:root{
  --bg:#0b0f17;
  --bg2:#0e1420;
  --panel:#121a28;
  --panel2:#182234;
  --line:#25334a;
  --line2:#31435f;
  --tx:#e8eef8;
  --tx2:#9fb0c9;
  --tx3:#6c7f9c;
  --acc:#3ddc97;
  --acc2:#22b87a;
  --warn:#ffb84d;
  --r:14px;
  --r2:10px;
}

*{box-sizing:border-box}
/* class selectors like .pad-live{display:flex} outrank the UA [hidden] rule,
   so state toggling must be forced. */
[hidden]{display:none !important}
html,body{margin:0;padding:0}
html{-webkit-text-size-adjust:100%}
body{
  background:var(--bg);
  color:var(--tx);
  font:16px/1.6 -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  overflow-x:hidden;
}
a{color:var(--acc);text-decoration:none}
a:hover{text-decoration:underline}
h1,h2,h3{line-height:1.25;margin:0 0 .5em}
h2{font-size:1.5rem;margin-top:0}
h3{font-size:1.05rem;margin-top:1.6em;color:var(--tx)}
p{margin:0 0 1em}
ul{margin:0 0 1em;padding-left:1.2em}
li{margin:.4em 0}
strong{color:#fff}

.wrap{width:100%;max-width:1080px;margin:0 auto;padding:0 16px}
.narrow{max-width:760px}
.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}

/* ---------- top bar ---------- */
.topbar{
  position:sticky;top:0;z-index:20;
  background:rgba(11,15,23,.92);
  backdrop-filter:blur(8px);
  border-bottom:1px solid var(--line);
}
.topbar-in{display:flex;align-items:center;justify-content:space-between;height:52px}
.brand{font-weight:700;letter-spacing:.2px;color:var(--tx)}
.topnav{display:flex;gap:18px;font-size:.9rem}
.topnav a{color:var(--tx2)}
.topnav a:hover{color:var(--tx)}

/* ---------- tool ---------- */
.tool-section{padding:18px 0 28px}
.panel{
  background:linear-gradient(180deg,var(--panel),var(--bg2));
  border:1px solid var(--line);
  border-radius:var(--r);
  padding:16px;
}
.panel-head{margin-bottom:14px}
.panel-title{font-size:1.35rem;margin:0 0 2px}
.panel-sub{margin:0;color:var(--tx2);font-size:.9rem}

.controls{display:flex;flex-direction:column;gap:14px;margin-bottom:14px}
.control-label{font-size:.78rem;text-transform:uppercase;letter-spacing:.08em;color:var(--tx3);margin-bottom:7px}
.chips{display:flex;flex-wrap:wrap;gap:8px}
.chip{
  appearance:none;border:1px solid var(--line2);background:var(--panel2);color:var(--tx2);
  border-radius:999px;padding:7px 14px;font:inherit;font-size:.9rem;cursor:pointer;
  transition:background .12s,border-color .12s,color .12s;
  -webkit-tap-highlight-color:transparent;
}
.chip:hover{border-color:#42597a;color:var(--tx)}
.chip.is-on{background:var(--acc);border-color:var(--acc);color:#052014;font-weight:600}
.custom-chip{display:inline-flex;align-items:center;gap:4px;padding:4px 12px 4px 12px}
.custom-chip input{
  width:66px;background:transparent;border:0;outline:0;color:var(--tx);
  font:inherit;font-size:.9rem;text-align:right;padding:3px 0;
}
.custom-chip input::placeholder{color:var(--tx3)}
.custom-unit{color:var(--tx3);font-size:.85rem}
.mode-help{
  margin:8px 0 0;font-size:.86rem;color:var(--tx2);
  border-left:2px solid var(--acc2);padding-left:10px;min-height:1.4em;
}

