refactor: use a consistent classname prop and avoid children prop

I was using the FunctionComponent type for some component that do not
use children. So I change the type to VoidFunctionComponent to avoid
mistakes.
I also rename all the "classes" or "additionalClasses" props to
"className" to keep consistency between each components.

36 files changed, 270 insertions, 118 deletions

diff --git a/src/components/atoms/buttons/button-link.tsx b/src/components/atoms/buttons/button-link.tsx
index 47fe4b0..81229c8 100644
--- a/src/components/atoms/buttons/button-link.tsx
+++ b/src/components/atoms/buttons/button-link.tsx
@@ -2,7 +2,7 @@ import Link from 'next/link';
 import { FC } from 'react';
 import styles from './buttons.module.scss';
 
-type ButtonLinkProps = {
+export type ButtonLinkProps = {
   /**
    * ButtonLink accessible label.
    */
diff --git a/src/components/atoms/buttons/button.stories.tsx b/src/components/atoms/buttons/button.stories.tsx
index 9f4061b..1061d83 100644
--- a/src/components/atoms/buttons/button.stories.tsx
+++ b/src/components/atoms/buttons/button.stories.tsx
@@ -33,6 +33,19 @@ export default {
         required: true,
       },
     },
+    className: {
+      control: {
+        type: 'text',
+      },
+      description: 'Set additional classnames to the button wrapper.',
+      table: {
+        category: 'Styles',
+      },
+      type: {
+        name: 'string',
+        required: false,
+      },
+    },
     disabled: {
       control: {
         type: 'boolean',
diff --git a/src/components/atoms/buttons/button.tsx b/src/components/atoms/buttons/button.tsx
index ae4c894..b223046 100644
--- a/src/components/atoms/buttons/button.tsx
+++ b/src/components/atoms/buttons/button.tsx
@@ -3,9 +3,9 @@ import styles from './buttons.module.scss';
 
 export type ButtonProps = {
   /**
-   * Add additional classes to the button wrapper.
+   * Set additional classnames to the button wrapper.
    */
-  additionalClasses?: string;
+  className?: string;
   /**
    * Button accessible label.
    */
@@ -17,7 +17,7 @@ export type ButtonProps = {
   /**
    * Button kind. Default: secondary.
    */
-  kind?: 'primary' | 'secondary' | 'tertiary';
+  kind?: 'primary' | 'secondary' | 'tertiary' | 'neutral';
   /**
    * A callback function to handle click.
    */
@@ -38,7 +38,7 @@ export type ButtonProps = {
  * Use a button as call to action.
  */
 const Button: FC<ButtonProps> = ({
-  additionalClasses,
+  className = '',
   ariaLabel,
   children,
   disabled = false,
@@ -54,7 +54,7 @@ const Button: FC<ButtonProps> = ({
     <button
       type={type}
       disabled={disabled}
-      className={`${styles.btn} ${kindClass} ${shapeClass} ${additionalClasses}`}
+      className={`${styles.btn} ${kindClass} ${shapeClass} ${className}`}
       aria-label={ariaLabel}
       {...props}
     >
diff --git a/src/components/atoms/buttons/buttons.module.scss b/src/components/atoms/buttons/buttons.module.scss
index a1c3dba..87c92db 100644
--- a/src/components/atoms/buttons/buttons.module.scss
+++ b/src/components/atoms/buttons/buttons.module.scss
@@ -28,6 +28,10 @@
     cursor: wait;
   }
 
+  &--neutral {
+    background: inherit;
+  }
+
   &--primary {
     background: var(--color-primary);
     border: fun.convert-px(2) solid var(--color-bg);
diff --git a/src/components/atoms/forms/toggle.module.scss b/src/components/atoms/forms/toggle.module.scss
index 00e87a2..24b867e 100644
--- a/src/components/atoms/forms/toggle.module.scss
+++ b/src/components/atoms/forms/toggle.module.scss
@@ -6,10 +6,11 @@
 
   display: inline-flex;
   align-items: center;
+  width: 100%;
 }
 
 .title {
-  margin-right: var(--spacing-xs);
+  margin-right: auto;
 }
 
 .toggle {
diff --git a/src/components/atoms/forms/toggle.stories.tsx b/src/components/atoms/forms/toggle.stories.tsx
index 6e7323b..ea08694 100644
--- a/src/components/atoms/forms/toggle.stories.tsx
+++ b/src/components/atoms/forms/toggle.stories.tsx
@@ -34,6 +34,20 @@ export default {
         required: true,
       },
     },
+    labelSize: {
+      control: {
+        type: 'select',
+      },
+      description: 'The label size.',
+      options: ['medium', 'small'],
+      table: {
+        category: 'Options',
+      },
+      type: {
+        name: 'string',
+        required: false,
+      },
+    },
     name: {
       control: {
         type: 'text',
diff --git a/src/components/atoms/forms/toggle.tsx b/src/components/atoms/forms/toggle.tsx
index e8e8c0f..7ef40ed 100644
--- a/src/components/atoms/forms/toggle.tsx
+++ b/src/components/atoms/forms/toggle.tsx
@@ -1,9 +1,16 @@
-import { FC, ReactElement } from 'react';
+import { ReactNode, VFC } from 'react';
+import Label, { LabelProps } from './label';
 import styles from './toggle.module.scss';
 
