diff --git a/app/assets/javascripts/admin/components/themes-list-item.js.es6 b/app/assets/javascripts/admin/components/themes-list-item.js.es6
index fe5243585b..44f337dd76 100644
--- a/app/assets/javascripts/admin/components/themes-list-item.js.es6
+++ b/app/assets/javascripts/admin/components/themes-list-item.js.es6
@@ -1,32 +1,136 @@
-import { default as computed } from "ember-addons/ember-computed-decorators";
+import {
+  default as computed,
+  observes
+} from "ember-addons/ember-computed-decorators";
 
 const MAX_COMPONENTS = 4;
 
 export default Ember.Component.extend({
+  childrenExpanded: false,
   classNames: ["themes-list-item"],
-  classNameBindings: ["theme.active:active"],
+  classNameBindings: ["theme.selected:selected"],
   hasComponents: Em.computed.gt("children.length", 0),
-  hasMore: Em.computed.gt("moreCount", 0),
+  displayComponents: Em.computed.and("hasComponents", "theme.isActive"),
+  displayHasMore: Em.computed.gt("theme.childThemes.length", MAX_COMPONENTS),
+
+  click(e) {
+    if (!$(e.target).hasClass("others-count")) {
+      this.navigateToTheme();
+    }
+  },
+
+  init() {
+    this._super(...arguments);
+    this.scheduleAnimation();
+  },
+
+  @observes("theme.selected")
+  triggerAnimation() {
+    this.animate();
+  },
+
+  scheduleAnimation() {
+    Ember.run.schedule("afterRender", () => {
+      this.animate(true);
+    });
+  },
+
+  animate(isInitial) {
+    const $container = this.$();
+    const $list = this.$(".components-list");
+    if ($list.length === 0 || Ember.testing) {
+      return;
+    }
+    const duration = 300;
+    if (this.get("theme.selected")) {
+      this.collapseComponentsList($container, $list, duration);
+    } else if (!isInitial) {
+      this.expandComponentsList($container, $list, duration);
+    }
+  },
 
   @computed(
     "theme.component",
     "theme.childThemes.@each.name",
-    "theme.childThemes.length"
+    "theme.childThemes.length",
+    "childrenExpanded"
   )
   children() {
     const theme = this.get("theme");
-    const children = theme.get("childThemes");
+    let children = theme.get("childThemes");
     if (theme.get("component") || !children) {
       return [];
     }
-    return children.slice(0, MAX_COMPONENTS).map(t => t.get("name"));
+    children = this.get("childrenExpanded")
+      ? children
+      : children.slice(0, MAX_COMPONENTS);
+    return children.map(t => t.get("name"));
   },
 
-  @computed("theme.childThemes.length", "theme.component", "children.length")
-  moreCount(childrenCount, component) {
-    if (component || !childrenCount) {
+  @computed(
+    "theme.childThemes.length",
+    "theme.component",
+    "childrenExpanded",
+    "children.length"
+  )
+  moreCount(childrenCount, component, expanded) {
+    if (component || !childrenCount || expanded) {
       return 0;
     }
     return childrenCount - MAX_COMPONENTS;
+  },
+
+  expandComponentsList($container, $list, duration) {
+    $container.css("height", `${$container.height()}px`);
+    $list.css("display", "");
+    $container.animate(
+      {
+        height: `${$container.height() + $list.outerHeight(true)}px`
+      },
+      {
+        duration,
+        done: () => {
+          $list.css("display", "");
+          $container.css("height", "");
+        }
+      }
+    );
+    $list.animate(
+      {
+        opacity: 1
+      },
+      {
+        duration
+      }
+    );
+  },
+
+  collapseComponentsList($container, $list, duration) {
+    $container.animate(
+      {
+        height: `${$container.height() - $list.outerHeight(true)}px`
+      },
+      {
+        duration,
+        done: () => {
+          $list.css("display", "none");
+          $container.css("height", "");
+        }
+      }
+    );
+    $list.animate(
+      {
+        opacity: 0
+      },
+      {
+        duration
+      }
+    );
+  },
+
+  actions: {
+    toggleChildrenExpanded() {
+      this.toggleProperty("childrenExpanded");
+    }
   }
 });
diff --git a/app/assets/javascripts/admin/components/themes-list.js.es6 b/app/assets/javascripts/admin/components/themes-list.js.es6
index cf41e4dd33..c9498566c3 100644
--- a/app/assets/javascripts/admin/components/themes-list.js.es6
+++ b/app/assets/javascripts/admin/components/themes-list.js.es6
@@ -1,7 +1,7 @@
 import { THEMES, COMPONENTS } from "admin/models/theme";
 import { default as computed } from "ember-addons/ember-computed-decorators";
 
