timeline.css

@import "https://fonts.googleapis.com/css?family=Dosis:300,400,500,600,700";
#timeline .timeline-item:after, #timeline .timeline-item:before {
  content: '';
  display: block;
  width: 100%;
  clear: both;
}
*, *:before, *:after {
  box-sizing: border-box;
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
}
body, html {
  height: 100%;
}
body {
  background: #f9f9f9;
  background-size: cover;
  margin: 0;
  padding: 0;
  font-family: helvetica, arial, tahoma, verdana;
  line-height: 20px;
  font-size: 14px;
  color: #726f77;
}
img {
  max-width: 100%;
}
a {
  text-decoration: none;
}
.container {
  max-width: 1100px;
  margin: 0 auto;
}
h1, h2, h3, h4 {
  font-family: "Dosis", arial, tahoma, verdana;
  font-weight: 500;
}
.project-name {
  text-align: center;
  padding: 10px 0;
}
#timeline {
  width: 100%;
  margin: 30px auto;
  position: relative;
  padding: 0 10px;
  -webkit-transition: all 0.4s ease;
  -moz-transition: all 0.4s ease;
  -ms-transition: all 0.4s ease;
  transition: all 0.4s ease;
}
#timeline:before {
  content: "";
  width: 3px;
  height: 100%;
  background: #ee4d4d;
  left: 50%;
  top: 0;
  position: absolute;
}
#timeline:after {
  content: "";
  clear: both;
  display: table;
  width: 100%;
}
#timeline .timeline-item {
  margin-bottom: 50px;
  position: relative;
}
#timeline .timeline-item .timeline-icon {
  background: #ee4d4d;
  width: 50px;
  height: 50px;
  position: absolute;
  top: 0;
  left: 50%;
  overflow: hidden;
  margin-left: -23px;
  -webkit-border-radius: 50%;
  -moz-border-radius: 50%;
  -ms-border-radius: 50%;
  border-radius: 50%;
}
#timeline .timeline-item .timeline-icon svg {
  position: relative;
  top: 14px;
  left: 14px;
}
#timeline .timeline-item .timeline-content {
  width: 45%;
  background: #fff;
  padding: 20px;
  -webkit-border-radius: 5px;
  -moz-border-radius: 5px;
  -ms-border-radius: 5px;
  border-radius: 5px;
  -webkit-transition: all 0.3s ease;
  -moz-transition: all 0.3s ease;
  -ms-transition: all 0.3s ease;
  transition: all 0.3s ease;
}
#timeline .timeline-item .timeline-content h2 {
  padding: 15px;
  background: #ee4d4d;
  color: #fff;
  margin: -20px -20px 0 -20px;
  font-weight: 300;
  -webkit-border-radius: 3px 3px 0 0;
  -moz-border-radius: 3px 3px 0 0;
  -ms-border-radius: 3px 3px 0 0;
  border-radius: 3px 3px 0 0;
}
#timeline .timeline-item .timeline-content:before {
  content: '';
  position: absolute;
  left: 45%;
  top: 20px;
  width: 0;
  height: 0;
  border-top: 7px solid transparent;
  border-bottom: 7px solid transparent;
  border-left: 7px solid #ee4d4d;
}
#timeline .timeline-item .timeline-content.right {
  float: right;
}
#timeline .timeline-item .timeline-content.right:before {
  content: '';
  right: 45%;
  left: inherit;
  border-left: 0;
  border-right: 7px solid #ee4d4d;
}
.btn {
  padding: 5px 15px;
  text-decoration: none;
  background: transparent;
  border: 2px solid #f27c7c;
  color: #f27c7c;
  display: inline-block;
  position: relative;
  text-transform: uppercase;
  font-size: 12px;
  -webkit-border-radius: 5px;
  -moz-border-radius: 5px;
  -ms-border-radius: 5px;
  border-radius: 5px;
  -webkit-transition: background 0.3s ease;
  -moz-transition: background 0.3s ease;
  -ms-transition: background 0.3s ease;
  transition: background 0.3s ease;
  -webkit-box-shadow: 2px 2px 0 #f27c7c;
  -moz-box-shadow: 2px 2px 0 #f27c7c;
  -ms-box-shadow: 2px 2px 0 #f27c7c;
  box-shadow: 2px 2px 0 #f27c7c;
}
.btn:hover {
  box-shadow: none;
  top: 2px;
  left: 2px;
  -webkit-box-shadow: 2px 2px 0 transparent;
  -moz-box-shadow: 2px 2px 0 transparent;
  -ms-box-shadow: 2px 2px 0 transparent;
  box-shadow: 2px 2px 0 transparent;
}
@media screen and (max-width: 768px) {
  #timeline {
    margin: 30px;
    padding: 0px;
    width: 90%;
  }
  #timeline:before {
    left: 0;
  }
  #timeline .timeline-item .timeline-content {
    width: 90%;
    float: right;
  }
  #timeline .timeline-item .timeline-content:before, #timeline .timeline-item .timeline-content.right:before {
    left: 10%;
    margin-left: -6px;
    border-left: 0;
    border-right: 7px solid #ee4d4d;
  }
  #timeline .timeline-item .timeline-icon {
    left: 0;
  }
}

timeline.html

@import "https://fonts.googleapis.com/css?family=Dosis:300,400,500,600,700";