 export type ToggleChoices = {
-  left: ReactElement | string;
-  right: ReactElement | string;
+  /**
+   * The left part of the toggle field (unchecked).
+   */
+  left: ReactNode;
+  /**
+   * The right part of the toggle field (checked).
+   */
+  right: ReactNode;
 };
 
 export type ToggleProps = {
@@ -20,6 +27,10 @@ export type ToggleProps = {
    */
   label: string;
   /**
+   * The label size.
+   */
+  labelSize?: LabelProps['size'];
+  /**
    * The input name.
    */
   name: string;
@@ -38,13 +49,14 @@ export type ToggleProps = {
  *
  * Render a toggle with a label and two choices.
  */
-const Toggle: FC<ToggleProps> = ({
+const Toggle: VFC<ToggleProps> = ({
   choices,
   id,
   label,
+  labelSize,
   name,
-  value,
   setValue,
+  value,
 }) => {
   return (
     <>
@@ -56,12 +68,12 @@ const Toggle: FC<ToggleProps> = ({
         onChange={() => setValue(!value)}
         className={styles.checkbox}
       />
-      <label htmlFor={id} className={styles.label}>
+      <Label size={labelSize} htmlFor={id} className={styles.label}>
         <span className={styles.title}>{label}</span>
         {choices.left}
         <span className={styles.toggle}></span>
         {choices.right}
-      </label>
+      </Label>
     </>
   );
 };
diff --git a/src/components/atoms/headings/heading.stories.tsx b/src/components/atoms/headings/heading.stories.tsx
index cea3532..66a84dc 100644
--- a/src/components/atoms/headings/heading.stories.tsx
+++ b/src/components/atoms/headings/heading.stories.tsx
@@ -9,13 +9,13 @@ export default {
     withMargin: true,
   },
   argTypes: {
-    additionalClasses: {
+    className: {
       control: {
         type: 'text',
       },
-      description: 'Set additional classes.',
+      description: 'Set additional classnames.',
       table: {
-        category: 'Options',
+        category: 'Styles',
       },
       type: {
         name: 'string',
@@ -71,12 +71,12 @@ export default {
   },
 } as ComponentMeta<typeof HeadingComponent>;
 
-const Template: ComponentStory<typeof HeadingComponent> = (args) => {
-  const { level, ...props } = args;
-  return <HeadingComponent level={level || 1} {...props} />;
-};
+const Template: ComponentStory<typeof HeadingComponent> = (args) => (
+  <HeadingComponent {...args} />
+);
 
 export const Heading = Template.bind({});
 Heading.args = {
   children: 'Your title',
+  level: 1,
 };
diff --git a/src/components/atoms/headings/heading.tsx b/src/components/atoms/headings/heading.tsx
index 136571d..3048534 100644
--- a/src/components/atoms/headings/heading.tsx
+++ b/src/components/atoms/headings/heading.tsx
@@ -1,19 +1,21 @@
 import { FC } from 'react';
 import styles from './heading.module.scss';
 
+export type HeadingLevel = 1 | 2 | 3 | 4 | 5 | 6;
+
 export type HeadingProps = {
   /**
-   * Adds additional classes.
+   * Set additional classnames.
    */
-  additionalClasses?: string;
+  className?: string;
   /**
    * Use an heading element or only its styles. Default: false.
    */
   isFake?: boolean;
   /**
-   * HTML heading level: 'h1', 'h2', 'h3', 'h4', 'h5' or 'h6'.
+   * HTML heading level.
    */
-  level: 1 | 2 | 3 | 4 | 5 | 6;
+  level: HeadingLevel;
   /**
    * Adds margin. Default: true.
    */
@@ -27,7 +29,7 @@ export type HeadingProps = {
  */
 const Heading: FC<HeadingProps> = ({
   children,
-  additionalClasses,
+  className,
   isFake = false,
   level,
   withMargin = true,
@@ -38,7 +40,7 @@ const Heading: FC<HeadingProps> = ({
 
   return (
     <TitleTag
-      className={`${styles.heading} ${styles[levelClass]} ${styles[marginClass]} ${additionalClasses}`}
+      className={`${styles.heading} ${styles[levelClass]} ${styles[marginClass]} ${className}`}
     >
       {children}
     </TitleTag>
diff --git a/src/components/atoms/images/logo.stories.tsx b/src/components/atoms/images/logo.stories.tsx
index afb5317..fbc7501 100644
--- a/src/components/atoms/images/logo.stories.tsx
+++ b/src/components/atoms/images/logo.stories.tsx
@@ -4,6 +4,21 @@ import LogoComponent from './logo';
 export default {
   title: 'Atoms/Images',
   component: LogoComponent,
+  argTypes: {
+    title: {
+      control: {
+        type: 'text',
+      },
+      description: 'The SVG title.',
+      table: {
+        category: 'Accessibility',
+      },
+      type: {
+        name: 'string',
+        required: false,
+      },
+    },
+  },
 } as ComponentMeta<typeof LogoComponent>;
 
