/* general reset */
*{
    margin:0;
    padding:0;
    box-sizing:border-box;
}

/* page width */
body{
    font-family: Arial, sans-serif;
    padding:20px;
}

/* responsive images */
img{
    max-width:100%;
    height:auto;
}

/* flexible layout */
.container{
    width:90%;
    max-width:1200px;
    margin:auto;
}

/* cards or sections */
.card{
    width:300px;
    margin:10px;
}

/* mobile responsive */
@media (max-width:768px){

    body{
        padding:10px;
    }

    .container{
        width:100%;
    }

    .card{
        width:100%;
    }

    h1,h2,h3,p{
        text-align:center;
    }

    table{
        display:block;
        overflow-x:auto;
    }

}