Change CSS variable names + create a themer (#109)

Try it out at https://csclub.uwaterloo.ca/~a3thakra/website-demo/themer/

- Themes persist across website reloads
- Individual color reset buttons
- Reset all colors button

Reviewed-on: #109
Reviewed-by: n3parikh <n3parikh@localhost>
Reviewed-by: b38peng <b38peng@uwaterloo.ca>
Co-authored-by: Aditya Thakral <a3thakra@csclub.uwaterloo.ca>
Co-committed-by: Aditya Thakral <a3thakra@csclub.uwaterloo.ca>

components/Bubble.module.css

@@ -3,5 +3,5 @@
 }
 
 .bubble:nth-child(odd) {
-  background-color: var(--blue-1-20);
+  background-color: var(--primary-accent-light);
 }

components/Button.module.css

@@ -2,8 +2,8 @@
 .link {
   font-family: "Poppins", "sans-serif";
   border-radius: calc(20rem / 16);
-  background-color: var(--blue-2);
-  color: white;
+  background-color: var(--primary-accent);
+  color: var(--primary-background);
   border: none;
   outline: none;
   transition-duration: 0.3s;
@@ -13,7 +13,7 @@
 
 .button:hover,
 .link:hover {
-  background-color: var(--teal-2);
+  background-color: var(--secondary-accent);
   cursor: pointer;
 }
 

components/ConnectWithUs.module.css

@@ -1,5 +1,5 @@
 .header {
-  color: var(--blue-2);
+  color: var(--primary-accent);
   font-weight: 600;
   font-size: calc(36rem / 16);
 }

components/EmailSignup.module.css

@@ -3,7 +3,7 @@
 }
 
 .header {
-  color: var(--blue-2);
+  color: var(--primary-accent);
   font-weight: 600;
   font-size: calc(36rem / 16);
 }

components/EventCard.module.css

@@ -41,7 +41,7 @@
 }
 
 .content > h2 {
-  color: var(--purple-2);
+  color: var(--primary-heading);
   font-size: 1rem;
   margin-bottom: calc(14rem / 16);
 }

components/EventDescriptionCard.module.css

@@ -4,7 +4,7 @@
   max-width: calc(540rem / 16);
   padding: calc(24rem / 16);
   border-radius: calc(20rem / 16);
-  background-color: white;
+  background-color: var(--primary-background);
 }
 
 .poster {
@@ -35,7 +35,7 @@
 
 .setting {
   margin: 0;
-  color: var(--blue-2);
+  color: var(--primary-accent);
   font-size: calc(14rem / 16);
   font-weight: 600;
 }
@@ -67,7 +67,7 @@
   .poster {
     width: calc(95rem / 16);
     height: calc(95rem / 16);
-    border: 1px solid var(--purple-2);
+    border: 1px solid var(--primary-heading);
     box-sizing: border-box;
     margin-right: calc(14rem / 16);
   }

components/Footer.module.css

@@ -1,6 +1,6 @@
 .footer {
   box-sizing: border-box;
-  background: var(--purple-2);
+  background: var(--primary-heading);
   height: calc(66rem / 16);
   padding: calc(14rem / 16) 0;
   width: 100%;
@@ -18,7 +18,7 @@
 }
 
 .text {
-  color: var(--white);
+  color: var(--primary-background);
   font-style: normal;
   text-align: center;
 }

components/Input.module.css

@@ -8,20 +8,20 @@
   border: 0;
   border-radius: calc(20rem / 16);
 
-  background-color: var(--grey-1-24);
+  background-color: var(--input-background);
   font-size: calc(18rem / 16);
   line-height: calc(30rem / 16);
-  color: var(--grey-3);
+  color: var(--input-text);
 }
 
 .input::placeholder {
-  color: var(--grey-2);
+  color: var(--input-placeholder-text);
   font-weight: 700;
 }
 
