more header styles

_includes/header.njk

@@ -9,13 +9,17 @@
 
 {% css %}
 header {
+  display: flex;
   position: sticky;
-  backdrop-filter: blur(5px);
-  background-color: #ffffffcc;
   top: 0;
+  min-height: 6.4rem;
   padding: 2rem 0;
+  backdrop-filter: blur(5px);
+  background-color: rgba(255,255,255,.92);
+  box-shadow: 0 3px 15px hsla(0,0%,39.2%,.12);
 }
 .header-container {
+  width: 100%;
   max-width: var(--page-width);
   margin-left: auto;
   margin-right: auto;
@@ -29,5 +33,30 @@ header {
 }
 #mainNav li {
   display: inline;
+  margin-left: 1rem;
+}
+#mainNav a {
+  position: relative;
+  font-size: 16px;
+  font-family: Aileron;
+  font-weight: 500;
+  line-height: 2;
+  text-transform: uppercase;
+  color: var(--color-text);
+  text-decoration: none;
+}
+#mainNav a::after {
+  content: "";
+  position: absolute;
+  background: var(--color-primary);
+  opacity: 0;
+  bottom: -4px;
+  left: 0;
+  right: 0;
+  height: 2px;
+  transition: opacity .3s ease-out;
+}
+#mainNav a:hover::after {
+  opacity: 1;
 }
 {% endcss %}

_layouts/page.njk

@@ -30,6 +30,9 @@ eleventyComputed:
   --color-primary: {{ eseColor }};
   font-size: 17px;
 }
+* {
+  box-sizing: border-box;
+}
 body {
   margin: 0;
   font-family: sans-serif;