html{font-size:12px; font-size:62.5%; /* 10÷16=62.5% */}
@media screen and (max-width: 1920px) {
    html { font-size: 100%;}
}
@media screen and (max-width: 1336px) {
    html { font-size: 80%;}
}
@media screen and (max-width: 1200px) {
    html { font-size: 62.5%;}
}
@media screen and (max-width: 1000px) {
    html { font-size: 10px;}
}
@media screen and (max-width: 800px) {
    html { font-size: 8px;}
}
@media screen and (max-width: 700px) {
    html { font-size: 7px;}
}
@media screen and (max-width: 600px) {
    html { font-size: 6px;}
}