diff --git a/backup/fileSaveLoad.js b/backup/fileSaveLoad.js
index f835bb47..faa5d204 100644
--- a/backup/fileSaveLoad.js
+++ b/backup/fileSaveLoad.js
@@ -130,13 +130,16 @@ function importFromString(jsonString) {
             </small>
           </details>`)
         .join('');
-      const box = messageBox({
+      messageBox({
         title: 'Finished importing styles',
         contents: report || 'Nothing was changed.',
         buttons: [t('confirmOK'), numChanged && t('undo')],
-        onclick: btnIndex => btnIndex == 1 && undo(),
-      });
-      bindClick(box);
+        onshow:  bindClick,
+      }).then(({button, enter, esc}) => {
+          if (button == 1) {
+            undo();
+          }
+        });
       resolve(numChanged);
     });
   }
diff --git a/manage.html b/manage.html
index 7e39d6d6..9f5fc519 100644
--- a/manage.html
+++ b/manage.html
@@ -5,7 +5,6 @@
   <title i18n-text="manageTitle"></title>
   <link rel="stylesheet" href="manage.css">
   <link rel="stylesheet" href="msgbox/msgbox.css">
-  <link rel="stylesheet" href="msgbox/confirm.css">
 
   <template data-id="style">
     <div class="entry">
@@ -117,17 +116,6 @@
 </div>
 <div id="installed"></div>
 
-<div id="confirm">
-  <div>
-    <b>Style's Name</b>
-    <span i18n-text="deleteStyleConfirm"></span>
-    <div>
-      <button i18n-text="confirmCancel" data-cmd="cancel"></button>
-      <button i18n-text="confirmDelete" data-cmd="ok"></button>
-    </div>
-  </div>
-</div>
-
 <svg xmlns="http://www.w3.org/2000/svg" style="display: none">
   <symbol id="svg-icon-external-link" height="16" width="16" viewBox="0 0 8 8">
     <path d="M0 0v8h8v-2h-1v1h-6v-6h1v-1h-2zm4 0l1.5 1.5-2.5 2.5 1 1 2.5-2.5 1.5 1.5v-4h-4z"></path>
diff --git a/manage.js b/manage.js
index 6b19ea37..5fbe0e72 100644
--- a/manage.js
+++ b/manage.js
@@ -172,7 +172,7 @@ function createStyleElement(style) {
   $('.disable', entry).onclick = EntryOnClick.toggle;
   $('.check-update', entry).onclick = EntryOnClick.check;
   $('.update', entry).onclick = EntryOnClick.update;
-  $('.delete', entry).onclick = event => confirmDelete(event, {float: true});
+  $('.delete', entry).onclick = EntryOnClick.delete;
   return entry;
 }
 
@@ -224,6 +224,23 @@ class EntryOnClick {
     }));
   }
 
+  static delete(event) {
+    const styleElement = getClickedStyleElement(event);
+    const id = styleElement.styleId;
+    const name = ((cachedStyles.byId.get(id) || {}).style || {}).name;
+    animateElement(styleElement, {className: 'highlight'});
+    messageBox({
+      title: t('deleteStyleConfirm'),
+      contents: name,
+      className: 'danger center',
+      buttons: [t('confirmDelete'), t('confirmCancel')],
+    })
+    .then(({button, enter, esc}) => {
+      if (button == 0 || enter) {
+        deleteStyle(id);
+      }
+    });
+  }
 }
 
