:root {
    --primary-color: #0056b3;
    --secondary-color: #6c757d;
    --success-color: #28a745;
    --warning-color: #ffc107;
    --danger-color: #dc3545;
    --light-color: #f8f9fa;
    --dark-color: #343a40;
    --border-color: #dee2e6;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: #f5f5f5;
    padding: 20px;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    background-color: white;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    padding: 20px;
}

h1, h2, h3 {
    color: var(--primary-color);
    margin-bottom: 16px;
}

.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 16px;
}

.app-controls {
    display: flex;
    gap: 12px;
}

button {
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: 4px;
    padding: 8px 16px;
    cursor: pointer;
    transition: background-color 0.2s;
}

button:hover {
    background-color: #004494;
}

button.secondary {
    background-color: var(--secondary-color);
}

button.secondary:hover {
    background-color: #5a6268;
}

button.success {
    background-color: var(--success-color);
}

button.success:hover {
    background-color: #218838;
}

button.warning {
    background-color: var(--warning-color);
    color: black;
}

button.warning:hover {
    background-color: #e0a800;
}

button.danger {
    background-color: var(--danger-color);
}

button.danger:hover {
    background-color: #c82333;
}

.app-layout {
    display: flex;
    gap: 24px;
}

.sidebar {
    width: 300px;
    flex-shrink: 0;
}

.main-content {
    flex-grow: 1;
}

.form-group {
    margin-bottom: 16px;
}

label {
    display: block;
    margin-bottom: 4px;
    font-weight: 500;
}

input[type="text"],
input[type="number"],
select {
    width: 100%;
    padding: 8px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 16px;
}

.empty-message {
    color: var(--secondary-color);
    text-align: center;
    padding: 40px 0;
}

.export-section {
    margin-top: 24px;
    border-top: 1px solid var(--border-color);
    padding-top: 16px;
}

.tools-section {
    margin-top: 24px;
    border-top: 1px solid var(--border-color);
    padding-top: 16px;
}

.tooltip {
    position: absolute;
    background-color: #333;
    color: white;
    padding: 4px 8px;
    border-radius: 4px;
    font-size: 12px;
    z-index: 100;
    pointer-events: none;
    white-space: nowrap;
}

/* Modal styles */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0,0,0,0.4);
}

.modal-content {
    background-color: white;
    margin: 15% auto;
    padding: 20px;
    border-radius: 8px;
    width: 400px;
    max-width: 80%;
    box-shadow: 0 4px 8px rgba(0,0,0,0.2);
}

.close {
    color: #aaa;
    float: right;
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
}

.close:hover,
.close:focus {
    color: black;
    text-decoration: none;
}
/* footnote */
.page-footer {
    margin-top: 40px;
    padding-top: 20px;
    border-top: 1px solid var(--border-color);
    text-align: center;
    color: var(--secondary-color);
    font-size: 14px;
}

.page-footer p {
    margin-bottom: 8px;
}

.footer-note {
    font-size: 12px;
    opacity: 0.8;
}
@media (max-width: 768px) {
    .app-layout {
        flex-direction: column;
    }

    .sidebar {
        width: 100%;
    }
}