:root{
  --bg:#0b1218;
  --panel:rgba(255,255,255,.045);
  --panel-2:rgba(255,255,255,.075);
  --line:rgba(150,196,214,.16);
  --line-2:rgba(150,196,214,.32);
  --text:#e7f2f6;
  --text-2:#a6bec9;
  --text-3:#6d8792;
  --text-4:#456170;
  --accent:#4fd0e0;
  --accent-dim:#2b7b8a;
  --chk:#f2b95c;
  --chk-dim:#8a6a2c;
  --bad:#ff6d54;
  --good:#5fdb9f;
  --slate:#0d1a22;
  --sans:'Inter',-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,sans-serif;
  --serif:'Instrument Serif',Georgia,'Times New Roman',serif;
  --mono:'IBM Plex Mono',ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
}
*{margin:0;padding:0;box-sizing:border-box}
[hidden]{display:none !important}
body.boot *{transition:none !important; animation:none !important}
html,body{height:100%}
body{
  background:var(--bg); color:var(--text); font-family:var(--sans);
  -webkit-font-smoothing:antialiased;
  background-image:radial-gradient(130% 95% at 50% -8%, #172b36 0%, #0d1a22 52%, #070d12 100%);
  background-attachment:fixed;
}
:focus-visible{outline:2px solid var(--accent); outline-offset:2px; border-radius:6px}
button{font-family:inherit; color:inherit; background:none; border:none}

.page{display:flex; flex-direction:column; min-height:100vh}

/* ---------- top bar ---------- */
.bar{
  display:flex; justify-content:space-between; align-items:center; gap:12px;
  padding:max(14px, env(safe-area-inset-top)) 20px 0; flex:none;
}
.home,.icon{
  display:inline-flex; align-items:center; gap:7px; height:38px;
  color:var(--text); text-decoration:none; font:500 14px/1 var(--sans);
  background:var(--panel); border:1px solid var(--line); border-radius:999px;
  cursor:pointer; transition:background .15s, border-color .15s;
}
.home{padding:0 14px 0 10px}
.home span{font-family:var(--serif); font-size:18px; letter-spacing:.01em}
.icon{width:38px; justify-content:center; padding:0}
.home:hover,.icon:hover{background:var(--panel-2); border-color:var(--line-2)}

/* ---------- layout ---------- */
main{
  flex:1; display:grid; grid-template-columns:minmax(0,1fr) 344px;
  gap:26px; padding:10px 20px max(22px, env(safe-area-inset-bottom));
  align-items:start; align-content:start;
  width:100%; max-width:1104px; margin:0 auto;
}
.stage{display:flex; flex-direction:column; gap:15px; min-width:0}
.titleblock{max-width:640px; padding:6px 2px 0}
.kicker{font-size:11.5px; font-weight:600; letter-spacing:.15em; text-transform:uppercase; color:var(--text-3)}
h1{
  font-family:var(--serif); font-weight:400; font-size:clamp(34px, 4.4vw, 58px);
  line-height:.98; letter-spacing:-.01em; margin:4px 0 8px;
}
.sub{font-size:14.5px; line-height:1.55; color:var(--text-2); max-width:64ch}
.sub em{color:var(--text); font-style:italic; font-family:var(--serif); font-size:17.5px}
.sub b{font-weight:600; color:var(--text)}
.lbl{
  font-size:11px; font-weight:600; letter-spacing:.12em; text-transform:uppercase;
  color:var(--text-3); display:flex; justify-content:space-between; align-items:baseline; gap:8px;
}
.lbl .hint{font-size:10px; font-weight:500; letter-spacing:.05em; text-transform:none; color:var(--text-4)}
.srlive{position:absolute; width:1px; height:1px; overflow:hidden; clip:rect(0 0 0 0); white-space:nowrap}
.code{font:600 12px/1 var(--mono); letter-spacing:.06em; color:var(--accent); text-transform:none}

