Release Changelog

Production Performance Scorecard (Q4 2026)

Every release is rigorously benchmarked to maintain perfect technical performance and accessibility conformance:

Release Focus: 8-Dimension Tool Site Pre-Deployment Certification, LLM Search Optimization & Universal Absolute URL Enforcement

• Production Server Infrastructure (.htaccess): Deployed complete 10-rule Apache configuration enforcing HTTPS redirect, apex domain canonicalization, subdirectory trailing slash normalization, security headers (X-Frame-Options, X-Content-Type-Options, Referrer-Policy), Gzip/Deflate compression, and 1-year immutable caching for static assets.
• 14-Bot Crawler Architecture (robots.txt): Configured permissive access for major search engines and AI frontier crawlers (Googlebot, Bingbot, Applebot, GPTBot, ClaudeBot, PerplexityBot, Cohere, Meta, etc.) with explicit XML sitemap referencing.
• Indexable-Only Sitemap (sitemap.xml): Compiled clean XML sitemap with 80 indexable canonical tools and trust pages, strictly isolating non-indexable legal boilerplate (/privacy, /terms, 404.html).
• AI Search Optimization (llms.txt): Deployed 9-section LLM Knowledge Base specifying mathematical formulas, initial baseline modulus guards, client-side privacy architecture, and authoritative entity definitions with `` discovery links sitewide.
• 100% Absolute Asset Integrity: Upgraded all media elements, brand logos, creator portraits, and fallback handlers to fully qualified absolute URLs (https://percentagedecreasecalculator.com/...).
• Multi-Input Flexbox Ergonomics: Implemented flex: 1 1 0; min-width: 0; across multi-input calculators (Pie Chart, Ethnicity, Macro, and Audiobook) to eliminate browser-level intrinsic input overflow across all viewport widths.

Release Focus: Architecture Static Migration, Media Directory Isolation & Algorithmic Hardening

• Zero-Dependency Static Architecture: Completely migrated from dynamic server frameworks to pure Semantic HTML5, Vanilla CSS tokens, and optimized JavaScript engines with zero render-blocking libraries.
• Centralized Media Hub: Consolidated all graphical assets into the isolated /media/ directory with dual-path offline fallbacks (../media/ and /media/).
• Multi-Resolution Favicon Suite: Designed and deployed antialiased multi-tier favicon mipmaps (16px, 32px, 48px, 64px, 512px) featuring mathematical reduction indicators on emerald squircle.
• IEEE 754 Floating-Point Precision Guard: Integrated binary float normalization eliminating epsilon rounding drift on financial calculations (e.g., 0.3 - 0.2 = 0.1) via standard epsilon half-up rounding.
• Foundational Trust Suite: Deployed comprehensive E-E-A-T suite including About Us, Methodology & Math Standards, Accessibility Statement, Editorial Guidelines, Contact & Feedback, Privacy Policy, Terms of Service, and custom 404 Error Recovery.

Release Focus: Academic Performance & Evaluation Silo Expansion

• Academic & Evaluation Engine: Deployed 9 specialized calculators covering Reading Accuracy Rate, Vote Percentage, Absence Percentage, Attendance Percentage, Class Rank Percentage, Percentage to CGPA, CGPA to Percentage, Percentage to GPA, and GPA to Percentage.
• Multi-Scale Conversion Models: Added support for CBSE statutory 9.5 factor, standard 4.0 US scales, 5.0 honors scales, and Australian 7.0 collegiate scales.
• Full JSON-LD Graph Synchrony: Integrated complete schema graphs encompassing WebPage, WebApplication, BreadcrumbList, Person publisher metadata, and FAQPage accordions.
• Semantic Internal Linking Diversification: Implemented natural, varied, multi-word descriptive anchor texts across analytical sections (Section 1, 2, 4, 5, and 6), eliminating repetitive exact-match anchors while reinforcing topical co-occurrence.

