body {
    font-family: sans-serif;
    display: flex;
    justify-content: center;
    align-items: flex-start; /* Align items to the top */
    min-height: 100vh;
    background-color: #f0f0f0;
    margin: 0;
    padding-top: 20px; /* Add some padding at the top */
}

.container {
    background-color: #fff;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    width: 90%;
    max-width: 400px; /* Limit max width for better appearance */
    display: flex;
    flex-direction: column;
}

header {
    text-align: center;
    margin-bottom: 15px;
    border-bottom: 1px solid #ccc;
    padding-bottom: 10px;
}

header h1 {
    margin: 0 0 5px 0;
    font-size: 1.5em;
}

#date-display {
    font-size: 0.9em;
    color: #555;
}

.calculator {
    margin-bottom: 20px;
}

.display {
    background-color: #eee;
    border-radius: 5px;
    padding: 10px;
    margin-bottom: 15px;
}

.display .total-label,
.display .input-label {
    font-size: 0.8em;
    color: #666;
    margin-bottom: 2px;
}

.display input {
    width: calc(100% - 10px); /* Adjust width considering padding */
    padding: 8px 5px;
    font-size: 1.8em;
    text-align: right;
    border: none;
    background-color: transparent;
    margin-bottom: 5px;
    box-sizing: border-box;
}

.buttons {
    display: flex;
    gap: 10px;
}

.numpad {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
    flex-grow: 3; /* Numpad takes more space */
}

.operators {
    display: flex;
    flex-direction: column;
    gap: 10px;
    flex-grow: 1; /* Operators take less space */
}

button {
    padding: 15px;
    font-size: 1.2em;
    border: 1px solid #ccc;
    border-radius: 5px;
    background-color: #f9f9f9;
    cursor: pointer;
    transition: background-color 0.2s;
}

button:hover {
    background-color: #e0e0e0;
}

button:active {
    background-color: #d0d0d0;
}

#clear-btn {
    background-color: #ffdddd;
}

#clear-btn:hover {
    background-color: #ffcccc;
}

.operator-btn.large-btn {
    padding: 25px 15px; /* Make operator buttons taller */
    font-size: 1.5em;
    font-weight: bold;
    background-color: #d4eaff;
}

.operator-btn.large-btn:hover {
    background-color: #bce0ff;
}

/* #undo-btn {
    background-color: #fffacd;
}

#undo-btn:hover {
    background-color: #fff0a0;
} */

.history-section {
    border-top: 1px solid #ccc;
    padding-top: 15px;
}

.history-section h2 {
    text-align: center;
    margin-top: 0;
    margin-bottom: 10px;
    font-size: 1.2em;
}

#history-log {
    height: 100px;
    overflow-y: auto;
    border: 1px solid #eee;
    padding: 5px;
    margin-bottom: 10px;
    background-color: #fdfdfd;
    font-size: 0.9em;
    line-height: 1.4;
}

#save-history-btn {
    display: block;
    width: 100%;
    padding: 10px;
    background-color: #d4ffd4;
}

#save-history-btn:hover {
    background-color: #bcf0bc;
}

/* Responsive adjustments if needed */
@media (max-width: 350px) {
    button {
        padding: 12px;
        font-size: 1em;
    }
    .operator-btn.large-btn {
        padding: 20px 10px;
        font-size: 1.3em;
    }
    .display input {
        font-size: 1.5em;
    }
}