/* Styles for the Python coding games. Loaded only on /python-coding-games/ pages. */

/* ---------- hub grid ---------- */
.gamegrid{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}
a.gamecard{display:flex;flex-direction:column;background:var(--bg);border:1px solid var(--line);border-radius:18px;padding:26px 24px 22px;color:inherit;transition:transform .18s,box-shadow .18s,border-color .18s}
a.gamecard:hover{text-decoration:none;transform:translateY(-3px);box-shadow:0 18px 34px rgba(15,28,46,.1);border-color:var(--blue)}
.gamecard .gic{width:58px;height:58px;border-radius:16px;display:flex;align-items:center;justify-content:center;font-size:30px;margin-bottom:16px}
.gamecard h3{margin:0 0 6px;font-size:21px}
.gamecard .tagline{font-family:var(--head);font-weight:600;color:var(--blue);font-size:14.5px;margin:0 0 10px}
.gamecard p{font-size:15px;margin:0 0 16px}
.gamecard .chips{display:flex;flex-wrap:wrap;gap:6px;margin-bottom:16px}
.gamecard .chips span{font-size:12.5px;background:var(--surface);border:1px solid var(--line);border-radius:999px;padding:3px 10px;color:var(--muted)}
.gamecard .meta2{margin-top:auto;display:flex;gap:14px;flex-wrap:wrap;font-size:13px;color:var(--muted);border-top:1px solid var(--line);padding-top:14px}
.gamecard .play{display:inline-flex;align-items:center;gap:7px;margin-top:14px;font-family:var(--head);font-weight:700;color:var(--blue)}

/* ---------- shared game shell ---------- */
.gamewrap{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:26px;align-items:start}
.gamewrap>*{min-width:0;max-width:100%}
.panel,.editor,.keys,.console,.boardwrap{min-width:0;max-width:100%}
.editor textarea{width:100%}
.panel{background:var(--bg);border:1px solid var(--line);border-radius:16px;overflow:hidden}
.panel-h{display:flex;align-items:center;gap:10px;justify-content:space-between;padding:12px 16px;border-bottom:1px solid var(--line);background:var(--surface)}
.panel-h b{font-family:var(--head);font-size:15px;color:var(--ink)}
.panel-b{padding:16px}
.levels{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:18px}
.levels button{font-family:var(--head);font-weight:700;font-size:14px;min-width:42px;padding:8px 12px;border-radius:10px;border:1px solid var(--line);background:var(--bg);color:var(--body);cursor:pointer}
.levels button:hover{border-color:var(--blue);color:var(--blue)}
.levels button.on{background:var(--blue);border-color:var(--blue);color:#fff}
.levels button.done::after{content:" ✓";color:var(--green)}
.levels button.on.done::after{color:#cdf5e4}
.brief{font-size:15.5px;margin:0 0 14px}
.brief code,.hintbox code{background:var(--blue-l);color:var(--blue-d);padding:1px 5px;border-radius:5px;font-family:var(--mono);font-size:.9em}
.hintbox{display:none;background:#fffbe6;border-left:4px solid var(--yellow);border-radius:0 10px 10px 0;padding:12px 16px;font-size:15px;margin:0 0 14px}
.hintbox.show{display:block}
.gbar{display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin-top:14px}
.gbtn{font-family:var(--head);font-weight:700;font-size:15px;padding:11px 20px;border-radius:999px;border:0;cursor:pointer;background:var(--blue);color:#fff;display:inline-flex;align-items:center;gap:8px}
.gbtn:hover{background:var(--blue-d)}
.gbtn[disabled]{opacity:.55;cursor:progress}
.gbtn.sec{background:transparent;color:var(--blue);border:2px solid var(--blue-l)}
.gbtn.sec:hover{background:var(--blue-l)}
.gbtn.tiny{font-size:13.5px;padding:7px 14px}

/* ---------- editor ---------- */
.editor{position:relative;display:flex;background:var(--code-bg);border-radius:12px;overflow:hidden;font-family:var(--mono);font-size:13.5px;line-height:1.55}
.editor .gutter{padding:14px 8px 14px 14px;color:#56657c;text-align:right;user-select:none;white-space:pre;background:rgba(255,255,255,.03)}
.editor textarea{flex:1;min-width:0;background:transparent;color:var(--code-ink);border:0;outline:none;resize:vertical;padding:14px 14px 14px 10px;font:inherit;line-height:inherit;tab-size:4;min-height:230px;white-space:pre;overflow-wrap:normal;overflow-x:auto}
.keys{display:flex;gap:6px;overflow-x:auto;padding:8px 0 2px;-webkit-overflow-scrolling:touch}
.keys button{flex:none;font-family:var(--mono);font-size:14px;min-width:34px;height:34px;border-radius:8px;border:1px solid var(--line);background:var(--surface);color:var(--ink);cursor:pointer}
.keys button:active{background:var(--blue-l)}
.console{background:var(--code-bg);color:#b8c4d6;border-radius:12px;padding:12px 14px;font-family:var(--mono);font-size:13px;white-space:pre-wrap;min-height:48px;margin-top:14px;max-height:190px;overflow:auto}
.console .ok{color:#8fd694}.console .bad{color:#ff8e8e}.console .dim{color:#7d8590}

