/* Morse Trainer — mobile-first dark UI */
:root {
  --bg: #0b1120;
  --bg2: #131c31;
  --card: #172136;
  --line: #26324d;
  --txt: #e8eefc;
  --muted: #8595b5;
  --accent: #38bdf8;
  --accent2: #22d3ee;
  --good: #34d399;
  --bad: #f87171;
  --ok: #fbbf24;
  --radius: 16px;
}
* { box-sizing: border-box; -webkit-tap-highlight-color: transparent; }
html, body { margin: 0; padding: 0; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, system-ui, sans-serif;
  background: radial-gradient(1200px 600px at 50% -10%, rgba(56,189,248,.10) 0%, transparent 60%), var(--bg);
  background-color: var(--bg);
  color: var(--txt);
  min-height: 100dvh;
  overscroll-behavior: none;
  padding-bottom: env(safe-area-inset-bottom);
}

/* screen-flash lamp */
#lamp { position: fixed; inset: 0; background: var(--accent); opacity: 0; pointer-events: none; transition: opacity .04s linear; z-index: 5; mix-blend-mode: screen; }
#lamp.on { opacity: .22; }

.topbar {
  display: flex; align-items: center; justify-content: space-between;
  padding: calc(env(safe-area-inset-top) + 12px) 18px 12px;
  position: sticky; top: 0; background: linear-gradient(var(--bg), rgba(11,17,32,.85)); z-index: 4;
  backdrop-filter: blur(6px);
}
.brand { font-weight: 700; letter-spacing: .3px; font-size: 18px; }
.brand .dot { color: var(--accent2); } .brand .dash { color: var(--accent); }
.streak { font-size: 14px; }
.muted { color: var(--muted); font-weight: 400; }

main { max-width: 560px; margin: 0 auto; padding: 12px 16px 96px; }
.tab { display: none; animation: fade .18s ease; }
.tab.active { display: block; }
@keyframes fade { from { opacity: 0; transform: translateY(4px); } to { opacity: 1; transform: none; } }

.card { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 16px; margin-bottom: 14px; }
.row { display: flex; align-items: center; }
.row.gap { gap: 10px; }
.row.wrap { flex-wrap: wrap; }
.row.spread { justify-content: space-between; text-align: center; }
.big { font-size: 30px; font-weight: 800; line-height: 1; }
.lbl { font-size: 11px; color: var(--muted); margin-top: 4px; text-transform: uppercase; letter-spacing: .5px; }
.pool { margin-top: 14px; font-size: 15px; color: var(--muted); }
.pool strong { color: var(--txt); letter-spacing: 3px; font-size: 17px; }

/* stage / play */
.stage { text-align: center; margin: 8px 0 18px; display: flex; flex-direction: column; align-items: center; gap: 10px; }
.status { color: var(--muted); min-height: 20px; font-size: 15px; }
.play-btn {
  border: none; cursor: pointer; color: #06121f; font-weight: 800; font-size: 20px;
  background: linear-gradient(135deg, var(--accent2), var(--accent));
  padding: 16px 40px; border-radius: 999px; box-shadow: 0 8px 24px rgba(56,189,248,.35);
  min-width: 180px;
}
.play-btn:active { transform: scale(.97); }

/* keypad (learn) */
.keypad { display: grid; grid-template-columns: repeat(auto-fill, minmax(58px, 1fr)); gap: 10px; margin-bottom: 16px; }
.key {
  aspect-ratio: 1/1; border-radius: 14px; border: 1px solid var(--line); background: var(--bg2);
  color: var(--txt); font-size: 24px; font-weight: 700; cursor: pointer; transition: transform .06s, background .15s;
}
.key:active { transform: scale(.94); }
.key.good { background: var(--good); color: #04170f; border-color: var(--good); }
.key.bad { background: var(--bad); color: #2a0606; border-color: var(--bad); }
.key.reveal { outline: 3px solid var(--good); outline-offset: -3px; }

/* buttons */
.btn { border: 1px solid var(--line); background: var(--bg2); color: var(--txt); padding: 13px 16px; border-radius: 12px; font-size: 15px; font-weight: 600; cursor: pointer; flex: 1; }
.btn:active { transform: scale(.98); }
.btn.primary { background: var(--accent); color: #06121f; border-color: var(--accent); }
.btn.primary:disabled { background: var(--bg2); color: var(--muted); border-color: var(--line); cursor: default; }
.btn.ghost { background: transparent; }
.btn.danger { background: transparent; color: var(--bad); border-color: var(--bad); width: 100%; }
.btn.small { flex: 0 0 auto; padding: 10px 14px; font-size: 14px; }

