diff --git a/.gitignore b/.gitignore
index 44bcd428..8b457db9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,3 +5,4 @@ dist/
 npm-debug.log*
 yarn-debug.log*
 yarn-error.log*
+.vscode
diff --git a/src/assets/fonts/RobotoMono-Bold.woff b/src/assets/fonts/RobotoMono-Bold.woff
new file mode 100644
index 00000000..780aa1b5
Binary files /dev/null and b/src/assets/fonts/RobotoMono-Bold.woff differ
diff --git a/src/assets/fonts/RobotoMono-Regular.woff b/src/assets/fonts/RobotoMono-Regular.woff
new file mode 100644
index 00000000..8cb9e6fd
Binary files /dev/null and b/src/assets/fonts/RobotoMono-Regular.woff differ
diff --git a/src/assets/fonts/inconsolata-bold.woff b/src/assets/fonts/inconsolata-bold.woff
deleted file mode 100644
index b149e95f..00000000
Binary files a/src/assets/fonts/inconsolata-bold.woff and /dev/null differ
diff --git a/src/assets/fonts/inconsolata.woff b/src/assets/fonts/inconsolata.woff
deleted file mode 100644
index f6233210..00000000
Binary files a/src/assets/fonts/inconsolata.woff and /dev/null differ
diff --git a/src/components/ButtonBar.vue b/src/components/ButtonBar.vue
index d53bd69a..c9f06b5f 100644
--- a/src/components/ButtonBar.vue
+++ b/src/components/ButtonBar.vue
@@ -20,17 +20,15 @@
 </template>
 
 <script>
-import { mapState, mapActions } from 'vuex';
+import { mapState, mapMutations } from 'vuex';
 
 export default {
   computed: mapState('layout', [
     'showNavigationBar',
-    'showEditor',
     'showSidePreview',
-    'showSideBar',
     'showStatusBar',
   ]),
-  methods: mapActions('layout', [
+  methods: mapMutations('layout', [
     'toggleNavigationBar',
     'toggleEditor',
     'toggleSidePreview',
@@ -61,7 +59,6 @@ export default {
   width: 26px;
   height: 26px;
   padding: 2px;
-  border-radius: 3px;
   margin: 3px 0;
 
   &:hover {
diff --git a/src/components/Editor.vue b/src/components/Editor.vue
index a9030c90..c6513285 100644
--- a/src/components/Editor.vue
+++ b/src/components/Editor.vue
@@ -1,16 +1,16 @@
 <template>
   <div class="editor">
-    <pre class="editor__inner markdown-highlighting" :style="{ 'padding-left': editorPadding + 'px', 'padding-right': editorPadding + 'px' }"></pre>
+    <pre class="editor__inner markdown-highlighting" :style="{'padding-left': styles.editorPadding + 'px', 'padding-right': styles.editorPadding + 'px'}"></pre>
   </div>
 </template>
 
 
 <script>
-import { mapState } from 'vuex';
+import { mapGetters } from 'vuex';
 
 export default {
-  computed: mapState('layout', [
-    'editorPadding',
+  computed: mapGetters('layout', [
+    'styles',
   ]),
 };
 </script>
diff --git a/src/components/Explorer.vue b/src/components/Explorer.vue
index a5c8f753..ee40efda 100644
--- a/src/components/Explorer.vue
+++ b/src/components/Explorer.vue
@@ -1,18 +1,122 @@
 <template>
-  <div class="explorer">
+  <div class="explorer flex flex--column">
     <div class="side-title">
-      <div class="side-title__text">
-        Explorer
-      </div>
+      <button class="side-title__button side-title__button--right button" @click="toggleExplorer(false)">
+        <icon-close></icon-close>
+      </button>
+      <button class="side-title__button button" @click="newItem()">
+        <icon-file-plus></icon-file-plus>
+      </button>
+      <button class="side-title__button button" @click="newItem(true)">
+        <icon-folder-plus></icon-folder-plus>
+      </button>
+      <button class="side-title__button button" @click="editItem()">
+        <icon-pen></icon-pen>
+      </button>
+      <button class="side-title__button button" @click="deleteItem()">
+        <icon-delete></icon-delete>
+      </button>
+    </div>
+    <div class="explorer__tree" :class="{'explorer__tree--new-item': !newChildNode.isNil}" tabindex="0">
+      <explorer-node :node="rootNode" :depth="0"></explorer-node>
     </div>
   </div>
 </template>
 
 <script>
+import { mapState, mapGetters, mapMutations } from 'vuex';
+import ExplorerNode from './ExplorerNode';
+import emptyFile from '../data/emptyFile';
+import emptyFolder from '../data/emptyFolder';
+
 export default {
+  components: {
+    ExplorerNode,
+  },
+  computed: {
+    ...mapState('explorer', [
+      'newChildNode',
+    ]),
+    ...mapGetters('explorer', [
+      'rootNode',
+    ]),
+  },
+  methods: {
+    ...mapMutations('explorer', [
+      'setSelectedId',
+    ]),
+    ...mapMutations('layout', [
+      'toggleExplorer',
+    ]),
+    newItem(isFolder) {
+      const parentId = this.$store.getters['explorer/selectedNodeFolder'].item.id;
+      this.$store.dispatch('explorer/openNode', parentId);
+      this.$store.commit('explorer/setNewItem', {
+        ...isFolder ? emptyFolder() : emptyFile(),
+        parentId,
+      });
+    },
+    editItem() {
+      const selectNode = this.$store.getters['explorer/selectedNode'];
+      this.$store.commit('explorer/setEditingId', selectNode.item.id);
+    },
+    deleteItem() {
+      // const selectNode = this.$store.getters['explorer/selectedNode'];
+      // switch (this.node.item.type) {
+      //   case 'file':
+      //   default:
+      //     this.$store.commit('files/setCurrentId', id);
+      //     break;
+      //   case 'folder':
+      //     this.$store.commit('explorer/toggleOpenNode', id);
+      //     break;
+      // }
+    },
+  },
+  created() {
+    this.$store.watch(
+      () => this.$store.getters['files/current'].id,
+      (currentFileId) => {
+        this.setSelectedId(currentFileId);
+      }, {
+        immediate: true,
+      });
+  },
 };
 </script>
 
