/* ============================================================
   SHINGLES — symmetric number pyramid — styles
   ============================================================ */
:root{
  --bg0:#0b0d1f;
  --bg1:#141833;
  --bg2:#1c2145;
  --ink:#eef1ff;
  --ink-dim:#9aa2cc;
  --line:rgba(255,255,255,.10);
  --card:rgba(255,255,255,.05);
  --accent:#7c9cff;
  --accent2:#ff8bd0;
  --good:#4ade80;
  --bad:#ff5a72;
  --warn:#fbbf24;
  --wood:#c68b52;
  --wood-d:#9a6636;
  --cell:52px;
  --gap:8px;
  --tab-w:calc(var(--cell) * 0.82);   /* row-total column: narrow (number only, no "=") to free width */
  --radius:16px;
  --shadow:0 18px 40px rgba(0,0,0,.45);
  --font:'Segoe UI',system-ui,-apple-system,Roboto,Helvetica,Arial,sans-serif;
}

*{box-sizing:border-box;-webkit-tap-highlight-color:transparent;}
html,body{height:100%;margin:0;overscroll-behavior:none;}
body{
  font-family:var(--font);color:var(--ink);
  background:
    radial-gradient(1200px 800px at 20% -10%, #2a2166 0%, transparent 55%),
    radial-gradient(1000px 700px at 110% 20%, #1b3a5e 0%, transparent 55%),
    linear-gradient(160deg, var(--bg0), var(--bg1) 60%, #0a0b18);
  overflow:hidden;user-select:none;touch-action:manipulation;
  -webkit-user-select:none;-webkit-touch-callout:none;
}
button{touch-action:manipulation;}
.c-good{color:var(--good);}

#fx{position:fixed;inset:0;width:100%;height:100%;pointer-events:none;z-index:5;}
#app{position:relative;z-index:2;height:100vh;height:100dvh;}

/* ---------- screens ---------- */
.screen{position:absolute;inset:0;display:none;flex-direction:column;align-items:center;
  padding:calc(10px + env(safe-area-inset-top)) calc(12px + env(safe-area-inset-right))
          calc(10px + env(safe-area-inset-bottom)) calc(12px + env(safe-area-inset-left));
  animation:fadeIn .35s ease both;}
#screen-game{padding-top:calc(8px + env(safe-area-inset-top));padding-bottom:calc(8px + env(safe-area-inset-bottom));}
.screen.is-active{display:flex;}
@keyframes fadeIn{from{opacity:0;transform:translateY(8px);}to{opacity:1;transform:none;}}
.screen-title{font-size:clamp(18px,4vw,26px);letter-spacing:.22em;margin:6vh 0 4vh;font-weight:800;}

/* ---------- title ---------- */
.title-wrap{margin:auto;text-align:center;display:flex;flex-direction:column;align-items:center;gap:18px;max-width:560px;}
.logo{display:flex;gap:8px;margin-bottom:6px;flex-wrap:wrap;justify-content:center;}
.logo-shingle{display:grid;place-items:center;width:clamp(34px,9vw,58px);height:clamp(42px,11vw,70px);
  font-size:clamp(20px,5vw,34px);font-weight:900;color:#fff;border-radius:12px;
  background:linear-gradient(160deg,#d79a5c,#a76b38);
  box-shadow:inset 0 2px 0 rgba(255,255,255,.4), inset 0 -6px 12px rgba(0,0,0,.25), 0 10px 20px rgba(90,50,20,.5);
  transform:rotate(-3deg);animation:logoDrop .6s cubic-bezier(.2,1.3,.4,1) both;animation-delay:calc(var(--i)*.06s);}
.logo-shingle:nth-child(even){background:linear-gradient(160deg,#8a7dff,#5a63d8);transform:rotate(3deg);}
@keyframes logoDrop{from{opacity:0;transform:translateY(-40px) rotate(-14deg);}to{opacity:1;}}
.tagline{color:var(--ink-dim);font-size:15px;line-height:1.5;max-width:46ch;margin:4px 0 8px;}
.best-line{color:var(--ink-dim);font-size:13px;letter-spacing:.04em;min-height:20px;margin-top:10px;
  display:flex;flex-wrap:wrap;gap:6px 8px;justify-content:center;align-items:center;max-width:340px;}
.best-line b{color:var(--warn);font-variant-numeric:tabular-nums;}
.best-head{width:100%;font-size:11px;letter-spacing:.18em;color:var(--ink-dim);opacity:.7;}
.best-item{display:inline-flex;align-items:center;gap:6px;padding:5px 10px;border-radius:999px;
  background:rgba(255,255,255,.05);border:1px solid var(--line);}
.best-diff{font-weight:800;letter-spacing:.05em;font-size:11px;color:var(--ink);}
.best-round{color:var(--accent2);opacity:.9;font-size:11px;}

