/* Shared styles for every browser lab page (web/<course>/index.html). */
:root{
  --bg:#f6f6f7; --surface:#ffffff; --border:#e3e3e6; --text:#0b0b0c; --muted:#66666e;
  --accent:#12703a; --accent-soft:#e2efe6; --on-accent:#ffffff; --code-bg:#ececee; --ok:#12703a; --ok-soft:#e2efe6;
  --bad:#b3261e; --link:#12703a; --term:#0e0e10; --try-bg:#f1f1f3; --try-border:#dcdce0; --try-accent:#3f3f46;
}
@media (prefers-color-scheme: dark){
  :root:not([data-theme="light"]){
    --bg:#0b0b0c; --surface:#141416; --border:#27272b; --text:#e8e8eb; --muted:#8d8d95;
    --accent:#22a861; --accent-soft:#13251a; --on-accent:#04140a; --code-bg:#1d1d20; --ok:#22a861; --ok-soft:#13251a;
    --bad:#f08a80; --link:#2bb56b; --try-bg:#161618; --try-border:#2a2a2f; --try-accent:#b4b4bc;
  }
}
:root[data-theme="dark"]{
  --bg:#0b0b0c; --surface:#141416; --border:#27272b; --text:#e8e8eb; --muted:#8d8d95;
  --accent:#22a861; --accent-soft:#13251a; --on-accent:#04140a; --code-bg:#1d1d20; --ok:#22a861; --ok-soft:#13251a;
  --bad:#f08a80; --link:#2bb56b; --try-bg:#161618; --try-border:#2a2a2f; --try-accent:#b4b4bc;
}
*{box-sizing:border-box}
/* On a wide screen the page itself never scrolls (the lesson and terminal
   do). Locking it stops Safari scrolling the header out of reach when the
   lesson scrolls a challenge into view. Phones scroll the page (see below). */
html,body{height:100%;overflow:hidden}
body{margin:0;background:var(--bg);color:var(--text);display:flex;flex-direction:column;
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;font-size:16px;line-height:1.6}
header{display:flex;align-items:center;gap:14px;flex-wrap:wrap;padding:10px 16px;border-bottom:1px solid var(--border)}
.brand{font-weight:800;font-size:18px;letter-spacing:-.02em;color:var(--text);text-decoration:none}
.brand span{color:var(--accent)}
.crumb{color:var(--muted);font-size:14px}
.crumb a{color:var(--link);text-decoration:none}
.spacer{flex:1}
.progress{font-size:13px;font-weight:700;color:var(--accent);background:var(--accent-soft);padding:3px 10px;border-radius:999px}
button,.button{font:inherit;font-size:15px;cursor:pointer;border-radius:8px;border:1px solid var(--border);background:var(--surface);
  color:var(--text);padding:6px 14px;text-decoration:none;display:inline-block}
button:hover,.button:hover{border-color:var(--accent)}
button:disabled{opacity:.4;cursor:default;border-color:var(--border)}
.primary{background:var(--accent);border-color:var(--accent);color:var(--on-accent);font-weight:600}
main{flex:1;display:grid;grid-template-columns:clamp(360px,42vw,560px) minmax(0,1fr);min-height:0}
aside{display:flex;flex-direction:column;min-height:0;border-right:1px solid var(--border)}
#steps{display:grid;grid-template-columns:repeat(auto-fill,minmax(min(100%,230px),1fr));gap:8px 18px;padding:10px 20px 12px;border-bottom:1px solid var(--border)}
.part-name{font-size:11px;font-weight:700;letter-spacing:.05em;text-transform:uppercase;color:var(--muted);margin-bottom:4px}
.dots{display:flex;gap:6px;flex-wrap:wrap}
.dot{width:30px;height:30px;padding:0;border-radius:50%;font-size:13px;font-weight:700;color:var(--muted)}
.dot.done{background:var(--ok-soft);border-color:var(--ok);color:var(--ok)}
.dot.current{border:2px solid var(--accent);color:var(--accent)}
#lesson{flex:1;overflow-y:auto;padding:18px 24px 28px}
.step-meta{font-size:13px;font-weight:700;letter-spacing:.04em;text-transform:uppercase;color:var(--muted)}
#lesson h1{font-size:26px;letter-spacing:-.01em;line-height:1.2;margin:4px 0 2px}
.goal{color:var(--muted);margin:0 0 18px}
#lesson p{margin:0 0 14px}
#lesson ul{margin:0 0 14px;padding-left:22px}
#lesson li{margin:4px 0}
code{background:var(--code-bg);padding:.1em .38em;border-radius:5px;font-size:.88em;
  font-family:"SF Mono",ui-monospace,Menlo,Consolas,monospace;white-space:nowrap}
code.long{white-space:pre-wrap}
.box{border-left:4px solid var(--accent);background:var(--accent-soft);border-radius:0 10px 10px 0;padding:10px 14px;margin:0 0 16px}
.box-title{font-weight:700;margin-bottom:2px}
.box p{margin:0!important}