-const NUM_ENTRIES = 8;
+const MAX_LIST_HEIGHT = 700;
 
 export default Ember.Component.extend({
   THEMES: THEMES,
@@ -63,15 +63,24 @@ export default Ember.Component.extend({
   },
 
   didRender() {
-    let height = -1;
-    this.$(".themes-list-item")
-      .slice(0, NUM_ENTRIES)
-      .each(function() {
-        height += $(this).outerHeight();
-      });
-    if (height >= 485 && height <= 800) {
-      this.$(".themes-list-container").css("max-height", `${height}px`);
+    this._super(...arguments);
+
+    // hide scrollbar
+    const $container = this.$(".themes-list-container");
+    const containerNode = $container[0];
+    if (containerNode) {
+      const width = containerNode.offsetWidth - containerNode.clientWidth;
+      $container.css("width", `calc(100% + ${width}px)`);
     }
+
+    let height = -1;
+    Array.from(this.$(".themes-list-item")).forEach(node => {
+      const nodeHeight = $(node).outerHeight();
+      if (height + nodeHeight <= MAX_LIST_HEIGHT) {
+        height += nodeHeight;
+      }
+    });
+    $container.css("max-height", `${height}px`);
   },
 
   actions: {
@@ -79,6 +88,11 @@ export default Ember.Component.extend({
       if (newTab !== this.get("currentTab")) {
         this.set("currentTab", newTab);
       }
+    },
+    navigateToTheme(theme) {
+      Em.getOwner(this)
+        .lookup("router:main")
+        .transitionTo("adminCustomizeThemes.show", theme);
     }
   }
 });
diff --git a/app/assets/javascripts/admin/controllers/admin-customize-themes-edit.js.es6 b/app/assets/javascripts/admin/controllers/admin-customize-themes-edit.js.es6
index 7cbe893fe5..c8082cc84d 100644
--- a/app/assets/javascripts/admin/controllers/admin-customize-themes-edit.js.es6
+++ b/app/assets/javascripts/admin/controllers/admin-customize-themes-edit.js.es6
@@ -5,8 +5,10 @@ import {
 } from "ember-addons/ember-computed-decorators";
 
 export default Ember.Controller.extend({
-  maximized: false,
   section: null,
+  currentTarget: 0,
+  maximized: false,
+  previewUrl: url("model.id", "/admin/themes/%@/preview"),
 
   editRouteName: "adminCustomizeThemes.edit",
 
@@ -86,8 +88,6 @@ export default Ember.Controller.extend({
     return this.get("model").hasEdited(target);
   },
 
-  currentTarget: 0,
-
   setTargetName: function(name) {
     const target = this.get("targets").find(t => t.name === name);
     this.set("currentTarget", target && target.id);
@@ -152,21 +152,20 @@ export default Ember.Controller.extend({
     });
   },
 
-  previewUrl: url("model.id", "/admin/themes/%@/preview"),
+  @computed("maximized")
+  maximizeIcon(maximized) {
+    return maximized ? "compress" : "expand";
+  },
 
-  maximizeIcon: function() {
-    return this.get("maximized") ? "compress" : "expand";
-  }.property("maximized"),
+  @computed("model.isSaving")
+  saveButtonText(isSaving) {
+    return isSaving ? I18n.t("saving") : I18n.t("admin.customize.save");
+  },
 
-  saveButtonText: function() {
-    return this.get("model.isSaving")
-      ? I18n.t("saving")
-      : I18n.t("admin.customize.save");
-  }.property("model.isSaving"),
-
-  saveDisabled: function() {
-    return !this.get("model.changed") || this.get("model.isSaving");
-  }.property("model.changed", "model.isSaving"),
+  @computed("model.changed", "model.isSaving")
+  saveDisabled(changed, isSaving) {
+    return !changed || isSaving;
+  },
 
   actions: {
     save() {
diff --git a/app/assets/javascripts/admin/controllers/admin-customize-themes-show.js.es6 b/app/assets/javascripts/admin/controllers/admin-customize-themes-show.js.es6
index c73d4467fd..47b59317f1 100644
--- a/app/assets/javascripts/admin/controllers/admin-customize-themes-show.js.es6
+++ b/app/assets/javascripts/admin/controllers/admin-customize-themes-show.js.es6
@@ -9,106 +9,65 @@ import ThemeSettings from "admin/models/theme-settings";
 import { THEMES, COMPONENTS } from "admin/models/theme";
 