Release Focus: Negative Baseline Modulus & Safari Decimal Input Polish

• Modulus Denominator Enforcement: Enforced absolute value rule |V_initial| across all change engines to prevent erroneous negative ratios when calculating relative deltas against negative baselines.
• Mobile Keypad Decimal Parsing: Added strict sanitation for iOS Safari soft-keypad numeric inputs, ensuring international comma decimal separators normalize smoothly to standard period points.
• Focus State Visibility: Enhanced WCAG focus rings on reset and calculation buttons with a 3px contrast outline.

Release Focus: Step-by-Step Educational Proofs & Directional Delta Inversion

• Step-by-Step Breakdown Container: Upgraded calculation output to render explicit algebraic fractions, substitution steps, decimal factors, and percentage multipliers for students and educators.
• Directional Delta Auto-Detection: Added automatic trajectory evaluation—if final value exceeds starting value, the engine transparently transitions to calculate percentage increase with distinct emerald green badges.
• Clear Button Ergonomics: Implemented single-click reset button clearing active inputs, step breakdowns, and restoring cursor focus to the primary input field.

Release Focus: Clipboard Feedback & High-DPI Rendering

• Modern Clipboard API Integration: Upgraded copy utility to async navigator.clipboard.writeText with fallback to legacy execCommand for older browser sandboxes.
• Visual Copied Feedback: Added temporary 2-second badge confirmation ("Copied!") preventing duplicate copy clicks.
• Vector SVG Icons: Replaced raster icons with lightweight inline vector SVG symbols for crisp rendering on high-DPI Retina screens.

Release Focus: WCAG 2.1 AA Accessibility & Mobile Keyboard Ergonomics

• ARIA Live Region Integration: Wrapped solution containers in aria-live="polite" so that screen readers immediately verbalize results upon execution without interrupting user workflow.
• Keyboard Enter-Key Bindings: Enabled instant calculation upon pressing Enter in any numeric input field.
• High-Contrast Color Tokens: Tuned all text contrast ratios to exceed 7:1 in body copy and 12:1 in footer sections on dark backgrounds.
• Anti-Flash Theme Toggle: Deployed synchronous inline IIFE in <head> preventing theme flashing during page transitions.

Release Focus: Thematic Silo Expansion & Financial Utilities

• Financial Silo Launch: Added specialized engines for Year-over-Year (YoY), Month-over-Month (MoM), equity dilution, and gross profit margin decline.
• Educational Silo Launch: Integrated grade decrease, GPA impact, and syllabus completion calculators.
• Semantic Breadcrumbs: Added microdata-backed schema breadcrumb navigation across all directory nodes.

Release Focus: 100% Client-Side Privacy Refactor & Offline Support

• Zero-Telemetry Engine: Removed all server-side calculation APIs. 100% of arithmetic runs locally in the browser's JavaScript sandbox.
• Zero Third-Party Tracking: Removed third-party tracking cookies, analytics pixels, and external font CDNs for total privacy and speed.
• Offline Computation: Once cached, tools execute without an active internet connection.

Release Focus: Zero-Baseline Validation & Fraction Notation

• Zero-Baseline Division Guard: Integrated explicit mathematical guard blocking undefined division when initial value is 0, providing contextual explanation to users.
• HTML Fraction Render Engine: Introduced clean typographic stacked fraction display (numerator over denominator) replacing ambiguous inline slash notation.

Release Focus: Input Sanitization & International Decimal Delimiters

• Regex Input Sanitizer: Added automatic filtering against non-numeric characters and accidental multiple decimal separators.
• Mobile Touch Optimization: Configured inputmode="decimal" on all number inputs to summon the appropriate numeric keyboard on mobile devices.

Release Focus: Initial Public Launch of Core Mathematical Calculators

• Flagship Calculator Launch: Initial deployment of Percentage Decrease Calculator by founder Jack Tyson.
• Basic Step Verification: Elementary solution display and clear input reset functionality.
• Responsive Layout: Flexbox grid foundation compatible across desktop and mobile screens.