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Hướng dẫn, bài học và mẹo để tận dụng tối đa các công cụ trực tuyến miễn phí. 120 bài viết.
120 articles — page 2 of 5
Rounded Corners Are Not Just Aesthetic. Research Shows They Change How Users Perceive Content.
Rounded corners have measurable effects on perceived friendliness and approachability. Here is what perceptual research says and how CSS border-radius actually works.
The One CSS Property That Replaced Forty Image Slices
Before CSS box-shadow, web shadows required eight image slices and nested HTML. Here is how the property works, what its five parameters do, and when it hurts performance.
Bell Labs Built a Machine in 1952 That Recognized Ten Digits, Spoken by One Voice. The Gap Between Then and Now Is Hard to Overstate.
Trace speech recognition from Bell Labs' Audrey in 1952 through Hidden Markov Models, Dragon Dictate, and OpenAI Whisper. Seven decades of breakthroughs explained.
She Spent Three Hours on a YouTube Thumbnail. The Analytics Did Not Notice.
Learn why top creators study original thumbnail image files rather than screenshots, and what YouTube's stored resolutions reveal about what drives clicks.
What Actually Happens to a Font When PowerPoint Becomes a PDF
Font substitution in PDFs is silent and destructive. Learn how Type 1, TrueType, and OpenType fonts get embedded, subsetted, or dropped during PowerPoint export.
Every Platform Changed Its Image Dimensions in 2025. The Mistake Most People Make Is Still Aspect Ratio.
Platform algorithms crop images automatically to fit containers. Getting aspect ratio wrong loses subjects. Getting pixel dimensions wrong loses sharpness. Here is which matters more.
The Name That Feels Perfect Is Usually Already Trademarked. Here Is a Better Naming Process.
More trademarks have been filed in the last 25 years than the previous 60 combined. Here is how to run a naming process that starts with availability, not feeling.
She Had Four PNG Files and a Portal That Only Accepted PDF. Here Is What the Conversion Actually Does.
PNG is an image. PDF is a document. When a submission portal requires PDF, here is exactly what changes when you convert your PNG images and why document structure matters.
Income Is the Most Overrated Number in Personal Finance
Your salary tells you how much money arrives. Net worth tells you how much sticks. The gap between the two is where financial health lives.
A Professor in 1994 Discovered That the Nonsense Text Designers Use Comes from Cicero
In 1994, Richard McClintock traced Lorem Ipsum to Cicero's De Finibus. The placeholder text designers use comes from a scrambled 2,000-year-old philosophy book.
For Decades, Enlarging an Image Always Meant Losing Quality. Here Is How AI Changed That in 2014.
Traditional image enlargement guessed pixel values and introduced blur. A 2014 neural network paper changed the approach. Here is how AI upscaling works and its limits.
301 or 302, 401 or 403, 503 or 504: The Status Code Pairs Developers Choose Between Every Week
RFC 7231 replaced RFC 2616 partly because these pairs were misunderstood. Here is what each code actually signals to browsers, caches, and crawlers.
The Spreadsheet Was Clean and Well-Organized. The API Could Not Read It. Here Is Why.
Spreadsheets use CSV. APIs use JSON. Here is what happens during the conversion, what data type issues to watch for, and what to check before sending the result to an API.
Hourly or Salary: The Math Is Simple. The Right Choice Depends on Four Things the Offer Letter Does Not Say.
The choice between hourly and salary pay comes down to overtime eligibility, hours variability, and benefits. Here's how to compare them accurately.
Shigetaka Kurita Made 176 Emoji on a 12x12 Pixel Grid in 1999. There Are Now 3,600.
Shigetaka Kurita designed 176 emoji for NTT DoCoMo in 1999. They are now in MoMA. Unicode standardized emoji in 2010. Apple's iOS keyboard in 2011 drove global adoption.
A CSS Gradient Is Not an Image. Here Is What the Browser Is Actually Rendering.
CSS gradients are generated images calculated at render time, not files. Here is how linear, radial, and conic gradients work, and why color interpolation space matters.
Clothing Sizes Are Not Measurements. The Numbers Have Been Getting Smaller on Purpose Since 1983.
A 1937 size 14 dress is now labeled a size 0. The US dropped its clothing size standard in 1983. Here's why the numbers are labels, not measurements.
The Recipe Says Two Cups. The Australian Cup and the American Cup Are Not the Same Volume.
A US cup is 236.6 ml. An Australian metric cup is 250 ml. The difference is nearly a tablespoon — enough to change texture in precision baking.
The %20 in Your URL Is Not a Bug. It Is a Rule From 1994 That Most Developers Apply Wrong.
Percent-encoding was formalized in RFC 1738 in 1994. Spaces become %20, but encoding an entire URL at once breaks it. Here is the correct and incorrect way to encode URLs.
Remote Work Did Not Remove Geographic Constraints. It Replaced Them With Temporal Ones.
The real challenge of global remote teams is not scheduling — it is overlap. A world clock makes the available shared hours immediately visible.
The Shoe Size Number on Your Tag Traces to a Grain of Barley from 1324
King Edward II standardized the barleycorn in 1324. That same unit still determines US and UK shoe sizes today, and it explains why three global systems are incompatible.
When Sending a JPG Is the Right Move (and PDF Is Actually Wrong)
PDF and JPEG are not competing formats. Here's when converting a PDF page to JPG is the technically correct choice for social media, inline display, and image workflows.
Computers Cannot Generate Random Numbers. What They Actually Produce Is Usually Good Enough Anyway.
Every computer algorithm that produces 'random' numbers is deterministic. RAND published a book of genuine random digits in 1955. Here's why the distinction matters for security but not for raffles.
Most Courts Now Mandate Text-Searchable PDFs. Here Is What Happens When You Submit a Scanned Document Instead.
California Rule 8.74 and federal courts require text-searchable PDFs. Learn what happens when you submit an image-only scanned document and how OCR fixes it.