/* Brain Duel — dark futuristic UI, mobile first. */
:root {
  --bg: #070b14;
  --bg2: #0c1322;
  --panel: rgba(16, 24, 40, 0.72);
  --line: rgba(124, 243, 255, 0.16);
  --ink: #e9f4ff;
  --dim: #8fa3bd;
  --cyan: #7cf3ff;
  --violet: #b06bff;
  --good: #37e07a;
  --bad: #ff4d5e;
  --warn: #ffd23f;
  --radius: 16px;
  --shadow: 0 18px 60px rgba(0, 0, 0, 0.55);
}
* { box-sizing: border-box; -webkit-tap-highlight-color: transparent; }
html, body { height: 100%; }
body {
  margin: 0;
  background: radial-gradient(1200px 700px at 50% -10%, #16233c 0%, var(--bg) 55%, #04060c 100%);
  color: var(--ink);
  font-family: 'Segoe UI', system-ui, -apple-system, 'Helvetica Neue', Arial, sans-serif;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  touch-action: manipulation;
}
#fx { position: fixed; inset: 0; width: 100%; height: 100%; pointer-events: none; opacity: .55; z-index: 0; }
.app { position: relative; z-index: 1; min-height: 100%; display: flex; flex-direction: column; }
.screen { flex: 1; display: flex; flex-direction: column; padding: 18px 16px calc(18px + env(safe-area-inset-bottom)); max-width: 720px; width: 100%; margin: 0 auto; }
.mono { font-variant-numeric: tabular-nums; letter-spacing: .04em; }
.dim { color: var(--dim); }
.center { text-align: center; }
.grow { flex: 1; }
.hidden { display: none !important; }

/* ---------------------------------------------------------------- landing */
.brand { display: flex; align-items: center; gap: 10px; font-weight: 800; letter-spacing: .22em; font-size: 12px; color: var(--cyan); }
.brand .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--cyan); box-shadow: 0 0 14px var(--cyan); }
.hero { margin: auto 0; text-align: center; padding: 24px 0; }
.hero h1 {
  font-size: clamp(38px, 13vw, 74px); line-height: .95; margin: 0 0 14px;
  font-weight: 900; letter-spacing: .02em;
  background: linear-gradient(180deg, #ffffff, var(--cyan) 62%, #2b8fd6);
  -webkit-background-clip: text; background-clip: text; color: transparent;
  filter: drop-shadow(0 0 34px rgba(124, 243, 255, .22));
}
.hero .tag { font-size: clamp(14px, 4.4vw, 19px); color: var(--dim); letter-spacing: .06em; margin-bottom: 6px; }
.hero .sub { font-size: 13px; color: var(--dim); opacity: .8; margin-top: 10px; }
.invite { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: 16px; margin: 18px 0; box-shadow: var(--shadow); }
.invite .who { font-size: 18px; font-weight: 700; }
.invite .who b { color: var(--cyan); }
.invite .vs { color: var(--dim); font-size: 13px; margin-top: 4px; }

/* ------------------------------------------------------------------ buttons */
.btn {
  appearance: none; border: 1px solid var(--line); background: rgba(124, 243, 255, .06);
  color: var(--ink); font: inherit; font-weight: 700; letter-spacing: .1em; font-size: 13px;
  padding: 14px 18px; border-radius: 12px; cursor: pointer; transition: transform .12s ease, background .2s ease, border-color .2s ease;
  min-height: 48px;
}
.btn:active { transform: scale(.97); }
.btn.primary { background: linear-gradient(180deg, #9df7ff, var(--cyan)); color: #04121a; border-color: transparent; box-shadow: 0 10px 30px rgba(124, 243, 255, .25); }
.btn.ghost { background: transparent; }
.btn.wide { width: 100%; }
.btn.sm { padding: 10px 12px; font-size: 12px; min-height: 40px; }
.btn:disabled { opacity: .45; cursor: default; }
.row { display: flex; gap: 10px; flex-wrap: wrap; }
.row > * { flex: 1 1 0; min-width: 120px; }