 
diff --git a/msgbox/confirm.css b/msgbox/confirm.css
deleted file mode 100644
index 0d418fac..00000000
--- a/msgbox/confirm.css
+++ /dev/null
@@ -1,80 +0,0 @@
-#confirm,
-#confirm > div > span {
-  align-items: center;
-  justify-content: center;
-}
-
-#confirm {
-  z-index: 2147483647;
-  display: none;
-  position: fixed;
-  left: 0;
-  top: 0;
-  width: 100vw;
-  height: 100vh;
-  margin: 0 !important;
-  box-sizing: border-box;
-  animation: lights-off .5s cubic-bezier(.03, .67, .08, .94);
-  animation-fill-mode: both;
-}
-
-#confirm.lights-on {
-  animation: lights-on .25s ease-in-out;
-  animation-fill-mode: both;
-}
-
-#confirm.lights-on > div{
-  display: none;
-}
-
-#confirm[data-display=true] {
-  display: flex;
-}
-
-#confirm > div {
-  width: 80vw;
-  max-width: 16em;
-  min-height: 8em;
-  max-height: 80vh;
-  background-color: #fff;
-  display: flex;
-  flex-direction: column;
-  border: solid 2px rgba(0, 0, 0, 0.5);
-}
-
-#confirm > div > span {
-  display: flex;
-  flex: 1;
-  padding: 0 10px;
-}
-
-#confirm > div > b {
-  padding: 10px;
-  white-space: nowrap;
-  overflow: hidden;
-  text-overflow: ellipsis;
-}
-
-#confirm > div > div {
-  padding: 10px;
-  direction: rtl;
-}
-
-@keyframes lights-off {
-  from {
-    background-color: transparent;
-  }
-  to {
-    background-color: rgba(0, 0, 0, 0.4);
-  }
-}
-
-@keyframes lights-on {
-  from {
-    background-color: rgba(0, 0, 0, 0.4);
-  }
-  to {
-    background-color: transparent;
-  }
-}
-
diff --git a/msgbox/confirm.js b/msgbox/confirm.js
deleted file mode 100644
index f77cc489..00000000
--- a/msgbox/confirm.js
+++ /dev/null
@@ -1,50 +0,0 @@
-function confirmDelete(event, {float = false} = {}) {
-  const id = getClickedStyleId(event);
-  const box = $('#confirm');
-  box.dataset.id = id;
-  box.dataset.display = true;
-  box.style.cssText = '';
-  $('b', box).textContent = ((cachedStyles.byId.get(id) || {}).style || {}).name;
-  if (float) {
-    const GAP = 50;
-    const {width:W, height:H} = box.firstElementChild.getBoundingClientRect();
-    const {left:L, top:T, right:R, bottom:B} = event.target.getBoundingClientRect();
-    Object.assign(box.style, {
-      paddingTop: (Math.min(T - H/2, innerHeight - H) - GAP) + 'px',
-      paddingLeft: (Math.min(L - W/2, innerWidth - W) - GAP) + 'px',
-      paddingRight: (innerWidth - Math.max(R + W/2, W) - GAP) + 'px',
-      paddingBottom: (innerHeight - Math.max(B + H/2, H) - GAP) + 'px',
-    });
-  }
-  let resolveMe;
-  $('[data-cmd="ok"]', box).onclick = event => doDelete(true);
-  $('[data-cmd="cancel"]', box).onclick = event => doDelete(false);
-  window.addEventListener('keydown', onKey);
-
-  const stopScroll = {x: scrollX, y: scrollY};
-  window.addEventListener('scroll', preventScroll);
-
-  return new Promise(resolve => resolveMe = resolve);
-
-  function doDelete(confirmed) {
-    window.removeEventListener('keydown', onKey);
-    window.removeEventListener('scroll', preventScroll);
-    animateElement(box, {className: 'lights-on'}).then(() => {
-      box.dataset.display = false;
-    });
-    Promise.resolve(confirmed && deleteStyle(id))
-      .then(resolveMe);
-  }
-
-  function onKey(event) {
-    if (!event.shiftKey && !event.ctrlKey && !event.altKey && !event.metaKey
-    && (event.keyCode == 13 || event.keyCode == 27)) {
-      event.preventDefault();
-      doDelete(event.keyCode == 13);
-    }
-  }
-
-  function preventScroll() {
-    window.scrollTo(stopScroll.x, stopScroll.y);
-  }
-}
diff --git a/msgbox/msgbox.css b/msgbox/msgbox.css
index eeebb4eb..79357fab 100644
--- a/msgbox/msgbox.css
+++ b/msgbox/msgbox.css
@@ -1,4 +1,17 @@
 #message-box {
+  top: 0;
+  left: 0;
+  right: 0;
+  bottom: 0;
+  display: flex;
+  position: fixed;
+  box-shadow: 5px 5px 50px rgba(0, 0, 0, 0.35);
+  background-color: rgba(0, 0, 0, .25);
+  animation: fadein .25s ease-in-out;
+  z-index: 9999990;
+}
+
+#message-box > div {
   top: 3rem;
   right: 3rem;
   min-width: 10rem;
@@ -7,41 +20,36 @@
   max-height: 90vh;
   position: fixed;
   display: flex;
-  box-shadow: 5px 5px 50px rgba(0, 0, 0, 0.35);
-  animation: fadein .25s ease-in-out;
   flex-direction: column;
-  z-index: 9999990;
-}
-
-#message-box > * {
-  z-index: 9999991;
   background-color: white;
+  box-shadow: 5px 5px 50px rgba(0, 0, 0, 0.35);
+  z-index: 9999991;
 }
 
