问为什么我的CSS类不能工作？

EN

<div id="main">
    <div id="calendar">
    <div class="column" id="time_slots">
    </div>

        <div class="column" id="day1">
            <div class="route_container">
                <div class="date"></div>
                <button class="add_route" name="add_route" onclick="">Add New Route - 1</button>
                <div class = "truck" id="day1_route1">
                    <div class="8-10">8-10 AM today</div>//want css for this
                    <div class="10-12">10-12 AM</div>
                    <div class="12-2">12-2 AM</div>
                    <div class="2-4">2-4 AM</div>
                    <div class="4-6">4-6 AM</div>
                </div>
            </div>
        </div>
            ...etc...

.label
{
    width:20px;
}

.table
{
    font-size: 1.2em;
}
#main
{
    border-style: solid;
    border-width: 1px;
    border-color: black; 
    width:97%;
    height:900px;
    margin:auto;
    overflow: auto; 
    white-space: nowrap;

}
h2
{
    font-size: 24px;
}
#calendar
{
    padding:1%;

}
.column
{
    border-style: solid;
    border-width: 1px;
    border-color: black; 
    min-width:10%;
    max-width:100%;
    height:800px;
    display: inline-block;
    overflow: auto;
    padding:5px;
    font-size: 0px;


}
.header
{
    padding:0;
    margin:0;
    text-align: center; 
    font-style: bold; 
}

.truck
{
    width:200px;
    border-style: solid;
    border-width: 1px;
    border-color: black; 
    display:inline-block;
    margin:auto;
    font-size: 16px;


}

.column#time_slots
{
    width:5%;
    min-width:5%;
    max-width: 10%; 
}
.date
{
    text-align: center;
    width:100%;
}
.column button
{
    display:block;
    width:100%;
    width:100%;
    border-style: solid;
    border-width: 1px;
    border-color: black; 
    font-size: 16px; 
}
.full_time
{
    display: none; 
}
.8-10
{
    border-style: solid;
    border-width: 1px;
    border-color: black; 
    width:100px;
    height:18px;

    font-size: 24px;    
}

.8-10, .10-12, .12-2, .2-4, .4-6
    {
        border-style: solid;
        border-width: 1px;
        border-color: black; 
        width:100px;
        height:18px;

        font-size: 24px;    
    }