 const Template: ComponentStory<typeof LogoComponent> = (args) => (
diff --git a/src/components/atoms/images/logo.tsx b/src/components/atoms/images/logo.tsx
index 9ce2518..2e52110 100644
--- a/src/components/atoms/images/logo.tsx
+++ b/src/components/atoms/images/logo.tsx
@@ -1,4 +1,4 @@
-import { FC } from 'react';
+import { VFC } from 'react';
 import styles from './logo.module.scss';
 
 type LogoProps = {
@@ -13,7 +13,7 @@ type LogoProps = {
  *
  * Render a SVG logo.
  */
-const Logo: FC<LogoProps> = ({ title }) => {
+const Logo: VFC<LogoProps> = ({ title }) => {
   return (
     <svg
       viewBox="0 0 512 512"
diff --git a/src/components/atoms/links/link.stories.tsx b/src/components/atoms/links/link.stories.tsx
index e5a8b0a..569c874 100644
--- a/src/components/atoms/links/link.stories.tsx
+++ b/src/components/atoms/links/link.stories.tsx
@@ -15,6 +15,19 @@ export default {
         required: true,
       },
     },
+    className: {
+      control: {
+        type: 'text',
+      },
+      description: 'Set additional classnames.',
+      table: {
+        category: 'Styles',
+      },
+      type: {
+        name: 'string',
+        required: false,
+      },
+    },
     external: {
       control: {
         type: 'boolean',
diff --git a/src/components/atoms/links/link.tsx b/src/components/atoms/links/link.tsx
index a61158f..87f11fc 100644
--- a/src/components/atoms/links/link.tsx
+++ b/src/components/atoms/links/link.tsx
@@ -2,11 +2,11 @@ import NextLink from 'next/link';
 import { FC } from 'react';
 import styles from './link.module.scss';
 
-type LinkProps = {
+export type LinkProps = {
   /**
-   * Set additional classes to the link.
+   * Set additional classnames to the link.
    */
-  classes?: string;
+  className?: string;
   /**
    * True if it is an external link. Default: false.
    */
@@ -28,24 +28,22 @@ type LinkProps = {
  */
 const Link: FC<LinkProps> = ({
   children,
-  classes,
+  className = '',
   href,
   lang,
   external = false,
 }) => {
-  const additionalClasses = classes || '';
-
   return external ? (
     <a
       href={href}
       hrefLang={lang}
-      className={`${styles.link} ${styles['link--external']} ${additionalClasses}`}
+      className={`${styles.link} ${styles['link--external']} ${className}`}
     >
       {children}
     </a>
   ) : (
     <NextLink href={href}>
-      <a className={`${styles.link} ${additionalClasses}`}>{children}</a>
+      <a className={`${styles.link} ${className}`}>{children}</a>
     </NextLink>
   );
 };
diff --git a/src/components/atoms/links/nav-link.tsx b/src/components/atoms/links/nav-link.tsx
index 7c6fede..25c0e7d 100644
--- a/src/components/atoms/links/nav-link.tsx
+++ b/src/components/atoms/links/nav-link.tsx
@@ -1,5 +1,5 @@
 import Link from 'next/link';
-import { FC, ReactNode } from 'react';
+import { VFC, ReactNode } from 'react';
 import styles from './nav-link.module.scss';
 
 export type NavLinkProps = {
@@ -22,7 +22,7 @@ export type NavLinkProps = {
  *
  * Render a navigation link.
  */
-const NavLink: FC<NavLinkProps> = ({ href, label, logo }) => {
+const NavLink: VFC<NavLinkProps> = ({ href, label, logo }) => {
   return (
     <Link href={href}>
       <a className={styles.link}>
diff --git a/src/components/atoms/links/sharing-link.tsx b/src/components/atoms/links/sharing-link.tsx
index ca53ef9..3cd2dd1 100644
--- a/src/components/atoms/links/sharing-link.tsx
+++ b/src/components/atoms/links/sharing-link.tsx
@@ -1,4 +1,4 @@
-import { FC } from 'react';
+import { VFC } from 'react';
 import { useIntl } from 'react-intl';
 import styles from './sharing-link.module.scss';
 
@@ -26,7 +26,7 @@ export type SharingLinkProps = {
  *
  * Render a sharing link.
  */
-const SharingLink: FC<SharingLinkProps> = ({ medium, url }) => {
+const SharingLink: VFC<SharingLinkProps> = ({ medium, url }) => {
   const intl = useIntl();
   const text = intl.formatMessage(
     {
diff --git a/src/components/atoms/links/social-link.tsx b/src/components/atoms/links/social-link.tsx
index 489c8b4..8c7c790 100644
--- a/src/components/atoms/links/social-link.tsx
+++ b/src/components/atoms/links/social-link.tsx
@@ -2,14 +2,16 @@ import GithubIcon from '@assets/images/social-media/github.svg';
 import GitlabIcon from '@assets/images/social-media/gitlab.svg';
 import LinkedInIcon from '@assets/images/social-media/linkedin.svg';
 import TwitterIcon from '@assets/images/social-media/twitter.svg';
-import { FC } from 'react';
+import { VFC } from 'react';
 import styles from './social-link.module.scss';
 