/* ---------- buttons ---------- */
.btn{font-family:inherit;font-weight:800;letter-spacing:.06em;border:none;border-radius:14px;cursor:pointer;
  padding:13px 22px;font-size:15px;color:#fff;background:var(--card);border:1px solid var(--line);
  transition:transform .12s ease, box-shadow .12s ease, background .2s;}
.btn:hover{transform:translateY(-2px);}
.btn:active{transform:translateY(1px) scale(.98);}
.btn-primary{background:linear-gradient(160deg,#8a7dff,#5a63d8);border:none;
  box-shadow:0 10px 24px rgba(90,70,220,.45), inset 0 1px 0 rgba(255,255,255,.4);}
.btn-lg{padding:16px 46px;font-size:19px;letter-spacing:.14em;}
.btn-ghost{background:transparent;border:1px solid var(--line);color:var(--ink-dim);}
.btn-ghost:hover{color:#fff;}

/* ---------- difficulty ---------- */
.diff-grid{display:flex;flex-direction:column;gap:14px;width:min(420px,92vw);margin:auto 0;}
.diff-card{text-align:left;display:flex;flex-direction:column;gap:4px;position:relative;padding:20px 22px;
  border-radius:var(--radius);cursor:pointer;color:#fff;background:var(--card);border:1px solid var(--line);
  transition:transform .14s ease, box-shadow .14s ease, border-color .2s;font-family:inherit;}
.diff-card:hover{transform:translateY(-3px) scale(1.01);border-color:var(--accent);box-shadow:var(--shadow);}
.diff-name{font-size:22px;font-weight:900;letter-spacing:.1em;}
.diff-desc{color:var(--ink-dim);font-size:14px;}
.diff-dots{position:absolute;right:20px;top:22px;display:flex;gap:5px;}
.diff-dots i{width:9px;height:9px;border-radius:50%;background:var(--accent2);opacity:.85;}
.diff-card.diff-timed{background:linear-gradient(160deg, rgba(103,232,249,.14), rgba(255,139,208,.10));border-color:rgba(103,232,249,.45);}
.diff-card.diff-timed .diff-name{background:linear-gradient(90deg,#67e8f9,#ff8bd0);-webkit-background-clip:text;background-clip:text;color:transparent;}
.diff-card.diff-timed .diff-dots i{background:#67e8f9;}
/* countdown urgency */
.hud-stat.low .hud-val{color:var(--bad);animation:timePulse .5s ease-in-out infinite;}
.hud-stat.low .hud-label{color:var(--bad);}
@keyframes timePulse{0%,100%{transform:scale(1);}50%{transform:scale(1.18);}}
#btn-diff-back{margin-top:18px;}

/* ---------- HUD ---------- */
.hud{width:min(720px,100%);display:flex;align-items:center;gap:10px;padding:10px 12px;border-radius:16px;
  background:var(--card);border:1px solid var(--line);backdrop-filter:blur(8px);margin-bottom:10px;}
.hud-stat{display:flex;flex-direction:column;align-items:center;gap:1px;flex:1;min-width:0;}
.hud-label{font-size:10px;letter-spacing:.14em;color:var(--ink-dim);}
.hud-val{font-size:19px;font-weight:900;font-variant-numeric:tabular-nums;}
.hud-lives .hud-val{letter-spacing:1px;font-size:16px;}
.hud-btn{width:40px;height:40px;flex:none;border-radius:12px;font-size:18px;color:#fff;cursor:pointer;
  background:rgba(255,255,255,.06);border:1px solid var(--line);}
.hud-btn:active{transform:scale(.92);}
.heart{filter:drop-shadow(0 2px 3px rgba(0,0,0,.4));}
.heart.lost{opacity:.22;filter:grayscale(1);}

