feat(frontend): align single post page 1:1 with Zibll

Restore Zibll float dual-column shell, fix single settings DTO key mapping,
reorder article footer/actions, and match author bar, prev/next, title/body
typography, and limit-height expand UX.

assets/js/page-template.js

@@ -190,15 +190,27 @@
   }
 
   function initContentExpand() {
-    document.querySelectorAll('.entry-content[data-nav]').forEach(function (content) {
+    // Zibll-style: inject .read-more inside .limit-height and expand on click.
+    document.querySelectorAll('.wp-posts-content.limit-height, .limit-height[data-nav]').forEach(function (content) {
       if (content.dataset.aksrtExpandBound === '1') return;
       content.dataset.aksrtExpandBound = '1';
 
-      // Only expand when server enabled maxheight (data-maxheight > 0).
       var customMax = parseInt(content.getAttribute('data-maxheight') || content.dataset.maxheight || '0', 10);
-      if (!(customMax > 0)) return;
-      var limit = customMax;
-      if (content.scrollHeight <= limit) {
+      // data-maxheight may be maxheight-80 (Zibll) or absolute maxheight; prefer style max-height.
+      var styleMax = 0;
+      if (content.style && content.style.maxHeight) {
+        styleMax = parseInt(content.style.maxHeight, 10) || 0;
+      }
+      var limit = styleMax > 0 ? styleMax : (customMax > 0 ? customMax + 80 : 0);
+      if (!(limit > 0) && customMax > 0) {
+        limit = customMax;
+      }
+      if (!(limit > 0)) {
+        content.classList.remove('limit-height');
+        return;
+      }
+
+      if (content.scrollHeight <= limit + 40) {
         content.classList.remove('limit-height');
         content.style.maxHeight = '';
         return;
@@ -207,37 +219,37 @@
       content.classList.add('limit-height');
       content.style.maxHeight = limit + 'px';
 
-      var existingBtn = content.nextElementSibling;
-      if (existingBtn && existingBtn.classList && existingBtn.classList.contains('content-expand-btn')) {
-        return;
-      }
+      if (content.querySelector('.read-more')) return;
 
-      var button = document.createElement('button');
-      button.type = 'button';
-      button.className = 'content-expand-btn';
-      button.innerHTML = '<i class="fas fa-chevron-down" aria-hidden="true"></i> <span>展开阅读全文</span>';
-      content.parentNode.insertBefore(button, content.nextSibling);
+      var wrap = document.createElement('div');
+      wrap.className = 'read-more';
+      var link = document.createElement('a');
+      link.href = 'javascript:;';
+      link.className = 'read-more-open';
+      link.innerHTML = '展开阅读全文<i class="fa ml10 fa-angle-down" aria-hidden="true"></i>';
+      wrap.appendChild(link);
+      content.appendChild(wrap);
 
-      button.addEventListener('click', function () {
-        var expanded = content.classList.contains('is-expanded');
-        if (expanded) {
-          content.classList.remove('is-expanded');
-          content.style.maxHeight = limit + 'px';
-          button.classList.remove('is-expanded');
-          button.querySelector('span').textContent = '展开阅读全文';
-          content.scrollIntoView({
-            behavior: 'smooth',
-            block: 'start'
-          });
-          return;
-        }
-
-        content.classList.add('is-expanded');
-        content.style.maxHeight = content.scrollHeight + 'px';
-        button.classList.add('is-expanded');
-        button.querySelector('span').textContent = '收起';
+      link.addEventListener('click', function (event) {
+        event.preventDefault();
+        content.classList.remove('limit-height');
+        content.style.maxHeight = '';
+        wrap.remove();
       });
     });
+
+    // Compatibility: old external expand buttons.
+    document.addEventListener('click', function (event) {
+      var open = event.target.closest && event.target.closest('.read-more-open');
+      if (!open) return;
+      var limitBox = open.closest('.limit-height');
+      if (!limitBox) return;
+      event.preventDefault();
+      limitBox.classList.remove('limit-height');
+      limitBox.style.maxHeight = '';
+      var more = open.closest('.read-more');
+      if (more) more.remove();
+    });
   }
 
   function initFlashQueryCleanup() {