-type SocialLinkProps = {
+export type SocialWebsite = 'Github' | 'Gitlab' | 'LinkedIn' | 'Twitter';
+
+export type SocialLinkProps = {
   /**
    * The social website name.
    */
-  name: 'Github' | 'Gitlab' | 'LinkedIn' | 'Twitter';
+  name: SocialWebsite;
   /**
    * The social profile url.
    */
@@ -21,7 +23,7 @@ type SocialLinkProps = {
  *
  * Render a social icon link.
  */
-const SocialLink: FC<SocialLinkProps> = ({ name, url }) => {
+const SocialLink: VFC<SocialLinkProps> = ({ name, url }) => {
   /**
    * Retrieve a social link icon by id.
    * @param {string} id - The social website id.
diff --git a/src/components/atoms/lists/description-list.stories.tsx b/src/components/atoms/lists/description-list.stories.tsx
index e9a60cf..c65241d 100644
--- a/src/components/atoms/lists/description-list.stories.tsx
+++ b/src/components/atoms/lists/description-list.stories.tsx
@@ -7,13 +7,13 @@ export default {
   title: 'Atoms/Lists',
   component: DescriptionListComponent,
   argTypes: {
-    classes: {
+    className: {
       control: {
         type: 'text',
       },
-      description: 'Set additional classes to the list wrapper.',
+      description: 'Set additional classnames to the list wrapper',
       table: {
-        category: 'Options',
+        category: 'Styles',
       },
       type: {
         name: 'string',
diff --git a/src/components/atoms/lists/description-list.tsx b/src/components/atoms/lists/description-list.tsx
index df2880f..a5ab1d5 100644
--- a/src/components/atoms/lists/description-list.tsx
+++ b/src/components/atoms/lists/description-list.tsx
@@ -1,4 +1,4 @@
-import { FC } from 'react';
+import { VFC } from 'react';
 import styles from './description-list.module.scss';
 
 export type DescriptionListItem = {
@@ -18,9 +18,9 @@ export type DescriptionListItem = {
 
 export type DescriptionListProps = {
   /**
-   * Set additional classes to the list wrapper.
+   * Set additional classnames to the list wrapper.
    */
-  classes?: string;
+  className?: string;
   /**
    * The list items.
    */
@@ -32,7 +32,10 @@ export type DescriptionListProps = {
  *
  * Render a description list.
  */
-const DescriptionList: FC<DescriptionListProps> = ({ classes = '', items }) => {
+const DescriptionList: VFC<DescriptionListProps> = ({
+  className = '',
+  items,
+}) => {
   /**
    * Retrieve the description list items wrapped in a div element.
    *
@@ -54,7 +57,7 @@ const DescriptionList: FC<DescriptionListProps> = ({ classes = '', items }) => {
     });
   };
 
-  return <dl className={`${styles.list} ${classes}`}>{getItems(items)}</dl>;
+  return <dl className={`${styles.list} ${className}`}>{getItems(items)}</dl>;
 };
 
 export default DescriptionList;
diff --git a/src/components/atoms/lists/list.stories.tsx b/src/components/atoms/lists/list.stories.tsx
index 6256e81..30079cb 100644
--- a/src/components/atoms/lists/list.stories.tsx
+++ b/src/components/atoms/lists/list.stories.tsx
@@ -8,13 +8,13 @@ export default {
     kind: 'unordered',
   },
   argTypes: {
-    classes: {
+    className: {
       control: {
         type: 'text',
       },
-      description: 'Add additional classes to the list element.',
+      description: 'Set additional classnames to the list wrapper',
       table: {
-        category: 'Options',
+        category: 'Styles',
       },
       type: {
         name: 'string',
diff --git a/src/components/atoms/lists/list.tsx b/src/components/atoms/lists/list.tsx
index 8ce8437..7197c34 100644
--- a/src/components/atoms/lists/list.tsx
+++ b/src/components/atoms/lists/list.tsx
@@ -1,4 +1,4 @@
-import { FC } from 'react';
+import { VFC } from 'react';
 import styles from './list.module.scss';
 
 export type ListItem = {
@@ -18,9 +18,9 @@ export type ListItem = {
 
 export type ListProps = {
   /**
-   * Add additional classes to the list element.
+   * Set additional classnames to the list wrapper
    */
-  classes?: string;
+  className?: string;
   /**
    * An array of list items.
    */
@@ -36,9 +36,8 @@ export type ListProps = {
  *
  * Render either an ordered or an unordered list.
  */
-const List: FC<ListProps> = ({ classes, items, kind = 'unordered' }) => {
+const List: VFC<ListProps> = ({ className, items, kind = 'unordered' }) => {
   const ListTag = kind === 'ordered' ? 'ol' : 'ul';
-  const additionalClasses = classes || '';
   const kindClass = `list--${kind}`;
 