/* ---------- in-game brand (tiled logo, compact, always horizontal) ---------- */
.game-logo{display:flex;flex-direction:row;flex-wrap:nowrap;gap:5px;justify-content:center;align-items:center;
  width:100%;margin:2px 0 6px;}
.game-logo .logo-shingle{flex:0 0 auto;width:24px;height:29px;font-size:16px;border-radius:7px;
  animation:none;box-shadow:inset 0 1px 0 rgba(255,255,255,.4), inset 0 -3px 7px rgba(0,0,0,.25), 0 4px 9px rgba(90,50,20,.4);}

/* ---------- rule banner ---------- */
.rule-banner{width:min(720px,100%);display:flex;align-items:center;justify-content:center;gap:10px;
  margin-bottom:8px;font-size:13px;color:var(--ink-dim);flex-wrap:wrap;}
.rule-pill{font-weight:900;letter-spacing:.05em;color:#0b0d1f;padding:8px 20px;border-radius:999px;font-size:18px;}

/* new-variation modal (rendered inside .overlay-card) */
.ci-tag{display:inline-block;font-size:11px;font-weight:900;letter-spacing:.14em;color:#0b0d1f;padding:3px 12px;border-radius:999px;margin-bottom:10px;}
.ci-body{font-size:16px;color:var(--ink);line-height:1.45;margin-bottom:14px;}
.ci-body b{color:#ffe0a8;}
.ci-nums{display:flex;gap:8px;justify-content:center;flex-wrap:wrap;margin-bottom:14px;}
.ci-num{width:42px;height:42px;border-radius:11px;display:grid;place-items:center;font-weight:900;font-size:20px;color:#fff;
  background:linear-gradient(180deg,#8a7dff,#5a63d8);box-shadow:inset 0 1px 0 rgba(255,255,255,.35), 0 4px 10px rgba(60,40,140,.35);
  animation:pop .3s ease both;}
.ci-num:nth-child(2){animation-delay:.05s;} .ci-num:nth-child(3){animation-delay:.1s;}
.ci-num:nth-child(4){animation-delay:.15s;} .ci-num:nth-child(5){animation-delay:.2s;}
.ci-note{font-size:13px;color:var(--ink-dim);line-height:1.4;margin-bottom:16px;}
.ci-dsa{display:flex;align-items:center;justify-content:center;gap:8px;margin-top:12px;font-size:13px;color:var(--ink-dim);cursor:pointer;}
.ci-dsa input{width:18px;height:18px;accent-color:var(--accent);}

/* ---------- stage / pyramid ---------- */
.board-scroll{width:100%;flex:1;min-height:0;overflow:auto;overscroll-behavior:contain;-webkit-overflow-scrolling:touch;
  display:flex;justify-content:center;align-items:center;padding:6px 0;}
.stage{display:flex;flex-direction:column;align-items:stretch;transform-origin:top center;}
.pyramid{display:flex;flex-direction:column;align-items:stretch;gap:var(--gap);}

/* each row: centered cells (flex:1) + a fixed total tab, so all totals line up in a right column */
.prow{display:flex;align-items:center;gap:var(--gap);animation:rowIn .4s cubic-bezier(.2,1.1,.4,1) both;}
@keyframes rowIn{from{opacity:0;transform:translateY(-14px);}to{opacity:1;transform:none;}}
.prow-cells{flex:1;display:flex;align-items:center;justify-content:center;gap:var(--gap);}

