把页面主体内容限定在安全区内

    padding-top: constant(safe-area-inset-top);
    padding-top: env(safe-area-inset-top);
    padding-bottom: constant(safe-area-inset-bottom);
    padding-bottom: env(safe-area-inset-bottom);
    padding-left: constant(safe-area-inset-left);
    padding-left: env(safe-area-inset-left);
    padding-right: constant(safe-area-inset-right);
    padding-right: env(safe-area-inset-right);