   /**
@@ -52,7 +51,7 @@ const List: FC<ListProps> = ({ classes, items, kind = 'unordered' }) => {
         {value}
         {child && (
           <ListTag
-            className={`${styles.list} ${styles[kindClass]} ${additionalClasses}`}
+            className={`${styles.list} ${styles[kindClass]} ${className}`}
           >
             {getItems(child)}
           </ListTag>
@@ -62,9 +61,7 @@ const List: FC<ListProps> = ({ classes, items, kind = 'unordered' }) => {
   };
 
   return (
-    <ListTag
-      className={`${styles.list} ${styles[kindClass]} ${additionalClasses}`}
-    >
+    <ListTag className={`${styles.list} ${styles[kindClass]} ${className}`}>
       {getItems(items)}
     </ListTag>
   );
diff --git a/src/components/atoms/loaders/progress-bar.stories.tsx b/src/components/atoms/loaders/progress-bar.stories.tsx
index 837a696..4fde5a7 100644
--- a/src/components/atoms/loaders/progress-bar.stories.tsx
+++ b/src/components/atoms/loaders/progress-bar.stories.tsx
@@ -5,11 +5,14 @@ export default {
   title: 'Atoms/Loaders',
   component: ProgressBarComponent,
   argTypes: {
-    ariaLabel: {
+    'aria-label': {
       control: {
         type: 'string',
       },
       description: 'An accessible name.',
+      table: {
+        category: 'Accessibility',
+      },
       type: {
         name: 'string',
         required: false,
@@ -30,6 +33,9 @@ export default {
         type: 'text',
       },
       description: 'An additional information to display.',
+      table: {
+        category: 'Options',
+      },
       type: {
         name: 'string',
         required: false,
diff --git a/src/components/atoms/loaders/progress-bar.tsx b/src/components/atoms/loaders/progress-bar.tsx
index fa4e09d..1b1ff06 100644
--- a/src/components/atoms/loaders/progress-bar.tsx
+++ b/src/components/atoms/loaders/progress-bar.tsx
@@ -1,11 +1,11 @@
-import { FC } from 'react';
+import { VFC } from 'react';
 import styles from './progress-bar.module.scss';
 
 export type ProgressBarProps = {
   /**
    * Accessible progress bar name.
    */
-  ariaLabel?: string;
+  'aria-label'?: string;
   /**
    * Current value.
    */
@@ -29,12 +29,12 @@ export type ProgressBarProps = {
  *
  * Render a progress bar.
  */
-const ProgressBar: FC<ProgressBarProps> = ({
-  ariaLabel,
+const ProgressBar: VFC<ProgressBarProps> = ({
   current,
   info,
   min,
   max,
+  ...props
 }) => {
   return (
     <div className={styles.progress}>
@@ -46,7 +46,7 @@ const ProgressBar: FC<ProgressBarProps> = ({
         aria-valuemin={min}
         aria-valuemax={max}
         aria-valuenow={current}
-        aria-label={ariaLabel}
+        {...props}
       ></progress>
     </div>
   );
diff --git a/src/components/atoms/loaders/spinner.stories.tsx b/src/components/atoms/loaders/spinner.stories.tsx
index 86c316e..5006ce4 100644
--- a/src/components/atoms/loaders/spinner.stories.tsx
+++ b/src/components/atoms/loaders/spinner.stories.tsx
@@ -11,6 +11,9 @@ export default {
         type: 'text',
       },
       description: 'Loading message.',
+      table: {
+        category: 'Options',
+      },
       type: {
         name: 'string',
         required: false,
diff --git a/src/components/atoms/loaders/spinner.tsx b/src/components/atoms/loaders/spinner.tsx
index 57b0a43..bff0f25 100644
--- a/src/components/atoms/loaders/spinner.tsx
+++ b/src/components/atoms/loaders/spinner.tsx
@@ -1,8 +1,8 @@
-import { FC } from 'react';
+import { VFC } from 'react';
 import { useIntl } from 'react-intl';
 import styles from './spinner.module.scss';
 
-type SpinnerProps = {
+export type SpinnerProps = {
   /**
    * The loading message. Default: "Loading...".
    */
@@ -14,7 +14,7 @@ type SpinnerProps = {
  *
  * Render a loading message with animation.
  */
-const Spinner: FC<SpinnerProps> = ({ message }) => {
+const Spinner: VFC<SpinnerProps> = ({ message }) => {
   const intl = useIntl();
 
   return (
diff --git a/src/components/molecules/buttons/back-to-top.stories.tsx b/src/components/molecules/buttons/back-to-top.stories.tsx
index f1a36e5..fe58293 100644
--- a/src/components/molecules/buttons/back-to-top.stories.tsx
+++ b/src/components/molecules/buttons/back-to-top.stories.tsx
@@ -6,11 +6,14 @@ export default {
   title: 'Molecules/Buttons',
   component: BackToTopComponent,
   argTypes: {
-    additionalClasses: {
+    className: {
       control: {
         type: 'text',
       },
-      description: 'Add additional classes to the button wrapper.',
+      description: 'Set additional classnames to the button wrapper.',
+      table: {
+        category: 'Styles',
+      },
       type: {
         name: 'string',
         required: false,
diff --git a/src/components/molecules/buttons/back-to-top.tsx b/src/components/molecules/buttons/back-to-top.tsx
index f25d3e9..56c5247 100644
--- a/src/components/molecules/buttons/back-to-top.tsx
+++ b/src/components/molecules/buttons/back-to-top.tsx
@@ -1,14 +1,14 @@
 import ButtonLink from '@components/atoms/buttons/button-link';
 import Arrow from '@components/atoms/icons/arrow';
-import { FC } from 'react';
+import { VFC } from 'react';
 import { useIntl } from 'react-intl';
 import styles from './back-to-top.module.scss';
 
