diff --git a/components/OAuth2Page/OAuth2Page.module.scss b/components/OAuth2Page/OAuth2Page.module.scss
index 40fcc82..def59ab 100644
--- a/components/OAuth2Page/OAuth2Page.module.scss
+++ b/components/OAuth2Page/OAuth2Page.module.scss
@@ -4,7 +4,7 @@
   border-radius: 8px;
   gap: 1rem;
   padding: 0.5rem;
-  box-shadow: 0 0 8px rgba(0, 0, 0, 0.25);
+  box-shadow: 0 0 8px var(--box-shadow-color);
 
   .titleWrap {
     display: flex;
diff --git a/components/OAuth2Page/OAuth2Page.tsx b/components/OAuth2Page/OAuth2Page.tsx
index be6a2b6..4ac2989 100644
--- a/components/OAuth2Page/OAuth2Page.tsx
+++ b/components/OAuth2Page/OAuth2Page.tsx
@@ -27,7 +27,7 @@ import { FormControl } from '../common/Form/FormControl/FormControl';
 import toast from 'react-hot-toast';
 import { Button } from '../common/Button/Button';
 import userHasPrivileges from '../../lib/utils/has-privileges';
-import { publishJSON } from '../../lib/utils/swr-fetcher';
+import { publishJSON } from '../../lib/utils/fetch';
 
 const LINK_NAMES = {
   redirect_uri: 'Redirect URI',
diff --git a/components/UsersPage/UsersPage.module.scss b/components/UsersPage/UsersPage.module.scss
index f6bf6d4..4a17570 100644
--- a/components/UsersPage/UsersPage.module.scss
+++ b/components/UsersPage/UsersPage.module.scss
@@ -4,7 +4,7 @@
   border-radius: 8px;
   gap: 1rem;
   padding: 0.5rem;
-  box-shadow: 0 0 8px rgba(0, 0, 0, 0.25);
+  box-shadow: 0 0 8px var(--box-shadow-color);
 
   .titleWrap {
     display: flex;
diff --git a/components/UsersPage/UsersPage.tsx b/components/UsersPage/UsersPage.tsx
index 1ae7ab4..0b1403d 100644
--- a/components/UsersPage/UsersPage.tsx
+++ b/components/UsersPage/UsersPage.tsx
@@ -12,7 +12,7 @@ import { UPLOADS_URL } from '../../lib/constants';
 import { Paginator } from '../common/Paginator/Paginator';
 import { Dropdown } from '../common/Dropdown/Dropdown';
 import toast from 'react-hot-toast';
-import { publishJSON } from '../../lib/utils/swr-fetcher';
+import { publishJSON } from '../../lib/utils/fetch';
 import { useForm } from '../../lib/hooks/useForm';
 import { ModalProps } from '../../lib/types/modal.interface';
 import { Button } from '../common/Button/Button';
diff --git a/components/common/Button/Button.module.scss b/components/common/Button/Button.module.scss
index a03d5c1..9fcbc10 100644
--- a/components/common/Button/Button.module.scss
+++ b/components/common/Button/Button.module.scss
@@ -2,70 +2,68 @@
   appearance: none;
   padding: 0.5rem 1.5rem;
   border-radius: 4px;
-  transition: background linear 0.33s;
+  transition: background linear 0.15s;
+
+  --btn-background: transparent;
+  --btn-color: #000;
+  --btn-border: #ddd;
+
+  color: var(--btn-color);
+  background: var(--btn-background);
+  border: 1px solid var(--btn-border);
 
   &:not([disabled]) {
     cursor: pointer;
   }
 
   &.default {
-    border: 1px solid #b9b9b9;
-    background: linear-gradient(
-      180deg,
-      rgb(246 246 246) 0%,
-      rgb(241 241 241) 100%
-    );
+    --btn-color: var(--button-default-color);
+    --btn-border: var(--button-default-border);
+    --btn-background: var(--button-default-background);
+
+    &[disabled] {
+      --btn-background: var(--button-default-disabled);
+      --btn-color: var(--button-default-disabled-color);
+    }
 
