c3 graph is not lining with other graph on chrome and safari browser

as can you see in this example https://jsfiddle.net/juanX/atw3edu0/6/i have two graph but is not lining with the another, i have chrome version 51.0.2704.84, the thing is that the firefox browser is working fine, i can't to set this with css because this graph will be to several dynamic graph

any idea of this issue?

var chart = c3.generate({
        bindto: '#chart',
    data: {
        columns: [
            ['data1', 1,52,65,89,200,566,774,200,566,300,700,123,654,852,159,321,756,821,654,123,951,753,926,45,126,345,821,821,921,13],
        ],
        types: {
            data2: 'spline'
        }
    },
    axis: {
        y: {
            padding: {bottom: 0},
            min: 0
        },
        x: {
            padding: {left: 0},
            min: 0,
            show: false
        }
    }

});

var chart = c3.generate({
        bindto: '#chart2',
    data: {
        columns: [
            ['data1', 300, 350, 300, 100, 80, 50],
        ],
        types: {
            data1: 'spline',
        }
    },
    axis: {
        y: {
            padding: {bottom: 0},
            min: 0
        },
        x: {
            padding: {left: 0},
            min: 0,
            show: false
        }
    }

});