diff --git a/demo/CodeGen.vue b/demo/CodeGen.vue
index 40475eb..2cc14af 100644
--- a/demo/CodeGen.vue
+++ b/demo/CodeGen.vue
@@ -458,14 +458,14 @@ onBeforeUnmount(() => {
   display: flex;
   justify-content: center;
   align-items: stretch;
-  gap: 16px;
-  padding: 16px;
+  gap: var(--space-4);
+  padding: var(--space-4);
   border-bottom: 1px solid var(--border);
 
   label {
     display: flex;
     align-items: center;
-    gap: 6px;
+    gap: var(--space-2);
     color: var(--muted);
   }
 
@@ -513,8 +513,8 @@ onBeforeUnmount(() => {
 
 .copy {
   position: absolute;
-  right: 10px;
-  top: 10px;
+  right: var(--space-2);
+  top: var(--space-2);
   border-radius: var(--r-m);
   border: 1px solid var(--border);
 }
@@ -524,8 +524,8 @@ onBeforeUnmount(() => {
   z-index: 2147483647;
   bottom: 2rem;
   left: 50%;
-  padding: 0.5rem 0.75rem;
-  background-color: var(--text);
+  padding: var(--space-2) var(--space-3);
+  background-color: color-mix(in srgb, var(--text) 88%, var(--surface) 12%);
   box-shadow: var(--shadow);
   color: var(--surface);
   font-size: 0.875rem;
@@ -537,6 +537,20 @@ onBeforeUnmount(() => {
     opacity 0.2s;
 }
 
+html.dark .message {
+  background-color: color-mix(
+    in srgb,
+    var(--surface) 72%,
+    var(--border) 28%
+  );
+  color: var(--heading);
+  border: 1px solid color-mix(
+    in srgb,
+    var(--border) 45%,
+    transparent 55%
+  );
+}
+
 .message.open {
   transform: translate(-50%, 0);
   opacity: 1;
diff --git a/demo/Demo.vue b/demo/Demo.vue
index 989dfdb..5ba7765 100644
--- a/demo/Demo.vue
+++ b/demo/Demo.vue
@@ -96,7 +96,7 @@ watch(codeOpen, applyCodegenState, { immediate: true });
       <a href="https://github.com/ecomfe/vue-echarts">Vue ECharts</a>
     </h1>
     <p class="desc">Vue.js component for Apache ECharts™.</p>
-    <p>
+    <p class="badges">
       <a href="https://npmjs.com/package/vue-echarts"
         ><img alt="npm version" src="https://img.shields.io/npm/v/vue-echarts"
       /></a>
@@ -268,6 +268,15 @@ h3 {
   }
 }
 
+.badges {
+  display: flex;
+  gap: var(--space-2);
+
+  a {
+    display: flex;
+  }
+}
+
 p small {
   font-size: 0.8rem;
   color: var(--muted);
@@ -317,14 +326,14 @@ textarea {
   display: flex;
   justify-content: center;
   align-items: center;
-  gap: 10px;
+  gap: calc(var(--space-1) * 2.5);
   margin: 3.5rem 0 1.6rem;
   color: var(--muted);
 }
 .examples-head .examples-deco {
   display: inline-flex;
   align-items: center;
-  gap: 10px;
+  gap: calc(var(--space-1) * 2.5);
   color: inherit;
   text-decoration: none;
 }
@@ -347,13 +356,13 @@ textarea {
 
 .toolbar {
   position: fixed;
-  top: 16px;
-  left: 16px;
+  top: var(--space-4);
+  left: var(--space-4);
   z-index: 1000;
   display: inline-flex;
   align-items: center;
-  gap: 12px;
-  padding: 8px 12px;
+  gap: var(--space-3);
+  padding: var(--space-2) var(--space-3);
   border-radius: var(--r-l);
   border: 1px solid var(--border);
   background: color-mix(in srgb, var(--surface) 50%, transparent);
@@ -367,7 +376,7 @@ textarea {
   display: inline-flex;
   align-items: stretch;
   gap: 0;
-  padding: 2px;
+  padding: calc(var(--space-1) * 0.5);
   border: 1px solid var(--border);
   border-radius: var(--r-m);
   background: var(--surface);
@@ -378,11 +387,11 @@ textarea {
 
 .toggle .indicator {
   position: absolute;
-  top: 3px;
-  bottom: 3px;
-  left: 3px;
-  width: calc(50% - 3px);
-  border-radius: calc(var(--r-m) - 3px);
+  top: calc(var(--space-1) * 0.75);
+  bottom: calc(var(--space-1) * 0.75);
+  left: calc(var(--space-1) * 0.75);
+  width: calc(50% - var(--space-1) * 0.75);
+  border-radius: calc(var(--r-m) - var(--space-1) * 0.75);
   background: color-mix(in srgb, var(--accent) 18%, var(--surface) 82%);
   transition: transform 0.25s cubic-bezier(0.34, 1.56, 0.64, 1);
 }
@@ -403,7 +412,6 @@ textarea {
   background: none;
   color: var(--muted);
   font-size: 0.875rem;
-  font-weight: 500;
   transition: color 0.2s ease;
   display: inline-flex;
   align-items: center;
@@ -438,7 +446,6 @@ textarea {
 }
 
