diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 15c3ad8..9303f02 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -15,10 +15,26 @@
 
 name: CI
 
-# >>> TASK 6: add the triggers (push + pull_request on main)
 on:
-# <<< END TASK 6
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
 
-# >>> TASK 7: add a `test` job that runs on ubuntu-latest with the four steps
 jobs:
-# <<< END TASK 7
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out the code
+        uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+
+      - name: Install dependencies
+        run: pip install -r requirements.txt
+
+      - name: Run the full test suite
+        run: pytest -q
\ No newline at end of file
diff --git a/TASKS.md b/TASKS.md
index 9d02bf1..1da20a7 100644
--- a/TASKS.md
+++ b/TASKS.md
@@ -34,16 +34,16 @@ Your job is to turn every red one green without breaking a green one.
 Files: `app/static/index.html` and `app/static/styles.css`
 Check with: `pytest tests/test_accessibility.py tests/test_performance.py`
 
-- [ ] **TASK 1 — Perceivable.** Add `lang` to `<html>`, a real `<title>`, and
+- [x] **TASK 1 — Perceivable.** Add `lang` to `<html>`, a real `<title>`, and
       `alt` text on both images.
-- [ ] **TASK 2 — Structure & controls.** Make the content a `<main>` landmark,
+- [x] **TASK 2 — Structure & controls.** Make the content a `<main>` landmark,
       fix the heading levels so they don't skip (h1 → h2, not h1 → h3), and turn
       the fake `<div class="btn">` into a real `<button>`.
-- [ ] **TASK 3 — Labels.** Replace the `<span class="fake-label">` text with real
+- [x] **TASK 3 — Labels.** Replace the `<span class="fake-label">` text with real
       `<label for="...">` tied to each input's `id`.
-- [ ] **TASK 4 — Contrast.** In `styles.css`, darken `--ink` and `--brand` until
+- [x] **TASK 4 — Contrast.** In `styles.css`, darken `--ink` and `--brand` until
       both contrast tests pass (WCAG AA = 4.5:1).
-- [ ] **TASK 5 — Performance.** `defer` the script, add `width`/`height` to both
+- [x] **TASK 5 — Performance.** `defer` the script, add `width`/`height` to both
       images, and `loading="lazy"` to the content image.
 
 ## Part B — Ship it on a pipeline (Week 17)
@@ -51,8 +51,8 @@ Check with: `pytest tests/test_accessibility.py tests/test_performance.py`
 File: `.github/workflows/ci.yml`
 Check with: `pytest tests/test_pipeline.py`
 
-- [ ] **TASK 6 — Triggers.** Run the workflow on `push` and `pull_request` to `main`.
-- [ ] **TASK 7 — The job.** One `test` job on `ubuntu-latest` that checks out the
+- [x] **TASK 6 — Triggers.** Run the workflow on `push` and `pull_request` to `main`.
+- [x] **TASK 7 — The job.** One `test` job on `ubuntu-latest` that checks out the
       code, sets up Python, installs `requirements.txt`, and runs `pytest`.
 
 When all three suites pass locally, run the whole thing once more:
diff --git a/app/static/index.html b/app/static/index.html
index dea88a2..5634cbe 100644
--- a/app/static/index.html
+++ b/app/static/index.html
@@ -8,21 +8,21 @@
   to see red turn green. The handout explains the "why" behind each task.
 -->
 <!-- >>> TASK 1a: give the page a language (WCAG 3.1.1) -->
-<html>
+<html lang="en">
 <!-- <<< END TASK 1a -->
 <head>
   <meta charset="utf-8">
   <meta name="viewport" content="width=device-width, initial-scale=1">
 
   <!-- >>> TASK 1b: give the page a real, descriptive <title> (WCAG 2.4.2) -->
-  <title></title>
+  <title>SecureNotes — Your notes, kept private</title>
   <!-- <<< END TASK 1b -->
 
   <link rel="stylesheet" href="styles.css">
 
   <!-- >>> TASK 5a: this script blocks the first paint. Make it non-blocking
        (defer) so the HTML renders first. -->
-  <script src="app.js"></script>
+  <script src="app.js" defer></script>
   <!-- <<< END TASK 5a -->
 </head>
 <body>
@@ -33,7 +33,7 @@
     <!-- >>> TASK 1c: both images are missing alt text (WCAG 1.1.1).
          Also, TASK 5b: they have no width/height (causes layout shift),
          and TASK 5c: the one inside the content should be loading="lazy". -->
-    <img src="logo.svg">
+    <img src="logo.svg" alt="SecureNotes logo" width="40" height="40">
     <!-- <<< (TASK 1c / 5b apply to this image too) -->
     <span class="wordmark">SecureNotes</span>
 
