[feature] Nicer login.html page, with cute styling + link to source code (#19)

Fixes #9

- Cute styling, combination of Mastodon and GTS
- Short description of the project
- Error and status messages (temporarily) appear in disabled button with correct ARIA attributes
- Sufficient contrast (WCAG AAA)

Let me know if using `login.scss` both as an index file and for adding custom styling is okay. I figured this might be preferred over creating an extra folder and file.

Reviewed-on: https://codeberg.org/superseriousbusiness/masto-fe-standalone/pulls/19
Co-authored-by: vyxen <vyxen@tutamail.com>
Co-committed-by: vyxen <vyxen@tutamail.com>

app/javascript/flavours/glitch/packs/login.js

@@ -0,0 +1,8 @@
+import 'packs/public-path';
+import { start } from '@rails/ujs';
+import 'flavours/glitch/styles/login.scss';
+
+start();
+
+//  This ensures that webpack compiles our images.
+require.context('../images', true);

app/javascript/flavours/glitch/styles/login.scss

@@ -0,0 +1,118 @@
+@import 'variables';
+@import 'styles/fonts/roboto';
+@import 'styles/fonts/roboto-mono';
+@import 'reset';
+@import 'basics';
+
+body {
+    height: 100vh;
+
+    a {
+        color: #89caff;
+    }
+}
+
+.login-container {
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    justify-content: center;
+    height: 100%;
+    max-width: 30rem;
+    padding: 1rem;
+    margin: auto;
+    box-sizing: border-box;
+}
+
+header {
+    display: flex;
+    justify-content: center;
+    margin-bottom: 1rem;
+}
+
+.mascot {
+    height: 10rem;
+}
+
+main {
+    display: flex;
+    position: relative;
+    flex-direction: column;
+    row-gap: 10px;
+}
+
+.login {
+    display: flex;
+    position: relative;
+    column-gap: 10px;
+}
+
+.instance {
+    background: #282c37;
+    border: 0;
+    border-radius: 4px;
+    box-shadow: none;
+    box-sizing: border-box;
+    color: #9baec8;
+    display: block;
+    font-family: inherit;
+    font-size: 16px;
+    line-height: 18px;
+    margin: 0;
+    outline: 0;
+    padding: 15px;
+    padding-inline-end: 30px;
+    width: 100%;
+}
+
+.button {
+    display: flex;
+    column-gap: .5rem;
+    align-items: center;
+    justify-content: center;
+    background-color: #66befe;
+    border: 0 none;
+    border-radius: 4px;
+    box-sizing: border-box;
+    color: #2a2b2f;
+    cursor: pointer;
+    font-size: 16px;
+    letter-spacing: 0;
+    line-height: 22px;
+    font-family: inherit;
+    font-weight: 500;
+    padding: 7px 10px;
+    position: relative;
+    text-align: center;
+    text-decoration: none;
+    white-space: nowrap;
+    flex-basis: auto;
+
+    &:hover {
+        background-color: #89caff;
+    }
+
+    &:disabled {
+        background-color: #9baec8;
+        cursor: default;
+    }
+}
+
+.content {
+    background-color: #444b5d;
+    padding: 15px;
+    font-size: 1rem;
+    line-height: 1.5rem;
+    border-radius: 4px;
+    display: flex;
+    flex-direction: column;
+    row-gap: .75rem;
+}
+
+.link-footer {
+    padding: 10px;
+
+    p, a {
+        color: #97A8B4;
+    }
+}

app/javascript/flavours/glitch/theme.yml

@@ -16,6 +16,9 @@ pack:
       - flavours/glitch/async/getting_started
       - flavours/glitch/async/home_timeline
       - flavours/glitch/async/notifications
+  login:
+    filename: packs/login.js
+    stylesheet: true
   mailer:
   modal:
   public: packs/public.jsx