     &:not([disabled]) {
       &:hover,
       &:focus-visible {
-        background: linear-gradient(
-          180deg,
-          rgb(255 255 255) 0%,
-          rgb(250 250 250) 100%
-        );
+        --btn-background: var(--button-default-hover);
       }
 
       &:active {
-        background: linear-gradient(
-          180deg,
-          rgb(241 241 241) 0%,
-          rgb(246 246 246) 100%
-        );
+        --btn-background: var(--button-default-active);
       }
     }
   }
+
   &.primary {
-    border: 1px solid #00aaff;
-    background: linear-gradient(
-      180deg,
-      rgb(133 216 255) 0%,
-      rgba(59, 190, 255, 1) 100%
-    );
+    --btn-color: var(--button-primary-color);
+    --btn-border: 1px solid var(--button-primary-border);
+    --btn-background: var(--button-primary-background);
+
+    &[disabled] {
+      --btn-background: var(--button-primary-disabled);
+      --btn-color: var(--button-primary-disabled-color);
+    }
 
     &:not([disabled]) {
       &:hover,
       &:focus-visible {
-        background: linear-gradient(
-          180deg,
-          rgb(145 220 255) 0%,
-          rgb(84 198 255) 100%
-        );
+        --btn-background: var(--button-primary-hover);
       }
 
       &:active {
-        background: linear-gradient(
-          180deg,
-          rgb(77, 196, 255) 0%,
-          rgb(124, 213, 255) 100%
-        );
+        --btn-background: var(--button-primary-active);
       }
     }
   }
+
   &.link {
-    border: 0;
-    background: transparent;
-    color: #0090d8;
+    --btn-border: transparent;
+    --btn-background: transparent;
+    --btn-color: var(--button-link-color);
 
     &:not([disabled]) {
       &:hover,
diff --git a/components/common/Container/Container.module.scss b/components/common/Container/Container.module.scss
index 83706ad..824212c 100644
--- a/components/common/Container/Container.module.scss
+++ b/components/common/Container/Container.module.scss
@@ -2,6 +2,6 @@
   max-width: 1080px;
   margin: 0 auto;
   padding: 1rem;
-  background-color: #fff;
+  background-color: var(--container-main);
   min-height: calc(100vh - 54px);
 }
diff --git a/components/common/Dropdown/Dropdown.module.scss b/components/common/Dropdown/Dropdown.module.scss
index f59686c..5299a25 100644
--- a/components/common/Dropdown/Dropdown.module.scss
+++ b/components/common/Dropdown/Dropdown.module.scss
@@ -3,8 +3,9 @@
 
   .toggle {
     appearance: none;
-    border: 1px solid #ddd;
-    background: #ffffff;
+    border: 1px solid var(--container-main-border);
+    transition: background-color linear 0.15s;
+    background-color: var(--container-main);
     border-radius: 4px;
     width: 32px;
     height: 32px;
@@ -13,7 +14,7 @@
     &.active,
     &:hover,
     &:focus-visible {
-      background-color: rgb(240, 240, 240);
+      background-color: var(--container-main-secondary);
     }
 
     &.active {
@@ -35,8 +36,8 @@
     flex-direction: column;
     top: 100%;
     min-width: 140px;
-    background-color: #fff;
-    border: 1px solid #ddd;
+    background-color: var(--container-main);
+    border: 1px solid var(--container-main-border);
     border-radius: 4px;
 
     a,
@@ -44,10 +45,11 @@
       appearance: none;
       border: 0;
       background: transparent;
+      transition: background-color linear 0.15s;
       font-size: 1rem;
       text-align: left;
       padding: 0.5rem 0.5rem;
-      border-bottom: 1px solid #ddd;
+      border-bottom: 1px solid var(--container-main-border);
       cursor: pointer;
 
