Set z-index for tooltip in css - #564

c3.css

@@ -148,6 +148,9 @@
 
 /*-- Tooltip --*/
 
+.c3-tooltip-container {
+  z-index: 10;
+}
 .c3-tooltip {
   border-collapse:collapse;
   border-spacing:0;

c3.js

@@ -3391,10 +3391,10 @@
         var $$ = this, config = $$.config, i;
         $$.tooltip = $$.selectChart
             .style("position", "relative")
-            .append("div")
+          .append("div")
+            .attr('class', CLASS.tooltipContainer)
             .style("position", "absolute")
             .style("pointer-events", "none")
-            .style("z-index", "10")
             .style("display", "none");
         // Show tooltip if needed
         if (config.tooltip_init_show) {
@@ -5207,6 +5207,7 @@
         defocused: 'c3-defocused',
         region: 'c3-region',
         regions: 'c3-regions',
+        tooltipContainer: 'c3-tooltip-container',
         tooltip: 'c3-tooltip',
         tooltipName: 'c3-tooltip-name',
         shape: 'c3-shape',

c3.min.css

-.c3 svg{font:10px sans-serif}.c3 line,.c3 path{fill:none;stroke:#000}.c3 text{-webkit-user-select:none;-moz-user-select:none;user-select:none}.c3-bars path,.c3-event-rect,.c3-legend-item-tile,.c3-xgrid-focus,.c3-ygrid{shape-rendering:crispEdges}.c3-chart-arc path{stroke:#fff}.c3-chart-arc text{fill:#fff;font-size:13px}.c3-grid line{stroke:#aaa}.c3-grid text{fill:#aaa}.c3-xgrid,.c3-ygrid{stroke-dasharray:3 3}.c3-text.c3-empty{fill:gray;font-size:2em}.c3-line{stroke-width:1px}.c3-circle._expanded_{stroke-width:1px;stroke:#fff}.c3-selected-circle{fill:#fff;stroke-width:2px}.c3-bar{stroke-width:0}.c3-bar._expanded_{fill-opacity:.75}.c3-chart-arcs-title{font-size:1.3em}.c3-target.c3-focused{opacity:1}.c3-target.c3-focused path.c3-line,.c3-target.c3-focused path.c3-step{stroke-width:2px}.c3-target.c3-defocused{opacity:.3!important}.c3-region{fill:#4682b4;fill-opacity:.1}.c3-brush .extent{fill-opacity:.1}.c3-legend-item{font-size:12px}.c3-legend-background{opacity:.75;fill:#fff;stroke:#d3d3d3;stroke-width:1}.c3-tooltip{border-collapse:collapse;border-spacing:0;background-color:#fff;empty-cells:show;-webkit-box-shadow:7px 7px 12px -9px #777;-moz-box-shadow:7px 7px 12px -9px #777;box-shadow:7px 7px 12px -9px #777;opacity:.9}.c3-tooltip tr{border:1px solid #CCC}.c3-tooltip th{background-color:#aaa;font-size:14px;padding:2px 5px;text-align:left;color:#FFF}.c3-tooltip td{font-size:13px;padding:3px 6px;background-color:#fff;border-left:1px dotted #999}.c3-tooltip td>span{display:inline-block;width:10px;height:10px;margin-right:6px}.c3-tooltip td.value{text-align:right}.c3-area{stroke-width:0;opacity:.2}.c3-chart-arcs .c3-chart-arcs-background{fill:#e0e0e0;stroke:none}.c3-chart-arcs .c3-chart-arcs-gauge-unit{fill:#000;font-size:16px}.c3-chart-arcs .c3-chart-arcs-gauge-max,.c3-chart-arcs .c3-chart-arcs-gauge-min{fill:#777}.c3-chart-arc .c3-gauge-value{fill:#000;font-size:28px}
\ No newline at end of file
+.c3 svg{font:10px sans-serif}.c3 line,.c3 path{fill:none;stroke:#000}.c3 text{-webkit-user-select:none;-moz-user-select:none;user-select:none}.c3-bars path,.c3-event-rect,.c3-legend-item-tile,.c3-xgrid-focus,.c3-ygrid{shape-rendering:crispEdges}.c3-chart-arc path{stroke:#fff}.c3-chart-arc text{fill:#fff;font-size:13px}.c3-grid line{stroke:#aaa}.c3-grid text{fill:#aaa}.c3-xgrid,.c3-ygrid{stroke-dasharray:3 3}.c3-text.c3-empty{fill:gray;font-size:2em}.c3-line{stroke-width:1px}.c3-circle._expanded_{stroke-width:1px;stroke:#fff}.c3-selected-circle{fill:#fff;stroke-width:2px}.c3-bar{stroke-width:0}.c3-bar._expanded_{fill-opacity:.75}.c3-chart-arcs-title{font-size:1.3em}.c3-target.c3-focused{opacity:1}.c3-target.c3-focused path.c3-line,.c3-target.c3-focused path.c3-step{stroke-width:2px}.c3-target.c3-defocused{opacity:.3!important}.c3-region{fill:#4682b4;fill-opacity:.1}.c3-brush .extent{fill-opacity:.1}.c3-legend-item{font-size:12px}.c3-legend-background{opacity:.75;fill:#fff;stroke:#d3d3d3;stroke-width:1}.c3-tooltip-container{z-index:10}.c3-tooltip{border-collapse:collapse;border-spacing:0;background-color:#fff;empty-cells:show;-webkit-box-shadow:7px 7px 12px -9px #777;-moz-box-shadow:7px 7px 12px -9px #777;box-shadow:7px 7px 12px -9px #777;opacity:.9}.c3-tooltip tr{border:1px solid #CCC}.c3-tooltip th{background-color:#aaa;font-size:14px;padding:2px 5px;text-align:left;color:#FFF}.c3-tooltip td{font-size:13px;padding:3px 6px;background-color:#fff;border-left:1px dotted #999}.c3-tooltip td>span{display:inline-block;width:10px;height:10px;margin-right:6px}.c3-tooltip td.value{text-align:right}.c3-area{stroke-width:0;opacity:.2}.c3-chart-arcs .c3-chart-arcs-background{fill:#e0e0e0;stroke:none}.c3-chart-arcs .c3-chart-arcs-gauge-unit{fill:#000;font-size:16px}.c3-chart-arcs .c3-chart-arcs-gauge-max,.c3-chart-arcs .c3-chart-arcs-gauge-min{fill:#777}.c3-chart-arc .c3-gauge-value{fill:#000;font-size:28px}
\ No newline at end of file

src/class.js

@@ -26,6 +26,7 @@ var CLASS = c3_chart_internal_fn.CLASS = {
     defocused: 'c3-defocused',
     region: 'c3-region',
     regions: 'c3-regions',
+    tooltipContainer: 'c3-tooltip-container',
     tooltip: 'c3-tooltip',
     tooltipName: 'c3-tooltip-name',
     shape: 'c3-shape',

src/tooltip.js

@@ -2,10 +2,10 @@ c3_chart_internal_fn.initTooltip = function () {
     var $$ = this, config = $$.config, i;
     $$.tooltip = $$.selectChart
         .style("position", "relative")
-        .append("div")
+      .append("div")
+        .attr('class', CLASS.tooltipContainer)
         .style("position", "absolute")
         .style("pointer-events", "none")
-        .style("z-index", "10")
         .style("display", "none");
     // Show tooltip if needed
     if (config.tooltip_init_show) {