 <style lang="scss">
-@import 'common/variables.scss';
+.explorer,
+.explorer__tree {
+  height: 100%;
+}
+
+.side-title {
+  height: 44px;
+  line-height: 44px;
+  padding: 4px 8px 0;
+  background-color: rgba(0, 0, 0, 0.1);
+}
+
+.side-title__button {
+  width: 36px;
+  padding: 6px;
+  display: inline-block;
+  background-color: transparent;
+  opacity: 0.75;
+
+  /* prevent from seeing wrapped buttons */
+  margin-bottom: 20px;
+
+  &:active,
+  &:focus,
+  &:hover {
+    opacity: 1;
+    background-color: rgba(0, 0, 0, 0.1);
+  }
+}
+
+.side-title__button--right {
+  float: right;
+}
 </style>
diff --git a/src/components/ExplorerItem.vue b/src/components/ExplorerItem.vue
deleted file mode 100644
index 9ada47d4..00000000
--- a/src/components/ExplorerItem.vue
+++ /dev/null
@@ -1,13 +0,0 @@
-<template>
-  <div class="explorer-item">
-  </div>
-</template>
-
-<script>
-export default {
-};
-</script>
-
-<style lang="scss">
-@import 'common/variables.scss';
-</style>
diff --git a/src/components/ExplorerNode.vue b/src/components/ExplorerNode.vue
new file mode 100644
index 00000000..3dfd9bf8
--- /dev/null
+++ b/src/components/ExplorerNode.vue
@@ -0,0 +1,172 @@
+<template>
+  <div class="explorer-node" :class="{'explorer-node--selected': selected, 'explorer-node--open': open}">
+    <div v-if="editing" class="explorer-node__item-editor" :class="['explorer-node__item-editor--' + node.item.type]" :style="{'padding-left': leftPadding}">
+      <input type="text" class="text-input" v-focus @blur="submitEdit()" @keyup.enter="submitEdit()" @keyup.esc="submitEdit(true)" v-model="editingNodeName">
+    </div>
+    <div v-else-if="!node.isRoot" class="explorer-node__item" :class="['explorer-node__item--' + node.item.type]" :style="{'padding-left': leftPadding}" @click="select(node.item.id)">
+      {{node.item.name}}
+    </div>
+    <div v-if="node.isFolder && open">
+      <explorer-node v-for="node in node.folders" :key="node.item.id" :node="node" :depth="depth + 1"></explorer-node>
+      <div v-if="newChild" class="explorer-node__new-child" :class="['explorer-node__new-child--' + newChild.item.type]" :style="{'padding-left': childLeftPadding}">
+        <input type="text" class="text-input" v-focus @blur="submitNewChild()" @keyup.enter="submitNewChild()" @keyup.esc="submitNewChild(true)" v-model.trim="newChildName">
+      </div>
+      <explorer-node v-for="node in node.files" :key="node.item.id" :node="node" :depth="depth + 1"></explorer-node>
+    </div>
+  </div>
+</template>
+
+<script>
+import utils from '../services/utils';
+import defaultContent from '../data/defaultContent.md';
+
+export default {
+  name: 'explorer-node',
+  props: ['node', 'depth'],
+  directives: {
+    focus: {
+      inserted(el) {
+        el.focus();
+      },
+    },
+  },
+  data: () => ({
+    editingValue: '',
+  }),
+  computed: {
+    leftPadding() {
+      return `${this.depth * 15}px`;
+    },
+    childLeftPadding() {
+      return `${(this.depth + 1) * 15}px`;
+    },
+    selected() {
+      return this.$store.getters['explorer/selectedNode'] === this.node;
+    },
+    editing() {
+      return this.$store.getters['explorer/editingNode'] === this.node;
+    },
+    open() {
+      return this.$store.state.explorer.openNodes[this.node.item.id] || this.node.isRoot;
+    },
+    newChild() {
+      return this.$store.getters['explorer/newChildNodeParent'] === this.node
+        && this.$store.state.explorer.newChildNode;
+    },
+    newChildName: {
+      get() {
+        return this.$store.state.explorer.newChildNode.item.name;
+      },
+      set(value) {
+        this.$store.commit('explorer/setNewItemName', value && value.slice(0, 250));
+      },
+    },
+    editingNodeName: {
+      get() {
+        return this.$store.getters['explorer/editingNode'].item.name;
+      },
+      set(value) {
+        this.editingValue = value.trim();
+      },
+    },
+  },
+  methods: {
+    select(id) {
+      this.$store.commit('explorer/setSelectedId', id);
+      if (this.node.isFolder) {
+        this.$store.commit('explorer/toggleOpenNode', id);
+      } else {
+        this.$store.commit('files/setCurrentId', id);
+      }
+    },
+    submitNewChild(cancel) {
+      const newChildNode = this.$store.state.explorer.newChildNode;
+      if (!cancel && newChildNode.item.name) {
+        const id = utils.uid();
+        if (newChildNode.isFolder) {
+          this.$store.commit('folders/setItem', {
+            ...newChildNode.item,
+            id,
+          });
+        } else {
+          const contentId = utils.uid();
+          this.$store.commit('contents/setItem', {
+            id: contentId,
+            text: defaultContent,
+          });
+          this.$store.commit('files/setItem', {
+            ...newChildNode.item,
+            id,
+            contentId,
+          });
+        }
+        this.select(id);
+      }
+      this.$store.commit('explorer/setNewItem', null);
+    },
+    submitEdit(cancel) {
+      const id = this.$store.getters['explorer/editingNode'].item.id;
+      const value = this.editingValue;
+      if (!cancel && id && value) {
+        this.$store.commit('files/patchItem', {
+          id,
+          name: value.slice(0, 250),
+        });
+      }
+      this.$store.commit('explorer/setEditingId', null);
+    },
+  },
+};
+</script>
+
+<style lang="scss">
+$item-font-size: 14px;
+
+.explorer-node__item {
+  cursor: pointer;
+  font-size: $item-font-size;
+  overflow: hidden;
+  white-space: nowrap;
+  text-overflow: ellipsis;
+
+  .explorer-node--selected > & {
+    background-color: rgba(0, 0, 0, 0.2);
+
+    .explorer__tree:focus & {
+      background-color: #39f;
+      color: #fff;
+    }
+  }
+
+  .explorer__tree--new-item & {
+    opacity: 0.33;
+  }
+}
+
+.explorer-node__item--folder,
+.explorer-node__item-editor--folder,
+.explorer-node__new-child--folder {
+  &::before {
+    content: '▸';
+    position: absolute;
+    margin-left: -13px;
+
+    .explorer-node--open > & {
+      content: '▾';
+    }
+  }
+}
+
+$new-child-height: 25px;
+
+.explorer-node__item-editor,
+.explorer-node__new-child {
+  padding: 1px 10px;
+
+  .text-input {
+    font-size: $item-font-size;
+    padding: 2px;
+    height: $new-child-height;
+  }
+}
+</style>
diff --git a/src/components/Layout.vue b/src/components/Layout.vue
index 7e24ea09..345c7d62 100644
--- a/src/components/Layout.vue
+++ b/src/components/Layout.vue
@@ -1,29 +1,29 @@
 <template>
   <div class="layout">
     <div class="layout__panel flex flex--row">
-      <div class="layout__panel layout__panel--explorer" v-show="showExplorer" :style="{ width: explorerWidth + 'px' }">
+      <div class="layout__panel layout__panel--explorer" v-show="styles.showExplorer" :style="{ width: constants.explorerWidth + 'px' }">
         <explorer></explorer>
       </div>
-      <div class="layout__panel flex flex--column" :style="{ width: innerWidth + 'px' }">
-        <div class="layout__panel layout__panel--navigation-bar" v-show="showNavigationBar || !showEditor" :style="{ height: navigationBarHeight + 'px' }">
+      <div class="layout__panel flex flex--column" :style="{ width: styles.innerWidth + 'px' }">
+        <div class="layout__panel layout__panel--navigation-bar" v-show="styles.showNavigationBar" :style="{ height: constants.navigationBarHeight + 'px' }">
           <navigation-bar></navigation-bar>
         </div>
-        <div class="layout__panel flex flex--row" :style="{ height: innerHeight + 'px' }">
-          <div class="layout__panel layout__panel--editor" v-show="showEditor" :style="{ width: editorWidth + 'px', 'font-size': fontSize + 'px' }">
+        <div class="layout__panel flex flex--row" :style="{ height: styles.innerHeight + 'px' }">
+          <div class="layout__panel layout__panel--editor" v-show="styles.showEditor" :style="{ width: styles.editorWidth + 'px', 'font-size': styles.fontSize + 'px' }">
             <editor></editor>
           </div>
-          <div class="layout__panel layout__panel--button-bar" v-show="showEditor" :style="{ width: buttonBarWidth + 'px' }">
+          <div class="layout__panel layout__panel--button-bar" v-show="styles.showEditor" :style="{ width: constants.buttonBarWidth + 'px' }">
             <button-bar></button-bar>
           </div>
-          <div class="layout__panel layout__panel--preview" v-show="showSidePreview || !showEditor" :style="{ width: previewWidth + 'px', 'font-size': fontSize + 'px' }">
+          <div class="layout__panel layout__panel--preview" v-show="styles.showPreview" :style="{ width: styles.previewWidth + 'px', 'font-size': styles.fontSize + 'px' }">
             <preview></preview>
           </div>
         </div>
-        <div class="layout__panel layout__panel--status-bar" v-show="showStatusBar" :style="{ height: statusBarHeight + 'px' }">
+        <div class="layout__panel layout__panel--status-bar" v-show="styles.showStatusBar" :style="{ height: constants.statusBarHeight + 'px' }">
           <status-bar></status-bar>
         </div>
       </div>
-      <div class="layout__panel layout__panel--side-bar" v-show="showSideBar" :style="{ width: sideBarWidth + 'px' }">
+      <div class="layout__panel layout__panel--side-bar" v-show="styles.showSideBar" :style="{ width: constants.sideBarWidth + 'px' }">
         <side-bar></side-bar>
       </div>
     </div>
@@ -31,7 +31,7 @@
 </template>
 