/* ---------- pad ---------- */
.pad-wrap{margin:4px 0 0}
.pad{
  display:flex;align-items:center;justify-content:center;
  width:100%;min-height:230px;
  background:radial-gradient(120% 120% at 50% 0%,#16233a,#0f1726);
  border:1px dashed var(--line2);border-radius:var(--r);
  color:var(--tx);font:inherit;cursor:pointer;
  user-select:none;-webkit-user-select:none;-webkit-tap-highlight-color:transparent;
  touch-action:manipulation;
  transition:border-color .15s,background .15s,transform .06s;
}
.pad:hover{border-color:#4a6a94}
.pad.is-live{border-style:solid;border-color:var(--acc);background:radial-gradient(120% 120% at 50% 0%,#123227,#0f1726)}
.pad.is-hit{transform:scale(.994)}
.pad-idle{display:flex;flex-direction:column;gap:6px;align-items:center;pointer-events:none}
.pad-idle strong{font-size:1.15rem;color:#fff}
.pad-idle em{font-style:normal;font-size:.85rem;color:var(--tx3)}
.pad-live{display:flex;flex-direction:column;gap:2px;align-items:center;pointer-events:none}
.live-time{font-size:3rem;font-weight:700;font-variant-numeric:tabular-nums;color:#fff;line-height:1}
.live-row{font-size:.9rem;color:var(--tx2)}
.live-num{font-variant-numeric:tabular-nums;color:var(--acc);font-weight:600}
.live-sep{margin:0 4px;color:var(--tx3)}
.pad-note{margin:9px 0 0;font-size:.82rem;color:var(--tx3);text-align:center}

/* ---------- results ---------- */
.results{margin-top:16px;border-top:1px solid var(--line);padding-top:16px}
.score-row{display:flex;align-items:flex-end;justify-content:space-between;gap:12px;flex-wrap:wrap}
.score-main{display:flex;align-items:baseline;gap:9px}
.score-num{font-size:3.1rem;font-weight:700;color:var(--acc);font-variant-numeric:tabular-nums;line-height:1}
.score-cap{font-size:.9rem;color:var(--tx3);text-transform:uppercase;letter-spacing:.1em}
.btn-copy,.btn-ghost{
  appearance:none;font:inherit;cursor:pointer;border-radius:var(--r2);
  -webkit-tap-highlight-color:transparent;
}
.btn-copy{background:var(--acc);border:1px solid var(--acc);color:#052014;font-weight:600;padding:9px 16px;font-size:.9rem}
.btn-copy:hover{background:var(--acc2)}
.btn-ghost{background:transparent;border:1px solid var(--line2);color:var(--tx2);padding:7px 13px;font-size:.85rem}
.btn-ghost:hover{border-color:#42597a;color:var(--tx)}

.stats{display:grid;grid-template-columns:repeat(4,1fr);gap:10px;margin:16px 0 0}
.stat{background:var(--panel2);border:1px solid var(--line);border-radius:var(--r2);padding:10px 12px}
.stat-v{font-size:1.35rem;font-weight:700;font-variant-numeric:tabular-nums;color:#fff}
.stat-k{font-size:.75rem;color:var(--tx3);text-transform:uppercase;letter-spacing:.06em;margin-top:2px}

.chart-block{margin-top:16px}
.chart-head{display:flex;justify-content:space-between;align-items:baseline;gap:10px;flex-wrap:wrap;margin-bottom:6px}
.chart-title{font-size:.9rem;color:var(--tx)}
.chart-legend{font-size:.75rem;color:var(--tx3)}
#chart{display:block;width:100%;height:150px;background:var(--panel2);border:1px solid var(--line);border-radius:var(--r2)}

.best-row{display:flex;align-items:center;gap:10px;flex-wrap:wrap;margin-top:16px}
.best{font-size:.85rem;color:var(--tx2);flex:1 1 auto;min-width:180px}
.hist{margin-top:10px;border:1px solid var(--line);border-radius:var(--r2);overflow:hidden}
.hist table{width:100%;border-collapse:collapse;font-size:.85rem}
.hist th,.hist td{padding:7px 10px;text-align:left;border-bottom:1px solid var(--line)}
.hist th{color:var(--tx3);font-weight:500;font-size:.75rem;text-transform:uppercase;letter-spacing:.06em;background:var(--panel2)}
.hist td{color:var(--tx2);font-variant-numeric:tabular-nums}
.hist tr:last-child td{border-bottom:0}
.hist .empty{padding:12px;color:var(--tx3);font-size:.85rem}

