style.css

/* layout */

@charset "UTF-8";

/* Reset CSS */
* {
    margin: 0;
    padding: 0;
    border: 0;
}

.container {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    height: 100vh;
}

body {
    background-color: #f0f0f0;
    font-family: sans-serif;
    font-size: 1em;
}

button {
    padding: 10px 20px;
    background-color: #fff;
    border: 1px solid #000;
    font-size: 1.2em;
}

.carta {
    width: 250px;
    height: 350px;
    background-color: #fff;
    margin-bottom: 50px;
    border-radius: 10px;
    box-shadow: rgba(0,0,0,0.4) 0px 2px 4px, rgba(0,0,0,0.3) 0px 7px 13px -3px, rgba(0,0,0,0.2) 0px -3px 0px inset ;
    position: relative;
}

.canto {
    position: absolute;
    font-size: 2em;
    text-align: center;
}

#supEsq {
    top: 20px;
    left: 15px;
}

#infDir {
    bottom: 25px;
    right: 15px;
    transform: rotate(180deg);
}

.centro {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100%;
    font-size: 6em;
}