:root {
    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --bg: #ffffff;
    --border: #e5e7eb;
    --text: #1f2937;
    --text-secondary: #6b7280;
    --success: #10b981;
    --error: #ef4444;
    --info: #3b82f6;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.5;
    color: var(--text);
    background-color: #f9fafb;
    padding: 1rem;
    max-width: 800px;
    margin: 0 auto;
}

h1 {
    font-size: 1.5rem;
    font-weight: 600;
    text-align: center;
    margin-bottom: 1.5rem;
    color: var(--text);
}

.control-panel {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1rem;
    padding: 0.75rem;
    background: var(--bg);
    border-radius: 0.5rem;
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05);
}

.file-list {
    background: var(--bg);
    border-radius: 0.5rem;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    overflow: hidden;
    margin-bottom: 1.5rem;
}

.file-item {
    display: flex;
    align-items: center;
    padding: 0.75rem 1rem;
    border-bottom: 1px solid var(--border);
    transition: background-color 0.15s ease;
}

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

.file-item:hover {
    background-color: #f3f4f6;
}

.file-checkbox {
    margin-right: 0.75rem;
    width: 1.125rem;
    height: 1.125rem;
    cursor: pointer;
}

.file-name {
    flex: 1;
    word-break: break-word;
    font-size: 0.9375rem;
}

.buttons {
    display: flex;
    justify-content: center;
    margin-bottom: 1rem;
}

button {
    padding: 0.625rem 1.5rem;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: 0.375rem;
    font-size: 0.9375rem;
    font-weight: 500;
    cursor: pointer;
    transition: background-color 0.2s ease;
}

button:hover {
    background: var(--primary-hover);
}

button:disabled {
    background: #d1d5db;
    cursor: not-allowed;
}

.status {
    padding: 0.75rem;
    border-radius: 0.375rem;
    text-align: center;
    font-size: 0.875rem;
    margin-top: 1rem;
    display: none;
}

.status.visible {
    display: block;
}

.status.info {
    background-color: #eff6ff;
    color: var(--info);
}

.status.success {
    background-color: #ecfdf5;
    color: var(--success);
}

.status.error {
    background-color: #fee2e2;
    color: var(--error);
}

.loading-placeholder {
    padding: 1.5rem;
    text-align: center;
    color: var(--text-secondary);
}

.loading-spinner {
    display: inline-block;
    width: 1rem;
    height: 1rem;
    border: 2px solid rgba(0,0,0,0.1);
    border-radius: 50%;
    border-top-color: var(--primary);
    animation: spin 1s ease-in-out infinite;
    margin-right: 0.5rem;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

a {
    text-decoration: none;
    color: var(--primary);
    transition: text-decoration 0.2s ease;
}

a:hover {
    text-decoration: underline;
    color: var(--primary-hover);
}