How to use templates in a custom panel? Or override state card width

i’ve made a custom panel using this guide:
https://home-assistant.io/developers/frontend_creating_custom_panels/

It works, and shows “Hello…”, however I have no clue on how to use templates, similar to how I use them in a custom state card. I tried inserting one of my sensors using both of these, but they return nothing:

{{ sensor.dht1_temperature }}
{{ states.sensor.dht1_temperature }}
{{ sensor.dht1_temperature.attributes }}
{{ states.sensor.dht1_temperature.attributes }}

I want to try to use the template-tag like in my state card, where stateObj is the entity, but since I don’t know how to access the entity, I don’t know where to start.

<template is="dom-repeat" items="{{stateObj.attributes.groupList}}" as="item">

The reason I want to use a custom panel is to show a table that fills the screen, instead of in a state card. I tried to style it, but it was very hard. I also tried Custom UI state-card by andrey-git but I didn’t get it working with setting the card widths and found it too complex for what I need.

If I could just override the styles of the statecard with !important or some javascript, and make it 100%, that would be even easier.

There needs to be more examples on Custom Panels for n00bs like me… :slight_smile: