:root{
  --bg:#171a1f;
  --panel:rgba(23,26,31,.78);
  --panel-border:rgba(255,255,255,.08);
  --text:rgba(255,255,255,.92);
  --muted:rgba(255,255,255,.66);

  --dead:#2b2f33;
  --alive:#26c36a;
  --border:#0b0c0d;

  --btn:rgba(255,255,255,.09);
  --btn-hover:rgba(255,255,255,.13);
  --btn-active:rgba(255,255,255,.18);

  --shadow:0 12px 40px rgba(0,0,0,.45);
  --radius:16px;
}

*{box-sizing:border-box}
html,body{height:100%;margin:0;background:var(--bg);color:var(--text);
  font-family:ui-sans-serif,system-ui,-apple-system,Segoe UI,Roboto,Arial;
  overflow:hidden}
#life{position:fixed;inset:0;width:100vw;height:100vh;display:block;touch-action:none}

#ui{position:fixed;inset:0;pointer-events:none}

.panel{
  pointer-events:auto;
  background:var(--panel);
  border:1px solid var(--panel-border);
  border-radius:var(--radius);
  box-shadow:var(--shadow);
  backdrop-filter:blur(10px);
  -webkit-backdrop-filter:blur(10px);
}

.top-left{
  position:fixed;top:12px;left:12px;
  width:min(360px,calc(100vw - 24px));
  padding:14px 14px 12px;
}

.panel-header{
  display:flex;align-items:center;justify-content:space-between;gap:10px;
  margin-bottom:8px;
}

.panel-title{font-weight:650;letter-spacing:.2px;font-size:16px}

.icon-btn{
  border:1px solid var(--panel-border);
  background:rgba(255,255,255,.06);
  color:rgba(255,255,255,.92);
  width:34px;height:34px;
  border-radius:12px;
  cursor:pointer;
  display:grid;place-items:center;
  user-select:none;
  -webkit-tap-highlight-color:transparent;
  transition:background 120ms ease, transform 80ms ease;
}
.icon-btn:hover{background:rgba(255,255,255,.10)}
.icon-btn:active{background:rgba(255,255,255,.14);transform:translateY(1px)}
.chev{display:inline-block;transition:transform 140ms ease}
.panel.collapsed .chev{transform:rotate(-90deg)}
.panel.collapsed #panelBody{display:none}

.block{margin-top:12px}
.block-title{
  font-size:12px;color:var(--muted);
  margin-bottom:8px;letter-spacing:.25px;text-transform:uppercase;
}

.rules{display:grid;gap:12px}
.rules-group{display:grid;gap:8px}
.rules-row-label{font-size:12px;color:var(--muted)}

.rule-grid{
  display:grid;
  grid-template-columns:repeat(7, 1fr);
  gap:8px;
  width:100%;
}

.rule-btn{
  width:100%;
  aspect-ratio:1/1;
  border-radius:999px;
  border:1px solid rgba(0,0,0,.55);
  background:var(--dead);
  color:rgba(255,255,255,.9);
  font-weight:650;font-size:13px;line-height:1;
  cursor:pointer;
  display:grid;place-items:center;
  user-select:none;
  -webkit-tap-highlight-color:transparent;
}

.rule-btn.on,.rule-btn[aria-pressed="true"]{
  background:var(--alive);
  color:rgba(0,0,0,.88);
}
.rule-btn:disabled{opacity:.45;cursor:not-allowed}

.hint{margin-top:10px;font-size:12px;color:var(--muted);line-height:1.35}

.draw-controls{
  display:flex;align-items:center;gap:10px;
}
.draw-controls .switch{
  flex:1 1 auto;
  min-width:0;
}
.draw-controls #brushMode{
  flex:0 0 auto;
  width:auto;
  min-width:100px;
  max-width:140px;
  white-space:nowrap;
}

.switch{display:inline-flex;align-items:center;gap:10px;user-select:none;flex-shrink:0}
.switch input{position:absolute;opacity:0;pointer-events:none}
.switch-ui{
  width:44px;height:26px;border-radius:999px;
  border:1px solid var(--panel-border);
  background:rgba(255,255,255,.06);
  position:relative;transition:background 140ms ease;
  flex-shrink:0;
  display:flex;
  align-items:center;
  padding:3px;
  box-sizing:border-box;
}
.switch-ui::after{
  content:"";position:absolute;
  width:20px;height:20px;border-radius:999px;
  background:rgba(255,255,255,.88);
  transition:transform 140ms ease, background 140ms ease;
  left:3px;
  top:50%;
  transform:translateY(-50%);
}
.switch input:checked + .switch-ui{background:rgba(38,195,106,.28)}
.switch input:checked + .switch-ui::after{
  transform:translate(18px, -50%);
  background:var(--alive);
}
.switch-label{font-size:13px;color:rgba(255,255,255,.85);white-space:nowrap}

.file-controls{
  margin-top:10px;
  display:grid;
  grid-template-columns:repeat(3, 1fr);
  gap:10px;
  width:100%;
}

.btn{
  width:100%;
  border:1px solid var(--panel-border);
  background:var(--btn);
  color:rgba(255,255,255,.92);
  border-radius:12px;
  padding:10px 12px;
  font-size:13px;font-weight:600;
  cursor:pointer;
  transition:background 120ms ease, transform 80ms ease;
  user-select:none;
  -webkit-tap-highlight-color:transparent;
  text-align:center;
  display:flex;
  align-items:center;
  justify-content:center;
}
.btn:hover{background:var(--btn-hover)}
.btn:active{background:var(--btn-active);transform:translateY(1px)}
.btn-secondary{background:rgba(255,255,255,.06)}

.file-btn{position:relative;overflow:hidden}
.file-btn input{position:absolute;inset:0;opacity:0;cursor:pointer}

.stats{
  margin-top:10px;padding-top:10px;
  border-top:1px solid var(--panel-border);
  font-size:12px;color:var(--muted);
  line-height:1.45;
  white-space:pre-line;
}

.bottom-bar{
  pointer-events:auto;
  position:fixed;
  left:12px;right:12px;bottom:12px;
  padding:10px;
  display:grid;
  grid-template-columns:repeat(5, 1fr);
  gap:10px;
  background:var(--panel);
  border:1px solid var(--panel-border);
  border-radius:999px;
  box-shadow:var(--shadow);
  backdrop-filter:blur(10px);
  -webkit-backdrop-filter:blur(10px);
}

.speed{
  border:1px solid var(--panel-border);
  background:rgba(255,255,255,.08);
  color:rgba(255,255,255,.92);
  border-radius:999px;
  padding:12px 10px;
  font-size:13px;font-weight:700;
  cursor:pointer;
  user-select:none;
  -webkit-tap-highlight-color:transparent;
  transition:background 120ms ease;
}
.speed:hover{background:rgba(255,255,255,.12)}
.speed.active{
  background:rgba(38,195,106,.32);
  color:rgba(255,255,255,.95);
  border-color:rgba(38,195,106,.55);
}

@media (max-width:420px){
  .top-left{width:min(360px,calc(100vw - 24px))}
}