 <script>
-import { mapState, mapActions } from 'vuex';
+import { mapState, mapGetters, mapMutations } from 'vuex';
 import NavigationBar from './NavigationBar';
 import ButtonBar from './ButtonBar';
 import StatusBar from './StatusBar';
@@ -40,7 +40,6 @@ import SideBar from './SideBar';
 import Editor from './Editor';
 import Preview from './Preview';
 import editorSvc from '../services/editorSvc';
-import constants from '../services/constants';
 
 export default {
   components: {
@@ -52,33 +51,23 @@ export default {
     Editor,
     Preview,
   },
-  computed: mapState('layout', {
-    explorerWidth: 'explorerWidth',
-    sideBarWidth: 'sideBarWidth',
-    navigationBarHeight: 'navigationBarHeight',
-    buttonBarWidth: 'buttonBarWidth',
-    statusBarHeight: 'statusBarHeight',
-    showEditor: 'showEditor',
-    showSidePreview: 'showSidePreview',
-    showNavigationBar: 'showNavigationBar',
-    showStatusBar: 'showStatusBar',
-    showSideBar: 'showSideBar',
-    showExplorer: 'showExplorer',
-    fontSize: 'fontSize',
-    innerWidth: 'innerWidth',
-    innerHeight: 'innerHeight',
-    previewWidth: 'previewWidth',
-    editorWidth: 'editorWidth',
-  }),
+  computed: {
+    ...mapState('layout', [
+      'constants',
+    ]),
+    ...mapGetters('layout', [
+      'styles',
+    ]),
+  },
   methods: {
-    ...mapActions('layout', [
-      'updateStyle',
+    ...mapMutations('layout', [
+      'updateBodySize',
     ]),
     saveSelection: () => editorSvc.saveSelection(true),
   },
   created() {
-    this.updateStyle();
-    window.addEventListener('resize', this.updateStyle);
+    this.updateBodySize();
+    window.addEventListener('resize', this.updateBodySize);
     window.addEventListener('keyup', this.saveSelection);
     window.addEventListener('mouseup', this.saveSelection);
     window.addEventListener('contextmenu', this.saveSelection);
@@ -106,10 +95,10 @@ export default {
           / (sectionDesc.tocDimension.height || 1);
         const editorScrollTop = sectionDesc.editorDimension.startOffset
           + (sectionDesc.editorDimension.height * posInSection);
-        editorElt.parentNode.scrollTop = editorScrollTop - constants.scrollOffset;
+        editorElt.parentNode.scrollTop = editorScrollTop;
         const previewScrollTop = sectionDesc.previewDimension.startOffset
           + (sectionDesc.previewDimension.height * posInSection);
-        previewElt.parentNode.scrollTop = previewScrollTop - constants.scrollOffset;
+        previewElt.parentNode.scrollTop = previewScrollTop;
         return true;
       });
     }
@@ -162,7 +151,7 @@ export default {
 }
 
 .layout__panel--explorer {
-  background-color: #ddd;
+  background-color: #dadada;
 }
 
 .layout__panel--button-bar,
diff --git a/src/components/NavigationBar.vue b/src/components/NavigationBar.vue
index ac9ed0b2..88a784d5 100644
--- a/src/components/NavigationBar.vue
+++ b/src/components/NavigationBar.vue
@@ -1,13 +1,13 @@
 <template>
-  <div class="navigation-bar" v-bind:class="{'navigation-bar--editor': showEditor}">
+  <div class="navigation-bar" v-bind:class="{'navigation-bar--editor': styles.showEditor}">
     <div class="navigation-bar__inner navigation-bar__inner--left navigation-bar__inner--button">
       <button class="navigation-bar__button button" @click="toggleExplorer()">
-        <icon-menu></icon-menu>
+        <icon-folder-multiple></icon-folder-multiple>
       </button>
     </div>
     <div class="navigation-bar__inner navigation-bar__inner--right navigation-bar__inner--button">
       <button class="navigation-bar__button button" @click="toggleExplorer()">
-        <icon-settings></icon-settings>
+        <icon-menu></icon-menu>
       </button>
     </div>
     <div class="navigation-bar__inner navigation-bar__inner--right flex flex--row">
@@ -15,7 +15,7 @@
         <div class="spinner"></div>
       </div>
       <div class="navigation-bar__title navigation-bar__title--fake text-input"></div>
-      <div class="navigation-bar__title navigation-bar__title--text text-input" v-bind:style="{maxWidth: titleMaxWidth + 'px'}">{{title}}</div>
+      <div class="navigation-bar__title navigation-bar__title--text text-input" v-bind:style="{maxWidth: styles.titleMaxWidth + 'px'}">{{title}}</div>
       <input class="navigation-bar__title navigation-bar__title--input text-input" v-bind:class="{'navigation-bar__title--focus': titleFocus, 'navigation-bar__title--scrolling': titleScrolling}" v-bind:style="{width: titleWidth + 'px'}" @focus="editTitle(true)" @blur="editTitle(false)" @keyup.enter="submitTitle()" @keyup.esc="submitTitle(true)" v-on:mouseenter="titleHover = true" v-on:mouseleave="titleHover = false" v-model="title">
     </div>
     <div class="navigation-bar__inner navigation-bar__inner--edit-buttons">
@@ -60,7 +60,7 @@
 </template>
 
 <script>
-import { mapState, mapActions } from 'vuex';
+import { mapGetters, mapMutations } from 'vuex';
 import editorSvc from '../services/editorSvc';
 import animationSvc from '../services/animationSvc';
 
@@ -72,19 +72,18 @@ export default {
     titleHover: false,
   }),
   computed: {
-    ...mapState('layout', {
-      showEditor: 'showEditor',
-      titleMaxWidth: 'titleMaxWidth',
-    }),
+    ...mapGetters('layout', [
+      'styles',
+    ]),
     titleWidth() {
       if (!this.mounted) {
         return 0;
       }
       this.titleFakeElt.textContent = this.title;
-      const width = this.titleFakeElt.getBoundingClientRect().width + 1; // 1px for the caret
-      return width < this.titleMaxWidth
+      const width = this.titleFakeElt.getBoundingClientRect().width + 2; // 2px for the caret
+      return width < this.styles.titleMaxWidth
         ? width
-        : this.titleMaxWidth;
+        : this.styles.titleMaxWidth;
     },
     titleScrolling() {
       const result = this.titleHover && !this.titleFocus;
@@ -106,7 +105,7 @@ export default {
     },
   },
   methods: {
-    ...mapActions('layout', [
+    ...mapMutations('layout', [
       'toggleExplorer',
       'toggleSideBar',
     ]),
@@ -120,7 +119,7 @@ export default {
       } else {
         const title = this.title.trim();
         if (title) {
-          this.$store.dispatch('files/patchCurrent', { name: title });
+          this.$store.dispatch('files/patchCurrent', { name: title.slice(0, 250) });
         } else {
           this.title = this.$store.getters['files/current'].name;
         }
@@ -161,6 +160,10 @@ export default {
 
 .navigation-bar__inner--left {
   float: left;
+
+  &.navigation-bar__inner--button {
+    margin-right: 15px;
+  }
 }
 
 .navigation-bar__inner--right {
@@ -176,9 +179,16 @@ export default {
 }
 
 .navigation-bar__button {
-  display: inline-block;
   width: 34px;
   padding: 6px;
+
+  /* prevent from seeing wrapped buttons */
+  margin-bottom: 20px;
+
+  .navigation-bar__inner--button & {
+    padding: 7px;
+    width: 38px;
+  }
 }
 
 .navigation-bar__title,
@@ -186,7 +196,7 @@ export default {
   display: inline-block;
   color: $navbar-color;
   background-color: transparent;
-  font-weight: 400;
+  font-size: 22px;
 }
 
