body{
    font-family: 'Segoe UI', Arial, sans-serif;
    background: linear-gradient(135deg,#4facfe,#00f2fe);
    height:100vh;
    margin:0;
    display:flex;
    flex-direction:column;
    justify-content:center;
    align-items:center;
}

#c{
    font-size:80px;
    font-weight:bold;
    color:#333;
    margin-bottom:40px;
}

.tt{
    display:flex;
    gap:20px;
}

button{
    padding:12px 20px;
    font-size:15px;
    border:none;
    border-radius:6px;
    cursor:pointer;
    color:white;
    transition:0.3s;
}

#d{
    background:#e74c3c;
}

#i{
    background:#2ecc71;
}

#r{
    background:#3498db;
}

button:hover{
    transform:scale(1.08);
    opacity:0.9;
}