diff --git a/part-1/1-parent-child/index.html b/part-1/1-parent-child/index.html
index e271a9b..d1a41a4 100644
--- a/part-1/1-parent-child/index.html
+++ b/part-1/1-parent-child/index.html
@@ -27,6 +27,7 @@
           <p class="message__content">
             I can meet on Tuesday and Wednesday after 4.
           </p>
+          <span class="message__time">7:15pm</span>
         </div>
       </div>
     </div>
diff --git a/part-1/2-html-attributes/index.html b/part-1/2-html-attributes/index.html
index eff2de0..9557aae 100644
--- a/part-1/2-html-attributes/index.html
+++ b/part-1/2-html-attributes/index.html
@@ -23,14 +23,20 @@
         <div class="message">
           <div class="message__author">Luke</div>
           <p class="message__content">
-            Let's meet at the iCafe in Merchant City. https://goo.gl/maps/aza4h9nUBhn
+            Let's meet at the <a href="https://goo.gl/maps/aza4h9nUBhn"> iCafe</a> in Merchant City.
           </p>
           <span class="message__time">7:35pm</span>
         </div>
         <div class="message">
           <div class="message__author">Won</div>
           <p class="message__content">
-            Ok! https://media.giphy.com/media/l41K4KlVE8dgozf8I/giphy.gif
+            Ok!
+            <img
+              src="//media.giphy.com/media/l41K4KlVE8dgozf8I/giphy.gif"
+              alt="see you soon!"
+              height="170px"
+              width="400px"
+            />
           </p>
           <span class="message__time">7:38pm</span>
         </div>
diff --git a/part-1/3-semantic-html/index.html b/part-1/3-semantic-html/index.html
index eea1670..6129f2e 100644
--- a/part-1/3-semantic-html/index.html
+++ b/part-1/3-semantic-html/index.html
@@ -12,32 +12,40 @@
 
   <body>
     <div class="site-wrapper">
-      <div class="site-header">
+      <header role="banner" class="site-header">
         <div class="site-header__title">Messages</div>
-      </div>
-      <div class="messages">
-        <div class="message">
+      </header>
+      <main role="main" class="messages">
+        <article class="message">
           <div class="message__author">Won</div>
           <p class="message__content">Where should we meet later?</p>
-          <span class="message__time">Mar 25, 2018 7:25pm</span>
-        </div>
-        <div class="message">
+          <time class="message__time" datetime="2018-3-25T19:25:00">Mar 25, 2018 7:25pm</time>
+        </article>
+
+        <article class="message">
           <div class="message__author">Luke</div>
           <p class="message__content">
-            Let's meet at the iCafe in Merchant City. https://goo.gl/maps/aza4h9nUBhn
+            Let's meet at the<a href=" https://goo.gl/maps/aza4h9nUBhn">iCafe </a>in Merchant City.
           </p>
-          <span class="message__time">Mar 25, 2018 7:35pm</span>
-        </div>
-        <div class="message">
+          <time class="message__time" datetime="2018-3-25T19:35:00">Mar 25, 2018 7:35pm</time>
+        </article>
+        <article class="message">
           <div class="message__author">Won</div>
           <p class="message__content">
-            Ok! https://media.giphy.com/media/l41K4KlVE8dgozf8I/giphy.gif
+            Ok!
+            <img
+              src="//media.giphy.com/media/l41K4KlVE8dgozf8I/giphy.gif"
+              alt="see you soon!"
+              height="170px"
+              width="400px"
+            />
           </p>
-          <span class="message__time">Mar 25, 2018 7:38pm</span>
-        </div>
-      </div>
+          <time class="message__time" datetime="2018-3-25T19:38:00">Mar 25, 2018 7:38pm</time>
+        </article>
+      </main>
       <div id="result" class="result"></div>
     </div>
+
     <script defer src="/js/3-result.js"></script>
   </body>
 </html>
diff --git a/part-1/4-links-scripts/index.html b/part-1/4-links-scripts/index.html
index 303c7fb..682025e 100644
--- a/part-1/4-links-scripts/index.html
+++ b/part-1/4-links-scripts/index.html
@@ -4,6 +4,7 @@
     <meta charset="utf-8" />
     <title>4. Adding Links and Scripts - HTML, CSS and Git Exercises</title>
     <meta name="viewport" content="width=device-width, initial-scale=1" />
+    <link rel="stylesheet" href="css/missing-styles.css" />
   </head>
 
