Develop Reference

CSS Grid - Highlight cells up to the hovered cell

In a grid, I want to highlight group of cells - a rectangle shape - starting from top left cell up to the cell under the mouse position.
Let's say our grid initially looks like this:
.grid {
display: grid;
grid-template-columns: repeat(5, 50px);
grid-template-rows: repeat(5, 50px);
gap: 5px;
}
.grid-item {
display: flex;
justify-content: center;
align-items: center;
background: lightgray;
}
<div class="grid">
<div class="grid-item">1</div>
<div class="grid-item">2</div>
<div class="grid-item">3</div>
<div class="grid-item">4</div>
<div class="grid-item">5</div>
<div class="grid-item">6</div>
<div class="grid-item">7</div>
<div class="grid-item">8</div>
<div class="grid-item">9</div>
<div class="grid-item">10</div>
<div class="grid-item">11</div>
<div class="grid-item">12</div>
<div class="grid-item">13</div>
<div class="grid-item">14</div>
<div class="grid-item">15</div>
<div class="grid-item">16</div>
<div class="grid-item">17</div>
<div class="grid-item">18</div>
<div class="grid-item">19</div>
<div class="grid-item">20</div>
<div class="grid-item">21</div>
<div class="grid-item">22</div>
<div class="grid-item">23</div>
<div class="grid-item">24</div>
<div class="grid-item">25</div>
</div>
And now the user hovers with the mouse over cell number 18. The grid should look like this now:
.grid {
display: grid;
grid-template-columns: repeat(5, 50px);
grid-template-rows: repeat(5, 50px);
gap: 5px;
}
.grid-item {
display: flex;
justify-content: center;
align-items: center;
background: lightgray;
}
.grid-item-blue {
background: lightblue;
}
<div class="grid">
<div class="grid-item grid-item-blue">1</div>
<div class="grid-item grid-item-blue">2</div>
<div class="grid-item grid-item-blue">3</div>
<div class="grid-item">4</div>
<div class="grid-item">5</div>
<div class="grid-item grid-item-blue">6</div>
<div class="grid-item grid-item-blue">7</div>
<div class="grid-item grid-item-blue">8</div>
<div class="grid-item">9</div>
<div class="grid-item">10</div>
<div class="grid-item grid-item-blue">11</div>
<div class="grid-item grid-item-blue">12</div>
<div class="grid-item grid-item-blue">13</div>
<div class="grid-item">14</div>
<div class="grid-item">15</div>
<div class="grid-item grid-item-blue">16</div>
<div class="grid-item grid-item-blue">17</div>
<div class="grid-item grid-item-blue">18</div>
<div class="grid-item">19</div>
<div class="grid-item">20</div>
<div class="grid-item">21</div>
<div class="grid-item">22</div>
<div class="grid-item">23</div>
<div class="grid-item">24</div>
<div class="grid-item">25</div>
</div>
I prefer css solution.
Is is possible using css only? If not, how would you do this in JS?

Here's a pure css Idea if you don't mind nesting the content on more level just to put it over the fake background.
.grid {
overflow:hidden;
display: grid;
grid-template-columns: repeat(5, 50px);
grid-template-rows: repeat(5, 50px);
gap: 5px;
}
.grid-item {
background: lightgray;
position: relative;
display: flex;
}
.grid-item>span {
z-index: 2;
width: 100%;
height: 100%;
display: flex;
justify-content: center;
align-items: center;
}
.grid-item:hover:before {
position: absolute;
content: '';
background: linear-gradient(to left,#ff000000 0px 50px,#ffffff 50px 55px) 0 0/55px, linear-gradient(to top,lightblue 0px 50px,#ffffff00 50px 55px) 0 0/1px 55px ;
z-index: 1;
width: calc(55px * 9);
height: calc(55px * 9);
bottom: 0;
right: 0;
}
<div class="grid">
<div class="grid-item"><span>1</span></div>
<div class="grid-item"><span>2</span></div>
<div class="grid-item"><span>3</span></div>
<div class="grid-item"><span>4</span></div>
<div class="grid-item"><span>5</span></div>
<div class="grid-item"><span>6</span></div>
<div class="grid-item"><span>7</span></div>
<div class="grid-item"><span>8</span></div>
<div class="grid-item"><span>9</span></div>
<div class="grid-item"><span>10</span></div>
<div class="grid-item"><span>11</span></div>
<div class="grid-item"><span>12</span></div>
<div class="grid-item"><span>13</span></div>
<div class="grid-item"><span>14</span></div>
<div class="grid-item"><span>15</span></div>
<div class="grid-item"><span>16</span></div>
<div class="grid-item"><span>17</span></div>
<div class="grid-item"><span>18</span></div>
<div class="grid-item"><span>19</span></div>
<div class="grid-item"><span>20</span></div>
<div class="grid-item"><span>21</span></div>
<div class="grid-item"><span>22</span></div>
<div class="grid-item"><span>23</span></div>
<div class="grid-item"><span>24</span></div>
<div class="grid-item"><span>25</span></div>
</div>