/* row target tab — a single aligned column on the right of the pyramid */
.sumtab{flex:none;width:var(--tab-w);height:calc(var(--cell) * .72);border-radius:10px;
  display:flex;align-items:center;justify-content:center;gap:1px;padding:0 3px;
  font-weight:900;font-size:calc(var(--cell) * .40);color:#3a2408;font-variant-numeric:tabular-nums;
  background:linear-gradient(180deg,#ffd27a,#f0a63a);
  box-shadow:inset 0 2px 0 rgba(255,255,255,.55), inset 0 -4px 8px rgba(0,0,0,.18);}
.sumtab.ghost{visibility:hidden;}
.sumtab.hidden{background:repeating-linear-gradient(135deg,#3a2b52,#3a2b52 6px,#33254a 6px,#33254a 12px);
  color:#c9bfe6;border:1px dashed rgba(255,255,255,.25);box-shadow:none;}
.prow.done .sumtab{background:linear-gradient(180deg,#8effb0,#3fd07a);color:#06210f;border:none;}
.prow.done .sumtab.hidden{animation:revealTab .5s ease;}
@keyframes revealTab{0%{transform:scale(.7) rotate(-8deg);}60%{transform:scale(1.12);}100%{transform:scale(1);}}
.sum-spacer{flex:none;width:6px;}

/* cells */
.cell{flex:none;width:var(--cell);height:var(--cell);border-radius:12px;display:grid;place-items:center;
  font-size:calc(var(--cell) * .56);font-weight:900;color:#fff;position:relative;
  transition:transform .1s ease, border-color .15s, background .15s, box-shadow .15s;}
.cell.blank{cursor:pointer;background:linear-gradient(180deg, rgba(255,255,255,.09), rgba(255,255,255,.02));
  border:2px solid var(--line);box-shadow:inset 0 2px 6px rgba(0,0,0,.28);color:#fff;}
.cell.blank:hover{border-color:rgba(255,255,255,.3);}
.cell.given{background:linear-gradient(180deg,#c68b52,#9a6636);border:2px solid rgba(255,235,205,.35);
  color:#fff6e9;box-shadow:inset 0 2px 0 rgba(255,255,255,.35), 0 5px 10px rgba(70,40,15,.4);}
.cell.filled{background:linear-gradient(180deg,#8a7dff,#5a63d8);border:2px solid rgba(255,255,255,.35);
  color:#fff;box-shadow:inset 0 2px 0 rgba(255,255,255,.35), 0 6px 12px rgba(60,40,140,.35);animation:pop .18s ease;}
@keyframes pop{0%{transform:scale(.6);}70%{transform:scale(1.12);}100%{transform:scale(1);}}
.cell.sel{border-color:var(--accent)!important;box-shadow:0 0 0 3px rgba(124,156,255,.4), inset 0 2px 6px rgba(0,0,0,.25)!important;transform:translateY(-2px);}
.prow.done .cell{background:linear-gradient(180deg,#4ade80,#22b463)!important;border-color:rgba(255,255,255,.4)!important;color:#06210f!important;
  box-shadow:inset 0 2px 0 rgba(255,255,255,.5), 0 6px 12px rgba(30,150,80,.35)!important;}
/* victory celebration: a golden shimmer ripples row-by-row, then the whole pyramid bounces */
@keyframes winPop{0%{transform:scale(1);}35%{transform:scale(1.13);}100%{transform:scale(1);}}
@keyframes cellGlow{0%,100%{box-shadow:inset 0 2px 0 rgba(255,255,255,.5), 0 6px 12px rgba(30,150,80,.35);}
  40%{box-shadow:0 0 26px rgba(255,224,140,.95), 0 0 10px #fff, inset 0 0 8px rgba(255,255,255,.8);}}
.prow.celebrate{animation:winPop .55s cubic-bezier(.2,1.4,.4,1);z-index:4;}
.prow.celebrate .cell{animation:cellGlow .6s ease;}
.prow.celebrate .sumtab{animation:cellGlow .6s ease;}
@keyframes winBounce{0%{transform:translateY(0);}22%{transform:translateY(-12px);}48%{transform:translateY(5px);}72%{transform:translateY(-4px);}100%{transform:translateY(0);}}
.pyramid.winbounce{animation:winBounce .9s cubic-bezier(.2,1,.3,1) .12s;}
/* line focus / spotlight */
.board.focusing .cell{transition:opacity .15s, outline-color .15s;}
.board.focusing .cell:not(.focus-row):not(.focus-col){opacity:.4;}
.cell.focus-row{outline:2px solid rgba(124,156,255,.55);outline-offset:-2px;}
.cell.focus-col{outline:2px solid rgba(255,139,208,.5);outline-offset:-2px;}
.sumtab.focus{box-shadow:0 0 0 3px rgba(124,156,255,.55), inset 0 2px 0 rgba(255,255,255,.55);}
.colchip.focus .cc-clue{box-shadow:0 0 0 3px rgba(255,139,208,.6);}
.cell.reject{animation:reject .32s ease;border-color:var(--bad)!important;}
/* a cell that's part of an impossible line (can no longer reach its target/balance) */
.cell.bad{border-color:var(--bad)!important;
  box-shadow:0 0 0 2px rgba(255,90,114,.65), 0 0 12px rgba(255,90,114,.5)!important;}
.cell.bad::after{content:'!';position:absolute;top:2px;right:5px;font-size:11px;font-weight:900;color:var(--bad);}
/* shared middle cell of each row (the axis the two Σ halves share) */
.cell.mid::before{content:'';position:absolute;bottom:4px;left:50%;transform:translateX(-50%);
  width:40%;height:3px;border-radius:3px;background:rgba(255,210,120,.7);}
.cell.mid.given::before,.cell.mid.filled::before{background:rgba(255,255,255,.55);}
/* wrong-row flash (numbers are kept so you can fix the offending cell) */
.prow.wrong .cell.filled{background:linear-gradient(180deg,#ff7a8f,#e0455f)!important;border-color:transparent!important;color:#fff!important;}
.prow.wrong .sumtab.right{background:linear-gradient(180deg,#ff9aab,#e0455f);color:#fff;}
@keyframes reject{0%,100%{transform:translateX(0);}25%{transform:translateX(-6px);}75%{transform:translateX(6px);}}
.prow.shake{animation:shake .4s ease;}
@keyframes shake{0%,100%{transform:translateX(0);}20%{transform:translateX(-9px);}40%{transform:translateX(8px);}60%{transform:translateX(-6px);}80%{transform:translateX(4px);}}