 #message-box.fadeout {
   animation: fadeout .5s ease-in-out;
 }
 
-#message-box::before {
-  position: fixed;
-  content: "";
-  top: 0;
-  left: 0;
-  right: 0;
-  bottom: 0;
-  background-color: rgba(0, 0, 0, .25);
+#message-box.center {
+  align-items: center;
+  justify-content: center;
 }
 
-#message-box.big {
-  max-width: none;
-  left: 3rem;
+#message-box.center #message-box-contents {
+  text-align: center;
+}
+
+#message-box.center > div {
+  top: unset;
+  right: unset;
 }
 
 #message-box-title {
   font-weight: bold;
   background-color: rgb(145, 208, 198);
-  padding: .75rem 50px .75rem .75rem;
+  padding: .75rem 50px .75rem 52px;
   font-size: 1rem;
+  position: relative;
 }
 
 #message-box-title::before {
@@ -49,10 +57,23 @@
   width: 0;
   height: 0;
   padding: 0 32px 32px 0;
-  background: url('/images/icon/32.png');
-  display: inline-block;
-  vertical-align: middle;
-  margin-right: .5rem;
+  background: url(/images/icon/32.png);
+  position: absolute;
+  left: 11px;
+  top: 8px;
+}
+
+#message-box.danger #message-box-title {
+  background-color: firebrick;
+  color: white;
+}
+
+#message-box.danger #message-box-title::before {
+  background: url('/images/icon/32x.png');
+}
+
+#message-box.danger #message-box-contents {
+  font-weight: bold;
 }
 
 #message-box-close-icon {
@@ -68,7 +89,7 @@
 
 #message-box-contents {
   overflow: auto;
-  padding: .75rem;
+  padding: 1.5rem .75rem;
   position: relative;
   flex-grow: 9;
 }
@@ -76,6 +97,7 @@
 #message-box-buttons {
   padding: .75rem;
   background-color: #f0f0f0;
+  text-align: center;
 }
 
 #message-box-buttons button:not(:last-child) {
diff --git a/msgbox/msgbox.js b/msgbox/msgbox.js
index af5f3617..310a998f 100644
--- a/msgbox/msgbox.js
+++ b/msgbox/msgbox.js
@@ -1,51 +1,90 @@
 'use strict';
 
