Why does bootstrap only have 12 columns by default?

Bootstrapspinnersareusedtoindicateloadingstatesinwebapplications.1.Therearetwotypes:theborderspinner,whichrotates,andthegrowspinner,whichscaleswithapulsingeffect,bothrequiringrole="status"andavisuallyhidden"Loading..."messageforac

To add icons to the Bootstrap input box, you need to combine the input group and the icon library; 1. First introduce the icon library through CDN, such as BootstrapIcons or FontAwesome; 2. Use Bootstrap's input-group component to wrap the input box and add icons in the input-group-text; 3. If using BootstrapIcons, insert the icon; 4. The icon can be placed on the left or right side of the input box, the left side is used to prompt the input type, and the right side can be used to operate the button; 5. Support adding icons on both sides at the same time; ensure that the icon library is loaded correctly, and add aria-label to the key icons to improve accessibility, and ultimately achieve aesthetics and

To make Bootstrap's Scrollspy work properly with the fixed navigation bar, you must first make sure that the page structure contains chapters with ID and corresponding links. 1. Set the body's data-bs-spy="scroll", data-bs-target="#navbar" and data-bs-offset="70" to enable scrolling listening and correct offset; 2. Make sure that the ID of each content area exactly matches the href value of the navigation link; 3. Set padding-top for the body through CSS to avoid the content being blocked by fixed navigation; 4. Optionally use

UseacustomBootstrapbuildbyimportingonlynecessarySasscomponentstoreducefilesizeby50%ormore.2.MinifyCSSwithtoolslikecssnanoandremoveunusedclassesusingPurgeCSS,whilebeingcautiousofdynamicallyinjectedclasses.3.OptimizeCSSdeliverybyinliningcriticalstylesa

UseBootstrap’sgridandcardstostructurethetimelinewithalternatingleft-rightlayoutondesktopthatstacksonmobile.2.AddcustomCSStocreateacentralverticaltimelinelineandcircularmarkers,adjustingpositionformobileresponsiveness.3.Ensureaccessibilitywithsemantic

First, introduce the CSS and JS files of Bootstrap5, and use CDN links to quickly build the environment; 2. Create a product card grid, add the "QuickView" button to each card, and store the JSON string of product information through the data-product attribute; 3. Build the HTML structure of the model box, set the modal-lg class to obtain a larger display area, and use the Bootstrap grid system to realize the layout of pictures and details side by side; 4. Use JavaScript to listen to the show.bs.modal event, dynamically analyze the data-product data on the button and fill it into the corresponding elements of the modal box, real-time update of the content; 5. Optional enhancement

Bootstrap adopts a mobile-first design by default. The key to creating a mobile-first layout is to use its responsive grid system and breakpoint classes; 1. Use .container or .container-fluid to wrap content, and use .row and .col-classes to build the basic layout internally; 2. Set the default style for small screens (col-12 without prefixes, etc.), and then gradually enhance the display effect of the large screen through breakpoint classes such as col-md-, col-lg-, etc.; 3. Use navbar-expand-lg to cooperate with navbar-toggler to achieve mobile folding and large screen expansion; 4. Add img-fluid class to the picture to adapt to the size; 5. Use fs-, p-

Bootstrap's mesh system builds complex and responsive layouts by flexibly using nested, responsive classes, Flexbox tools and spacing utilities. 1. The grid is based on Flexbox, and uses d-flex, justify-content-, align-items- and other classes to achieve alignment and layout control; 2. Create multi-level layouts by nesting .row in .col, suitable for sidebar or card internal structure; 3. Use responsive classes such as xs, sm, md to define layout changes on different devices, and adjust the content order through order-*; 4. Combine g-4, mx-auto equal-spacing classes and auto-layout to achieve fine layout, and use w-10