 const THEME_UPLOAD_VAR = 2;
-const SETTINGS_TYPE_ID = 5;
 
 export default Ember.Controller.extend({
-  editRouteName: "adminCustomizeThemes.edit",
-
-  @observes("allowChildThemes")
-  setSelectedThemeId() {
-    const available = this.get("selectableChildThemes");
-    if (
-      !this.get("selectedChildThemeId") &&
-      available &&
-      available.length > 0
-    ) {
-      this.set("selectedChildThemeId", available[0].get("id"));
-    }
-  },
+  downloadUrl: url("model.id", "/admin/themes/%@"),
+  previewUrl: url("model.id", "/admin/themes/%@/preview"),
+  addButtonDisabled: Em.computed.empty("selectedChildThemeId"),
 
   @computed("model", "allThemes", "model.component")
   parentThemes(model, allThemes) {
     if (!model.get("component")) {
       return null;
     }
-    let parents = allThemes.filter(theme =>
+    const parents = allThemes.filter(theme =>
       _.contains(theme.get("childThemes"), model)
     );
     return parents.length === 0 ? null : parents;
   },
 
-  @computed("model.theme_fields.@each")
-  hasEditedFields(fields) {
-    return fields.any(
-      f => !Em.isBlank(f.value) && f.type_id !== SETTINGS_TYPE_ID
-    );
-  },
-
-  @computed("model.theme_fields.@each")
-  editedDescriptions(fields) {
-    let descriptions = [];
-    let description = target => {
-      let current = fields.filter(
-        field => field.target === target && !Em.isBlank(field.value)
-      );
-      if (current.length > 0) {
-        let text = I18n.t("admin.customize.theme." + target);
-        let localized = current.map(f =>
-          I18n.t("admin.customize.theme." + f.name + ".text")
-        );
-        return text + ": " + localized.join(" , ");
-      }
-    };
+  @computed("model.editedFields")
+  editedFieldsFormatted(fields) {
+    const descriptions = [];
     ["common", "desktop", "mobile"].forEach(target => {
-      descriptions.push(description(target));
+      const fields = this.editedFieldsForTarget(target);
+      if (fields.length < 1) {
+        return;
+      }
+      let resultString = I18n.t("admin.customize.theme." + target);
+      const formattedFields = fields
+        .map(f => I18n.t("admin.customize.theme." + f.name + ".text"))
+        .join(" , ");
+      resultString += `: ${formattedFields}`;
+      descriptions.push(resultString);
     });
-    return descriptions.reject(d => Em.isBlank(d));
+    return descriptions;
   },
 
-  previewUrl: url("model.id", "/admin/themes/%@/preview"),
-
   @computed("colorSchemeId", "model.color_scheme_id")
   colorSchemeChanged(colorSchemeId, existingId) {
     colorSchemeId = colorSchemeId === null ? null : parseInt(colorSchemeId);
     return colorSchemeId !== existingId;
   },
 
-  @computed(
-    "availableChildThemes",
-    "model.childThemes.@each",
-    "model",
-    "allowChildThemes"
-  )
-  selectableChildThemes(available, childThemes, allowChildThemes) {
-    if (!allowChildThemes && (!childThemes || childThemes.length === 0)) {
-      return null;
+  @computed("availableChildThemes", "model.childThemes.@each", "model")
+  selectableChildThemes(available, childThemes) {
+    if (available) {
+      const themes = !childThemes
+        ? available
+        : available.filter(theme => childThemes.indexOf(theme) === -1);
+      return themes.length === 0 ? null : themes;
     }
-
-    let themes = [];
-    available.forEach(t => {
-      if (!childThemes || childThemes.indexOf(t) === -1) {
-        themes.push(t);
-      }
-    });
-    return themes.length === 0 ? null : themes;
   },
 
