diff --git a/src/features/guides/components/FileUpload.css b/src/features/guides/components/FileUpload.css
index 54de590..19f5d47 100644
--- a/src/features/guides/components/FileUpload.css
+++ b/src/features/guides/components/FileUpload.css
@@ -3,14 +3,14 @@
     place-items: center;
     cursor: pointer;
     border-style: dashed;
-    padding: 2rem;
+    padding: var(--size-lg);
     font-weight: bold;
 
     &:hover,
     &:focus-visible {
-        border-color: #ff770080;
-        color: #ff7700;
-        background-color: #ff770010;
+        border-color: var(--color-accent-border);
+        color: var(--color-accent);
+        background-color: var(--color-accent-bg-subtle);
     }
 }
 
diff --git a/src/features/guides/components/Frame.css b/src/features/guides/components/Frame.css
index 74adc21..cbf8e5b 100644
--- a/src/features/guides/components/Frame.css
+++ b/src/features/guides/components/Frame.css
@@ -1,27 +1,22 @@
 .frame {
-    padding: 1rem;
-    background: #ddd;
-
+    padding: var(--size-md);
+    background: var(--color-bg-panel);
+    border-left: 3px solid var(--color-accent-border);
     display: flex;
     flex-direction: column;
-    gap: 1rem;
+    gap: var(--size-md);
+    border-radius: var(--radius);
 }
 
 .frame .buttons {
     display: flex;
-    gap: 1rem;
+    gap: var(--size-md);
 }
 
 .frame .buttons button {
-    padding: 0.5rem 1rem;
+    padding: var(--size-sm) var(--size-md);
 }
 
 .frame .buttons .remove {
     margin-left: auto;
 }
-
-.frame .steps {
-    display: flex;
-    flex-direction: column;
-    gap: 1rem;
-}
diff --git a/src/features/guides/components/Step.css b/src/features/guides/components/Step.css
index 99113b8..4c59448 100644
--- a/src/features/guides/components/Step.css
+++ b/src/features/guides/components/Step.css
@@ -1,12 +1,12 @@
 .step {
     display: flex;
-    gap: 1rem;
+    gap: var(--size-md);
 }
 
 .step label {
     flex-direction: row;
     align-items: center;
-    gap: 0.5rem;
+    gap: var(--size-sm);
     flex: 1;
 }
 
diff --git a/src/features/guides/routes/Guide.css b/src/features/guides/routes/Guide.css
index 4005065..2d82ec1 100644
--- a/src/features/guides/routes/Guide.css
+++ b/src/features/guides/routes/Guide.css
@@ -1,73 +1,61 @@
 main:has(.guide) {
-    padding: 1rem 7rem;
+    padding: var(--size-md) 7rem;
     display: flex;
     justify-content: center;
 }
-
 .guide__frames {
     display: flex;
     flex-direction: column;
-    gap: 3rem;
+    gap: var(--size-xl);
 }
 .guide {
     max-width: 600px;
-
     .delete-button {
         position: absolute;
-        bottom: 1rem;
-        right: 1rem;
+        bottom: var(--size-md);
+        right: var(--size-md);
     }
-
     .edit-button {
         position: absolute;
-        top: 1rem;
+        top: var(--size-md);
         right: 8rem;
     }
-
     .export-button {
         position: absolute;
-        top: 1rem;
-        right: 1rem;
+        top: var(--size-md);
+        right: var(--size-md);
     }
-
     .guide__frame {
-        padding: 1rem;
-        background-color: #dedede;
+        padding: var(--size-md);
+        background-color: var(--color-bg-panel);
         display: flex;
         flex-direction: column;
-        gap: 0.5rem;
+        gap: var(--size-sm);
     }
-
     .guide__frame img {
         max-height: 350px;
         object-fit: contain;
         object-position: left center;
     }
-
     .guide__frame ol {
-        margin-left: 1rem;
+        margin-left: var(--size-md);
     }
 }
-
 @media print {
     main:has(.guide) {
         padding: 0rem;
         justify-content: flex-start;
     }
-
     .guide__frames {
         display: block;
     }
-
     .guide__frame {
         position: relative;
         break-inside: avoid;
         page-break-inside: avoid;
-        background-color: #dedede;
-
-        margin: 2rem 0;
+        background-color: var(--color-bg-panel);
+        margin: var(--size-lg) 0;
     }
-
     .guide__frame img {
         max-width: 100%;
         max-height: 100px;
diff --git a/src/features/guides/routes/Guide.tsx b/src/features/guides/routes/Guide.tsx
index 419094d..779b47b 100644
--- a/src/features/guides/routes/Guide.tsx
+++ b/src/features/guides/routes/Guide.tsx
@@ -20,7 +20,7 @@ export default function Guide() {
 
