/* Reset */
*{
    margin:0;
    padding:0;
    box-sizing:border-box;
    font-family: Arial, Helvetica, sans-serif;
}

/* Center calculator */
body{
    height:100vh;
    display:flex;
    justify-content:center;
    align-items:center;
    background:#f3f3f3;
}

/* Calculator container */
.container{
    width:425px;
    background:#2c2f36;
    border-radius:15px;
    padding:20px;
    box-shadow:0 10px 30px rgba(0,0,0,0.3);
}

/* ---------------- DISPLAY ---------------- */

.input{
    display: none;
}
.display{
    background:#1e2127;
    color:white;
    border-radius:10px;
    padding:15px;
    margin-bottom:20px;
    height: 200px;
    width: 385px;
    display:flex;
    flex-direction:column;
    align-items:flex-end;
}

.history{
    height: 50%;
    font-size:26px;
    color:#a0a0a0;
    display: flex;
    align-items: flex-end;
    overflow-y: auto;
}

.answer{
    height: 100%;
    font-size: 50px;
    font-weight:bold;
    display: flex;
    align-items: flex-end;
    overflow-y: auto;
}

/* ---------------- BUTTON GRID ---------------- */

.buttons{
    display:grid;
    grid-template-columns: repeat(4,1fr);
    gap:10px;
}

/* Button style */
.buttons button{
    height:55px;
    border:none;
    border-radius:8px;
    font-size:18px;
    cursor:pointer;
    transition:0.2s;

    background:#3b3f48;
    color:white;
}

/* Hover effect */
.buttons button:hover{
    background:#50545e;
}

/* Operator buttons */
.buttons button:nth-child(4n){
    background:#ff9500;
}

/* Plus button */
.plus-btn{
    grid-row: span 2;
    background:#ff9500;
    height: 100% !important;
    width: 100%;
}

/* Equal button */
.eq-btn{
    grid-column: span 2;
    background:#34c759;
}

/* Equal hover */
.eq-btn:hover{
    background:#28a745;
}


/* ---------------------media query------------------------------ */

@media (max-width: 480px) {

    .container{
        width: 100%;
        padding: 10px;
    }

    .display{
        height: 150px;
        width: 100%;
    }

}