 .navigation-bar__title--input,
@@ -235,7 +245,7 @@ export default {
 }
 
 .navigation-bar__spinner {
-  margin: 10px 5px 0;
+  margin: 10px 5px 0 15px;
   color: rgba(255, 255, 255, 0.33);
 }
 
diff --git a/src/components/Preview.vue b/src/components/Preview.vue
index 89b003c5..ce576dd0 100644
--- a/src/components/Preview.vue
+++ b/src/components/Preview.vue
@@ -1,19 +1,19 @@
 <template>
   <div class="preview">
-    <div class="preview__inner" :style="{ 'padding-left': previewPadding + 'px', 'padding-right': previewPadding + 'px' }">
+    <div class="preview__inner" :style="{ 'padding-left': styles.previewPadding + 'px', 'padding-right': styles.previewPadding + 'px' }">
     </div>
   </div>
 </template>
 
 
 <script>
-import { mapState } from 'vuex';
+import { mapGetters } from 'vuex';
 
 const appUri = `${window.location.protocol}//${window.location.host}`;
 
 export default {
-  computed: mapState('layout', [
-    'previewPadding',
+  computed: mapGetters('layout', [
+    'styles',
   ]),
   mounted() {
     this.$el.addEventListener('click', (evt) => {
@@ -45,4 +45,17 @@ export default {
   margin: 0;
   padding: 0 1035px 360px;
 }
+
+.preview__inner > :first-child {
+  & > h1,
+  & > h2,
+  & > h3,
+  & > h4,
+  & > h5,
+  & > h6 {
+    &:first-child {
+      margin-top: 0;
+    }
+  }
+}
 </style>
diff --git a/src/components/StatusBar.vue b/src/components/StatusBar.vue
index 41b0dcaf..777ca31b 100644
--- a/src/components/StatusBar.vue
+++ b/src/components/StatusBar.vue
@@ -1,8 +1,8 @@
 <template>
   <div class="stat-panel panel no-overflow">
-    <div class="stat-panel__block stat-panel__block--left" v-if="showEditor">
+    <div class="stat-panel__block stat-panel__block--left" v-if="styles.showEditor">
       <span class="stat-panel__block-name">
-        Text
+        Markdown
         <small v-show="textSelection">(selection)</small>
       </span>
       <span v-for="stat in textStats" :key="stat.id">
@@ -23,7 +23,7 @@
 </template>
 
 <script>
-import { mapState } from 'vuex';
+import { mapGetters } from 'vuex';
 import editorSvc from '../services/editorSvc';
 import editorEngineSvc from '../services/editorEngineSvc';
 import utils from '../services/utils';
@@ -54,9 +54,9 @@ export default {
       new Stat('paragraphs', '\\S.*'),
     ],
   }),
-  computed: mapState('layout', {
-    showEditor: 'showEditor',
-  }),
+  computed: mapGetters('layout', [
+    'styles',
+  ]),
   created() {
     editorSvc.$on('sectionList', () => this.computeText());
     editorSvc.$on('selectionRange', () => this.computeText());
diff --git a/src/components/common/app.scss b/src/components/common/app.scss
index 53f224c6..221fcbae 100644
--- a/src/components/common/app.scss
+++ b/src/components/common/app.scss
@@ -38,10 +38,11 @@ textarea {
 
 .text-input {
   display: block;
+  font-variant-ligatures: no-common-ligatures;
   width: 100%;
   height: 36px;
   padding: 3px 12px;
-  font-size: 22px;
+  font-size: inherit;
   line-height: 1.5;
   color: inherit;
   background-color: #fff;
@@ -57,7 +58,7 @@ textarea {
   height: 36px;
   padding: 3px 12px;
   margin-bottom: 0;
-  font-size: 22px;
+  font-size: inherit;
   font-weight: 400;
   line-height: 1.4;
   overflow: hidden;
@@ -106,13 +107,3 @@ textarea {
   flex-direction: column;
 }
 
-.side-title {
-  height: 44px;
-  line-height: 44px;
-  padding: 0 10px;
-  background-color: #ccc;
-}
-
-.side-title__text {
-  text-transform: uppercase;
-}
diff --git a/src/components/common/fonts.scss b/src/components/common/fonts.scss
index 9cf4049f..97697051 100644
--- a/src/components/common/fonts.scss
+++ b/src/components/common/fonts.scss
@@ -27,15 +27,15 @@
 }
 
 @font-face {
-  font-family: 'Inconsolata';
+  font-family: 'Roboto Mono';
   font-style: normal;
   font-weight: 400;
-  src: url('../assets/fonts/inconsolata.woff') format('woff');
+  src: url('../assets/fonts/RobotoMono-Regular.woff') format('woff');
 }
 
 @font-face {
-  font-family: 'Inconsolata';
+  font-family: 'Roboto Mono';
   font-style: normal;
   font-weight: 600;
-  src: url('../assets/fonts/inconsolata-bold.woff') format('woff');
+  src: url('../assets/fonts/RobotoMono-Bold.woff') format('woff');
 }
diff --git a/src/components/common/variables.scss b/src/components/common/variables.scss
index a2981e42..701c6d6e 100644
--- a/src/components/common/variables.scss
+++ b/src/components/common/variables.scss
@@ -1,8 +1,8 @@
 $font-family-main: Lato, 'Helvetica Neue', Helvetica, sans-serif;
-$font-family-monospace: Inconsolata, 'Lucida Sans Typewriter', 'Lucida Console', monaco, Courrier, monospace;
+$font-family-monospace: 'Roboto Mono', 'Lucida Sans Typewriter', 'Lucida Console', monaco, Courrier, monospace;
 $line-height-base: 1.67;
 $line-height-title: 1.33;
-$font-size-monospace: 0.95em;
+$font-size-monospace: 0.85em;
 $code-bg: rgba(0, 0, 0, 0.05);
 $code-border-radius: 2px;
 $link-color: #4a80cf;
@@ -10,7 +10,7 @@ $border-radius-base: 2px;
 $hr-color: rgba(128, 128, 128, 0.2);
 $navbar-color: rgba(255, 255, 255, 0.67);
 $navbar-hover-color: #fff;
-$navbar-hover-background: #484848;
+$navbar-hover-background: rgba(255, 255, 255, 0.1);
 
