/* Body styling for a centered calculator */
body {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
    background: linear-gradient(135deg, #e7701b, #383cb6);
    font-family: 'Arial', sans-serif;
}

/* Calculator container styling */
.calculator {
    border-radius: 10px;
    padding: 20px;
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.782);
    background: #fff;
    display: flex;
    flex-direction: column;
    align-items: center;
}

/* Screen styling */
.calculator-screen {
    width: 100%;
    height: 60px;
    background: #000000;
    color: #fff;
    text-align: right;
    font-size: 2rem;
    padding: 10px;
    border-radius: 10px;
    margin-bottom: 20px;
    box-shadow: inset 0 0 10px rgba(0, 0, 0, 0.1);
}

/* Grid layout for calculator keys */
.calculator-keys {
    width: 100%;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
}

/* Common button styling */
.key {
    background: #f4f4f4;
    border: none;
    border-radius: 5px;
    font-size: 1.5rem;
    padding: 20px;
    box-shadow: 0 5px 10px rgba(0, 0, 0, 0.1);
    cursor: pointer;
    transition: background 0.2s, transform 0.2s;
}
.key:hover {
    background: linear-gradient(90deg, #f6e604, #ed18c9);
}

/* Button active state */
.key:active {
    background: #ccc;
    transform: scale(0.95);
}

/* Operator button styling */
.operator {
    background: #ff9500;
    color: #fff;
}

/* Operator button active state */
.operator:active {
    background: #e08900;
}
.operator:hover {
    background: linear-gradient(120deg, #383cb6, #222);
}

/* Equal sign button styling */
.equal-sign {
    grid-column: span 4;
    background: #18e10d;
    color: #fff;
}
.equal-sign:hover {
    color: rgb(0, 0, 0);
    background: #383cb6;
}

/* Equal sign button active state */
.equal-sign:active {
    background: #2ca823;
}

/* All clear button styling */
.all-clear {
    background: #dc3545;
    color: #fff;
}

/* All clear button active state */
.all-clear:active {
    background: #c82333;
}
.all-clear:hover {
    background: linear-gradient(120deg, #ff0000, #1f127888);
}