:root {
  --tangelo:#EE7526; --mustard:#FBD652; --vermilion:#D74820;
  --plum:#77161C;    --rich-black:#030519;
  --cream:#F5EEE5;   --beige:#EFEDE9;
  --off-white:#F5F5F5; --pastel-grey:#5C5C5C;
  --bg:#FFFFFF; --panel:var(--off-white); --panel-2:#FFFFFF;
  --border:var(--plum);
  --fg:var(--pastel-grey); --fg-strong:var(--rich-black); --fg-faint:#BFBFBF;
  --accent:var(--tangelo); --accent-hover:var(--vermilion);
  --radius:12px; --radius-sm:8px;
  --shadow:0 6px 20px rgba(3,5,25,.06), 0 1px 2px rgba(3,5,25,.04);
}
*{box-sizing:border-box}
html,body{margin:0;padding:0;min-height:100%}
body{
  background:
    radial-gradient(1100px 500px at 20% -150px, rgba(238,117,38,.06) 0%, transparent 60%),
    radial-gradient(900px 500px at 110% 0%, rgba(251,214,82,.08) 0%, transparent 60%),
    var(--bg);
  color:var(--fg);
  font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, Inter, sans-serif;
  -webkit-font-smoothing:antialiased; min-height:100dvh;
}

.wrap{
  max-width:560px;
  margin:0 auto;
  padding:96px 20px 40px; /* top room for the shared sticky banner */
}

.hdr{ text-align:center; margin-bottom:18px }
.title{
  margin:0;
  font-size:30px;
  font-weight:800;
  letter-spacing:-0.03em;
  color:var(--fg-strong);
  line-height:1.1;
}
.title .accent{ color:var(--accent) }
.sub{
  margin:6px 0 0;
  font-size:11px;
  font-weight:600;
  letter-spacing:.18em;
  text-transform:uppercase;
  color:var(--pastel-grey);
}

.info{
  background:var(--panel);
  border:1px solid var(--border);
  border-radius:var(--radius);
  padding:12px 14px;
  margin:0 0 16px;
  box-shadow:var(--shadow);
  display:flex;
  flex-direction:column;
  gap:6px;
}
.info-row{
  display:flex;
  justify-content:space-between;
  align-items:baseline;
  gap:12px;
}
.info-label{
  font-size:10px;
  font-weight:700;
  letter-spacing:.16em;
  text-transform:uppercase;
  color:var(--pastel-grey);
}
.info-pair, .info-val{
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size:14px;
  font-weight:700;
  color:var(--fg-strong);
  letter-spacing:.05em;
}
.info-pair #info-start{ background:var(--mustard); padding:1px 6px; border-radius:4px; color:var(--rich-black) }
.info-pair #info-end{ background:var(--tangelo); padding:1px 6px; border-radius:4px; color:#fff }

.board{
  display:flex;
  flex-direction:column;
  gap:8px;
  align-items:center;
  margin:8px 0 16px;
}
.row{
  display:grid;
  grid-template-columns:repeat(5, 1fr);
  gap:8px;
  width:100%;
  max-width:420px;
}
.cell{
  aspect-ratio:1/1;
  display:flex;
  align-items:center;
  justify-content:center;
  background:var(--panel-2);
  border:1px solid var(--border);
  border-radius:var(--radius-sm);
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-weight:800;
  font-size:clamp(20px, 6vw, 28px);
  color:var(--fg-strong);
  letter-spacing:.04em;
  text-transform:uppercase;
  user-select:none;
  cursor:pointer;
  transition: transform .06s ease, background-color .12s ease, border-color .12s ease;
}
.cell:focus{ outline:none; border-color:var(--accent); box-shadow:0 0 0 2px rgba(238,117,38,.25) }
.cell.active{ border-color:var(--accent) }
.cell.active.caret{ box-shadow:inset 0 -3px 0 0 var(--accent) }
.cell.changed{ background:var(--tangelo); color:#fff; border-color:var(--accent) }
.cell.locked{ cursor:default }
.row.start .cell{ background:var(--mustard); color:var(--rich-black); border-color:var(--plum) }
.row.end   .cell{ background:var(--tangelo); color:#fff; border-color:var(--plum) }
.row.done  .cell{ background:var(--cream); color:var(--fg-strong); border-color:var(--plum) }
.row.hinted .cell{ background:var(--beige); color:var(--fg-strong); border-color:var(--accent); border-style:dashed }
.row.given  .cell{ background:var(--off-white); color:var(--pastel-grey); border-color:var(--fg-faint); border-style:dashed }

.controls{
  display:flex;
  gap:10px;
  justify-content:center;
  flex-wrap:wrap;
  margin-bottom:14px;
}
.btn{
  appearance:none;
  -webkit-appearance:none;
  background:var(--accent);
  color:#fff;
  border:1px solid var(--accent);
  border-radius:var(--radius-sm);
  padding:9px 16px;
  font-size:12px;
  font-weight:700;
  letter-spacing:.14em;
  text-transform:uppercase;
  cursor:pointer;
  transition: background-color .12s ease, border-color .12s ease, transform .06s ease;
}
.btn:hover{ background:var(--accent-hover); border-color:var(--accent-hover) }
.btn:active{ transform: translateY(1px) }
.btn-ghost{
  background:transparent;
  color:var(--plum);
  border-color:var(--plum);
}
.btn-ghost:hover{ background:var(--plum); color:#fff; border-color:var(--plum) }

.status{
  min-height:24px;
  text-align:center;
  font-size:13px;
  color:var(--pastel-grey);
}
.status.err{ color:var(--vermilion); font-weight:600 }
.status.ok{ color:var(--plum); font-weight:600 }

.loading{ text-align:center; padding:8px 0 }
.muted{ color:var(--pastel-grey); font-size:13px; margin:0 }

.errbox{
  text-align:center;
  background:var(--panel);
  border:1px solid var(--vermilion);
  border-radius:var(--radius);
  padding:14px;
  margin:0 0 16px;
}
.err{ color:var(--vermilion); margin:0 0 10px; font-weight:600 }

.overlay{
  position:fixed; inset:0;
  background:rgba(3,5,25,.45);
  display:flex; align-items:center; justify-content:center;
  padding:20px;
  z-index:50;
}
/* Higher specificity than `.overlay` so the HTML `hidden` attribute wins
 * over the class's `display:flex`. Without this, the overlay shows from
 * page load and the Close button appears not to work. */
.overlay[hidden]{ display:none !important; }
.overlay-card{
  background:#fff;
  border:1px solid var(--plum);
  border-radius:var(--radius);
  padding:22px 24px;
  max-width:380px;
  width:100%;
  text-align:center;
  box-shadow:var(--shadow);
}
.ov-title{
  margin:0 0 8px;
  font-size:24px;
  font-weight:800;
  letter-spacing:-0.02em;
  color:var(--fg-strong);
}
.ov-body{
  margin:0 0 16px;
  color:var(--pastel-grey);
  font-size:14px;
  line-height:1.5;
}
.ov-body strong{ color:var(--fg-strong); font-weight:700 }
.ov-actions{ display:flex; justify-content:center; gap:10px }

@media (max-width:420px){
  .wrap{ padding-top:88px }
  .row{ gap:6px }
  .cell{ border-radius:6px }
  .controls .btn{ padding:8px 12px; font-size:11px }
}