 $editor-color: rgba(0, 0, 0, 0.8);
 $editor-color-light: rgba(0, 0, 0, 0.28);
diff --git a/src/data/defaultContent.md b/src/data/defaultContent.md
new file mode 100644
index 00000000..77309c15
--- /dev/null
+++ b/src/data/defaultContent.md
@@ -0,0 +1,4 @@
+
+
+
+> Written with [StackEdit](https://stackedit.io/).
diff --git a/src/data/emptyContent.js b/src/data/emptyContent.js
index 4a298adb..ecf1b588 100644
--- a/src/data/emptyContent.js
+++ b/src/data/emptyContent.js
@@ -1,4 +1,5 @@
 export default () => ({
+  id: null,
   type: 'content',
   state: {},
   text: '\n',
diff --git a/src/data/emptyFile.js b/src/data/emptyFile.js
index 75dab695..9035933e 100644
--- a/src/data/emptyFile.js
+++ b/src/data/emptyFile.js
@@ -1,6 +1,7 @@
 export default () => ({
+  id: null,
   type: 'file',
   name: '',
-  folderId: null,
+  parentId: null,
   contentId: null,
 });
diff --git a/src/data/emptyFolder.js b/src/data/emptyFolder.js
new file mode 100644
index 00000000..8419d417
--- /dev/null
+++ b/src/data/emptyFolder.js
@@ -0,0 +1,6 @@
+export default () => ({
+  id: null,
+  type: 'folder',
+  name: '',
+  parentId: null,
+});
diff --git a/src/icons/Close.vue b/src/icons/Close.vue
new file mode 100644
index 00000000..6337271f
--- /dev/null
+++ b/src/icons/Close.vue
@@ -0,0 +1,5 @@
+<template>
+  <svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" baseProfile="full" class="icon" width="100%" height="100%" viewBox="0 0 24.00 24.00" enable-background="new 0 0 24.00 24.00" xml:space="preserve">
+    <path d="M19,6.41L17.59,5L12,10.59L6.41,5L5,6.41L10.59,12L5,17.59L6.41,19L12,13.41L17.59,19L19,17.59L13.41,12L19,6.41Z" />
+  </svg>
+</template>
diff --git a/src/icons/Delete.vue b/src/icons/Delete.vue
new file mode 100644
index 00000000..872908ff
--- /dev/null
+++ b/src/icons/Delete.vue
@@ -0,0 +1,5 @@
+<template>
+  <svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" baseProfile="full" class="icon" width="100%" height="100%" viewBox="0 0 24.00 24.00" enable-background="new 0 0 24.00 24.00" xml:space="preserve">
+    <path d="M19,4H15.5L14.5,3H9.5L8.5,4H5V6H19M6,19C6,20.1 6.9,21 8,21H16C17.1,21 18,20.1 18,19V7H6V19Z" />
+  </svg>
+</template>
diff --git a/src/icons/FilePlus.vue b/src/icons/FilePlus.vue
new file mode 100644
index 00000000..9932fe10
--- /dev/null
+++ b/src/icons/FilePlus.vue
@@ -0,0 +1,5 @@
+<template>
+  <svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" baseProfile="full" class="icon" width="100%" height="100%" viewBox="0 0 24.00 24.00" enable-background="new 0 0 24.00 24.00" xml:space="preserve">
+    <path d="M13,9H18.5L13,3.5V9M6,2H14L20,8V20C20,21.1 19.1,22 18,22H6C4.89,22 4,21.1 4,20V4C4,2.89 4.89,2 6,2M11,15V12H9V15H6V17H9V20H11V17H14V15H11Z" />
+  </svg>
+</template>
diff --git a/src/icons/FolderMultiple.vue b/src/icons/FolderMultiple.vue
new file mode 100644
index 00000000..0e42e38f
--- /dev/null
+++ b/src/icons/FolderMultiple.vue
@@ -0,0 +1,5 @@
+<template>
+  <svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" baseProfile="full" class="icon" width="100%" height="100%" viewBox="0 0 24.00 24.00" enable-background="new 0 0 24.00 24.00" xml:space="preserve">
+    <path d="M22,4H14L12,2H6C4.9,2 4,2.9 4,4V16C4,17.1 4.9,18 6,18H22C23.1,18 24,17.1 24,16V6C24,4.9 23.1,4 22,4M2,6H0V11H0V20C0,21.1 0.9,22 2,22H20V20H2V6Z" />
+  </svg>
+</template>
diff --git a/src/icons/FolderPlus.vue b/src/icons/FolderPlus.vue
new file mode 100644
index 00000000..6c706ff8
--- /dev/null
+++ b/src/icons/FolderPlus.vue
@@ -0,0 +1,5 @@
+<template>
+  <svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" baseProfile="full" class="icon" width="100%" height="100%" viewBox="0 0 24.00 24.00" enable-background="new 0 0 24.00 24.00" xml:space="preserve">
+    <path d="M10,4L12,6H20C21.1,6 22,6.9 22,8V18C22,19.1 21.1,20 20,20H4C2.89,20 2,19.1 2,18V6C2,4.89 2.89,4 4,4H10M15,9V12H12V14H15V17H17V14H20V12H17V9H15Z" />
+  </svg>
+</template>
diff --git a/src/icons/Pen.vue b/src/icons/Pen.vue
new file mode 100644
index 00000000..2e97a1c1
--- /dev/null
+++ b/src/icons/Pen.vue
@@ -0,0 +1,5 @@
+<template>
+  <svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" baseProfile="full" class="icon" width="100%" height="100%" viewBox="0 0 24.00 24.00" enable-background="new 0 0 24.00 24.00" xml:space="preserve">
+    <path d="M20.71,7.04C21.1,6.65 21.1,6 20.71,5.63L18.37,3.29C18,2.9 17.35,2.9 16.96,3.29L15.12,5.12L18.87,8.87M3,17.25V21H6.75L17.81,9.93L14.06,6.18L3,17.25Z" />
+  </svg>
+</template>
diff --git a/src/icons/index.js b/src/icons/index.js
index b4b3e07e..894f5b28 100644
--- a/src/icons/index.js
+++ b/src/icons/index.js
@@ -17,6 +17,12 @@ import SidePreview from './SidePreview';
 import Eye from './Eye';
 import Menu from './Menu';
 import Settings from './Settings';
+import FilePlus from './FilePlus';
+import FolderPlus from './FolderPlus';
+import Delete from './Delete';
+import Close from './Close';
+import FolderMultiple from './FolderMultiple';
+import Pen from './Pen';
 
 Vue.component('iconFormatBold', FormatBold);
 Vue.component('iconFormatItalic', FormatItalic);
@@ -36,3 +42,9 @@ Vue.component('iconSidePreview', SidePreview);
 Vue.component('iconEye', Eye);
 Vue.component('iconMenu', Menu);
 Vue.component('iconSettings', Settings);
+Vue.component('iconFilePlus', FilePlus);
+Vue.component('iconFolderPlus', FolderPlus);
+Vue.component('iconDelete', Delete);
+Vue.component('iconClose', Close);
+Vue.component('iconFolderMultiple', FolderMultiple);
+Vue.component('iconPen', Pen);
diff --git a/src/services/constants.js b/src/services/constants.js
deleted file mode 100644
index 7dc3cbba..00000000
--- a/src/services/constants.js
+++ /dev/null
@@ -1,3 +0,0 @@
-export default {
-  scrollOffset: 0,
-};
diff --git a/src/services/editorSvc.js b/src/services/editorSvc.js
index 3deb2048..9a31725e 100644
--- a/src/services/editorSvc.js
+++ b/src/services/editorSvc.js
@@ -9,7 +9,6 @@ import markdownConversionSvc from './markdownConversionSvc';
 import markdownGrammarSvc from './markdownGrammarSvc';
 import sectionUtils from './sectionUtils';
 import extensionSvc from './extensionSvc';
-import constants from './constants';
 import animationSvc from './animationSvc';
 import editorEngineSvc from './editorEngineSvc';
 import store from '../store';
@@ -63,7 +62,7 @@ const editorSvc = Object.assign(new Vue(), { // Use a vue instance as an event b
   getObjectToScroll() {
     let elt = this.editorElt.parentNode;
     let dimensionKey = 'editorDimension';
-    if (!store.state.layout.showEditor) {
+    if (!store.getters['layout/styles'].showEditor) {
       elt = this.previewElt.parentNode;
       dimensionKey = 'previewDimension';
     }
@@ -426,10 +425,10 @@ const editorSvc = Object.assign(new Vue(), { // Use a vue instance as an event b
     let scrollerElt = this.previewElt.parentNode;
     const sectionDesc = anchorHash[anchor];
     if (sectionDesc) {
-      if (store.state.layout.showSidePreview || !store.state.layout.showEditor) {
+      if (store.getters['layout/styles'].showPreview) {
         scrollTop = sectionDesc.previewDimension.startOffset;
       } else {
-        scrollTop = sectionDesc.editorDimension.startOffset - constants.scrollOffset;
+        scrollTop = sectionDesc.editorDimension.startOffset;
         scrollerElt = this.editorElt.parentNode;
       }
     } else {
@@ -575,7 +574,7 @@ const editorSvc = Object.assign(new Vue(), { // Use a vue instance as an event b
 
     let newSectionList;
     let newSelectionRange;
-    const debouncedEditorChanged = debounce(() => {
+    const onEditorChanged = () => {
       if (this.sectionList !== newSectionList) {
         this.sectionList = newSectionList;
         this.$emit('sectionList', this.sectionList);
@@ -590,7 +589,8 @@ const editorSvc = Object.assign(new Vue(), { // Use a vue instance as an event b
         this.$emit('selectionRange', this.selectionRange);
       }
       this.saveContentState();
-    }, 10);
+    };
+    const debouncedEditorChanged = debounce(onEditorChanged, 10);
 
     editorEngineSvc.clEditor.selectionMgr.on('selectionChanged', (start, end, selectionRange) => {
       newSelectionRange = selectionRange;
@@ -685,9 +685,15 @@ const editorSvc = Object.assign(new Vue(), { // Use a vue instance as an event b
 
     editorEngineSvc.clEditor.on('contentChanged', (content, diffs, sectionList) => {
       newSectionList = sectionList;
-      debouncedEditorChanged();
+      if (instantPreview) {
+        onEditorChanged();
+      } else {
+        debouncedEditorChanged();
+      }
     });
 
