section{
    display:flex;
    flex-direction:column;
    min-height:calc(100vh - 50px - 220px);
    padding:20px 0 0 0;
}
.search-row{
    display:flex;
    gap:8px;
    margin-bottom:16px;
}
#bigIiput{
    border:1px solid #e2e8f0;
    border-radius:8px;
    box-sizing:border-box;
    color:#0f172a;
    flex:1;
    font-size:16px;
    padding:10px 14px;
}
#bigIiput:focus{
    border-color:#3964fe;
    outline:none;
}
#bigIiput::placeholder{
    color:#94a3b8;
}
#inputButton{
    background:#3964fe;
    border:none;
    border-radius:8px;
    color:#fff;
    cursor:pointer;
    font-size:14px;
    height:42px;
    padding:0 20px;
    transition:background 0.15s;
}
#inputButton:hover{
    background:#2d4fd6;
}
#inputButton:active{
    transform:scale(.97);
}
.columns{
    display:flex;
    flex:1;
    gap:16px;
    min-height:0;
}
.col-card{
    background:#fff;
    border:1px solid #e2e8f0;
    border-radius:8px;
    display:flex;
    flex:1;
    flex-direction:column;
    min-width:0;
    overflow:hidden;
}
.col-head{
    align-items:center;
    border-bottom:1px solid #e2e8f0;
    color:#0f172a;
    display:flex;
    font-size:14px;
    font-weight:500;
    justify-content:space-between;
    padding:12px 16px;
}
.grade{
    background:#3964fe;
    border-radius:4px;
    color:#fff;
    display:inline-block;
    flex-shrink:0;
    font-size:13px;
    font-weight:600;
    height:22px;
    line-height:22px;
    text-align:center;
    visibility:hidden;
    width:36px;
}
.grade:not(:empty){
    visibility:visible;
}
.showBox{
    flex:1;
    overflow:auto;
    padding:8px;
}
.showBox > div{
    border-radius:4px;
    color:#475569;
    cursor:pointer;
    font-size:13px;
    line-height:1.6;
    padding:6px 8px;
    transition:background 0.15s;
}
.showBox > div:hover{
    background:#edf3fe;
    color:#0f172a;
}
.mark{
    background:#fef08a;
    border-radius:2px;
    padding:0 2px;
}
#calculatorNav{
    top:3px;
}
@media (max-width:768px){
    section{
        min-height:0;
        padding:8px;
    }
    .columns{
        flex-direction:column;
    }
    .col-card{
        max-height:350px;
    }
    #calculatorNav{
        display:none;
    }
}