/* ---------- the block ---------- */
.slate{
  background:var(--slate); border-radius:18px; border:1px solid rgba(120,180,200,.11);
  padding:16px 16px 12px; min-width:0;
  box-shadow:0 1px 0 rgba(180,225,240,.07) inset, 0 20px 40px -26px #000;
  background-image:radial-gradient(115% 130% at 18% 0%, #16252e 0%, #0d1a22 66%);
}
.board{display:flex; justify-content:center}
.grid{
  display:grid; grid-template-columns:repeat(4, 1fr); gap:10px;
  width:100%; max-width:520px;
}
.cell{
  position:relative; aspect-ratio:1; border-radius:13px; cursor:pointer;
  display:grid; place-items:center;
  background:#0c161d; border:1px solid rgba(120,180,200,.14);
  transition:background .16s, border-color .16s, box-shadow .16s, opacity .16s, filter .16s, transform .07s;
}
.cell:active{transform:scale(.97)}
.cell .idx{
  position:absolute; top:7px; left:8px; display:flex; gap:1.5px;
  font:600 9.5px/1 var(--mono); letter-spacing:.06em; color:var(--text-4);
}
.cell .idx .b{transition:color .16s, text-shadow .16s}
.cell .tag{
  position:absolute; bottom:6px; right:8px;
  font:600 8.5px/1 var(--sans); letter-spacing:.1em; text-transform:uppercase;
  color:var(--text-4);
}
.cell .val{
  font:600 clamp(21px, 4.6vw, 32px)/1 var(--mono);
  color:#33505e; transition:color .16s, text-shadow .16s;
}
.cell .mark{
  position:absolute; top:7px; right:8px; width:7px; height:7px; border-radius:50%;
  background:transparent; transition:background .16s, box-shadow .16s;
}

/* data bits */
.cell.databit.on{background:#0e2530; border-color:rgba(79,208,224,.3)}
.cell.databit.on .val{color:var(--accent); text-shadow:0 0 16px rgba(79,208,224,.4)}
/* check bits */
.cell.chkbit{border-style:dashed; border-color:rgba(242,185,92,.22); background:#110f0c}
.cell.chkbit .tag{color:var(--chk-dim)}
.cell.chkbit.on{background:#1e1808; border-color:rgba(242,185,92,.42)}
.cell.chkbit.on .val{color:var(--chk); text-shadow:0 0 16px rgba(242,185,92,.35)}
/* hover */
.cell.databit:hover,.cell.chkbit:hover{border-color:rgba(160,215,232,.55)}
/* highlighted check region: the eight it asks about stay lit, the rest step back */
.grid.hlon .cell{opacity:.26; filter:saturate(.35)}
.grid.hlon .cell.in{opacity:1; filter:none; box-shadow:0 0 0 1px rgba(242,185,92,.5)}
.grid.hl8 .b8,.grid.hl4 .b4,.grid.hl2 .b2,.grid.hl1 .b1{color:var(--chk); text-shadow:0 0 10px rgba(242,185,92,.5)}
/* damaged */
.cell.databit.bad,.cell.chkbit.bad,
.cell.databit.bad:hover,.cell.chkbit.bad:hover{
  border-style:solid; border-color:var(--bad); background:#2a110d; background-image:none;
}
.cell.databit.bad .val,.cell.chkbit.bad .val{color:#ff8d78; text-shadow:0 0 16px rgba(255,109,84,.45)}
.cell.bad .mark{background:var(--bad); box-shadow:0 0 0 3px rgba(255,109,84,.2)}
.cell.healed .mark{background:var(--good); box-shadow:0 0 0 3px rgba(95,219,159,.18)}
/* the bit the address points at */
.cell.point::after{
  content:''; position:absolute; inset:-5px; border-radius:17px;
  border:2px solid var(--chk); pointer-events:none;
  animation:ping 1.6s ease-out infinite;
}
@keyframes ping{
  0%{transform:scale(1); opacity:.95}
  70%{transform:scale(1.07); opacity:.18}
  100%{transform:scale(1); opacity:.95}
}
.cell.nudge{animation:nudge .32s ease}
@keyframes nudge{
  0%,100%{transform:translateX(0)}
  25%{transform:translateX(-4px)}
  75%{transform:translateX(4px)}
}

/* ---------- message readout ---------- */
.pay{
  display:flex; align-items:baseline; gap:9px; flex-wrap:wrap;
  padding:14px 4px 0; margin-top:14px; border-top:1px solid rgba(120,180,200,.1);
}
.plab{
  font:600 10px/1 var(--sans); letter-spacing:.14em; text-transform:uppercase;
  color:var(--text-4); flex:none;
}
.pbits{font:600 13px/1.4 var(--mono); letter-spacing:.14em; color:var(--text-2)}
.pbits b{color:var(--bad); font-weight:600}
.pnum{font:400 15px/1 var(--serif); color:var(--text-3)}
.pflag{font:500 11.5px/1 var(--sans); letter-spacing:.02em; color:var(--text-4); margin-left:auto}
.pflag.ok{color:var(--good)}
.pflag.no{color:var(--bad)}