+    this.$emit('inited');
+
     // scope.$watch('editorLayoutSvc.isEditorOpen', function (isOpen) {
     //   clEditorSvc.cledit.toggleEditable(isOpen)
     // })
@@ -736,12 +742,10 @@ const editorSvc = Object.assign(new Vue(), { // Use a vue instance as an event b
         immediate: true,
       });
 
-    store.watch(state => `${state.layout.editorWidth},${state.layout.previewWidth}`,
+    store.watch(() => `${store.getters['layout/styles'].editorWidth},${store.getters['layout/styles'].previewWidth}`,
       () => editorSvc.measureSectionDimensions(true));
-    store.watch(state => state.layout.showSidePreview,
+    store.watch(() => store.getters['layout/styles'].showSidePreview,
       showSidePreview => showSidePreview && editorSvc.measureSectionDimensions());
-
-    this.$emit('inited');
   },
 });
 
diff --git a/src/services/localDbSvc.js b/src/services/localDbSvc.js
index 97e967e7..c53e4879 100644
--- a/src/services/localDbSvc.js
+++ b/src/services/localDbSvc.js
@@ -118,6 +118,7 @@ export default {
       [
         store.state.contents,
         store.state.files,
+        store.state.folders,
       ].forEach(moduleState => Object.assign(storeItemMap, moduleState.itemMap));
       this.connection.createTx((tx) => {
         this.readAll(storeItemMap, tx, () => {
diff --git a/src/services/optional/scrollSync.js b/src/services/optional/scrollSync.js
index ee4ad011..b8d8060b 100644
--- a/src/services/optional/scrollSync.js
+++ b/src/services/optional/scrollSync.js
@@ -1,5 +1,4 @@
 import store from '../../store';
-import constants from '../constants';
 import animationSvc from '../animationSvc';
 import editorSvc from '../editorSvc';
 
@@ -34,9 +33,7 @@ function throttle(func, wait) {
 }
 
 const doScrollSync = () => {
-  const localSkipAnimation = skipAnimation
-    || !store.state.layout.showSidePreview
-    || !store.state.layout.showEditor;
+  const localSkipAnimation = skipAnimation || !store.getters['layout/styles'].showSidePreview;
   skipAnimation = false;
   if (!store.state.editor.scrollSync || !sectionDescList || sectionDescList.length === 0) {
     return;
@@ -45,12 +42,11 @@ const doScrollSync = () => {
   if (editorScrollTop < 0) {
     editorScrollTop = 0;
   }
-  let previewScrollTop = previewScrollerElt.scrollTop;
+  const previewScrollTop = previewScrollerElt.scrollTop;
   let scrollTo;
   if (isScrollEditor) {
     // Scroll the preview
     isScrollEditor = false;
-    editorScrollTop += constants.scrollOffset;
     sectionDescList.some((sectionDesc) => {
       if (editorScrollTop > sectionDesc.editorDimension.endOffset) {
         return false;
@@ -58,7 +54,7 @@ const doScrollSync = () => {
       const posInSection = (editorScrollTop - sectionDesc.editorDimension.startOffset)
         / (sectionDesc.editorDimension.height || 1);
       scrollTo = (sectionDesc.previewDimension.startOffset
-        + (sectionDesc.previewDimension.height * posInSection)) - constants.scrollOffset;
+        + (sectionDesc.previewDimension.height * posInSection));
       return true;
     });
     scrollTo = Math.min(
@@ -79,10 +75,9 @@ const doScrollSync = () => {
           isPreviewMoving = true;
         });
     }, localSkipAnimation ? 500 : 50);
-  } else if (!store.state.layout.showEditor || isScrollPreview) {
+  } else if (!store.getters['layout/styles'].showEditor || isScrollPreview) {
     // Scroll the editor
     isScrollPreview = false;
-    previewScrollTop += constants.scrollOffset;
     sectionDescList.some((sectionDesc) => {
       if (previewScrollTop > sectionDesc.previewDimension.endOffset) {
         return false;
@@ -90,7 +85,7 @@ const doScrollSync = () => {
       const posInSection = (previewScrollTop - sectionDesc.previewDimension.startOffset)
         / (sectionDesc.previewDimension.height || 1);
       scrollTo = (sectionDesc.editorDimension.startOffset
-        + (sectionDesc.editorDimension.height * posInSection)) - constants.scrollOffset;
+        + (sectionDesc.editorDimension.height * posInSection));
       return true;
     });
     scrollTo = Math.min(
@@ -119,7 +114,7 @@ let timeoutId;
 
 const forceScrollSync = () => {
   if (!isPreviewRefreshing) {
-    doScrollSync(!store.state.layout.showSidePreview);
+    doScrollSync();
   }
 };
 store.watch(state => state.editor.scrollSync, forceScrollSync);
@@ -135,7 +130,7 @@ editorSvc.$on('inited', () => {
     }
     isScrollEditor = true;
     isScrollPreview = false;
-    doScrollSync(!store.state.layout.showSidePreview);
+    doScrollSync();
   });
 
   previewScrollerElt.addEventListener('scroll', () => {
@@ -144,7 +139,7 @@ editorSvc.$on('inited', () => {
     }
     isScrollPreview = true;
     isScrollEditor = false;
-    doScrollSync(!store.state.layout.showSidePreview);
+    doScrollSync();
   });
 });
 
@@ -163,14 +158,15 @@ editorSvc.$on('previewText', () => {
   // Remove height property once the preview as been refreshed
   previewElt.style.removeProperty('height');
   // Assume the user is writing in the editor
-  isScrollEditor = store.state.layout.showEditor;
+  isScrollEditor = store.getters['layout/styles'].showEditor;
   // A preview scrolling event can occur if height is smaller
   timeoutId = setTimeout(() => {
     isPreviewRefreshing = false;
   }, 100);
 });
 
-store.watch(state => state.layout.showSidePreview,
+store.watch(
+  () => store.getters['layout/styles'].showSidePreview,
   (showSidePreview) => {
     if (showSidePreview) {
       isScrollEditor = true;
@@ -179,6 +175,12 @@ store.watch(state => state.layout.showSidePreview,
     }
   });
 
+store.watch(
+  () => store.getters['files/current'].id,
+  () => {
+    skipAnimation = true;
+  });
+
 editorSvc.$on('sectionDescMeasuredList', (sectionDescMeasuredList) => {
   sectionDescList = sectionDescMeasuredList;
   forceScrollSync();
diff --git a/src/services/syncSvc.js b/src/services/syncSvc.js
index b4e6ea0b..06a530d1 100644
--- a/src/services/syncSvc.js
+++ b/src/services/syncSvc.js
@@ -10,39 +10,35 @@ const ifNoId = cb => (obj) => {
   return cb();
 };
 