/* ---------- content ---------- */
.content-section{padding:34px 0;border-top:1px solid var(--line)}
.content-section.alt{background:var(--bg2)}
.content-section p,.content-section li{color:var(--tx2)}
.formula{
  background:var(--panel2);border:1px solid var(--line);border-left:3px solid var(--acc);
  border-radius:var(--r2);padding:12px 14px;margin:0 0 1em;
  font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:.92rem;color:#fff;
  overflow-wrap:anywhere;
}
.site-foot{padding:22px 0 34px;border-top:1px solid var(--line)}
.site-foot p{margin:0;font-size:.82rem;color:var(--tx3)}
.footnav{display:flex;flex-wrap:wrap;gap:16px;margin-bottom:12px;font-size:.86rem}
.footnav a{color:var(--tx2)}
.footnav a:hover{color:var(--tx)}

/* ---------- standalone pages (about / privacy / contact) ---------- */
.page-section{padding:34px 0 46px}
.page-head{font-size:1.75rem;margin:0 0 .35em}
.page-sub{margin:0 0 1.4em;color:var(--tx2);font-size:.95rem}
.meta{margin:0 0 1.5em;color:var(--tx3);font-size:.8rem;letter-spacing:.02em}
.page-section h2{margin-top:1.7em}
.page-section p,.page-section li{color:var(--tx2)}
.page-section code{
  font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:.86em;
  background:var(--panel2);border:1px solid var(--line);border-radius:5px;
  padding:1px 5px;color:#fff;overflow-wrap:anywhere;
}
.note{
  border:1px solid var(--line);border-left:3px solid var(--warn);background:var(--panel2);
  border-radius:var(--r2);padding:12px 14px;margin:0 0 1.2em;color:var(--tx2);font-size:.92rem;
}
.note strong{color:#fff}
.mailrow{margin:0 0 1.2em}
.mail{
  display:inline-block;font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
  font-size:1rem;background:var(--panel2);border:1px solid var(--line2);
  border-radius:var(--r2);padding:9px 14px;overflow-wrap:anywhere;
}

/* ---------- mobile ---------- */
@media (max-width:720px){
  .topnav{display:none}
  .topbar-in{height:46px}
  .tool-section{padding:12px 0 22px}
  .panel{padding:13px;border-radius:12px}
  .panel-head{margin-bottom:10px}
  .panel-title{font-size:1.15rem}
  .panel-sub{font-size:.84rem;margin:0}
  .controls{gap:11px;margin-bottom:11px}
  .control-label{margin-bottom:6px}
  .chips{gap:6px}
  .chip{padding:6px 11px;font-size:.85rem}
  .custom-chip{padding:3px 10px}
  .custom-chip input{width:52px;font-size:.85rem}
  .mode-help{margin-top:6px;font-size:.82rem}
  .pad{min-height:158px}
  .live-time{font-size:2.4rem}
  .pad-note{margin-top:7px;font-size:.78rem}
  .score-num{font-size:2.5rem}
  .stats{grid-template-columns:repeat(2,1fr);gap:8px}
  .score-row{align-items:center}
  .btn-copy{width:100%;text-align:center;padding:11px 16px}
  h2{font-size:1.28rem}
  .content-section{padding:26px 0}
  .page-section{padding:22px 0 32px}
  .page-head{font-size:1.4rem}
  .page-sub{font-size:.9rem}
  .footnav{gap:10px 16px;font-size:.8rem}
  .page-section h2{font-size:1.15rem}
  .note{padding:11px 12px;font-size:.88rem}
}
@media (max-width:380px){
  .stats{grid-template-columns:1fr 1fr}
  .chip{padding:6px 10px;font-size:.82rem}
}
@media (prefers-reduced-motion:reduce){
  *{transition:none !important}
}