Capricorn and Libra are both cardinal signs, which means neither one is naturally content to sit back and let life happen to them. They initiate. They plan. The trouble is, they often want to initiate the same conversation at the same time, from different directions, and neither wants to be the one who follows. Picture them choosing an apartment together: Capricorn has already priced out three neighborhoods based on resale value and commute time, while Libra is asking whether the light in the second bedroom feels right and whether the neighbors seem kind. Both are legitimate ways of making a big decision. Both parties will insist theirs is the sensible one.
What softens this is the pull between Saturn and Venus. Capricorn's ruler wants proof, structure, a plan that holds up under pressure. Libra's ruler wants beauty, ease, a relationship that feels good to be inside of. Left alone, Capricorn can turn a household into a project with deadlines, and Libra can avoid a hard conversation for weeks in the name of peace. Together, though, Libra can talk Capricorn into slowing down enough to enjoy what they have built, and Capricorn can give Libra's ideals an actual scaffolding to stand on. Libra brings the charm and diplomacy that smooths Capricorn's blunt edges in social settings; Capricorn brings the follow-through that turns Libra's beautiful intentions into something real.
The friction worth naming honestly is around control. Both signs like to be the one steering, even if Libra steers by suggestion and Capricorn steers by quiet decision. If they learn to trade the wheel instead of wrestling for it, this pairing builds something sturdy and genuinely graceful, which is rarer than it sounds.