feat(ui): Mobile hamburger nav menu

static/css/styles.css

@@ -65,6 +65,7 @@ body {
   display: flex;
   justify-content: space-between;
   align-items: center;
+  position: relative; /* for mobile dropdown positioning */
 }
 
 .logo {
@@ -75,6 +76,10 @@ body {
   transition: transform 0.3s ease;
   letter-spacing: 0.2px;
   font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
+  display: inline-flex;
+  align-items: center;
+  gap: 0.5rem;
+  transform-origin: left center;
 }
 
 .logo:hover {
@@ -85,6 +90,12 @@ body {
   color: var(--accent);
 }
 
+.logo-img {
+  display: block;
+  height: 28px;
+  width: auto;
+}
+
 .nav-links {
   display: flex;
   gap: 2rem;
@@ -115,6 +126,35 @@ body {
   width: 100%;
 }
 
+/* Hamburger toggle (hidden on desktop) */
+.nav-toggle {
+  display: none;
+  flex-direction: column;
+  justify-content: center;
+  align-items: center;
+  gap: 5px;
+  width: 42px;
+  height: 42px;
+  border: 1px solid rgba(2, 6, 23, 0.08);
+  border-radius: 10px;
+  background: #ffffff;
+  cursor: pointer;
+  transition: box-shadow 0.2s ease, transform 0.2s ease;
+}
+
+.nav-toggle:hover {
+  box-shadow: var(--shadow);
+  transform: translateY(-1px);
+}
+
+.nav-toggle .bar {
+  width: 20px;
+  height: 2px;
+  background: var(--text-dark);
+  border-radius: 2px;
+  transition: transform 0.25s ease, opacity 0.25s ease;
+}
+
 /* =======================
    Hero Section (Landing)
    ======================= */
@@ -297,10 +337,24 @@ body {
   text-align: center;
 }
 
+.app-brand {
+  display: inline-flex;
+  align-items: center;
+  gap: 0.5rem;
+  margin-bottom: 0.5rem;
+}
+
+.app-brand-icon {
+  width: 32px;
+  height: 32px;
+  display: block;
+  border-radius: 6px; /* optional */
+}
+
 .app-logo {
   font-size: 2rem;
   font-weight: 700;
-  margin-bottom: 1rem;
+  margin-bottom: 0;
 }
 
 .stats-grid {
@@ -350,8 +404,8 @@ body {
   background: var(--gradient);
   -webkit-background-clip: text;
   -webkit-text-fill-color: transparent;
-          background-clip: text;
-          color: transparent;
+  background-clip: text;
+  color: transparent;
 }
 
 .section-header p {
@@ -708,13 +762,73 @@ body {
 /* =======================
    Responsive
    ======================= */
+@media (max-width: 1024px) {
+  .hero-container {
+    gap: 3rem;
+  }
+}
+
 @media (max-width: 768px) {
   .nav-container {
     padding: 0 1rem;
   }
 
+  /* Show hamburger, convert links to dropdown */
+  .nav-toggle {
+    display: inline-flex;
+  }
+
   .nav-links {
+    position: absolute;
+    top: 64px; /* below navbar */
+    left: 16px;
+    right: 16px;
+    display: none; /* hidden until opened */
+    flex-direction: column;
+    gap: 0;
+    list-style: none;
+    background: #ffffff;
+    border: 1px solid rgba(2, 6, 23, 0.08);
+    border-radius: 12px;
+    box-shadow: var(--shadow);
+    padding: 8px;
+    z-index: 1001;
+  }
+
+  .nav-links.open {
+    display: flex;
+  }
+
+  .nav-links li {
+    width: 100%;
+  }
+
+  .nav-links a {
+    display: block;
+    width: 100%;
+    padding: 12px 14px;
+    border-radius: 8px;
+  }
+
+  .nav-links a:hover {
+    background: #f8fafc;
+  }
+
+  /* Remove desktop underline animation on mobile */
+  .nav-links a::after {
     display: none;
+    content: none;
+  }
+
+  /* Animate hamburger to X when active */
+  .nav-toggle.active .bar:nth-child(1) {
+    transform: translateY(7px) rotate(45deg);
+  }
+  .nav-toggle.active .bar:nth-child(2) {
+    opacity: 0;
+  }
+  .nav-toggle.active .bar:nth-child(3) {
+    transform: translateY(-7px) rotate(-45deg);
   }
 
   .hero-container {
@@ -793,7 +907,9 @@ body {
   font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif !important;
 }
 
-/* Article layout for newsletter detail */
+/* =======================
+   Article layout for newsletter detail
+   ======================= */
 .article-wrap {
   max-width: 1200px;
   margin: 6rem auto 3rem;
@@ -872,8 +988,13 @@ body {
   color: var(--text-dark);
   font-size: 0.95rem;
 }
-#toc-list a:hover { color: var(--secondary); }
-.toc-h3 { margin-left: 0.75rem; opacity: 0.9; }
+#toc-list a:hover {
+  color: var(--secondary);
+}
+.toc-h3 {
+  margin-left: 0.75rem;
+  opacity: 0.9;
+}
 
 .article-main .article-hero {
   display: flex;