Here is pure CSS solution with flexbox but too complex.
.grid {
display: flex;
flex-wrap: wrap;
flex-flow: wrap-reverse;
direction: rtl;
width: calc(50px*5 + 5px*4);
}
.grid-item {
width: 50px;
height: 50px;
display: flex;
justify-content: center;
align-items: center;
background: lightgray;
margin-bottom: 5px;
}
.grid-item:not(:nth-child(5n + 1)) {
margin-right: 5px;
}
.grid-item:nth-child(5n - 4):hover,
.grid-item:nth-child(5n - 4):hover~.grid-item,
.grid-item:nth-child(5n - 3):hover,
.grid-item:nth-child(5n - 3):hover~.grid-item:not(:nth-child(5n + 1)),
.grid-item:nth-child(5n - 2):hover,
.grid-item:nth-child(5n - 2):hover~.grid-item:not(:nth-child(5n + 1)):not(:nth-child(5n + 2)),
.grid-item:nth-child(5n - 1):hover,
.grid-item:nth-child(5n - 1):hover~.grid-item:not(:nth-child(5n + 1)):not(:nth-child(5n + 2)):not(:nth-child(5n + 3)),
.grid-item:nth-child(5n):hover,
.grid-item:nth-child(5n):hover~.grid-item:not(:nth-child(5n + 1)):not(:nth-child(5n + 2)):not(:nth-child(5n + 3)):not(:nth-child(5n + 4))
{
background: lightblue;
}
<div class="grid">
<div class="grid-item">25</div>
<div class="grid-item">24</div>
<div class="grid-item">23</div>
<div class="grid-item">22</div>
<div class="grid-item">21</div>
<div class="grid-item">20</div>
<div class="grid-item">19</div>
<div class="grid-item">18</div>
<div class="grid-item">17</div>
<div class="grid-item">16</div>
<div class="grid-item">15</div>
<div class="grid-item">14</div>
<div class="grid-item">13</div>
<div class="grid-item">12</div>
<div class="grid-item">11</div>
<div class="grid-item">10</div>
<div class="grid-item">9</div>
<div class="grid-item">8</div>
<div class="grid-item">7</div>
<div class="grid-item">6</div>
<div class="grid-item">5</div>
<div class="grid-item">4</div>
<div class="grid-item">3</div>
<div class="grid-item">2</div>
<div class="grid-item">1</div>
</div>