-// Watch file changing
-store.watch(
-  () => store.getters['files/current'].id,
-  () => Promise.resolve(store.getters['files/current'])
-    // If current file has no ID, get the most recent file
-    .then(ifNoId(() => store.getters['files/mostRecent']))
-    // If no ID, load the DB (we're booting)
-    .then(ifNoId(() => localDbSvc.sync()
-      // Retry
-      .then(() => store.getters['files/current'])
-      .then(ifNoId(() => store.getters['files/mostRecent'])),
-    ))
-    // Finally create a new file
-    .then(ifNoId(() => {
-      const contentId = utils.uid();
-      store.commit('contents/setItem', {
-        id: contentId,
-        text: welcomeFile,
-      });
-      const fileId = utils.uid();
-      store.commit('files/setItem', {
-        id: fileId,
-        name: 'Welcome file',
-        contentId,
-      });
-      return store.state.files.itemMap[fileId];
-    }))
-    .then((currentFile) => {
-      store.commit('files/setCurrentId', currentFile.id);
-      store.dispatch('files/patchCurrent', {}); // Update `updated` field to make it the mostRecent
-    }),
-  {
-    immediate: true,
-  });
+// Load the DB on boot
+localDbSvc.sync()
+  // Watch file changing
+  .then(() => store.watch(
+    () => store.getters['files/current'].id,
+    () => Promise.resolve(store.getters['files/current'])
+      // If current file has no ID, get the most recent file
+      .then(ifNoId(() => store.getters['files/mostRecent']))
+      // If still no ID, create a new file
+      .then(ifNoId(() => {
+        const contentId = utils.uid();
+        store.commit('contents/setItem', {
+          id: contentId,
+          text: welcomeFile,
+        });
+        const fileId = utils.uid();
+        store.commit('files/setItem', {
+          id: fileId,
+          name: 'Welcome file',
+          contentId,
+        });
+        return store.state.files.itemMap[fileId];
+      }))
+      .then((currentFile) => {
+        store.commit('files/setCurrentId', currentFile.id);
+        store.dispatch('files/patchCurrent', {}); // Update `updated` field to make it the mostRecent
+      }),
+    {
+      immediate: true,
+    }));
 
 utils.setInterval(() => localDbSvc.sync(), 1200);
diff --git a/src/store/index.js b/src/store/index.js
index 0e5a7bcc..fa2f3fc2 100644
--- a/src/store/index.js
+++ b/src/store/index.js
@@ -3,8 +3,10 @@ import Vue from 'vue';
 import Vuex from 'vuex';
 import contents from './modules/contents';
 import files from './modules/files';
+import folders from './modules/folders';
 import layout from './modules/layout';
 import editor from './modules/editor';
+import explorer from './modules/explorer';
 
 Vue.use(Vuex);
 
@@ -14,8 +16,10 @@ const store = new Vuex.Store({
   modules: {
     contents,
     files,
+    folders,
     layout,
     editor,
+    explorer,
   },
   strict: debug,
   plugins: debug ? [createLogger()] : [],
diff --git a/src/store/modules/explorer.js b/src/store/modules/explorer.js
new file mode 100644
index 00000000..4dadc219
--- /dev/null
+++ b/src/store/modules/explorer.js
@@ -0,0 +1,114 @@
+import Vue from 'vue';
+import emptyFile from '../../data/emptyFile';
+import emptyFolder from '../../data/emptyFolder';
+
+const setter = propertyName => (state, value) => {
+  state[propertyName] = value;
+};
+
+const collator = new Intl.Collator(undefined, { sensitivity: 'base' });
+const compare = (node1, node2) => collator.compare(node1.item.name, node2.item.name);
+
+class Node {
+  constructor(item, isFolder, isRoot) {
+    this.item = item;
+    this.isFolder = isFolder;
+    this.isRoot = isRoot;
+    if (isFolder) {
+      this.folders = [];
+      this.files = [];
+    }
+  }
+
+  sortChildren() {
+    if (this.isFolder) {
+      this.folders.sort(compare);
+      this.files.sort(compare);
+      this.folders.forEach(child => child.sortChildren());
+    }
+  }
+}
+
+const nilFileNode = new Node(emptyFile());
+nilFileNode.isNil = true;
+
+function getParent(node, getters) {
+  if (node === nilFileNode) {
+    return nilFileNode;
+  }
+  return getters.nodeMap[node.item.parentId] || getters.rootNode;
+}
+
+export default {
+  namespaced: true,
+  state: {
+    selectedId: null,
+    editingId: null,
+    newChildNode: nilFileNode,
+    openNodes: {},
+  },
+  getters: {
+    nodeStructure: (state, getters, rootState, rootGetters) => {
+      const nodeMap = {};
+      rootGetters['folders/items'].forEach((item) => {
+        nodeMap[item.id] = new Node(item, true);
+      });
+      rootGetters['files/items'].forEach((item) => {
+        nodeMap[item.id] = new Node(item);
+      });
+      const rootNode = new Node(emptyFolder(), true, true);
+      Object.keys(nodeMap).forEach((id) => {
+        const node = nodeMap[id];
+        let parentNode = nodeMap[node.item.parentId];
+        if (!parentNode || !parentNode.isFolder) {
+          parentNode = rootNode;
+        }
+        if (node.isFolder) {
+          parentNode.folders.push(node);
+        } else {
+          parentNode.files.push(node);
+        }
+      });
+      rootNode.sortChildren();
+      return {
+        nodeMap,
+        rootNode,
+      };
+    },
+    nodeMap: (state, getters) => getters.nodeStructure.nodeMap,
+    rootNode: (state, getters) => getters.nodeStructure.rootNode,
+    newChildNodeParent: (state, getters) => getParent(state.newChildNode, getters),
+    selectedNode: (state, getters) => getters.nodeMap[state.selectedId] || nilFileNode,
+    selectedNodeFolder: (state, getters) => {
+      const selectedNode = getters.selectedNode;
+      return selectedNode.item.type === 'folder'
+        ? selectedNode
+        : getParent(selectedNode, getters);
+    },
+    editingNode: (state, getters) => getters.nodeMap[state.editingId] || nilFileNode,
+  },
+  mutations: {
+    setSelectedId: setter('selectedId'),
+    setEditingId: setter('editingId'),
+    setNewItem(state, item) {
+      state.newChildNode = item ? new Node(item) : nilFileNode;
+    },
+    setNewItemName(state, name) {
+      state.newChildNode.item.name = name;
+    },
+    toggleOpenNode(state, id) {
+      Vue.set(state.openNodes, id, !state.openNodes[id]);
+    },
+  },
+  actions: {
+    openNode({ state, getters, commit, dispatch }, id) {
+      const node = getters.nodeMap[id];
+      if (node) {
+        if (node.isFolder && !state.openNodes[id]) {
+          commit('toggleOpenNode', id);
+        }
+        dispatch('openNode', node.item.parentId);
+      }
+    },
+  },
+};
diff --git a/src/store/modules/folders.js b/src/store/modules/folders.js
new file mode 100644
index 00000000..f53792d8
--- /dev/null
+++ b/src/store/modules/folders.js
@@ -0,0 +1,6 @@
+import moduleTemplate from './moduleTemplate';
+import empty from '../../data/emptyFolder';
+
+const module = moduleTemplate(empty);
+
+export default module;
diff --git a/src/store/modules/layout.js b/src/store/modules/layout.js
index fa933048..78fb0bb4 100644
--- a/src/store/modules/layout.js
+++ b/src/store/modules/layout.js
@@ -9,148 +9,135 @@ const setter = propertyName => (state, value) => {
   state[propertyName] = value;
 };
 
-const toggler = (propertyName, setterName) => ({ state, commit, dispatch }, show) => {
-  commit(setterName, show === undefined ? !state[propertyName] : show);
-  dispatch('updateStyle');
+const toggler = propertyName => (state, value) => {
+  state[propertyName] = value === undefined ? !state[propertyName] : value;
 };
 
