A customised built-in* number and range input with both the property .normal
and the CSS property --normal, which describes the position of the handle
in the range 0-1 regardless of the values of min and max,
permitting the application of handle-position-based styles.
Also adds the law attribute. A fader law adjusts the interpolation
of an input's value over its range. An input with law="log-36db",
for example, is dB-linear in its top portion down to -36dB, and gain-linear
down to -∞dB.
*Customised built-in behaviour is polyfilled in Safari.
Test input in the light DOM