       <div className="guide__frames">
         {guide.frames.map((frame, index) => (
-          <div key={index} className="guide__frame">
+          <div key={index} className="guide__frame frame">
             <h2>{frame.title}</h2>
             <img src={URL.createObjectURL(frame.file)} alt={frame.title} />
 
diff --git a/src/features/guides/routes/GuideForm.css b/src/features/guides/routes/GuideForm.css
index 2cfaa29..4f54a19 100644
--- a/src/features/guides/routes/GuideForm.css
+++ b/src/features/guides/routes/GuideForm.css
@@ -3,16 +3,13 @@
     flex-direction: column;
     align-items: center;
 }
-
 .new-guide__form {
     display: flex;
     flex-direction: column;
-    gap: 2rem;
-
+    gap: var(--size-lg);
     width: 100%;
     max-width: 540px;
 }
-
 .new-guide__form label {
     display: flex;
     flex-direction: column;
diff --git a/src/styles/App.css b/src/styles/App.css
index 75713d3..3ccca6c 100644
--- a/src/styles/App.css
+++ b/src/styles/App.css
@@ -1,114 +1,114 @@
 :root {
+    /* color */
     --color-border: #ccc;
     --color-bg-sidebar: #eee;
-    --sidebar-width: 250px;
-    --gap-nav: 1rem;
-}
+    --color-bg-panel: #fafafa;
+    --color-accent: #ff7700;
+    --color-accent-hover: #ff9900;
+    --color-accent-border: #ff770080;
+    --color-accent-bg-subtle: #ff770010;
 
+    /* layout */
+    --sidebar-width: 250px;
+    --radius: 4px;
+
+    /* spacing scale */
+    --size-xs2: 0.125rem;
+    --size-xs: 0.25rem;
+    --size-sm: 0.5rem;
+    --size-md: 1rem;
+    --size-lg: 2rem;
+    --size-xl: 3rem;
+}
 html,
 body {
     font-family: system-ui, Arial, sans-serif;
     position: relative;
 }
-
 #root {
     min-height: 100vh;
 }
-
 .app-body {
     display: flex;
     flex: 1;
 }
-
 header {
     position: fixed;
     height: 100%;
     width: var(--sidebar-width);
-    padding: 1rem;
+    padding: var(--size-md);
     display: flex;
     flex-direction: column;
     align-items: center;
-    gap: var(--gap-nav);
+    gap: var(--size-sm);
     border-right: 3px solid var(--color-border);
     background-color: var(--color-bg-sidebar);
-
     .main-title a {
         text-decoration: none;
         color: inherit;
     }
-
     .create-new-guide-btn {
-        padding: 0.5rem 1rem;
-        border-radius: 4px;
-        background-color: #ff7700;
+        padding: var(--size-sm) var(--size-md);
+        border-radius: var(--radius);
+        background-color: var(--color-accent);
         color: #fff;
         text-decoration: none;
         font-weight: bold;
         text-align: center;
     }
-
     .guide-list {
         list-style: none;
         padding: 0;
-        margin-top: 0.5rem;
+        margin-top: var(--size-sm);
         display: flex;
         flex-direction: column;
-        gap: 0.5rem;
+        gap: var(--size-sm);
     }
 }
-
 main {
     margin-left: var(--sidebar-width);
     flex: 1;
-    padding: 1rem;
+    padding: var(--size-md);
 }
-
 footer {
     position: fixed;
     bottom: 0;
     left: 0;
     margin: 0 auto;
-    padding: 0.5rem;
+    padding: var(--size-sm);
     text-align: center;
     width: var(--sidebar-width);
 }
-
 nav {
     display: flex;
     flex-direction: column;
     height: 100%;
-    padding-bottom: 2rem;
+    padding-bottom: var(--size-lg);
     width: 100%;
-
     a {
-        padding: 0.6rem 1rem 0.5rem;
-        border-radius: 4px;
+        padding: 0.6rem var(--size-md) 0.5rem;
+        border-radius: var(--radius);
         line-height: 1;
         display: block;
     }
-
     .settings-btn {
         margin-top: auto;
         align-self: center;
         font-weight: bold;
     }
-
     .settings-btn.active {
         margin-top: auto;
         align-self: center;
-        color: #ff7700;
+        color: var(--color-accent);
     }
-
     h2 {
-        margin-top: 2rem;
+        margin-top: var(--size-lg);
         font-size: 1rem;
         opacity: 0.5;
     }
-
     li {
         width: 100%;
     }
-
     .guide-list a {
         transition:
             background-color 0.125s,
@@ -116,25 +116,22 @@ nav {
         background-color: #fff;
         border-left: 4px solid var(--color-border);
     }
-
     .guide-list a.active {
         background-color: #fff;
-        border-left: 4px solid #ff7700;
+        border-left: 4px solid var(--color-accent);
     }
     .guide-list a:hover:not(.active) {
-        border-left: 4px solid #ff9900;
+        border-left: 4px solid var(--color-accent-hover);
         opacity: 0.8;
     }
 }
-
 ul {
     padding: 0;
     display: flex;
     flex-direction: column;
-    gap: 0.125rem;
+    gap: var(--size-xs);
     list-style: none;
 }
-
 a,
 input,
 button,
@@ -144,37 +141,30 @@ textarea {
     font-size: inherit;
     color: inherit;
 }
-
 a {
     text-decoration: none;
 }
-
 input,
 textarea,
 .file-upload {
-    border: 3px solid var(--color-border);
-    border-radius: 4px;
-    padding: 0.25rem;
+    border: 2px solid var(--color-bg-sidebar);
+    border-radius: var(--radius);
+    padding: var(--size-sm);
 }
-
 textarea {
     resize: none;
     height: 5rem;
 }
-
 hr {
-    margin: 1rem 0;
+    margin: var(--size-md) 0;
     border: none;
     height: 3px;
-    background-color: var(--color-border);
-    border-radius: 4px;
+    background-color: var(--color-bg-sidebar);
+    border-radius: var(--radius);
 }
-
 :focus-visible {
-    outline: 2px solid #ff7700;
-    outline-offset: 2px;
+    border: 2px solid var(--color-accent);
 }
-
 @media print {
     header,
     footer,