-  @computed("allThemes", "allThemes.length", "model.component", "model")
-  availableChildThemes(allThemes, count, component) {
-    if (count === 1 || component) {
-      return null;
+  @computed("allThemes", "model.component", "model")
+  availableChildThemes(allThemes) {
+    if (!this.get("model.component")) {
+      const themeId = this.get("model.id");
+      return allThemes.filter(
+        theme => theme.get("id") !== themeId && theme.get("component")
+      );
     }
-
-    const themeId = this.get("model.id");
-
-    let themes = [];
-    allThemes.forEach(theme => {
-      if (themeId !== theme.get("id") && theme.get("component")) {
-        themes.push(theme);
-      }
-    });
-
-    return themes;
   },
 
   @computed("model.component")
@@ -137,8 +96,11 @@ export default Ember.Controller.extend({
   hasSettings(settings) {
     return settings.length > 0;
   },
-
-  downloadUrl: url("model.id", "/admin/themes/%@"),
+  editedFieldsForTarget(target) {
+    return this.get("model.editedFields").filter(
+      field => field.target === target
+    );
+  },
 
   commitSwitchType() {
     const model = this.get("model");
@@ -146,7 +108,6 @@ export default Ember.Controller.extend({
     model.set("component", newValue);
 
     if (newValue) {
-      // component
       this.set("parentController.currentTab", COMPONENTS);
     } else {
       this.set("parentController.currentTab", THEMES);
@@ -166,8 +127,8 @@ export default Ember.Controller.extend({
         });
 
         this.get("parentController.model.content").forEach(theme => {
-          const children = Array.from(theme.get("childThemes"));
-          const rawChildren = Array.from(theme.get("child_themes") || []);
+          const children = _.toArray(theme.get("childThemes"));
+          const rawChildren = _.toArray(theme.get("child_themes") || []);
           const index = children ? children.indexOf(model) : -1;
           if (index > -1) {
             children.splice(index, 1);
@@ -181,7 +142,14 @@ export default Ember.Controller.extend({
       })
       .catch(popupAjaxError);
   },
-
+  transitionToEditRoute() {
+    this.transitionToRoute(
+      "adminCustomizeThemes.edit",
+      this.get("model.id"),
+      "common",
+      "scss"
+    );
+  },
   actions: {
     updateToLatest() {
       this.set("updatingRemote", true);
@@ -238,25 +206,17 @@ export default Ember.Controller.extend({
     },
 
     editTheme() {
-      let edit = () =>
-        this.transitionToRoute(
-          this.get("editRouteName"),
-          this.get("model.id"),
-          "common",
-          "scss"
-        );
-
       if (this.get("model.remote_theme")) {
         bootbox.confirm(
           I18n.t("admin.customize.theme.edit_confirm"),
           result => {
             if (result) {
-              edit();
+              this.transitionToEditRoute();
             }
           }
         );
       } else {
-        edit();
+        this.transitionToEditRoute();
       }
     },
 
diff --git a/app/assets/javascripts/admin/models/theme.js.es6 b/app/assets/javascripts/admin/models/theme.js.es6
index fa37798fc0..413d9a93c6 100644
--- a/app/assets/javascripts/admin/models/theme.js.es6
+++ b/app/assets/javascripts/admin/models/theme.js.es6
@@ -6,9 +6,13 @@ const THEME_UPLOAD_VAR = 2;
 
 export const THEMES = "themes";
 export const COMPONENTS = "components";
+const SETTINGS_TYPE_ID = 5;
 
 const Theme = RestModel.extend({
   FIELDS_IDS: [0, 1],
+  isActive: Em.computed.or("default", "user_selectable"),
+  isPendingUpdates: Em.computed.gt("remote_theme.commits_behind", 0),
+  hasEditedFields: Em.computed.gt("editedFields.length", 0),
 
   @computed("theme_fields")
   themeFields(fields) {
@@ -43,9 +47,11 @@ const Theme = RestModel.extend({
     );
   },
 
-  @computed("remote_theme", "remote_theme.commits_behind")
-  isPendingUpdates(remote, commitsBehind) {
-    return remote && commitsBehind && commitsBehind > 0;
+  @computed("theme_fields.@each")
+  editedFields(fields) {
+    return fields.filter(
+      field => !Em.isBlank(field.value) && field.type_id !== SETTINGS_TYPE_ID
+    );
   },
 
