:root{
  --bg:#0f141b;
  --panel:#121a23;
  --card:#151f2a;
  --text:#e9eef5;
  --muted:#9fb0c3;
  --line:#263445;
  --accent:#79c0ff;

  --calcBody:#2f4556;
  --calcBody2:#2b3f50;
  --lcdBg:#d6dfc6;
  --lcdInk:#101a12;
  --key:#3c566b;
  --key2:#3a5164;
  --keyText:#eaf2fb;
  --keyFn:#2e475b;
  --keyOp:#3e5e76;
  --keyEq:#4a6d86;
  --warn:#b07a3e;
  --danger:#9d3d3d;
}

*{box-sizing:border-box}
html,body{height:100%}
body{
  margin:0;
  background:radial-gradient(1200px 800px at 30% 10%, #182434 0%, var(--bg) 55%, #0b0f14 100%);
  color:var(--text);
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Arial;
}

.shell{max-width:1200px;margin:0 auto;padding:18px}

.topbar{display:flex;gap:16px;align-items:flex-end;justify-content:space-between;flex-wrap:wrap;margin-bottom:14px}
.brand{display:flex;gap:12px;align-items:center}
.brandMark{
  width:34px;height:34px;border-radius:10px;
  background: linear-gradient(145deg, #2f77b8, #5db5ff);
  box-shadow: 0 10px 30px rgba(121,192,255,.18);
}
.brandTitle{font-weight:800;letter-spacing:.2px}
.brandSub{color:var(--muted);font-size:13px;margin-top:2px}

.tabs{display:flex;gap:8px;flex-wrap:wrap}
.tab{
  border:1px solid var(--line);
  background:rgba(21,31,42,.6);
  color:var(--text);
  padding:10px 12px;
  border-radius:12px;
  cursor:pointer;
  font-weight:800;
}
.tab.active{
  background:rgba(121,192,255,.12);
  border-color:rgba(121,192,255,.35);
}

.panel{display:none}
.panel.active{display:block}

.card{
  border:1px solid var(--line);
  background:rgba(21,31,42,.7);
  border-radius:18px;
  padding:16px;
  box-shadow: 0 16px 60px rgba(0,0,0,.25);
}

.cardHeader h1{margin:0 0 4px 0;font-size:20px}
.cardHeader p{margin:0;color:var(--muted)}

.row{display:flex;gap:10px;align-items:end;margin-top:14px;flex-wrap:wrap}
.row.two{align-items:stretch}
.row.two > .field{flex:1;min-width:240px}

.field{display:flex;flex-direction:column;gap:6px;flex:1;min-width:240px}
.label{color:var(--muted);font-size:12px;font-weight:800;letter-spacing:.3px;text-transform:uppercase}

.input{
  width:100%;
  padding:12px 12px;
  border-radius:14px;
  border:1px solid var(--line);
  background:rgba(10,14,20,.55);
  color:var(--text);
  outline:none;
}
.input:focus{border-color:rgba(121,192,255,.6); box-shadow:0 0 0 4px rgba(121,192,255,.08)}
.mono{font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono","Courier New", monospace}

.hint{color:var(--muted);font-size:12px;min-height:16px}
.outputWrap{display:flex;gap:10px;align-items:center}
.outputWrap .input{flex:1}

.btn{
  padding:12px 12px;
  border-radius:14px;
  border:1px solid rgba(121,192,255,.35);
  background:rgba(121,192,255,.12);
  color:var(--text);
  font-weight:900;
  cursor:pointer;
  white-space:nowrap;
}
.btn:hover{background:rgba(121,192,255,.18)}
.btn.secondary{
  border-color:var(--line);
  background:rgba(10,14,20,.45);
}
.btn.secondary:hover{background:rgba(10,14,20,.65)}

.note{
  margin-top:14px;
  color:var(--muted);
  font-size:13px;
  border-top:1px dashed rgba(38,52,69,.7);
  padding-top:12px;
}

.grid{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin-top:12px}
.mini{border:1px solid var(--line);border-radius:18px;padding:14px;background:rgba(21,31,42,.55)}
.mini h2{margin:0 0 10px 0;font-size:16px}
.chips{display:flex;gap:8px;flex-wrap:wrap}
.chip{
  border:1px solid var(--line);
  background:rgba(10,14,20,.45);
  color:var(--text);
  padding:8px 10px;
  border-radius:999px;
  cursor:pointer;
  font-weight:800;
  font-size:13px;
}
.chip:hover{background:rgba(10,14,20,.65)}
.formatRow{display:flex;gap:12px;align-items:center;flex-wrap:wrap}
.toggle{display:flex;gap:8px;align-items:center;color:var(--muted);font-weight:800}

.footer{margin-top:18px;color:var(--muted);font-size:12px;text-align:center}

/* --- Calculator --- */
.calcWrap{display:grid;grid-template-columns: 1.1fr .9fr;gap:12px;align-items:start}
@media (max-width:980px){ .calcWrap{grid-template-columns:1fr} }

.calcBody{
  border-radius:22px;
  padding:14px;
  background: linear-gradient(160deg, var(--calcBody), var(--calcBody2));
  border:1px solid rgba(255,255,255,.08);
  box-shadow: 0 20px 70px rgba(0,0,0,.28);
}
.calcTop{
  display:flex;justify-content:space-between;align-items:center;
  margin-bottom:10px;
}
.calcBadge{font-weight:900;color:rgba(255,255,255,.8);font-size:12px;letter-spacing:.3px}
.calcModel{font-weight:900;font-size:12px;color:rgba(255,255,255,.65);letter-spacing:.6px}

