body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: #e0f7fa;
    color: #333;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
}

.calculator {
    background: #ffffff;
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 0 15px rgba(0, 0, 0, 0.1);
    width: 90%;
    max-width: 600px;
    text-align: center;
}

.calculator h1 {
    margin-bottom: 20px;
    color: #1e90ff;
    font-size: 1.8em;
}

form {
    display: flex;
    flex-direction: column;
}

.form-group {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
}

.form-row {
    flex: 0 0 48%;
    display: flex;
    flex-direction: column;
    margin-bottom: 15px;
}

label {
    margin: 5px 0;
    text-align: left;
    color: #666;
}

input, select {
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 5px;
    background: #f9f9f9;
    color: #333;
    font-size: 1em;
    box-sizing: border-box;
    width: 100%;
}

input[type="date"] {
    cursor: pointer;
}

button {
    padding: 10px;
    background: linear-gradient(90deg, #1e90ff, #00bfff);
    border: none;
    border-radius: 5px;
    color: white;
    font-weight: bold;
    cursor: pointer;
    transition: background 0.5s ease;
    margin-top: 20px;
    width: 100%;
    box-sizing: border-box;
}

button:hover {
    background: linear-gradient(90deg, #00bfff, #1e90ff);
}

#results {
    margin-top: 20px;
    background: #f9f9f9;
    padding: 10px;
    border-radius: 5px;
    border: 1px solid #ddd;
}

#results p {
    margin: 5px 0;
    font-size: 1.1em;
    color: #333;
}

#remainingValue, #overchargeAmount {
    font-weight: bold;
    color: #1e90ff;
}

#api-info {
    margin-top: 20px;
    font-size: 0.9em;
    color: #666;
}

@media (max-width: 768px) {
    .form-row {
        flex: 0 0 100%;
    }
}
@media (max-width: 768px) {
  .calculator {
    padding-top: 150px; /* 增加顶部内边距 */
    margin-top: 20px;  /* 增加顶部外边距 */
  }
}