html, body {
    margin: 0;         /* Remove default body margin */
    padding: 0;
    height: 100%;
    width: 100%;
    overflow: hidden;  /* Prevents scrollbars on the main page */
}

iframe {
    display: block;    /* Iframes are inline by default */
    border: none;      /* Remove default border */
    width: 100vw;      /* 100% of the viewport width */
    height: 100vh;     /* 100% of the viewport height */
    position: absolute; /* Alternative to vw/vh for full viewport coverage */
    top: 0;
    left: 0;
}