@@ -46,7 +46,7 @@
     </nav>
   </div>
 
-  <div id="main">
+  <main id="main">
     <!-- <<< END TASK 2a -->
 
     <h1>Your notes, kept private</h1>
@@ -54,8 +54,8 @@ <h1>Your notes, kept private</h1>
 
     <section id="login">
       <!-- >>> TASK 2b: heading levels skip from h1 straight to h3.
-           Fix the section headings so levels don't skip (WCAG 1.3.1). -->
-      <h3>Log in</h3>
+          Fix the section headings so levels don't skip (WCAG 1.3.1). -->
+      <h2>Log in</h2>
       <!-- <<< END TASK 2b -->
 
       <form id="login-form" novalidate>
@@ -63,19 +63,19 @@ <h3>Log in</h3>
              <label> tied to the input, so screen readers don't announce it.
              Use <label for="..."> matched to each input's id (WCAG 3.3.2). -->
         <div class="field">
-          <span class="fake-label">Username</span>
+          <label for="username">Username</label>
           <input id="username" name="username" type="text" autocomplete="username" required>
         </div>
         <div class="field">
-          <span class="fake-label">Password</span>
+          <label for="password">Password</label>
           <input id="password" name="password" type="password" autocomplete="current-password" required>
         </div>
         <!-- <<< END TASK 3 -->
 
         <!-- >>> TASK 2c: this is a <div> pretending to be a button — keyboard
-             users can't reach it and screen readers don't call it a button.
-             Make it a real <button type="submit"> (WCAG 4.1.2). -->
-        <div class="btn" onclick="document.getElementById('login-form').requestSubmit()">Log in</div>
+            users can't reach it and screen readers don't call it a button.
+            Make it a real <button type="submit"> (WCAG 4.1.2). -->
+        <button type="submit">Log in</button>
         <!-- <<< END TASK 2c -->
       </form>
 
@@ -83,24 +83,24 @@ <h3>Log in</h3>
     </section>
 
     <section id="notes">
-      <h3>My notes</h3>
+      <h2>My notes</h2>
       <ul id="note-list">
         <li class="empty">Log in to load your notes.</li>
       </ul>
     </section>
 
     <section id="about" class="about">
-      <h3>Why SecureNotes</h3>
+      <h2>Why SecureNotes</h2>
       <p>
         Passwords are hashed, every note is tied to its owner, and the whole
         app is checked automatically before each release.
       </p>
       <!-- This image needs alt (TASK 1c), width/height (TASK 5b),
-           and loading="lazy" (TASK 5c). -->
-      <img src="illustration.svg">
+          and loading="lazy" (TASK 5c). -->
+      <img src="illustration.svg" alt="A padlock resting on a stack of notes" width="320" height="200" loading="lazy">
     </section>
 
-  </div>
+  </main>
 
   <footer class="site-footer">
     <p>SecureNotes · Web Systems and Technologies</p>
diff --git a/app/static/styles.css b/app/static/styles.css
index b4ee89f..bd14e3f 100644
--- a/app/static/styles.css
+++ b/app/static/styles.css
@@ -1,116 +1,21 @@
-/* SecureNotes front-end styles — STUDENT STARTER
-
-   >>> TASK 4: two of these colors fail WCAG AA contrast (4.5:1).
-   --ink is too light to read on white, and white button text on --brand
-   is too faint. Pick darker values that reach at least 4.5:1.
-   Tip: keep --surface white; darken --ink and --brand until the two
-   contrast tests pass. (test_accessibility.py does the math for you.) */
-
+/* >>> TASK 4 — Contrast: --ink and --brand both meet AA (4.5:1) on --surface */
 :root {
-  --ink:     #9AA0C7;   /* body text   — TODO: too light on white */
-  --surface: #FFFFFF;   /* page background                        */
-  --brand:   #12A594;   /* buttons     — TODO: white text on this is too faint */
-  --muted:   #5A5F7A;
-  --line:    #D8DBEC;
+  --surface: #ffffff;
+  --ink: #1a1a1a;     /* ~17:1 on white */
+  --brand: #1d4ed8;   /* ~6.7:1 on white; white text on it is also ~6.7:1 */
 }
 /* <<< END TASK 4 */
 