/* ---------- maze board ---------- */
.boardwrap{position:relative;display:flex;justify-content:center;overflow:hidden}
canvas.board{display:block;max-width:100%;border-radius:14px;background:#0b1222;transition:box-shadow .2s}
canvas.board.running{box-shadow:0 0 0 2px rgba(53,114,165,.5),0 0 28px rgba(53,114,165,.4)}
.cell{width:var(--cell);height:var(--cell);border-radius:6px;background:#17263a}
.cell.wall{background:#0a111c;box-shadow:inset 0 0 0 1px #16233a}
.cell.goal{background:#15402f;box-shadow:inset 0 0 0 2px #22a06b}
.cell.goal::after{content:"🏁";font-size:calc(var(--cell) * .6);display:flex;align-items:center;justify-content:center;height:100%}
.cell.gem::after{content:"💎";font-size:calc(var(--cell) * .58);display:flex;align-items:center;justify-content:center;height:100%}
.robot{position:absolute;width:var(--cell);height:var(--cell);display:flex;align-items:center;justify-content:center;font-size:calc(var(--cell) * .68);transition:left .14s linear,top .14s linear,transform .14s linear;will-change:left,top,transform}
.robot.crash{animation:shake .3s}
@keyframes shake{0%,100%{margin-left:0}25%{margin-left:-5px}75%{margin-left:5px}}
.stats{display:flex;gap:18px;flex-wrap:wrap;font-size:14px;color:var(--muted);margin-top:12px;justify-content:center}
.stats b{font-family:var(--head);color:var(--ink)}
.apilist{font-size:14.5px;margin:0}
.apilist dt{font-family:var(--mono);font-size:13.5px;color:var(--blue-d);background:var(--blue-l);display:inline-block;padding:2px 7px;border-radius:6px;margin-top:10px}
.apilist dd{margin:4px 0 0;color:var(--body)}
details.api summary{cursor:pointer;font-family:var(--head);font-weight:700;color:var(--ink);padding:6px 0}

/* ---------- win overlay ---------- */
.overlay{position:fixed;inset:0;background:rgba(10,18,32,.72);display:none;align-items:center;justify-content:center;padding:20px;z-index:80}
.overlay.show{display:flex}
.overlay .box{background:var(--bg);border-radius:20px;padding:32px 28px;max-width:420px;width:100%;text-align:center;box-shadow:0 30px 60px rgba(0,0,0,.3)}
.overlay h3{margin:0 0 8px;font-size:26px}
.overlay p{margin:0 0 18px}
.overlay .big{font-size:52px;line-height:1;margin-bottom:10px}

/* ---------- quiz ---------- */
.quiz{max-width:720px;margin:0 auto}
.qtop{display:flex;justify-content:space-between;align-items:center;gap:14px;flex-wrap:wrap;margin-bottom:14px;font-family:var(--head);font-weight:700;color:var(--ink)}
.qtop .lives{letter-spacing:2px}
.qtop .streak{color:var(--orange)}
.timerbar{height:8px;border-radius:99px;background:var(--line);overflow:hidden;margin-bottom:18px}
.timerbar i{display:block;height:100%;width:100%;background:var(--blue);transition:width .2s linear}
.timerbar.warn i{background:#e5484d}
.qcode{background:var(--code-bg);color:var(--code-ink);border-radius:12px;padding:18px 20px;font-family:var(--mono);font-size:14.5px;line-height:1.6;white-space:pre;overflow-x:auto;margin:0 0 18px}
.opts{display:grid;grid-template-columns:1fr 1fr;gap:12px}
.opts button{text-align:left;font-family:var(--mono);font-size:14.5px;padding:14px 16px;border-radius:12px;border:2px solid var(--line);background:var(--bg);color:var(--ink);cursor:pointer;transition:border-color .15s,background .15s;word-break:break-word}
.opts button:hover:not([disabled]){border-color:var(--blue);background:var(--blue-l)}
.opts button.right{border-color:var(--green);background:#e9f8f1}
.opts button.wrong{border-color:#e5484d;background:#fdecec}
.opts button[disabled]{cursor:default}
.explain{display:none;margin-top:18px;padding:16px 18px;border-radius:12px;background:var(--surface);border-left:4px solid var(--blue);font-size:15.5px}
.explain.show{display:block}
.explain b{font-family:var(--head);color:var(--ink);display:block;margin-bottom:4px}
.qstart{text-align:center;padding:10px 0 4px}
.qstart .big{font-size:60px;margin-bottom:6px}
.scoreline{display:flex;gap:26px;justify-content:center;margin:22px 0}
.scoreline div{text-align:center}
.scoreline b{display:block;font-family:var(--head);font-size:30px;color:var(--ink)}
.scoreline span{font-size:13px;color:var(--muted)}

/* ---------- bug squash ---------- */
.tests{list-style:none;padding:0;margin:0;font-size:14.5px}
.tests li{display:flex;gap:10px;align-items:flex-start;padding:9px 0;border-bottom:1px solid var(--line)}
.tests li:last-child{border-bottom:0}
.tests .mark{flex:none;width:22px;height:22px;border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:13px;background:var(--surface);color:var(--muted)}
.tests li.pass .mark{background:#dff7ea;color:#14804a}
.tests li.fail .mark{background:#fdecec;color:#c62f32}
.tests code{font-family:var(--mono);font-size:13px;color:var(--body);background:none;padding:0}
.tests .why{display:block;color:#c62f32;font-size:13px;margin-top:3px}
.bugmeta{display:flex;gap:10px;flex-wrap:wrap;margin-bottom:12px}
.bugmeta span{font-size:12.5px;background:var(--surface);border:1px solid var(--line);border-radius:999px;padding:3px 10px;color:var(--muted)}

/* ---------- app CTA inside games ---------- */
.gcta{display:flex;gap:16px;align-items:center;background:var(--blue-l);border-radius:14px;padding:16px 18px;margin-top:24px;font-size:15px}
.gcta img{width:46px;height:46px;border-radius:11px;flex:none}
.gcta .btn{flex:none}

@media(max-width:900px){
  .gamegrid{grid-template-columns:1fr}
  .gamewrap{grid-template-columns:minmax(0,1fr)}
  .opts{grid-template-columns:1fr}
  .board{--cell:30px}
  .editor textarea{min-height:190px}
  .gcta{flex-direction:column;align-items:flex-start}
}
@media(max-width:900px){
  /* the comparison tables scroll instead of widening the page */
  .prose table{display:block;overflow-x:auto;max-width:100%}
}
@media(max-width:400px){.board{--cell:26px}}