/* ------------------------------------------------------------------- topbar */
.topbar { display: flex; align-items: center; gap: 12px; font-size: 11px; letter-spacing: .18em; color: var(--dim); }
.topbar .step { color: var(--cyan); font-weight: 700; }
.topbar .timer { margin-left: auto; font-weight: 700; color: var(--ink); font-variant-numeric: tabular-nums; }
.topbar .timer.low { color: var(--bad); }
.pbar { height: 4px; background: rgba(255, 255, 255, .08); border-radius: 4px; margin: 12px 0 4px; overflow: hidden; }
.pbar > i { display: block; height: 100%; width: 0; background: linear-gradient(90deg, var(--cyan), var(--violet)); transition: width .35s ease; }

/* -------------------------------------------------------------------- stage */
.stage { flex: 1; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 18px; padding: 10px 0; text-align: center; }
.prompt { font-size: clamp(15px, 4.6vw, 20px); font-weight: 700; letter-spacing: .02em; }
.hint { font-size: 12px; color: var(--dim); letter-spacing: .08em; }
.big { font-size: clamp(46px, 18vw, 96px); font-weight: 900; line-height: 1; }

/* reflex */
.reflex-pad { width: min(78vw, 340px); aspect-ratio: 1; border-radius: 50%; border: 2px solid var(--line); display: grid; place-items: center; background: radial-gradient(circle at 50% 40%, rgba(124,243,255,.06), transparent 70%); }
.reflex-pad.wait { animation: breathe 1.6s ease-in-out infinite; }
.reflex-pad.armed { border-color: rgba(255, 210, 63, .5); }
.reflex-pad.hit { border-color: var(--good); box-shadow: 0 0 60px rgba(55, 224, 122, .35); }
.reflex-pad.early { border-color: var(--bad); }
@keyframes breathe { 0%, 100% { transform: scale(1); opacity: .75; } 50% { transform: scale(1.03); opacity: 1; } }
.sym { font-size: clamp(64px, 26vw, 130px); line-height: 1; }
.sym.small { font-size: clamp(30px, 10vw, 46px); }

/* stream */
.stream { width: min(86vw, 420px); height: min(86vw, 420px); display: grid; place-items: center; border-radius: var(--radius); border: 1px solid var(--line); background: var(--panel); }
.stream .sym { animation: pop .18s ease; }
@keyframes pop { from { transform: scale(.86); opacity: .4; } to { transform: scale(1); opacity: 1; } }
.tapzone { width: min(86vw, 420px); min-height: 180px; border-radius: var(--radius); border: 1px dashed var(--line); display: grid; place-items: center; font-weight: 800; letter-spacing: .2em; color: var(--dim); user-select: none; }
.tapzone:active { background: rgba(124, 243, 255, .07); }

/* options */
.options { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; width: 100%; max-width: 460px; }
.options.one { grid-template-columns: 1fr; }
.opt { font-size: clamp(17px, 5.4vw, 22px); font-weight: 800; padding: 18px 10px; }
.opt.correct { border-color: var(--good); color: var(--good); }
.opt.wrong { border-color: var(--bad); color: var(--bad); }

/* sequence chips */
.seq { display: flex; gap: 8px; flex-wrap: wrap; justify-content: center; align-items: center; }
.chip { min-width: 46px; padding: 10px 12px; border-radius: 12px; border: 1px solid var(--line); background: var(--panel); font-weight: 800; font-size: clamp(17px, 5.4vw, 22px); }
.chip.q { color: var(--cyan); border-color: rgba(124, 243, 255, .5); }
.chip.picked { border-color: var(--cyan); }
.swatch { width: 46px; height: 46px; border-radius: 12px; border: 1px solid rgba(255, 255, 255, .18); }
.swatch.big { width: 62px; height: 62px; }

/* memory */
.mem-show { display: flex; gap: 10px; flex-wrap: wrap; justify-content: center; }
.mem-show .on { transform: scale(1.12); box-shadow: 0 0 30px rgba(124, 243, 255, .35); }
.grid { display: grid; gap: 8px; }
.cell { width: clamp(52px, 16vw, 74px); aspect-ratio: 1; border-radius: 12px; border: 1px solid var(--line); background: var(--panel); }
.cell.on { background: rgba(124, 243, 255, .55); border-color: var(--cyan); }
.cell.picked { border-color: var(--cyan); background: rgba(124, 243, 255, .18); }
.picks { display: flex; gap: 6px; justify-content: center; min-height: 26px; font-size: 20px; color: var(--cyan); }