I think it very hard to do this with pure CSS, especially if you plan to expand this grid. However it can be done with javascript
document.querySelector('.grid').addEventListener("mouseover", function (event) {
Array.from(this.querySelectorAll('.grid-item')).forEach(node => {
var nodePosition = node.getBoundingClientRect();
if (nodePosition.x <= event.clientX && nodePosition.y <= event.clientY) {
node.classList.add('grid-item-blue')
}
else {
node.classList.remove('grid-item-blue')
}
})
});
.grid {
display: grid;
grid-template-columns: repeat(5, 50px);
grid-template-rows: repeat(5, 50px);
gap: 5px;
}
.grid-item {
display: flex;
justify-content: center;
align-items: center;
background: lightgray;
}
.grid-item-blue {
background: lightblue;
}
<!DOCTYPE html>
<html lang="en">
<head>
</head>
<body>
<div class="grid">
<div class="grid-item">1</div>
<div class="grid-item">2</div>
<div class="grid-item">3</div>
<div class="grid-item">4</div>
<div class="grid-item">5</div>
<div class="grid-item">6</div>
<div class="grid-item">7</div>
<div class="grid-item">8</div>
<div class="grid-item">9</div>
<div class="grid-item">10</div>
<div class="grid-item">11</div>
<div class="grid-item">12</div>
<div class="grid-item">13</div>
<div class="grid-item">14</div>
<div class="grid-item">15</div>
<div class="grid-item">16</div>
<div class="grid-item">17</div>
<div class="grid-item">18</div>
<div class="grid-item">19</div>
<div class="grid-item">20</div>
<div class="grid-item">21</div>
<div class="grid-item">22</div>
<div class="grid-item">23</div>
<div class="grid-item">24</div>
<div class="grid-item">25</div>
</div>
</body>
You can also use debouncing to reduce the number of times the mouseover callback function is triggered.

Add class to div on scroll up and down

As you can see I have a number of dots lined vertically! On scrolling down it works, as one scrolls the next dot gets a class thats chnages the style of the ball, I want the exact same to happen when i scroll up but it is not working! Please any input is appreciated!
Here is a code pen for your reference!
below the html, css and javascript:
var activeMilestone = function() {
var milestoneBalls = $('.dot');
milestoneBalls[0].classList.add("active");
window.onscroll = function() {
milestoneBalls.each(function(i, v) {
var thisBall = $(this);
var nextBall = milestoneBalls[i + 1];
var prevBall = milestoneBalls[i - 1];
var thisPositionTop = thisBall.offset().top + ($(this).parent().height() / 3);
var winScroll = window.scrollY;
if (thisPositionTop <= winScroll) {
nextBall.classList.add("active");
thisBall.addClass("inactive");
}
if (thisPositionTop >= winScroll) {
//this.classList.add("inactive_ball");
}
});
}
}
$(document).ready(activeMilestone);
.wrapper {
height: 1000px;
background-color: wheat;
}
.info_wrapper {
margin-top: 70px;
}
.container {
height: 50%;
display: flex;
flex-direction: column;
justify-content: space-between;
align-items: center;
}
.dot {
width: 30px;
height: 30px;
border-radius: 20px;
background-color: maroon;
border: solid 4px green;
}
.active {
border: solid 4px yellow;
background-color: red;
}
.inactive {
background-color: maroon;
border: solid 4px green;
}
.text {}
.header {
width: 100%;
height: 50px;
background-color: lightblue;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="wrapper">
<div class="header"></div>
<div class="container">
<div class="info_wrapper">
<div class="text"></div>
<div class="dot "></div>
</div>
<div class="info_wrapper">
<div class="text"></div>
<div class="dot "></div>
</div>
<div class="info_wrapper">
<div class="text"></div>
<div class="dot "></div>
</div>
<div class="info_wrapper">
<div class="text"></div>
<div class="dot"></div>
</div>
<div class="info_wrapper">
<div class="text"></div>
<div class="dot"></div>
</div>
<div class="info_wrapper">
<div class="text"></div>
<div class="dot"></div>
</div>
<div class="info_wrapper">
<div class="text"></div>
<div class="dot"></div>
</div>
<div class="info_wrapper">
<div class="text"></div>
<div class="dot"></div>
</div>
</div>
</div>