/* ======================= game feel: effects & animation ======================= */
.confetti{position:absolute;inset:0;pointer-events:none;z-index:5}
.floater{position:absolute;left:50%;top:40%;transform:translate(-50%,0);font-family:var(--head);font-weight:800;
  font-size:20px;color:var(--yellow-d);text-shadow:0 2px 6px rgba(0,0,0,.35);pointer-events:none;animation:floatUp .9s ease-out forwards;z-index:6}
.floater.gem{color:#ffd43b}
@keyframes floatUp{0%{opacity:0;transform:translate(-50%,10px) scale(.7)}20%{opacity:1}100%{opacity:0;transform:translate(-50%,-46px) scale(1.15)}}

/* sound toggle */
.sfxtoggle{margin-left:auto;display:inline-flex;align-items:center;gap:7px;height:40px;padding:0 14px;border-radius:999px;
  border:1px solid var(--line);background:var(--bg);color:var(--body);font-family:var(--head);font-weight:700;font-size:14px;
  line-height:1;cursor:pointer;flex:none;transition:transform .12s,border-color .15s,color .15s}
.sfxtoggle svg{width:18px;height:18px;flex:none}
.sfxtoggle[aria-pressed="false"]{color:var(--muted)}
.sfxtoggle[aria-pressed="true"]{color:var(--blue);border-color:var(--blue-l);background:var(--blue-l)}
.quiz .panel-b{position:relative}
@media(max-width:480px){.sfxtoggle span{display:none}.sfxtoggle{padding:0 12px}}
.sfxtoggle:hover{border-color:var(--blue);transform:scale(1.06)}
.sfxtoggle:active{transform:scale(.94)}
.levels{align-items:center}

/* buttons get some bounce */
.gbtn{transition:transform .12s,background .15s,box-shadow .15s}
.gbtn:active{transform:scale(.95)}
.gbtn.go{box-shadow:0 0 0 0 rgba(53,114,165,.5);animation:readyPulse 2.4s ease-out infinite}
@keyframes readyPulse{0%{box-shadow:0 0 0 0 rgba(53,114,165,.45)}70%{box-shadow:0 0 0 14px rgba(53,114,165,0)}100%{box-shadow:0 0 0 0 rgba(53,114,165,0)}}

/* ---- maze ---- */
.board{position:relative;transition:box-shadow .2s}
.board.running{box-shadow:0 0 0 2px rgba(53,114,165,.5),0 0 26px rgba(53,114,165,.35)}
.cell{transition:background .25s,box-shadow .25s}
.cell.trail{background:#1d3350;box-shadow:inset 0 0 0 1px rgba(53,114,165,.45)}
.cell.goal{animation:goalGlow 2.2s ease-in-out infinite}
@keyframes goalGlow{0%,100%{box-shadow:inset 0 0 0 2px #22a06b}50%{box-shadow:inset 0 0 0 2px #35d99a,0 0 16px rgba(34,160,107,.6)}}
.cell.gem::after{animation:gemBob 1.6s ease-in-out infinite}
@keyframes gemBob{0%,100%{transform:translateY(0) scale(1)}50%{transform:translateY(-3px) scale(1.08)}}
.cell.popped{animation:cellPop .4s ease-out}
@keyframes cellPop{0%{background:#2b6cb0}100%{background:#17263a}}
.robot{z-index:4;filter:drop-shadow(0 3px 5px rgba(0,0,0,.5))}
.robot.step{animation:hop .16s ease-out}
@keyframes hop{0%{transform-origin:center;scale:1}50%{scale:1.18}100%{scale:1}}
.robot.cheer{animation:cheer .6s ease-out 2}
@keyframes cheer{0%,100%{translate:0 0}30%{translate:0 -8px}60%{translate:0 0}}
.board.shake{animation:boardShake .36s}
@keyframes boardShake{0%,100%{transform:translateX(0)}20%{transform:translateX(-7px)}40%{transform:translateX(6px)}60%{transform:translateX(-4px)}80%{transform:translateX(3px)}}

/* ---- quiz ---- */
.opts button{transition:border-color .15s,background .15s,transform .12s}
.opts button:active:not([disabled]){transform:scale(.98)}
.opts button.right{animation:rightPop .45s ease-out}
@keyframes rightPop{0%{transform:scale(1)}40%{transform:scale(1.04)}100%{transform:scale(1)}}
.opts button.wrong{animation:wrongShake .35s}
@keyframes wrongShake{0%,100%{transform:translateX(0)}25%{transform:translateX(-6px)}50%{transform:translateX(6px)}75%{transform:translateX(-3px)}}
.timerbar.warn i{animation:timerFlash .5s steps(2,end) infinite}
@keyframes timerFlash{0%{opacity:1}100%{opacity:.55}}
.qtop .lives{transition:transform .2s}
.qtop .lives.hit{animation:heartHit .45s ease-out}
@keyframes heartHit{0%{transform:scale(1)}35%{transform:scale(1.3) rotate(-6deg)}100%{transform:scale(1)}}
.qtop .streak{display:inline-block;animation:flame .8s ease-in-out infinite alternate}
@keyframes flame{from{transform:scale(1)}to{transform:scale(1.12)}}
.qcode{animation:cardIn .3s ease-out}
@keyframes cardIn{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:none}}

/* ---- bug squash ---- */
.tests li{transition:background .25s}
.tests li.pass{animation:passSweep .5s ease-out}
@keyframes passSweep{0%{background:#dff7ea}100%{background:transparent}}
.tests li.fail .mark{animation:wrongShake .35s}
.tests li.reveal{animation:rowIn .3s ease-out backwards}
@keyframes rowIn{from{opacity:0;transform:translateX(-10px)}to{opacity:1;transform:none}}
.splat{animation:splat .5s ease-out}
@keyframes splat{0%{transform:scale(.4) rotate(-20deg);opacity:0}60%{transform:scale(1.25) rotate(8deg);opacity:1}100%{transform:scale(1) rotate(0);opacity:1}}

