Hi,
I’m trying to force in my theme.yaml file the corner radius to 0px
whith this code
ha-card-border-radius: “0px”
with no results.
What is wrong?
Thankyou.
Stef
note: I’m running an old version of HA 2021.9.7.
Update! 
Read only after you updated!
My guess is, you need to set !important on your css definition, otherwise it won’t work. I can’t say, if it works or not, as I can’t try and experiment with such an old version, too much has changed since then…sorry!
going to.
Rasp 5 already run a test version of my automations.
The version is old because I run a proprietary dietpi distribution , anyway it is scheduled!
Thankyou
That’s great, it really is an old version. 
Have you tried the !important in your css definition?
ehm, actually I use his file to switch to dark mode after sunset
Dark:
# Header:
app-header-background-color: rgb(23, 23, 23)
app-header-text-color: rgb(198, 203, 210)
# Main Interface Colors
<…omissis…>
# Cards
card-background-color: rgb(32, 33, 36)
ha-card-border-radius: “0px”
ha-card-box-shadow: 1px 1px 5px 0px rgb(12, 12, 14)
paper-dialog-background-color: var(–card-background-color)
paper-listbox-background-color: var(–card-background-color)
paper-card-background-color: var(–card-background-color)
# Switches
switch-checked-button-color: rgb(255, 179, 26)
switch-checked-track-color: rgb(255, 179, 26)
<…etcetera…>
Light:
### Main Interface Colors ###
primary-color: “#395274”
<…etcetera…>
This is your definition,
try with
ha-card-border-radius: 0px !important