       &:hover,
diff --git a/components/common/Form/Form.module.scss b/components/common/Form/Form.module.scss
index 45536b4..4f1a164 100644
--- a/components/common/Form/Form.module.scss
+++ b/components/common/Form/Form.module.scss
@@ -32,13 +32,15 @@
     font-size: 14px;
     font-family: inherit;
     font-weight: 400;
-    border: 1px solid #a4a4a4;
-    box-shadow: inset 0 0 4px #0000001f;
+    color: var(--form-field-color);
+    background: var(--form-field-background);
+    border: 1px solid var(--form-field-border);
+    box-shadow: inset 0 0 4px var(--form-field-box-shadow);
 
     + span {
       font-size: 0.875rem;
       margin-top: 0.25rem;
-      color: rgb(100, 100, 100);
+      color: var(--form-field-helper-color);
     }
   }
 
diff --git a/components/common/Header/Header.module.scss b/components/common/Header/Header.module.scss
index e38459e..4290802 100644
--- a/components/common/Header/Header.module.scss
+++ b/components/common/Header/Header.module.scss
@@ -1,13 +1,15 @@
 .nav {
   display: flex;
-  background-color: #2eb9ff;
-  border-bottom: 4px solid #00aaff;
+  color: var(--nav-text-color);
+  background-color: var(--nav-main-color);
+  border-bottom: 4px solid var(--nav-secondary-color);
 
   .inner {
     display: flex;
     max-width: 1080px;
     width: 100%;
     margin: 0 auto;
+
     ul {
       list-style: none;
       display: flex;
@@ -26,7 +28,7 @@
           font-weight: bold;
 
           a {
-            background-color: #00aaff;
+            background-color: var(--nav-secondary-color);
           }
         }
 
diff --git a/components/common/Modal/Modal/Modal.module.scss b/components/common/Modal/Modal/Modal.module.scss
index 8f7a323..ada321a 100644
--- a/components/common/Modal/Modal/Modal.module.scss
+++ b/components/common/Modal/Modal/Modal.module.scss
@@ -3,14 +3,15 @@
   flex-direction: column;
   max-width: 480px;
   margin: 0 auto;
-  background-color: #fff;
+  background-color: var(--container-main);
   margin-top: 8%;
   border-radius: 8px;
-  box-shadow: 0 8px 32px #0000006b;
+  box-shadow: 0 8px 32px var(--modal-shadow-color);
+  color: var(--text-color-main);
 
   .header {
     padding: 1rem;
-    border-bottom: 1px solid #ddd;
+    border-bottom: 1px solid var(--container-main-border);
     display: flex;
     justify-content: space-between;
 
@@ -29,7 +30,7 @@
 
   .footer {
     padding: 1rem;
-    border-top: 1px solid #ddd;
+    border-top: 1px solid var(--container-main-border);
     gap: 0.5rem;
     display: flex;
     justify-content: flex-end;
diff --git a/lib/api/remote.ts b/lib/api/remote.ts
index 831ed1a..c06ce0b 100644
--- a/lib/api/remote.ts
+++ b/lib/api/remote.ts
@@ -1,8 +1,24 @@
-import { API_URL } from '../constants';
-import { CurrentUserDto } from '../types/user-response.interface';
-import { fetchBearer, fetchToken } from '../utils/fetch';
+import { API_URL, CLIENT_ID, CLIENT_SECRET, TOKEN_URL } from '../constants';
 
 export const getUserInfo = async (accessToken: string) =>
-  await fetchBearer<CurrentUserDto>(accessToken, `${API_URL}/user`);
+  fetch(`${API_URL}/user`, {
+    headers: {
+      Authorization: `Bearer ${accessToken}`,
+      'Content-Type': 'application/json',
+    },
+  }).then((res) => res.json());
 
