set_fzf_theme() {
    local appearance="$1"

    # Detect the current system appearance (Light or Dark mode) for Linux and macOS
    if [[ -z "$appearance" ]]; then
        if [[ "$OSTYPE" == "darwin"* ]]; then
            # macOS
            appearance=$(defaults read -g AppleInterfaceStyle 2>/dev/null)
        elif [[ "$OSTYPE" == "linux-gnu"* ]]; then
            # Linux (assuming GNOME)
            appearance=$(gsettings get org.gnome.desktop.interface gtk-theme 2>/dev/null)
        else
            # Default to Dark mode if the system is not recognized
            appearance="Dark"
        fi
    fi

    # Set fzf theme based on appearance
    if [[ $appearance == *"Dark"* || -n "$TMUX" ]]; then
        FZF_DEFAULT_OPTS="--color=bg+:#1e1e1e,bg:#1e1e1e,spinner:#d33682,hl:#b58900,fg:#ffffff,header:#d33682,info:#268bd2,pointer:#859900,marker:#859900,fg+:#ffffff,prompt:#268bd2,hl+:#b58900"
    else
        FZF_DEFAULT_OPTS="--color=bg+:#fdf6e3,bg:#fdf6e3,spinner:#d33682,hl:#b58900,fg:#657b83,header:#d33682,info:#268bd2,pointer:#859900,marker:#859900,fg+:#657b83,prompt:#268bd2,hl+:#b58900"
    fi

    # export FZF_DEFAULT_OPTS

    echo "$FZF_DEFAULT_OPTS"
}

# Call the function to set FZF_DEFAULT_OPTS
set_fzf_theme "$1"