[bug fixes] fixed typos in the new tmpls

src-tauri/templates/overlay/countdown/countdown.css.j2

@@ -13,8 +13,8 @@
   justify-content: center;
   height: 100vh;
 }
-.countdown-item.hidden {
-  display: none;
+.countdown-item[data-hidden="true"] {
+    display: none;
 }
 {% for c in countdowns %}
 #timer-{{ c.id }} {

src-tauri/templates/overlay/countdown/countdown.html.j2

@@ -2,10 +2,15 @@
   {% for c in countdowns %}
     <div
       id="countdown-{{ c.id }}"
-      class="countdown-item{% if hide_idle and c.state == 'Idle' %}hidden{% endif %}"
+      class="countdown-item"
+      data-hidden="{{ hide_idle and c.state == 'Idle' }}"
     >
       {% if c.icon %}
-        <img id="icon-{{ c.id }}" src="{{ c.icon }}" alt="{{ c.name }}" />
+        <img
+          id="icon-{{ c.id }}"
+          src="/static/icons/{{ c.icon }}"
+          alt="{{ c.name }}"
+        />
       {% endif %}
       <span
         id="timer-{{ c.id }}"