All important stuff is in CSS now

src/components/map/FeaturePropertyPopup.jsx

@@ -2,9 +2,6 @@ import React from 'react'
 import InputBlock from '../inputs/InputBlock'
 import StringInput from '../inputs/StringInput'
 
-import colors from '../../config/colors'
-import { margins, fontSizes } from '../../config/scales'
-
 function displayValue(value) {
   if (typeof value === 'undefined' || value === null) return value;
   if (value instanceof Date) return value.toLocaleString();
@@ -17,24 +14,15 @@ function displayValue(value) {
 function renderProperties(feature) {
   return Object.keys(feature.properties).map(propertyName => {
     const property = feature.properties[propertyName]
-    return <InputBlock key={propertyName} label={propertyName} style={{marginTop: 0, marginBottom: 0}}>
+    return <InputBlock key={propertyName} label={propertyName}>
       <StringInput value={displayValue(property)} style={{backgroundColor: 'transparent'}}/>
     </InputBlock>
   })
 }
 
-const Panel = (props) => {
-  return <div style={{
-    backgroundColor: colors.gray,
-    padding: margins[0],
-    fontSize: fontSizes[5],
-    lineHeight: 1.2,
-  }}>{props.children}</div>
-}
-
 function renderFeature(feature) {
   return <div key={feature.id}>
-    <Panel>{feature.layer['source-layer']}</Panel>
+    <div className="maputnik-popup-layer-id">{feature.layer['source-layer']}</div>
     {renderProperties(feature)}
   </div>
 }
@@ -43,7 +31,7 @@ class FeaturePropertyPopup extends React.Component {
 
   render() {
     const features = this.props.features
-    return <div>
+    return <div className="maputnik-feature-property-popup">
       {features.map(renderFeature)}
     </div>
   }