body{font-size:12px;}
.flex-box .b{/*background:#0f0;*/}
.logo{width:180px;height:auto;}

.flex-box{width:800px;}
.flex-box .a{width:200px;/*background:blue;*/text-align:left;}
.flex-box .b{flex-grow:1;/*background:#0ff*/;text-align:left;}
.flex-box .c{width:200px;/*background:red;*/text-align:left;}