and when i use animationEnabled: true, animationDuration: 1000, then my indexLabel font show very small like this screenshot http://prntscr.com/eqbxg1 and whithout use this animationEnabled http://prntscr.com/eqby67 kindly do need full for me and too much thanks for yours api
Sorry, we were unable to reproduce the issue regarding change in the size of indexLabel at our end. Can you please create a jsfiddle reproducing the issue and also share browser and OS details along with versions where you are facing this issue.
Regarding your query about placing indexLabels at the bottom, this feature is not available out of the box as of now. However you can follow this workaround.
You can set highlightEnabled to false at dataSeries or dataPoint level to disable highlighting of the dataPoints. And for setting the opacity you can use fillOpacity at dataSeries level or rgba value with color at dataSeries or dataPoint level.