-export const getAccessToken = async (code: string) => await fetchToken(code);
+export const getAccessToken = async (code: string) =>
+  fetch(TOKEN_URL, {
+    headers: {
+      Authorization: `Basic ${Buffer.from(
+        `${CLIENT_ID}:${CLIENT_SECRET}`
+      ).toString('base64')}`,
+      'Content-Type': 'application/json',
+    },
+    method: 'POST',
+    body: JSON.stringify({
+      grant_type: 'authorization_code',
+      code,
+    }),
+  }).then((res) => res.json());
diff --git a/lib/utils/fetch.ts b/lib/utils/fetch.ts
index e26a338..3dc8c45 100644
--- a/lib/utils/fetch.ts
+++ b/lib/utils/fetch.ts
@@ -1,32 +1,68 @@
-import { CLIENT_ID, CLIENT_SECRET, TOKEN_URL } from '../constants';
-import { OAuth2TokenDto } from '../types/token-response.interface';
+export default async function fetchJson<JSON = unknown>(
+  input: RequestInfo,
+  init?: RequestInit
+): Promise<JSON> {
+  const response = await fetch(input, { ...init, credentials: 'include' });
 
-export async function fetchBearer<T>(
-  accessToken: string,
-  url: string,
-  ...options: any[]
-): Promise<T> {
-  return fetch(url, {
-    headers: {
-      Authorization: `Bearer ${accessToken}`,
-      'Content-Type': 'application/json',
-    },
-    ...options,
-  }).then((res) => res.json());
+  // if the server replies, there's always some data in json
+  // if there's a network error, it will throw at the previous line
+  const data = await response.json();
+
+  // response.ok is true when res.status is 2xx
+  // https://developer.mozilla.org/en-US/docs/Web/API/Response/ok
+  if (response.ok) {
+    return data;
+  }
+
+  throw new FetchError({
+    message: response.statusText,
+    response,
+    data,
+  });
 }
 
-export async function fetchToken(code: string): Promise<OAuth2TokenDto> {
-  return fetch(TOKEN_URL, {
+export async function publishJSON(
+  input: RequestInfo,
+  method: string = 'POST',
+  body?: Object,
+  init?: RequestInit
+) {
+  return fetchJson(input, {
+    ...init,
+    method,
     headers: {
-      Authorization: `Basic ${Buffer.from(
-        `${CLIENT_ID}:${CLIENT_SECRET}`
-      ).toString('base64')}`,
       'Content-Type': 'application/json',
     },
-    method: 'POST',
-    body: JSON.stringify({
-      grant_type: 'authorization_code',
-      code,
-    }),
-  }).then((res) => res.json());
+    body: JSON.stringify(body),
+  });
+}
+
+export class FetchError extends Error {
+  response: Response;
+  data: {
+    message: string;
+  };
+  constructor({
+    message,
+    response,
+    data,
+  }: {
+    message: string;
+    response: Response;
+    data: {
+      message: string;
+    };
+  }) {
+    // Pass remaining arguments (including vendor specific ones) to parent constructor
+    super(message);
+
+    // Maintains proper stack trace for where our error was thrown (only available on V8)
+    if (Error.captureStackTrace) {
+      Error.captureStackTrace(this, FetchError);
+    }
+
+    this.name = 'FetchError';
+    this.response = response;
+    this.data = data ?? { message: message };
+  }
 }
diff --git a/lib/utils/swr-fetcher.ts b/lib/utils/swr-fetcher.ts
deleted file mode 100644
index 3dc8c45..0000000
--- a/lib/utils/swr-fetcher.ts
+++ /dev/null
@@ -1,68 +0,0 @@
-export default async function fetchJson<JSON = unknown>(
-  input: RequestInfo,
-  init?: RequestInit
-): Promise<JSON> {
-  const response = await fetch(input, { ...init, credentials: 'include' });
-
-  // if the server replies, there's always some data in json
-  // if there's a network error, it will throw at the previous line
-  const data = await response.json();
-
-  // response.ok is true when res.status is 2xx
-  // https://developer.mozilla.org/en-US/docs/Web/API/Response/ok
-  if (response.ok) {
-    return data;
-  }
-
-  throw new FetchError({
-    message: response.statusText,
-    response,
-    data,
-  });
-}
-
-export async function publishJSON(
-  input: RequestInfo,
-  method: string = 'POST',
-  body?: Object,
-  init?: RequestInit
-) {
-  return fetchJson(input, {
-    ...init,
-    method,
-    headers: {
-      'Content-Type': 'application/json',
-    },
-    body: JSON.stringify(body),
-  });
-}
-
-export class FetchError extends Error {
-  response: Response;
-  data: {
-    message: string;
-  };
-  constructor({
-    message,
-    response,
-    data,
-  }: {
-    message: string;
-    response: Response;
-    data: {
-      message: string;
-    };
-  }) {
-    // Pass remaining arguments (including vendor specific ones) to parent constructor
-    super(message);
-
-    // Maintains proper stack trace for where our error was thrown (only available on V8)
-    if (Error.captureStackTrace) {
-      Error.captureStackTrace(this, FetchError);
-    }
-
-    this.name = 'FetchError';
-    this.response = response;
-    this.data = data ?? { message: message };
-  }
-}
diff --git a/pages/_app.tsx b/pages/_app.tsx
index 0255671..3c6bdcf 100644
--- a/pages/_app.tsx
+++ b/pages/_app.tsx
@@ -1,7 +1,7 @@
 import '../styles/globals.scss';
 import type { AppProps } from 'next/app';
 import { SWRConfig } from 'swr';
-import fetchJson from '../lib/utils/swr-fetcher';
+import fetchJson from '../lib/utils/fetch';
 import ModalRoot from '../components/common/Modal/ModalRoot/ModalRoot';
 import { Toaster } from 'react-hot-toast';
 
