/* DEFAULT STYLINH RESET */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: Cambria, Cochin, Georgia, Times, 'Times New Roman', serif;
}

body {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100vh;
    background: linear-gradient(45deg, #cccccc, #2fc42f);
}

.container {
    background-color: #979991;
    box-shadow:
            0 12px 32px 0 rgba(31, 38, 135, 0.37),
            0 2px 0 #fff inset,
            0 -4px 16px 0 rgba(0,0,0,0.18) inset,
            0 8px 24px 0 rgba(0,0,0,0.25);
    overflow: hidden;
    padding: 5px 20px 20px 20px;
    border-radius: 15px;
    border: 2px solid black;
}

h2 {
    text-align: center;
    padding: 10px;
    letter-spacing: 1px;
    font-size: 2rem;
    font-weight: 700;
    color: #222;
    text-shadow: 0 2px 6px rgba(0,0,0,0.08), 0 1px 0 #fff;
}

tr {
    display: flex;
    flex-direction: row;
    justify-content: space-between;
    align-items: stretch;
    padding: 2px;
}

td {
    flex: 1;
    padding: 2px;
}

.text-field {
    width: auto;
    height: 90px;
    padding: 20px 10px;
    color: #222;
    font-size: 2rem;
    font-weight: 500;
    letter-spacing: 1px;
    text-align: right;
    text-shadow: 0 1px 2px rgba(0,0,0,0.10);
    border: 3px solid black;
    border-radius: 15px;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.15) inset;
    background: linear-gradient(180deg , #fff, #e0e0e0);
}

.btn {
    width: 100%;
    padding: 20px 20px;
    background-color: #e6e6dd;
    color: #333;
    font-size: 2rem;
    font-weight: 400;
    border: 3px solid black;
    cursor: pointer;
    border-radius: 15px;
    transition: 0.3s;
}

#btn-equal {
    width: 100%;
    height: 90px;
    background-color: #e6e6dd;
    color: green;
    font-size: 3rem;
    font-weight: 400;
    border: 3px solid black;
    cursor: pointer;
    border-radius: 15px;
    transition: 0.3s;
}

#btn-clear {
    width: 115px;
    height: 80px;
    background-color: #e6e6dd;
    color: red;
    font-size: 3rem;
    font-weight: 400;
    border: 3px solid black;
    cursor: pointer;
    border-radius: 15px;
    transition: 0.3s;
}

.btn, #btn-equal, #btn-clear {
    box-sizing: border-box;
    font-family: 'Segoe UI', Cambria, Cochin, Georgia, Times, 'Times New Roman', serif;
    font-weight: 600;
    letter-spacing: 1px;
    text-shadow: 0 1px 2px rgba(0,0,0,0.10);
    min-height: 90px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.2), 0 2px 0 #fff inset;
    background: linear-gradient(180deg, #e6e6dd 60%, #bdbdb3 100%);
    border-bottom: 4px solid #444;
}

.btn:hover,
#btn-equal:hover,
#btn-clear:hover,
.btn.keyPressed,
#btn-equal.keyPressed,
#btn-clear.keyPressed {
    background: linear-gradient(180deg, #2fc42f 60%, #1e8c1e 100%);
    color: white;
    box-shadow: 0 1px 2px rgba(0,0,0,0.4), 0 1px 0 #fff inset;
    border-bottom: 2px solid #155d15;
    transform: translateY(2px);
}