:root {
    --bg-color: #f4f4f9;
    --panel-bg: #ffffff;
    --text-color: #333;
    --accent-color: #007acc;
    --accent-hover: #005f9e;
    --border-color: #ddd;
}

* {
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Meiryo", sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    margin: 0;
    padding: 20px;
    display: flex;
    justify-content: center;
}

.container {
    max-width: 1200px;
    width: 100%;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

header {
    text-align: center;
    margin-bottom: 10px;
}

main {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

@media (max-width: 768px) {
    main {
        grid-template-columns: 1fr;
    }
}

.panel {
    background: var(--panel-bg);
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.05);
    border: 1px solid var(--border-color);
}

h2 {
    margin-top: 0;
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 8px;
    font-size: 1.2rem;
}

h3 {
    font-size: 1rem;
    margin-bottom: 8px;
    color: #555;
    margin-top: 15px;
}

h3:first-child {
    margin-top: 0;
}

.category-group {
    background: #f9f9f9;
    padding: 10px;
    border-radius: 4px;
    margin-bottom: 10px;
    border: 1px solid #eee;
}

.grid-2 {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 5px;
}

label {
    display: block;
    margin-bottom: 5px;
    cursor: pointer;
    font-size: 0.95rem;
}

.form-row {
    margin-bottom: 15px;
    display: flex;
    gap: 15px;
}

.form-row label {
    flex: 1;
}

input[type="text"],
input[type="number"],
select {
    width: 100%;
    padding: 8px;
    border: 1px solid #ccc;
    border-radius: 4px;
    margin-top: 4px;
}

small {
    display: block;
    color: #777;
    margin-top: 4px;
    font-size: 0.8rem;
    line-height: 1.2;
}

.highlight {
    font-weight: bold;
    color: var(--accent-color);
}

.sub-note {
    font-size: 0.8rem;
    color: #777;
    margin-left: 20px;
    margin-bottom: 5px;
}

/* Output Area */
#outputXML {
    width: 100%;
    height: 400px;
    font-family: 'Consolas', 'Monaco', monospace;
    font-size: 0.85rem;
    padding: 10px;
    border: 1px solid var(--border-color);
    background: #fafafa;
    white-space: pre;
    overflow: auto;
    resize: vertical;
}

.stats {
    font-size: 0.9rem;
    background: #eef;
    padding: 8px;
    border-radius: 4px;
    margin-bottom: 10px;
    color: #444;
}

.actions {
    display: flex;
    gap: 10px;
    margin-top: 15px;
}

button {
    padding: 10px 20px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 500;
    transition: background-color 0.2s;
    background: #ddd;
    color: #333;
}

button.primary {
    background-color: var(--accent-color);
    color: white;
}

button:hover {
    opacity: 0.9;
}