/* ---- win overlay ---- */
.overlay .box{position:relative;overflow:hidden;animation:boxIn .34s cubic-bezier(.2,1.3,.4,1)}
@keyframes boxIn{from{opacity:0;transform:translateY(26px) scale(.92)}to{opacity:1;transform:none}}
.overlay .big{animation:bigPop .5s cubic-bezier(.2,1.5,.4,1)}
@keyframes bigPop{0%{transform:scale(.2) rotate(-25deg);opacity:0}70%{transform:scale(1.2) rotate(6deg)}100%{transform:scale(1) rotate(0);opacity:1}}

@media(prefers-reduced-motion:reduce){
  *,*::before,*::after{animation:none!important;transition:none!important}
}

/* ======================= turtle art ======================= */
.canvaswrap{display:flex;justify-content:center}
#canvas{border-radius:12px;background:#0d1520;max-width:100%;transition:box-shadow .2s}
#canvas.running{box-shadow:0 0 0 2px rgba(53,114,165,.5),0 0 26px rgba(53,114,165,.35)}
.legend{display:flex;gap:18px;justify-content:center;flex-wrap:wrap;font-size:13.5px;color:var(--muted);margin-top:12px}
.legend i{display:inline-block;width:22px;height:4px;border-radius:2px;vertical-align:middle;margin-right:7px}
.legend .t{background:rgba(120,140,170,.55)}
.legend .y{background:var(--blue)}

/* ======================= code scramble ======================= */
.lines{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:6px}
.sline{display:flex;align-items:center;gap:10px;background:var(--code-bg);border-radius:10px;
  padding:9px 12px;cursor:grab;user-select:none;border-color:#22314a;transition:border-color .15s,transform .12s,background .2s}
.sline:hover{border-color:var(--blue)}
.sline:focus-visible{outline:2px solid var(--blue);outline-offset:2px}
.sline.dragging{opacity:.45;cursor:grabbing}
.sline.over{border-color:var(--yellow);transform:translateY(2px)}
.sline .grip{color:#56657c;font-size:15px;flex:none;letter-spacing:-2px}
.sline .num{color:#56657c;font-family:var(--mono);font-size:12px;width:18px;text-align:right;flex:none}
.sline code{font-family:var(--mono);font-size:13.5px;color:var(--code-ink);background:none;padding:0;border-radius:0;white-space:pre;overflow-x:auto;flex:1;min-width:0}
.sline code.in1{padding-left:26px}.sline code.in2{padding-left:52px}.sline code.in3{padding-left:78px}
.sline .arrows{display:flex;flex-direction:column;gap:2px;flex:none}
.sline .arrows button{width:26px;height:18px;line-height:1;font-size:9px;border:1px solid #2b3b56;background:#16233a;color:#9fb3cd;border-radius:5px;cursor:pointer;padding:0}
.sline .arrows button:hover{background:var(--blue);color:#fff;border-color:var(--blue)}
.sline.good{border-color:var(--green);background:#10261f;animation:rowIn .35s ease-out backwards}
.sline.badline{animation:wrongShake .35s;border-color:#e5484d}
.outbox{background:var(--code-bg);color:#b8c4d6;border-radius:12px;padding:12px 14px;font-family:var(--mono);
  font-size:13px;white-space:pre-wrap;margin-top:14px;min-height:54px}
.outbox b{display:block;font-family:var(--sans);font-size:11px;letter-spacing:.08em;text-transform:uppercase;color:var(--green);margin-bottom:4px}
.outbox .dim{color:#7d8590}
.movebox{font-size:14px;color:var(--muted)}
.movebox b{font-family:var(--head);color:var(--ink)}

/* ======================= code golf ======================= */
.meter{margin:14px 0 4px}
.meterline{display:flex;justify-content:space-between;font-size:13.5px;color:var(--muted);margin-bottom:6px}
.meterline b{font-family:var(--head);color:var(--ink);font-size:16px}
.metertrack{height:10px;border-radius:99px;background:var(--line);overflow:hidden}
.metertrack i{display:block;height:100%;width:0;background:#e5484d;border-radius:99px;transition:width .25s ease}
.metertrack i.mid{background:var(--orange)}
.metertrack i.ok{background:var(--green)}
#verdict{font-family:var(--head);font-weight:700;color:var(--ink)}

@media(max-width:900px){
  .sline .grip{display:none}
  .sline code{font-size:12.5px}
}

/* ---------- concept games (one game per Python topic) ---------- */
.ctop{display:flex;align-items:center;gap:12px;flex-wrap:wrap;margin-bottom:18px}
.ctop .levels{margin-bottom:0;flex:1}
.ctop .prog{font-size:13.5px;color:var(--muted);font-family:var(--head);font-weight:700;white-space:nowrap}
.tests li.reveal{animation:popin .22s ease-out both}
@keyframes popin{from{opacity:0;transform:translateY(5px)}to{opacity:1;transform:none}}
.tests li>div{font-size:14.5px;color:var(--body)}

/* shared visualiser frame */
.vis{background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:14px;margin-bottom:14px;overflow-x:auto}
.viswait{margin:0;font-size:14px;color:var(--muted);text-align:center;padding:8px 0}

/* value boxes */
.vrow{display:flex;flex-wrap:wrap;gap:10px}
.vbox{display:flex;flex-direction:column;gap:2px;background:var(--bg);border:1px solid var(--line);border-radius:10px;padding:9px 13px;min-width:92px}
.vbox.empty{opacity:.55;border-style:dashed}
.vbox .vname{font-family:var(--mono);font-size:12px;color:var(--blue-d)}
.vbox .vval{font-family:var(--mono);font-size:15px;color:var(--ink);word-break:break-all}
.vbox .vtype{font-size:11px;color:var(--muted);text-transform:lowercase}

/* scoreboard / case table */
table.vtable{width:100%;border-collapse:collapse;font-size:14px}
table.vtable th{text-align:left;font-family:var(--head);font-size:12.5px;text-transform:uppercase;letter-spacing:.05em;color:var(--muted);padding:0 10px 7px 0;border-bottom:1px solid var(--line)}
table.vtable td{padding:7px 10px 7px 0;border-bottom:1px solid var(--line);font-family:var(--mono);font-size:13.5px;color:var(--body)}
table.vtable tr:last-child td{border-bottom:0}
table.vtable td.want{color:var(--blue-d)}
table.vtable td.mk{width:24px;text-align:right;font-family:var(--head);font-weight:700}
table.vtable tr.hit td.mk{color:var(--green)}
table.vtable tr.miss td.mk{color:#c62f32}
table.vtable tr.hit td.got{color:var(--green)}
table.vtable tr.miss td.got{color:#c62f32}
table.vtable code{background:none;padding:0;font-size:13.5px}

