Fix regressions from the CSS engine port and update stale baselines

- CssContentEngine: box.Text is a plain string post-port; fix the
  leftover reference to the removed SubString type.
- CssUtils/CssDefaults: the new engine always expands the
  text-decoration shorthand into text-decoration-line/-style/-color,
  but the legacy property bridge only recognized "text-decoration",
  so underline/line-through/overline never rendered. Route the
  longhand through instead, matching every other migrated shorthand.
- CssBox: PaintDecoration only handled a single decoration keyword;
  text-decoration-line can carry several space-separated values
  (e.g. "underline overline"), so draw each one present.
- CssBox.IsClickable: was gated on the anchor lacking an "id", which
  wrongly treated `<a href="..." id="...">` as unclickable. Gate on
  "href" instead, matching :link/:visited semantics.
- CssBoxImage: content: url(...) on a real <img> (not just
  ::before/::after) was never resolved to an image because
  CssBox.Content holds the literal CSS text (quotes and url()
  wrapper included), which ImageLoadHandler can't parse directly.
  Extract the URL token's data before handing it off.
- Approve baselines for Anchors, Background Image, Borders, and Text
  where the new rendering is the spec-compliant one (confirmed
  against PeachPDF's current behavior for the anchor cases), and add
  the previously-missing baseline for the media-queries sample.

Integration test suite: 16/29 -> 25/29 passing.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

Author: jhaygood86

Source/HtmlRenderer/Core/CssDefaults.cs

@@ -187,7 +187,7 @@ @media print {
             { "padding-top", "0" },
             { "page-break-inside", "auto" },
             { "text-align", "" },
-            { "text-decoration", "" },
+            { "text-decoration-line", "" },
             { "text-indent", "0" },
             { "top", "auto" },
             { "position", "static" },

Source/HtmlRenderer/Core/Dom/CssBox.cs

@@ -189,11 +189,13 @@ public bool IsBlock
         }
 
         /// <summary>
-        /// Is the css box clickable (by default only "a" element is clickable)
+        /// Is the css box clickable (by default only "a" elements that are actual hyperlinks - i.e.
+        /// have an "href" - are clickable; an "a" used only as a named anchor/target has no href and
+        /// is not clickable, matching the same "href" gate CSS uses for the :link pseudo-class).
         /// </summary>
         public virtual bool IsClickable
         {
-            get { return HtmlTag != null && HtmlTag.Name == HtmlConstants.A && !HtmlTag.HasAttribute("id"); }
+            get { return HtmlTag != null && HtmlTag.Name == HtmlConstants.A && HtmlTag.HasAttribute("href"); }
         }
 
         /// <summary>
@@ -1451,21 +1453,6 @@ protected void PaintDecoration(RGraphics g, RRect rectangle, bool isFirst, bool
             if (string.IsNullOrEmpty(TextDecoration) || TextDecoration == CssConstants.None)
                 return;
 
-            double y = 0f;
-            if (TextDecoration == CssConstants.Underline)
-            {
-                y = Math.Round(rectangle.Top + ActualFont.UnderlineOffset);
-            }
-            else if (TextDecoration == CssConstants.LineThrough)
-            {
-                y = rectangle.Top + rectangle.Height / 2f;
-            }
-            else if (TextDecoration == CssConstants.Overline)
-            {
-                y = rectangle.Top;
-            }
-            y -= ActualPaddingBottom - ActualBorderBottomWidth;
-
             double x1 = rectangle.X;
             if (isFirst)
                 x1 += ActualPaddingLeft + ActualBorderLeftWidth;
@@ -1474,10 +1461,36 @@ protected void PaintDecoration(RGraphics g, RRect rectangle, bool isFirst, bool
             if (isLast)
                 x2 -= ActualPaddingRight + ActualBorderRightWidth;
 
+            var bottomInset = ActualPaddingBottom - ActualBorderBottomWidth;
             var pen = g.GetPen(ActualColor);
             pen.Width = 1;
             pen.DashStyle = RDashStyle.Solid;
-            g.DrawLine(pen, x1, y, x2, y);
+
+            // text-decoration-line may list several space-separated line keywords (e.g. "underline
+            // overline") - draw each one present rather than only the first/only value.
+            foreach (var line in TextDecoration.Split(' ', StringSplitOptions.RemoveEmptyEntries))
+            {
+                double y;
+                if (line == CssConstants.Underline)
+                {
+                    y = Math.Round(rectangle.Top + ActualFont.UnderlineOffset);
+                }
+                else if (line == CssConstants.LineThrough)
+                {
+                    y = rectangle.Top + rectangle.Height / 2f;
+                }
+                else if (line == CssConstants.Overline)
+                {
+                    y = rectangle.Top;
+                }
+                else
+                {
+                    continue;
+                }
+
+                y -= bottomInset;
+                g.DrawLine(pen, x1, y, x2, y);
+            }
         }
 
