*{margin:0;padding:0;box-sizing:border-box}body{font-family:Helvetica Neue,Arial,sans-serif;line-height:1.6;color:#333;background:linear-gradient(135deg,#667eea,#764ba2);min-height:100vh}#app{min-height:100vh}.container{max-width:1200px;margin:0 auto;padding:20px}header{text-align:center;margin-bottom:3rem;color:#fff}header h1{font-size:3rem;margin-bottom:1rem;text-shadow:2px 2px 4px rgba(0,0,0,.3)}header p{font-size:1.2rem;opacity:.9}.features{display:grid;grid-template-columns:repeat(auto-fit,minmax(300px,1fr));gap:2rem;margin-bottom:3rem}.feature-card{background:#fff;padding:2rem;border-radius:12px;box-shadow:0 8px 32px #0000001a;text-align:center;transition:transform .3s ease,box-shadow .3s ease}.feature-card:hover{transform:translateY(-5px);box-shadow:0 12px 40px #00000026}.feature-card h3{color:#764ba2;margin-bottom:1rem;font-size:1.5rem}.interactive{text-align:center;background:#fff;padding:3rem;border-radius:12px;box-shadow:0 8px 32px #0000001a;margin-bottom:2rem}#clickBtn{background:linear-gradient(135deg,#667eea,#764ba2);color:#fff;border:none;padding:1rem 2rem;font-size:1.2rem;border-radius:8px;cursor:pointer;transition:transform .2s ease,box-shadow .2s ease}#clickBtn:hover{transform:scale(1.05);box-shadow:0 4px 20px #764ba266}#clickBtn:active{transform:scale(.98)}.message{margin-top:1.5rem;font-size:1.1rem;font-weight:700;min-height:30px;opacity:0;transition:opacity .3s ease}.message.show{opacity:1}footer{text-align:center;color:#fff;opacity:.8;margin-top:2rem}@media (max-width: 768px){.container{padding:10px}header h1{font-size:2rem}.features{grid-template-columns:1fr;gap:1rem}.feature-card{padding:1.5rem}.interactive{padding:2rem 1rem}}