diff --git a/Gruntfile.js b/Gruntfile.js
index c42bf529d..6cec5e6ec 100644
--- a/Gruntfile.js
+++ b/Gruntfile.js
@@ -113,7 +113,7 @@ module.exports = grunt => {
         tasks: ['exec:build-protobuf'],
       },
       sass: {
-        files: ['./stylesheets/*.scss'],
+        files: ['./stylesheets/*.scss', './stylesheets/**/*.scss'],
         tasks: ['sass'],
       },
       transpile: {
diff --git a/stylesheets/_modules.scss b/stylesheets/_modules.scss
index 97dc97c29..c19668e35 100644
--- a/stylesheets/_modules.scss
+++ b/stylesheets/_modules.scss
@@ -11006,30 +11006,15 @@ button.module-image__border-overlay:focus {
   display: flex;
 }
 .module-group-v2-join-dialog__button {
-  @include button-reset;
-  @include font-body-1-bold;
-
   // Start flex basis at zero so text width doesn't affect layout. We want the buttons
   //   evenly distributed.
   flex: 1 1 0px;
 
-  border-radius: 4px;
-
-  padding: 8px;
-  padding-left: 15px;
-  padding-right: 15px;
-
-  @include button-primary;
-
   &:not(:first-of-type) {
     margin-left: 16px;
   }
 }
 
-.module-group-v2-join-dialog__button--secondary {
-  @include button-secondary;
-}
-
 // Module: Progress Dialog
 
 .module-progress-dialog {
diff --git a/stylesheets/components/Button.scss b/stylesheets/components/Button.scss
new file mode 100644
index 000000000..c7fadd621
--- /dev/null
+++ b/stylesheets/components/Button.scss
@@ -0,0 +1,109 @@
+// Copyright 2021 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+.module-Button {
+  @mixin focus-box-shadow($inner-color, $outer-color) {
+    &:focus {
+      box-shadow: 0 0 0 1px $inner-color, 0 0 0 4px $outer-color;
+    }
+  }
+
+  @mixin hover-and-active-states($background-color, $mix-color) {
+    &:hover:not(:disabled) {
+      background: mix($background-color, $mix-color, 85%);
+    }
+    &:active:not(:disabled) {
+      background: mix($background-color, $mix-color, 75%);
+    }
+  }
+
+  @include button-reset;
+  @include font-body-1-bold;
+
+  border-radius: 4px;
+  padding: 8px 16px;
+  text-align: center;
+  user-select: none;
+
+  @include keyboard-mode {
+    @include focus-box-shadow($color-white, $ultramarine-ui-light);
+  }
+
+  @include dark-keyboard-mode {
+    @include focus-box-shadow($color-black, $ultramarine-brand-light);
+  }
+
+  &--primary {
+    $color: $color-white;
+    $background-color: $ultramarine-ui-light;
+
+    color: $color;
+    background: $background-color;
+
+    &:disabled {
+      color: fade-out($color, 0.4);
+      background: fade-out($background-color, 0.6);
+    }
+
+    @include light-theme {
+      @include hover-and-active-states($background-color, $color-black);
+    }
+
+    @include dark-theme {
+      @include hover-and-active-states($background-color, $color-white);
+    }
+  }
+
+  &--secondary {
+    @include light-theme {
+      $color: $color-gray-90;
+      $background-color: $color-gray-05;
+
+      color: $color;
+      background: $background-color;
+
+      &:disabled {
+        color: $color-black-alpha-40;
+        background: fade-out($background-color, 0.6);
+      }
+
+      @include hover-and-active-states($background-color, $color-black);
+    }
+
+    @include dark-theme {
+      $color: $color-gray-05;
+      $background-color: $color-gray-65;
+
+      color: $color;
+      background: $background-color;
+
+      &:disabled {
+        color: $color-white-alpha-20;
+        background: fade-out($background-color, 0.6);
+      }
+
+      @include hover-and-active-states($background-color, $color-white);
+    }
+  }
+
+  &--destructive {
+    $color: $color-white;
+    $background-color: $color-accent-red;
+
+    color: $color;
+    background: $background-color;
+
+    &:disabled {
+      color: fade-out($color, 0.4);
+      background: fade-out($background-color, 0.6);
+    }
+
+    @include light-theme {
+      @include hover-and-active-states($background-color, $color-black);
+    }
+
+    @include dark-theme {
+      @include hover-and-active-states($background-color, $color-white);
+    }
+  }
+}
diff --git a/stylesheets/manifest.scss b/stylesheets/manifest.scss
index 499a67643..b4d853898 100644
--- a/stylesheets/manifest.scss
+++ b/stylesheets/manifest.scss
@@ -1,4 +1,4 @@
-// Copyright 2014-2020 Signal Messenger, LLC
+// Copyright 2014-2021 Signal Messenger, LLC
 // SPDX-License-Identifier: AGPL-3.0-only
 
 // Global Settings, Variables, and Mixins
@@ -7,7 +7,7 @@
 @import 'mixins';
 @import 'global';
 
-// Components
+// Old style: components
 @import 'progress';
 @import 'modal';
 @import 'debugLog';
@@ -16,12 +16,15 @@
 @import 'emoji';
 @import 'settings';
 