 .codegen {
-  font-weight: 500;
   padding: 0 1rem;
 }
 
@@ -448,11 +455,11 @@ textarea {
 
 @media (max-width: 640px) {
   body {
-    padding-bottom: 96px;
+    padding-bottom: calc(var(--space-1) * 24);
   }
 
   .examples-head .examples-deco {
-    gap: 8px;
+    gap: var(--space-2);
   }
   .examples-head .examples-deco .rule {
     width: 36px;
@@ -460,11 +467,11 @@ textarea {
 
   .toolbar {
     top: auto;
-    bottom: 20px;
+    bottom: calc(var(--space-1) * 5);
     left: 50%;
     transform: translateX(-50%);
-    gap: 8px;
-    padding: 6px 10px;
+    gap: var(--space-2);
+    padding: calc(var(--space-1) * 1.5) calc(var(--space-1) * 2.5);
     border-radius: var(--r-m);
   }
 
@@ -477,11 +484,11 @@ textarea {
   }
 
   .toggle .indicator {
-    top: 2px;
-    bottom: 2px;
-    left: 2px;
-    width: calc(50% - 2px);
-    border-radius: calc(var(--r-m) - 4px);
+    top: calc(var(--space-1) * 0.5);
+    bottom: calc(var(--space-1) * 0.5);
+    left: calc(var(--space-1) * 0.5);
+    width: calc(50% - var(--space-1) * 0.5);
+    border-radius: calc(var(--r-m) - var(--space-1));
   }
 
   .codegen {
@@ -572,12 +579,9 @@ input:not([type="checkbox"]):not([type="radio"]) {
   line-height: 1.2;
 }
 
-button {
-  cursor: pointer;
-  font-weight: 500;
-}
-
-select {
+button,
+select,
+label {
   cursor: pointer;
 }
 
@@ -686,49 +690,6 @@ x-vue-echarts {
   }
 }
 
-@media (max-width: 980px) {
-  p {
-    select {
-      text-indent: calc(50% - 1rem);
-    }
-
-    button,
-    input,
-    select,
-    label {
-      flex: 1 0;
-      margin: 0 0.5rem;
-      max-width: 40vw;
-      font-size: 0.8rem;
-    }
-
-    input[type="checkbox"] {
-      display: none;
-
-      &:checked + label {
-        background: color-mix(in srgb, var(--accent) 30%, var(--surface) 70%);
-        border-color: color-mix(in srgb, var(--accent) 45%, var(--border) 55%);
-        color: var(--surface);
-      }
-
-      & + label {
-        display: inline-flex;
-        align-items: center;
-        justify-content: center;
-        padding: 0 0.75rem;
-        height: 2.25rem;
-        border: 1px solid var(--border);
-        border-radius: var(--r-m);
-        background: var(--surface);
-        transition:
-          background-color 0.15s ease,
-          color 0.15s ease,
-          border-color 0.15s ease;
-      }
-    }
-  }
-}
-
 @media (max-width: 480px) {
   body .codegen {
     display: none !important;
diff --git a/demo/components/MonacoCodeBlock.vue b/demo/components/MonacoCodeBlock.vue
index aa4b340..a63b172 100644
--- a/demo/components/MonacoCodeBlock.vue
+++ b/demo/components/MonacoCodeBlock.vue
@@ -34,7 +34,7 @@ watch(isDark, colorize);
 <style scoped>
 .code-block {
   margin: 0;
-  padding: 12px;
+  padding: var(--space-3);
   font-size: 13px;
   line-height: 1.4;
   overflow: auto;
diff --git a/demo/examples/Example.vue b/demo/examples/Example.vue
index f6ad5c3..785871b 100644
--- a/demo/examples/Example.vue
+++ b/demo/examples/Example.vue
@@ -78,14 +78,14 @@ const badges = computed<string[]>(() => {
   justify-content: center;
   align-items: center;
   flex-wrap: wrap;
-  gap: 8px;
+  gap: var(--space-2);
   margin-top: 0.5rem;
 }
 