-type BackToTopProps = {
+export type BackToTopProps = {
   /**
-   * Add additional classes to the button wrapper.
+   * Set additional classnames to the button wrapper.
    */
-  additionalClasses?: string;
+  className?: string;
   /**
    * An element id (without hashtag) to use as anchor.
    */
@@ -20,7 +20,7 @@ type BackToTopProps = {
  *
  * Render a back to top link.
  */
-const BackToTop: FC<BackToTopProps> = ({ additionalClasses, target }) => {
+const BackToTop: VFC<BackToTopProps> = ({ className = '', target }) => {
   const intl = useIntl();
   const linkName = intl.formatMessage({
     defaultMessage: 'Back to top',
@@ -29,7 +29,7 @@ const BackToTop: FC<BackToTopProps> = ({ additionalClasses, target }) => {
   });
 
   return (
-    <div className={`${styles.wrapper} ${additionalClasses}`}>
+    <div className={`${styles.wrapper} ${className}`}>
       <ButtonLink shape="square" target={`#${target}`} aria-label={linkName}>
         <Arrow direction="top" />
       </ButtonLink>
diff --git a/src/components/molecules/buttons/help-button.stories.tsx b/src/components/molecules/buttons/help-button.stories.tsx
index 7ed953e..cfc1b0b 100644
--- a/src/components/molecules/buttons/help-button.stories.tsx
+++ b/src/components/molecules/buttons/help-button.stories.tsx
@@ -6,11 +6,11 @@ export default {
   title: 'Molecules/Buttons',
   component: HelpButtonComponent,
   argTypes: {
-    classes: {
+    className: {
       control: {
         type: 'text',
       },
-      description: 'Set additional classes to the button.',
+      description: 'Set additional classnames to the button wrapper.',
       table: {
         category: 'Options',
       },
diff --git a/src/components/molecules/buttons/help-button.tsx b/src/components/molecules/buttons/help-button.tsx
index d933829..aeb84ec 100644
--- a/src/components/molecules/buttons/help-button.tsx
+++ b/src/components/molecules/buttons/help-button.tsx
@@ -1,13 +1,13 @@
 import Button, { ButtonProps } from '@components/atoms/buttons/button';
-import { FC } from 'react';
+import { VFC } from 'react';
 import { useIntl } from 'react-intl';
 import styles from './help-button.module.scss';
 
 export type HelpButtonProps = Pick<ButtonProps, 'onClick'> & {
   /**
-   * Set additional classes to the button.
+   * Set additional classnames to the button wrapper.
    */
-  classes?: string;
+  className?: string;
 };
 
 /**
@@ -15,7 +15,7 @@ export type HelpButtonProps = Pick<ButtonProps, 'onClick'> & {
  *
  * Render a button with an interrogation mark icon.
  */
-const HelpButton: FC<HelpButtonProps> = ({ classes = '', onClick }) => {
+const HelpButton: VFC<HelpButtonProps> = ({ className = '', onClick }) => {
   const intl = useIntl();
   const text = intl.formatMessage({
     defaultMessage: 'Help',
@@ -26,7 +26,7 @@ const HelpButton: FC<HelpButtonProps> = ({ classes = '', onClick }) => {
   return (
     <Button
       shape="circle"
-      additionalClasses={`${styles.btn} ${classes}`}
+      className={`${styles.btn} ${className}`}
       onClick={onClick}
     >
       <span className="screen-reader-text">{text}</span>
diff --git a/src/components/molecules/images/responsive-image.tsx b/src/components/molecules/images/responsive-image.tsx
index db2f5ab..9f96f18 100644
--- a/src/components/molecules/images/responsive-image.tsx
+++ b/src/components/molecules/images/responsive-image.tsx
@@ -1,6 +1,6 @@
 import Link from '@components/atoms/links/link';
 import Image, { ImageProps } from 'next/image';
-import { FC } from 'react';
+import { VFC } from 'react';
 import styles from './responsive-image.module.scss';
 