/* column clue bar under the base: running total (top) + fixed target clue (gold tab) */
/* column bar aligns under the base cells: centered chips + a spacer matching the totals column */
.colbar-row{display:flex;align-items:flex-start;gap:var(--gap);margin-top:12px;padding-top:12px;border-top:1px dashed rgba(255,255,255,.14);}
.colbar-row .tab-spacer{flex:none;width:var(--tab-w);}
.colbar{flex:1;display:flex;gap:var(--gap);justify-content:center;}
.colchip{flex:none;width:var(--cell);display:flex;flex-direction:column;align-items:center;gap:4px;}
.colchip .cc-cur{font-weight:800;font-size:calc(var(--cell) * .30);font-variant-numeric:tabular-nums;
  color:var(--ink-dim);line-height:1;transition:color .2s;}
.colchip .cc-cur i{font-style:normal;opacity:.5;font-size:.8em;}
.colchip .cc-clue{width:100%;height:calc(var(--cell) * .64);border-radius:10px;display:grid;place-items:center;
  font-weight:900;font-size:calc(var(--cell) * .38);font-variant-numeric:tabular-nums;color:#3a2408;
  background:linear-gradient(180deg,#ffd27a,#f0a63a);
  box-shadow:inset 0 2px 0 rgba(255,255,255,.5), inset 0 -3px 6px rgba(0,0,0,.15);transition:all .2s;}
.colchip.match .cc-cur{color:var(--good);}
.colchip.match .cc-clue{background:linear-gradient(180deg,#8effb0,#3fd07a);color:#06210f;box-shadow:0 4px 12px rgba(30,150,80,.4);}
.colchip.mism .cc-cur{color:var(--bad);}
.colchip.mism .cc-clue{background:linear-gradient(180deg,#ff9aab,#e0455f);color:#fff;}


