.mybox {
    border-radius: 8px;
    padding: 16px;
    margin: 1.5em 0;
    border: 2px solid #ddd;
    background: #fff;
}

.mybox-title {
    font-size: 1.1em;
    font-weight: bold;
    margin-bottom: 0.6em;
}

/* カラー */
.mybox-blue {
    border-color: #2589d0;
    background: #f1f8ff;
}

.mybox-gray {
    border-color: #9e9e9e;
    background: #fafafa;
}

.mybox-green {
    border-color: #3fa66b;
    background: #f2fff8;
}

.mybox-yellow {
    border-color: #e0a800;
    background: #fffdf1;
}