.config/fontconfig/fonts.conf

fonts.conf

<?xml version='1.0'?>
<!DOCTYPE fontconfig SYSTEM 'fonts.dtd'>
<fontconfig>
    <!-- Default font (no fc-match pattern) -->
    <match>
        <edit mode="prepend" name="family">
            <string>Noto Sans</string>
        </edit>
    </match>
    <!-- Default font for the ja_JP locale (no fc-match pattern) -->
    <match>
        <test compare="contains" name="lang">
            <string>zh</string>
        </test>
        <edit mode="prepend" name="family">
            <string>Sarasa UI SC</string>
        </edit>
    </match>
    <!-- Default sans-serif font -->
    <match target="pattern">
        <test qual="any" name="family">
            <string>sans-serif</string>
        </test>
        <!--<test qual="any" name="lang"><string>ja</string></test>-->
        <edit name="family" mode="prepend" binding="same">
            <string>Sarasa UI SC</string>
        </edit>
    </match>
    <!-- Default serif fonts -->
    <match target="pattern">
        <test qual="any" name="family">
            <string>serif</string>
        </test>
        <edit name="family" mode="prepend" binding="same">
            <string>Noto Serif</string>
        </edit>
    </match>
    <!-- Default monospace fonts -->
    <match target="pattern">
        <test qual="any" name="family">
            <string>monospace</string>
        </test>
        <edit name="family" mode="prepend" binding="same">
            <string>Sarasa Mono SC</string>
        </edit>
    </match>
    <!-- Fallback fonts preference order -->
    <alias>
        <family>sans-serif</family>
        <prefer>
            <family>Noto Sans CJK SC</family>
            <family>Noto Sans</family>
            <family>Open Sans</family>
        </prefer>
    </alias>
    <alias>
        <family>serif</family>
        <prefer>
            <family>Noto Serif</family>
        </prefer>
    </alias>
    <alias>
        <family>monospace</family>
        <prefer>
            <family>Sarasa Mono SC</family>
        </prefer>
    </alias>
    <dir>~/.fonts</dir>
</fontconfig>