1) Hint: Use display: flex, justify-content: space-between, and padding.
2) Hint: Use box-shadow, border-radius, and hover effects.
3) Hint: Use a class like .dark-mode and change background and text colors.
4) Hint: Use CSS Grid and media queries.
5) Hint: Use transition, transform: scale(1.1);, and a bright color.
6) Hint: Use position: sticky; top: 0; and z-index.
7) Hint: Use Flexbox or Grid and background-color for emphasis.
8) Hint: Use @keyframes and animation to rotate a div.
9) Hint: Use the :focus pseudo-class.
10) Hint: Use vertical Flexbox or pseudo-elements like ::before.