* {
    margin: 0;
    padding: 0;

    box-sizing: border-box;

    /* h1 ~ h6 */
    font-size: inherit;
    font-weight: inherit;

    /* em i */
    font-style: inherit;

    /* ol ul */
    list-style: none;
}

a {
    color: inherit;
    text-decoration: unset;
}

iframe {
    border: unset;
}

button {
    all: unset;

    display: inline-block;

    box-sizing: border-box;

    cursor: pointer;
}

/* keep */
b {
    font-weight: bold;
}

/* fix */
a > img {
    /*  
    Extra 4px at the bottom of html <img> 
    https://gaurav5430.medium.com/extra-4px-at-the-bottom-of-html-img-8807a7ab0ca2
    */
    vertical-align: text-bottom;
}