chore: improve html archi + header styles

app/components/AppHeader.vue

@@ -1,68 +1,92 @@
 <script setup lang="ts">
 const appConfig = useAppConfig()
-const { isScrolled } = useScroll(100)
+
+const scrollThreshold = ref<number>(0)
+
+onMounted(() => {
+  const updateThreshold = () => {
+    const viewportHeight = window.innerHeight || document.documentElement.clientHeight;
+    
+    scrollThreshold.value = Math.round(viewportHeight * 0.68);
+  }
+
+  updateThreshold()
+})
+
+const effectiveScrollThreshold = computed(() => {
+  return import.meta.client ? scrollThreshold.value : 0;
+});
+
+const { isScrolled } = useScroll(effectiveScrollThreshold.value)
 </script>
 
 <template>
-  <header
-    class="app-header"
-    :class="{ 'is-fixed': isScrolled }"
-  >
-    <img
-      v-if="isScrolled"
-      src="~/assets/images/brand-desktop.svg"
-      :alt="appConfig.title"
-    />
-
-    <template v-if="!isScrolled">
-      <img class="brand-logo" src="~/assets/images/brand-logo.svg" :alt="`${appConfig.title} - Logo`" />
-      <img src="~/assets/images/brand-mobile.svg" :alt="appConfig.title" />
-      <p>{{ appConfig.description }}</p>
-    </template>
-
-    <NuxtLink v-if="isScrolled" to="#about">⭣ About</NuxtLink>
+  <header class="app-header">
+    <img class="brand-logo" src="~/assets/images/brand-logo.svg" :alt="`${appConfig.title} - Logo`" />
+    <img class="brand" src="~/assets/images/brand-mobile.svg" :alt="appConfig.title" />
+    <p>{{ appConfig.description }}</p>
+  </header>
+  <header class="app-header--sticky" v-if="isScrolled">
+    <img src="~/assets/images/brand-desktop.svg" :alt="appConfig.title" />
+    <NuxtLink to="#about">⭣ About</NuxtLink>
   </header>
-
 </template>
 
 <style lang="css" scoped>
-.app-header {
+@keyframes slideDown {
+  from {
+    transform: translateY(-100%);
+  }
+  to {
+    transform: translateY(0);
+  }
+}
+
+.app-header,
+.app-header--sticky {
+  display: flex;
   background-color: var(--primary-color);
   color: var(--secondary-color);
-  display: flex;
-  gap: 1rem;
-  transition: all 0.3s ease;
-  height: 68vh;
-  padding: 3rem 2rem;
-  flex-direction: column;
 }
 
-.app-header.is-fixed {
-  box-sizing: border-box;
+.app-header {
+  gap: 1rem;
+  flex-direction: column;
+  padding: 3rem 2rem;
+  height: 68vh;
+}
+
+.app-header--sticky {
   position: fixed;
   top: 0;
-  left: 0;
-  right: 0;
+  width: 100%;
   height: 34px;
   padding: 0.75rem 2rem;
-  flex-direction: row;
-  z-index: 10;
   align-items: center;
+  animation: slideDown 0.3s ease;
+  z-index: 10;
+  box-sizing: border-box;
+  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.08), 0 1px 2px rgba(0, 0, 0, 0.06);
 }
 
-.app-header.is-fixed img {
+.app-header--sticky img {
   height: 11px;
 }
 
 .brand-logo {
   align-self: flex-end;
   margin-bottom: auto;
-  width: 36vw;
+  width: 135px;
+}
+
+.brand {
+  width: 300px;
 }
 
 a {
   margin-left: auto;
   font-weight: 500;
+  color: inherit;
 }
 
 p {