Add basic page styles

css/style.css

@@ -0,0 +1,16 @@
+body {
+    font-family: Arial, sans-serif;
+    margin: 40px;
+}
+
+h1 {
+    font-size: 32px;
+}
+
+p {
+    font-size: 18px;
+}
+
+li {
+    margin-bottom: 8px;
+}

index.html

@@ -1,6 +1,7 @@
 <!DOCTYPE html>
 <html lang="ru">
 <head>
+    <link rel="stylesheet" href="css/style.css">
     <meta charset="UTF-8">
     <title>Интернет-магазин</title>
 </head>