#calculator {
    width: 300px;
    margin: 20px auto;
    border: 2px solid #ccc;
    border-radius: 10px;
    padding: 10px;
    background: #f9f9f9;
}
.calc-tabs {
    display: flex;
    justify-content: space-around;
    margin-bottom: 10px;
}
.calc-tab {
    padding: 5px 10px;
    cursor: pointer;
    background: #ddd;
    border: none;
    border-radius: 5px;
}
.calc-tab.active {
    background: #4CAF50;
    color: white;
}
#calc-display {
    width: 100%;
    height: 40px;
    font-size: 18px;
    text-align: right;
    margin-bottom: 10px;
    border-radius: 5px;
    padding: 5px;
}
.calc-buttons {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 5px;
}
.calc-buttons button {
    padding: 10px;
    font-size: 16px;
    border: none;
    background: #eee;
    border-radius: 5px;
    cursor: pointer;
}
.calc-buttons button:hover {
    background: #ddd;
}
.scientific-mode {
    margin-top: 10px;
    grid-template-columns: repeat(4, 1fr);
}