// Variables
$bg-body: #f9f9f9;

$red: #ee4d4d;
$blue: #2b2e48;
$primary-color: $red;
$secondary-color: $blue;


// Typography
$base-font: helvetica, arial, tahoma, verdana;
$base-font-title: "Dosis", arial, tahoma, verdana;

$base-font-color: #726f77;

// Timeline
$timeline-color: $primary-color;


// Mixins and Placeholders
%clearfix {
	&:after, &:before {
		content: '';
		display: block;
		width: 100%;
		clear: both;
	}
}

@mixin prefix($prop, $val) {
	@each $prefix in '-webkit-', '-moz-', '-ms-', '' {
		#{$prefix}#{$prop}: $val;
	}
}
*, *:before, *:after {
	box-sizing: border-box;
	-webkit-box-sizing: border-box;
	-moz-box-sizing: border-box;
}

body, html {
	height: 100%;
}
body {
	background: $bg-body;
	background-size: cover;
	margin: 0;
	padding: 0;
	font-family: $base-font;
	line-height: 20px;
	font-size: 14px;
	color: $base-font-color;
}

img {max-width: 100%;}

a {
	text-decoration: none;
}

.container {
	max-width: 1100px;
	margin: 0 auto;
}

h1, h2, h3, h4 {
  font:{
		family: $base-font-title;
		weight: 500;
	}
}

.project-name {
  text-align: center;
  padding: 10px 0;
}

// Header
header {	
	background: $secondary-color;
	padding: 10px;
	@include prefix(box-shadow, 0 3px 3px rgba(0,0,0,0.05)); 
	@extend %clearfix;

	.logo {
		color: $primary-color;
		float: left;
		font:{
			family: $base-font-title;
			size: 22px;
			weight: 500;
		}
		
		> span {
			color: lighten($primary-color, 20%);
			font-weight: 300;
		}
	}

	.social {
		float: right;
		.btn {
			font-family: "Dosis";
			font-size: 14px;
			margin: 10px 5px;
		}
	}
}


// Timeline
#timeline {
	width: 100%;
  margin: 30px auto;
	position: relative;
  padding: 0 10px;
	@include prefix(transition, all .4s ease);

	&:before {
		content:"";
		width: 3px;
		height: 100%;
		background: $timeline-color;
		left: 50%;
		top: 0;
		position: absolute;
	}

	&:after {
		content: "";
		clear: both;
		display: table;
		width: 100%;
	}
	
	.timeline-item {
		margin-bottom: 50px;
		position: relative;
		@extend %clearfix;

		.timeline-icon {
			background: $timeline-color;
			width: 50px;
			height: 50px;
			position: absolute;
			top: 0;
			left: 50%;
			overflow: hidden;
			margin-left: -23px;
			@include prefix(border-radius, 50%);

			svg {
				position: relative;
				top: 14px;
				left: 14px;
			}
		}

		.timeline-content {
			width: 45%;
			background: #fff;
			padding: 20px;
			@include prefix(box-shadow, 0 3px 0 rgba(0,0,0,0.1));
			@include prefix(border-radius, 5px);
			@include prefix(transition, all .3s ease);

			h2 {
				padding: 15px;
				background: $timeline-color;
				color: #fff;
				margin: -20px -20px 0 -20px;
				font-weight: 300;
				@include prefix(border-radius, 3px 3px 0 0);
			}

			&:before {
				content: '';
				position: absolute;
				left: 45%;
				top: 20px;
				width: 0; 
				height: 0; 
				border-top: 7px solid transparent;
				border-bottom: 7px solid transparent; 
				border-left:7px solid $timeline-color; 
			}

			&.right {
				float: right;

				&:before {
					content: '';
					right: 45%;
					left: inherit;
					border-left: 0;
					border-right: 7px solid $timeline-color;
				}
			}
		}
	}
}

// Buttons
.btn {
	padding: 5px 15px;
	text-decoration: none;
	background: transparent;
	border: 2px solid lighten($primary-color, 10%);
	color: lighten($primary-color, 10%);
	display: inline-block;
	position: relative;
	text-transform: uppercase;
	font-size: 12px;
	@include prefix(border-radius, 5px);
	@include prefix(transition, background .3s ease);
	@include prefix(box-shadow, 2px 2px 0 lighten($primary-color, 10%));

	&:hover {
		box-shadow: none ;
		top: 2px;
		left: 2px;
		@include prefix(box-shadow, 2px 2px 0 transparent);
	}
}

@media screen and (max-width: 768px) {
	#timeline {
		margin: 30px;
		padding: 0px;
    width: 90%;
		&:before {
			left: 0;
		}
		
		.timeline-item {
			.timeline-content {
				width: 90%;
				float: right;
				
				&:before, &.right:before {
					left: 10%;
					margin-left: -6px;
					border-left: 0;
					border-right: 7px solid $timeline-color;
				}
			}

			.timeline-icon {
				left: 0;
			}
		}
	}
}