Changing header banner dimension in child theme

Problem solved. 

.site-header {
    background: url(<?php header_image(); ?>) no-repeat scroll top;
    background-size: 900px auto!important;
}

Related Posts:

  1. How to add code to Header.php in a child theme?
  2. How to override JavaScript files in child theme?
  3. Versioning @import of parent theme’s style.css
  4. Why does my child theme CSS get called twice?
  5. How do themes provide support for child themes?
  6. Attributing a version number to a child theme’s main stylesheet
  7. Preserving theme settings in child theme
  8. Is it possible to make grandchild themes?
  9. how do I queue my Child stylesheet/s *after* every Parent stylesheet/statement?
  10. How to cache bust a child theme style.css
  11. Adding javascript to child theme
  12. Is a text-domain necessary for a child theme
  13. How to modify single.php in a child theme?
  14. Cannot get Child Theme to load latest version of style.css
  15. Issues enqueueing parent & child theme stylesheets with revised Codex method
  16. @package & @subpackage: how to use with child themes
  17. How to override function in child theme
  18. Why is the Child Theme Stylesheet Not Loading?
  19. Hiding Parent Theme
  20. get_stylesheet_directory() vs get_template_directory() for child theme
  21. Theme Customization API and child themes
  22. get_parent_theme_file_path vs. get_template_directory
  23. Git vs Child Theme
  24. Give priority to child theme stylesheet
  25. Child theme does not overwrite parent themes style.css
  26. how to call files in child theme?
  27. Get Parent Theme Author Name
  28. Get parent theme version
  29. Optimal approach for replacing the 8 header images in a child theme?
  30. How to transfer changes to a child theme?
  31. WordPress master + child themes + Git workflow
  32. How to use parent theme’s enqueue methods
  33. How do I override a parent theme’s language files with a child theme?
  34. something like is_childtheme()
  35. Do all files in child theme override the parent?
  36. Child theme showing a blank page
  37. Child theme preview missing
  38. Child Theme Performance
  39. How could child theme be different than parent theme if I haven’t made changes?
  40. How to solve “Warning: Use of undefined constant” when overriding a parent theme function in the child theme?
  41. Do I need to update the child theme too after updating the parent?
  42. get_template_directory vs get_stylesheet_directory
  43. Theme customizer: How do you grab the value later?
  44. Developing a childtheme, how to disable the parents templates?
  45. Under heavy cache conditions, updating the parent theme don’t reflect changes with child theme enabled
  46. How to maintain wp_enqueue_style dependencies set in parent theme style enqueuing
  47. Child Theme, Functions.php Issues
  48. Redefining function in child themes
  49. How do I check for child theme files first using include, before going to parent theme?
  50. How can you change default color scheme in a Twenty Fifteen child theme?
  51. Use admin options from parent theme in child theme
  52. When activating a child theme, what core settings have to be reset ie; Custom Menus etc?
  53. Hwo to turn off “get_parent_theme_file_path” in child-theme?
  54. Overriding parent theme file
  55. How to “remove” file from parent theme
  56. How to override the Parent theme Function into child themes functions.php
  57. How can I make new .css file in child theme override styles in child theme’s style.css
  58. Enqueue styles properly in a child theme and stylesheets location
  59. Enqueue more than two CSS styles in a child theme functions.php
  60. Proper way to make a tweaked theme into child-theme setting?
  61. Promoting child theme to stand alone
  62. How to disable updates in WordPress theme
  63. Style.css in child theme is loaded before Bootstrap
  64. Activating child theme returns “active theme is broken”
  65. Overiding functions.php with child-theme
  66. How are updates to the style.css file in child theme recognized?
  67. How do I set up a child-theme without using @import
  68. Find a Parent Theme’s stylesheet $handle when it registers a stylesheet
  69. Child theme error “Template is missing”
  70. Dequeue only stylesheets but not inline style added using wp_add_inline_style
  71. How to change default header image dimensions in twentyfourteen child theme?
  72. Overwrite CSS with without deleting it
  73. Adding or modifying in files of parent theme via child’s function.php
  74. Enqueue stylesheets if parent theme has more than one .css file
  75. replace parent theme images in child theme
  76. Website Broken on Activating Child Theme! [closed]
  77. Child theme implementation issues
  78. Can’t override footer.php in child theme
  79. Child themes & updates?
  80. Add post dates from child theme and change font size on homepage post
  81. Recommended way to load / enqueue parent and child stylesheet to enable cache busting
  82. Altered media sizes (in dash), not updating to existing images/posts
  83. How do I make wp_localize_script variables available for child theme?
  84. HTML head-tag get broken in my child theme
  85. iPhone Safari full size & PC versions different
  86. Where to put custom PHP files in a child theme?
  87. Where is wp-content/themes folder?
  88. How can I override file featured-image-first.php of Avada theme [closed]
  89. Child Theme Path Being Ignored With wp_enqueue_scripts
  90. Why is “get_template_directory_uri” pointing to child theme?
  91. ERROR MESSAGE: Missing index.php—Child Theme
  92. How to make child theme ignore a parent themes template
  93. Conditionally load child themes
  94. Child theme undefined variable error
  95. get_theme_mod is returning a number rather than my image file
  96. Priority loading file css in child theme
  97. Is my child theme working properly
  98. WP .js script file not loading
  99. Enqueue Child CSS to Load After Bootstrap CDN
  100. Child theme style repeated