.div_parent{
        min-height: 200px; 
        background: #ffffff;
        width: 900px;
        position:relative; 
        text-align:center;
        margin:0 auto;
    }

    .div_cell{
        background: #fff;
        width:180px;
        height:30px;
        margin: 0 auto;
        text-align: left;
        float: left;
        position: relative;
        left:50px;
    }
.div_block{
    background: #fff;
    width:280px;
    height:30px;
    text-align: left;
    margin: 0 auto;
    left:50px;
}
    A:link {
    FONT-SIZE: 16px;
    COLOR: #333333;
    TEXT-DECORATION: none
}

A:visited {
    FONT-SIZE: 16px;
    COLOR: #333333;
    TEXT-DECORATION: none
}

A:hover {
    FONT-SIZE: 16px;
    COLOR: #043B9C;
    TEXT-DECORATION: underline
}

.btn-submit {
    background-color: var(--primary-color);
    color: #0c0c0c;
    border: none;
    padding: 2px 2px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 16px;
    font-weight: 600;
    transition: background-color 0.3s;
    display: flex;
    align-items: center;
    gap: 8px;
    margin-top: 15px;  /* ADDED 上边距 */
    display: inline-flex;  /* MODIFIED from flex */
}

.btn-submit:hover {
    background-color: #2980b9;
}

.btn-submit:disabled {
    background-color: #95a5a6;
    cursor: not-allowed;
}

#chartCanvas {
    width: 100%;
    height: 10px;
}

.loading-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(255, 255, 255, 0.85);
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
    z-index: 10;
    opacity: 0;
    transition: opacity 0.3s;
    pointer-events: none;
}

.loading-overlay.active {
    opacity: 1;
    pointer-events: auto;
}

/* 加载文字样式  */
.loading-overlay p {
    font-size: 18px;
    color: var(--secondary-color);
    margin-top: 10px;
}

.spinner {
    width: 50px;
    height: 50px;
    border: 5px solid rgba(52, 152, 219, 0.2);
    border-top: 5px solid var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 15px;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}


.chart-container {
    width: 1000px;
    height: 400px;
    margin-top: 20px;
}
.chart-container:last-child {
    margin-bottom: 20px;
}
