在核心php项目中动态LTR到RTL

I have a website written in core php , I want to add Arabic language . So i have to make LTR to RTL dynamically . But how can I do it ? do i have to change all css code and rewrtie them all for RTL or is there anythins else ? I searched a lot and found rtlcss but how can i implement them easily ?

all of the following code is pure examples and will be shortened

index.html

<html>
    <head>
        <link rel="stylesheet" type="text/css" href="/css/main.min.css">
        <!-- this should be included if the user's language is RTL -->
        <link rel="stylesheet" type="text/css" href="/css/rtl.min.css">
    </head>
    <body></body>
</html>

main.min.css

/* here goes all css codes that goes with all pages */
body {
  padding-top: 50px;
}
div.tab-content {
  padding-top: 20px;
}
.main-panel {
    float: right;
}

rtl.min.css

/* this will override the previous css rule */
.main-panel {
    float: left;
}
body {
    direction: rtl;
    margin: 0;
}

you can also join them together in one file and in your php file add class to body .rtl and in your css file ( of course at the end ) add css rules like:

body.rtl {
    direction: rtl;
}

but for sake of lighter css files and since many users will not benefit from the RTL rules i would advise using the first example

there is some online converter to transform ltr based css code to rtl based css code . Then i added different css for different choice of user . SO there will be two css file .