   getKey(field) {
diff --git a/app/assets/javascripts/admin/routes/admin-customize-themes-edit.js.es6 b/app/assets/javascripts/admin/routes/admin-customize-themes-edit.js.es6
index 7b63658ac0..5bab290091 100644
--- a/app/assets/javascripts/admin/routes/admin-customize-themes-edit.js.es6
+++ b/app/assets/javascripts/admin/routes/admin-customize-themes-edit.js.es6
@@ -35,5 +35,29 @@ export default Ember.Route.extend({
     controller.setTargetName(wrapper.target || "common");
     controller.set("fieldName", wrapper.field_name || "scss");
     this.controllerFor("adminCustomizeThemes").set("editingTheme", true);
+    this.set("shouldAlertUnsavedChanges", true);
+  },
+
+  actions: {
+    willTransition(transition) {
+      if (
+        this.get("controller.model.changed") &&
+        this.get("shouldAlertUnsavedChanges") &&
+        transition.intent.name !== this.routeName
+      ) {
+        transition.abort();
+        bootbox.confirm(
+          I18n.t("admin.customize.theme.unsaved_changes_alert"),
+          I18n.t("admin.customize.theme.discard"),
+          I18n.t("admin.customize.theme.stay"),
+          result => {
+            if (!result) {
+              this.set("shouldAlertUnsavedChanges", false);
+              transition.retry();
+            }
+          }
+        );
+      }
+    }
   }
 });
diff --git a/app/assets/javascripts/admin/routes/admin-customize-themes-index.js.es6 b/app/assets/javascripts/admin/routes/admin-customize-themes-index.js.es6
index e1a5bf51db..e29ef8659e 100644
--- a/app/assets/javascripts/admin/routes/admin-customize-themes-index.js.es6
+++ b/app/assets/javascripts/admin/routes/admin-customize-themes-index.js.es6
@@ -1,5 +1,25 @@
+const externalResources = [
+  {
+    key: "admin.customize.theme.beginners_guide_title",
+    link: "https://meta.discourse.org/t/91966",
+    icon: "book"
+  },
+  {
+    key: "admin.customize.theme.developers_guide_title",
+    link: "https://meta.discourse.org/t/93648",
+    icon: "book"
+  },
+  {
+    key: "admin.customize.theme.browse_themes",
+    link: "https://meta.discourse.org/c/theme",
+    icon: "paint-brush"
+  }
+];
+
 export default Ember.Route.extend({
-  setupController() {
+  setupController(controller, model) {
+    this._super(...arguments);
     this.controllerFor("adminCustomizeThemes").set("editingTheme", false);
+    controller.set("externalResources", externalResources);
   }
 });
diff --git a/app/assets/javascripts/admin/routes/admin-customize-themes-show.js.es6 b/app/assets/javascripts/admin/routes/admin-customize-themes-show.js.es6
index f3736ffa74..f39b747ef7 100644
--- a/app/assets/javascripts/admin/routes/admin-customize-themes-show.js.es6
+++ b/app/assets/javascripts/admin/routes/admin-customize-themes-show.js.es6
@@ -37,9 +37,11 @@ export default Ember.Route.extend({
   },
 
   handleHighlight(theme) {
-    this.get("controller.allThemes").forEach(t => t.set("active", false));
+    this.get("controller.allThemes")
+      .filter(t => t.get("selected"))
+      .forEach(t => t.set("selected", false));
     if (theme) {
-      theme.set("active", true);
+      theme.set("selected", true);
     }
   },
 
diff --git a/app/assets/javascripts/admin/templates/components/themes-list-item.hbs b/app/assets/javascripts/admin/templates/components/themes-list-item.hbs
index 3cde5084b0..a12ddb4123 100644
--- a/app/assets/javascripts/admin/templates/components/themes-list-item.hbs
+++ b/app/assets/javascripts/admin/templates/components/themes-list-item.hbs
@@ -1,4 +1,4 @@
-{{#link-to 'adminCustomizeThemes.show' theme replace=true}}
+<div class="inner-wrapper">
   {{plugin-outlet name="admin-customize-themes-list-item" connectorTagName='span' args=(hash theme=theme)}}
 
   <div class="info">
@@ -7,28 +7,38 @@
     </span>
 
     <span class="icons">
-      {{#if theme.default}}
-        {{d-icon "check" class="default-indicator" title="admin.customize.theme.default_theme_tooltip"}}
-      {{/if}}
-      {{#if theme.isPendingUpdates}}
-        {{d-icon "refresh" title="admin.customize.theme.updates_available_tooltip" class="light-grey-icon"}}
-      {{/if}}
-      {{#if theme.isBroken}}
-        {{d-icon "exclamation-circle" class="broken-indicator" title="admin.customize.theme.broken_theme_tooltip"}}
-      {{/if}}
+      {{#unless theme.selected}}
+        {{#if theme.default}}
+          {{d-icon "check" class="default-indicator" title="admin.customize.theme.default_theme_tooltip"}}
+        {{/if}}
+        {{#if theme.isPendingUpdates}}
+          {{d-icon "refresh" title="admin.customize.theme.updates_available_tooltip" class="light-grey-icon"}}
+        {{/if}}
+        {{#if theme.isBroken}}
+          {{d-icon "exclamation-circle" class="broken-indicator" title="admin.customize.theme.broken_theme_tooltip"}}
+        {{/if}}
+      {{else}}
+        {{d-icon "caret-right"}}
+      {{/unless}}
     </span>
   </div>
 
