diff --git a/modules/cybercore-ui/src/test/java/br/com/cybercore/signer/ui/theme/DesignTokenGuardrailTest.java b/modules/cybercore-ui/src/test/java/br/com/cybercore/signer/ui/theme/DesignTokenGuardrailTest.java
new file mode 100644
index 0000000..6e7289c
--- /dev/null
+++ b/modules/cybercore-ui/src/test/java/br/com/cybercore/signer/ui/theme/DesignTokenGuardrailTest.java
@@ -0,0 +1,143 @@
+package br.com.cybercore.signer.ui.theme;
+
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import java.io.BufferedReader;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Testes de guarda-corpo arquitetural para o sistema de Design Tokens do CyberCore Signer.
+ * Assegura que nenhuma cor hexadecimal solta seja introduzida fora dos blocos canônicos de tokens,
+ * garantindo conformidade com o tema escuro/claro e consistência visual rigorosa.
+ */
+class DesignTokenGuardrailTest {
+
+    private static final Pattern HEX_COLOR_PATTERN = Pattern.compile("#([0-9a-fA-F]{3,8})\\b");
+
+    @Test
+    @DisplayName("theme.css não deve conter cores hexadecimais fora dos blocos de tokens (.theme-light e .theme-dark)")
+    void shouldNotHaveHardcodedHexColorsOutsideTokenDefinitions() throws Exception {
+        InputStream stream = getClass().getResourceAsStream("/styles/theme.css");
+        assertThat(stream).withFailMessage("Arquivo /styles/theme.css não encontrado no classpath!").isNotNull();
+
+        List<String> violations = new ArrayList<>();
+
+        try (BufferedReader reader = new BufferedReader(new InputStreamReader(stream, StandardCharsets.UTF_8))) {
+            String line;
+            int lineNumber = 0;
+            boolean insideTokenBlock = false;
+            int openBracesInBlock = 0;
+
+            while ((line = reader.readLine()) != null) {
+                lineNumber++;
+                String trimmed = line.trim();
+
+                // Ignora comentários de linha inteira
+                if (trimmed.startsWith("/*") && trimmed.endsWith("*/")) {
+                    continue;
+                }
+
+                // Detecta entrada nos blocos de tokens .theme-light e .theme-dark
+                if (trimmed.contains(".theme-light") || trimmed.contains(".theme-dark")) {
+                    insideTokenBlock = true;
+                }
+
+                if (insideTokenBlock) {
+                    for (char c : line.toCharArray()) {
+                        if (c == '{') {
+                            openBracesInBlock++;
+                        } else if (c == '}') {
+                            openBracesInBlock--;
+                            if (openBracesInBlock <= 0) {
+                                insideTokenBlock = false;
+                                openBracesInBlock = 0;
+                            }
+                        }
+                    }
+                    continue; // Cores hex dentro do bloco de tokens são permitidas
+                }
+
+                // Fora dos blocos de tokens: proibir qualquer cor hexadecimal
+                // Remove comentários inline antes de testar
+                String codeOnly = line.replaceAll("/\\*.*?\\*/", "");
+                Matcher matcher = HEX_COLOR_PATTERN.matcher(codeOnly);
+                while (matcher.find()) {
+                    violations.add(String.format("Linha %d: '%s' contém cor hexadecimal solta '%s'",
+                            lineNumber, trimmed, matcher.group()));
+                }
+            }
+        }
+
+        assertThat(violations)
+                .withFailMessage("Foram encontradas cores hexadecimais soltas fora dos blocos de tokens em theme.css:\n%s",
+                        String.join("\n", violations))
+                .isEmpty();
+    }
+
+    @Test
+    @DisplayName("theme.css não deve conter seletores legados residuais serpro-*")
+    void shouldNotContainLegacySerproSelectors() throws Exception {
+        InputStream stream = getClass().getResourceAsStream("/styles/theme.css");
+        assertThat(stream).isNotNull();
+
+        List<String> legacySelectors = new ArrayList<>();
+
+        try (BufferedReader reader = new BufferedReader(new InputStreamReader(stream, StandardCharsets.UTF_8))) {
+            String line;
+            int lineNumber = 0;
+            while ((line = reader.readLine()) != null) {
+                lineNumber++;
+                if (line.toLowerCase().contains(".serpro-")) {
+                    legacySelectors.add(String.format("Linha %d: %s", lineNumber, line.trim()));
+                }
+            }
+        }
+
+        assertThat(legacySelectors)
+                .withFailMessage("Foram encontrados seletores legados .serpro-* em theme.css:\n%s",
+                        String.join("\n", legacySelectors))
+                .isEmpty();
+    }
+
+    @Test
+    @DisplayName("theme.css deve definir todos os tokens de cores semânticas primários e de superfície")
+    void shouldDefineAllRequiredSemanticColorTokens() throws Exception {
+        InputStream stream = getClass().getResourceAsStream("/styles/theme.css");
+        assertThat(stream).isNotNull();
+
+        String content;
+        try (stream) {
+            content = new String(stream.readAllBytes(), StandardCharsets.UTF_8);
+        }
+
+        String[] requiredTokens = {
+                "-fx-color-primary",
+                "-fx-color-primary-hover",
+                "-fx-color-surface",
+                "-fx-color-surface-hover",
+                "-fx-color-background",
+                "-fx-color-border",
+                "-fx-color-text",
+                "-fx-color-text-muted",
+                "-fx-color-text-inverse",
+                "-fx-color-success",
+                "-fx-color-warning",
+                "-fx-color-error"
+        };
+
+        for (String token : requiredTokens) {
+            assertThat(content)
+                    .withFailMessage("Token semântico obrigatório ausente em theme.css: %s", token)
+                    .contains(token);
+        }
+    }
+}