 type ResponsiveImageProps = Omit<ImageProps, 'alt' | 'width' | 'height'> & {
@@ -31,7 +31,7 @@ type ResponsiveImageProps = Omit<ImageProps, 'alt' | 'width' | 'height'> & {
  *
  * Render a responsive image wrapped in a figure element.
  */
-const ResponsiveImage: FC<ResponsiveImageProps> = ({
+const ResponsiveImage: VFC<ResponsiveImageProps> = ({
   alt,
   caption,
   layout,
@@ -42,7 +42,7 @@ const ResponsiveImage: FC<ResponsiveImageProps> = ({
   return (
     <figure className={styles.wrapper}>
       {target ? (
-        <Link href={target} classes={styles.link}>
+        <Link href={target} className={styles.link}>
           <Image alt={alt} layout={layout || 'intrinsic'} {...props} />
           {caption && (
             <figcaption className={styles.caption}>{caption}</figcaption>
diff --git a/src/components/molecules/layout/branding.tsx b/src/components/molecules/layout/branding.tsx
index efb2e34..9f564bf 100644
--- a/src/components/molecules/layout/branding.tsx
+++ b/src/components/molecules/layout/branding.tsx
@@ -1,6 +1,6 @@
 import Heading from '@components/atoms/headings/heading';
 import Link from 'next/link';
-import { FC } from 'react';
+import { VFC } from 'react';
 import { useIntl } from 'react-intl';
 import styles from './branding.module.scss';
 import FlippingLogo from './flipping-logo';
@@ -33,7 +33,7 @@ type BrandingProps = {
  *
  * Render the branding logo, title and optional baseline.
  */
-const Branding: FC<BrandingProps> = ({
+const Branding: VFC<BrandingProps> = ({
   baseline,
   isHome = false,
   photo,
@@ -61,7 +61,7 @@ const Branding: FC<BrandingProps> = ({
   return (
     <div className={styles.wrapper}>
       <FlippingLogo
-        additionalClasses={styles.logo}
+        className={styles.logo}
         altText={altText}
         logoTitle={logoTitle}
         photo={photo}
@@ -70,7 +70,7 @@ const Branding: FC<BrandingProps> = ({
         isFake={!isHome}
         level={1}
         withMargin={false}
-        additionalClasses={styles.title}
+        className={styles.title}
       >
         {withLink ? (
           <Link href="/">
@@ -85,7 +85,7 @@ const Branding: FC<BrandingProps> = ({
           isFake={true}
           level={4}
           withMargin={false}
-          additionalClasses={styles.baseline}
+          className={styles.baseline}
         >
           {baseline}
         </Heading>
diff --git a/src/components/molecules/layout/flipping-logo.stories.tsx b/src/components/molecules/layout/flipping-logo.stories.tsx
index 1508269..1ac8de8 100644
--- a/src/components/molecules/layout/flipping-logo.stories.tsx
+++ b/src/components/molecules/layout/flipping-logo.stories.tsx
@@ -5,11 +5,21 @@ export default {
   title: 'Molecules/Layout',
   component: FlippingLogoComponent,
   argTypes: {
-    additionalClasses: {
+    altText: {
+      control: {
+        type: 'text',
+      },
+      description: 'Photo alternative text.',
+      type: {
+        name: 'string',
+        required: true,
+      },
+    },
+    className: {
       control: {
         type: 'text',
       },
-      description: 'Adds additional classes to the logo wrapper.',
+      description: 'Set additional classnames to the logo wrapper.',
       table: {
         category: 'Options',
       },
@@ -18,14 +28,17 @@ export default {
         required: false,
       },
     },
-    altText: {
+    logoTitle: {
       control: {
         type: 'text',
       },
-      description: 'Photo alternative text.',
+      description: 'An accessible name for the logo.',
+      table: {
+        category: 'Accessibility',
+      },
       type: {
         name: 'string',
-        required: true,
+        required: false,
       },
     },
     photo: {
diff --git a/src/components/molecules/layout/flipping-logo.tsx b/src/components/molecules/layout/flipping-logo.tsx
index 7bb7afc..6f7645f 100644
--- a/src/components/molecules/layout/flipping-logo.tsx
+++ b/src/components/molecules/layout/flipping-logo.tsx
@@ -1,13 +1,13 @@
 import Logo from '@components/atoms/images/logo';
 import Image from 'next/image';
-import { FC } from 'react';
+import { VFC } from 'react';
 import styles from './flipping-logo.module.scss';
 
 type FlippingLogoProps = {
   /**
-   * Adds additional classes to the logo wrapper.
+   * Set additional classnames to the logo wrapper.
    */
-  additionalClasses?: string;
+  className?: string;
   /**
    * Photo alternative text.
    */
@@ -27,14 +27,14 @@ type FlippingLogoProps = {
  *
  * Render a logo and a photo with a flipping effect.
  */
-const FlippingLogo: FC<FlippingLogoProps> = ({
-  additionalClasses,
+const FlippingLogo: VFC<FlippingLogoProps> = ({
+  className = '',
   altText,
   logoTitle,
   photo,
 }) => {
   return (
-    <div className={`${styles.logo} ${additionalClasses}`}>
+    <div className={`${styles.logo} ${className}`}>
       <div className={styles.logo__front}>
         <Image src={photo} alt={altText} layout="fill" objectFit="cover" />
       </div>
diff --git a/src/components/molecules/modals/modal.stories.tsx b/src/components/molecules/modals/modal.stories.tsx
index b68a24b..bd7d9f4 100644
--- a/src/components/molecules/modals/modal.stories.tsx
+++ b/src/components/molecules/modals/modal.stories.tsx
@@ -15,6 +15,19 @@ export default {
         required: true,
       },
     },
+    className: {
+      control: {
+        type: 'text',
+      },
+      description: 'Set additional classnames to the modal.',
+      table: {
+        category: 'Styles',
+      },
+      type: {
+        name: 'string',
+        required: false,
+      },
+    },
     icon: {
       control: {
         type: 'select',
diff --git a/src/components/molecules/modals/modal.tsx b/src/components/molecules/modals/modal.tsx
index 4dc3b0a..ce12e7a 100644
--- a/src/components/molecules/modals/modal.tsx
+++ b/src/components/molecules/modals/modal.tsx
@@ -1,17 +1,29 @@
 import Heading from '@components/atoms/headings/heading';
+import { CogProps } from '@components/atoms/icons/cog';
+import { MagnifyingGlassProps } from '@components/atoms/icons/magnifying-glass';
 import dynamic from 'next/dynamic';
-import { FC, ReactNode } from 'react';
+import { FC } from 'react';
 import styles from './modal.module.scss';
 