 .input:is(:active, :hover, :focus) {
   box-sizing: border-box;
-  border: calc(3rem / 16) solid var(--blue-1);
+  border: calc(3rem / 16) solid var(--primary-accent-soft);
   border-radius: calc(20rem / 16);
   outline: none;
   padding: calc(7rem / 16) calc(28rem / 16);

components/Link.module.css

@@ -1,10 +1,10 @@
 .link {
-  color: var(--blue-2);
+  color: var(--primary-accent);
   transition-duration: 0.3s;
   text-decoration: none;
   white-space: normal;
 }
 
 .link:hover {
-  color: var(--teal-2);
+  color: var(--secondary-accent);
 }

components/MiniEventCard.module.css

@@ -5,7 +5,7 @@
 }
 
 .card:nth-child(odd) {
-  background-color: var(--teal-2-20);
+  background-color: var(--secondary-accent-light);
 }
 
 .name {
@@ -19,7 +19,7 @@
 }
 
 .info {
-  color: var(--purple-2);
+  color: var(--primary-heading);
   margin-bottom: calc(12rem / 16);
 }
 
@@ -29,7 +29,7 @@
   right: 0;
   cursor: pointer;
   margin: calc(20rem / 16);
-  color: var(--blue-2);
+  color: var(--primary-accent);
   font-size: calc(14rem / 16);
 }
 
@@ -46,5 +46,5 @@
 }
 
 .dropDownIcon {
-  fill: var(--blue-2);
+  fill: var(--primary-accent);
 }

components/Navbar.module.css

@@ -4,7 +4,7 @@
   align-items: center;
   z-index: 10;
 
-  background-color: var(--white);
+  background-color: var(--primary-background);
 }
 
 .navContent {
@@ -63,16 +63,16 @@
 }
 
 .navMenu a {
-  color: var(--purple-2);
+  color: var(--primary-heading);
   text-decoration: none;
 }
 
 .navMenu a.currentPage {
-  color: var(--blue-2);
+  color: var(--primary-accent);
 }
 
 .navMenu > li > a:hover {
-  color: var(--blue-2);
+  color: var(--primary-accent);
   font-weight: 600;
 }
 
@@ -116,8 +116,8 @@
   padding: 0;
 
   border-radius: calc(8rem / 16);
-  background-color: var(--white);
-  box-shadow: 0 calc(8rem / 16) 1rem var(--blue-1-20);
+  background-color: var(--primary-background);
+  box-shadow: 0 calc(8rem / 16) 1rem var(--primary-accent-light);
 
   font-size: calc(14rem / 16);
 }
@@ -134,7 +134,7 @@
 
 .dropdown li:hover a,
 .dropdown li a:focus {
-  background-color: var(--blue-1-20);
+  background-color: var(--primary-accent-light);
 }
 
 .dropdown li:first-child a {
@@ -224,7 +224,7 @@
     left: 0;
     z-index: 20;
 
-    background-color: var(--navbar-gray);
+    background-color: var(--navbar-page-overlay);
     opacity: 0;
 
     transition: 0.5s;
@@ -244,7 +244,7 @@
     padding: calc(calc(64rem / 16) - 1rem);
     padding-left: calc(calc(78rem / 16) - 1rem);
 
-    background-color: var(--off-white);
+    background-color: var(--secondary-background);
 
     transform: translateX(100vw);
     transition: 0.5s;

components/NewsCard.module.css

@@ -1,7 +1,7 @@
 .card {
   padding: calc(30rem / 16) calc(40rem / 16);
   max-width: calc(524rem / 16);
-  background-color: var(--white);
+  background-color: var(--primary-background);
   border-radius: calc(20rem / 16);
 }
 
@@ -11,7 +11,7 @@
 }
 
 .author {
-  color: var(--purple-1);
+  color: var(--secondary-heading);
   font-style: normal;
 }
 

components/OrganizedContent.module.css

@@ -6,7 +6,7 @@
   margin: 1rem 0;
   font-size: calc(24rem / 16);
   font-weight: 600;
-  color: var(--blue-2);
+  color: var(--primary-accent);
 }
 
 .content {
@@ -17,7 +17,7 @@
 
 .nav {
   margin: calc(8rem / 16) calc(32rem / 16) 0 0;
-  color: var(--purple-2);
+  color: var(--primary-heading);
   font-weight: 500;
 }
 