So this logic performs the same that you were doing already. With the added logic of, if the element should not advance, and we are not the first element, we check to see if the previous ball should be active. And if so, we make it active.
var activeMilestone = function() {
var milestoneBalls = $('.dot');
milestoneBalls.eq(0).addClass('active');
window.addEventListener('scroll', function() {
var activeBall = milestoneBalls.filter('.active');
var activeBallIndex = milestoneBalls.index( activeBall );
var activeBallPositionTop = activeBall.offset().top + (activeBall.parent().height() / 3);
if (activeBallPositionTop <= window.scrollY) {
activeBall.removeClass('active');
milestoneBalls.eq( activeBallIndex + 1).addClass('active');
} else if ( activeBallIndex ) {
var previousBall = milestoneBalls.eq( activeBallIndex - 1 );
var previousBallPositionTop = previousBall.offset().top + (previousBall.parent().height() / 3);
if (previousBallPositionTop > window.scrollY) {
activeBall.removeClass('active');
previousBall.addClass('active');
}
}
});
}
$(document).ready(activeMilestone);
.wrapper {
height: 1000px;
background-color: wheat;
}
.info_wrapper {
margin-top: 70px;
}
.container {
height: 50%;
display: flex;
flex-direction: column;
justify-content: space-between;
align-items: center;
}
.dot {
width: 30px;
height: 30px;
border-radius: 20px;
background-color: maroon;
border: solid 4px green;
}
.active {
border: solid 4px yellow;
background-color: red;
}
.inactive {
background-color: maroon;
border: solid 4px green;
}
.text {}
.header {
width: 100%;
height: 50px;
background-color: lightblue;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="wrapper">
<div class="header"></div>
<div class="container">
<div class="info_wrapper">
<div class="text"></div>
<div class="dot "></div>
</div>
<div class="info_wrapper">
<div class="text"></div>
<div class="dot "></div>
</div>
<div class="info_wrapper">
<div class="text"></div>
<div class="dot "></div>
</div>
<div class="info_wrapper">
<div class="text"></div>
<div class="dot"></div>
</div>
<div class="info_wrapper">
<div class="text"></div>
<div class="dot"></div>
</div>
<div class="info_wrapper">
<div class="text"></div>
<div class="dot"></div>
</div>
<div class="info_wrapper">
<div class="text"></div>
<div class="dot"></div>
</div>
<div class="info_wrapper">
<div class="text"></div>
<div class="dot"></div>
</div>
</div>
</div>

You can use on wheel from jQuery.
$(window).on('wheel',function(e) {
var mov = e.originalEvent.deltaY;
if(mov > 0) {
alert("up");
}else {
alert("down");
}
});
This will sort out your problem regarding detection of scrolling direction.

CSS columns separating divs

I am building platform with template like a https://pinterest.com and
I have html structure like this:
<div class="main">
<div class="content">
<div class="content_publisher">
</div>
<div class="content-text">
</div>
</div>
</div>
And i have style.css like this:
body {
width:1358px;
}
.main {
column-width:339.33px;
column-gap: 0;
column-count:4;
position:relative;
top:50px;
width:100%;
}
.content {
display:block;
margin-bottom:10px;
width:337px;
-webkit-box-shadow:inset 0px 0px 10px;
}
My page is devided to 4 columns... Look at the image you will understand what i want exaclty..
https://i.stack.imgur.com/fPfDp.png As you can see at the end of the column, The column is separating divs inside in content div..

Use display: inline-block on .content.
body {
width: 1358px;
}
.main {
column-width: 339.33px;
column-gap: 0;
column-count: 4;
position: relative;
top: 50px;
width: 100%;
}
.content {
display: inline-block;
margin-bottom: 10px;
width: 337px;
-webkit-box-shadow: inset 0px 0px 10px;
height: 200px;
background: #eee;
}
.content:nth-child(odd) {
height: 150px;
}
<div class="main">
<div class="content">
</div>
<div class="content">
</div>
<div class="content">
</div>
<div class="content">
</div>
<div class="content">
</div>
<div class="content">
</div>
<div class="content">
</div>
<div class="content">
</div>
<div class="content">
</div>
<div class="content">
</div>
<div class="content">
</div>
<div class="content">
</div>
<div class="content">
</div>
<div class="content">
</div>
<div class="content">
</div>
<div class="content">
</div>
<div class="content">
</div>
<div class="content">
</div>
<div class="content">
</div>
<div class="content">
</div>
<div class="content">
</div>
<div class="content">
</div>
<div class="content">
</div>
<div class="content">
</div>
<div class="content">
</div>
<div class="content">
</div>
</div>

My JS is not working with my html/css. Not sure why. (Console error 'ReferenceError: $ is not defined')

