:root {
    --primary-color: #4a90e2;
    --primary-hover: #357abd;
    --bg-color: #f5f7fa;
    --panel-bg: #ffffff;
    --text-color: #333333;
    --border-color: #e1e4e8;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --radius: 8px;
}

* {
    box-sizing: border-box;
}

body {
    font-family: 'Noto Sans JP', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    margin: 0;
    padding: 0;
    line-height: 1.5;
}

.app-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--spacing-md);
}

header {
    text-align: center;
    margin-bottom: var(--spacing-lg);
}

header h1 {
    margin: 0;
    color: var(--primary-color);
}

header p {
    margin: var(--spacing-sm) 0 0;
    color: #666;
}

main {
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: var(--spacing-lg);
    align-items: start;
}

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

.settings-panel {
    background: var(--panel-bg);
    padding: var(--spacing-md);
    border-radius: var(--radius);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

.setting-group {
    margin-bottom: var(--spacing-lg);
    border-bottom: 1px solid var(--border-color);
    padding-bottom: var(--spacing-md);
}

.setting-group:last-child {
    border-bottom: none;
    margin-bottom: 0;
}

.setting-group h2 {
    font-size: 1.1rem;
    margin-top: 0;
    margin-bottom: var(--spacing-md);
    border-left: 4px solid var(--primary-color);
    padding-left: var(--spacing-sm);
}

.input-row {
    margin-bottom: var(--spacing-sm);
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    align-items: center;
}

.input-row label {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 0.9rem;
}

.input-row.indent {
    margin-left: var(--spacing-lg);
}

input[type="number"],
input[type="text"],
select {
    padding: 4px 8px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 0.9rem;
}

input[type="number"] {
    width: 80px;
}

input[type="color"] {
    width: 40px;
    height: 30px;
    padding: 0;
    border: none;
    cursor: pointer;
}

.ratio-inputs {
    display: flex;
    align-items: center;
    gap: 4px;
}

.ratio-inputs input {
    width: 50px;
}

.secondary-btn {
    background: #e1e4e8;
    border: none;
    padding: 4px 8px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.85rem;
}

.secondary-btn:hover {
    background: #d1d5da;
}

.radio-group {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-sm);
}

.hidden {
    display: none;
}

.main-content {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.input-area {
    background: var(--panel-bg);
    padding: var(--spacing-md);
    border-radius: var(--radius);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

.input-area h2,
.preview-area h2 {
    margin-top: 0;
    font-size: 1.2rem;
}

.hint {
    font-size: 0.85rem;
    color: #666;
    margin-bottom: var(--spacing-sm);
}

textarea {
    width: 100%;
    height: 150px;
    padding: var(--spacing-sm);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    resize: vertical;
    font-family: inherit;
    margin-bottom: var(--spacing-md);
}

.primary-btn {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 12px 24px;
    border-radius: var(--radius);
    font-size: 1rem;
    font-weight: bold;
    cursor: pointer;
    width: 100%;
    transition: background 0.2s;
}

.primary-btn:hover {
    background: var(--primary-hover);
}

.preview-area {
    background: var(--panel-bg);
    padding: var(--spacing-md);
    border-radius: var(--radius);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

.preview-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-md);
}

.action-btn {
    background: #28a745;
    color: white;
    border: none;
    padding: 8px 16px;
    border-radius: 4px;
    cursor: pointer;
    font-weight: bold;
}

.action-btn:hover {
    background: #218838;
}

.preview-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: var(--spacing-md);
    min-height: 200px;
}

.preview-item {
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    padding: var(--spacing-sm);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
    background: #fafafa;
}

.preview-image-wrapper {
    flex-grow: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    background: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" width="20" height="20" viewBox="0 0 20 20"><rect width="10" height="10" fill="%23eee"/><rect x="10" y="10" width="10" height="10" fill="%23eee"/></svg>');
    overflow: hidden;
    border: 1px solid #ddd;
}

.preview-image-wrapper img {
    max-width: 100%;
    max-height: 200px;
    object-fit: contain;
}

.preview-text {
    font-size: 0.8rem;
    color: #666;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.download-btn {
    background: #6c757d;
    color: white;
    border: none;
    padding: 4px 8px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.85rem;
    width: 100%;
}

.download-btn:hover {
    background: #5a6268;
}

.placeholder-msg {
    grid-column: 1 / -1;
    text-align: center;
    color: #999;
    padding: var(--spacing-lg);
}