@@ -26,7 +26,7 @@
   overflow: hidden;
   white-space: nowrap;
   font-size: calc(14rem / 16);
-  border-bottom: calc(1rem / 16) solid var(--blue-2-25);
+  border-bottom: calc(1rem / 16) solid var(--primary-accent-light);
   align-items: center;
   height: calc(40rem / 16);
   width: calc(284rem / 16);
@@ -41,8 +41,8 @@
 }
 
 .selected {
-  background-color: var(--blue-1-05);
-  color: var(--blue-2);
+  background-color: var(--primary-accent-dim);
+  color: var(--primary-accent);
   font-weight: 700;
 }
 
@@ -56,7 +56,7 @@
 
 .selected .marker {
   display: inline;
-  background-color: var(--blue-2);
+  background-color: var(--primary-accent);
   height: calc(24rem / 16);
   width: calc(4rem / 16);
   margin-right: 1rem;
@@ -73,7 +73,7 @@
   flex: 1;
   display: flex;
   cursor: pointer;
-  color: var(--purple-2);
+  color: var(--primary-heading);
   font-size: calc(12rem / 16);
 }
 
@@ -88,15 +88,15 @@
 }
 
 .arrowHeading {
-  color: var(--blue-2);
+  color: var(--primary-accent);
   font-size: calc(14rem / 16);
   font-weight: 700;
-  border-bottom: calc(2rem / 16) solid var(--blue-2);
+  border-bottom: calc(2rem / 16) solid var(--primary-accent);
   padding-bottom: calc(4rem / 16);
 }
 
 .arrow {
-  fill: var(--blue-2);
+  fill: var(--primary-accent);
   margin-top: calc(27rem / 16);
 }
 

components/SocialLinks.module.css

@@ -18,9 +18,9 @@
 }
 
 .blue {
-  fill: var(--blue-1);
+  fill: var(--primary-accent-soft);
 }
 
 .white {
-  fill: var(--white);
+  fill: var(--primary-background);
 }

components/TeamMember.module.css

@@ -18,10 +18,10 @@
 
 .name {
   font-weight: 700;
-  color: var(--blue-2);
+  color: var(--primary-accent);
 }
 
 .role {
   font-weight: 600;
-  color: var(--purple-2);
+  color: var(--primary-heading);
 }

components/TeamMemberCard.module.css

@@ -29,7 +29,7 @@
   grid-area: name;
   margin: 0;
 
-  color: var(--blue-2);
+  color: var(--primary-accent);
   font-size: calc(36rem / 16);
   font-weight: 600;
 }

