Keep interpolation in var CSS function #159

Job	Run time
Static analysis	24s
Dart tests \| Dart stable \| ubuntu-latest	1m 9s
Node tests \| Dart stable \| Node 18 \| ubuntu-latest	1m 5s
Dart tests \| Dart stable \| windows-latest	1m 35s
Node tests \| Dart stable \| Node 18 \| windows-latest	1m 59s
Dart tests \| Dart stable \| macos-latest	2m 26s
Node tests \| Dart stable \| Node 18 \| macos-latest	2m 16s
Node tests \| Dart stable \| Node 16 \| ubuntu-latest	1m 3s
Node tests \| Dart stable \| Node 14 \| ubuntu-latest	1m 8s
Node tests \| Dart dev \| Node \| ubuntu-latest	59s
Sanity checks	0s
Deploy Github: Linux	0s
Deploy npm	0s
Deploy Homebrew	0s
Deploy Pub	0s
Deploy Github: Windows	0s
Deploy Github: Mac OS	0s
	14m 4s

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