Sounds like your are not creating a proper WordPress template when you copy your index.php.
Here you can find the list of standard template files: https://codex.wordpress.org/Theme_Development#id=%22Template_Files_List%22
And here you can learn how to create a custom template:
https://codex.wordpress.org/Theme_Development#Custom_Page_Templates
My guess is you need to add the following to the top of your index copy. Then make sure to select this template from the edit post/page view to use it on the front end (it should use the css).
<?php
/*
Template Name: Index Copy
*/
Related Posts:
- Where are Additional CSS files stored
- Show a WP 3.0 Custom Menu in an HTML Select with Auto-Navigation?
- FireFox Inspector :: find CSS file related to
- Cannot figure out how to center div in WordPress theme [closed]
- how can I change the background color of all posts on my server?
- Putting tag outside tag on generated Menu
- Navigation label for page in custom theme
- How to customize the WordPress 2014 theme, to have page using less horizontal margin?
- How to have multiple WordPress Menus
- WordPress menu: How to make www.link.com/#name never contain current_page_item class?
- Custom CSS Nav Menu Style Not Being Applied
- How replace theme styles?
- How do I target this page specifically?
- How do I change the content of an element for a theme without losing the styling?
- Remove wrapping div and ul from output of wp_nav_menu
- Customizing a WordPress theme without changing it?
- Prevent WordPress from automatically installing a new theme each year
- Is there a blank theme framework compatible with WP 3.0? [closed]
- How do register_sidebar() and get_sidebar() work together?
- How to include own css on wordpress tinymce editor?
- how to override woocommerce specific loop or archive-product.php [closed]
- Looking for a lightweight theme using WP3 new tags and features (not 2010) [closed]
- How to customize the default HTML for WordPress Attachments
- Add custom html to last sub-menu item
- Any official way to create an admin theme?
- Is it possible to change the attributes of a registered style or script before it fires?
- switch theme on fly
- wp_nav_menu() custom container and container_id
- global menus made from master site’s custom menus wpmu network
- 2 seperate installation 1 theme same server
- Widgets vs. Theme Mods
- Adding Custom Link anchors in the top menu that points to specific sections of the site home page
- wordpress custom walker for thumbnails with custom menu
- get_theme_mod(); returns nothing
- Custom CSS for full post vs. excerpt (Content Options)
- Create a customizable child theme
- Are there any ‘Coming Soon’ themes for WordPress 3.0?
- Make page template that is just an “include” of another?
- Show attribute description when filtering by that attribute
- Change default status and replace the icon for an hamburger menu
- simple expandable vertical menu, java script problem
- Create a Custom menu item fetched by Product Categories and Sub Categories
- How to highlight the current page in the nav menu?
- How to get WordPress to accept the tag in articles (or other alternatives)
- wp_nav_menu google analytics event tracking
- How can I & how do I change text displayed in comment via child theme
- Only append custom classes to nav menu items
- Add nav menu CSS class to body
- How to extend nav-menu-item-control data in Appearance > Customize?
- Hide Login information in Account settings in Buddy Boss
- How do I copy all “extra” data (menus, widgets, etc) from one theme to another?
- Where is definied the theme location for the main menu in a WordPress template?
- How to remove padding and margin between divi rows? [closed]
- How can I get the page url slug when ‘post_name’ returns an id?
- What will happen to the additional CSS when the theme is updated?
- woocommerce Add custom field set like billing fields
- How to display post title & excerpt when mouse hovers on an image?
- $wp_customize->remove_section for customizer setting?
- Include user defined styles without including wp-load
- remove everything from wp_nav_menu
- Modify a theme to insert custom widgets?
- ‘Customize’ button in admin bar for CSS
- Customizing default Mediaelement player
- Adding all sub-pages to the menu manager
- add JS to multiple plugin admin pages
- How to add “Read More…” link in twentytwenty
- Updating Existed RocketTheme Theme on WordPress
- CSS to remove “comments count” icon from main page [closed]
- title, content, feature images
- Get page ID outside the loop, matching menu ID
- how to add custom css and js on wordpress post editor directly without using .php file
- How to customize core admin pages within a theme?
- Programmatically (PHP) get the nr. of items in the primary navigation menu
- TwentyFifteen: How can it show a different color on every post page?
- Warning: Creating default object… when altering Customize panels
- How to make theme elements customizable in wordpress?
- Theme licensing and permission on changing content [closed]
- @font-face is not working in WordPress
- How to find out if page_for_posts is showing (in order to style menu item)
- What changes we need to make to a theme so it can be installed as a MU Theme?
- Updates for a private theme
- Adding code to child’s theme css and php cannot override certain elements
- How to create left and right menu with logo center in a custom theme?
- How to add custom page attributes in WordPress?
- Add clickable arrows to parent menu items with children elements e.g. with
- How Do I Remove The Right Hand Block On The Main Header?
- Is it possible to add a ribbon in the background of h1 on every page?
- custom theme ,add media not showing images in media library
- Resizing of a header/div in a website through css in wordpress [closed]
- Adding posts to custom menu [closed]
- How to wrap the list with custom class using wp_nav_menu?
- Alphabetical Custom Menu
- Theme Customization through admin panel. (Appearance-Customize)
- For a specific theme, how do I build a list of all the possible theme modification names?
- Child Theme with multiple css files
- Sub menu indicator that links to sub menu
- Different logo on homepage
- CSS Customizations for certain page
- Redirect to another page using contact form 7? [closed]
- WPML Plugin Not displaying multilingual Menus