components/Theme.tsx

@@ -0,0 +1,178 @@
+import React, {
+  createContext,
+  ReactElement,
+  useContext,
+  useEffect,
+  useState,
+} from "react";
+
+type BuiltInThemes = "light" | "dark";
+
+export interface Theme {
+  name: BuiltInThemes | "custom";
+  palette: Palette;
+}
+
+export type SetThemeInput = BuiltInThemes | Partial<Palette>;
+
+export const PALETTE_NAMES = [
+  "--primary-background",
+  "--secondary-background",
+
+  "--primary-accent",
+  "--primary-accent-soft",
+  "--primary-accent-light",
+  "--primary-accent-dim",
+
+  "--secondary-accent",
+  "--secondary-accent-light",
+
+  "--primary-heading",
+  "--secondary-heading",
+
+  "--text",
+
+  "--form-invalid",
+
+  "--input-background",
+  "--input-placeholder-text",
+  "--input-text",
+
+  "--navbar-page-overlay",
+] as const;
+
+export const emptyPalette = PALETTE_NAMES.reduce(
+  (partial, varName) => ({
+    ...partial,
+    [varName]: "#c4e0f8",
+  }),
+  {} as Palette
+);
+
+const ThemeContext =
+  createContext<
+    | {
+        theme: Theme;
+        setTheme(input: SetThemeInput): void;
+        save(): void;
+        clearSaved(): void;
+      }
+    | undefined
+  >(undefined);
+
+export interface Props {
+  children?: ReactElement;
+}
+
+export function ThemeProvider(props: Props) {
+  const update = useForcedUpdate();
+  const [themeName, setThemeName] =
+    useState<Theme["name"] | undefined>(undefined);
+
+  const setTheme = (input: SetThemeInput) => {
+    if (typeof input === "string") {
+      PALETTE_NAMES.forEach((name) =>
+        document.body.style.setProperty(name, "")
+      );
+
+      if (input === "light") {
+        document.body.classList.remove("dark");
+      } else if (input === "dark") {
+        document.body.classList.add("dark");
+      }
+
+      setThemeName(input);
+    } else {
+      const properties = Object.keys(input) as PaletteNames[];
+
+      properties.forEach((property) =>
+        document.body.style.setProperty(
+          property,
+          input[property]?.trim() ?? null
+        )
+      );
+
+      setThemeName("custom");
+    }
+
+    update();
+  };
+
+  useEffect(() => {
+    const customPalette = getSavedPalette();
+
+    if (customPalette == null) {
+      setThemeName("light");
+    } else {
+      setTheme(customPalette);
+      setThemeName("custom");
+    }
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, []);
+
+  return (
+    <ThemeContext.Provider
+      value={
+        themeName == null
+          ? undefined
+          : {
+              theme: {
+                name: themeName,
+                get palette() {
+                  return getCurrentPalette();
+                },
+              },
+              setTheme,
+              save: () => savePalette(getCurrentPalette()),
+              clearSaved: clearSavedPalette,
+            }
+      }
+    >
+      {props.children}
+    </ThemeContext.Provider>
+  );
+}
+
+export function useThemeContext() {
+  return useContext(ThemeContext);
+}
+
+export type PaletteNames = typeof PALETTE_NAMES[number];
+
+export type Palette = {
+  [key in PaletteNames]: string;
+};
+
+function getCurrentPalette() {
+  const styles = getComputedStyle(document.body);
+
+  return PALETTE_NAMES.reduce(
+    (partial, varName) => ({
+      ...partial,
+      [varName]: styles.getPropertyValue(varName).trim(),
+    }),
+    {} as Palette
+  );
+}
+
+function useForcedUpdate() {
+  const [fakeState, setFakeState] = useState(true);
+
+  return () => setFakeState(!fakeState);
+}
+
+const STORAGE_KEY = "csc-theme-palette";
+
+function getSavedPalette() {
+  const raw = localStorage.getItem(STORAGE_KEY);
+
+  return raw == null ? undefined : (JSON.parse(raw) as Palette);
+}
+
+function savePalette(palette: Palette) {
+  localStorage.setItem(STORAGE_KEY, JSON.stringify(palette));
+}
+
+function clearSavedPalette() {
+  localStorage.removeItem(STORAGE_KEY);
+}

components/playground.module.css

@@ -1,13 +1,13 @@
 .newsDemo {
   padding: calc(50rem / 16);
-  background-color: var(--off-white);
+  background-color: var(--secondary-background);
   display: inline-block;
 }
 
 .newsTitle {
   font-style: normal;
   font-weight: bold;
-  color: var(--purple-2);
+  color: var(--primary-heading);
   font-size: calc(24rem / 16);
   line-height: calc(36 / 24);
   margin-bottom: calc(14rem / 16);
@@ -19,20 +19,20 @@
   font-size: calc(14rem / 16);
   line-height: calc(21 / 14);
   white-space: pre-line;
-  color: var(--purple-2);
+  color: var(--primary-heading);
   vertical-align: baseline;
 }
 
 .news > hr {
   border: none;
   height: calc(1rem / 16);
-  background-color: var(--purple-2);
+  background-color: var(--primary-heading);
   margin: 0 0 calc(13rem / 16) 0;
 }
 
 .eventDescriptionCardDemo {
   padding: calc(50rem / 16) 0;
-  background-color: var(--off-white);
+  background-color: var(--secondary-background);
   display: inline-block;
 }
 
@@ -54,7 +54,7 @@
 
 .committee {
   margin: 0;
-  color: var(--purple-2);
+  color: var(--primary-heading);
   font-weight: 600;
   font-size: calc(24rem / 16);
   line-height: calc(36 / 24);
@@ -63,7 +63,7 @@
 .teamMemberDemo > hr {
   border: none;
   height: calc(1rem / 16);
-  background-color: var(--blue-2);
+  background-color: var(--primary-accent);
   width: 100%;
   margin-top: calc(24rem / 16);
   margin-bottom: calc(46rem / 16);
@@ -78,24 +78,24 @@
 