.try{background:var(--try-bg);border:1px solid var(--try-border);border-radius:12px;padding:12px 14px;margin:0 0 18px}
.try-title{font-size:13px;font-weight:700;letter-spacing:.04em;text-transform:uppercase;color:var(--try-accent);margin-bottom:8px}
.try-row + .try-row{border-top:1px dashed var(--try-border);margin-top:10px;padding-top:10px}
.cmd{display:flex;align-items:flex-start;gap:8px}
.cmd code{flex:1;min-width:0;overflow-wrap:anywhere;font-size:15px;padding:6px 10px;background:var(--term);color:#e8e8eb;border-radius:8px;white-space:pre-wrap}
.copy{flex-shrink:0;font-size:13px;padding:4px 10px}
.say{margin:6px 0 0!important}
.out-label{font-size:13px;color:var(--muted);margin-top:6px}
pre.out{margin:4px 0 0;background:var(--surface);border:1px solid var(--border);border-radius:8px;padding:8px 10px;
  font-family:"SF Mono",ui-monospace,Menlo,Consolas,monospace;font-size:13px;white-space:pre-wrap;overflow-x:auto}
.task{border:2px solid var(--accent);border-radius:12px;padding:14px 16px;margin:6px 0 18px;background:var(--surface)}
.task.solved{border-color:var(--ok);background:var(--ok-soft)}
.task-title{font-weight:800;color:var(--accent);margin-bottom:6px}
.task.solved .task-title{color:var(--ok)}
.answer{display:flex;gap:8px}
.answer input{flex:1;min-width:0;font:inherit;font-family:"SF Mono",ui-monospace,Menlo,Consolas,monospace;font-size:14px;
  padding:8px 10px;border-radius:8px;border:1px solid var(--border);background:var(--bg);color:var(--text)}
.answer input:focus{outline:2px solid var(--accent);outline-offset:-1px}
.msg{font-size:14px;margin-top:8px}
.msg:empty{display:none}
.msg.bad{color:var(--bad)}
.uses{margin:0 0 12px;font-size:15px;background:var(--bg);border:1px solid var(--border);border-radius:8px}
.uses-title{display:flex;align-items:center;gap:8px;padding:9px 12px;font-size:14px;font-weight:600;color:var(--text);cursor:pointer;list-style:none;user-select:none;border-radius:8px}
.uses-title:hover{background:var(--accent-soft)}
.uses-title:focus-visible{outline:2px solid var(--link);outline-offset:2px}
.uses-title::-webkit-details-marker{display:none}
.uses-title span{flex:1}
.uses-icon,.uses-chevron{width:18px;height:18px;fill:none;stroke:currentColor;stroke-width:2;stroke-linecap:round;stroke-linejoin:round}
.uses-icon{color:var(--accent)}
.uses-chevron{color:var(--muted);transition:transform .15s}
.uses[open] .uses-chevron{transform:rotate(180deg)}
.uses[open] .uses-title{border-radius:8px 8px 0 0}
#lesson .uses[open] ul{padding:2px 12px 10px 34px!important}
#lesson .uses ul{margin:0;padding-left:18px}
#lesson .uses li{margin:2px 0}
.hints{margin:0 0 12px;padding-left:0;list-style:none}
.hints li{background:var(--bg);border:1px solid var(--border);border-radius:8px;padding:6px 10px;margin:6px 0;font-size:15px}
.hint-n{font-size:12px;font-weight:700;color:var(--muted);text-transform:uppercase;margin-right:4px}
.hintbtn{margin-top:10px;font-size:14px;background:none;border-color:transparent;color:var(--link);padding:2px 0}
.done-msg{margin:0!important}
.skip{color:var(--muted)}
#lesson h2{font-size:19px;margin:22px 0 10px}
.chip{font-size:13px;font-weight:700;padding:3px 10px;border-radius:999px}
a.chip{color:var(--muted);text-decoration:none;border:1px solid var(--border)}
a.chip:hover{color:var(--text)}
.danger{color:var(--bad)}
.danger:hover{border-color:var(--bad)}
.cheatsheet{border:1px solid var(--border);border-radius:12px;padding:12px 16px;margin:0 0 16px;background:var(--surface)}
.cheatsheet ul{margin:0 0 10px!important}
.cheatsheet ul.groups{list-style:none;padding:0}
.cs-group{margin:0 0 16px}
.cs-title{font-weight:600}
.cs-note{color:var(--muted);margin:2px 0 6px}
.cs-cmd{display:block;margin:2px 0 8px;padding:6px 10px;background:var(--term);color:#e8e8eb;border-radius:8px;font-size:13px;white-space:pre-wrap}
.cs-cmd span,code.long span{white-space:nowrap}
.cs-cmd span.break,code.long span.break{white-space:normal;overflow-wrap:anywhere}
.cs-say{margin:6px 0 0;font-size:.92em}
.load-error{max-width:380px;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,sans-serif;font-size:15px;line-height:1.5}