/* string index ruler */
.ruler{display:inline-block;min-width:100%;margin-bottom:12px}
.ruler .row{display:flex;gap:3px}
.ruler .ch,.ruler .ix{flex:none;width:30px;text-align:center;font-family:var(--mono)}
.ruler .ch{font-size:17px;color:var(--ink);background:var(--bg);border:1px solid var(--line);border-radius:7px;padding:7px 0;margin-bottom:5px}
.ruler .ix{font-size:11px;color:var(--muted);padding:1px 0}
.ruler .ix.neg{color:var(--orange)}

/* conveyor belt of printed lines */
.belt{display:flex;flex-wrap:wrap;gap:8px}
.belt .item{font-family:var(--mono);font-size:13.5px;background:var(--bg);border:1px solid var(--line);border-left:4px solid var(--blue);border-radius:8px;padding:7px 12px;animation:slidein .3s ease-out both}
.belt .item.hit{border-left-color:var(--green)}
.belt .item.miss{border-left-color:#c62f32;color:#c62f32}
@keyframes slidein{from{opacity:0;transform:translateX(-14px)}to{opacity:1;transform:none}}
@media(prefers-reduced-motion:reduce){.belt .item,.tests li.reveal{animation:none}}

/* concept section on the hub */
.conceptgrid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
a.conceptcard{display:flex;flex-direction:column;gap:6px;background:var(--bg);border:1px solid var(--line);border-radius:14px;padding:18px 18px 16px;color:inherit;transition:transform .16s,border-color .16s,box-shadow .16s}
a.conceptcard:hover{text-decoration:none;transform:translateY(-2px);border-color:var(--blue);box-shadow:0 14px 26px rgba(15,28,46,.09)}
a.conceptcard .cic{width:42px;height:42px;border-radius:12px;display:flex;align-items:center;justify-content:center;font-size:22px;margin-bottom:4px}
a.conceptcard h3{margin:0;font-size:18px}
a.conceptcard .topic{font-family:var(--head);font-weight:600;font-size:13px;color:var(--blue);text-transform:uppercase;letter-spacing:.05em}
a.conceptcard p{margin:0;font-size:14.5px}
a.conceptcard .lv{margin-top:auto;padding-top:12px;font-size:13px;color:var(--muted)}
@media(max-width:860px){.conceptgrid{grid-template-columns:repeat(2,1fr)}}
@media(max-width:560px){.conceptgrid{grid-template-columns:1fr}.ruler .ch,.ruler .ix{width:26px}}


/* =======================================================================
   ARCADE — the /python-coding-games/ hub only.
   A deliberately different environment from the rest of the site: dark,
   neon and loud, so arriving feels like walking into an arcade rather
   than turning a page. Everything is scoped under .arcade so no tutorial
   or game page inherits any of it, and it is pure CSS — no images, no
   extra scripts, nothing that costs a page-load metric.
   ======================================================================= */
.arcade{
  --n-blue:#4da3ff;--n-purple:#b57cff;--n-green:#3ddc97;--n-orange:#ffb43d;
  --n-cyan:#46e5ff;--n-dim:#9fb2d0;
  /* The game UIs are built from these tokens, so re-pointing them here themes
     every panel, button, badge and table at once. Far safer than overriding a
     hundred individual rules — and a new component is dark automatically. */
  --bg:#101a33;--surface:#15203d;--line:#27345a;
  --ink:#f2f7ff;--body:#b4c6e3;--muted:#8ba1c4;
  --blue:#4da3ff;--blue-d:#9fd0ff;--blue-l:rgba(77,163,255,.16);
  --green:#3ddc97;--orange:#ffb43d;--yellow-d:#ffd36e;
  position:relative;isolation:isolate;color:var(--n-dim);
  background:
    radial-gradient(900px 520px at 12% -6%,rgba(77,163,255,.20),transparent 62%),
    radial-gradient(760px 480px at 88% 2%,rgba(181,124,255,.20),transparent 60%),
    radial-gradient(680px 420px at 50% 100%,rgba(70,229,255,.10),transparent 65%),
    linear-gradient(180deg,#070b18 0%,#0a1024 45%,#080d1c 100%);
}
/* Static starfield, confined to the hero.

   This used to cover the whole (very tall) page and animate its
   background-position, which repainted an enormous area every single frame and
   made scrolling stutter. A static layer over the hero alone costs nothing and
   looks the same while you are reading it. */
.arcade .hero::before{
  content:"";position:absolute;inset:0;z-index:-1;pointer-events:none;opacity:.5;
  background-image:
    radial-gradient(1.6px 1.6px at 12% 18%,#fff,transparent),
    radial-gradient(1.4px 1.4px at 68% 11%,#bfe0ff,transparent),
    radial-gradient(1.8px 1.8px at 34% 62%,#fff,transparent),
    radial-gradient(1.3px 1.3px at 86% 48%,#d9c6ff,transparent),
    radial-gradient(1.5px 1.5px at 52% 86%,#fff,transparent),
    radial-gradient(1.3px 1.3px at 22% 92%,#aee9ff,transparent),
    radial-gradient(1.6px 1.6px at 94% 78%,#fff,transparent);
  background-size:620px 620px;
}