.hint { color: var(--muted); font-size: 13px; line-height: 1.5; margin: 14px 2px 0; }
.hint.center { text-align: center; }
.hint em { color: var(--txt); font-style: normal; text-decoration: underline; text-decoration-color: var(--line); }

/* fields */
.field { display: flex; flex-direction: column; gap: 6px; font-size: 12px; color: var(--muted); text-transform: uppercase; letter-spacing: .5px; }
select, .copy-input { background: var(--bg2); color: var(--txt); border: 1px solid var(--line); border-radius: 10px; padding: 12px; font-size: 16px; }
select { min-width: 130px; }
.copy-input { width: 100%; text-transform: uppercase; letter-spacing: 4px; font-size: 22px; text-align: center; margin-bottom: 12px; }
.copy-input:focus, select:focus { outline: 2px solid var(--accent); border-color: var(--accent); }

.result { font-weight: 700; font-size: 16px; padding: 0 6px; }
.result.good { color: var(--good); } .result.ok { color: var(--ok); } .result.bad { color: var(--bad); }
.answer-line { margin-top: 12px; color: var(--muted); font-size: 15px; }
.answer-line span { color: var(--accent2); letter-spacing: 3px; font-weight: 700; }

/* send */
.decoded-box { text-align: center; }
.decoded { font-size: 30px; font-weight: 800; letter-spacing: 6px; min-height: 40px; word-break: break-word; }
.symbols { font-size: 26px; color: var(--accent2); letter-spacing: 4px; min-height: 30px; }
.key-pad {
  width: 100%; height: 180px; border-radius: 20px; border: 1px solid var(--line);
  background: radial-gradient(circle at 50% 40%, #1e2b47, #121a2c); color: var(--txt);
  font-size: 26px; font-weight: 800; letter-spacing: 4px; cursor: pointer; margin-bottom: 12px;
  touch-action: none; user-select: none;
}
.key-pad:active { background: radial-gradient(circle at 50% 40%, #26507a, #16233c); }

/* reference */
#ref-wrap h3 { color: var(--muted); font-size: 13px; text-transform: uppercase; letter-spacing: 1px; margin: 20px 4px 10px; }
.ref-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(84px, 1fr)); gap: 8px; }
.ref-cell { display: flex; flex-direction: column; align-items: center; gap: 4px; padding: 12px 6px; background: var(--card); border: 1px solid var(--line); border-radius: 12px; cursor: pointer; }
.ref-cell:active { background: var(--bg2); }
.ref-ch { font-size: 20px; font-weight: 700; }
.ref-code { font-size: 15px; color: var(--accent2); letter-spacing: 2px; }

/* settings */
.slider { display: block; font-size: 14px; margin-bottom: 18px; color: var(--muted); }
.slider span { float: right; color: var(--txt); font-weight: 700; }
.slider input { width: 100%; margin-top: 10px; accent-color: var(--accent); height: 26px; }
.toggle { display: flex; align-items: center; gap: 12px; padding: 12px 0; font-size: 16px; border-bottom: 1px solid var(--line); }
.toggle:last-child { border-bottom: none; }
.toggle input { width: 22px; height: 22px; accent-color: var(--accent); }

/* nav */
.nav {
  position: fixed; bottom: 0; left: 0; right: 0; display: flex; justify-content: space-around;
  background: rgba(19,28,49,.92); backdrop-filter: blur(10px); border-top: 1px solid var(--line);
  padding: 6px 4px calc(env(safe-area-inset-bottom) + 6px); z-index: 4;
}
.nav-btn { flex: 1; background: none; border: none; color: var(--muted); font-size: 11px; font-weight: 600; display: flex; flex-direction: column; align-items: center; gap: 3px; cursor: pointer; padding: 6px 0; }
.nav-btn span { font-size: 20px; }
.nav-btn.active { color: var(--accent); }

/* toast */
.toast {
  position: fixed; left: 50%; bottom: 84px; transform: translateX(-50%) translateY(20px);
  background: var(--accent); color: #06121f; font-weight: 700; padding: 12px 20px; border-radius: 999px;
  opacity: 0; pointer-events: none; transition: all .25s; z-index: 10; max-width: 90%; text-align: center;
}
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

@media (min-width: 480px) { .key { font-size: 26px; } }