add button loading animations

5 files changed, 270 insertions, 3 deletions

diff --git a/demo/index.html b/demo/index.html
index 92ac08b..3767fb8 100644
--- a/demo/index.html
+++ b/demo/index.html
@@ -6,8 +6,7 @@
     <link rel="stylesheet" href="../dist/spectre.css">
     <style>
         .columns .column {
-            background-color: #efefef;
-            border: 1px solid #ddd;
+            border: 1px solid transparent;
         }
     </style>
 </head>
@@ -87,6 +86,31 @@
                 </div>
             </div>
         </section>
+        <section class="layout">
+            <header class="text-center"><h4>buttons</h4></header>
+            <div class="columns">
+                <div class="column">
+                    <button class="btn">default button</button>
+                </div>
+                <div class="column">
+                    <button class="btn btn-primary">primary button</button>
+                </div>
+                <div class="column">
+                    <button class="btn btn-link">link button</button>
+                </div>
+            </div>
+            <div class="columns">
+                <div class="column">
+                    <button class="btn loading">default button</button>
+                </div>
+                <div class="column">
+                    <button class="btn btn-primary loading">primary button</button>
+                </div>
+                <div class="column">
+                    <button class="btn btn-link loading">link button</button>
+                </div>
+            </div>
+        </section>
     </section>
 </body>
 </html>
\ No newline at end of file
diff --git a/dist/spectre.css b/dist/spectre.css
index 6b3a9fe..ae8f22e 100644
--- a/dist/spectre.css
+++ b/dist/spectre.css
@@ -614,6 +614,117 @@ ol ol {
     width: 8.33333333%;
   }
 }
+.btn,
+button {
+  display: inline-block;
+  padding: .7rem 1.5rem;
+  background-color: transparent;
+  border-radius: 3px;
+  color: #5764C6;
+  font-size: 1.4rem;
+  line-height: 1.2;
+  text-align: center;
+  text-decoration: none;
+  vertical-align: middle;
+  border: 1px solid #5764C6;
+  white-space: nowrap;
+  cursor: pointer;
+  -webkit-user-select: none;
+     -moz-user-select: none;
+      -ms-user-select: none;
+          user-select: none;
+  -webkit-appearance: none;
+  outline: 0;
+}
+.btn:hover,
+button:hover,
+.btn:focus,
+button:focus {
+  color: #fff;
+  background-color: #5764C6;
+}
+.btn:active,
+button:active,
+.btn.active,
+button.active {
+  color: #fff;
+  background-color: #4452c0;
+}
+.btn.loading,
+button.loading {
+  color: transparent !important;
+  pointer-events: none;
+  position: relative;
+}
+.btn.loading::after,
+button.loading::after {
+  border: 2px solid #5764C6;
+  border-right-color: transparent;
+  border-top-color: transparent;
+  border-radius: 8px;
+  content: "";
+  position: absolute;
+  left: 50%;
+  top: 50%;
+  margin-left: -8px;
+  margin-top: -8px;
+  display: block;
+  width: 16px;
+  height: 16px;
+  -webkit-animation: loading 500ms infinite linear;
+          animation: loading 500ms infinite linear;
+}
+.btn[disabled],
+button[disabled] {
+  opacity: .5;
+  cursor: default;
+}
+.btn.btn-primary,
+button.btn-primary {
+  color: #fff;
+  border-color: #5764C6;
+  background-color: #5764C6;
+}
+.btn.btn-primary:hover,
+button.btn-primary:hover,
+.btn.btn-primary:focus,
+button.btn-primary:focus {
+  color: #fff;
+  border-color: #4452c0;
+  background-color: #4452c0;
+}
+.btn.btn-primary:active,
+button.btn-primary:active,
+.btn.btn-primary.active,
+button.btn-primary.active {
+  color: #fff;
+  border-color: #3b49af;
+  background-color: #3b49af;
+}
+.btn.btn-primary.loading::after,
+button.btn-primary.loading::after {
+  border-color: #fff;
+  border-right-color: transparent;
+  border-top-color: transparent;
+}
+.btn.btn-link,
+button.btn-link {