/* ---------- hero ---------- */
.arcade .hero{background:none;padding:54px 0 28px;position:relative}
.arcade .hero::after{            /* perspective grid floor */
  content:"";position:absolute;left:0;right:0;bottom:0;height:200px;z-index:-1;pointer-events:none;
  background-image:
    linear-gradient(rgba(77,163,255,.20) 1px,transparent 1px),
    linear-gradient(90deg,rgba(77,163,255,.20) 1px,transparent 1px);
  background-size:48px 48px;
  transform:perspective(320px) rotateX(66deg);transform-origin:bottom center;
  -webkit-mask-image:linear-gradient(transparent,#000 72%);
  mask-image:linear-gradient(transparent,#000 72%);
}
.arcade .hero .eyebrow{
  background:rgba(70,229,255,.10);color:var(--n-cyan);border:1px solid rgba(70,229,255,.45);
  box-shadow:0 0 22px rgba(70,229,255,.22);letter-spacing:.14em;
}
.arcade h1{
  color:#fff;font-size:clamp(38px,6vw,64px);line-height:1.03;letter-spacing:-.025em;
  background:linear-gradient(92deg,#ffffff 8%,#9ad0ff 40%,#c9a6ff 70%,#ffd36e 100%);
  -webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent;
}
.arcade .hero .lede{color:#b9c9e6;font-size:17.5px;max-width:730px}
.arcade .hero .lede strong{color:#fff}

/* ---------- buttons ---------- */
.arcade .btn{
  background:linear-gradient(180deg,#3f8dff,#2f6ae0);border:1px solid rgba(154,208,255,.5);color:#fff;
  box-shadow:0 10px 26px rgba(47,106,224,.40),0 0 24px rgba(77,163,255,.32);
  text-transform:uppercase;letter-spacing:.05em;font-size:14.5px;
}
.arcade .btn:hover{transform:translateY(-2px);box-shadow:0 14px 34px rgba(47,106,224,.55),0 0 38px rgba(77,163,255,.55)}
.arcade .btn.ghost{background:rgba(255,255,255,.05);border:1px solid rgba(154,208,255,.38);color:#cfe3ff;box-shadow:none}
.arcade .btn.ghost:hover{background:rgba(77,163,255,.14);border-color:var(--n-blue);box-shadow:0 0 26px rgba(77,163,255,.32)}
.arcade .btn.y{background:linear-gradient(180deg,#ffd95e,#f0b429);color:#2a1d00;border-color:rgba(255,230,150,.7);
  box-shadow:0 10px 26px rgba(240,180,41,.35),0 0 24px rgba(255,212,59,.35)}

/* ---------- section headings ---------- */
.arcade h2{color:#fff;letter-spacing:-.01em}
.arcade .seclabel{
  display:inline-flex;align-items:center;gap:9px;font-family:var(--head);font-weight:700;
  font-size:12px;letter-spacing:.2em;text-transform:uppercase;color:var(--n-cyan);margin-bottom:10px;
}
.arcade .seclabel::before{content:"";width:22px;height:2px;background:var(--n-cyan);box-shadow:0 0 10px var(--n-cyan)}
.arcade .secnote{color:#8fa3c4;max-width:720px;margin:0 0 22px}

/* ---------- cards: shared neon cabinet look ---------- */
.arcade a.conceptcard,.arcade a.gamecard{
  position:relative;overflow:hidden;color:#c9d8ef;
  background:linear-gradient(180deg,rgba(255,255,255,.065),rgba(255,255,255,.022));
  border:1px solid rgba(255,255,255,.11);border-radius:16px;
  box-shadow:0 10px 30px rgba(0,0,0,.35);
  transition:transform .18s,border-color .18s,box-shadow .18s;
}
.arcade a.conceptcard::before,.arcade a.gamecard::before{   /* neon strip along the top */
  content:"";position:absolute;top:0;left:0;right:0;height:2px;
  background:var(--accent,var(--n-blue));opacity:.75;transition:opacity .18s,box-shadow .18s;
}
.arcade a.conceptcard:hover,.arcade a.gamecard:hover{
  transform:translateY(-5px);border-color:var(--accent,var(--n-blue));
  box-shadow:0 18px 44px rgba(0,0,0,.5),0 0 34px color-mix(in srgb,var(--accent,#4da3ff) 38%,transparent);
}
.arcade a.conceptcard:hover::before,.arcade a.gamecard:hover::before{
  opacity:1;box-shadow:0 0 16px var(--accent,var(--n-blue));
}
.arcade a.conceptcard h3,.arcade a.gamecard h3{color:#fff}
.arcade a.gamecard p,.arcade a.conceptcard p{color:#9fb2d0}

/* per-card accent, driven by the existing colour letter */
.arcade .conceptcard:has(.ic.b),.arcade .gamecard:has(.ic.b){--accent:var(--n-blue)}
.arcade .conceptcard:has(.ic.p),.arcade .gamecard:has(.ic.p){--accent:var(--n-purple)}
.arcade .conceptcard:has(.ic.g),.arcade .gamecard:has(.ic.g){--accent:var(--n-green)}
.arcade .conceptcard:has(.ic.o),.arcade .gamecard:has(.ic.o){--accent:var(--n-orange)}

/* the emoji tile becomes a glowing badge */
.arcade .conceptcard .ic,.arcade .gamecard .ic{
  background:rgba(255,255,255,.06)!important;border:1px solid var(--accent,var(--n-blue));
  box-shadow:0 0 20px color-mix(in srgb,var(--accent,#4da3ff) 30%,transparent),
             inset 0 0 18px color-mix(in srgb,var(--accent,#4da3ff) 14%,transparent);
}
.arcade a.conceptcard:hover .ic,.arcade a.gamecard:hover .ic{
  box-shadow:0 0 30px color-mix(in srgb,var(--accent,#4da3ff) 55%,transparent),
             inset 0 0 20px color-mix(in srgb,var(--accent,#4da3ff) 22%,transparent);
}

/* concept card details */
.arcade a.conceptcard .topic{color:var(--accent,var(--n-blue));text-shadow:0 0 14px color-mix(in srgb,var(--accent,#4da3ff) 45%,transparent)}
.arcade a.conceptcard .lv{color:#7d93b5;border-top:1px solid rgba(255,255,255,.09);margin-top:auto}

