Q:

CSS for Individual Columns Scroll with Horizontal Scrolling

I am building a UI component that has columns of information. Each column needs to be individually scrollable. I have found that on SO.com before, but I am having trouble reconciling that with the other requirement - that the page scrolls horizontally to show columns that do not fit on screen.
I have the horizontal scrolling working but cannot get it to work in conjunction with individual column scrolling. The code:
#board {
    float: left;
    height: 98%;
    max-height: 98%;
    width: 4300px; /*smaller than columns to force horizontal scroll */
    margin: auto;
    border: none;
    overflow-x: scroll;
}

#columns {
    height: 98%;
    float: left;
    width: 4800px; /* need this much width */
    margin: auto;
    border: none;
    overflow-x:auto;
}

.column {
    float: left;
    padding-bottom: 50px;
    width: 240px;
    height: 100%;
    max-height: 100%;
    padding: 5px;
    padding-bottom: 100px;
    margin-left: 5px;
    overflow-y: auto;
    overflow-x: hidden;
}

<div id="board">
    <div id="columns">
        <div id="col1" class="column">
            <div class="card"> ...content... </div>
            <div class="card"> ...content... </div>
            <div class="card"> ...content... </div>
            <div class="card"> ...content... </div>
        </div>
        <div id="col2" class="column">
            <div class="card"> ...content... </div>
            <div class="card"> ...content... </div>
            <div class="card"> ...content... </div>
            <div class="card"> ...content... </div>
        </div>
        <!-- 12-16 more columns -->
    </div>
</div>

Edited to fix id vs class issue in html.

A:

I tried to simplify your code to only include what's necessary to solve your problem, but it should work. There are a couple errors in your CSS too: you have a style for #boards but the outer container has a class boards not an id, and you have a style for #columns but the middle inner container has an id of positions. 

html,
body {
  height: 100%;
  margin: 0;
  padding: 0;
}
.board {
  height: 100%;
  width: 200px;
  overflow-x: scroll;
}
#columns {
  height: 100%;
  width: 500px;
  white-space: nowrap;
}
.column {
  vertical-align: top;
  height: 100%;
  display: inline-block;
  width: 150px;
  overflow-y: auto;
  overflow-x: hidden;
}
.card {
  height: 200px;
  background: #F00;
  margin-bottom: 5px;
}
<div class="board">
  <div id="columns">
    <div class="column">
      <div class="card">...content...</div>
      <div class="card">...content...</div>
      <div class="card">...content...</div>
      <div class="card">...content...</div>
    </div>
    <div class="column">
      <div class="card">...content...</div>
      <div class="card">...content...</div>
      <div class="card">...content...</div>
    </div>
    <div class="column">
      <div class="card">...content...</div>
    </div>

