Tabs to make center aligned

This is the WordPress theme tab I am working on and I am trying to make he tabs center aligned. I tried to make various changes in the firebug but the alignment doesn’t set to center accurately cause when I change the width the alignment gets unaligned. Kindly let me know how can I make the tabs center aligned like following image which should work regardless whatever the width is:

/*Tab*/
.shortcode-tab-wrap .tabs {
    list-style: none;
    margin: 0;
}

.shortcode-tab .tabs li.tab {
    float: left;
    position: relative;
}

.shortcode-tab .tabs li.tab a {
    display: block;
    height: 45px;
    line-height: 45px;
    padding: 0 20px;
}

.shortcode-tab .tabs li.tab a .separate {
    position: absolute;
    bottom: -1px;
    left: 0;
    width: 100%;
    height: 1px;
    display: block;
}

.shortcode-tab .tabs-content {
    padding: 20px;
}

.shortcode-left-tab {
    position: relative;
}

.shortcode-left-tab .tabs {
    position: absolute;
    top: 0;
    left: 2px;
    width: 200px;
}

.shortcode-left-tab .tabs li.tab {
    position: relative;
}

.shortcode-left-tab .tabs li.tab a {
    display: block;
    height: 45px;
    line-height: 45px;
    padding: 0 20px;
}

.shortcode-left-tab .tabs li.tab a .separate {
    position: absolute;
    top: 0;
    right: -1px;
    width: 1px;
    height: 45px;
    display: block;
}

.shortcode-left-tab .tabs-content {
    margin-left: 202px;
    padding: 20px;
}