diff --git a/styles/_colors.scss b/styles/_colors.scss
new file mode 100644
index 0000000..7e95380
--- /dev/null
+++ b/styles/_colors.scss
@@ -0,0 +1,40 @@
+:root {
+  --text-color-main: #000;
+  --background-main: rgb(231, 231, 231);
+  --container-main: #fff;
+  --container-main-border: #ddd;
+  --container-main-secondary: rgb(240, 240, 240);
+
+  --link-text-color: #0090d8;
+
+  --nav-text-color: #000;
+  --nav-main-color: #2eb9ff;
+  --nav-secondary-color: #00aaff;
+
+  --box-shadow-color: rgb(0 0 0 / 25%);
+  --modal-shadow-color: rgb(0 0 0 / 42%);
+
+  --button-default-color: #000;
+  --button-default-border: #b9b9b9;
+  --button-default-background: rgb(246 246 246);
+  --button-default-disabled: #ebebeb;
+  --button-default-disabled-color: #939393;
+  --button-default-hover: rgb(250 250 250);
+  --button-default-active: rgb(226, 226, 226);
+
+  --button-primary-color: #000;
+  --button-primary-border: #00aaff;
+  --button-primary-background: rgb(90, 200, 255);
+  --button-primary-disabled: rgb(39 131 177);
+  --button-primary-disabled-color: #484848;
+  --button-primary-hover: rgb(114, 208, 255);
+  --button-primary-active: rgb(70, 196, 255);
+
+  --button-link-color: #0090d8;
+
+  --form-field-color: #000;
+  --form-field-background: #fff;
+  --form-field-border: #a4a4a4;
+  --form-field-box-shadow: #0000001f;
+  --form-field-helper-color: rgb(100, 100, 100);
+}
diff --git a/styles/globals.scss b/styles/globals.scss
index d3f44ef..87e7bf9 100644
--- a/styles/globals.scss
+++ b/styles/globals.scss
@@ -1,3 +1,4 @@
+@import 'colors';
 @import 'breakpoint';
 @import 'focus';
 
@@ -7,11 +8,12 @@ body {
   margin: 0;
   font-family: -apple-system, BlinkMacSystemFont, Segoe UI, Roboto, Oxygen,
     Ubuntu, Cantarell, Fira Sans, Droid Sans, Helvetica Neue, sans-serif;
-  background-color: rgb(231, 231, 231);
+  background-color: var(--background-main);
+  color: var(--text-color-main);
 }
 
 a {
-  color: #00aaff;
+  color: var(--link-text-color);
   text-decoration: none;
 
   &:hover {
@@ -39,13 +41,3 @@ dl {
     margin-top: 0.5rem;
   }
 }
-
-@media (prefers-color-scheme: dark) {
-  html {
-    color-scheme: dark;
-  }
-  body {
-    color: white;
-    background: black;
-  }
-}