Update styles

src/components/SiteHeader.vue

@@ -0,0 +1,66 @@
+<template>
+  <header id="header">
+    <router-link to="/">
+      <img id="nav-logo" alt="KamilCraft.com logo" :src="`${publicPath}assets/logo.png`">
+    </router-link>
+    <nav id="navigation">
+      <ul id="menu">
+        <li class="menu-element"><router-link to="/">Strona główna</router-link></li>
+        <li class="menu-element"><router-link to="/projects">Projekty</router-link></li>
+        <li class="menu-element"><router-link to="/about">O mnie</router-link></li>
+        <li class="menu-element"><router-link to="/contact">Kontakt</router-link></li>
+      </ul>
+    </nav>
+  </header>
+</template>
+
+<style lang="scss">
+#header {
+  width: 250px;
+  height: 100vh;
+  background-color: #4f4f4f !important;
+  #nav-logo {
+    display: block;
+    width: 250px;
+    padding: 8px 0;
+    background-color: #fafafa !important;
+  }
+  #navigation {
+    #menu {
+      list-style: none;
+      margin: 0;
+      .menu-element {
+        display: block;
+        padding: 0 10px;
+
+        &:hover {
+          background: rgba(0, 0 , 0, .1);
+        }
+      }
+
+      a {
+        display: block;
+        line-height: 50px;
+        font-weight: bold;
+        color: #dcdcdc;
+
+        &.router-link-exact-active {
+          color: white;
+        }
+      }
+
+    }
+  }
+}
+</style>
+
+<script>
+export default {
+  name: 'SiteHeader',
+  data () {
+    return {
+      publicPath: process.env.BASE_URL
+    }
+  }
+}
+</script>