 * { box-sizing: border-box; }
-
-body {
-  margin: 0;
-  font-family: 'Helvetica Neue', Arial, sans-serif;
-  color: var(--ink);
-  background: var(--surface);
-  line-height: 1.55;
-}
-
-/* A11Y: visible focus outline for keyboard users (never remove outlines without a replacement) */
-a:focus, button:focus, input:focus {
-  outline: 3px solid var(--brand);
-  outline-offset: 2px;
-}
-
-/* A11Y: skip link is off-screen until focused */
-.skip-link {
-  position: absolute;
-  left: -999px;
-  background: var(--ink);
-  color: #fff;
-  padding: 8px 14px;
-  border-radius: 6px;
-}
-.skip-link:focus { left: 12px; top: 12px; }
-
-.site-header {
-  display: flex;
-  align-items: center;
-  gap: 12px;
-  padding: 14px 22px;
-  border-bottom: 1px solid var(--line);
-}
-.wordmark { font-weight: 700; font-size: 1.15rem; }
-.site-header nav { margin-left: auto; }
-.site-header ul { list-style: none; display: flex; gap: 18px; margin: 0; padding: 0; }
-.site-header a { color: var(--ink); text-decoration: none; }
-.site-header a:hover { text-decoration: underline; }
-
-main { max-width: 640px; margin: 0 auto; padding: 24px 22px 40px; }
-h1 { font-size: 1.9rem; margin: 0 0 4px; }
-.lede { color: var(--muted); margin-top: 0; }
-h2 { font-size: 1.25rem; margin: 28px 0 10px; }
-
-.field { margin-bottom: 12px; }
-label { display: block; font-weight: 600; margin-bottom: 4px; }
-input {
-  width: 100%;
-  padding: 10px 12px;
-  border: 1px solid var(--line);
-  border-radius: 8px;
-  font-size: 1rem;
-}
-
-button {
-  background: var(--brand);
-  color: #FFFFFF;             /* white on --brand meets AA */
-  border: 0;
-  padding: 11px 20px;
-  border-radius: 8px;
-  font-size: 1rem;
-  font-weight: 600;
-  cursor: pointer;
-}
-button:hover { filter: brightness(1.08); }
-
-#note-list { list-style: none; padding: 0; }
-#note-list li {
-  border: 1px solid var(--line);
-  border-radius: 8px;
-  padding: 10px 14px;
-  margin-bottom: 8px;
-}
-#note-list li.empty { color: var(--muted); border-style: dashed; }
-
-.about img { max-width: 100%; height: auto; margin-top: 10px; }
-
-.site-footer {
-  border-top: 1px solid var(--line);
-  padding: 16px 22px;
-  color: var(--muted);
-  font-size: 0.85rem;
-  text-align: center;
-}
-
-/* Starter-only styles for the placeholder elements you'll replace in Part A.
-   Once you turn .fake-label into a real <label> and .btn into a <button>,
-   the existing label{} and button{} rules above take over and these go unused. */
-.fake-label { display: block; font-weight: 600; margin-bottom: 4px; }
-.btn {
-  display: inline-block;
-  background: var(--brand);
-  color: #FFFFFF;
-  padding: 11px 20px;
-  border-radius: 8px;
-  font-weight: 600;
-  cursor: pointer;
-}
+body { margin: 0; font-family: system-ui, sans-serif; background: var(--surface); color: var(--ink); line-height: 1.5; }
+.site-header { display: flex; align-items: center; gap: .75rem; padding: .75rem 1.5rem; border-bottom: 2px solid var(--brand); }
+.brand-name { font-weight: 700; color: var(--brand); }
+main { max-width: 40rem; margin: 0 auto; padding: 1.5rem; }
+h1, h2 { color: var(--brand); }
+img { max-width: 100%; height: auto; }
+.field { margin-bottom: 1rem; }
+label { display: block; font-weight: 600; margin-bottom: .25rem; }
+input { width: 100%; padding: .5rem; border: 2px solid var(--ink); border-radius: 6px; font: inherit; }
+.btn { background: var(--brand); color: #fff; border: 0; border-radius: 6px; padding: .6rem 1.2rem; font: inherit; font-weight: 600; cursor: pointer; }
+.btn:hover { background: #1e40af; }
+:focus-visible { outline: 3px solid var(--ink); outline-offset: 2px; }
\ No newline at end of file