implemented article composer functionality + interface, login & signup functionality + interface, auth permission functionality reflected in the nav, and determined a unified accent color accessible in dark and light mode

compose.php

@@ -1,7 +1,61 @@
 <?php
 require_once 'functions/init.php';
 require_once 'functions/functions.php';
-include_once 'components/head.php';
 include_once 'functions/article_functions.php';
 
+if (!empty($_POST)) {
+    $id = create_article(2025, $_POST['title'], $_POST['excerpt'], $_POST['tags'], $_POST['markdown']);
+    header('Location: articles.php?article_id=' . $id);
+}
+
+include_once 'components/head.php';
+
+echo form();
 include_once 'components/foot.php';
+
+function form()
+{
+    $raw_tags = article_tags();
+    $tags = '
+      <div class="form_tags">
+        <label>Tags</label>
+    ';
+
+    foreach ($raw_tags as $row) {
+        $tags .= '
+          <label class="form_checkbox_container">' . $row['tag'] . '
+            <input name="tags[]" value="' . $row['tag_id'] . '" type="checkbox">
+            <span class="checkmark"></span>
+          </label>
+        ';
+    }
+
+    $tags .= '
+      </div>
+    ';
+
+    $form = '
+  <div class="form_card">
+    <form method="post">
+      <label for="title">Title</label>
+      <input id="title" name="title" placeholder="Article Title" required>
+      
+      <label for="markdown">Markdown</label>
+      <textarea id="markdown" name="markdown" required>
+## Heading
+vintagecoding.net uses markdown for articles. This means:
+- Simple syntax for formatting
+- Pre-built styling
+- Markdown can be parsed into HTML.
+      </textarea>
+
+      <label for="excerpt">Excerpt</label>
+      <input id="excerpt" name="excerpt" placeholder="Article Excerpt">
+' . $tags . '
+      <input class="button" type="submit" value="Create Article">
+    </form>
+  </div>
+';
+
+    return $form;
+}