/* ---------------------------------------------------------------- results */
.score-wrap { text-align: center; margin: 8px 0 4px; }
.score-label { font-size: 11px; letter-spacing: .3em; color: var(--dim); }
.score-big { font-size: clamp(64px, 24vw, 128px); font-weight: 900; line-height: 1; background: linear-gradient(180deg, #fff, var(--cyan) 60%, #2b8fd6); -webkit-background-clip: text; background-clip: text; color: transparent; }
.score-of { font-size: 12px; color: var(--dim); letter-spacing: .2em; }
.bars { width: 100%; margin: 14px 0; display: grid; gap: 8px; }
.bar { display: grid; grid-template-columns: 84px 1fr 46px; align-items: center; gap: 10px; font-size: 12px; letter-spacing: .08em; }
.bar .track { height: 8px; border-radius: 8px; background: rgba(255, 255, 255, .08); overflow: hidden; }
.bar .track > i { display: block; height: 100%; width: 0; background: linear-gradient(90deg, var(--cyan), var(--violet)); transition: width .8s cubic-bezier(.2, .8, .2, 1); }
.bar .val { text-align: right; font-weight: 700; font-variant-numeric: tabular-nums; }
.facts { display: flex; gap: 10px; flex-wrap: wrap; justify-content: center; margin: 6px 0 14px; }
.fact { background: var(--panel); border: 1px solid var(--line); border-radius: 12px; padding: 10px 14px; font-size: 12px; color: var(--dim); }
.fact b { display: block; color: var(--ink); font-size: 16px; margin-top: 2px; }
.compare { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: 14px; margin: 10px 0; text-align: center; }
.compare .win { font-size: 20px; font-weight: 800; }
.compare .win.good { color: var(--good); }
.compare .win.bad { color: var(--bad); }

/* share card */
.card { background: linear-gradient(160deg, #101a2e, #0a1120 60%, #131c33); border: 1px solid var(--line); border-radius: 20px; padding: 18px; box-shadow: var(--shadow); width: 100%; }
.card .card-top { display: flex; align-items: center; justify-content: space-between; font-size: 11px; letter-spacing: .28em; color: var(--cyan); font-weight: 800; }
.card .card-score { font-size: clamp(46px, 16vw, 74px); font-weight: 900; line-height: 1; margin: 10px 0 2px; }
.card .card-skills { display: flex; gap: 6px; flex-wrap: wrap; margin-top: 10px; }
.card .pill { font-size: 11px; letter-spacing: .1em; border: 1px solid var(--line); border-radius: 999px; padding: 5px 10px; color: var(--dim); }
.card .ask { margin-top: 12px; font-size: 13px; color: var(--dim); }
.name-row { display: flex; gap: 8px; margin: 12px 0 6px; }
input[type=text] { flex: 1; background: rgba(255, 255, 255, .05); border: 1px solid var(--line); color: var(--ink); border-radius: 12px; padding: 12px 14px; font: inherit; min-height: 48px; }
input[type=text]::placeholder { color: #5f7391; }

/* toast + flash */
.toast { position: fixed; left: 50%; bottom: 26px; transform: translateX(-50%) translateY(20px); background: rgba(10, 18, 32, .95); border: 1px solid var(--line); color: var(--ink); padding: 12px 18px; border-radius: 999px; font-size: 12px; letter-spacing: .1em; opacity: 0; transition: opacity .25s ease, transform .25s ease; z-index: 40; pointer-events: none; }
.toast.on { opacity: 1; transform: translateX(-50%) translateY(0); }
.flash { position: fixed; inset: 0; pointer-events: none; opacity: 0; transition: opacity .18s ease; z-index: 30; }
.flash.good { background: radial-gradient(circle at 50% 50%, rgba(55, 224, 122, .18), transparent 60%); opacity: 1; }
.flash.bad { background: radial-gradient(circle at 50% 50%, rgba(255, 77, 94, .18), transparent 60%); opacity: 1; }
.foot { text-align: center; font-size: 11px; color: #4d5f78; letter-spacing: .12em; padding-top: 14px; }
@media (max-width: 380px) { .bar { grid-template-columns: 70px 1fr 40px; } }
@media (prefers-reduced-motion: reduce) { * { animation: none !important; transition: none !important; } }