/* ---------- assist panel + next-move highlight ---------- */
.assist-panel{width:min(720px,100%);display:none;flex-direction:column;gap:3px;margin:2px 0 8px;
  padding:10px 14px;border-radius:14px;
  background:linear-gradient(180deg, rgba(124,156,255,.18), rgba(124,156,255,.08));
  border:1px solid rgba(124,156,255,.5);box-shadow:0 6px 18px rgba(60,80,180,.25);}
.assist-panel.show{display:flex;animation:fadeIn .2s ease both;}
.assist-panel .as-move{font-size:clamp(16px,4vw,18px);font-weight:800;color:#e9edff;}
.assist-panel .as-move b{color:#fff;background:linear-gradient(180deg,#8a7dff,#5a63d8);
  padding:2px 11px;border-radius:8px;margin:0 1px;box-shadow:inset 0 1px 0 rgba(255,255,255,.3);}
.assist-panel .as-why{font-size:clamp(14px,3.6vw,16px);line-height:1.45;color:#c8d0f0;}
.cell.assist-line{outline:2px dashed rgba(124,156,255,.5);outline-offset:-2px;}
.cell.assist-target{animation:assistPulse 1.15s ease-in-out infinite;z-index:2;}
@keyframes assistPulse{0%,100%{box-shadow:0 0 0 3px rgba(124,156,255,.5), 0 0 8px rgba(124,156,255,.4);}
  50%{box-shadow:0 0 0 5px rgba(124,156,255,.9), 0 0 20px rgba(124,156,255,.8);}}
.btn-assist{background:linear-gradient(160deg,#8ea6ff,#5a72e8);color:#fff;border:none;box-shadow:0 8px 18px rgba(90,114,232,.35);}
.btn-assist.on{background:linear-gradient(160deg,#7cf0c0,#22b48a);color:#03271c;box-shadow:0 8px 18px rgba(34,180,138,.45);}

/* ---------- controls (mobile-first: actions row + full-width numpad) ---------- */
.controls{width:min(520px,100%);display:flex;flex-direction:column;gap:8px;margin-top:8px;}
.actions{display:flex;gap:8px;}
.actions .btn{flex:1;min-height:48px;padding:12px 10px;font-size:15px;}
.numpad{width:100%;display:grid;grid-template-columns:repeat(5,1fr);gap:8px;}
.np{min-height:clamp(48px,13vw,60px);border-radius:14px;font-size:clamp(22px,6vw,26px);font-weight:900;color:#fff;cursor:pointer;
  display:grid;place-items:center;
  background:linear-gradient(180deg, rgba(255,255,255,.11), rgba(255,255,255,.03));border:1px solid var(--line);
  box-shadow:inset 0 1px 0 rgba(255,255,255,.25), 0 6px 12px rgba(0,0,0,.25);transition:transform .08s ease, background .15s, opacity .2s;}
.np:hover{background:rgba(255,255,255,.15);}
.np:active{transform:translateY(2px) scale(.95);background:var(--accent);}
.np.flash{animation:npFlash .25s ease;}
@keyframes npFlash{0%{background:var(--accent);}100%{}}
.np.disabled{opacity:.2;cursor:not-allowed;pointer-events:none;}
.np.glow{animation:npGlow 1.15s ease-in-out infinite;}
@keyframes npGlow{0%,100%{box-shadow:inset 0 1px 0 rgba(255,255,255,.25), 0 0 0 rgba(124,156,255,0);}
  50%{box-shadow:0 0 18px 3px rgba(124,156,255,.75);}}
.btn-hint{background:linear-gradient(160deg,#ffcf5c,#f0a63a);color:#3a2600;border:none;box-shadow:0 8px 18px rgba(240,166,58,.4);}
.btn-hint:disabled{opacity:.4;cursor:not-allowed;transform:none;}
.btn-erase{padding:11px;}

