script.js

console.log('it`s working!')

let theme = localStorage.getItem('theme')

if(theme == null){
    setTheme('pop-os-dark')
}else{
    setTheme(theme)
}

let themeDots = document.getElementsByClassName('theme-dot')

for(var i=0; themeDots.length > i; i++){
    themeDots[i].addEventListener('click', function(){
        let mode = this.dataset.mode
        console.log('Option clicked: ', mode)
        setTheme(mode)
    })
}


function setTheme(mode) {
    if(mode == 'pop-os-dark'){
        document.getElementById('theme-style').href = 'pop-os-dark.css'
    }

    if(mode == 'pop-os-light'){
        document.getElementById('theme-style').href = 'style.css'
    }

    if(mode == 'blue'){
        document.getElementById('theme-style').href = 'blue.css'
    }

    if(mode == 'green'){
        document.getElementById('theme-style').href = 'green.css'
    }

    if(mode == 'purple'){
        document.getElementById('theme-style').href = 'purple.css'
    }

    localStorage.setItem('theme', mode)
}