I am trying to create a content slider, and am having difficulties with it functioning appropriately. Specifically when testing locally the aspect that is not working is: (When you click the arrows left or right the current-slide fades out and fades back in but the slide content does not switch to the next block of content.)
Here is my HTML:
<!DOCTYPE html>
<html>
<head>
<html lang="en-US">
<meta charset="UTF-8">
<title>PLACEHOLDER</title>
<meta name"keywords" content="PLACEHOLDER" />
<meta name"description" content="PLACEHOLDER" />
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.6.4/jquery.min.js"></script>
<script src="code.js"></script>
<link type="text/css" rel="stylesheet" href="style2.css" />
</head>
<body>
<div class="slider">
<div class="slide active-slide">
<div class="container">
<div class="row">
<div class="slide-copy col-xs-5">
<h1 id="welcome">FIRST SLIDE HEADER</h1>
<div id="img1">
<img src="######.png" width="450" height="250" />
</div>
<div id="intro">
<p>FIRST SLIDE CONTENT</p </div>
</div>
</div>
</div>
<div class="slide slide-feature">
<div class="container">
<div class="row">
<div class="col-xs-12">
<h1>Slide2</h1>
<p>Slide 2 stuff.</p>
</div>
</div>
</div>
</div>
<div class="slide">
<div class="container">
<div class="row">
<div class="slide-copy col-xs-5">
<h1>Slide 3</h1>
<h2>Slide3</h2>
<p>Slide3 content</p>
</div>
</div>
</div>
</div>
<div class="slide">
<div class="container">
<div class="row">
<div class="slide-copy col-xs-5">
<h1>Slide 4</h1>
<p>slide 4 content</p>
</div>
</div>
</div>
</div>
</div>
<div class="slider-nav">
<a href="#" class="arrow-prev">
<img src="ARROW LEFT IMAGE">
</a>
<ul class="slider-dots">
<li class="dot active-dot">•</li>
<li class="dot">•</li>
<li class="dot">•</li>
<li class="dot">•</li>
</ul>
<a href="#" class="arrow-next">
<img src="ARROW RIGHT IMAGE">
</a>
</div>
Here is my JS:
var main = function () {
$('.arrow-next').click(function () {
var currentSlide = $('.active-slide');
var nextSlide = currentSlide.next();
var currentDot = $('.active-dot');
var nextDot = currentDot.next()
if (nextSlide.length === 0) {
nextSlide = $('.slide').first();
nextDot = $('.dot').first();
}
currentSlide.fadeOut(600).removeClass('active-slide');
nextSlide.fadeIn(600).addClass('active-slide');
currentDot.removeClass('active-dot');
nextDot.addClass('active-dot');
});
$('.arrow-prev').click(function()
{
var currentSlide = $('.active-slide');
var prevSlide = currentSlide.prev();
var currentDot = $('.active-dot');
var prevDot = currentDot.prev()
if(prevSlide.length == 0)
{
prevSlide = $('.slide').last();
prevDot = $('.dot').last();
}
currentSlide.fadeOut(600).removeClass('active-slide');
prevSlide.fadeIn(600).addClass('active-slide');
currentDot.removeClass('active-dot');
prevDot.addClass('active-dot');
});
};
$(document).ready(main);
HERE IS MY CSS(Just to tie it all together):
.slider {
position: relative;
width: 50%;
height: 470px;
margin-left: 25%;
border-bottom: 1px solid #ddd;
margin-top: -8%;
}
.slide {
background: transparent url('http://s3.amazonaws.com/codecademy-content/courses/ltp2/img/flipboard/feature-gradient-transparent.png') center center no-repeat;
background-size: cover;
display: none;
position: absolute;
top: 0;
left: 0;
width: 100%;
height: 100%;
}
.active-slide {
display: block;
}
.slide-copy h1 {
color: #363636;
font-family: 'Oswald', sans-serif;
font-weight: 400;
font-size: 40px;
margin-top: 105px;
margin-bottom: 0px;
}
.slide-copy h2 {
color: #b7b7b7;
font-family: 'Oswald', sans-serif;
font-weight: 400;
font-size: 40px;
margin: 5px;
}
.slide-copy p {
color: #959595;
font-family: Georgia, "Times New Roman", serif;
font-size: 1.15em;
line-height: 1.75em;
margin-bottom: 15px;
margin-top: 16px;
}
.slide-img {
text-align: right;
}
/* Slide feature */
.slide-feature {
text-align: center;
background-image: url('http://s3.amazonaws.com/codecademy-content/courses/ltp2/img/flipboard/ac.png');
height: 470px;
}
.slide-feature img {
margin-top: 112px;
margin-bottom: 28px;
}
.slide-feature a {
display: block;
color: #6fc5e0;
font-family: "HelveticaNeueMdCn", Helvetica, sans-serif;
font-family: 'Oswald', sans-serif;
font-weight: 400;
font-size: 20px;
}
.slider-nav {
text-align: center;
margin-top: 20px;
margin-top: 30%;
}
.arrow-prev {
margin-right: 45px;
display: inline-block;
vertical-align: top;
margin-top: 9px;
}
.arrow-next {
margin-left: 45px;
display: inline-block;
vertical-align: top;
margin-top: 9px;
}
.slider-dots {
list-style: none;
display: inline-block;
padding-left: 0;
margin-bottom: 0;
}
.slider-dots li {
color: #bbbcbc;
display: inline;
font-size: 30px;
margin-right: 5px;
}
.slider-dots li.active-dot {
color: #363636;
}
NOTE: I only put the sections of html/js/css that matter for this case. And I used placeholders for some text and images. On my local machine those placeholders are replaced with correct content.

