diff --git a/samples/calc-01/index.css b/samples/calc-01/index.css
index 6c885dd..94fe2e2 100644
--- a/samples/calc-01/index.css
+++ b/samples/calc-01/index.css
@@ -149,12 +149,32 @@ body {
   pointer-events: none;
 }
 
-.toolbar {
-  display: flex;
-  justify-content: space-between;
-  align-items: flex-start;
-  gap: 14px;
+.topbar {
   margin-top: 14px;
+  display: grid;
+  grid-template-columns: minmax(120px, 148px) minmax(132px, 160px) 1fr minmax(72px, 88px) minmax(108px, 128px) minmax(72px, 88px);
+  gap: 10px;
+  align-items: stretch;
+}
+
+.topbar-cell,
+.topbar-status {
+  min-height: 70px;
+  background: rgba(6, 10, 16, 0.18);
+  border: 1px solid rgba(255, 255, 255, 0.06);
+  border-radius: 16px;
+  padding: 10px;
+  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.05);
+}
+
+.topbar-label,
+.mode-select > span {
+  display: block;
+  margin-bottom: 6px;
+  font-size: 11px;
+  color: #d9e1ec;
+  text-transform: uppercase;
+  letter-spacing: 0.12em;
 }
 
 .status {
@@ -163,6 +183,7 @@ body {
   gap: 8px;
   color: #edf2fa;
   font-size: 12px;
+  align-content: center;
 }
 
 .pill {
@@ -175,11 +196,33 @@ body {
 .mode-select {
   display: grid;
   gap: 6px;
-  min-width: 148px;
+  min-width: 0;
   font-size: 12px;
-  color: #d9e1ec;
-  text-transform: uppercase;
-  letter-spacing: 0.08em;
+}
+
+.mode-cell select {
+  width: 100%;
+}
+
+.const-buttons {
+  display: grid;
+  grid-template-columns: repeat(2, minmax(0, 1fr));
+  gap: 8px;
+}
+
+.action-cell {
+  display: flex;
+  align-items: stretch;
+}
+
+.action-cell > button,
+.const-buttons > button {
+  width: 100%;
+}
+
+.topbar-status {
+  display: flex;
+  align-items: center;
 }
 
 select,
@@ -225,17 +268,17 @@ select {
 
 .functions-grid {
   grid-template-columns: repeat(4, minmax(0, 1fr));
-  grid-template-rows: repeat(5, 56px);
+  grid-template-rows: repeat(4, 56px);
 }
 
 .numbers-grid {
   grid-template-columns: repeat(3, minmax(0, 1fr));
-  grid-template-rows: repeat(5, 56px);
+  grid-template-rows: repeat(4, 56px);
 }
 
 .operators-grid {
   grid-template-columns: repeat(2, minmax(0, 1fr));
-  grid-template-rows: repeat(5, 56px);
+  grid-template-rows: repeat(4, 56px);
 }
 
 .key-spacer {
@@ -299,6 +342,12 @@ button:active {
   line-height: 1.5;
 }
 
+@media (max-width: 980px) {
+  .topbar {
+    grid-template-columns: repeat(3, minmax(0, 1fr));
+  }
+}
+
 @media (max-width: 860px) {
   .keyboard-layout {
     grid-template-columns: 1fr;
@@ -320,19 +369,14 @@ button:active {
     align-items: flex-start;
   }
 
-  .toolbar {
-    flex-direction: column;
-  }
-
-  .mode-select {
-    min-width: 0;
-    width: 100%;
+  .topbar {
+    grid-template-columns: 1fr;
   }
 
   .functions-grid,
   .numbers-grid,
   .operators-grid {
-    grid-template-rows: repeat(5, 52px);
+    grid-template-rows: repeat(4, 52px);
   }
 }
 
diff --git a/samples/calc-01/index.html b/samples/calc-01/index.html
index 34a9e6e..242e047 100644
--- a/samples/calc-01/index.html
+++ b/samples/calc-01/index.html
@@ -25,20 +25,29 @@
 
       <input id="input" class="hidden-input" type="text" autocomplete="off" aria-hidden="true" tabindex="-1">
 
-      <div class="toolbar">
-        <div class="status">
-          <div class="pill">inputValue: <span id="inputValueLabel"></span></div>
-          <div class="pill">isEditing: <span id="editingLabel"></span></div>
-        </div>
-
-        <label class="mode-select">
-          <span>Angle</span>
+      <div class="topbar">
+        <label class="topbar-cell mode-select mode-cell">
+          <span>mode</span>
           <select id="angleMode">
             <option value="deg">Degrees</option>
             <option value="rad">Radians</option>
             <option value="grad">Grads</option>
           </select>
         </label>
+
+        <div class="topbar-cell consts-cell">
+          <div class="topbar-label">consts</div>
+          <div class="const-buttons" id="constButtons"></div>
+        </div>
+
+        <div class="topbar-status status">
+          <div class="pill">inputValue: <span id="inputValueLabel"></span></div>
+          <div class="pill">isEditing: <span id="editingLabel"></span></div>
+        </div>
+
+        <div class="topbar-cell action-cell" id="deleteButton"></div>
+        <div class="topbar-cell action-cell" id="backspaceButton"></div>
+        <div class="topbar-cell action-cell" id="escapeButton"></div>
       </div>
 
