Update base.css

Author: Eonasdan

docs/theme/css/base.css

@@ -314,3 +314,103 @@ h1:hover .headerlink, h2:hover .headerlink, h3:hover .headerlink, h4:hover .head
     -moz-border-radius: 6px 0 6px 6px;
     border-radius: 6px 0 6px 6px;
 }
+
+#carbonads {
+  --width: 180px;
+  --font-size: 14px;
+}
+
+#carbonads {
+  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen-Sans, Ubuntu, Cantarell, "Helvetica Neue", Helvetica, Arial, sans-serif;
+  display: block;
+  overflow: hidden;
+  margin-bottom: 20px;
+  max-width: var(--width);
+  border-radius: 4px;
+  text-align: center;
+  box-shadow: 0 0 0 1px hsla(0, 0%, 0%, .1);
+  background-color: hsl(0, 0%, 98%);
+  font-size: var(--font-size);
+  line-height: 1.5;
+}
+
+#carbonads a {
+  color: inherit;
+  text-decoration: none;
+}
+
+#carbonads a:hover {
+  color: inherit;
+}
+
+#carbonads span {
+  position: relative;
+  display: block;
+  overflow: hidden;
+}
+
+.carbon-img {
+  display: block;
+  margin-bottom: 8px;
+  max-width: var(--width);
+  line-height: 1;
+}
+
+.carbon-img img {
+  display: block;
+  margin: 0 auto;
+  max-width: var(--width) !important;
+  width: var(--width);
+  height: auto;
+}
+
+.carbon-text {
+  display: block;
+  padding: 0 1em 8px;
+}
+
+.carbon-poweredby {
+  display: block;
+  padding: 10px var(--font-size);
+  background: repeating-linear-gradient(-45deg, transparent, transparent 5px, hsla(0, 0%, 0%, .025) 5px, hsla(0, 0%, 0%, .025) 10px) hsla(203, 11%, 95%, .4);
+  text-transform: uppercase;
+  letter-spacing: .5px;
+  font-weight: 600;
+  font-size: 9px;
+  line-height: 0;
+}
+
+@media only screen and (min-width: 320px) and (max-width: 759px) {
+  #carbonads {
+    float: none;
+    margin: 0 auto;
+    max-width: 330px;
+  }
+  #carbonads span {
+    position: relative;
+  }
+  #carbonads > span {
+    max-width: none;
+  }
+  .carbon-img {
+    float: left;
+    margin: 0;
+  }
+
+  .carbon-img img {
+    max-width: 130px !important;
+  }
+  .carbon-text {
+    float: left;
+    margin-bottom: 0;
+    padding: 8px 20px;
+    text-align: left;
+    max-width: calc(100% - 130px - 3em);
+  }
+  .carbon-poweredby {
+    left: 130px;
+    bottom: 0;
+    display: block;
+    width: 100%;
+  }
+}