:root {
  --bg: #0f1117;
  --bg-soft: #171a23;
  --surface: #1e2230;
  --surface-2: #262b3d;
  --border: #333a52;
  --text: #eef0f6;
  --text-dim: #9aa3ba;
  --correct: #57ac5c;
  --present: #ceb02c;
  --absent: #3a3f52;
  --accent: #7aa2ff;
  --accent-2: #b07aff;
  --danger: #e2554f;
  --radius: 12px;
  --key-h: 52px;
  font-size: 16px;
}

* { box-sizing: border-box; margin: 0; padding: 0; -webkit-tap-highlight-color: transparent; }

.hidden { display: none !important; }

html, body { height: 100%; touch-action: manipulation; }

body {
  background: radial-gradient(1200px 600px at 50% -10%, #1a2036 0%, var(--bg) 55%);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  user-select: none;
}

/* ---------- top bar ---------- */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 14px;
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}
.topbar-left, .topbar-right { display: flex; gap: 8px; min-width: 90px; }
.topbar-right { justify-content: flex-end; }

.logo {
  font-size: 1.5rem;
  letter-spacing: 0.35em;
  font-weight: 800;
  color: var(--text);
  text-indent: 0.35em;
}
.logo span { color: var(--correct); }

.icon-btn {
  width: 38px; height: 38px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-dim);
  font-size: 1.05rem;
  font-weight: 700;
  cursor: pointer;
  transition: transform 0.15s, background 0.2s, color 0.2s;
}
.icon-btn:hover { background: var(--surface-2); color: var(--text); transform: translateY(-1px); }

/* ---------- mode switch ---------- */
.mode-switch {
  display: flex;
  gap: 8px;
  justify-content: center;
  padding: 10px 0 4px;
  flex-shrink: 0;
}
.mode-btn {
  display: flex; flex-direction: column; align-items: center; gap: 1px;
  padding: 7px 22px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-dim);
  font-weight: 700;
  font-size: 0.9rem;
  cursor: pointer;
  transition: all 0.25s;
}
.mode-btn small { font-weight: 400; font-size: 0.65rem; opacity: 0.75; }
.mode-btn.active {
  background: linear-gradient(135deg, rgba(87,172,92,0.25), rgba(122,162,255,0.25));
  border-color: var(--correct);
  color: var(--text);
  box-shadow: 0 0 18px rgba(87,172,92,0.25);
}

.results-btn {
  display: flex; flex-direction: column; align-items: center; gap: 1px;
  padding: 7px 16px;
  border-radius: 999px;
  border: 1px solid var(--present);
  background: rgba(206,176,44,0.15);
  color: var(--text);
  font-weight: 700;
  font-size: 0.9rem;
  cursor: pointer;
  transition: all 0.25s;
  animation: pop 0.3s ease;
}
.results-btn small { font-weight: 400; font-size: 0.65rem; opacity: 0.75; }
.results-btn:hover { box-shadow: 0 0 14px rgba(206,176,44,0.3); }
.results-btn.hidden { display: none; }

/* ---------- game area ---------- */
.game-area {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow-y: auto;
  padding: 10px;
  min-height: 0;
  overscroll-behavior: contain;
  scroll-padding-block: 14px;
}
.game-area.mode-quad {
  align-items: flex-start;
  padding-top: 14px;
  padding-bottom: 16px;
}
.loading { color: var(--text-dim); animation: pulse 1.2s ease-in-out infinite; }
@keyframes pulse { 50% { opacity: 0.4; } }

.boards { display: grid; gap: 14px; margin: auto 0; }
.boards.mode-six { grid-template-columns: 1fr; }
.boards.mode-quad {
  grid-template-columns: 1fr 1fr;
  gap: 10px 18px;
  margin: 0 0 10px;
}

.board {
  display: grid;
  gap: 5px;
  padding: 8px;
  border-radius: var(--radius);
  background: rgba(255,255,255,0.02);
  transition: opacity 0.5s, filter 0.5s;
}
.board.solved { opacity: 0.55; filter: saturate(0.8); }
.board.failed .tile.filled { border-color: var(--danger); }

.row { display: flex; gap: 5px; justify-content: center; }

.tile {
  width: var(--tile, 56px);
  height: var(--tile, 56px);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: calc(var(--tile, 56px) * 0.5);
  font-weight: 800;
  border: 2px solid var(--border);
  border-radius: 8px;
  background: transparent;
  color: var(--text);
  transition: border-color 0.15s;
}
.boards.mode-quad .tile {
  --tile: clamp(28px, calc((100dvh - 312px) / 18), 34px);
  border-radius: 6px;
  border-width: 1.5px;
}

.tile.typed { border-color: var(--text-dim); animation: pop 0.12s ease; }
@keyframes pop { 50% { transform: scale(1.12); } }

.tile.reveal { animation: flip 0.5s ease forwards; }
@keyframes flip {
  0% { transform: rotateX(0); }
  49% { transform: rotateX(90deg); }
  51% { transform: rotateX(90deg); }
  100% { transform: rotateX(0); }
}