-  {{#if hasComponents}}
+  {{#if displayComponents}}
     <div class="components-list">
       {{#each children as |child|}}
         <span class="component">
           {{child}}
         </span>
       {{/each}}
-      {{#if hasMore}}
-        <span class="others-count">{{I18n "admin.customize.theme.and_x_more" count=moreCount}}</span>
+      {{#if displayHasMore}}
+        <span {{action "toggleChildrenExpanded"}} class="others-count">
+          {{#if childrenExpanded}}
+            {{I18n "admin.customize.theme.collapse"}}
+          {{else}}
+            {{I18n "admin.customize.theme.and_x_more" count=moreCount}}
+          {{/if}}
+        </span>
       {{/if}}
     </div>
   {{/if}}
-{{/link-to}}
+</div>
diff --git a/app/assets/javascripts/admin/templates/components/themes-list.hbs b/app/assets/javascripts/admin/templates/components/themes-list.hbs
index 53a404b0fe..5daf60e8a9 100644
--- a/app/assets/javascripts/admin/templates/components/themes-list.hbs
+++ b/app/assets/javascripts/admin/templates/components/themes-list.hbs
@@ -7,16 +7,16 @@
   </div>
 </div>
 
-<div class="themes-list-container" style="max-height: 485px;">
+<div class="themes-list-container" style="max-height: 450px;">
   {{#if hasThemes}}
     {{#if componentsTabActive}}
       {{#each themesList as |theme|}}
-        {{themes-list-item theme=theme}}
+        {{themes-list-item theme=theme navigateToTheme=(action "navigateToTheme" theme)}}
       {{/each}}
     {{else}}
       {{#if hasUserThemes}}
         {{#each userThemes as |theme|}}
-          {{themes-list-item theme=theme}}
+          {{themes-list-item theme=theme navigateToTheme=(action "navigateToTheme" theme)}}
         {{/each}}
 
         {{#if hasInactiveThemes}}
@@ -28,7 +28,7 @@
 
       {{#if hasInactiveThemes}}
         {{#each inactiveThemes as |theme|}}
-          {{themes-list-item theme=theme}}
+          {{themes-list-item theme=theme navigateToTheme=(action "navigateToTheme" theme)}}
         {{/each}}
       {{/if}}
     {{/if}}
diff --git a/app/assets/javascripts/admin/templates/customize-themes-index.hbs b/app/assets/javascripts/admin/templates/customize-themes-index.hbs
new file mode 100644
index 0000000000..307044d16e
--- /dev/null
+++ b/app/assets/javascripts/admin/templates/customize-themes-index.hbs
@@ -0,0 +1,11 @@
+<div class="themes-intro">
+  <h1>{{I18n "admin.customize.theme.themes_intro"}}</h1>
+  <div class="external-resources">
+    {{#each externalResources as |resource|}}
+      <a href={{resource.link}} class="external-link" target="_blank">
+        {{d-icon resource.icon}}
+        {{I18n resource.key}}
+      </a>
+    {{/each}}
+  </div>
+</div>
diff --git a/app/assets/javascripts/admin/templates/customize-themes-show.hbs b/app/assets/javascripts/admin/templates/customize-themes-show.hbs
index 1d490ade5e..9cb796793a 100644
--- a/app/assets/javascripts/admin/templates/customize-themes-show.hbs
+++ b/app/assets/javascripts/admin/templates/customize-themes-show.hbs
@@ -52,11 +52,11 @@
 
