I hope someone can help me, i'm stuck. What I want to do is that I have a set of button. All I want is that when I hover on Button SPA, the buttons Pro1, Proii and Proiii changes color. I know since the div are nested maybe that is why the code is not working or you can provide me with some alternate Solution.

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
<%--<link href="Scripts\table.css" rel="stylesheet" type="text/css" />--%>
<link/ rel="stylesheet" href="https://www.w3schools.com/w3css/4/w3.css"/>
<style>
.custom_button {
background-color: black;
color: white;
padding: 10px 10px;
border: 1px solid black;
text-decoration: none;
}
#btnSpa:hover ~ #btnPro1,
#btnSpa:hover ~ #btnProii,
#btnSpa:hover ~ #btnProiii {
background-color: white;
color: black;
padding: 10px 10px;
border: 1px solid black;
text-decoration: none;
}
.container {
height: 200px;
position: relative;
border: 3px solid green;
}
.superleft {
margin: 0;
position: absolute;
top: 50%;
left: 10%;
-ms-transform: translate(-50%, -50%);
transform: translate(-50%, -50%);
}
.left {
margin: 0;
position: absolute;
top: 25%;
left: 25%;
-ms-transform: translate(-50%, -50%);
transform: translate(-50%, -50%);
}
.leftt {
margin: 0;
position: absolute;
top: 50%;
left: 25%;
-ms-transform: translate(-50%, -50%);
transform: translate(-50%, -50%);
}
.leftdown {
margin: 0;
position: absolute;
top: 75%;
left: 25%;
-ms-transform: translate(-50%, -50%);
transform: translate(-50%, -50%);
}
.middletop {
margin: 0;
position: absolute;
top: 25%;
left: 50%;
-ms-transform: translate(-50%, -50%);
transform: translate(-50%, -50%);
}
.middle {
margin: 0;
position: absolute;
top: 50%;
left: 50%;
-ms-transform: translate(-50%, -50%);
transform: translate(-50%, -50%);
}
.middledown {
margin: 0;
position: absolute;
top: 75%;
left: 50%;
-ms-transform: translate(-50%, -50%);
transform: translate(-50%, -50%);
}
</style>
</head>
<body>
<form id="form1" runat="server">
<div class="container">
<div class="superleft">
<asp:Button ID="btnSpa" runat="server" class="custom_button" Text="SPA"/>
</div>
<div class="left">
<asp:Button ID="btnPro1" runat="server" class="custom_button" Text="Pro1" />
</div>
<div class="leftt">
<asp:Button ID="btnProii" runat="server" class="custom_button" Text="Proii"/>
</div>
<div class="leftdown">
<asp:Button ID="btnProiii" runat="server" class="custom_button" Text="Proiii"/>
</div>
<div class="middletop">
<asp:Button ID="btnPro2" runat="server" class="custom_button" Text="Pro2" />
</div>
<div class="middle">
<asp:Button ID="btnPro2i" runat="server" class="custom_button" Text="Pro2i" />
</div>
<div class="middledown">
<asp:Button ID="btnPro2ii" runat="server" class="custom_button" Text="Pro2ii" />
</div>
</div>
</form>
</body>
</html>