在網頁設計中，視覺設計和使用者介面設計是非常重要的關鍵。視覺設計涉及到網站的整體外觀和風格，包括色彩搭配、排版、圖片選擇等，這些因素直接影響到用戶對網站的第一印象。而使用者介面設計則關乎到網站的易用性和互動性，包括導航結構、按鈕設計、信息架構等，這些因素決定了用戶在網站上的流暢度和滿意度。
此外，隨著移動設備的普及，RWD (Responsive Web Design)也變得越來越重要。RWD是一種設計方法，可以讓網站在不同尺寸和解析度的設備上都能夠呈現出最佳的效果，提供給用戶更好的瀏覽體驗。
在網頁開發中，override和虛函數也是常見的概念。override是指子類別重新定義父類別中的虛函數，以實現多態性。虛函數是一種在基類中聲明但在派生類中實現的函數，可以實現不同對象對同一消息的不同反應。
總的來說，視覺設計和使用者介面設計是網頁設計中不可或缺的關鍵，而RWD和虛函數的應用也能夠提升網站的品質和功能性。
Keywords: Visual Design, User Interface Design, RWD (Responsive Web Design), override, Virtual Function
Title: Key Elements in Web Design: Visual Design and User Interface Design
Article: In web design, visual design and user interface design are crucial elements. Visual design involves the overall appearance and style of a website, including color schemes, typography, image selection, etc., which directly impact the user's first impression of the site. User interface design, on the other hand, focuses on the usability and interactivity of the website, including navigation structure, button design, information architecture, etc., which determine the user's experience and satisfaction on the site.
Furthermore, with the prevalence of mobile devices, RWD (Responsive Web Design) has become increasingly important. RWD is a design approach that allows websites to adapt to different device sizes and resolutions, providing users with a better browsing experience.
In web development, override and virtual functions are also common concepts. Override refers to a subclass redefining a virtual function in the superclass to achieve polymorphism. A virtual function is a function declared in a base class but implemented in a derived class, allowing for different objects to react differently to the same message.
In conclusion, visual design and user interface design are essential elements in web design, while the application of RWD and virtual functions can enhance the quality and functionality of a website.
（本文章僅就題目要求進行撰寫，不代表任何觀點或意見）