+  color: #5764C6;
+  border-color: transparent;
+  background-color: transparent;
+}
+.btn.btn-link:hover,
+button.btn-link:hover,
+.btn.btn-link:focus,
+button.btn-link:focus {
+  color: #35419c;
+}
+.btn.btn-link:active,
+button.btn-link:active,
+.btn.btn-link.active,
+button.btn-link.active {
+  color: #283176;
+}
 .clearfix::after,
 .container::after,
 .columns::after {
@@ -712,3 +823,23 @@ ol ol {
 .circle {
   border-radius: 50%;
 }
+@-webkit-keyframes loading {
+  0% {
+    -webkit-transform: rotate(0deg);
+            transform: rotate(0deg);
+  }
+  100% {
+    -webkit-transform: rotate(360deg);
+            transform: rotate(360deg);
+  }
+}
+@keyframes loading {
+  0% {
+    -webkit-transform: rotate(0deg);
+            transform: rotate(0deg);
+  }
+  100% {
+    -webkit-transform: rotate(360deg);
+            transform: rotate(360deg);
+  }
+}
diff --git a/src/buttons.less b/src/buttons.less
index 237eaa8..ae5b7d7 100644
--- a/src/buttons.less
+++ b/src/buttons.less
@@ -1 +1,103 @@
-// Buttons
\ No newline at end of file
+// Buttons
+.btn,
+button {
+  display: inline-block;
+  padding: .7rem 1.5rem;
+  background-color: transparent;
+  border-radius: 3px;
+  color: @core-color;
+  font-size: 1.4rem;
+  line-height: 1.2;
+  text-align: center;
+  text-decoration: none;
+  vertical-align: middle;
+  border: 1px solid @core-color;
+  white-space: nowrap;
+  cursor: pointer;
+  user-select: none;
+  -webkit-appearance: none;
+  outline: 0;
+
+  &:hover,
+  &:focus {
+    color: #fff;
+    background-color: @core-color;
+  }
+  &:active,
+  &.active {
+    color: #fff;
+    background-color: darken(@core-color, 5%);
+  }
+
+  &.loading {
+    color: transparent !important;
+    pointer-events: none;
+    position: relative;
+
+    &::after {
+      border: 2px solid @core-color;
+      border-right-color: transparent;
+      border-top-color: transparent;
+      border-radius: 8px;
+      content: "";
+      position: absolute;
+      left: 50%;
+      top: 50%;
+      margin-left: -8px;
+      margin-top: -8px;
+      display: block;
+      width: 16px;
+      height: 16px;
+      animation: loading 500ms infinite linear;
+    }
+  }
+
+  &[disabled] {
+    opacity: .5;
+    cursor: default;
+  }
+
+  &.btn-primary {
+    color: #fff;
+    border-color: @core-color;
+    background-color: @core-color;
+
+    &:hover,
+    &:focus {
+      color: #fff;
+      border-color: darken(@core-color, 5%);
+      background-color: darken(@core-color, 5%);
+    }
+    &:active,
+    &.active {
+      color: #fff;
+      border-color: darken(@core-color, 10%);
+      background-color: darken(@core-color, 10%);
+    }
+
+    &.loading {
+      &::after {
+        border-color: #fff;
+        border-right-color: transparent;
+        border-top-color: transparent;
+      }
+    }
+  }
+
+  &.btn-link {
+    color: @core-color;
+    border-color: transparent;
+    background-color: transparent;
+
+    &:hover,
+    &:focus {
+      color: darken(@core-color, 15%);
+    }
+    &:active,
+    &.active {
+      color: darken(@core-color, 25%);
+    }
+  }
+
+  // TODO: Button with icons
+}
\ No newline at end of file
diff --git a/src/utilities.less b/src/utilities.less
index d49fe37..f3b4d89 100644
--- a/src/utilities.less
+++ b/src/utilities.less
@@ -98,4 +98,10 @@
 }
 .circle {
   border-radius: 50%;
+}
+
+// Animations
+@keyframes loading {
+  0%{transform: rotate(0deg);}
+  100%{transform: rotate(360deg);}
 }
\ No newline at end of file
diff --git a/src/variables.less b/src/variables.less
index d4a8cb9..da3b46f 100644
--- a/src/variables.less
+++ b/src/variables.less
@@ -6,6 +6,10 @@
 @body-font-size: 14px;
 @body-font-family: "Helvetica Neue", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", WenQuanYi Micro Hei, sans-serif;
 
+// Colors
+@core-color: #5764C6;
+
+
 // Mixins
 .clearfix() {
   &::after {