web-api: add clear button (x) to domain input field

router/route-web-api.py

@@ -641,8 +641,14 @@ HTML_PAGE = """\
   .health-gw .loss { color: #999; margin-left: 4px; }
   .content { flex: 1; min-width: 0; }
   .input-row { display: flex; gap: 8px; margin-bottom: 20px; }
-  .input-row input { flex: 1; padding: 8px 12px; border: 1px solid #ccc;
+  .input-wrap { position: relative; flex: 1; }
+  .input-row input { width: 100%; padding: 8px 30px 8px 12px; border: 1px solid #ccc;
                      border-radius: 4px; font-size: 1em; }
+  .clear-btn { position: absolute; right: 8px; top: 50%; transform: translateY(-50%);
+               background: none; border: none; color: #999; font-size: 1.2em;
+               cursor: pointer; padding: 0 4px; line-height: 1; display: none; }
+  .clear-btn:hover { color: #333; }
+  .clear-btn { color: #999 !important; background: none !important; padding: 0 4px !important; }
   .input-row input:focus { outline: none; border-color: #4a90d9; }
   button { padding: 8px 16px; border: none; border-radius: 4px; cursor: pointer;
            font-size: 0.9em; color: #fff; }
@@ -768,9 +774,14 @@ HTML_PAGE = """\
 </aside>
 <div class="content">
 <div class="input-row">
-  <input type="text" id="domain" placeholder="домен, URL или IP-адрес"
-         autofocus autocomplete="off"
-         onkeydown="if(event.key==='Enter'){event.preventDefault();checkDomain();}">
+  <div class="input-wrap">
+    <input type="text" id="domain" placeholder="домен, URL или IP-адрес"
+           autofocus autocomplete="off"
+           oninput="document.getElementById('clear-x').style.display=this.value?'block':'none'"
+           onkeydown="if(event.key==='Enter'){event.preventDefault();checkDomain();}">
+    <button type="button" class="clear-btn" id="clear-x"
+            onclick="var d=document.getElementById('domain');d.value='';d.focus();this.style.display='none';">&times;</button>
+  </div>
   <button class="btn-check" id="btn-check" onclick="checkDomain()">Проверить</button>
   <button class="btn-bypass" onclick="addEntry('bypass')">Обход (egw)</button>
   <button class="btn-direct" onclick="addEntry('direct')">Напрямую (dgw)</button>