[Unit]
Description=Mute audio when idle-inhibit is active

[Service]
Type=oneshot
ExecCondition=/bin/bash -c 'test -f ${XDG_RUNTIME_DIR}/idle-inhibit.pid && kill -0 $(cat ${XDG_RUNTIME_DIR}/idle-inhibit.pid)'
ExecStart=/usr/bin/wpctl set-mute @DEFAULT_AUDIO_SINK@ 1