body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    margin: 0;
    padding: 20px;
    background-color: #f4f4f4;
    color: #333;
}

.container {
    max-width: 1200px;
    margin: auto;
    background: #fff;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
}

h1, h2 {
    text-align: center;
    color: #2c3e50;
}

.settings {
    margin-bottom: 30px;
    padding: 20px;
    border: 1px solid #ddd;
    border-radius: 5px;
    background-color: #f9f9f9;
}

.input-group {
    display: flex;
    align-items: center;
    margin-bottom: 15px;
}

.input-group label {
    width: 150px;
    font-weight: bold;
    margin-right: 15px;
}

.input-group input {
    flex: 1;
    padding: 10px;
    border: 1px solid #ccc;
    border-radius: 4px;
    font-size: 16px;
}

.input-group button {
    margin-left: 10px;
    width: auto;
    padding: 10px 20px;
    margin-top: 0;
    font-size: 16px;
}

button {
    display: block;
    padding: 12px;
    background-color: #3498db;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 18px;
    margin-top: 20px;
    transition: background-color 0.3s ease;
}

button:hover {
    background-color: #2980b9;
}

.simulation-result {
    margin-top: 20px;
}

#result-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 20px;
}

#result-table th, #result-table td {
    border: 1px solid #ddd;
    padding: 12px;
    text-align: right;
}

#result-table th {
    background-color: #ecf0f1;
    color: #34495e;
    font-weight: bold;
    text-align: center;
}

#result-table tbody tr:nth-child(even) {
    background-color: #f9f9f9;
}

#result-table tbody tr:hover {
    background-color: #f1f1f1;
}

.stock-management {
    margin-top: 30px;
    padding-top: 20px;
    border-top: 1px solid #eee;
}

.stock-management h3 {
    margin-top: 0;
    margin-bottom: 20px;
    text-align: left;
    font-size: 1.2em;
    color: #34495e;
}

.button-group {
    display: flex;
    gap: 10px;
    align-items: center;
    margin-top: 15px;
}

.button-group select {
    flex: 1;
    padding: 10px;
    border-radius: 4px;
    border: 1px solid #ccc;
    background-color: white;
}

.button-group button {
    width: auto;
    padding: 10px 20px;
    margin-top: 0;
    font-size: 16px;
}

#calculate-btn {
    width: 100%;
}

#load-btn {
    background-color: #3498db;
}

#load-btn:hover {
    background-color: #2980b9;
}

#delete-btn {
    background-color: #e74c3c;
}

#delete-btn:hover {
    background-color: #c0392b;
}

.input-group #save-btn {
    background-color: #2ecc71;
}

.input-group #save-btn:hover {
    background-color: #27ae60;
}

#toast-container {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 1000;
}

.toast-message {
    background-color: #333;
    color: #fff;
    padding: 15px 20px;
    border-radius: 5px;
    margin-bottom: 10px;
    opacity: 0;
    transition: opacity 0.5s, transform 0.5s;
    transform: translateX(100%);
}

.toast-message.show {
    opacity: 1;
    transform: translateX(0);
}