Q:

Tooltips style in google charts

I would like to know if it is possible to change the font color of DEFAULT tooltips in a google line chart. 
I want to do this by changing css style like this:
<style>

    .google-visualization-tooltip { 

            width: 150px ! important;
            border: none ! important;
            border-radius: 21px ! important;
            background-color: rgb(30, 50, 230)!important;
            position: absolute ! important;
            box-shadow: 7px 7px 5px 0px rgba(50, 50, 50, 0.75) ! important;
            background: -moz-linear-gradient(30deg, rgb(30, 50, 230) 30%, rgb(90, 140, 250) 70%) ! important;
            background: -webkit-linear-gradient(30deg, rgb(30, 50, 230) 30%, rgb(90, 140, 250) 70%) ! important;
            background: -o-linear-gradient(30deg, rgb(30, 50, 230) 30%, rgb(90, 140, 250) 70%) ! important;
            background: -ms-linear-gradient(30deg, rgb(30, 50, 230) 30%, rgb(90, 140, 250) 70%) ! important;
            background: linear-gradient(120deg, rgb(30, 50, 230) 30%, rgb(90, 140, 250) 70%) ! important;
            font-size:  10px ! important;

          }

    </style>

All of this css lines work well but I have not found the font color param until now.  
By the way, if I modify "tooltip.textStyle" param of Line Chart API the font color changes but the CSS code mentioned above become unusable. 
Thanks! 

A:

In addition to the answer given from the same user that asked...
You will have to set 
tooltip: { isHtml: true }

at the chart options for the CSS to work. 
Please read the official Google Charts documentation: customizing tooltip content

A:

Summing up the answers given by people above. :)  
Enable the tooltip to be handled by the HTML by writing this code in your options of google charts CODE: tooltip: { isHtml: true } (,) add a comma if needed. :) 
Now you can style tooltip using HTML and css. :) 
/CSS Styling/
To style the tooltip box :
div.google-visualization-tooltip {}

To style the content like font size, color, etc
div.google-visualization-tooltip > ul > li > span {}

Use ! important whenever needed ;)

A:

I got it! 
I needed to insert this lines in style tag. 
div.google-visualization-tooltip > ul > li > span {
color: #ff0000 ! important;