.under{
  display:flex; align-items:center; justify-content:space-between; gap:16px;
  padding:9px 4px 2px; min-height:36px;
}
.say{font-size:12.5px; line-height:1.45; color:var(--text-2); min-width:0}
.say b{color:var(--text); font-weight:600}
.say .n{font:600 12px/1 var(--mono); color:var(--chk)}
.legend{display:flex; gap:13px; flex:none; flex-wrap:wrap; justify-content:flex-end}
.legend span{
  display:inline-flex; align-items:center; gap:5px; white-space:nowrap;
  font:500 10.5px/1 var(--sans); letter-spacing:.04em; color:var(--text-4);
}
.sw{width:11px; height:11px; border-radius:3px; display:inline-block; flex:none}
.sw.s-data{background:#0e2530; border:1px solid rgba(79,208,224,.55)}
.sw.s-chk{background:#1e1808; border:1px dashed rgba(242,185,92,.7)}
.sw.s-bad{background:#28100c; border:1px solid var(--bad)}

/* ---------- panel ---------- */
.panel{
  display:flex; flex-direction:column; gap:13px; position:sticky; top:12px;
  background:var(--panel); border:1px solid var(--line); border-radius:16px;
  padding:15px 15px 13px;
}
.grp{display:flex; flex-direction:column; gap:8px}
.note{font-size:11.5px; line-height:1.5; color:var(--text-3)}
.note b{color:var(--text-2); font-weight:600}

.seg{display:flex; gap:5px}
.seg button{
  flex:1; height:34px; border-radius:9px; cursor:pointer; padding:0 2px;
  background:var(--panel-2); border:1px solid var(--line);
  font:600 12.5px/1 var(--sans); color:var(--text-2);
  transition:background .14s, border-color .14s, color .14s;
}
.seg button:hover{border-color:var(--line-2); color:var(--text)}
.seg button.is-on{background:var(--accent); border-color:var(--accent); color:#06222a}

/* --- the four checks --- */
.checks{display:flex; flex-direction:column; gap:5px}
.chk{
  display:flex; align-items:center; gap:10px; width:100%; cursor:pointer;
  padding:6px 10px 6px 8px; border-radius:10px; text-align:left;
  background:var(--panel-2); border:1px solid var(--line);
  transition:background .14s, border-color .14s;
}
.chk .mini{flex:none; width:30px; height:30px; display:block}
.chk .ct{display:flex; flex-direction:column; gap:2px; min-width:0; flex:1}
.chk .cname{font:600 12.5px/1.1 var(--sans); color:var(--text)}
.chk .cres{font:500 10.5px/1.1 var(--sans); color:var(--text-3)}
.chk .cbit{
  flex:none; font:600 18px/1 var(--mono); color:var(--text-4);
  width:16px; text-align:center;
}
.chk.fail{border-color:rgba(255,109,84,.4); background:rgba(255,109,84,.08)}
.chk.fail .cres{color:#ff9f8b}
.chk.fail .cbit{color:var(--bad)}
.chk.pass .cbit{color:var(--good); opacity:.55}
.chk:hover,.chk.pin,.chk.fail:hover,.chk.fail.pin{
  border-color:rgba(242,185,92,.85); background:rgba(242,185,92,.15);
}
.chk.wide{gap:9px}
.chk.wide .cname{font-size:12px}
.chkdiv{
  font:500 10.5px/1.45 var(--sans); color:var(--text-4);
  padding:5px 2px 2px; margin:0;
}

/* --- address --- */
.addr{display:flex; gap:6px}
.abit{
  flex:1; border-radius:10px; padding:9px 0 6px; text-align:center;
  background:#0c161d; border:1px solid var(--line);
  transition:background .16s, border-color .16s;
}
.abit .d{font:600 24px/1 var(--mono); color:var(--text-4); transition:color .16s}
.abit .w{
  display:block; margin-top:4px;
  font:600 9px/1 var(--sans); letter-spacing:.12em; color:var(--text-4);
}
.abit.one{background:#28100c; border-color:rgba(255,109,84,.45)}
.abit.one .d{color:var(--bad); text-shadow:0 0 14px rgba(255,109,84,.4)}
.addrfoot{font:400 16px/1.3 var(--serif); color:var(--text-2); min-height:1.3em}
.addrfoot .big{font-size:27px; color:var(--chk); line-height:1}
.addrfoot .m{font:600 12px/1 var(--mono); letter-spacing:.08em; color:var(--text-3)}

/* --- verdict --- */
.verd{
  border-radius:12px; padding:11px 12px; border:1px solid var(--line);
  background:var(--panel-2); font-size:12.5px; line-height:1.5; color:var(--text-2);
}
.verd b{color:var(--text); font-weight:600}
.verd .h{
  display:block; font:600 12.5px/1.3 var(--sans); color:var(--text); margin-bottom:3px;
}
.verd.clean{border-color:rgba(95,219,159,.34); background:rgba(95,219,159,.08)}
.verd.clean .h{color:var(--good)}
.verd.one{border-color:rgba(242,185,92,.4); background:rgba(242,185,92,.08)}
.verd.one .h{color:var(--chk)}
.verd.two{border-color:rgba(255,109,84,.42); background:rgba(255,109,84,.09)}
.verd.two .h{color:#ff9f8b}
.verd .warn{display:block; margin-top:6px; color:#ff9f8b; font-size:11.5px}

