Photo: Tweak reveal animations and fix horizontal scroll

- Photo number doesn't jumps anymore (now reveals based on photo not the number)
- Properly reveal title locations lines
- Optimize code

src/style/molecules/_photo.scss

@@ -15,13 +15,18 @@
 
         h2 {
             text-align: left;
-            overflow: hidden;
 
             @include breakpoint (xs) {
                 font-size: rem(40px);
             }
+        }
+        .line {
+            overflow: hidden;
+            padding-bottom: 3px;
+            display: block;
 
             span {
+                position: relative;
                 display: block;
                 will-change: transform;
             }
@@ -29,6 +34,7 @@
         p {
             color: $color-lightgray;
             margin-top: 16px;
+            will-change: opacity;
         }
     }
 
@@ -143,6 +149,7 @@
         user-select: none;
 
         span {
+            position: relative;
             display: block;
             will-change: transform;
         }