 export type Icons = 'cogs' | 'search';
 
 export type ModalProps = {
+  /**
+   * Set additional classnames.
+   */
+  className?: string;
+  /**
+   * A icon to illustrate the modal.
+   */
   icon?: Icons;
+  /**
+   * The modal title.
+   */
   title?: string;
 };
 
-const CogIcon = dynamic<ReactNode>(() => import('@components/atoms/icons/cog'));
-const SearchIcon = dynamic<ReactNode>(
+const CogIcon = dynamic<CogProps>(() => import('@components/atoms/icons/cog'));
+const SearchIcon = dynamic<MagnifyingGlassProps>(
   () => import('@components/atoms/icons/magnifying-glass')
 );
 
@@ -20,7 +32,7 @@ const SearchIcon = dynamic<ReactNode>(
  *
  * Render a modal component with an optional title and icon.
  */
-const Modal: FC<ModalProps> = ({ children, icon, title }) => {
+const Modal: FC<ModalProps> = ({ children, className = '', icon, title }) => {
   const getIcon = (id: Icons) => {
     switch (id) {
       case 'cogs':
@@ -33,7 +45,7 @@ const Modal: FC<ModalProps> = ({ children, icon, title }) => {
   };
 
   return (
-    <div className={styles.wrapper}>
+    <div className={`${styles.wrapper} ${className}`}>
       {title && (
         <Heading isFake={true} level={3}>
           {icon && <span className={styles.icon}>{getIcon(icon)}</span>}
diff --git a/src/components/molecules/modals/tooltip.stories.tsx b/src/components/molecules/modals/tooltip.stories.tsx
index a57cf34..63fc71d 100644
--- a/src/components/molecules/modals/tooltip.stories.tsx
+++ b/src/components/molecules/modals/tooltip.stories.tsx
@@ -5,6 +5,19 @@ export default {
   title: 'Molecules/Modals',
   component: TooltipComponent,
   argTypes: {
+    className: {
+      control: {
+        type: 'text',
+      },
+      description: 'Set additional classnames to the tooltip.',
+      table: {
+        category: 'Styles',
+      },
+      type: {
+        name: 'string',
+        required: false,
+      },
+    },
     content: {
       control: {
         type: 'text',
@@ -15,6 +28,16 @@ export default {
         required: true,
       },
     },
+    icon: {
+      control: {
+        type: 'text',
+      },
+      description: 'The tooltip icon.',
+      type: {
+        name: 'string',
+        required: true,
+      },
+    },
     title: {
       control: {
         type: 'text',
diff --git a/src/components/molecules/modals/tooltip.tsx b/src/components/molecules/modals/tooltip.tsx
index ceb0b14..73f36e7 100644
--- a/src/components/molecules/modals/tooltip.tsx
+++ b/src/components/molecules/modals/tooltip.tsx
@@ -1,12 +1,12 @@
 import List, { type ListItem } from '@components/atoms/lists/list';
-import { FC, ReactNode } from 'react';
+import { ReactNode, VFC } from 'react';
 import styles from './tooltip.module.scss';
 
 export type TooltipProps = {
   /**
-   * Set additional classes to the tooltip wrapper.
+   * Set additional classnames to the tooltip wrapper.
    */
-  classes?: string;
+  className?: string;
   /**
    * The tooltip body.
    */
@@ -26,7 +26,12 @@ export type TooltipProps = {
  *
  * Render a tooltip modal.
  */
-const Tooltip: FC<TooltipProps> = ({ classes = '', content, icon, title }) => {
+const Tooltip: VFC<TooltipProps> = ({
+  className = '',
+  content,
+  icon,
+  title,
+}) => {
   /**
    * Format an array of strings to an array of object with id and value.
    *
@@ -40,7 +45,7 @@ const Tooltip: FC<TooltipProps> = ({ classes = '', content, icon, title }) => {
   };
 
   return (
-    <div className={`${styles.wrapper} ${classes}`}>
+    <div className={`${styles.wrapper} ${className}`}>
       <div className={styles.title}>
         <span className={styles.icon}>{icon}</span>
         {title}