Migrate CSS files to subdirectory

assets/css/global.css

@@ -0,0 +1,52 @@
+@import url('https://fonts.googleapis.com/css2?family=Inter:ital,opsz,wght@0,14..32,100..900;1,14..32,100..900&display=swap');
+@import url('navigation.css');
+
+body {
+    background-color: white;
+    font-family: 'Inter', sans-serif;
+    color: black;
+
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    margin: 16px;
+}
+
+header {
+    display: flex;
+    max-width: 720px;
+    width: 100%;
+    position: relative;
+    z-index: 1001;
+}
+
+
+main {
+    max-width: 720px;
+    width: 100%;
+}
+
+footer {
+    max-width: 720px;
+    width: 100%;
+
+    padding-bottom: 64px;
+    padding-top: 64px;
+    color: dimgray;
+}
+
+a {
+    color: unset;
+}
+
+
+
+@media screen and (min-width: 720px) {
+    main {
+        padding-top: 32px;
+    }
+}
+
+img {
+    max-width: 100%;
+}