   <body>
@@ -33,5 +34,6 @@
         </div>
       </div>
     </div>
+    <script src="convertUrls.js"></script>
   </body>
 </html>
diff --git a/part-1/5-css-selectors/message-backgrounds.css b/part-1/5-css-selectors/message-backgrounds.css
index ffe4833..ab04c75 100644
--- a/part-1/5-css-selectors/message-backgrounds.css
+++ b/part-1/5-css-selectors/message-backgrounds.css
@@ -1 +1,12 @@
 /* Add your CSS code below */
+#first-message {
+  background-color: red;
+}
+
+article {
+  background-color: cadetblue;
+}
+
+.message--latest {
+  background-color: yellow;
+}
diff --git a/part-1/6-css-properties/styles.css b/part-1/6-css-properties/styles.css
index ffe4833..9b6f1b3 100644
--- a/part-1/6-css-properties/styles.css
+++ b/part-1/6-css-properties/styles.css
@@ -1 +1,23 @@
 /* Add your CSS code below */
+
+a {
+  color: red;
+  font-weight: bold;
+  text-decoration: none;
+}
+
+.message__time {
+  font-size: 0.9rem;
+}
+
+.message--unread {
+  border-left: 1.5px solid blue;
+}
+
+.message__time--old {
+  opacity: 0.45;
+}
+
+.message {
+  line-height: 2.8;
+}
diff --git a/part-1/7-css-box/styles.css b/part-1/7-css-box/styles.css
index 013b94f..67d04bd 100644
--- a/part-1/7-css-box/styles.css
+++ b/part-1/7-css-box/styles.css
@@ -4,3 +4,8 @@
   border-radius: 4px;
   background: #fff;
 }
+
+.country {
+  margin: 15px;
+  border: 3px solid white;
+}
diff --git a/part-1/8-advanced-selectors/styles.css b/part-1/8-advanced-selectors/styles.css
index d35c3c3..60148a9 100644
--- a/part-1/8-advanced-selectors/styles.css
+++ b/part-1/8-advanced-selectors/styles.css
@@ -1 +1,15 @@
 /* Try different box model properties below */
+
+.site-header p {
+  color: white;
+  margin-bottom: 0%;
+}
+
+.site-footer {
+  font-size: 12px;
+  text-align: center;
+}
+
+.message:last-child {
+  box-shadow: 4px 4px 0 #dba944;
+}
diff --git a/part-2/10-media-queries/columns.css b/part-2/10-media-queries/columns.css
index 43e80d2..261753b 100644
--- a/part-2/10-media-queries/columns.css
+++ b/part-2/10-media-queries/columns.css
@@ -1 +1,13 @@
 /* Add your own CSS code below */
+
+@media (min-width: 768px) {
+  .countries {
+    columns: 2;
+  }
+}
+
+@media (min-width: 1200px) {
+  .countries {
+    columns: 3;
+  }
+}
diff --git a/part-2/11-flexbox/flexbox.css b/part-2/11-flexbox/flexbox.css
index 43e80d2..9b2039c 100644
--- a/part-2/11-flexbox/flexbox.css
+++ b/part-2/11-flexbox/flexbox.css
@@ -1 +1,17 @@
 /* Add your own CSS code below */
+
+.countries {
+  display: flex;
+}
+
+.countries--first {
+  flex-direction: row-reverse;
+}
+
+.countries--second {
+  flex-direction: column;
+}
+
+.countries--second {
+  flex-direction: column-reverse;
+}
diff --git a/part-2/12-justify-content/flexbox.css b/part-2/12-justify-content/flexbox.css
index 3c4c7ff..730c89d 100644
--- a/part-2/12-justify-content/flexbox.css
+++ b/part-2/12-justify-content/flexbox.css
@@ -7,3 +7,18 @@
 }
 
 /* Add your own CSS code below */
+
+.countries--first {
+  justify-content: end;
+}
+.countries--second {
+  justify-content: space-around;
+}
+.countries--third {
+  flex-direction: column;
+  justify-content: end;
+}
+.countries--fourth {
+  flex-direction: column-reverse;
+  justify-content: space-around;
+}
diff --git a/part-2/13-align-items/flexbox.css b/part-2/13-align-items/flexbox.css
index 3675a0d..38e2f1b 100644
--- a/part-2/13-align-items/flexbox.css
+++ b/part-2/13-align-items/flexbox.css
@@ -2,3 +2,23 @@
   display: flex;
 }
 /* Add your own CSS code below */
+
+.countries--first {
+  align-items: center;
+  flex-direction: row;
+}
+
+.countries--second {
+  align-items: flex-end;
+  flex-direction: row-reverse;
+}
+
+.countries--third {
+  flex-direction: column;
+  align-items: flex-end;
+}
+
+.countries--fourth {
+  align-items: center;
+  flex-direction: column-reverse;
+}
diff --git a/part-2/14-order/flexbox.css b/part-2/14-order/flexbox.css
index ed621b7..34107e8 100644
--- a/part-2/14-order/flexbox.css
+++ b/part-2/14-order/flexbox.css
@@ -3,3 +3,40 @@
 }
 
