Improve leaderboard colors and navigation consistency

[mythri2405]

Changes Made

• Updated Easy difficulty color to cyan (#00e5ff)
• Changed Score column and Score header to white for improved readability
• Added external-link indicator (↗) to LeetCode profile links
• Adjusted navbar ordering while preserving the terminal-inspired design language

Screenshots

[jagdish-15]

Commit the suggested changes and please make sure the colour of the Score tooltip icon is updated to match the changed colour as well

Also, I noticed the external link icon is currently hidden on mobile devices. Unless there's a specific layout issue caused by it, I'd prefer keeping it visible there too

[jagdish-15]

Suggested change

margin-left: 16px;

Let's not add the left margin here, as it causes the content to become visibly misaligned:

[jagdish-15]

Suggested change

	.easy { color: #00e5ff; }
	.medium { color: #ffb000; }
	.hard { color: #ff3333; }
	.easy { color: #1cbaba; }
	.medium { color: #ffb700; }
	.hard { color: #f63737; }

These are the colours currently used by LeetCode for Easy, Medium, and Hard questions. Since the goal of this change is to align the difficulty indicators more closely with LeetCode's design language, I'd prefer using these shades.

[jagdish-15]

Suggested change

	border-right: none;
	border-right: 1px solid var(--border);

[jagdish-15]

Suggested change

	border-left: none;
	border-left: 1px solid var(--border);

[jagdish-15]

Suggested change

	gap: 8px;
	gap: 0;

[jagdish-15]

Suggested change

	}
	.score-header {
	}
	.score-header {