style.css

*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: normal Arial,sans-serif;
}

body{
    background-color: rgba(216, 5, 128, 0.63);
}

header h1{
    text-align: center;
    margin-top: 20px;
    margin-bottom: 20px;
    color: white;
}

.container{
    width: 500px;;
    height: 300px;
    display:flex;
    background-color: white;
    margin: 0 auto;
    flex-wrap: wrap;
    
    border-radius: 10px;
    box-shadow:  5px 5px 10px rgba(0, 0, 0, 0.322);
    flex-direction: column;
}

.tabuada {
    padding: 30px 10px;
    margin: 0 auto;
    
    
}
.tabuada p{
    color: rgba(216, 5, 128, 0.63);
}

input {
    width: 60px;
    height: 25px;
    border: 1px solid rgba(216, 5, 128, 0.63);
    border-radius: 10px;
    text-align: center;
    color: rgba(216, 5, 128, 0.63);
    
    
}

#btn{
    padding: 5px;
    border: none;
    background-color: rgba(216, 5, 128, 0.63);
    color: white;
    border-radius: 10px;;
}

#seltab{   
    width: 35%;
    margin: 0 auto;
    color:rgba(107, 2, 63, 0.877);
    text-align: center;
    border: 1px solid rgba(216, 5, 128, 0.63);
    border-radius: 10px;
}
option{
    
    margin: 0 auto;
    color:rgba(107, 2, 63, 0.877);
}
footer{
    margin-top: 30px;
    text-align: center;
    color: white;
    font-style: italic;
}