#color-div{
    width: 200px;
    height: 200px;
    border: 1px solid #ccc;
    margin: auto;
}
.btn {
    display: inline-block;
    margin-bottom: 0;
    font-weight: 400;
    text-align: center;
    white-space: nowrap;
    vertical-align: middle;
    -ms-touch-action: manipulation;
    touch-action: manipulation;
    cursor: pointer;
    background-image: none;
    border: 1px solid transparent;
    padding: 6px 12px;
    font-size: 14px;
    line-height: 1.42857143;
    border-radius: 4px;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
}
.btn-success {
    color: #fff;
    background-color: #5cb85c;
    border-color: #4cae4c;
}
.btn.disabled, .btn[disabled], fieldset[disabled] .btn {
    cursor: not-allowed;
    filter: alpha(opacity = 65);
    opacity: .65;
    -webkit-box-shadow: none;
    box-shadow: none;
}
.alert-warning {
    color: #8a6d3b;
    background-color: #fcf8e3;
    border-color: #faebcc;
}
.alert {
    padding: 15px;
    margin-top: 1rem;
    border: 1px solid transparent;
    border-radius: 4px;
}
#tool-result{
    background-color: #f6f7fa;
    border: 1px solid #d9deea;
    border-radius: 3px;
    padding: 8px 12px;
    font-size: 14px;
    line-height: 1.42857143;
    color: #627ec1;
    margin-top: 1rem;
    display: none;
}

.night #color-div{
    border: 1px solid #666;
}
.night .alert-warning{
    background-color: #181a1b;
    color: #aaa;
}
.night #tool-result{
    background-color: #222;
    border: 1px solid #444;
    color: #bbb;
}