 .linkDemo {
   padding: calc(50rem / 16);
-  background-color: var(--off-white);
+  background-color: var(--secondary-background);
 }
 
 .linkTitle {
   font-weight: bold;
-  color: var(--purple-2);
+  color: var(--primary-heading);
   font-size: calc(24rem / 16);
 }
 
 .miniTechTalkDemo > *:nth-child(odd) {
-  background: var(--background-teal-2);
+  background: var(--secondary-accent-light);
 }
 
 @media only screen and (max-width: calc(768rem / 16)) {
   .newsDemo,
   .eventDescriptionCardDemo {
     padding: calc(20rem / 16);
-    background-color: var(--off-white);
+    background-color: var(--secondary-background);
   }
 
   .eventDescriptionCardDemo > * {

components/theme.tsx

@@ -1,36 +0,0 @@
-import React, { createContext, ReactElement, useEffect, useState } from "react";
-
-type Theme = "light" | "dark";
-
-const ThemeContext = createContext<{
-  theme: Theme;
-  setTheme(newTheme: Theme): void;
-}>({
-  theme: "light",
-  setTheme: () => {
-    throw new Error("Use ThemeProvider instead.");
-  },
-});
-
-interface Props {
-  theme: Theme;
-  children?: ReactElement;
-}
-
-export function ThemeProvider({ children, theme }: Props) {
-  const [currentTheme, setTheme] = useState(theme);
-
-  useEffect(() => {
-    if (currentTheme === "light") {
-      document.body.classList.remove("dark");
-    } else if (currentTheme === "dark") {
-      document.body.classList.add("dark");
-    }
-  }, [currentTheme]);
-
-  return (
-    <ThemeContext.Provider value={{ theme: currentTheme, setTheme }}>
-      {children}
-    </ThemeContext.Provider>
-  );
-}

pages/_app.css

@@ -1,35 +1,31 @@
 body {
   /* Default is light theme */
-  --white: #ffffff;
-  --off-white: #fdf8f5;
-  --teal-1: #76ffdc;
-  --teal-2: #4ed4b2;
-  --teal-2-20: #4ed4b234;
-  --blue-1: #5caff9;
-  --blue-1-05: #5caff90d;
-  --blue-1-20: #5caff934;
-  --blue-2: #1482e3;
-  --blue-2-25: #1482e340;
-  --purple-1: #525284;
-  --purple-2: #2a2a62;
-  --black: #000000;
-  --grey-1: #c4c4c4;
-  --grey-1-24: #c4c4c440;
-  --grey-2: #bbbbbb;
-  --grey-3: #6b6b6b;
-  --red: #9f616a;
-  --gradient-blue-green: linear-gradient(
-    99.94deg,
-    #1481e3 -17.95%,
-    #4ed4b2 172.82%
-  );
-  --background-teal-2: rgb(78, 212, 178, 0.2);
-  /* used in mobile navbar background */
-  --navbar-gray: #787878b2;
-  /* used in home page */
-  --home-title-purple: #27153e;
+  --primary-background: #ffffff;
+  --secondary-background: #fdf8f5;
 
-  color: var(--black);
+  --primary-accent: #1482e3;
+  --primary-accent-soft: #5caff9;
+  --primary-accent-light: #c4e0f8;
+  --primary-accent-dim: #f7fbff;
+
+  --secondary-accent: #4ed4b2;
+  --secondary-accent-light: #dcf6f0;
+
+  --primary-heading: #2a2a62;
+  --secondary-heading: #525284;
+
+  --text: #000000;
+
+  --form-invalid: #9f616a;
+
+  --input-background: #f0f0f0;
+  --input-placeholder-text: #bbbbbb;
+  --input-text: #6b6b6b;
+
+  --navbar-page-overlay: #787878b2;
+
+  background-color: var(--primary-background);
+  color: var(--text);
   font-family: "Poppins", "sans-serif";
   font-size: 1rem;
   font-weight: 400;
@@ -42,25 +38,8 @@ input {
   font-family: "Poppins", "sans-serif";
 }
 
