feat: harden portfolio and add SEO foundations

app/globals.css

@@ -63,6 +63,10 @@
     margin: 0;
     padding: 0;
   }
+
+  a {
+    color: inherit;
+  }
 }
 
 html,
@@ -94,9 +98,9 @@ html [id] {
 }
 
 .site-header-menu-toggle {
-  width: 32px;
-  height: 32px;
-  flex: 0 0 32px;
+  width: 44px;
+  height: 44px;
+  flex: 0 0 44px;
 }
 
 @media (min-width: 1025px) {
@@ -144,6 +148,26 @@ html [id] {
   outline-offset: 3px;
 }
 
+.film-grain {
+  position: fixed;
+  inset: 0;
+  z-index: 9990;
+  pointer-events: none;
+  background:
+    repeating-radial-gradient(
+      circle at 20% 30%,
+      var(--paper) 0 0.6px,
+      transparent 0.8px 3px
+    ),
+    repeating-radial-gradient(
+      circle at 70% 60%,
+      var(--ink) 0 0.5px,
+      transparent 0.7px 4px
+    );
+  mix-blend-mode: overlay;
+  opacity: 0.08;
+}
+
 @media (prefers-reduced-motion: reduce), (pointer: coarse) {
   .film-grain {
     display: none;
@@ -173,10 +197,6 @@ svg {
   }
 }
 
-a {
-  color: inherit;
-}
-
 button,
 input,
 select,
@@ -506,23 +526,63 @@ textarea {
 }
 
 @keyframes marquee {
-  0% {
+  from {
     transform: translateX(0);
   }
-  100% {
+
+  to {
     transform: translateX(-50%);
   }
 }
 
 @keyframes marquee-reverse {
-  0% {
+  from {
     transform: translateX(-50%);
   }
-  100% {
+
+  to {
     transform: translateX(0);
   }
 }
 
+.scroll-velocity-text {
+  position: relative;
+  color: inherit;
+}
+
+.scroll-velocity-viewport {
+  overflow: hidden;
+  white-space: nowrap;
+}
+
+.scroll-velocity-track,
+.scroll-velocity-group {
+  display: flex;
+  width: max-content;
+}
+
+.scroll-velocity-group {
+  flex-shrink: 0;
+  min-width: 100vw;
+}
+
+.scroll-velocity-item {
+  display: inline-flex;
+  align-items: center;
+  flex-shrink: 0;
+  font-family: var(--font-display);
+  font-size: clamp(3rem, 10vw, 8rem);
+  font-weight: 800;
+  line-height: 1;
+  letter-spacing: -0.04em;
+  text-transform: uppercase;
+}
+
+.scroll-velocity-dot {
+  margin-inline: var(--sp-8);
+  color: var(--slash);
+}
+
 .animate-marquee {
   animation: marquee 40s linear infinite;
 }
@@ -531,6 +591,71 @@ textarea {
   animation: marquee-reverse 45s linear infinite;
 }
 
+.scroll-velocity-text:hover .scroll-velocity-track,
+.scroll-velocity-text:focus-within .scroll-velocity-track {
+  animation-play-state: paused;
+}
+
+.scroll-velocity-control {
+  position: absolute;
+  top: var(--sp-2);
+  right: var(--sp-3);
+  z-index: 1;
+  min-height: 44px;
+  border: 1px solid var(--slash);
+  background: var(--ink);
+  color: var(--paper);
+  padding-inline: var(--sp-3);
+  font-family: var(--font-mono);
+  font-size: 11px;
+  font-weight: 700;
+  letter-spacing: 0.06em;
+  text-transform: uppercase;
+  cursor: pointer;
+}
+
+@media (prefers-reduced-motion: reduce) {
+  .scroll-velocity-text {
+    color: var(--paper);
+  }
+
+  .scroll-velocity-track {
+    animation: none;
+    transform: none;
+  }
+
+  .scroll-velocity-viewport {
+    overflow: visible;
+    white-space: normal;
+  }
+
+  .scroll-velocity-track,
+  .scroll-velocity-group {
+    display: block;
+    width: 100%;
+  }
+
+  .scroll-velocity-group {
+    min-width: 0;
+  }
+
+  .scroll-velocity-group[aria-hidden="true"] {
+    display: none;
+  }
+
+  .scroll-velocity-item {
+    display: block;
+    padding: var(--sp-6);
+    font-size: clamp(2rem, 8vw, 4rem);
+    line-height: 1.1;
+    white-space: normal;
+  }
+
+  .scroll-velocity-dot {
+    display: none;
+  }
+}
+
 .ds-skeleton-card {
   display: flex;
   flex-direction: column;
@@ -783,9 +908,11 @@ textarea {
     transform: translateX(-100%);
     opacity: 0;
   }
+
   50% {
     opacity: 0.8;
   }
+
   100% {
     transform: translateX(100%);
     opacity: 0;
@@ -798,12 +925,106 @@ textarea {
     transform: scale(1);
     opacity: 0.3;
   }
+
   50% {
     transform: scale(2);
     opacity: 1;
   }
 }
 
+.section-divider {
+  pointer-events: none;
+}
+
+.section-divider-gradient {
+  position: relative;
+  width: 100%;
+  height: 1px;
+  overflow: hidden;
+}
+
+.section-divider-gradient span {
+  position: absolute;
+  inset: 0;
+  background: linear-gradient(90deg, transparent, var(--slash), transparent);
+  opacity: 0.3;
+}
+
+.section-divider-gradient span:last-child {
+  animation: shimmerDivider 3s ease-in-out infinite;
+  opacity: 0.6;
+}
+
+.section-divider-pulse {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  gap: var(--sp-2);
+  padding-block: var(--sp-8);
+}
+
+.section-divider-pulse span {
+  width: 4px;
+  height: 4px;
+  border-radius: 50%;
+  background: var(--slash);
+  animation: pulseDot 2s ease-in-out infinite;
+}
+
+.section-divider-pulse span:nth-child(2) {
+  animation-delay: 0.15s;
+}
+
+.section-divider-pulse span:nth-child(3) {
+  animation-delay: 0.3s;
+}
+
+.section-divider-pulse span:nth-child(4) {
+  animation-delay: 0.45s;
+}
+
+.section-divider-pulse span:nth-child(5) {
+  animation-delay: 0.6s;
+}
+
+.section-divider-waveform {
+  width: 100%;
+  height: 60px;
+  color: var(--slash);
+}
+
+.section-divider-waveform svg {
+  display: block;
+  width: 100%;
+  height: 60px;
+}
+
+.section-divider-waveform path {
+  fill: none;
+  stroke: currentColor;
+  stroke-width: 1;
+  vector-effect: non-scaling-stroke;
+}
+
+.section-divider-waveform path:nth-child(1) {
+  opacity: 0.1;
+}
+
+.section-divider-waveform path:nth-child(2) {
+  opacity: 0.07;
+}
+
+.section-divider-waveform path:nth-child(3) {
+  opacity: 0.04;
+}
+
+@media (prefers-reduced-motion: reduce) {
+  .section-divider-gradient span:last-child,
+  .section-divider-pulse span {
+    animation: none;
+  }
+}
+
 /* Cinematic card hover effect */
 .ds-card {
   transition: all 0.5s cubic-bezier(0.16, 1, 0.3, 1);