 .badge {
   display: inline-flex;
   align-items: center;
-  gap: 6px;
+  gap: calc(var(--space-1) * 1.5);
   padding: 0.26rem 0.72rem;
   font-weight: 500;
   font-size: 0.78rem;
@@ -120,8 +120,113 @@ const badges = computed<string[]>(() => {
   display: flex;
   justify-content: center;
   align-items: center;
-  gap: 8px;
-  margin-top: 0.5rem;
+  flex-wrap: wrap;
+  gap: var(--space-2);
+  margin-top: calc(var(--space-1) * 2);
+}
+
+.actions > * {
+  margin: 0;
+}
+
+.actions input[type="checkbox"] {
+  position: absolute;
+  width: 1px;
+  height: 1px;
+  padding: 0;
+  margin: -1px;
+  overflow: hidden;
+  clip: rect(0, 0, 0, 0);
+  white-space: nowrap;
+  border: 0;
+}
+
+.actions input[type="checkbox"] + label {
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  gap: var(--space-2);
+  padding: 0 var(--space-2);
+  height: 2.25rem;
+  border-radius: var(--r-m);
+  border: 1px solid var(--border);
+  background: var(--surface);
+  color: var(--heading);
+  font-size: 0.9rem;
+  font-weight: 500;
+  transition:
+    background-color 0.2s ease,
+    color 0.2s ease,
+    border-color 0.2s ease;
+}
+
+.actions input[type="checkbox"] + label::before {
+  content: "";
+  width: 1.25rem;
+  height: 1.25rem;
+  border-radius: calc(var(--r-s) * 0.9);
+  border: 2px solid color-mix(in srgb, var(--accent) 35%, var(--border) 65%);
+  background-color: var(--surface);
+  background-repeat: no-repeat;
+  background-position: center;
+  background-size: 95%;
+  transition:
+    background-color 0.2s ease,
+    border-color 0.2s ease,
+    background-image 0.2s ease;
+}
+
+.actions input[type="checkbox"] + label:hover {
+  border-color: var(--border);
+  background: var(--surface-2);
+}
+
+.actions input[type="checkbox"]:checked + label {
+  border-color: color-mix(in srgb, var(--accent) 70%, var(--border) 30%);
+  color: var(--accent-strong);
+}
+
+.actions input[type="checkbox"]:checked + label::before {
+  border-color: var(--accent-strong);
+  background-color: var(--accent-strong);
+  background-image: url("data:image/svg+xml,%3Csvg%20xmlns='http://www.w3.org/2000/svg'%20viewBox='0%200%2016%2016'%3E%3Cpath%20fill='%23ffffff'%20d='M13.6%204.2a.75.75%200%2000-1.2-.9L6.8%2010%204.1%207.3a.75.75%200%2010-1.2%201l3.2%203.2c.3.3.8.3%201.1%200l6.4-7.3Z'/%3E%3C/svg%3E");
+}
+
+.actions input[type="checkbox"]:focus-visible + label {
+  outline: none;
+  border-color: var(--accent);
+  outline: 2px solid color-mix(in srgb, var(--accent) 45%, transparent);
+  outline-offset: 2px;
+}
+
+@media (max-width: 720px) {
+  .actions {
+    flex-direction: column;
+    align-items: center;
+    gap: var(--space-2);
+  }
+
+  .actions button,
+  .actions select,
+  .actions input[type="checkbox"] + label {
+    width: auto;
+    min-width: min(150px, 100%);
+    font-size: 0.84rem;
+    height: 2.25rem;
+  }
+
+  .actions select {
+    text-align-last: center;
+  }
+
+  .actions button,
+  .actions select {
+    padding-inline: var(--space-2);
+  }
+
+  .actions input[type="checkbox"] + label {
+    padding: 0 var(--space-2);
+  }
 }
 
 @media (max-width: 980px) {
@@ -149,7 +254,7 @@ const badges = computed<string[]>(() => {
     }
 
     & + & {
-      margin-left: 30px;
+      margin-left: calc(var(--space-1) * 7.5);
     }
   }
 }
diff --git a/demo/examples/LineChart.vue b/demo/examples/LineChart.vue
index 9b9539e..dd911af 100644
--- a/demo/examples/LineChart.vue
+++ b/demo/examples/LineChart.vue
@@ -145,7 +145,7 @@ function getDatasetRows(option: Option): Array<string | number>[] {
       <template #dataView="chartOption">
         <table
           v-if="getDatasetRows(chartOption).length"
-          style="margin: 20px auto"
+          style="margin: var(--space-5) auto"
         >
           <thead>
             <tr>
@@ -183,6 +183,6 @@ function getDatasetRows(option: Option): Array<string | number>[] {
 <style scoped>
 th,
 td {
-  padding: 4px 8px;
+  padding: var(--space-1) var(--space-2);
 }
 </style>
diff --git a/demo/global.css b/demo/global.css
index a0efc55..dcfb6fa 100644
--- a/demo/global.css
+++ b/demo/global.css
@@ -60,7 +60,7 @@
   /* Focus */
   --focus: 0 0 0 2px var(--ring);
 
-  /* Radius & spacing (8px scale) */
+  /* Radius & spacing (4px base scale) */
   --r-s: 4px;
   --r-m: 8px;
   --r-l: 12px;