diff --git a/package-lock.json b/package-lock.json
index 62799b8..344ef02 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -3355,7 +3355,8 @@
         "ansi-regex": {
           "version": "2.1.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "aproba": {
           "version": "1.2.0",
@@ -3376,12 +3377,14 @@
         "balanced-match": {
           "version": "1.0.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "brace-expansion": {
           "version": "1.1.11",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "balanced-match": "^1.0.0",
             "concat-map": "0.0.1"
@@ -3396,17 +3399,20 @@
         "code-point-at": {
           "version": "1.1.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "concat-map": {
           "version": "0.0.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "console-control-strings": {
           "version": "1.1.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "core-util-is": {
           "version": "1.0.2",
@@ -3523,7 +3529,8 @@
         "inherits": {
           "version": "2.0.3",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "ini": {
           "version": "1.3.5",
@@ -3535,6 +3542,7 @@
           "version": "1.0.0",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "number-is-nan": "^1.0.0"
           }
@@ -3549,6 +3557,7 @@
           "version": "3.0.4",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "brace-expansion": "^1.1.7"
           }
@@ -3556,12 +3565,14 @@
         "minimist": {
           "version": "0.0.8",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "minipass": {
           "version": "2.3.5",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "safe-buffer": "^5.1.2",
             "yallist": "^3.0.0"
@@ -3580,6 +3591,7 @@
           "version": "0.5.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "minimist": "0.0.8"
           }
@@ -3660,7 +3672,8 @@
         "number-is-nan": {
           "version": "1.0.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "object-assign": {
           "version": "4.1.1",
@@ -3672,6 +3685,7 @@
           "version": "1.4.0",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "wrappy": "1"
           }
@@ -3757,7 +3771,8 @@
         "safe-buffer": {
           "version": "5.1.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "safer-buffer": {
           "version": "2.1.2",
@@ -3793,6 +3808,7 @@
           "version": "1.0.2",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "code-point-at": "^1.0.0",
             "is-fullwidth-code-point": "^1.0.0",
@@ -3812,6 +3828,7 @@
           "version": "3.0.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "ansi-regex": "^2.0.0"
           }
@@ -3855,12 +3872,14 @@
         "wrappy": {
           "version": "1.0.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "yallist": {
           "version": "3.0.3",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         }
       }
     },
diff --git a/step1-00/css-demo.css b/step1-00/css-demo.css
index 62b4a88..d8f4ffb 100644
--- a/step1-00/css-demo.css
+++ b/step1-00/css-demo.css
@@ -1,29 +1,31 @@
+/* https://developer.mozilla.org/en-US/docs/Learn/CSS/Introduction_to_CSS/Combinators_and_multiple_selectors */
+
+/* Targeting an HTML tag */
 h1 {
-  padding: 10px;
-  margin-bottom: 15px;
-  margin-top: 15px;
   color: black;
   background: #ddd;
   border: 1px solid #ababab;
+  margin-bottom: 15px;
+  margin-top: 15px;
+  padding: 10px;
 }
 
-a {
-  color: white;
-}
-a:hover {
-  color: #ccc;
+/* Overriding inherited styles */
+span {
+  color: #004578;
 }
 
+/* Targeting a class name  */
 .tiles {
   display: flex;
 }
 
+/* Decendant selector */
 .tiles img {
-  display: block;
-  margin: 0 auto;
-  max-width: 75%;
+  width: 100%;
 }
 
+/* Direct decendant selector */
 .tiles > div {
   background: rgb(10, 10, 10);
   color: white;
@@ -32,18 +34,38 @@ a:hover {
   margin-right: 20px;
 }
 
+/* Qualified selector */
+div.links {
+  background: #004578;
+}
+
+/* Style inheritance only works for unstyled elements */
+a {
+  color: white;
+}
+
+/* Pseudo hover selector */
+a:hover {
+  color: #ccc;
+}
+
+/* Sibling selectors */
+a ~ a {
+  display: block;
+}
+
+/* Positional Pseudo Selectors  */
 .tiles > div:last-child {
   margin-right: 0;
 }
 
-a + a {
-  display: block;
-}
-
-#contact-form > * {
+/* ID and selector lists */
+#contact-form label,
+#contact-form input {
   display: block;
 }
 
+/* Attribute selector */
 input[type='submit'] {
   margin-top: 10px;
 }
diff --git a/step1-00/css-demo.html b/step1-00/css-demo.html
index 99ecc74..6aed91a 100644
--- a/step1-00/css-demo.html
+++ b/step1-00/css-demo.html
@@ -6,7 +6,7 @@
     <div>
       <h1>This is my <span>Title</span></h1>
       <div class="tiles">
-        <div>
+        <div class="links">
           <h2>Important Links</h2>
           <a href="#">We're Awesome</a>
           <a href="#">Learn More</a>
@@ -14,14 +14,14 @@
         </div>
         <div>
           <h2>Our Logo</h2>
-          <img src="./fabric.jpg" alt="fabric logo" />
+          <img src="./fabric.jpg" width="100" alt="fabric logo" />
         </div>
         <div>
           <h2>Contact Us</h2>
-          <form id="contact-form">
+          <div id="contact-form">
             <label>Email</label><input type="email" />
             <input value="Submit" type="submit" />
-          </form>
+          </div>
         </div>
       </div>
     </div>