.splitpanel-vertical { display: flex; flex-direction: row; overflow: auto; } .splitpanel-vertical > *:first-child { max-width: calc(100% - 18px); } .splitpanel-vertical > * { flex: 0 0 auto; overflow: auto; } .splitpanel-vertical > *:last-child { flex: 1 1 auto; overflow: auto; } .splitpanel-horizontal { display: flex; flex-direction: column; overflow: auto; } .splitpanel-horizontal > *:first-child { max-height: calc(100% - 18px); } .splitpanel-horizontal > * { flex: 0 0 auto; overflow: auto; } .splitpanel-horizontal > *:last-child { flex: 1 1 auto; overflow: auto; } .splitter-vertical { flex: 0 0 auto; width: 18px; background: url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAgAAAAhCAQAAABOpSL+AAAAIklEQVR4AWMwbb/PdR+JZDD9f1/oPhI5sgVGBSruc9xHIgGdSQqqQJGkRgAAAABJRU5ErkJggg==') center center no-repeat #535353; cursor: col-resize; } .splitter-horizontal { flex: 0 0 auto; height: 18px; background: url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAACEAAAAICAQAAADdTl4aAAAAIElEQVQoz2MwrTD9TxFsZ7jPcV+IIsjFQAUw6hFqegQA+xzRHT2p7pEAAAAASUVORK5CYII=') center center no-repeat #535353; cursor: row-resize; }