diff --git a/experiment_results_visualization/css/base.css b/experiment_results_visualization/css/base.css
new file mode 100644
index 0000000..44fda76
--- /dev/null
+++ b/experiment_results_visualization/css/base.css
@@ -0,0 +1,85 @@
+:root {
+  --color-bg: #f9fafb;
+  --color-text: #1a1a1a;
+  --color-primary: #2563eb;
+  --color-secondary: #6b7280;
+  --color-border: #e5e7eb;
+  --font-base: 'Segoe UI', Roboto, sans-serif;
+  --font-size-base: 1rem;
+  --spacing-xs: 0.25rem;
+  --spacing-sm: 0.5rem;
+  --spacing-md: 1rem;
+  --spacing-lg: 2rem;
+  --breakpoint-sm: 640px;
+  --breakpoint-lg: 1024px;
+}
+
+/* === Root & Reset === */
+* {
+  margin: 0;
+  padding: 0;
+  box-sizing: border-box;
+}
+
+html, body {
+  height: 100%;
+  font-family: var(--font-base);
+  font-size: var(--font-size-base);
+  color: var(--color-text);
+  background-color: var(--color-bg);
+  line-height: 1.5;
+  -webkit-font-smoothing: antialiased;
+  -moz-osx-font-smoothing: grayscale;
+}
+
+body {
+  display: flex;
+  flex-direction: column;
+  min-height: 100vh;
+}
+
+/* === App Shell Layout === */
+.app-shell {
+  display: flex;
+  flex-direction: column;
+  min-height: 100vh;
+}
+
+.app-header {
+  flex: 0 0 auto;
+  padding: var(--spacing-md);
+  background-color: var(--color-primary);
+  color: #ffffff;
+}
+
+.app-footer {
+  flex: 0 0 auto;
+  padding: var(--spacing-sm) var(--spacing-md);
+  background-color: var(--color-border);
+  color: var(--color-secondary);
+  text-align: center;
+  font-size: 0.875rem;
+}
+
+@media (min-width: var(--breakpoint-sm)) {
+  .app-header {
+    padding: var(--spacing-lg);
+  }
+
+  .app-footer {
+    font-size: 1rem;
+  }
+}
+
+@media (min-width: var(--breakpoint-lg)) {
+  .app-shell {
+    flex-direction: column;
+  }
+}
+
+/* === Footer Copyright === */
+.app-footer::after {
+  content: "© 2026 Donau2Space.de";
+  display: block;
+  margin-top: var(--spacing-xs);
+}
\ No newline at end of file