   <div class="control-unit">
     <div class="mini-title">{{i18n "admin.customize.theme.css_html"}}</div>
-    {{#if hasEditedFields}}
+    {{#if model.hasEditedFields}}
       <div class="description">{{i18n "admin.customize.theme.custom_sections"}}</div>
       <ul>
-        {{#each editedDescriptions as |desc|}}
-          <li>{{desc}}</li>
+        {{#each editedFieldsFormatted as |field|}}
+          <li>{{field}}</li>
         {{/each}}
       </ul>
     {{else}}
@@ -127,24 +127,17 @@
   {{#if availableChildThemes}}
     <div class="control-unit">
       <div class="mini-title">{{i18n "admin.customize.theme.theme_components"}}</div>
-      {{#unless model.childThemes.length}}
-      <div class="description">
-        <label class='checkbox-label'>
-          {{input type="checkbox" checked=allowChildThemes}}
-          {{i18n "admin.customize.theme.child_themes_check"}}
-        </label>
-      </div>
-      {{else}}
-      <ul class='removable-list'>
-        {{#each model.childThemes as |child|}}
-        <li>{{#link-to 'adminCustomizeThemes.show' child replace=true class='col'}}{{child.name}}{{/link-to}} {{d-button action="removeChildTheme" actionParam=child class="btn-small cancel-edit col" icon="times"}}</li>
-        {{/each}}
-      </ul>
-      {{/unless}}
+      {{#if model.childThemes.length}}
+        <ul class='removable-list'>
+          {{#each model.childThemes as |child|}}
+            <li>{{#link-to 'adminCustomizeThemes.show' child replace=true class='col'}}{{child.name}}{{/link-to}} {{d-button action="removeChildTheme" actionParam=child class="btn-small cancel-edit col" icon="times"}}</li>
+          {{/each}}
+        </ul>
+      {{/if}}
       {{#if selectableChildThemes}}
         <div class="description">
-          {{combo-box forceEscape=true filterable=true content=selectableChildThemes value=selectedChildThemeId}}
-          {{#d-button action="addChildTheme" icon="plus"}}{{i18n "admin.customize.theme.add"}}{{/d-button}}
+          {{combo-box forceEscape=true filterable=true content=selectableChildThemes value=selectedChildThemeId none="admin.customize.theme.select_component"}}
+          {{#d-button action="addChildTheme" icon="plus" disabled=addButtonDisabled class="add-component-button"}}{{i18n "admin.customize.theme.add"}}{{/d-button}}
         </div>
       {{/if}}
     </div>
diff --git a/app/assets/stylesheets/common/admin/customize.scss b/app/assets/stylesheets/common/admin/customize.scss
index ccd02cedf6..beefd8de9a 100644
--- a/app/assets/stylesheets/common/admin/customize.scss
+++ b/app/assets/stylesheets/common/admin/customize.scss
@@ -59,6 +59,18 @@
 }
 
 .admin-customize.admin-customize-themes {
+  .themes-intro {
+    float: right;
+    width: 34%;
+    margin-right: 20%;
+    margin-top: 60px;
+
+    .external-link {
+      display: block;
+      margin-bottom: 5px;
+    }
+  }
+
   .customize-themes-header {
     border-bottom: 1px solid $primary-low;
     padding-bottom: 8px;
@@ -158,12 +170,15 @@
     float: left;
     width: 70%;
   }
-
+  .add-component-button {
+    vertical-align: middle;
+  }
   .themes-list {
     border-right: 1px solid $primary-low;
     border-bottom: 1px solid $primary-low;
     float: left;
     width: 28%;
+    overflow: hidden;
   }
 
   .themes-list-header {
@@ -180,8 +195,7 @@
 
       &.active {
         font-weight: bold;
-        color: $secondary;
-        background-color: $tertiary;
+        color: $tertiary;
       }
 
       &:not(.active) {
@@ -195,18 +209,10 @@
   }
 
   .themes-list-container {
-    max-height: 485px;
-    overflow-y: auto;
+    overflow-y: scroll;
+    box-sizing: content-box;
+    width: 100%; /* overridden in javascript to hide scrollbar */
 
-    &::-webkit-scrollbar-track {
-      background-color: $secondary;
-    }
-    &::-webkit-scrollbar {
-      width: 5px;
-    }
-    &::-webkit-scrollbar-thumb {
-      background-color: $primary-low;
-    }
     .themes-list-item:last-child {
       border-bottom: none;
     }
@@ -216,22 +222,47 @@
       display: flex;
       border-left: 1px solid $primary-low;
 