/* ---------- learn button + tutorial ---------- */
.btn-learn{background:linear-gradient(160deg,#ffd27a,#ff8bd0);color:#3a1230;border:none;
  box-shadow:0 10px 24px rgba(255,140,200,.4), inset 0 1px 0 rgba(255,255,255,.5);font-weight:900;letter-spacing:.08em;}
.tut-top{width:min(720px,100%);display:flex;align-items:center;gap:10px;margin-bottom:8px;}
.tut-progress{flex:1;display:flex;gap:6px;justify-content:center;}
.tut-progress i{width:26px;height:6px;border-radius:6px;background:rgba(255,255,255,.15);transition:background .3s;}
.tut-progress i.on{background:linear-gradient(90deg,#ffd27a,#ff8bd0);}
.tut-progress i.done{background:var(--good);}
.tut-step-label{font-size:11px;letter-spacing:.14em;color:var(--ink-dim);min-width:64px;text-align:right;}
/* board gets priority; the coach is a compact bar that can't dominate */
#screen-tutorial .board-scroll{flex:1 1 auto;min-height:38vh;}
.coach{flex:none;width:min(600px,100%);display:flex;gap:12px;align-items:center;margin:8px auto 6px;padding:12px 16px;border-radius:16px;
  max-height:30vh;overflow-y:auto;
  background:linear-gradient(180deg, rgba(255,210,122,.14), rgba(255,139,208,.09));
  border:1px solid rgba(255,180,120,.4);box-shadow:0 8px 20px rgba(120,60,90,.22);}
.coach.pop{animation:coachIn .3s cubic-bezier(.2,1.3,.4,1) both;}
@keyframes coachIn{from{opacity:0;transform:translateY(8px) scale(.97);}to{opacity:1;transform:none;}}
.coach-emoji{font-size:clamp(30px,7vw,38px);flex:none;filter:drop-shadow(0 3px 5px rgba(0,0,0,.35));animation:bob 2.4s ease-in-out infinite;}
@keyframes bob{0%,100%{transform:translateY(0) rotate(-3deg);}50%{transform:translateY(-4px) rotate(3deg);}}
.coach-text{font-size:clamp(14px,3.7vw,17px);line-height:1.4;color:#fff5ea;font-weight:500;}
.coach-text b{color:#ffe0a8;font-weight:800;}
.coach-text .k{background:linear-gradient(180deg,#8a7dff,#5a63d8);color:#fff;padding:2px 10px;border-radius:8px;font-weight:800;white-space:nowrap;}
.coach-text .c-lft{color:#ffd98a;}
.coach-text .c-rgt{color:#ff9ed6;}
.cell.tut-hi{animation:assistPulse 1.1s ease-in-out infinite;z-index:2;cursor:pointer;}
.colchip.tut-hi .cc-clue{box-shadow:0 0 0 3px rgba(255,139,208,.8);animation:assistPulse 1.1s ease-in-out infinite;}
#tut-next{width:100%;min-height:52px;font-size:17px;}
/* animated "these tiles are being added up" sweep (tutorial + assist) */
@keyframes sumHi{0%,100%{box-shadow:inset 0 2px 6px rgba(0,0,0,.25);}
  50%{box-shadow:0 0 0 3px rgba(255,214,130,.9), 0 0 16px rgba(255,184,90,.65);transform:translateY(-3px) scale(1.05);}}
.cell.sum-hi{animation:sumHi 1.5s ease-in-out infinite;animation-delay:var(--d,0s);z-index:3;}
@keyframes sumHiR{0%,100%{box-shadow:inset 0 2px 6px rgba(0,0,0,.25);}
  50%{box-shadow:0 0 0 3px rgba(255,139,208,.95), 0 0 16px rgba(255,120,190,.65);transform:translateY(-3px) scale(1.05);}}
.cell.sum-hi-r{animation:sumHiR 1.5s ease-in-out infinite;animation-delay:var(--d,0s);z-index:3;}
.cell.mid-share{outline:2px dashed rgba(255,255,255,.55);outline-offset:-3px;}
@keyframes totalGlow{0%,100%{filter:brightness(1);box-shadow:inset 0 2px 0 rgba(255,255,255,.5);}
  50%{filter:brightness(1.22);box-shadow:0 0 0 3px rgba(255,214,130,.9), 0 0 18px rgba(255,184,90,.7);}}
.sumtab.total-hi{animation:totalGlow 1.5s ease-in-out infinite;animation-delay:.5s;}
.colchip.total-hi .cc-clue{animation:totalGlow 1.5s ease-in-out infinite;animation-delay:.5s;}
.cell.tut-sel{outline:3px solid var(--accent);outline-offset:-2px;box-shadow:0 0 0 4px rgba(124,156,255,.35);}