.tile.correct { background: var(--correct); border-color: var(--correct); color: #fff; }
.tile.present { background: var(--present); border-color: var(--present); color: #fff; }
.tile.absent  { background: var(--absent);  border-color: var(--absent);  color: #cfd3e0; }

.row.shake { animation: shake 0.45s; }
@keyframes shake {
  10%, 90% { transform: translateX(-2px); }
  20%, 80% { transform: translateX(4px); }
  30%, 70% { transform: translateX(-6px); }
  40%, 60% { transform: translateX(6px); }
  50% { transform: translateX(-4px); }
}

.row.bounce .tile { animation: bounce 0.7s ease; }
@keyframes bounce {
  0%, 100% { transform: translateY(0); }
  35% { transform: translateY(-14px); }
  60% { transform: translateY(3px); }
}

/* ---------- keyboard ---------- */
.keyboard {
  position: relative;
  z-index: 5;
  flex-shrink: 0;
  padding: 6px 6px calc(8px + env(safe-area-inset-bottom));
  max-width: 560px;
  width: 100%;
  margin: 0 auto;
  background: linear-gradient(180deg, rgba(15,17,23,0.92), var(--bg) 18%);
  border-top: 1px solid rgba(51,58,82,0.55);
}
.kb-row { display: flex; gap: 5px; justify-content: center; margin-bottom: 6px; }

.key {
  position: relative;
  flex: 1;
  max-width: 46px;
  height: var(--key-h);
  border: none;
  border-radius: 6px;
  background: var(--surface-2);
  color: var(--text);
  font-size: 0.95rem;
  font-weight: 700;
  cursor: pointer;
  overflow: hidden;
  transition: transform 0.08s, filter 0.15s;
  touch-action: manipulation;
}
.key:active { transform: scale(0.92); filter: brightness(1.3); }
.key.wide { max-width: 72px; flex: 1.6; font-size: 0.7rem; }
.key span.kb-label { position: relative; z-index: 2; }

.key.correct { background: var(--correct); }
.key.present { background: var(--present); }
.key.absent { background: #23273a; color: #5d6479; }

/* quad mode: 4 quadrants per key */
.key .quad {
  position: absolute;
  width: 50%; height: 50%;
  z-index: 1;
  background: transparent;
}
.key .quad.q0 { top: 0; left: 0; }
.key .quad.q1 { top: 0; right: 0; }
.key .quad.q2 { bottom: 0; left: 0; }
.key .quad.q3 { bottom: 0; right: 0; }
.key .quad.correct { background: var(--correct); }
.key .quad.present { background: var(--present); }
.key.all-absent { background: #23273a; color: #5d6479; }

/* ---------- toast ---------- */
.toast-wrap {
  position: fixed;
  top: 70px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 300;
  display: flex;
  flex-direction: column;
  gap: 8px;
  align-items: center;
  pointer-events: none;
}
.toast {
  background: var(--text);
  color: var(--bg);
  font-weight: 700;
  padding: 10px 18px;
  border-radius: 8px;
  animation: toast-in 0.2s ease;
  box-shadow: 0 8px 24px rgba(0,0,0,0.4);
}
.toast.fade { opacity: 0; transition: opacity 0.4s; }
@keyframes toast-in { from { opacity: 0; transform: translateY(-8px); } }

/* ---------- modal ---------- */
.modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(5,7,12,0.72);
  backdrop-filter: blur(3px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 200;
  animation: fade-in 0.2s;
}
@keyframes fade-in { from { opacity: 0; } }
.modal-backdrop.hidden { display: none; }

.modal {
  position: relative;
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: 16px;
  width: min(440px, calc(100vw - 28px));
  max-height: 84vh;
  overflow-y: auto;
  padding: 26px 24px 22px;
  animation: modal-in 0.25s cubic-bezier(0.2, 1.4, 0.5, 1);
  box-shadow: 0 24px 60px rgba(0,0,0,0.5);
}
@keyframes modal-in { from { opacity: 0; transform: translateY(18px) scale(0.97); } }

.modal-close {
  position: absolute;
  top: 10px; right: 12px;
  background: none; border: none;
  color: var(--text-dim);
  font-size: 1.6rem;
  cursor: pointer;
  line-height: 1;
}
.modal h2 { margin-bottom: 14px; font-size: 1.15rem; letter-spacing: 0.06em; text-transform: uppercase; }
.modal h3 { margin: 16px 0 8px; font-size: 0.85rem; color: var(--text-dim); text-transform: uppercase; letter-spacing: 0.08em; }
.modal p { color: var(--text-dim); font-size: 0.92rem; line-height: 1.55; margin-bottom: 10px; }
.modal p strong { color: var(--text); }

/* help demo tiles */
.demo-row { display: flex; gap: 4px; margin: 8px 0 4px; }
.demo-row .tile { --tile: 38px; font-size: 1.05rem; }