-      &:not(.inactive-indicator):not(.active):hover {
+      &.inactive-indicator {
+        border-right: 0;
+        border-left: 0;
+        font-weight: bold;
+        color: $primary-medium;
+
+        span.empty {
+          padding-left: 5px;
+          padding-top: 15px;
+        }
+      }
+      &:not(.inactive-indicator):not(.selected):hover {
         background-color: $tertiary-low;
         .component {
           border-color: $primary-low-mid;
         }
       }
-      &.active {
+
+      &.selected {
         color: $secondary;
         background-color: $tertiary;
         .fa {
           color: inherit;
         }
       }
+      &:not(.selected) {
+        .broken-indicator {
+          color: $danger;
+        }
+        .fa {
+          opacity: 0.7;
+        }
+        .default-indicator {
+          color: $success;
+        }
+      }
+
       .light-grey-icon {
         color: $primary-medium;
       }
+
       .info {
         overflow: hidden;
         font-weight: bold;
@@ -253,6 +284,9 @@
         font-size: $font-down-1;
         align-items: baseline;
 
+        .others-count:hover {
+          text-decoration: underline;
+        }
         .component {
           display: flex;
           padding: 3px 5px 3px 5px;
@@ -262,37 +296,17 @@
           margin-bottom: 5px;
         }
       }
-      &:not(.active) {
-        .broken-indicator {
-          color: $danger;
-        }
 
-        .default-indicator {
-          color: $success;
-        }
-      }
-
-      a {
+      .inner-wrapper {
         padding: 10px;
-      }
-
-      &.inactive-indicator {
-        border-right: 0;
-        border-left: 0;
-        font-weight: bold;
-        color: $primary-medium;
-
-        span.empty {
-          padding-left: 5px;
-          padding-top: 15px;
-        }
+        cursor: pointer;
       }
 
       span.empty {
         padding: 3px 10px 3px 10px;
       }
 
-      a,
+      .inner-wrapper,
       span.empty {
         color: inherit;
         width: 100%;
diff --git a/config/locales/client.en.yml b/config/locales/client.en.yml
index df1eb640bd..c9508a605b 100644
--- a/config/locales/client.en.yml
+++ b/config/locales/client.en.yml
@@ -3191,7 +3191,6 @@ en:
         import: "Import"
         delete: "Delete"
         delete_confirm: "Delete this theme?"
-        about: "Modify CSS stylesheets and HTML headers on the site. Add a customization to start."
         color: "Color"
         opacity: "Opacity"
         copy: "Copy"
@@ -3214,6 +3213,10 @@ en:
           components: "Components"
           theme_name: "Theme name"
           component_name: "Component name"
+          themes_intro: "Select an existing theme or create a new one to get started"
+          beginners_guide_title: "Beginner’s guide to using Discourse Themes"
+          developers_guide_title: "Developer’s guide to Discourse Themes"
+          browse_themes: "Browse community themes"
           import_theme: "Import Theme"
           customize_desc: "Customize:"
           title: "Themes"
@@ -3245,6 +3248,7 @@ en:
           default_theme_tooltip: "This theme is the site's default theme"
           updates_available_tooltip: "Updates are available for this theme"
           and_x_more: "and {{count}} more."
+          collapse: Collapse
           uploads: "Uploads"
           no_uploads: "You can upload assets associated with your theme such as fonts and images"
           add_upload: "Add Upload"
@@ -3256,7 +3260,10 @@ en:
             no_overwrite: "Invalid variable name. Must not overwrite an existing variable."
             must_be_unique: "Invalid variable name. Must be unique."
           upload: "Upload"
-          child_themes_check: "Theme includes other child themes"
+          select_component: "Select a component..."
+          unsaved_changes_alert: "You haven't saved your changes yet, do you want to discard them and move on?"
+          discard: "Discard"
+          stay: "Stay"
           css_html: "Custom CSS/HTML"
           edit_css_html: "Edit CSS/HTML"
           edit_css_html_help: "You have not edited any CSS or HTML"
diff --git a/test/javascripts/admin/components/themes-list-item-test.js.es6 b/test/javascripts/admin/components/themes-list-item-test.js.es6
index da7eda3c6b..c08f1805b5 100644
--- a/test/javascripts/admin/components/themes-list-item-test.js.es6
+++ b/test/javascripts/admin/components/themes-list-item-test.js.es6
@@ -62,7 +62,7 @@ componentTest("with children", {
   beforeEach() {
     this.set(
       "theme",
-      Theme.create({ name: "Test", childThemes: childrenList })
+      Theme.create({ name: "Test", childThemes: childrenList, default: true })
     );
   },