Restore downloaded replay CSS

PR smogon#2162 removed the CSS on downloaded replays without any
explanation. I think it was intended to save space and/or make
things bigger? But it came with a number of bugs.

- downloaded replay logs are much wider than intended
- downloaded replays now have a "battle options" button that does
  nothing
- downloaded replays have some unstyled text in e.g. popups
- MOST IMPORTANTLY: downloaded replays are no longer styled when
  you don't have an internet connection

Anyway, reverting that change fixes all these issues, and doesn't
seem to cause any new ones? This is a temporary measure while
waiting for Karthik to explain why the CSS removal was done in
the first place.

Refs smogon#2165

src/battle-log.ts

@@ -1165,6 +1165,10 @@ export class BattleLog {
 		buf += '<meta charset="utf-8" />\n';
 		buf += '<!-- version 1 -->\n';
 		buf += `<title>${BattleLog.escapeHTML(battle.tier)} replay: ${BattleLog.escapeHTML(battle.p1.name)} vs. ${BattleLog.escapeHTML(battle.p2.name)}</title>\n`;
+		// This <style> exists so that replays are readable without an internet connection
+		buf += '<style>\n';
+		buf += 'html,body {font-family:Verdana, sans-serif;font-size:10pt;margin:0;padding:0;}body{padding:12px 0;} .battle-log {font-family:Verdana, sans-serif;font-size:10pt;} .battle-log-inline {border:1px solid #AAAAAA;background:#EEF2F5;color:black;max-width:640px;margin:0 auto 80px;padding-bottom:5px;} .battle-log .inner {padding:4px 8px 0px 8px;} .battle-log .inner-preempt {padding:0 8px 4px 8px;} .battle-log .inner-after {margin-top:0.5em;} .battle-log h2 {margin:0.5em -8px;padding:4px 8px;border:1px solid #AAAAAA;background:#E0E7EA;border-left:0;border-right:0;font-family:Verdana, sans-serif;font-size:13pt;} .battle-log .chat {vertical-align:middle;padding:3px 0 3px 0;font-size:8pt;} .battle-log .chat strong {color:#40576A;} .battle-log .chat em {padding:1px 4px 1px 3px;color:#000000;font-style:normal;} .chat.mine {background:rgba(0,0,0,0.05);margin-left:-8px;margin-right:-8px;padding-left:8px;padding-right:8px;} .spoiler {color:#BBBBBB;background:#BBBBBB;padding:0px 3px;} .spoiler:hover, .spoiler:active, .spoiler-shown {color:#000000;background:#E2E2E2;padding:0px 3px;} .spoiler a {color:#BBBBBB;} .spoiler:hover a, .spoiler:active a, .spoiler-shown a {color:#2288CC;} .chat code, .chat .spoiler:hover code, .chat .spoiler:active code, .chat .spoiler-shown code {border:1px solid #C0C0C0;background:#EEEEEE;color:black;padding:0 2px;} .chat .spoiler code {border:1px solid #CCCCCC;background:#CCCCCC;color:#CCCCCC;} .battle-log .rated {padding:3px 4px;} .battle-log .rated strong {color:white;background:#89A;padding:1px 4px;border-radius:4px;} .spacer {margin-top:0.5em;} .message-announce {background:#6688AA;color:white;padding:1px 4px 2px;} .message-announce a, .broadcast-green a, .broadcast-blue a, .broadcast-red a {color:#DDEEFF;} .broadcast-green {background-color:#559955;color:white;padding:2px 4px;} .broadcast-blue {background-color:#6688AA;color:white;padding:2px 4px;} .infobox {border:1px solid #6688AA;padding:2px 4px;} .infobox-limited {max-height:200px;overflow:auto;overflow-x:hidden;} .broadcast-red {background-color:#AA5544;color:white;padding:2px 4px;} .message-learn-canlearn {font-weight:bold;color:#228822;text-decoration:underline;} .message-learn-cannotlearn {font-weight:bold;color:#CC2222;text-decoration:underline;} .message-effect-weak {font-weight:bold;color:#CC2222;} .message-effect-resist {font-weight:bold;color:#6688AA;} .message-effect-immune {font-weight:bold;color:#666666;} .message-learn-list {margin-top:0;margin-bottom:0;} .message-throttle-notice, .message-error {color:#992222;} .message-overflow, .chat small.message-overflow {font-size:0pt;} .message-overflow::before {font-size:9pt;content:\'...\';} .subtle {color:#3A4A66;}\n';
+		buf += '</style>\n';
 		buf += '<div class="wrapper replay-wrapper" style="max-width:1180px;margin:0 auto">\n';
 		buf += '<input type="hidden" name="replayid" value="' + replayid + '" />\n';
 		buf += '<div class="battle"></div><div class="battle-log"></div><div class="replay-controls"></div><div class="replay-controls-2"></div>\n';