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.timeline {
    position: relative;
    padding: 0;
    list-style: none;

    // Timeline Middle Line
    &:before {
        top: 0;
        bottom: 0;
        position: absolute;
        content: "";
        width: 2px;
        background-color: #f1f1f1;
        left: 40px;
        margin-left: -1.5px;
    }

    // Timeline Block
    > li {
        margin-bottom: 50px;
        position: relative;
        min-height: 50px;

        &:before,
        &:after {
            content: "";
            display: table;
        }

        &:after {
            clear: both;
        }

        // Timeline Panel
        .timeline-panel {
            width: 100%;
            float: right;
            padding: 0 20px 0 100px;
            position: relative;
            text-align: left;

            &:before {
                border-left-width: 0;
                border-right-width: 15px;
                left: -15px;
                right: auto;
            }

            &:after {
                border-left-width: 0;
                border-right-width: 14px;
                left: -14px;
                right: auto;
            }
        }

        // Timeline Image
        .timeline-image {
            left: 0;
            margin-left: 0;
            .size(80px);
            position: absolute;
            z-index: 100;
            background-color: @brand-gold;
            color: #fff;
            border-radius: 100%;
            border: 7px solid #f1f1f1;
            text-align: center;

            h4 {
                font-size: 10px;
                margin-top: 12px;
                line-height: 14px;
            }
        }

        // Timeline Inverted Block
        &.timeline-inverned > .timeline-panel {
            float: right;
            text-align: left;
            padding: 0 20px 0 100px;

            &:before {
                border-left-width: 0;
                border-right-width: 15px;
                left: -15px;
                right: auto;
            }

            &:after {
                border-left-width: 0;
                border-right-width: 14px;
                left: -14px;
                right: auto;
            }
        }

        &:last-child {
            margin-bottom: 0;
        }
    }

    // Timeline Panel Heading
    .timeline-heading {
        h4 {
            .heading-font;
            margin-top: 0;
        }
    }

    // Timeline Heading Body
    .timeline-body {
        > p,
        > ul {
            margin-bottom: 0;
        }
    }
    
    @media @min-tablet {
        // Timeline Middle Line
        &:before {
            left: 50%;
        }

        // Timeline Block
        > li {
            margin-bottom: 100px;
            min-height: 100px;

            .timeline-panel {
                width: 41%;
                float: left;
                padding: 0 20px 20px 30px;
                text-align: right;
            }

            .timeline-image {
                .size(100px);
                left: 50%;
                margin-left: -50px;

                h4 {
                    font-size: 13px;
                    margin-top: 16px;
                    line-height: 18px;
                }
            }

            &.timeline-inverted > .timeline-panel {
                float: right;
                text-align: left;
                padding: 0 30px 20px 20px;
            }
        }
    }

    @media @min-desktop {
        > li {
            min-height: 150px;

            .timeline-panel {
                padding: 0 20px 20px;
            }

            .timeline-image {
                .size(150px);
                margin-left: -75px;

                h4 {
                    font-size: 18px;
                    margin-top: 30px;
                    line-height: 26px;
                }
            }
        }
    }
    
    @media @min-desktop-lg {
        > li {
            min-height: 170px;
            .timeline-panel {
                padding: 0 20px 20px 100px;
            }
            .timeline-image {
                width: 170px;
                height: 170px;
                margin-left: -85px;
                h4 {
                    margin-top: 40px;
                }
            }
            &.timeline-inverted > .timeline-panel {
                padding: 0 100px 20px 20px;
            }
        }
    }
}

<div class="container">
  <div class="row">
    <div class="col-lg-12">
        <ul class="timeline">
            
            <li>
                <div class="timeline-image">
                    <img src="img/about/1.jpg" alt="" class="img-circle img-responsive">
                </div>
                <div class="timeline-panel">
                    <div class="timeline-heading">
                        <h4>2009-2011</h4>
                        <h4 class="subheading">Our Humble Beginnings</h4>
                    </div>
                    <div class="timeline-body">
                        <p class="text-muted">Lorem ipsum dolor sit amet, consectetur adipisicing elit. Sunt ut voluptatum eius sapiente, totam reiciendis temporibus qui quibusdam, recusandae sit vero unde, sed, incidunt et ea quo dolore laudantium consectetur!</p>
                    </div>
                </div>
            </li>
            
            <li>
                <div class="timeline-image">
                    <img src="img/about/1.jpg" alt="" class="img-circle img-responsive">
                </div>
                <div class="timeline-panel">
                    <div class="timeline-heading">
                        <h4>March 2011</h4>
                        <h4 class="subheading">An Agency is Born</h4>
                    </div>
                    <div class="timeline-body">
                        <p class="text-muted">Lorem ipsum dolor sit amet, consectetur adipisicing elit. Sunt ut voluptatum eius sapiente, totam reiciendis temporibus qui quibusdam, recusandae sit vero unde, sed, incidunt et ea quo dolore laudantium consectetur!</p>
                    </div>
                </div>
            </li>
            
            <li class="timeline-inverted">
                <div class="timeline-image">
                    <h4>Be Part <br>Of Out<br>Story!</h4>
                </div>
            </li>
            
        </ul>
        <!-- /.timeline -->
    </div>
    <!-- /.col-lg-12 -->
  </div>
  <!-- /.row -->
</div>