/* css/calculator.css */
.calculator-section {
    margin: 30px 0;
    padding: 20px;
    background-color: #f9f9f9;
    border-radius: 8px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.calculator {
    max-width: 300px;
    box-sizing: border-box;
    margin: 0 auto;
    border: 1px solid #ccc;
    border-radius: 5px;
    padding: 15px;
    background-color: #fff;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.calculator-display {
    width: 100%; /* 继承父容器宽度 */
    box-sizing: border-box; /* 重要！ */
    margin-bottom: 15px;
}

.calculator-display input {
    width: 100%;
    box-sizing: border-box; /* 包含padding和border */
    padding: 10px 15px;
    font-size: 1.5em;
    text-align: right;
    border: 1px solid #ddd;
    border-radius: 4px;
    background-color: #f8f8f8;
}

.calculator-keys {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    grid-template-rows: repeat(5, auto);
    grid-template-areas:
        "add subtract multiply divide"
        "seven eight nine ac"
        "four five six ac"
        "one two three equal"
        "zero zero dot equal";
    gap: 10px; /* 改用gap属性更标准 */
}

.calculator-keys button {
    padding: 15px;
    font-size: 1.2em;
    border: 1px solid #ddd;
    border-radius: 3px;
    background-color: #f5f5f5;
    cursor: pointer;
    transition: background-color 0.3s;
}

.calculator-keys button:hover {
    background-color: #e9e9e9;
}

.calculator-keys .operator {
    background-color: #f0a500;
    color: white;
}

.calculator-keys .operator.add {
    grid-area: add;
}

.calculator-keys .operator.subtract {
    grid-area: subtract;
}

.calculator-keys .operator.multiply {
    grid-area: multiply;
}

.calculator-keys .operator.divide {
    grid-area: divide;
}

.calculator-keys button[value="7"] {
    grid-area: seven;
}

.calculator-keys button[value="8"] {
    grid-area: eight;
}

.calculator-keys button[value="9"] {
    grid-area: nine;
}

.calculator-keys button[value="4"] {
    grid-area: four;
}

.calculator-keys button[value="5"] {
    grid-area: five;
}

.calculator-keys button[value="6"] {
    grid-area: six;
}

.calculator-keys button[value="1"] {
    grid-area: one;
}

.calculator-keys button[value="2"] {
    grid-area: two;
}

.calculator-keys button[value="3"] {
    grid-area: three;
}

.calculator-keys button[value="0"] {
    grid-area: zero;
    grid-column: span 2; /* 横跨两列 */
}

.calculator-keys button[value="."] {
    grid-area: dot;
}

.calculator-keys .all-clear {
    grid-area: ac;
    grid-row: span 2; /* 纵跨两行 */
    background-color: #e74c3c;
    color: white;
}

.calculator-keys .all-clear:hover {
    background-color: #d62c1a;
}

.calculator-keys .equal-sign {
    grid-area: equal;
    grid-row: span 2; /* 纵跨两行 */
    background-color: #2e86c0;
    color: white;
}

.calculator-keys .equal-sign:hover {
    background-color: #2778b0;
}