       <div class="keyboard-layout">
diff --git a/samples/calc-01/index.js b/samples/calc-01/index.js
index 302a5f9..6b71b9e 100644
--- a/samples/calc-01/index.js
+++ b/samples/calc-01/index.js
@@ -12,12 +12,6 @@ const angleMode = document.getElementById('angleMode');
 
 const keyLayouts = {
   functions: [
-    [
-      { type: 'command', value: 'pi', label: 'π', className: 'key-function' },
-      { type: 'command', value: 'e', label: 'e', className: 'key-function' },
-      null,
-      null,
-    ],
     [
       { type: 'command', value: 'sqrt', label: 'sqrt', className: 'key-function' },
       { type: 'command', value: 'pow', label: 'y^x', className: 'key-function' },
@@ -44,7 +38,6 @@ const keyLayouts = {
     ],
   ],
   numbers: [
-    [null, null, null],
     [
       { type: 'input', value: '7', label: '7', className: 'key-number' },
       { type: 'input', value: '8', label: '8', className: 'key-number' },
@@ -67,13 +60,9 @@ const keyLayouts = {
     ],
   ],
   operators: [
-    [
-      { type: 'command', value: 'clear', label: 'del', className: 'key-danger' },
-      { type: 'action', value: 'escape', label: 'esc', className: 'key-danger' },
-    ],
     [
       { type: 'command', value: 'div', label: '/', className: 'key-operator' },
-      { type: 'command', value: 'drop', label: 'back', className: 'key-operator' },
+      null,
     ],
     [
       { type: 'command', value: 'mul', label: '*', className: 'key-operator' },
@@ -90,6 +79,16 @@ const keyLayouts = {
   ],
 };
 
+const topButtons = {
+  consts: [
+    { type: 'command', value: 'pi', label: 'π', className: 'key-function' },
+    { type: 'command', value: 'e', label: 'e', className: 'key-function' },
+  ],
+  del: { type: 'command', value: 'clear', label: 'del', className: 'key-danger' },
+  backspace: { type: 'action', value: 'backspace', label: 'backspace', className: 'key-operator' },
+  escape: { type: 'action', value: 'escape', label: 'esc', className: 'key-danger' },
+};
+
 let stackCursor = null;
 let isMovingStackItem = false;
 let stackSnapshotBeforeMove = null;
@@ -128,6 +127,16 @@ function pressKey(key) {
   render();
 }
 
+function handleBackspaceAction() {
+  if (calc.isEditing) {
+    editXWithKey('Backspace');
+    render();
+    return;
+  }
+
+  execute('drop');
+}
+
 function createButton(cell) {
   if (!cell) {
     const spacer = document.createElement('div');
@@ -146,9 +155,15 @@ function createButton(cell) {
       pressKey(cell.value);
       return;
     }
-    if (cell.type === 'action' && cell.value === 'escape') {
-      handleEscapeAction();
-      return;
+    if (cell.type === 'action') {
+      if (cell.value === 'escape') {
+        handleEscapeAction();
+        return;
+      }
+      if (cell.value === 'backspace') {
+        handleBackspaceAction();
+        return;
+      }
     }
     execute(cell.value);
   });
@@ -589,6 +604,10 @@ angleMode.addEventListener('change', (event) => {
 renderKeyLayout(document.getElementById('functionsButtons'), keyLayouts.functions);
 renderKeyLayout(document.getElementById('numbersButtons'), keyLayouts.numbers);
 renderKeyLayout(document.getElementById('operatorsButtons'), keyLayouts.operators);
+renderKeyLayout(document.getElementById('constButtons'), [topButtons.consts]);
+document.getElementById('deleteButton').appendChild(createButton(topButtons.del));
+document.getElementById('backspaceButton').appendChild(createButton(topButtons.backspace));
+document.getElementById('escapeButton').appendChild(createButton(topButtons.escape));
 
 render();
 focusScreen();
diff --git a/samples/calc-01/visual.txt b/samples/calc-01/visual.txt
index 4732b1a..2ab62bd 100644
--- a/samples/calc-01/visual.txt
+++ b/samples/calc-01/visual.txt
@@ -1,7 +1,15 @@
-┌───────────── Functions ────────────┬──── Numbers ────┬─── Operators ───┐
-| consts |        |      |           |   |   |         | del | esc       |
-| sqrt   | y^x    | x²   | 1/x       | 7 | 8 | 9       | /   | backspace |
-| log    | ln     |      | %         | 4 | 5 | 6       | *   |           |
-| sin    | cos    | tan  |           | 1 | 2 | 3       | -   | Enter     |
-| asin   | acos   | atan |           | 0 | . | +/-     | +   | Enter     |
-└────────────────────────────────────┴─────────────────┴─────────────────┘
+┌──────────────────────────────────────────────────────────────────────────────┐
+| T:                                                                           |
+| Z:                                                                           |
+| Y:                                                                           |
+| X:                                                                           |
+└──────────────────────────────────────────────────────────────────────────────┘
+┌──────────────────────────────────────────────────────────────────────────────┐
+| mode   | consts |                                   | del | backspace | esc  |
+└──────────────────────────────────────────────────────────────────────────────┘
+┌───────────── Functions ───────────────────┬───── Numbers ─────┬─  Operators ─┐
+| sqrt   | y^x    | x²   | 1/x              | 7 | 8 | 9         | / |          |
+| log    | ln     |      | %                | 4 | 5 | 6         | * |          |
+| sin    | cos    | tan  |                  | 1 | 2 | 3         | - | Enter    |
+| asin   | acos   | atan |                  | 0 | . | +/-       | + | Enter    |
+└───────────────────────────────────────────┴───────────────────┴──────────────┘