The Confederate Constitution is a near copy of the US constitution with the exception of a few small details.

The Confederate president served a single 6 year term instead of (at the time) unlimited 4 year terms of the US. The Confederate president had a line veto (meaning he could veto a single line or section from a bill but put the rest through into law)

The Confederate constitution clearly outlined protections for slavery. As few as a few other things. you can read it here for your self

the Confederate Government could be as centralized or fragmented as the United States through interpretations of the law.

The Confederate Government did struggle with State Governments during the war over Manpower and supplies but that has less to do with the weakness of the Confederate Constitution but more to do with a newly established government struggling against entrenched and old state governments.

In many ways the Confederate Government was in a better position than the American colonies in 1776. The key difference being the American colonies gaining foreign recognition and the Confederates failing to get it.

The Confederate Government levied taxes and manpower, built factories, arsenals and shipyards. Built up a strong military and capable navy. It began constructing railroads but battlefield demands stripped away resources from infrastructure.

The Confederate Government ultimately failed in its duties as a Civil authority because President Jefferson Davis considered the War his utmost priority and not the public welfare. An understandable consideration.