chore: release v5.5.3

- Bump version from 5.5.3-b2 to 5.5.3 in package.json
- Update third-party dependencies:
  * algolia_search: 5.43.0 -> 5.46.0
  * docsearch: 4.3.1 -> 4.3.2
  * fancybox: 6.1.4 -> 6.1.7
  * katex: 0.16.25 -> 0.16.27
  * mermaid: 11.12.1 -> 11.12.2
  * waline: 3.7.1 -> 3.8.0

perf: optimize JavaScript performance
- Add defer attribute to script tags in pjax and prismjs
- Improve DOM content loading timing in pjax
- Optimize utilities with better throttle implementation
- Cache header positions for TOC performance
- Optimize related posts generation with Maps
- Improve archive helpers performance

fix: improve error handling and UI fixes
- Replace process.exit with proper error throwing
- Fix tooltip positioning with boundary checks
- Add btn-effects to readmode exit button
- Fix element height calculation for hidden elements
- Improve image filters in dark mode (brightness .88, contrast .95)

style: code improvements and consistency
- Refactor random cover generation with generator pattern
- Optimize data processing in helpers
- Clean up unused functions and improve code structure
- Fix Chinese translation: 页 -> 頁

source/css/_mode/darkmode.styl

@@ -141,9 +141,9 @@ if hexo-config('darkmode.enable') || hexo-config('display_mode') == 'dark'
 
     img:not(.cover)
       if hexo-config('lazyload.enable') && hexo-config('lazyload.blur') && !hexo-config('lazyload.placeholder')
-        filter: blur(0) brightness(.8)
+        filter: blur(0) brightness(.88) contrast(.95)
       else
-        filter: brightness(.8)
+        filter: brightness(.88) contrast(.95)
 
     #aside-content .aside-list > .aside-list-item:not(:last-child)
       border-bottom: 1px dashed alpha(#FFFFFF, .1)

source/css/_mode/readmode.styl

@@ -42,6 +42,7 @@ if hexo-config('readmode')
       font-size: 16px
       transition: background .3s
       addBorderRadius(8)
+      @extend .btn-effects
 
       +maxWidth768()
         top: initial

source/js/main.js

@@ -84,7 +84,11 @@ document.addEventListener('DOMContentLoaded', () => {
         const buttonRect = ele.getBoundingClientRect()
         const scrollTop = window.pageYOffset || document.documentElement.scrollTop
         const scrollLeft = window.pageXOffset || document.documentElement.scrollLeft
-        const finalLeft = buttonRect.left + scrollLeft + buttonRect.width / 2
+
+        // X-axis boundary check
+        const halfWidth = newEle.offsetWidth / 2
+        const centerLeft = buttonRect.left + scrollLeft + buttonRect.width / 2
+        const finalLeft = Math.max(halfWidth + 10, Math.min(window.innerWidth - halfWidth - 10, centerLeft))
 
         // Show tooltip below button if too close to top
         const normalTop = buttonRect.top + scrollTop - 40
@@ -159,6 +163,7 @@ document.addEventListener('DOMContentLoaded', () => {
 
     // 獲取隱藏狀態下元素的真實高度
     const getActualHeight = item => {
+      if (item.offsetHeight > 0) return item.offsetHeight
       const hiddenElements = new Map()
 
       const fix = () => {
@@ -545,17 +550,29 @@ document.addEventListener('DOMContentLoaded', () => {
     const $articleList = $article.querySelectorAll('h1,h2,h3,h4,h5,h6')
     let detectItem = ''
 
+    // Optimization: Cache header positions
+    let headerList = []
+    const updateHeaderPositions = () => {
+      headerList = Array.from($articleList).map(ele => ({
+        ele,
+        top: btf.getEleTop(ele),
+        id: ele.id
+      }))
+    }
+
+    updateHeaderPositions()
+    btf.addEventListenerPjax(window, 'resize', btf.throttle(updateHeaderPositions, 200))
+
     const findHeadPosition = top => {
       if (top === 0) return false
 
       let currentId = ''
       let currentIndex = ''
 
-      for (let i = 0; i < $articleList.length; i++) {
-        const ele = $articleList[i]
-        if (top > btf.getEleTop(ele) - 80) {
-          const id = ele.id
-          currentId = id ? '#' + encodeURI(id) : ''
+      for (let i = 0; i < headerList.length; i++) {
+        const item = headerList[i]
+        if (top > item.top - 80) {
+          currentId = item.id ? '#' + encodeURI(item.id) : ''
           currentIndex = i
         } else {
           break
@@ -633,7 +650,8 @@ document.addEventListener('DOMContentLoaded', () => {
 
       $body.classList.add('read-mode')
       newEle.type = 'button'
-      newEle.className = 'fas fa-sign-out-alt exit-readmode'
+      newEle.className = 'exit-readmode'
+      newEle.innerHTML = '<i class="fas fa-sign-out-alt"></i>'
       newEle.addEventListener('click', exitReadMode)
       $body.appendChild(newEle)
     },

source/js/utils.js

@@ -14,37 +14,35 @@
       }
     },
 
-    throttle: function (func, wait, options = {}) {
-      let timeout, context, args
+    throttle: (func, wait, options = {}) => {
+      let timeout, args
       let previous = 0
 
       const later = () => {
         previous = options.leading === false ? 0 : new Date().getTime()
         timeout = null
-        func.apply(context, args)
-        if (!timeout) context = args = null
+        func(...args)
+        if (!timeout) args = null
       }
 
-      const throttled = (...params) => {
+      return (...params) => {
         const now = new Date().getTime()
         if (!previous && options.leading === false) previous = now
         const remaining = wait - (now - previous)
-        context = this
         args = params
+
         if (remaining <= 0 || remaining > wait) {
           if (timeout) {
             clearTimeout(timeout)
             timeout = null
           }
           previous = now
-          func.apply(context, args)
-          if (!timeout) context = args = null
+          func(...args)
+          if (!timeout) args = null
         } else if (!timeout && options.trailing !== false) {
           timeout = setTimeout(later, remaining)
         }
       }
-
-      return throttled
     },
 
     overflowPaddingR: {
@@ -169,17 +167,7 @@
 
     isHidden: ele => ele.offsetHeight === 0 && ele.offsetWidth === 0,
 
-    getEleTop: ele => {
-      let actualTop = ele.offsetTop
-      let current = ele.offsetParent
-
-      while (current !== null) {
-        actualTop += current.offsetTop
-        current = current.offsetParent
-      }
-
-      return actualTop
-    },
+    getEleTop: ele => ele.getBoundingClientRect().top + window.scrollY,
 
     loadLightbox: ele => {
       const service = GLOBAL_CONFIG.lightbox
@@ -190,7 +178,7 @@
       }
 
       if (service === 'fancybox') {
-        Array.from(ele).forEach(i => {
+        ele.forEach(i => {
           if (i.parentNode.tagName !== 'A') {
             const dataSrc = i.dataset.lazySrc || i.src
             const dataCaption = i.title || i.alt || ''