diff --git a/experiment_results_visualization/css/theme.css b/experiment_results_visualization/css/theme.css
new file mode 100644
index 0000000..0fc9bd8
--- /dev/null
+++ b/experiment_results_visualization/css/theme.css
@@ -0,0 +1,82 @@
+:root {
+  --color-pinned-primary: #2b6cb0;
+  --color-pinned-accent: #63b3ed;
+  --color-unpinned-primary: #c53030;
+  --color-unpinned-accent: #fc8181;
+  --color-bg: #ffffff;
+  --color-text: #1a202c;
+  --color-surface: #f7fafc;
+  --color-border: #e2e8f0;
+  --transition-default: 0.3s ease-in-out;
+}
+
+/* Section: Pinned/Unpinned Colors */
+.pinned-data {
+  background-color: var(--color-pinned-accent);
+  color: var(--color-text);
+  border-left: 4px solid var(--color-pinned-primary);
+  transition: background-color var(--transition-default), border-color var(--transition-default);
+}
+
+.pinned-data:hover {
+  background-color: var(--color-pinned-primary);
+  color: #ffffff;
+}
+
+.unpinned-data {
+  background-color: var(--color-unpinned-accent);
+  color: var(--color-text);
+  border-left: 4px solid var(--color-unpinned-primary);
+  transition: background-color var(--transition-default), border-color var(--transition-default);
+}
+
+.unpinned-data:hover {
+  background-color: var(--color-unpinned-primary);
+  color: #ffffff;
+}
+
+/* Section: Dark Mode */
+body.dark-theme {
+  --color-bg: #1a202c;
+  --color-text: #edf2f7;
+  --color-surface: #2d3748;
+  --color-border: #4a5568;
+  background-color: var(--color-bg);
+  color: var(--color-text);
+}
+
+body.dark-theme .pinned-data {
+  background-color: #2c5282;
+  border-left-color: #2b6cb0;
+  color: var(--color-text);
+}
+
+body.dark-theme .pinned-data:hover {
+  background-color: var(--color-pinned-primary);
+  color: #ffffff;
+}
+
+body.dark-theme .unpinned-data {
+  background-color: #822727;
+  border-left-color: #c53030;
+  color: var(--color-text);
+}
+
+body.dark-theme .unpinned-data:hover {
+  background-color: var(--color-unpinned-primary);
+  color: #ffffff;
+}
+
+/* Footer copyright */
+footer {
+  text-align: center;
+  font-size: 0.875rem;
+  color: var(--color-text);
+  margin-top: 2rem;
+}
+
+footer::after {
+  content: "© 2026 Donau2Space.de";
+  display: block;
+  margin-top: 0.25rem;
+}
\ No newline at end of file