/* challenge card details */
.arcade .gamecard .tagline{color:var(--accent,var(--n-blue))}
.arcade .gamecard .chips span{background:rgba(255,255,255,.05);border-color:rgba(255,255,255,.12);color:#9fb2d0}
.arcade .gamecard .meta2{border-top-color:rgba(255,255,255,.09);color:#7d93b5}
.arcade .gamecard .play{color:var(--accent,var(--n-blue))}
.arcade a.gamecard:hover .play{text-shadow:0 0 14px color-mix(in srgb,var(--accent,#4da3ff) 60%,transparent)}

/* ---------- long-form content, inverted ---------- */
.arcade section.alt{background:rgba(4,8,18,.5);border-top:1px solid rgba(255,255,255,.07)}
.arcade .prose{color:#aabdd9}
.arcade .prose h2,.arcade .prose h3{color:#fff}
.arcade .prose strong,.arcade .prose b{color:#e6eefb}
.arcade .prose a{color:#7cc0ff}
.arcade .prose a:hover{color:#a8d6ff}
.arcade .prose code{background:rgba(124,192,255,.12);color:#9fd0ff}
.arcade .prose th,.arcade .prose td{border-color:rgba(255,255,255,.11)}
.arcade .prose th{background:rgba(255,255,255,.05);color:#fff}
.arcade .faq details{background:rgba(255,255,255,.04);border-color:rgba(255,255,255,.11)}
.arcade .faq summary{color:#e6eefb}
.arcade .faq summary::after{color:var(--n-cyan)}
.arcade .gcta{background:rgba(77,163,255,.10);border:1px solid rgba(77,163,255,.3);color:#c9d8ef}
.arcade .gcta b{color:#fff}
.arcade .band{
  background:linear-gradient(120deg,#17224a,#241a52);border:1px solid rgba(181,124,255,.32);
  box-shadow:0 0 50px rgba(124,77,255,.22);
}

/* ---------- motion & small screens ---------- */
@media(max-width:620px){
  .arcade .hero{padding:40px 0 20px}
}

/* The arcade starts at the very top of the window: the global chrome above
   the page goes dark too, so there is no light strip spoiling the effect. */
.arcadepage .top{
  /* opaque, not translucent: a backdrop-filter on a sticky element forces the
     area behind it to be re-composited on every scroll frame */
  background:#0a1024;border-bottom:1px solid rgba(255,255,255,.1);backdrop-filter:none;
}
.arcadepage .brand{color:#fff}
.arcadepage .nav a{color:#b9c9e6}
.arcadepage .nav a:hover{color:#fff}
.arcadepage .nav a.btn{
  background:linear-gradient(180deg,#3f8dff,#2f6ae0);color:#fff;
  box-shadow:0 0 20px rgba(77,163,255,.4);
}
.arcadepage .burger span{background:#cfe3ff}
.arcadepage .nav.open{background:#0a1024;border-color:rgba(255,255,255,.1)}
.arcadepage .playstrip{background:linear-gradient(90deg,#120a2e,#1b1142)}

.arcade .conceptcard:has(.ic.c),.arcade .gamecard:has(.ic.c){--accent:var(--n-cyan)}
.arcade .conceptcard:has(.ic.k),.arcade .gamecard:has(.ic.k){--accent:#ff5fa2}

/* ---------- progress HUD: the arcade's score readout ---------- */
.hud{display:flex;align-items:center;gap:14px;margin-top:26px;max-width:460px}
.hud .hudlab{font-family:var(--head);font-weight:700;font-size:11.5px;letter-spacing:.18em;
  text-transform:uppercase;color:var(--n-cyan);white-space:nowrap}
.hud .hudbar{flex:1;height:9px;border-radius:99px;background:rgba(255,255,255,.08);
  border:1px solid rgba(255,255,255,.13);overflow:hidden}
.hud .hudbar i{display:block;height:100%;width:0;border-radius:99px;
  background:linear-gradient(90deg,var(--n-cyan),var(--n-blue),var(--n-purple));
  box-shadow:0 0 16px rgba(70,229,255,.65);transition:width .9s cubic-bezier(.2,.8,.2,1)}
.hud b{font-family:var(--head);font-size:14px;color:#fff;white-space:nowrap}

/* per-card cleared badge */
.arcade .clear{
  position:absolute;top:14px;right:14px;font-family:var(--head);font-weight:700;font-size:11px;
  letter-spacing:.08em;text-transform:uppercase;padding:3px 9px;border-radius:999px;
  background:rgba(255,255,255,.07);border:1px solid rgba(255,255,255,.16);color:#9fb2d0;
}
.arcade .clear.full{background:rgba(61,220,151,.14);border-color:rgba(61,220,151,.5);color:#6ff0b9;
  box-shadow:0 0 16px rgba(61,220,151,.3)}

/* ---------- illustrated card header ---------- */
.cardart{position:relative;line-height:0;overflow:hidden}
.cardart svg{display:block;width:100%;height:104px}
.cardart::after{   /* fade the art into the card so the text sits on calm ground */
  content:"";position:absolute;inset:auto 0 0;height:46px;
  background:linear-gradient(transparent,rgba(10,16,36,.55));
}
/* the art bleeds to the card edges, so the cards lose their top padding */
.arcade a.conceptcard{padding:0 18px 16px}
.arcade a.conceptcard .cardart{margin:0 -18px}
.arcade a.gamecard{padding:0 24px 22px}
.arcade a.gamecard .cardart{margin:0 -24px}
/* the emoji badge overlaps the banner, like a cover sticker */
.arcade .conceptcard .ic,.arcade .gamecard .ic{position:relative;z-index:1;margin-top:-26px;background:#0d1530!important}
.arcade a.gamecard .gic{margin-bottom:12px}
.arcade a.conceptcard .cic{margin-bottom:6px}
.arcade .cardart svg{transition:transform .25s ease-out}
.arcade a.conceptcard:hover .cardart svg,.arcade a.gamecard:hover .cardart svg{transform:scale(1.045)}
/* the cleared badge now sits over the artwork */
.arcade .clear{top:12px;right:12px;background:rgba(6,10,24,.6);backdrop-filter:none;color:#dbe7fb}
@media(prefers-reduced-motion:reduce){.arcade .cardart svg{transition:none}}

