/* Dark Theme Calculator */
body {
    background-color: #121212;
    color: white;
    font-family: Arial, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
    overflow: hidden;
}

main {
    background-color: #1e1e1e;
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 0 15px rgba(0, 255, 0, 0.5);
    text-align: center;
    width: 320px;
    display: flex;
    flex-direction: column;
    align-items: center;
    max-height: 90vh;
    overflow-y: auto;
}

#text-area {
    background-color: #2b2b2b;
    padding: 15px;
    border-radius: 5px;
    font-size: 24px;
    text-align: right;
    margin-bottom: 15px;
    box-shadow: inset 0 0 10px rgba(0, 255, 0, 0.3);
    width: 90%;
    min-height: 40px;
    color: white;
    display: flex;
    align-items: center;
    justify-content: flex-end;
    white-space: nowrap;
    overflow: hidden;
}

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

.keys p {
    background-color: #282828;
    padding: 15px;
    border-radius: 5px;
    text-align: center;
    font-size: 20px;
    font-weight: bold;
    cursor: pointer;
    transition: 0.3s;
    box-shadow: 0 0 10px rgba(0, 255, 0, 0.7);
    color: limegreen;
}

.keys p:hover {
    background-color: #00ff00;
    color: #121212;
    box-shadow: 0 0 15px limegreen;
}

.past-calculation {
    background-color: #2b2b2b;
    width: 90%;
    margin-top: 15px;
    padding: 10px;
    border-radius: 5px;
    text-align: right;
    font-size: 16px;
    color: lightgray;
    box-shadow: inset 0 0 10px rgba(0, 255, 0, 0.3);
    max-height: 200px;
    min-height: 100px;
    overflow-y: auto;

}

.past-calculation p {
    margin: 5px 0;
}

#deletePast {
    margin-top: 10px;
    background-color: #ff3333;
    color: white;
    padding: 10px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 16px;
    transition: 0.3s;
    width: 90%;
}

#deletePast:hover {
    background-color: #cc0000;
}