.lcdArea{display:flex;gap:12px;align-items:stretch;margin-bottom:12px;flex-wrap:wrap}
.lcd{
  flex:1;min-width:260px;border-radius:18px;
  background: linear-gradient(180deg, var(--lcdBg), #cfd8bf);
  border:1px solid rgba(0,0,0,.2);
  box-shadow: inset 0 6px 18px rgba(0,0,0,.12);
  padding:12px 12px 10px 12px;color:var(--lcdInk);
}
.seg .lcdLineBig,.seg .lcdLineSmall{
  text-shadow:0 1px 0 rgba(255,255,255,.35),0 -1px 0 rgba(0,0,0,.2),0 0 6px rgba(16,26,18,.35);
  letter-spacing:.5px;
}
.lcdFlags{display:flex;gap:8px;align-items:center;margin-bottom:6px}
.flag{font-size:11px;font-weight:900;opacity:.35;padding:2px 6px;border-radius:8px;background:rgba(16,26,18,.08)}
.flag.on{opacity:.95}
.lcdLineSmall{min-height:16px;font-size:12px;opacity:.8}
.lcdLineBig{font-size:32px;font-weight:900;line-height:1.1;min-height:40px;overflow:hidden;white-space:nowrap;text-overflow:ellipsis}

.lcdSide{min-width:160px;display:flex;flex-direction:column;gap:8px;justify-content:center}
.tiny{font-size:12px;color:rgba(255,255,255,.75)}

.keypad{display:grid;grid-template-columns: repeat(4, 1fr);gap:9px}
.key{
  border:1px solid rgba(0,0,0,.25);
  background: linear-gradient(180deg, var(--key), var(--key2));
  color:var(--keyText);
  border-radius:16px;
  padding:12px 10px;
  font-weight:900;
  cursor:pointer;
  user-select:none;
  box-shadow: 0 10px 18px rgba(0,0,0,.18);
}
.key:hover{filter:brightness(1.05)}
.key:active{transform:translateY(1px)}
.key.fn{background: linear-gradient(180deg, var(--keyFn), #2b4255)}
.key.op{background: linear-gradient(180deg, var(--keyOp), #37556c)}
.key.eq{background: linear-gradient(180deg, var(--keyEq), #3f5f76);border-color: rgba(121,192,255,.25)}
.key.warn{background: linear-gradient(180deg, #9b6a35, var(--warn))}
.key.danger{background: linear-gradient(180deg, #8f2f2f, var(--danger))}
.key.num{background: linear-gradient(180deg, #5c6f7f, #4f6374)}
.key.num.wide{grid-column: span 1}

.calcFooter{margin-top:10px}
#calcError{color:#ffb4b4;min-height:18px}

/* --- Quick Calculators --- */
.qcGrid{
  margin-top:14px;
  display:grid;
  grid-template-columns: repeat(2, minmax(0,1fr));
  gap:12px;
}
@media (max-width:980px){ .qcGrid{grid-template-columns:1fr} }

.qcCard{
  border:1px solid var(--line);
  background:rgba(10,14,20,.35);
  border-radius:18px;
  padding:14px;
}
.qcCard h2{margin:0 0 8px 0;font-size:16px}
.qcCard h3.subh{margin:14px 0 0 0;font-size:14px;color:rgba(233,238,245,.9)}
.qcOut{margin-top:10px;border-top:1px dashed rgba(38,52,69,.6);padding-top:10px}
.qcLine{display:flex;justify-content:space-between;gap:10px;padding:6px 0;color:rgba(233,238,245,.92)}
.hr{border:0;border-top:1px dashed rgba(38,52,69,.6);margin:12px 0}

.qcTabs{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:8px}
.qcTab{
  border:1px solid var(--line);
  background:rgba(21,31,42,.35);
  color:var(--text);
  padding:8px 10px;
  border-radius:999px;
  cursor:pointer;
  font-weight:900;
  font-size:12px;
}
.qcTab.active{border-color:rgba(121,192,255,.35);background:rgba(121,192,255,.12)}
.qcPanel{display:none}
.qcPanel.active{display:block}


/* Utilities */

.row{display:flex;flex-wrap:wrap;gap:10px;align-items:center;margin-top:10px;}
.btn{padding:10px 14px;border-radius:14px;border:1px solid rgba(255,255,255,.14);background:rgba(255,255,255,.06);color:inherit}
.btn.ghost{background:transparent}
.btn:disabled{opacity:.6;cursor:not-allowed}
.check{display:flex;gap:10px;align-items:center;padding:10px 12px;border:1px solid rgba(255,255,255,.14);border-radius:14px;background:rgba(255,255,255,.03)}
.kv{display:grid;gap:8px;margin-top:12px}
.kv>div{display:flex;justify-content:space-between;gap:14px}
#dpOverlay{position:fixed;inset:0;z-index:99999;display:none;align-items:center;justify-content:center;background:#000}
#dpHud{position:absolute;top:14px;left:14px;padding:10px 12px;border-radius:14px;background:rgba(0,0,0,.45);border:1px solid rgba(255,255,255,.16);color:#fff;backdrop-filter:blur(10px);font-family:ui-monospace,Menlo,Consolas,monospace}
#dpHud small{display:block;opacity:.8;margin-top:4px}