.load-error p{color:#a1a1aa;margin:6px 0 14px}
.load-error a:not(.button){color:#22a861}
.load-error .notify input{background:#0b0b0c;border-color:#3f3f46;color:#e8e8eb}
.phone form{display:flex;flex-direction:column;gap:8px;margin:0 0 6px}
.phone input{padding:10px 12px;font:inherit;font-size:16px;background:#0b0b0c;border:1px solid #3f3f46;border-radius:8px;color:#e8e8eb}
.phone form button,.phone .here{padding:10px 16px;font:inherit;font-weight:700;border-radius:8px}
.phone .here{background:none;border:1px solid #3f3f46;color:#e8e8eb}
.phone [role=status]{margin:0;color:#f87171}
.phone [role=status]:empty{display:none}
.phone .fine{font-size:13px;margin:0 0 18px}
@media print{
  header,#steps,.term-wrap,.step-nav,.print,  body,main,aside,#lesson{display:block;height:auto;overflow:visible;border:none}
  .cheatsheet{border:none;padding:0}
  .cs-cmd{background:none;color:#000;border:1px solid #bbb}
  .cs-group{break-inside:avoid}
}
.step-nav{display:flex;justify-content:space-between;align-items:center;margin-top:8px;padding-top:14px;border-top:1px solid var(--border)}
.term-wrap{position:relative;background:var(--term);min-height:0;padding:10px}
#terminal{height:100%}
#overlay{position:absolute;inset:0;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:10px;
  background:var(--term);color:#e8e8eb;font-family:"SF Mono",ui-monospace,Menlo,Consolas,monospace;font-size:14px;text-align:center;padding:20px}
#overlay .bar{width:260px;height:6px;background:#27272b;border-radius:3px;overflow:hidden}
#overlay .bar div{height:100%;width:0;background:#22a861;transition:width .2s}
#overlay.hidden{display:none}
@media (max-width: 820px){
  /* Stack: lesson, then a terminal sized to the screen. The page scrolls. */
  html,body{overflow:visible}
  body{display:block;height:auto}
  main{display:block}
  aside{border-right:none;border-bottom:1px solid var(--border)}
  #lesson{overflow:visible}
  .term-wrap{height:70vh;overflow:hidden}
  header{gap:8px 10px}
  header button{font-size:13px;padding:4px 10px}
  .crumb{display:none}
  .wide{display:none}
}
.lab-tabs{display:flex;gap:8px;padding:8px;background:var(--surface)}
.lab-tabs [aria-selected="true"]{color:var(--accent);font-weight:bold}
/* The moderator's hidden browser surfaces its alerts here, as a log of lines. */
.moderator-notice{display:block;margin:0 8px 8px;padding:8px 12px;background:var(--surface);border:1px solid var(--border, #444);border-radius:6px;white-space:pre-wrap;overflow-wrap:anywhere;font-size:13px;user-select:text}
.moderator-notice[hidden]{display:none}
/* Tabs on top, then the terminal or the browser filling the rest, so neither overlaps the tabs. */
.term-wrap.has-preview{display:flex;flex-direction:column;gap:8px}
.browser-pane{flex:1;min-height:0;background:#fff;color:#111;display:flex;flex-direction:column;border-radius:6px;overflow:hidden}
.browser-pane[hidden],#terminal[hidden]{display:none}
.browser-address{display:flex;gap:8px;padding:12px}
.browser-address label{flex:1;display:flex;gap:8px;align-items:center}
.browser-address input{flex:1;min-width:0;color:#111;background:white}
.browser-pane iframe{width:100%;flex:1;border:0;background:white}
.browser-status{font-size:12px;padding:0 12px;margin:4px}
/* A page's alert(), drawn over the page like a browser's message box. */
.browser-pane{position:relative}
.browser-alert{position:absolute;top:64px;left:50%;transform:translateX(-50%);width:min(420px,calc(100% - 32px));box-sizing:border-box;background:#fff;color:#111;border:1px solid #ccc;border-radius:10px;box-shadow:0 8px 28px rgba(0,0,0,.25);padding:14px 16px;z-index:2}
.browser-alert[hidden]{display:none}
.browser-alert p{margin:0 0 12px;font-size:14px}
.browser-alert-from{font-weight:600}
.browser-alert-text{white-space:pre-wrap;overflow-wrap:anywhere;user-select:text}
.browser-alert button{display:block;margin-left:auto;background:#1a73e8;color:#fff;border-color:#1a73e8;padding:4px 18px}

.term-wrap.has-preview #terminal{flex:1;min-height:0;height:auto}