-/* FIXME: Dark theme is the same as light theme right now */
 .dark {
-  --white: #ffffff;
-  --off-white: #fdf8f5;
-  --teal-1: #76ffdc;
-  --teal-2: #4ed4b2;
-  --blue-1: #5caff9;
-  --blue-1-05: #5caff90d;
-  --blue-1-20: #5caff934;
-  --blue-2: #1482e3;
-  --purple-1: #525284;
-  --purple-2: #2a2a62;
-  --gradient-blue-green: linear-gradient(
-    99.94deg,
-    #1481e3 -17.95%,
-    #4ed4b2 172.82%
-  );
-  /* used in mobile navbar background */
-  --navbar-gray: #787878b2;
+  /* FIXME: Implement dark theme */
 }
 
 h1,
@@ -71,7 +50,7 @@ h5,
 h6 {
   font-style: normal;
   line-height: 1.5;
-  color: var(--purple-2);
+  color: var(--primary-heading);
 }
 
 h1,

pages/_app.tsx

@@ -2,7 +2,7 @@ import React, { ComponentType, ReactNode } from "react";
 import { NextComponentType, NextPageContext } from "next";
 import { AppProps as DefaultAppProps } from "next/app";
 import { MDXProvider } from "@mdx-js/react";
-import { ThemeProvider } from "../components/theme";
+import { ThemeProvider } from "../components/Theme";
 import { Navbar } from "../components/Navbar";
 import { Footer } from "../components/Footer";
 import { Link } from "../components/Link";
@@ -16,7 +16,7 @@ export default function App({ Component, pageProps }: AppProps): JSX.Element {
   const Layout = Component.Layout ?? DefaultLayout;
 
   return (
-    <ThemeProvider theme="light">
+    <ThemeProvider>
       <MDXProvider components={{ a: Link }}>
         <div className={styles.appContainer}>
           <Navbar />

pages/about/index.module.css

@@ -9,12 +9,12 @@
 }
 
 .content {
-  color: black;
-  background-color: white;
+  color: var(--text);
+  background-color: var(--primary-background);
 }
 
 .content span {
-  color: var(--blue-2);
+  color: var(--primary-accent);
 }
 
 .titleContainer {

pages/about/our-supporters.module.css

@@ -3,18 +3,18 @@
   flex-direction: row;
   align-items: flex-end;
   padding-bottom: 1rem;
-  border-bottom: calc(1rem / 16) solid var(--purple-2);
+  border-bottom: calc(1rem / 16) solid var(--primary-heading);
 }
 
 .header {
-  color: var(--purple-2);
+  color: var(--primary-heading);
   margin: 0 1rem 0 0;
   text-align: center;
 }
 
 .content h2 {
   font-size: calc(24rem / 16);
-  color: var(--blue-2);
+  color: var(--primary-accent);
 }
 
 @media only screen and (max-width: calc(768rem / 16)) {

pages/get-involved.module.css

@@ -5,16 +5,16 @@
 .page > header {
   display: flex;
   flex-direction: row;
-  border-bottom: calc(1rem / 16) solid var(--purple-2);
+  border-bottom: calc(1rem / 16) solid var(--primary-heading);
 }
 
 .headerText > h1 {
-  color: var(--purple-2);
+  color: var(--primary-heading);
   margin: 0 0 calc(8rem / 16) 0;
 }
 
 .headerText > p {
-  color: var(--black);
+  color: var(--text);
   margin: 0 0 calc(22rem / 16) 0;
 }
 
@@ -27,7 +27,7 @@
 }
 
 .content h2 {
-  color: var(--blue-2);
+  color: var(--primary-accent);
 }
 
 .content strong {
@@ -60,7 +60,7 @@
   }
 
   .headerText > h1 {
-    color: var(--purple-2);
+    color: var(--primary-heading);
     font-size: calc(24rem / 16);
     margin-bottom: (12rem / 16);
   }

pages/index.module.css

@@ -47,13 +47,13 @@
   font-family: "Futura", "sans-serif";
   font-size: calc(33rem / 16);
   text-align: center;
-  color: var(--home-title-purple);
+  color: var(--primary-heading);
 }
 