-function messageBox({title, contents, buttons, onclick}) {
-  // keep the same reference to be able to remove the listener later
-  messageBox.close = messageBox.close || close;
-  if (messageBox.element) {
-    messageBox.element.remove();
+function messageBox({
+  title,          // [mandatory] the title string for innerHTML
+  contents,       // [mandatory] 1) DOM element 2) string for innerHTML
+  className = '', // string, CSS class name of the message box element
+  buttons = [],   // array of strings used as labels
+  onshow,         // function(messageboxElement) invoked after the messagebox is shown
+  blockScroll,    // boolean, blocks the page scroll
+}) {              // RETURNS: Promise resolved to {button[number], enter[boolean], esc[boolean]}
+  initOwnListeners();
+  bindGlobalListeners();
+  createElement();
+  document.body.appendChild(messageBox.element);
+  if (onshow) {
+    onshow(messageBox.element);
   }
-  const id = 'message-box';
-  const putAs = typeof contents == 'string' ? 'innerHTML' : 'appendChild';
-  messageBox.element = $element({id, appendChild: [
-    $element({id: `${id}-title`, innerHTML: title}),
-    $element({id: `${id}-close-icon`, onclick: messageBox.close}),
-    $element({id: `${id}-contents`, [putAs]: contents}),
-    $element({id: `${id}-buttons`,
-      onclick: relayButtonClick,
-      appendChild: (buttons || []).map(textContent =>
-        textContent && $element({tag: 'button', textContent}))
-    }),
-  ]});
-  show();
-  return messageBox.element;
+  return new Promise(_resolve => {
+    messageBox.resolve = _resolve;
+  });
 
-  function show() {
-    document.body.appendChild(messageBox.element);
-    document.addEventListener('keydown', messageBox.close);
-  }
-
-  function close(event) {
-    if ((!event
-    || event.type == 'click'
-    || event.keyCode == 27 && !event.altKey && !event.ctrlKey && !event.shiftKey && !event.metaKey)
-    && messageBox.element) {
-      animateElement(messageBox.element, {className: 'fadeout', remove: true});
-      document.removeEventListener('keydown', messageBox.close);
-      $(`#${id}-buttons`).onclick = null;
-      messageBox.element = null;
-    }
-  }
-
-  function relayButtonClick(event) {
-    const button = event.target.closest('button');
-    if (button) {
-      close();
-      if (onclick) {
-        onclick([...this.children].indexOf(button));
+  function initOwnListeners() {
+    messageBox.listeners = messageBox.listeners || {
+      closeIcon() {
+        resolveWith({button: -1});
+      },
+      button() {
+        resolveWith({button: this.buttonIndex});
+      },
+      key(event) {
+        if (!event.shiftKey && !event.ctrlKey && !event.altKey && !event.metaKey
+        && (event.keyCode == 13 || event.keyCode == 27)) {
+          event.preventDefault();
+          resolveWith(event.keyCode == 13 ? {enter: true} : {esc: true});
+        }
+      },
+      scroll() {
+        scrollTo(blockScroll.x, blockScroll.y);
       }
+    };
+  }
+
+  function resolveWith(value) {
+    setTimeout(messageBox.resolve, 0, value);
+    animateElement(messageBox.element, {className: 'fadeout', remove: true})
+      .then(unbindAndRemoveSelf);
+  }
+
+  function createElement() {
+    if (messageBox.element) {
+      unbindAndRemoveSelf();
     }
+    const id = 'message-box';
+    const putAs = typeof contents == 'string' ? 'innerHTML' : 'appendChild';
+    messageBox.element = $element({id, className, appendChild: [
+      $element({appendChild: [
+        $element({id: `${id}-title`, innerHTML: title}),
+        $element({id: `${id}-close-icon`, onclick: messageBox.listeners.closeIcon}),
+        $element({id: `${id}-contents`, [putAs]: contents}),
+        $element({id: `${id}-buttons`, appendChild:
+          buttons.map((textContent, buttonIndex) => textContent &&
+            $element({
+              tag: 'button',
+              buttonIndex,
+              textContent,
+              onclick: messageBox.listeners.button,
+            })
+          )
+        }),
+      ]}),
+    ]});
+  }
+
+  function bindGlobalListeners() {
+    blockScroll = blockScroll && {x: scrollX, y: scrollY};
+    if (blockScroll) {
+      window.addEventListener('scroll', messageBox.listeners.scroll);
+    }
+    window.addEventListener('keydown', messageBox.listeners.key);
+  }
+
+  function unbindAndRemoveSelf() {
+    document.removeEventListener('keydown', messageBox.listeners.key);
+    window.removeEventListener('scroll', messageBox.listeners.scroll);
+    messageBox.element.remove();
+    messageBox.element = null;
+    messageBox.resolve = null;
   }
 
