first commit

src/components/CalculatorMode.jsx

@@ -0,0 +1,23 @@
+import { Select } from 'antd';
+
+export default function CalculatorMode({ value, onChange }) {
+    return (
+        <div className="form-row">
+            <label htmlFor="calculator-mode" className="form-label">
+                Calculate
+            </label>
+            <Select
+                id="calculator-mode"
+                value={value}
+                onChange={onChange}
+                size="large"
+                style={{ width: '100%' }}
+                options={[
+                    { value: 'shooting-interval', label: 'Shooting interval' },
+                    { value: 'clip-length', label: 'Clip length' },
+                    { value: 'event-duration', label: 'Event duration' },
+                ]}
+            />
+        </div>
+    );
+}