How do you verify CSS properties like color and font in Selenium?

WebElement submitBtn = driver.findElement(By.id("submitBtn"));

// Returns rgba format: "rgba(255, 87, 34, 1)"
String bgColor = submitBtn.getCssValue("background-color");
System.out.println("Background color: " + bgColor);

// Verify specific color
Assert.assertEquals(bgColor, "rgba(255, 87, 34, 1)", "Button color mismatch");

import org.openqa.selenium.support.Color;

public String rgbaToHex(String rgba) {
    return Color.fromString(rgba).asHex().toUpperCase();
}

// Usage
String rgba = submitBtn.getCssValue("background-color");
String hex = rgbaToHex(rgba); // "#FF5722"
Assert.assertEquals(hex, "#FF5722");

WebElement element = driver.findElement(By.cssSelector(".error-message"));

// Text color
String color = element.getCssValue("color");

// Font size
String fontSize = element.getCssValue("font-size"); // "16px"

// Font family
String fontFamily = element.getCssValue("font-family");

// Font weight (bold = "700")
String fontWeight = element.getCssValue("font-weight");

// Border
String border = element.getCssValue("border");

// Visibility
String visibility = element.getCssValue("visibility"); // "visible" or "hidden"

// Display
String display = element.getCssValue("display"); // "block", "none", "flex"

// Opacity
String opacity = element.getCssValue("opacity"); // "1" or "0.5"

// Text decoration (underline)
String textDecoration = element.getCssValue("text-decoration");

// Cursor type
String cursor = element.getCssValue("cursor"); // "pointer", "not-allowed"

@Test
public void verifyErrorMessageStyling() {
    // Trigger error
    driver.findElement(By.id("submitBtn")).click();

    WebElement errorMsg = driver.findElement(By.cssSelector(".error-message"));

    // Verify red color
    String rgba = errorMsg.getCssValue("color");
    String hex = Color.fromString(rgba).asHex();
    Assert.assertEquals(hex.toUpperCase(), "#FF0000", "Error text should be red");

    // Verify bold
    Assert.assertEquals(errorMsg.getCssValue("font-weight"), "700", "Error should be bold");

    // Verify visible
    Assert.assertEquals(errorMsg.getCssValue("display"), "block", "Error should be visible");
}

WebElement link = driver.findElement(By.cssSelector("nav a"));

// Before hover
String normalColor = link.getCssValue("color");

// Hover
new Actions(driver).moveToElement(link).perform();

// After hover (may need short wait for CSS transition)
Thread.sleep(300);
String hoverColor = link.getCssValue("color");

Assert.assertNotEquals(normalColor, hoverColor, "Color should change on hover");