170 cards
Every HTML5 page begins with a doctype declaration, written as `` on the very first line. This single line tells the browser to render the document in standards mode, following the HTML5 specification. Without it, browsers fall back to quirks mode, emulating legacy behaviors that break modern CSS layouts and box-model...
HTML5 dramatically expanded form capabilities beyond simple text and password fields. Modern input types include `email` and `url` for automatic format validation, `number` with built-in spinners, `range` for slider controls, `date`, `time`, and `datetime-local` for date and time entry, `color` for a native color picke...
CSS selectors are the foundation of styling, targeting HTML elements through several basic mechanisms. The element selector applies to every instance of a tag, the class selector targets any element carrying that class, the ID selector targets the single element with that ID, the universal selector (an asterisk) matche...
Every element in CSS is rendered as a rectangular box composed of four layers: the content itself (text or images), padding (space between the content and the border), the border that surrounds the padding, and margin (space outside the border separating the element from its neighbors). By default, the `width` and `hei...
Flexbox (Flexible Box Layout) is a one-dimensional layout model designed for distributing space and aligning items along a single direction, either a row or a column. It excels at centering elements both vertically and horizontally, building navigation bars, creating card layouts in a single row, and distributing space...
Responsive web design adapts layouts to the user's device, beginning with the viewport meta tag: ``. Without it, mobile browsers render the page at a desktop width (typically 980 pixels) and scale it down, which breaks responsive techniques entirely. The foundation of responsiveness is the media query, written as `@med...
CSS transitions animate property changes smoothly over time, defined with `transition: property duration timing-function delay`. When a listed property changes (for example, a button's background on hover), the browser interpolates the value across the duration using the specified timing function. Common functions incl...
Script loading behavior dramatically affects perceived performance. A stylesheet `` is render-blocking, because the browser pauses rendering until the CSS is fetched and parsed (otherwise unstyled content flashes badly), and a `` is parser-blocking by default, pausing parsing to fetch and execute before resuming. The `...