 export default {
   namespaced: true,
   state: {
-    // Constants
-    explorerWidth: 280,
-    sideBarWidth: 280,
-    navigationBarHeight: 44,
-    buttonBarWidth: 30,
-    statusBarHeight: 20,
+    constants: {
+      explorerWidth: 250,
+      sideBarWidth: 280,
+      navigationBarHeight: 44,
+      buttonBarWidth: 30,
+      statusBarHeight: 20,
+    },
     // Configuration
     showNavigationBar: true,
     showEditor: true,
     showSidePreview: true,
     showStatusBar: true,
     showSideBar: false,
-    showExplorer: false,
+    showExplorer: true,
     editorWidthFactor: 1,
     fontSizeFactor: 1,
-    // Style
-    fontSize: 0,
-    innerWidth: 0,
-    innerHeight: 0,
-    editorWidth: 0,
-    editorPadding: 0,
-    previewWidth: 0,
-    previewPadding: 0,
-    titleMaxWidth: 0,
+    // Styles
+    bodyWidth: 0,
+    bodyHeight: 0,
   },
   mutations: {
-    setShowNavigationBar: setter('showNavigationBar'),
-    setShowEditor: setter('showEditor'),
-    setShowSidePreview: setter('showSidePreview'),
-    setShowStatusBar: setter('showStatusBar'),
-    setShowSideBar: setter('showSideBar'),
-    setShowExplorer: setter('showExplorer'),
+    toggleNavigationBar: toggler('showNavigationBar'),
+    toggleEditor: toggler('showEditor'),
+    toggleSidePreview: toggler('showSidePreview'),
+    toggleStatusBar: toggler('showStatusBar'),
+    toggleSideBar: toggler('showSideBar'),
+    toggleExplorer: toggler('showExplorer'),
     setEditorWidthFactor: setter('editorWidthFactor'),
     setFontSizeFactor: setter('fontSizeFactor'),
-    setFontSize: setter('fontSize'),
-    setInnerWidth: setter('innerWidth'),
-    setInnerHeight: setter('innerHeight'),
-    setEditorWidth: setter('editorWidth'),
-    setEditorPadding: setter('editorPadding'),
-    setPreviewWidth: setter('previewWidth'),
-    setPreviewPadding: setter('previewPadding'),
-    setTitleMaxWidth: setter('titleMaxWidth'),
+    updateBodySize: (state) => {
+      state.bodyWidth = document.body.clientWidth;
+      state.bodyHeight = document.body.clientHeight;
+    },
   },
-  actions: {
-    toggleNavigationBar: toggler('showNavigationBar', 'setShowNavigationBar'),
-    toggleEditor: toggler('showEditor', 'setShowEditor'),
-    toggleSidePreview: toggler('showSidePreview', 'setShowSidePreview'),
-    toggleStatusBar: toggler('showStatusBar', 'setShowStatusBar'),
-    toggleSideBar: toggler('showSideBar', 'setShowSideBar'),
-    toggleExplorer: toggler('showExplorer', 'setShowExplorer'),
-    updateStyle({ state, commit, dispatch }) {
-      const bodyWidth = document.body.clientWidth;
-      const bodyHeight = document.body.clientHeight;
+  getters: {
+    styles: (state) => {
+      const styles = {
+        showNavigationBar: !state.showEditor || state.showNavigationBar,
+        showStatusBar: state.showStatusBar,
+        showEditor: state.showEditor,
+        showSidePreview: state.showSidePreview && state.showEditor,
+        showPreview: state.showSidePreview || !state.showEditor,
+        showSideBar: state.showSideBar,
+        showExplorer: state.showExplorer,
+      };
 
-      const showNavigationBar = !state.showEditor || state.showNavigationBar;
-      let innerHeight = bodyHeight;
-      if (showNavigationBar) {
-        innerHeight -= state.navigationBarHeight;
-      }
-      if (state.showStatusBar) {
-        innerHeight -= state.statusBarHeight;
-      }
+      function computeStyles() {
+        styles.innerHeight = state.bodyHeight;
+        if (styles.showNavigationBar) {
+          styles.innerHeight -= state.constants.navigationBarHeight;
+        }
+        if (styles.showStatusBar) {
+          styles.innerHeight -= state.constants.statusBarHeight;
+        }
 
-      let innerWidth = bodyWidth;
-      if (state.showSideBar) {
-        innerWidth -= state.sideBarWidth;
-      }
-      if (state.showExplorer) {
-        innerWidth -= state.explorerWidth;
-      }
-      let doublePanelWidth = innerWidth - state.buttonBarWidth;
-      if (doublePanelWidth < editorMinWidth) {
-        if (state.showSideBar) {
-          dispatch('toggleSideBar', false);
+        styles.innerWidth = state.bodyWidth;
+        if (styles.showSideBar) {
+          styles.innerWidth -= state.constants.sideBarWidth;
+        }
+        if (styles.showExplorer) {
+          styles.innerWidth -= state.constants.explorerWidth;
+        }
+
+        let doublePanelWidth = styles.innerWidth - state.constants.buttonBarWidth;
+        if (doublePanelWidth < editorMinWidth) {
+          if (styles.showSideBar) {
+            styles.showSideBar = false;
+            computeStyles();
+            return;
+          }
+          if (styles.showExplorer) {
+            styles.showExplorer = false;
+            computeStyles();
+            return;
+          }
+          doublePanelWidth = editorMinWidth;
+        }
+
+        if (styles.showSidePreview && doublePanelWidth / 2 < editorMinWidth) {
+          styles.showSidePreview = false;
+          computeStyles();
           return;
         }
-        if (state.showExplorer) {
-          dispatch('toggleExplorer', false);
-          return;
+
+        styles.fontSize = 18;
+        styles.textWidth = 990;
+        if (doublePanelWidth < 1120) {
+          styles.fontSize -= 1;
+          styles.textWidth = 910;
         }
-        doublePanelWidth = editorMinWidth;
-      }
-      const splitPanel = state.showEditor && state.showSidePreview;
-      if (splitPanel && doublePanelWidth / 2 < editorMinWidth) {
-        dispatch('toggleSidePreview', false);
-        return;
+        if (doublePanelWidth < 1040) {
+          styles.textWidth = 830;
+        }
+        styles.textWidth *= state.editorWidthFactor;
+        if (doublePanelWidth < styles.textWidth) {
+          styles.textWidth = doublePanelWidth;
+        }
+        if (styles.textWidth < 640) {
+          styles.fontSize -= 1;
+        }
+        styles.fontSize *= state.fontSizeFactor;
+
+        const panelWidth = doublePanelWidth / 2;
+        styles.previewWidth = styles.showSidePreview ?
+          panelWidth :
+          styles.innerWidth;
+        styles.previewPadding = Math.max((styles.previewWidth - styles.textWidth) / 2, minPadding);
+        styles.editorWidth = styles.showSidePreview ?
+          panelWidth :
+          doublePanelWidth;
+        styles.editorPadding = Math.max((styles.editorWidth - styles.textWidth) / 2, minPadding);
+
+        styles.titleMaxWidth = styles.innerWidth - navigationBarSpaceWidth;
+        if (styles.showEditor) {
+          styles.titleMaxWidth -= navigationBarLeftWidth;
+        }
+        styles.titleMaxWidth = Math.min(styles.titleMaxWidth, maxTitleMaxWidth);
+        styles.titleMaxWidth = Math.max(styles.titleMaxWidth, minTitleMaxWidth);
       }
 
-      let fontSize = 18;
-      let textWidth = 990;
-      if (doublePanelWidth < 1120) {
-        fontSize -= 1;
-        textWidth = 910;
-      }
-      if (doublePanelWidth < 1040) {
-        textWidth = 830;
-      }
-      if (textWidth < 640) {
-        fontSize -= 1;
-      }
-      textWidth *= state.editorWidthFactor;
-      fontSize *= state.fontSizeFactor;
-
-      const panelWidth = doublePanelWidth / 2;
-      const previewWidth = splitPanel ?
-        panelWidth :
-        innerWidth;
-      let previewPadding = (previewWidth - textWidth) / 2;
-      if (previewPadding < minPadding) {
-        previewPadding = minPadding;
-      }
-      const editorWidth = splitPanel ?
-        panelWidth :
-        doublePanelWidth;
-      let editorPadding = (editorWidth - textWidth) / 2;
-      if (editorPadding < minPadding) {
-        editorPadding = minPadding;
-      }
-
-      let titleMaxWidth = innerWidth - navigationBarSpaceWidth;
-      if (state.showEditor) {
-        titleMaxWidth -= navigationBarLeftWidth;
-      }
-      titleMaxWidth = Math.min(titleMaxWidth, maxTitleMaxWidth);
-      titleMaxWidth = Math.max(titleMaxWidth, minTitleMaxWidth);
-
-      commit('setFontSize', fontSize);
-      commit('setInnerWidth', innerWidth);
-      commit('setInnerHeight', innerHeight);
-      commit('setPreviewWidth', previewWidth);
-      commit('setPreviewPadding', previewPadding);
-      commit('setEditorWidth', editorWidth);
-      commit('setEditorPadding', editorPadding);
-      commit('setTitleMaxWidth', titleMaxWidth);
+      computeStyles();
+      return styles;
     },
   },
 };