diff --git a/data_visualization/css/base.css b/data_visualization/css/base.css
new file mode 100644
index 0000000..285e56c
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+++ b/data_visualization/css/base.css
@@ -0,0 +1,106 @@
+/* =========================================
+   Section: Variables and Reset
+   ========================================= */
+
+:root {
+  --color-bg: #0b0c10;
+  --color-surface: #1f2833;
+  --color-text: #c5c6c7;
+  --color-accent: #66fcf1;
+  --color-primary: #45a29e;
+  --font-base: 'Arial', sans-serif;
+  --spacing-xs: 0.25rem;
+  --spacing-sm: 0.5rem;
+  --spacing-md: 1rem;
+  --spacing-lg: 2rem;
+  --radius-sm: 4px;
+  --radius-md: 8px;
+  --transition-fast: 0.2s ease;
+  --bp-sm: 640px;
+  --bp-md: 1024px;
+}
+
+* {
+  box-sizing: border-box;
+  margin: 0;
+  padding: 0;
+}
+
+html, body {
+  height: 100%;
+  scroll-behavior: smooth;
+}
+
+body {
+  background-color: var(--color-bg);
+  color: var(--color-text);
+  font-family: var(--font-base);
+  line-height: 1.6;
+  -webkit-font-smoothing: antialiased;
+  -moz-osx-font-smoothing: grayscale;
+}
+
+/* =========================================
+   Section: Typography
+   ========================================= */
+
+h1, h2, p {
+  color: var(--color-text);
+  margin-bottom: var(--spacing-md);
+}
+
+h1 {
+  font-size: 1.8rem;
+  font-weight: 700;
+  color: var(--color-accent);
+}
+
+h2 {
+  font-size: 1.4rem;
+  font-weight: 600;
+  color: var(--color-primary);
+}
+
+p {
+  font-size: 1rem;
+  line-height: 1.5;
+}
+
+@media (min-width: var(--bp-sm)) {
+  h1 {
+    font-size: 2.2rem;
+  }
+
+  h2 {
+    font-size: 1.6rem;
+  }
+}
+
+@media (min-width: var(--bp-md)) {
+  h1 {
+    font-size: 2.6rem;
+  }
+
+  h2 {
+    font-size: 1.8rem;
+  }
+  
+  p {
+    font-size: 1.1rem;
+  }
+}
+
+/* Footer copyright */
+footer {
+  text-align: center;
+  font-size: 0.9rem;
+  padding: var(--spacing-md) 0;
+  color: var(--color-text);
+}
+
+footer::after {
+  content: "© 2026 Donau2Space.de";
+  display: block;
+  margin-top: var(--spacing-sm);
+  color: var(--color-primary);
+}