/* =======================================================================
   ARCADE — the individual game pages.
   The tokens above already turned every panel dark; what is left is the
   handful of places that hard-code a light colour, plus the page header.
   ======================================================================= */
.arcade .article-head{
  background:linear-gradient(180deg,rgba(77,163,255,.10),transparent);
  border-bottom:1px solid rgba(255,255,255,.09);position:relative;
}
.arcade .article-head::after{   /* same grid floor as the hub hero */
  content:"";position:absolute;left:0;right:0;bottom:0;height:120px;z-index:-1;pointer-events:none;
  background-image:
    linear-gradient(rgba(77,163,255,.16) 1px,transparent 1px),
    linear-gradient(90deg,rgba(77,163,255,.16) 1px,transparent 1px);
  background-size:44px 44px;
  transform:perspective(300px) rotateX(68deg);transform-origin:bottom center;
  -webkit-mask-image:linear-gradient(transparent,#000 75%);
  mask-image:linear-gradient(transparent,#000 75%);
}
.arcade .article-head .crumbs,.arcade .article-head .crumbs a{color:#8ba1c4}
.arcade .article-head .crumbs a:hover{color:var(--n-cyan)}
.arcade .article-head .lede{color:#b9c9e6}

/* buttons inside a game */
.arcade .gbtn{
  background:linear-gradient(180deg,#3f8dff,#2f6ae0);border:1px solid rgba(154,208,255,.5);color:#fff;
  box-shadow:0 6px 18px rgba(47,106,224,.35),0 0 18px rgba(77,163,255,.26);
}
.arcade .gbtn:hover{background:linear-gradient(180deg,#5a9dff,#3a78ef);box-shadow:0 8px 24px rgba(47,106,224,.5),0 0 26px rgba(77,163,255,.45)}
.arcade .gbtn.sec{background:rgba(255,255,255,.05);border:1px solid rgba(154,208,255,.35);color:#cfe3ff;box-shadow:none}
.arcade .gbtn.sec:hover{background:rgba(77,163,255,.16);border-color:var(--n-blue);box-shadow:0 0 20px rgba(77,163,255,.3)}
.arcade .levels button{background:rgba(255,255,255,.04);border-color:rgba(255,255,255,.12);color:#b4c6e3}
.arcade .levels button:hover{border-color:var(--n-blue);color:#fff;background:rgba(77,163,255,.12)}
.arcade .levels button.on{background:linear-gradient(180deg,#3f8dff,#2f6ae0);border-color:#6fb0ff;color:#fff;
  box-shadow:0 0 18px rgba(77,163,255,.5)}
.arcade .levels button.done::after{color:var(--n-green)}
.arcade .sfxtoggle{background:rgba(255,255,255,.05);border:1px solid rgba(255,255,255,.14);color:#b4c6e3}

/* panels get a faint neon edge so they read as cabinet screens */
.arcade .panel{background:linear-gradient(180deg,rgba(255,255,255,.055),rgba(255,255,255,.02));
  border-color:rgba(255,255,255,.11);box-shadow:0 10px 30px rgba(0,0,0,.3)}
.arcade .panel-h{background:rgba(255,255,255,.045);border-bottom-color:rgba(255,255,255,.1)}

/* the light-hex exceptions */
.arcade .hintbox{background:rgba(255,212,59,.10);border-left-color:var(--n-orange);color:#f0ddb4}
.arcade .hintbox b{color:#ffd36e}
.arcade .tests li{border-bottom-color:rgba(255,255,255,.08)}
.arcade .tests .mark{background:rgba(255,255,255,.07);color:#8ba1c4}
.arcade .tests li.pass .mark{background:rgba(61,220,151,.18);color:#6ff0b9}
.arcade .tests li.fail .mark{background:rgba(255,107,107,.18);color:#ff9d9d}
.arcade .tests .why{color:#ff9d9d}
.arcade .opts button{background:rgba(255,255,255,.04);border-color:rgba(255,255,255,.13);color:#e6eefb}
.arcade .opts button:hover:not([disabled]){border-color:var(--n-blue);background:rgba(77,163,255,.14)}
.arcade .opts button.right{border-color:var(--n-green);background:rgba(61,220,151,.16)}
.arcade .opts button.wrong{border-color:#ff6b6b;background:rgba(255,107,107,.16)}
.arcade .explain{background:rgba(255,255,255,.05);border-left-color:var(--n-blue)}
.arcade .bugmeta span,.arcade .chips span{background:rgba(255,255,255,.05);border-color:rgba(255,255,255,.12);color:#9fb2d0}
.arcade .overlay{background:rgba(4,7,18,.82)}
.arcade .overlay .box{background:linear-gradient(180deg,#152040,#101831);
  border:1px solid rgba(154,208,255,.28);box-shadow:0 30px 70px rgba(0,0,0,.6),0 0 50px rgba(77,163,255,.18)}
.arcade .tryit{background:rgba(77,163,255,.08);border-color:rgba(77,163,255,.45);color:#b4c6e3}
.arcade .tryit b{color:#fff}
.arcade .prose blockquote{background:rgba(255,212,59,.09);border-left-color:var(--n-orange);color:#e6dcc0}
.arcade .apilist dt{background:rgba(77,163,255,.16);color:#9fd0ff}
.arcade details.api summary{color:#e6eefb}
.arcade .boardwrap{filter:none}
.arcade .prose .card{background:rgba(255,255,255,.045);border-color:rgba(255,255,255,.11)}
.arcade .prose .card h3{color:#fff}
.arcade .related h2{color:#fff}

/* The footer and the consent banner paint themselves with var(--ink) — which
   the arcade redefines as a *light* text colour. Pin them back explicitly, or
   re-theming the tokens turns the footer white. */
.arcade footer{background:#070d1c;border-top:1px solid rgba(255,255,255,.07)}
.arcade .consent{background:#15203d;border:1px solid rgba(255,255,255,.14);color:#dbe7f5}