb);color:#fff}.btn-custom{background:linear-gradient(135deg,#8b5cf6,#7c3aed);color:#fff}.btn-clear{background:#fff3;color:#fff;border:2px solid rgba(255,255,255,.5)}.btn-clear:hover{background:#ffffff4d}.btn-theme{background:#ffffff26;color:#fff;border:2px solid rgba(255,255,255,.3);padding:10px 18px;font-size:14px}.btn-theme:hover{background:#ffffff40;border-color:#ffffff80}.btn-theme.active{background:#ffffff4d;border-color:#fff;box-shadow:0 0 0 2px #ffffff4d}.btn-all-themes{background:linear-gradient(135deg,#ec4899,#f43f5e);color:#fff}.section{margin-bottom:30px}.section h2{font-size:1.2rem;margin-bottom:15px;opacity:.95}.theme-group{background:#0000001a;padding:15px;border-radius:12px}.theme-hint{margin-top:10px;font-size:.9rem;opacity:.8}.theme-hint strong{text-transform:capitalize}.features{margin-top:50px;background:#ffffff1a;-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);border-radius:16px;padding:30px;text-align:left}.features h2{margin-top:0;margin-bottom:20px;font-size:1.5rem}.features ul{list-style:none;padding:0;margin:0}.features li{padding:8px 0;font-size:1rem;opacity:.95}.result-box{background:#ffffff26;-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);border-radius:12px;padding:20px;margin-top:30px;text-align:center}.result-box h3{margin:0 0 10px;font-size:1rem;opacity:.8}.result-box p{margin:0;font-size:1.25rem;font-weight:600}@media(max-width:480px){.demo-container h1{font-size:1.8rem}.btn{width:100%}}