input框输入中文是正常的居中 输入英文和数字就会不同程度的向上

.input_box {  
        font-size: 30rpx;  
        height: 70rpx;  
        line-height: 70rpx;  
        display: flex;  
        padding-bottom: 30rpx;  
    }  

    .input_box .search_input {  
        width: 80%;  
        height: 100%;  
        border: 1px solid #FFD988;  
        border-right: 0;  
        display: flex;  
    }  

    .input_box input {  
        height: 100%;  
        width: 100%;  
        font-size: 30rpx;  
        padding-left: 20rpx;  
    }  

    .input_box .cancel {  
        width: 50rpx;  
        height: 50rpx;  
        background-image: url(../../static/cancel.png);  
        background-repeat: no-repeat;  
        background-size: 100%;  
        background-position: center center;  
        margin: auto 20rpx;  
    }  

    .input_box .search {  
        width: 20%;  
        text-align: center;  
        height: 100%;  
        border: 1px solid #FFD988;  
        background-color: #FFD988;  
    }