   function $element(opt) {
diff --git a/popup.css b/popup.css
index d1e0f2a5..b667f95c 100644
--- a/popup.css
+++ b/popup.css
@@ -212,3 +212,75 @@ body>div:not(#installed) {
   white-space: nowrap;
   padding-right: 5px;
 }
+  /* confirm */
+#confirm,
+#confirm>div>span {
+  align-items: center;
+  justify-content: center;
+}
+#confirm {
+  z-index: 2147483647;
+  display: none; /* flex */
+  position: absolute;
+  left: 0;
+  top: 0;
+  width: 100%;
+  height: 100%;
+  margin:  0!important;
+  box-sizing: border-box;
+  background-color: rgba(0, 0, 0, 0.4);
+  animation: lights-off .5s cubic-bezier(.03, .67, .08, .94);
+  animation-fill-mode: both;
+}
+#confirm.lights-on {
+  animation: lights-on .25s ease-in-out;
+  animation-fill-mode: both;
+}
+#confirm.lights-on > div{
+  display: none;
+}
+#confirm[data-display=true] {
+  display: flex;
+}
+#confirm>div {
+  width: 80%;
+  height: 100px;
+  max-height: 80%;
+  min-height: 8em;
+  background-color: #fff;
+  display: flex;
+  flex-direction: column;
+  border: solid 2px rgba(0, 0, 0, 0.5);
+}
+#confirm>div>span {
+  display: flex;
+  flex: 1;
+  padding: 0 10px;
+}
+#confirm>div>b {
+  padding: 10px;
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
+}
+#confirm>div>div {
+  padding: 10px;
+  direction: rtl;
+}
+@keyframes lights-off {
+  from {
+    background-color: transparent;
+  }
+  to {
+    background-color: rgba(0, 0, 0, 0.4);
+  }
+}
+@keyframes lights-on {
+  from {
+    background-color: rgba(0, 0, 0, 0.4);
+  }
+  to {
+    background-color: transparent;
+  }
+}
+
diff --git a/popup.html b/popup.html
index 9ef10321..5ced4326 100644
--- a/popup.html
+++ b/popup.html
@@ -3,7 +3,6 @@
 <head>
     <meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
     <link rel="stylesheet" href="popup.css">
-    <link rel="stylesheet" href="msgbox/confirm.css">
 
     <template data-id="style">
         <div class="entry">
@@ -44,7 +43,6 @@
     <script src="messaging.js"></script>
     <script src="apply.js"></script>
     <script src="dom.js"></script>
-    <script src="msgbox/confirm.js"></script>
 
     <script src="popup.js"></script>
 </head>
diff --git a/popup.js b/popup.js
index 079737b1..20d6098f 100644
--- a/popup.js
+++ b/popup.js
@@ -188,12 +188,33 @@ class EntryOnClick {
   }
 
   static delete(event) {
-    confirmDelete(event).then(() => {
-      // update view with 'No styles installed for this site' message
-      if (!installed.children.length) {
-        showStyles([]);
+    const id = getClickedStyleId(event);
+    const box = $('#confirm');
+    box.dataset.display = true;
+    box.style.cssText = '';
+    $('b', box).textContent = ((cachedStyles.byId.get(id) || {}).style || {}).name;
+    $('[data-cmd="ok"]', box).onclick = () => confirm(true);
+    $('[data-cmd="cancel"]', box).onclick = () => confirm(false);
+    window.onkeydown = event => {
+      if (!event.shiftKey && !event.ctrlKey && !event.altKey && !event.metaKey
+      && (event.keyCode == 13 || event.keyCode == 27)) {
+        event.preventDefault();
+        confirm(event.keyCode == 13);
       }
-    });
+    };
+    function confirm(ok) {
+      window.onkeydown = null;
+      animateElement(box, {className: 'lights-on'})
+        .then(() => box.dataset.display = false);
+      if (ok) {
+        deleteStyle(id).then(() => {
+          // update view with 'No styles installed for this site' message
+          if (!installed.children.length) {
+            showStyles([]);
+          }
+        });
+      }
+    }
   }
 
 }