:root {
    --primary-color: #4F46E5;
    --primary-hover: #4338CA;
    --secondary-color: #6B7280;
    --secondary-hover: #4B5563;
    --success-color: #10B981;
    --danger-color: #EF4444;
    --background: #FFFFFF;
    --surface: #F9FAFB;
    --border: #E5E7EB;
    --text-primary: #111827;
    --text-secondary: #6B7280;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --radius: 8px;
    --radius-lg: 12px;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: var(--text-primary);
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

header {
    text-align: center;
    color: white;
    margin-bottom: 2rem;
}

header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.subtitle {
    font-size: 1.125rem;
    opacity: 0.95;
    margin-bottom: 1rem;
}

.language-selector {
    display: flex;
    gap: 0.5rem;
    justify-content: center;
    margin-top: 1rem;
}

.lang-btn {
    padding: 0.375rem 0.75rem;
    background: rgba(255, 255, 255, 0.2);
    border: 1px solid rgba(255, 255, 255, 0.3);
    color: white;
    border-radius: var(--radius);
    cursor: pointer;
    font-size: 0.875rem;
    transition: all 0.2s;
}

.lang-btn:hover {
    background: rgba(255, 255, 255, 0.3);
}

.lang-btn.active {
    background: white;
    color: var(--primary-color);
}

main {
    background: var(--background);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    overflow: hidden;
}

.upload-section {
    padding: 2rem;
    background: var(--surface);
    border-bottom: 1px solid var(--border);
}

.upload-area {
    border: 2px dashed var(--border);
    border-radius: var(--radius-lg);
    padding: 3rem 2rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s;
    background: var(--background);
}

.upload-area:hover {
    border-color: var(--primary-color);
    background: var(--surface);
}

.upload-area.dragover {
    border-color: var(--primary-color);
    background: rgba(79, 70, 229, 0.05);
}

.upload-icon {
    width: 48px;
    height: 48px;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.upload-text {
    font-size: 1.125rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.upload-hint {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.controls-section {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    padding: 2rem;
}

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

.rename-options h2,
.preview-header h2 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.option-tabs {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
}

.tab-btn {
    padding: 0.5rem 1rem;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    cursor: pointer;
    font-size: 0.875rem;
    transition: all 0.2s;
    color: var(--text-secondary);
}

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

.tab-btn.active {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.tab-panel {
    display: none;
}

.tab-panel.active {
    display: block;
}

.form-group {
    margin-bottom: 1rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.375rem;
    font-size: 0.875rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.form-group input[type="text"],
.form-group input[type="number"],
.form-group select {
    width: 100%;
    padding: 0.5rem 0.75rem;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 0.875rem;
    transition: all 0.2s;
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}

.checkbox-group,
.radio-group {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.checkbox-group label,
.radio-group label {
    display: flex;
    align-items: center;
    cursor: pointer;
    font-size: 0.875rem;
}

.checkbox-group input,
.radio-group input {
    margin-right: 0.5rem;
}

.pattern-help {
    background: var(--surface);
    padding: 1rem;
    border-radius: var(--radius);
    margin-top: 1rem;
}

.pattern-help p {
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
}

.pattern-help ul {
    list-style: none;
    font-size: 0.8125rem;
    color: var(--text-secondary);
}

.pattern-help li {
    padding: 0.25rem 0;
}

.preview-section {
    background: var(--surface);
    border-radius: var(--radius);
    padding: 1.5rem;
}

.preview-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.preview-stats {
    display: flex;
    gap: 1rem;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.preview-stats span {
    padding: 0.25rem 0.75rem;
    background: var(--background);
    border-radius: var(--radius);
}

.preview-list {
    max-height: 400px;
    overflow-y: auto;
    margin-bottom: 1.5rem;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--background);
}

.preview-item {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    align-items: center;
    padding: 0.75rem 1rem;
    border-bottom: 1px solid var(--border);
    font-size: 0.875rem;
}

.preview-item:last-child {
    border-bottom: none;
}

.preview-item.changed {
    background: rgba(16, 185, 129, 0.05);
}

.preview-item.changed .preview-new {
    color: var(--success-color);
    font-weight: 500;
}

.preview-original {
    color: var(--text-secondary);
    word-break: break-all;
}

.preview-arrow {
    width: 16px;
    height: 16px;
    color: var(--text-secondary);
    margin: 0 0.5rem;
}

.preview-new {
    word-break: break-all;
}

.action-buttons {
    display: flex;
    gap: 0.75rem;
    justify-content: flex-end;
}

.btn {
    padding: 0.625rem 1.25rem;
    border: none;
    border-radius: var(--radius);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
}

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

.btn-primary:hover {
    background: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

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

.btn-secondary:hover {
    background: var(--secondary-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn:disabled:hover {
    transform: none;
    box-shadow: none;
}

footer {
    text-align: center;
    padding: 2rem;
    color: white;
    font-size: 0.875rem;
    opacity: 0.9;
}

/* スクロールバーのスタイリング */
.preview-list::-webkit-scrollbar {
    width: 6px;
}

.preview-list::-webkit-scrollbar-track {
    background: var(--surface);
    border-radius: 3px;
}

.preview-list::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 3px;
}

.preview-list::-webkit-scrollbar-thumb:hover {
    background: var(--text-secondary);
}