-// Build the main view
+// Old style: main view
 @import 'index';
 @import 'conversation';
 
-// New CSS
+// Old style: modules
 @import 'modules';
 
-// Installer
+// Old style: installer
 @import 'options';
+
+// New style: components
+@import './components/Button.scss';
diff --git a/ts/components/Button.stories.tsx b/ts/components/Button.stories.tsx
new file mode 100644
index 000000000..b9efb228d
--- /dev/null
+++ b/ts/components/Button.stories.tsx
@@ -0,0 +1,59 @@
+// Copyright 2021 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import React from 'react';
+import { storiesOf } from '@storybook/react';
+import { action } from '@storybook/addon-actions';
+
+import { Button, ButtonVariant } from './Button';
+
+const story = storiesOf('Components/Button', module);
+
+story.add('Kitchen sink', () => (
+  <>
+    <p>
+      <Button onClick={action('onClick')} variant={ButtonVariant.Primary}>
+        Hello world
+      </Button>
+    </p>
+    <p>
+      <Button
+        onClick={action('onClick')}
+        variant={ButtonVariant.Primary}
+        disabled
+      >
+        Hello world
+      </Button>
+    </p>
+
+    <p>
+      <Button onClick={action('onClick')} variant={ButtonVariant.Secondary}>
+        Hello world
+      </Button>
+    </p>
+    <p>
+      <Button
+        onClick={action('onClick')}
+        variant={ButtonVariant.Secondary}
+        disabled
+      >
+        Hello world
+      </Button>
+    </p>
+
+    <p>
+      <Button onClick={action('onClick')} variant={ButtonVariant.Destructive}>
+        Hello world
+      </Button>
+    </p>
+    <p>
+      <Button
+        onClick={action('onClick')}
+        variant={ButtonVariant.Destructive}
+        disabled
+      >
+        Hello world
+      </Button>
+    </p>
+  </>
+));
diff --git a/ts/components/Button.tsx b/ts/components/Button.tsx
new file mode 100644
index 000000000..596902d64
--- /dev/null
+++ b/ts/components/Button.tsx
@@ -0,0 +1,55 @@
+// Copyright 2021 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import React, { MouseEventHandler, ReactNode } from 'react';
+import classNames from 'classnames';
+
+import { assert } from '../util/assert';
+
+export enum ButtonVariant {
+  Primary,
+  Secondary,
+  Destructive,
+}
+
+type PropsType = {
+  children: ReactNode;
+  className?: string;
+  disabled?: boolean;
+  onClick: MouseEventHandler<HTMLButtonElement>;
+  variant?: ButtonVariant;
+};
+
+const VARIANT_CLASS_NAMES = new Map<ButtonVariant, string>([
+  [ButtonVariant.Primary, 'module-Button--primary'],
+  [ButtonVariant.Secondary, 'module-Button--secondary'],
+  [ButtonVariant.Destructive, 'module-Button--destructive'],
+]);
+
+export const Button = React.forwardRef<HTMLButtonElement, PropsType>(
+  (
+    {
+      children,
+      className,
+      disabled = false,
+      onClick,
+      variant = ButtonVariant.Primary,
+    },
+    ref
+  ) => {
+    const variantClassName = VARIANT_CLASS_NAMES.get(variant);
+    assert(variantClassName, '<Button> variant not found');
+
+    return (
+      <button
+        className={classNames('module-Button', variantClassName, className)}
+        disabled={disabled}
+        onClick={onClick}
+        ref={ref}
+        type="button"
+      >
+        {children}
+      </button>
+    );
+  }
+);
diff --git a/ts/components/GroupV2JoinDialog.tsx b/ts/components/GroupV2JoinDialog.tsx
index d89aa7ff4..8199e0c18 100644
--- a/ts/components/GroupV2JoinDialog.tsx
+++ b/ts/components/GroupV2JoinDialog.tsx
@@ -6,6 +6,7 @@ import classNames from 'classnames';
 import { LocalizerType } from '../types/Util';
 import { Avatar } from './Avatar';
 import { Spinner } from './Spinner';
+import { Button, ButtonVariant } from './Button';
 
 import { PreJoinConversationType } from '../state/ducks/conversations';
 
@@ -90,30 +91,30 @@ export const GroupV2JoinDialog = React.memo((props: PropsType) => {
       </div>
       <div className="module-group-v2-join-dialog__prompt">{promptString}</div>
       <div className="module-group-v2-join-dialog__buttons">
-        <button
+        <Button
           className={classNames(
             'module-group-v2-join-dialog__button',
             'module-group-v2-join-dialog__button--secondary'
           )}
           disabled={isWorking}
-          type="button"
           onClick={wrappedClose}
+          variant={ButtonVariant.Secondary}
         >
           {i18n('cancel')}
-        </button>
-        <button
+        </Button>
+        <Button
           className="module-group-v2-join-dialog__button"
           disabled={isWorking}
           ref={focusRef}
-          type="button"
           onClick={wrappedJoin}
+          variant={ButtonVariant.Primary}
         >
           {isJoining ? (
             <Spinner size="20px" svgSize="small" direction="on-avatar" />
           ) : (
             joinString
           )}
-        </button>
+        </Button>
       </div>
     </div>
   );