:root {
    --primary: #10b981;
    --primary-hover: #059669;
    --bg: #f8fafc;
    --card-bg: #ffffff;
    --text: #1e293b;
    --text-muted: #64748b;
    --border: #e2e8f0;
    --input-bg: #f1f5f9;
    --success: #10b981;
    --error: #ef4444;
    --warning: #f59e0b;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
}

.container {
    max-width: 720px;
    margin: 0 auto;
    padding: 24px 16px;
}

h1 {
    text-align: center;
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 4px;
}

.subtitle {
    text-align: center;
    color: var(--text-muted);
    font-size: 0.875rem;
    margin-bottom: 24px;
}

.card {
    background: var(--card-bg);
    border-radius: 12px;
    padding: 20px;
    margin-bottom: 16px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.06);
    border: 1px solid var(--border);
}

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

.form-group:last-child {
    margin-bottom: 0;
}

.form-group label {
    display: block;
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 6px;
    color: var(--text);
}

.file-label {
    display: block;
    padding: 20px;
    border: 2px dashed var(--border);
    border-radius: 8px;
    text-align: center;
    cursor: pointer;
    transition: all 0.2s;
    color: var(--text-muted);
    font-size: 0.9rem;
}

.file-label:hover,
.file-label.dragover {
    border-color: var(--primary);
    background: #ecfdf5;
    color: var(--primary);
}

.file-name {
    font-size: 0.8rem;
    color: var(--primary);
    margin-top: 4px;
    word-break: break-all;
}

/* Version Switch */
.version-switch {
    display: flex;
    gap: 0;
    background: var(--input-bg);
    border-radius: 8px;
    padding: 3px;
    position: relative;
}

.version-switch input[type="radio"] {
    display: none;
}

.version-switch label {
    flex: 1;
    text-align: center;
    padding: 8px 4px;
    font-size: 0.85rem;
    font-weight: 500;
    cursor: pointer;
    border-radius: 6px;
    transition: all 0.2s;
    color: var(--text-muted);
    position: relative;
    z-index: 1;
}

.version-switch input[type="radio"]:checked + label {
    background: var(--primary);
    color: white;
    box-shadow: 0 1px 3px rgba(16,185,129,0.3);
}

.custom-input-group {
    display: none;
    margin-top: 12px;
}

.custom-input-group input {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 0.875rem;
    font-family: 'Courier New', monospace;
    background: var(--input-bg);
    transition: border-color 0.2s;
}

.custom-input-group input:focus {
    outline: none;
    border-color: var(--primary);
}

.preset-info {
    background: #ecfdf5;
    border: 1px solid #a7f3d0;
    border-radius: 8px;
    padding: 10px 14px;
    font-size: 0.8rem;
    color: #065f46;
    margin-top: 12px;
    display: none;
    word-break: break-all;
}

/* Buttons */
.actions {
    display: flex;
    gap: 12px;
}

.btn {
    flex: 1;
    padding: 12px 20px;
    border: none;
    border-radius: 8px;
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    display: none;
}

.btn.active {
    display: block;
}

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

.btn-primary:hover:not(:disabled) {
    background: var(--primary-hover);
    box-shadow: 0 2px 8px rgba(16,185,129,0.3);
}

.btn-secondary {
    background: var(--input-bg);
    color: var(--text);
    border: 1px solid var(--border);
}

.btn-secondary:hover:not(:disabled) {
    background: #e2e8f0;
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

/* Editor */
.editor-container {
    display: none;
    background: var(--card-bg);
    border-radius: 12px;
    border: 1px solid var(--border);
    overflow: hidden;
}

.editor-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 14px 20px;
    background: var(--input-bg);
    border-bottom: 1px solid var(--border);
}

.editor-header h3 {
    font-size: 0.9rem;
    font-weight: 600;
}

.editor-actions {
    display: flex;
    gap: 8px;
}

.editor-btn {
    padding: 6px 14px;
    border: none;
    border-radius: 6px;
    font-size: 0.8rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
}

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

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

.editor-btn-secondary {
    background: var(--input-bg);
    color: var(--text);
    border: 1px solid var(--border);
}

.editor-btn-secondary:hover {
    background: #e2e8f0;
}

.editor-btn-cancel {
    background: var(--input-bg);
    color: var(--text-muted);
    border: 1px solid var(--border);
}

.editor-btn-cancel:hover {
    background: #e2e8f0;
}

.editor-content {
    width: 100%;
    min-height: 300px;
    max-height: 500px;
    padding: 16px;
    border: none;
    resize: vertical;
    font-family: 'Courier New', Consolas, monospace;
    font-size: 0.85rem;
    line-height: 1.5;
    background: var(--card-bg);
    color: var(--text);
}

.editor-content:focus {
    outline: none;
}

/* Status Message */
.status-message {
    padding: 10px 16px;
    border-radius: 8px;
    font-size: 0.85rem;
    margin-bottom: 16px;
    display: none;
}

.status-success {
    background: #ecfdf5;
    color: #065f46;
    border: 1px solid #a7f3d0;
}

.status-error {
    background: #fef2f2;
    color: #991b1b;
    border: 1px solid #fecaca;
}

.file-type-tip {
    background: #eff6ff;
    border: 1px solid #bfdbfe;
    border-radius: 8px;
    padding: 10px 14px;
    font-size: 0.8rem;
    color: #1e40af;
    margin-top: 12px;
    display: none;
}

/* Footer */
.footer {
    text-align: center;
    padding: 20px 0;
    font-size: 0.8rem;
    color: var(--text-muted);
}

.footer a {
    color: var(--primary);
    text-decoration: none;
}

.footer a:hover {
    text-decoration: underline;
}

/* Responsive */
@media (max-width: 480px) {
    .container {
        padding: 16px 12px;
    }

    .card {
        padding: 16px;
    }

    h1 {
        font-size: 1.25rem;
    }

    .version-switch label {
        font-size: 0.8rem;
        padding: 8px 2px;
    }

    .actions {
        flex-direction: column;
    }
}