#$*$@$*$ Elaborate on the theoretical principles behind the design and analysis of structural elements in civil engineering, focusing on the application of load$-$bearing theories, material properties, and safety factors. Discuss how these principles guide the selection of materials and the configuration of structural components such as beams, columns, and slabs. Highlight the importance of understanding stress$-$strain relationships, load distribution, and the potential for material failure under various conditions. Additionally, explain how the concept of factor of safety is integrated into the design process to ensure the reliability and durability of structures. Include a discussion on how modern computational tools and finite element analysis $($FEA$)$ have enhanced the precision and efficiency of structural engineering design, allowing for more complex and optimized structures. Describe how these tools help engineers simulate real$-$world conditions, predict potential issues, and iterate on designs to achieve optimal performance while adhering to regulatory standards and codes.