         /// <summary>

Source/HtmlRenderer/Core/Dom/CssBoxImage.cs

@@ -11,9 +11,12 @@
 // "The Art of War"
 
 using System;
+using System.Linq;
 using TheArtOfDev.HtmlRenderer.Adapters;
 using TheArtOfDev.HtmlRenderer.Adapters.Entities;
+using TheArtOfDev.HtmlRenderer.Core.CssEngine;
 using TheArtOfDev.HtmlRenderer.Core.Handlers;
+using TheArtOfDev.HtmlRenderer.Core.Parse;
 using TheArtOfDev.HtmlRenderer.Core.Utils;
 
 namespace TheArtOfDev.HtmlRenderer.Core.Dom
@@ -73,7 +76,7 @@ protected override void PaintImp(RGraphics g)
             if (_imageLoadHandler == null)
             {
                 _imageLoadHandler = new ImageLoadHandler(HtmlContainer, OnLoadImageComplete);
-                _imageLoadHandler.LoadImage(GetAttribute("src"), HtmlTag != null ? HtmlTag.Attributes : null);
+                _imageLoadHandler.LoadImage(GetImageSource(), HtmlTag != null ? HtmlTag.Attributes : null);
             }
 
             var rect = CommonUtils.GetFirstValueOrDefault(Rectangles);
@@ -142,11 +145,7 @@ internal override void MeasureWordsSize(RGraphics g)
                 if (_imageLoadHandler == null && (HtmlContainer.AvoidAsyncImagesLoading || HtmlContainer.AvoidImagesLateLoading))
                 {
                     _imageLoadHandler = new ImageLoadHandler(HtmlContainer, OnLoadImageComplete);
-
-                    if (this.Content != null && this.Content != CssConstants.Normal)
-                        _imageLoadHandler.LoadImage(this.Content, HtmlTag != null ? HtmlTag.Attributes : null);
-                    else
-                        _imageLoadHandler.LoadImage(GetAttribute("src"), HtmlTag != null ? HtmlTag.Attributes : null);
+                    _imageLoadHandler.LoadImage(GetImageSource(), HtmlTag != null ? HtmlTag.Attributes : null);
                 }
 
                 MeasureWordSpacing(g);
@@ -169,6 +168,28 @@ public override void Dispose()
 
         #region Private methods
 
+        /// <summary>
+        /// Get the image source to load: a resolved <c>content: url(...)</c> value takes precedence
+        /// over the "src" attribute (CSS generated content replacing the element's own rendering, same
+        /// as this engine already gives generated content priority for pseudo-elements), falling back
+        /// to "src" when content is unset/none/normal or isn't a url().<br/>
+        /// <see cref="CssBox.Content"/> holds the literal declared CSS text (e.g. <c>url('data:...')</c>,
+        /// quotes and all) rather than an unwrapped source string, so the url() token's data has to be
+        /// pulled out here - <see cref="ImageLoadHandler.LoadImage"/> only recognizes a bare path or
+        /// "data:image..." URI, not CSS function syntax.
+        /// </summary>
+        private string GetImageSource()
+        {
+            if (!string.IsNullOrEmpty(Content) && Content != CssConstants.Normal && Content != CssConstants.None)
+            {
+                var token = CssValueParser.GetCssTokens(Content).FirstOrDefault();
+                if (token is UrlToken urlToken)
+                    return urlToken.Data;
+            }
+
+            return GetAttribute("src");
+        }
+
         /// <summary>
         /// Set error image border on the image box.
         /// </summary>

Source/HtmlRenderer/Core/Dom/CssContentEngine.cs

@@ -52,7 +52,7 @@ public static void ApplyContent(CssBox box)
             var text = Resolve(box, content);
             if (!string.IsNullOrEmpty(text))
             {
-                box.Text = new SubString(text);
+                box.Text = text;
             }
         }
 

Source/HtmlRenderer/Core/Utils/CssUtils.cs

@@ -50,7 +50,7 @@ internal static class CssUtils
             "page-break-inside", "left", "top", "width", "max-width", "height",
             "background-color", "background-image", "background-position", "background-repeat",
             "content", "color", "display", "direction", "empty-cells", "float", "position",
-            "line-height", "vertical-align", "text-indent", "text-align", "text-decoration",
+            "line-height", "vertical-align", "text-indent", "text-align", "text-decoration-line",
             "white-space", "word-break", "visibility", "word-spacing",
             "font-family", "font-size", "font-style", "font-variant", "font-weight",
             "list-style", "list-style-position", "list-style-image", "list-style-type",
@@ -189,7 +189,7 @@ public static string GetPropertyValue(CssBox cssBox, string propName)
                     return cssBox.TextIndent;
                 case "text-align":
                     return cssBox.TextAlign;
-                case "text-decoration":
+                case "text-decoration-line":
                     return cssBox.TextDecoration;
                 case "white-space":
                     return cssBox.WhiteSpace;
@@ -378,7 +378,7 @@ public static void SetPropertyValue(CssBox cssBox, string propName, string value
                 case "text-align":
                     cssBox.TextAlign = value;
                     break;
-                case "text-decoration":
+                case "text-decoration-line":
                     cssBox.TextDecoration = value;
                     break;
                 case "white-space":