# Contrast Detection Fixes

## Problems

The contrast checking tool had three issues that caused false positives and incorrect reporting:

### Issue 1: White-on-White False Positives
**Example:** Vision Leadership sponsor page (https://visionleadership.org/sponsor-opportunities/)
- **Reported:** White text `rgb(255, 255, 255)` on white background `rgb(255, 255, 255)` = 1:1 ratio (FAIL)
- **Reality:** White text on gradient background `linear-gradient(rgb(12, 90, 201) 0%, rgb(0, 0, 0) 100%)`
- **Actual Contrast:** 6.32:1 to 21:1 (PASS)

**Root Cause:** The gradient was on a parent container (`.et_pb_section`), not directly on the text elements. The tool only checked the element itself for gradients, not parent elements.

### Issue 2: Gradient Applied to Wrong Elements
After the initial fix, the tool became too aggressive:
- **Reported:** 54 elements with blue background `rgb(12, 90, 201)` (from gradient)
- **Reality:** Those elements were on light gray `rgb(252, 252, 252)` background
- **Root Cause:** Gradient detection walked up the tree but didn't stop when it encountered solid backgrounds

### Issue 3: Wrong Text Color for Elements with Child Spans
The tool used parent element colors instead of actual visible text colors:
- **Example:** `<a style="color: rgb(12, 113, 195)"><span style="color: #ffffff;">314-560-7171</span><br></a>`
- **Reported:** Used the `<a>`'s color (blue rgb(12, 113, 195)) = 4.17:1 contrast
- **Reality:** The visible text uses the `<span>`'s color (white rgb(255, 255, 255)) = 21.00:1 contrast
- **Root Cause:** Tool only checked the matched element's color, not descendant elements that contain the actual text

## Solutions

Modified the contrast detection logic in `daemon/daemon.go` to:

1. **Walk up the DOM tree** to find gradient backgrounds on parent elements
2. **Stop at solid backgrounds** - if a solid background color is found before a gradient, use the solid color
3. **Only apply gradients** when no solid background exists between the element and the gradient
4. **Check child elements for text color** - if an element has visible child elements with text, use the first child's color instead of the parent's color

### Code Changes

#### 1. Enhanced `analyzeGradientContrast` Function (Lines 9152-9220)

**Before:** Only checked the element itself for gradients

**After:** 
- Walks up the DOM tree looking for gradients
- Checks for solid backgrounds at each level
- Returns `null` if a solid background is found (gradient doesn't apply)
- Only returns gradient info if no solid background blocks it

```javascript
function analyzeGradientContrast(element, textColor) {
    let current = element;
    while (current && current !== document.documentElement.parentElement) {
        const style = window.getComputedStyle(current);
        
        // Check for solid background first - if found, gradient doesn't apply
        const bgColor = style.backgroundColor;
        if (!isTransparent(bgColor)) {
            return null; // Solid background found
        }

        // Check for gradient
        const bgImage = style.backgroundImage;
        if (bgImage && bgImage.includes('gradient')) {
            // Extract and analyze gradient colors...
            return gradientInfo;
        }

        current = current.parentElement;
    }
    return null;
}
```

#### 2. Updated Background Detection Logic (Lines 9305-9340)

**Before:** Always checked for gradients, even when solid backgrounds were found

**After:**
- Tier 1: Check for solid backgrounds via DOM tree walking
- Tier 2: Check for solid backgrounds via stacking context
- Tier 3: Only check for gradients if no solid background found
- Fallback: Use white if nothing found

```javascript
// Tier 1: DOM tree walking for solid colors
bgColor = getEffectiveBackgroundDOMTree(element);

// Tier 2: Stacking context analysis (if Tier 1 failed)
if (!bgColor) {
    bgColor = getBackgroundFromStackingContext(element);
}

// Tier 3: Check for gradients (only if no solid color found)
if (!bgColor) {
    gradientInfo = analyzeGradientContrast(element, fgColor);
    if (gradientInfo) {
        bgColor = gradientInfo.colors[0];
    }
}

// Fallback to white
if (!bgColor) {
    bgColor = 'rgb(255, 255, 255)';
}
```

## Testing

After deploying the fix, test on:

1. **Vision Leadership sponsor page** - Should correctly detect gradient and report passing contrast
2. **Elements with solid backgrounds** - Should not incorrectly apply gradients from parent containers
3. **Nested backgrounds** - Should use the closest background (solid or gradient)

## Expected Results

### Vision Leadership Hero Section
- **H1 "Sponsorship Opportunities That Work For You"**
  - Detection method: `gradient-analysis`
  - Gradient colors: `rgb(12, 90, 201)` to `rgb(0, 0, 0)`
  - Worst contrast: 6.32:1 (PASS AA for large text)
  - Best contrast: 21:1 (PASS AAA)

### Elements with Solid Backgrounds
- **Text on light gray `rgb(252, 252, 252)`**
  - Detection method: `dom-tree` or `stacking-context`
  - Should NOT use gradient from parent
  - Should calculate contrast against actual gray background

## Deployment

1. Build the daemon: `make daemon`
2. Build the MCP server: `make mcp`
3. Restart the cremote daemon (deployment-specific process)
4. Restart the MCP server or Augment extension to pick up changes

#### 3. Enhanced Text Color Detection (Lines 9301-9354)

**Before:** Always used the matched element's text color

**After:**
- Recursively searches all descendant elements to find the one with the most text content
- Uses that element's color for contrast checking
- Handles complex structures like `<a><span>text</span><br></a>`
- Skips invisible elements (display: none, visibility: hidden)

```javascript
// Recursively find the element with the most text content
function findTextBearingElement(el) {
    const descendants = el.querySelectorAll('*');
    let bestElement = el;
    let maxTextLength = 0;

    // Check the element itself first
    const directText = Array.from(el.childNodes)
        .filter(node => node.nodeType === Node.TEXT_NODE)
        .map(node => node.textContent.trim())
        .join('').length;

    if (directText > maxTextLength) {
        maxTextLength = directText;
        bestElement = el;
    }

    // Check all descendants
    for (const desc of descendants) {
        const descStyle = window.getComputedStyle(desc);
        if (descStyle.display === 'none' || descStyle.visibility === 'hidden') {
            continue;
        }

        const descText = Array.from(desc.childNodes)
            .filter(node => node.nodeType === Node.TEXT_NODE)
            .map(node => node.textContent.trim())
            .join('').length;

        if (descText > maxTextLength) {
            maxTextLength = descText;
            bestElement = desc;
        }
    }

    return bestElement;
}

// Find the element with the most text content
textElement = findTextBearingElement(element);
textStyle = window.getComputedStyle(textElement);
const fgColor = textStyle.color;
```

## Files Modified

- `daemon/daemon.go` - Lines 9152-9220 (gradient analysis function)
- `daemon/daemon.go` - Lines 9305-9340 (background detection logic)
- `daemon/daemon.go` - Lines 9301-9354 (text color detection enhancement with recursive search)