How did the Croatian Spring call for greater autonomy within Yugoslavia?

The "Croatian Spring" (1969–1971) was a movement for cultural and national revival that emerged in response to the economic and political centralization of the Socialist Federal Republic of Yugoslavia.1

Encouraged by government-led efforts toward liberalization and decentralization in the 1960s, reformist Croatian leaders—most notably Miko Tripalo and Savka Dabčević-Kučar—sought to address grievances regarding the appropriation of the republic's income for investment elsewhere in the federation. The movement was expressed through the activities of the cultural organization Matica Hrvatska and evolved into explicit calls for greater Croatian autonomy.1

Ultimately, the movement was suppressed when Josip Broz Tito intervened, warning of the potential for civil war. He reimposed "democratic centralism" through a series of purges and trials that removed many of the movement's intellectual and political leaders. While the 1974 Yugoslav constitution later granted republics increased autonomy, they remained under the control of single-party regimes until the collapse of communist hegemony in the late 1980s.1