feat: custom layout spacing

Author: subframe7536

src/layout.scss

@@ -8,6 +8,7 @@ body.app-layout-card:not(.is-mobile) {
   --pdf-background: transparent;
   --tab-divider-color: var(--color-base-35);
   --tab-active-shadow: none !important;
+  --app-layout-spacing: var(--setting-app-layout-spacing, var(--size-2-3));
 
   &.theme-light {
     --background-primary-alt: hsl(var(--base-accent-h), 14%, 95%);
@@ -105,16 +106,29 @@ body.app-layout-card:not(.is-mobile) {
 
   .mod-root {
     .workspace-tab-header-container {
-      padding-left: var(--size-4-1);
+      padding-left: var(--app-layout-spacing);
     }
     .workspace-tab-container {
-      padding: var(--size-4-1);
+      padding: var(--app-layout-spacing);
       padding-top: 0;
 
       .workspace-leaf-content {
         border-radius: var(--radius-m);
       }
     }
+    :is(
+        .workspace-tabs + .workspace-tabs.mod-top,
+        .workspace-split.mod-vertical > .workspace-tabs + .workspace-tabs,
+        .workspace-tabs + .workspace-split > .workspace-tabs,
+        .workspace-split + .workspace-tabs,
+        .workspace-split + .workspace-split:not(.mod-root) > .workspace-tabs
+      )
+      > div {
+      padding-left: 0;
+    }
+    .workspace-tabs:not(.mod-top) {
+      margin-top: -4px;
+    }
   }
 
   .workspace-tab-header {

src/style-settings/_index.scss

@@ -192,7 +192,8 @@ body:not(.calendar-swap-year-month)
 body:not(.app-layout-card)
   .setting-item:is(
     [data-id='app-layout-card-bg'],
-    [data-id='app-layout-card-border']
+    [data-id='app-layout-card-border'],
+    [data-id='setting-app-layout-spacing']
   ),
 body:not(.app-layout-card.app-layout-card-custom)
   .setting-item:is(

src/style-settings/basic.ts

@@ -140,6 +140,16 @@ export default Settings.create('maple-basic', 'Maple Basic').children([
     .addClassToggle('app-layout-card-border', {
       title: { en: 'Add Border For Card', zh: '为卡片添加边框' },
     })
+    .addVarNumSlider(
+      'setting-app-layout-spacing',
+      {
+        title: {
+          en: 'Card Spacing',
+          zh: '卡片间距',
+        },
+      },
+      { default: 6, max: 16, min: 2, step: 0.5, format: 'px' },
+    )
     .addClassSelect(
       'app-layout-card-bg',
       {

src/workspace/tab.scss

@@ -37,7 +37,7 @@
         &-inner {
           margin-top: var(--size-4-1);
           padding-bottom: var(--size-4-1);
-          padding-left: var(--size-4-1);
+          padding-left: 5px;
 
           &-close-button {
             padding: var(--size-2-1);