style: improve documentation subsection (H3/H4) aesthetics

Author: Zuhaitz-dev

site/templates/base.html

@@ -453,6 +453,26 @@
             padding-bottom: 0.5rem;
         }
 
+        .doc-content h3 {
+            font-size: 1.25rem;
+            margin-top: 3.5rem;
+            margin-bottom: 1.5rem;
+            padding: 0.75rem 1rem;
+            background: #fcfaf6;
+            border-left: 4px solid var(--muted);
+            border-radius: 0 8px 8px 0;
+            color: var(--primary);
+            font-weight: 800;
+        }
+
+        .doc-content h4 {
+            font-size: 1.1rem;
+            margin-top: 2.5rem;
+            margin-bottom: 1rem;
+            font-weight: 700;
+            color: var(--secondary);
+        }
+
         .doc-content p {
             margin-bottom: 1.5rem;
             color: var(--muted);
@@ -865,6 +885,11 @@
             background: linear-gradient(90deg, rgba(255, 255, 255, 0.04), transparent);
         }
 
+        [data-theme="dark"] .doc-content h3 {
+            background: #1a1916;
+            border-left-color: #475569;
+        }
+
         [data-theme="dark"] .doc-content code {
             background: transparent;
         }
@@ -1213,7 +1238,7 @@
 
             {% if lang != "zh-cn" and lang != "zh-tw" %}
             <div class="search-container">
-                <input type="text" id="search" class="search-input" placeholder="{{ trans(key="search-placeholder",
+                <input type="text" id="search" class="search-input" placeholder="{{ trans(key=" search-placeholder",
                     lang=lang) }}" autocomplete="off">
                 <div class="search-results" id="search-results"></div>
             </div>