.calendar-container {
    width: 100%;
    overflow-x: auto;
    padding: 20px 0 20px 0;
    box-sizing: border-box;
    margin-bottom: 10px;
}

.ir-calendar {
    width: 100%;
    max-width: 1000px;
    min-width: 768px;
    margin: 0 auto;
    font-family: "Helvetica Neue", Arial, "Hiragino Kaku Gothic ProN", "Hiragino Sans", Meiryo, sans-serif;
    color: #333;
}

.quarters {
    display: flex;
    width: 100%;
}

.quarter {
    flex: 1;
    text-align: center;
    padding: 12px 0;
    color: #fff;
    font-weight: bold;
    font-size: 14px;
    letter-spacing: 1px;
}

.q-dark {
    background-color: #001c5b;
}

.q-light {
    background-color: #6b7dab;
}

.timeline-area {
    position: relative;
    padding-bottom: 90px;
}

.timeline-bg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    z-index: 0;
}

.bg-col {
    flex: 1;
    border-left: 2px dashed #dcdcdc;
}

.bg-col:last-child {
    border-right: 2px dashed #dcdcdc;
}

.horizontal-line {
    position: absolute;
    top: 55px;
    left: 0;
    width: 100%;
    height: 2px;
    background-color: #1b87ce;
    z-index: 1;
}

.timeline-content {
    display: flex;
    width: 100%;
    position: relative;
    z-index: 2;
}

.month {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    position: relative;
}

.month-label {
    margin-top: 15px;
    font-size: 15px;
    font-weight: bold;
    background-color: #fff;
    padding: 0 4px;
    position: relative;
    z-index: 3;
}

.node {
    width: 16px;
    height: 16px;
    background-color: #1b87ce;
    border-radius: 50%;
    position: absolute;
    top: 48px;
    z-index: 3;
}

.event {
    position: absolute;
    top: 80px;
    background-color: #1b87ce;
    color: #fff;
    padding: 10px 14px;
    border-radius: 4px;
    font-size: 13px;
    font-weight: bold;
    white-space: nowrap;
    left: 50%;
    transform: translateX(-50%);
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
    z-index: 4;
}

.event::before {
    content: "";
    position: absolute;
    top: -10px;
    left: 50%;
    transform: translateX(-50%);
    border-width: 0 8px 10px 8px;
    border-style: solid;
    border-color: transparent transparent #1b87ce transparent;
}

.event-shift-left-8 {
    transform: translateX(-75%);
}
.event-shift-left-8::before {
    left: 75%;
}

.event-shift-right-9 {
    transform: translateX(-25%);
}
.event-shift-right-9::before {
    left: 25%;
}

.event-shift-right-11 {
    transform: translateX(-20%);
}
.event-shift-right-11::before {
    left: 20%;
}