 .clubDescription {
   margin-bottom: calc(50rem / 16);
   text-align: center;
-  color: var(--purple-2);
+  color: var(--primary-heading);
 }
 
 .clubDescription br {
@@ -71,7 +71,7 @@
   margin: 0;
   width: 100%;
 
-  background-color: var(--off-white);
+  background-color: var(--secondary-background);
 }
 
 .cards {
@@ -154,7 +154,7 @@
 
   .clubDescription {
     margin: calc(8rem / 16) 0 calc(26rem / 16);
-    color: var(--purple-2);
+    color: var(--primary-heading);
   }
 
   .clubDescription br {
@@ -196,6 +196,6 @@
     margin: 1rem 0 calc(34rem / 16);
     height: calc(1rem / 16);
     border: none;
-    background-color: var(--purple-2);
+    background-color: var(--primary-heading);
   }
 }

pages/themer.module.css

@@ -0,0 +1,38 @@
+.page {
+  margin-bottom: calc(60rem / 16);
+}
+
+.controls {
+  display: flex;
+  justify-content: space-between;
+}
+
+.controls > *:first-child {
+  margin-right: calc(20rem / 16);
+}
+
+.palette {
+  display: grid;
+  grid-template-columns: repeat(auto-fill, minmax(calc(150rem / 16), 1fr));
+  row-gap: calc(20rem / 16);
+  column-gap: calc(40rem / 16);
+}
+
+.palette > * {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+}
+
+.colorSelector {
+  height: calc(75rem / 16);
+}
+
+.colorReset {
+  margin-bottom: calc(10rem / 16);
+  transition-duration: unset;
+}
+
+.colorName {
+  text-align: center;
+}

pages/themer.tsx

@@ -0,0 +1,78 @@
+import React from "react";
+import { useThemeContext, emptyPalette } from "components/Theme";
+import { Input } from "components/Input";
+import { Button } from "components/Button";
+
+import styles from "./themer.module.css";
+
+export default function Themer() {
+  const context = useThemeContext();
+  const palette = context?.theme.palette ?? emptyPalette;
+
+  return (
+    <main className={styles.page}>
+      <h1>Themer</h1>
+      <form onSubmit={(event) => event.preventDefault()}>
+        <div className={styles.controls}>
+          <Button
+            type="reset"
+            onClick={() => {
+              context?.clearSaved();
+              context?.setTheme("light");
+            }}
+          >
+            Reset to light mode
+          </Button>
+          <Button type="submit" onClick={() => context?.save()}>
+            Save
+          </Button>
+        </div>
+        <div className={styles.palette}>
+          {Object.entries(palette).map(([key, value]) => {
+            const color =
+              value.length === 4 && value.startsWith("#")
+                ? `#${value[1].repeat(2)}${value[2].repeat(2)}${value[3].repeat(
+                    2
+                  )}`
+                : value;
+
+            const isValidColor = color.startsWith("#") && color.length === 7;
+
+            return (
+              <div key={key}>
+                <Input
+                  id={`color-${key}`}
+                  type="color"
+                  className={styles.colorSelector}
+                  value={color}
+                  onChange={(event) =>
+                    context?.setTheme({ [key]: event.target.value })
+                  }
+                />
+                <Button
+                  type="button"
+                  className={styles.colorReset}
+                  size="small"
+                  onClick={() => context?.setTheme({ [key]: "" })}
+                >
+                  Reset
+                </Button>
+                <code className={styles.colorName}>
+                  <label htmlFor={`color-${key}`}>
+                    {!isValidColor && "🚧 "}
+                    {key
+                      .slice(2)
+                      .split("-")
+                      .map((word) => word[0].toUpperCase() + word.slice(1))
+                      .join(" ")}
+                    {!isValidColor && " 🚧"}
+                  </label>
+                </code>
+              </div>
+            );
+          })}
+        </div>{" "}
+      </form>
+    </main>
+  );
+}