if you look at the HTML closely, you'll see that the slider div's are not positioned properly. all the other div's with the class '.slide' are enclosed inside <div class="slide active-slide"> whereas they should be independent of each other.
the javascript code is not able to find the next() slide since they're all contained in one single parent which is the 'active-slide'
you need to update your HTML to the following
<div class="slider">
<div class="slide active-slide">
<div class="container">
<div class="row">
<div class="slide-copy col-xs-5">
<h1 id="welcome">FIRST SLIDE HEADER</h1>
<div id="img1">
<img src="######.png" width="450" height="250" />
</div>
<div id="intro">
<p>FIRST SLIDE CONTENT</p </div>
</div>
</div>
</div>
</div>
</div>
<div class="slide slide-feature">
<div class="container">
<div class="row">
<div class="col-xs-12">
<h1>Slide2</h1>
<p>Slide 2 stuff.</p>
</div>
</div>
</div>
</div>
<div class="slide">
<div class="container">
<div class="row">
<div class="slide-copy col-xs-5">
<h1>Slide 3</h1>
<h2>Slide3</h2>
<p>Slide3 content</p>
</div>
</div>
</div>
</div>
<div class="slide">
<div class="container">
<div class="row">
<div class="slide-copy col-xs-5">
<h1>Slide 4</h1>
<p>slide 4 content</p>
</div>
</div>
</div>
</div>
</div>
<div class="slider-nav">
<a href="#" class="arrow-prev">
<img src="ARROW LEFT IMAGE">
</a>
<ul class="slider-dots">
<li class="dot active-dot">•</li>
<li class="dot">•</li>
<li class="dot">•</li>
<li class="dot">•</li>
</ul>
<a href="#" class="arrow-next">
<img src="ARROW RIGHT IMAGE">
</a>
</div>
here's a working JSFIDDLE for the same. hope this helps

You just need to include the jQuery library from here: http://jquery.com/download/

You will get this error if you haven't included jquery file or you are getting conflicts in jquery.
ReferenceError: $ is not defined
Add following in Head section of your code:
<script src="//code.jquery.com/jquery-1.11.3.min.js"></script>