/* forms */
.form-tabs { display: flex; gap: 6px; margin-bottom: 16px; }
.form-tabs button {
  flex: 1; padding: 9px;
  border-radius: 8px; border: 1px solid var(--border);
  background: transparent; color: var(--text-dim);
  font-weight: 700; cursor: pointer;
}
.form-tabs button.active { background: var(--surface-2); color: var(--text); border-color: var(--accent); }

.field { margin-bottom: 12px; }
.field label { display: block; font-size: 0.75rem; color: var(--text-dim); margin-bottom: 5px; text-transform: uppercase; letter-spacing: 0.06em; }
.field input {
  width: 100%;
  padding: 11px 12px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  font-size: 1rem;
}
.field input:focus { outline: none; border-color: var(--accent); }

.btn {
  display: inline-block;
  width: 100%;
  padding: 12px;
  border-radius: 10px;
  border: none;
  background: linear-gradient(135deg, var(--correct), #3f8d47);
  color: #fff;
  font-size: 1rem;
  font-weight: 800;
  cursor: pointer;
  transition: transform 0.12s, filter 0.2s;
}
.btn:hover { filter: brightness(1.1); transform: translateY(-1px); }
.btn.secondary { background: var(--surface-2); color: var(--text); border: 1px solid var(--border); }
.btn.small { width: auto; padding: 8px 14px; font-size: 0.8rem; }

.form-error { color: var(--danger); font-size: 0.85rem; min-height: 18px; margin-bottom: 8px; }

/* stats */
.stat-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; margin-bottom: 6px; }
.stat-cell { text-align: center; background: var(--surface); border-radius: 10px; padding: 10px 4px; }
.stat-cell .num { font-size: 1.5rem; font-weight: 800; }
.stat-cell .lbl { font-size: 0.62rem; color: var(--text-dim); text-transform: uppercase; letter-spacing: 0.05em; }

.dist-row { display: flex; align-items: center; gap: 8px; margin-bottom: 5px; }
.dist-row .g { width: 14px; font-size: 0.8rem; color: var(--text-dim); text-align: right; }
.dist-bar {
  height: 20px;
  background: var(--absent);
  border-radius: 4px;
  min-width: 24px;
  display: flex;
  align-items: center;
  justify-content: flex-end;
  padding-right: 7px;
  font-size: 0.75rem;
  font-weight: 700;
  transition: width 0.6s ease;
}
.dist-bar.hot { background: var(--correct); }

/* leaderboard */
.lb-table { width: 100%; border-collapse: collapse; font-size: 0.92rem; }
.lb-table th { text-align: left; color: var(--text-dim); font-size: 0.7rem; text-transform: uppercase; letter-spacing: 0.06em; padding: 6px 8px; }
.lb-table td { padding: 9px 8px; border-top: 1px solid var(--border); }
.lb-table tr.me td { color: var(--accent); font-weight: 700; }
.lb-rank { width: 34px; color: var(--text-dim); }
.lb-rank.top { font-size: 1.05rem; }

/* result modal */
.result-answers { display: flex; flex-wrap: wrap; gap: 8px; margin: 10px 0 4px; }
.result-answers .ans {
  padding: 7px 12px;
  border-radius: 8px;
  background: var(--surface-2);
  font-weight: 800;
  letter-spacing: 0.15em;
}
.result-answers .ans.hit { background: var(--correct); color: #fff; }
.countdown { font-variant-numeric: tabular-nums; font-size: 1.6rem; font-weight: 800; letter-spacing: 0.06em; }
.result-score { font-size: 2.2rem; font-weight: 800; color: var(--correct); }
.save-callout {
  display: grid;
  gap: 8px;
  margin: 14px 0 4px;
  padding: 12px;
  border: 1px solid rgba(122,162,255,0.45);
  border-radius: 10px;
  background: rgba(122,162,255,0.1);
}
.save-callout span {
  color: var(--text-dim);
  font-size: 0.86rem;
  line-height: 1.35;
}
.save-callout .btn { margin-top: 2px; }

/* account */
.account-user { display: flex; align-items: center; gap: 12px; margin-bottom: 18px; }
.avatar {
  width: 44px; height: 44px; border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  display: flex; align-items: center; justify-content: center;
  font-weight: 800; font-size: 1.2rem; color: #fff;
}

#confetti-canvas {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 400;
}

/* small screens */
@media (max-height: 720px) {
  :root { --key-h: 46px; }
  .mode-switch { padding-top: 8px; }
  .mode-btn,
  .results-btn { padding-top: 6px; padding-bottom: 6px; }
  .game-area.mode-quad { padding-top: 12px; padding-bottom: 14px; }
  .tile { --tile: 48px; }
  .boards.mode-quad .tile { --tile: clamp(24px, calc((100dvh - 296px) / 18), 30px); }
  .board { gap: 4px; padding: 5px; }
}
@media (max-width: 420px) {
  .game-area { padding-inline: 6px; }
  .boards.mode-quad { gap: 8px 10px; }
  .boards.mode-quad .tile { --tile: clamp(24px, calc((100dvh - 304px) / 18), 28px); }
  .tile { --tile: 50px; }
}