.row{display:flex; gap:6px}
.btn{
  display:flex; flex-direction:column; gap:2px; text-align:left;
  padding:8px 11px; border-radius:10px; cursor:pointer;
  background:var(--panel-2); border:1px solid var(--line);
  transition:background .14s, border-color .14s, transform .08s, color .14s;
}
.btn:hover{background:rgba(255,255,255,.12); border-color:var(--line-2)}
.btn:active{transform:translateY(1px)}
.btn.wide{
  align-items:center; justify-content:center; text-align:center; flex:1;
  font:600 12.5px/1 var(--sans); padding:0 6px; height:36px; color:var(--text-2);
}
.btn.wide:hover{color:var(--text)}
.btn:disabled{opacity:.38; cursor:default}
.btn:disabled:hover{background:var(--panel-2); border-color:var(--line); color:var(--text-2)}
.btn.fix{
  align-items:center; justify-content:center; text-align:center; height:40px;
  font:600 13.5px/1 var(--sans); color:#06222a;
  background:var(--chk); border-color:var(--chk);
}
.btn.fix:hover{background:#ffcf7c; border-color:#ffcf7c}
.btn.fix:disabled{background:var(--panel-2); border-color:var(--line); color:var(--text-3)}
.btn.fix:disabled:hover{background:var(--panel-2)}

.foot{
  font-size:11.5px; line-height:1.6; color:var(--text-4);
  border-top:1px solid var(--line); padding-top:12px;
}
.link{
  color:var(--accent); cursor:pointer; font:inherit; font-weight:600; text-align:left;
  text-decoration:underline; text-underline-offset:2px;
}
.link:hover{color:#8ee6f2}

/* ---------- about ---------- */
dialog{
  border:none; padding:0; background:transparent; max-width:min(700px, 92vw);
  max-height:86vh; margin:auto;
}
dialog::backdrop{background:rgba(4,10,14,.66); backdrop-filter:blur(3px)}
.about{
  position:relative; background:#0f1c24; border:1px solid rgba(150,196,214,.2);
  border-radius:18px; padding:26px 28px 24px; overflow-y:auto; max-height:86vh;
  box-shadow:0 30px 60px -28px #000;
}
.about h2{
  font-family:var(--serif); font-weight:400; font-size:31px; line-height:1.05;
  margin:4px 0 14px; color:var(--text);
}
.about p{font-size:14.5px; line-height:1.68; color:var(--text-2); margin-bottom:12px}
.about p b{color:var(--text); font-weight:600}
.about em,.about i{font-style:italic}
.about sup{font-size:.7em}
.about .fine{
  font-size:12.5px; color:var(--text-3); border-top:1px solid var(--line);
  padding-top:12px; margin-top:16px; margin-bottom:0;
}
.about .code{font-size:12px; color:var(--accent)}
kbd{
  font:600 11px/1.6 var(--mono); background:rgba(255,255,255,.07);
  border:1px solid var(--line-2); border-bottom-width:2px; border-radius:5px; padding:1px 5px;
}
.x{
  position:absolute; top:14px; right:14px; width:32px; height:32px; cursor:pointer;
  display:flex; align-items:center; justify-content:center; color:var(--text-3);
  background:var(--panel-2); border:1px solid var(--line); border-radius:999px;
}
.x:hover{color:var(--text); border-color:var(--line-2)}

/* ---------- narrow ---------- */
@media (max-width:920px){
  main{grid-template-columns:minmax(0,1fr); gap:16px; padding:8px 14px max(20px, env(safe-area-inset-bottom))}
  .panel{position:static}
  .titleblock{padding-top:2px}
  h1{font-size:clamp(30px, 8.6vw, 42px)}
  .sub{font-size:14px}
  .slate{padding:12px 12px 10px; border-radius:15px}
  .grid{gap:8px}
  .cell{border-radius:11px}
  .cell .val{font-size:clamp(20px, 6.6vw, 30px)}
  .under{flex-direction:column; align-items:flex-start; gap:8px}
  .legend{justify-content:flex-start}
  .pflag{margin-left:0}
  .about{padding:22px 20px 20px; border-radius:15px}
  .about h2{font-size:26px}
}
@media (max-width:420px){
  .cell .idx{top:5px; left:6px; font-size:8.5px; letter-spacing:.02em}
  .cell .tag{bottom:4px; right:6px; font-size:8px}
  .cell .mark{top:5px; right:6px; width:6px; height:6px}
}

@media (prefers-reduced-motion:reduce){
  *{transition-duration:.01ms !important}
  .cell.point::after{animation:none}
  .cell.nudge{animation:none}
}