Auto-scroll to a div when clicking on another div

When I click on one of the smaller divs on the left (inside of the div with the class "smallitems", I want for the div on the right (with the class "items") to auto-scroll to the appropriate larger div.
HTML:
<div class="smallitems">
<div class="col">1</div>
<div class="col"> 2 </div>
<div class="col"> 3</div>
<div class="col">4</div>
<div class="col"> 5 </div>
<div class="col">6 </div>
<div class="col"> 7</div>
<div class="col">8</div>
</div>
<div class="items">
<div class="item">1</div>
<div class="item">2</div>
<div class="item">3</div>
<div class="item">4</div>
<div class="item">5</div>
<div class="item">6</div>
<div class="item">7</div>
<div class="item">5</div>
</div>
JavaScript (with JQuery):
$('.smallitems .col').on("click", function(){
//how use scroll items show
});
Example:
This is before I click on a div in the left div ("smallitems").
I've now clicked on the number 5 (<div class="col">5</div>) in the left div. As you can see the right div has scrolled to the 5th div (<div class="item">5</div>).
Similar to the above, I've clicked on the number 4, and subsequently have had the right div auto-scroll to the 4th div.
see jfiddle http://jsfiddle.net/h7bLK/

This can be done with anchors. If you replace your div.cols with anchor tags and add an ID to your div.items like this:
<div class="smallitems">
<a class="col" href="#item1">1</a>
<a class="col" href="#item2">2</a>
. . .
</div>
<div class="items">
<div class="item" id="item1">1</div>
<div class="item" id="item2">2</div>
. . .
</div>
Fiddle link
BONUS: You'll be able to link externally to the correct item.
CONS: If the content is smaller than the frame it is rendered in, the whole frame will scroll.

According to requirement, no-need to use javascript or jquery. Its done only using css.
<div class="main-container">
<div class="smallitems">
<div class="col">1</div>
<div class="col"> 2 </div>
<div class="col last-child">3</div>
<div class="col">4</div>
<div class="col">5 </div>
<div class="col last-child">6 </div>
<div class="col"> 7</div>
<div class="col">8</div>
</div>
<div class="items">
<div class="scroll">
<div class="item" id="one">1</div>
<div class="item" id="two">2</div>
<div class="item" id="three">3</div>
<div class="item" id="four">4</div>
<div class="item" id="five">5</div>
<div class="item" id="six">6</div>
<div class="item" id="seven">7</div>
<div class="item" id="eight">8</div>
</div>
</div>
</div>
**Css** :
.main-container{
margin: 20px auto;
width:960px;
overflow: hidden;
border: 1px solid #bababa;
padding: 5px;
}
.smallitems{
overflow: hidden;
float: left;
width:330px;
border: 1px solid #bababa;
display: table;
padding: 10px;
}
.col a{
display: block;
padding: 41px 0;
text-decoration: none;
}
.col{
float:left;
display: table-cell;
vertical-align: middle;
text-align: center;
font-size: 14px;
font-weight: 700;
cursor: pointer;
border: 1px solid #bababa;
height: 100px;
width: 100px;
margin: 0 10px 10px 0;
}
.items{
float: right;
width:580px;
border: 1px solid #bababa;
overflow-y: hidden;
white-space: nowrap;
padding: 10px;
}
.col:nth-child(3),.last-child{
margin-right: 0;
}
.item{
display: inline-block;
text-align: center;
position:relative;
font-size: 14px;
font-weight: 700;
border: 1px solid #bababa;
height: 440px;
width: 180px;
margin: 0 10px 10px 0;
}

$('.smallitems .col').on("click", function(){
var index = $(this).index();
var items = $('.items');
var item = items.children().eq(index);
items.scrollLeft((item.width() - 50) * index);
});
When you add a new div to the items play around with the value of 50.

<div class="container">
<div class="smallitems">
<div class="col">1</div>
<div class="col"> 2 </div>
<div class="col"> 3</div>
<div class="col">4</div>
<div class="col"> 5 </div>
<div class="col">6 </div>
<div class="col"> 7</div>
<div class="col">8</div>
</div>
<div class="items" id="maindiv"> // set id
<div class="item">1</div>
<div class="item">2</div>
<div class="item">3</div>
<div class="item">4</div>
<div class="item">5</div>
<div class="item">6</div>
<div class="item">7</div>
<div class="item">5</div>
</div>
</div>
$('.smallitems').on("click", function(e){
// get click element text and calculate scrollLeft
var scrollLeft = (parseInt($(e.target).text())-1) * 200;
// use jquery animation function
$('#maindiv').animate({scrollLeft :scrollLeft},1100)
});