 /* Add your own CSS code below */
+
+.countries--first > .country--brazil {
+  order: 5;
+}
+
+.countries--second > .country--brazil {
+  order: 4;
+}
+
+.countries--second > .country--croatia {
+  order: 1;
+}
+.countries--second > .country--ethiopia {
+  order: 2;
+}
+.countries--second > .country--laos {
+  order: 3;
+}
+
+.countries--second > .country--uganda {
+  order: 5;
+}
+.countries--third > .country--brazil {
+  order: 5;
+}
+.countries--third > .country--croatia {
+  order: 4;
+}
+.countries--third > .country--ethiopia {
+  order: 3;
+}
+.countries--third > .country--laos {
+  order: 2;
+}
+.countries--third > .country--uganda {
+  order: 1;
+}
diff --git a/part-2/15-align-self/flexbox.css b/part-2/15-align-self/flexbox.css
index ed621b7..4898f32 100644
--- a/part-2/15-align-self/flexbox.css
+++ b/part-2/15-align-self/flexbox.css
@@ -3,3 +3,34 @@
 }
 
 /* Add your own CSS code below */
+
+.countries--first > .country--ethiopia {
+  align-self: end;
+}
+
+.countries--second > .country--ethiopia {
+  align-self: end;
+}
+.countries--second {
+  align-items: center;
+}
+
+.countries--third > .country--brazil {
+  align-self: flex-start;
+}
+
+.countries--third > .country--uganda {
+  align-self: flex-start;
+}
+.countries--third {
+  align-items: flex-end;
+}
+
+.countries--fourth {
+  align-items: flex-start;
+  flex-direction: column;
+}
+
+.countries--fourth > .country--uganda {
+  align-self: center;
+}
diff --git a/part-2/16-more-flexbox/flexbox.css b/part-2/16-more-flexbox/flexbox.css
index ed621b7..465c9dc 100644
--- a/part-2/16-more-flexbox/flexbox.css
+++ b/part-2/16-more-flexbox/flexbox.css
@@ -3,3 +3,51 @@
 }
 
 /* Add your own CSS code below */
+
+.countries--first {
+  align-items: flex-end;
+  justify-content: flex-end;
+}
+
+.countries--second {
+  align-items: flex-end;
+  justify-content: center;
+  flex-direction: row-reverse;
+}
+
+.countries--third {
+  align-items: flex-start;
+  justify-content: center;
+}
+.countries--third > .country--brazil {
+  align-self: flex-end;
+}
+
+.countries--fourth {
+  align-items: flex-end;
+  flex-direction: column;
+  justify-content: center;
+}
+
+.countries--fourth > .country--ethiopia {
+  align-self: center;
+}
+
+.countries--fourth > .country--laos {
+  align-self: center;
+}
+
+.countries--fifth {
+  align-items: flex-end;
+  flex-direction: column-reverse;
+  justify-content: space-between;
+}
+
+.countries--fifth > .country--laos {
+  order: 2;
+}
+
+.countries--fifth > .country--uganda {
+  order: 1;
+  align-self: center;
+}
diff --git a/part-2/17-nav-menu/styles.css b/part-2/17-nav-menu/styles.css
index f04f4c7..5290589 100644
--- a/part-2/17-nav-menu/styles.css
+++ b/part-2/17-nav-menu/styles.css
@@ -1 +1,22 @@
 /* Write your media queries and flexbox CSS below */
+
+@media (min-width: 480px) {
+  .site-header__nav {
+    display: flex;
+    flex-direction: row;
+  }
+}
+@media (min-width: 700px) {
+  .site-header {
+    display: flex;
+    flex-direction: row;
+  }
+}
+@media (min-width: 992px) {
+  .site-header {
+    display: flex;
+    flex-direction: row;
+    justify-content: space-between;
+    align-items: end;
+  }
+}
diff --git a/part-2/18-git-merge/styles.css b/part-2/18-git-merge/styles.css
index 0051cdb..af46a4f 100644
--- a/part-2/18-git-merge/styles.css
+++ b/part-2/18-git-merge/styles.css
@@ -1,6 +1,6 @@
 /* Add your own CSS code below */
 .link {
-  color: #4491db;
+  color: orangered;
   font-weight: 700;
   text-decoration: none;
 }
