Dark MOde/Theme Veränderung/form Validation

style.css

@@ -1,3 +1,8 @@
+:root {
+    --main-color: #667eea;
+    --main-color-dark: #764ba2;
+}
+
 * {
     margin: 0;
     padding: 0;
@@ -275,4 +280,113 @@ footer {
     padding: 30px 20px;
     margin-top: 60px;
     font-size: 14px;
+}
+
+body.dark-mode {
+    background-color: #1a1a1a;
+    color: #e0e0e0;
+}
+
+body.dark-mode section {
+    background: #2d2d2d;
+    color: #e0e0e0;
+}
+
+body.dark-mode section h2 {
+    color: var(--main-color);
+}
+
+body.dark-mode .card {
+    background: #2d2d2d;
+    color: #e0e0e0;
+}
+
+body.dark-mode input,
+body.dark-mode textarea {
+    background: #3d3d3d;
+    color: #e0e0e0;
+    border-color: #555;
+}
+
+.controls {
+    margin-top: 20px;
+    display: flex;
+    justify-content: center;
+    align-items: center;
+    gap: 20px;
+    flex-wrap: wrap;
+}
+
+.btn-small {
+    padding: 8px 16px;
+    background: rgba(255, 255, 255, 0.2);
+    color: white;
+    border: 2px solid white;
+    border-radius: 8px;
+    cursor: pointer;
+    font-size: 14px;
+    font-weight: 600;
+    transition: all 0.3s ease;
+}
+
+.btn-small:hover {
+    background: rgba(255, 255, 255, 0.3);
+    transform: scale(1.05);
+}
+
+.color-picker {
+    display: flex;
+    gap: 10px;
+    align-items: center;
+}
+
+.color-btn {
+    width: 30px;
+    height: 30px;
+    border-radius: 50%;
+    border: 3px solid rgba(255, 255, 255, 0.3);
+    cursor: pointer;
+    transition: all 0.3s ease;
+}
+
+.color-btn:hover {
+    transform: scale(1.2);
+    border-color: white;
+}
+
+.color-btn.active {
+    border-color: white;
+    box-shadow: 0 0 10px rgba(255, 255, 255, 0.5);
+}
+
+header {
+    background: linear-gradient(135deg, var(--main-color) 0%, var(--main-color-dark) 100%);
+}
+
+section h2 {
+    color: var(--main-color);
+}
+
+#hero {
+    background: linear-gradient(135deg, var(--main-color) 0%, var(--main-color-dark) 100%);
+}
+
+#services li {
+    color: var(--main-color);
+}
+
+.card {
+    border-top: 4px solid var(--main-color);
+}
+
+.card h3 {
+    color: var(--main-color);
+}
+
+.btn {
+    background: linear-gradient(135deg, var(--main-color) 0%, var(--main-color-dark) 100%);
+}
+
+footer {
+    background: linear-gradient(135deg, var(--main-color) 0%, var(--main-color-dark) 100%);
 }