/* ---------- completion banding box ---------- */
.band-box{position:fixed;z-index:8;pointer-events:none;border:3px solid var(--band,#4ade80);border-radius:15px;
  box-shadow:0 0 20px var(--band,#4ade80), inset 0 0 14px color-mix(in srgb, var(--band,#4ade80) 40%, transparent);
  animation:bandPop .85s cubic-bezier(.2,1.1,.4,1) forwards;}
@keyframes bandPop{0%{opacity:0;transform:scale(1.12);}18%{opacity:1;transform:scale(1);}70%{opacity:1;}100%{opacity:0;transform:scale(1.02);}}

/* ---------- toast ---------- */
.toast{position:fixed;left:50%;top:24%;transform:translate(-50%,-50%) scale(.6);z-index:20;pointer-events:none;opacity:0;
  font-size:clamp(30px,8vw,54px);font-weight:900;letter-spacing:.06em;color:#fff;text-shadow:0 6px 24px rgba(0,0,0,.5);
  text-align:center;white-space:nowrap;}
.toast.show{animation:toastPop 1.1s cubic-bezier(.2,1.4,.4,1) forwards;}
@keyframes toastPop{0%{opacity:0;transform:translate(-50%,-50%) scale(.5) rotate(-6deg);}
  18%{opacity:1;transform:translate(-50%,-50%) scale(1.05) rotate(-2deg);}
  70%{opacity:1;transform:translate(-50%,-60%) scale(1) rotate(0);}
  100%{opacity:0;transform:translate(-50%,-90%) scale(.95);}}
/* milestone banner: gold-gradient, wraps, lingers longer */
.toast.milestone{font-size:clamp(18px,5.5vw,30px);white-space:normal;max-width:92vw;line-height:1.2;
  background:linear-gradient(90deg,#ffd27a,#ff8bd0,#67e8f9);-webkit-background-clip:text;background-clip:text;
  color:transparent;filter:drop-shadow(0 4px 16px rgba(0,0,0,.55));}
.toast.milestone.show{animation:toastPop 2.4s cubic-bezier(.2,1.4,.4,1) forwards;}

/* ---------- overlay ---------- */
.overlay{position:fixed;inset:0;z-index:30;display:none;align-items:center;justify-content:center;padding:20px;
  background:rgba(6,7,18,.72);backdrop-filter:blur(6px);}
.overlay.is-active{display:flex;animation:fadeIn .3s ease both;}
.overlay-card{width:min(440px,94vw);max-height:90vh;overflow:auto;
  background:linear-gradient(180deg, var(--bg2), var(--bg1));border:1px solid var(--line);border-radius:24px;
  padding:28px 26px;box-shadow:var(--shadow);text-align:center;animation:cardPop .4s cubic-bezier(.2,1.3,.4,1) both;}
@keyframes cardPop{from{opacity:0;transform:scale(.85) translateY(20px);}to{opacity:1;transform:none;}}
.overlay-card h1{font-size:30px;margin:0 0 6px;letter-spacing:.06em;}
.overlay-card h2{font-size:22px;margin:0 0 14px;letter-spacing:.08em;}
.ov-praise{font-size:clamp(26px,7vw,40px);font-weight:900;letter-spacing:.05em;margin:0 0 6px;
  background:linear-gradient(90deg,#ffd27a,#ff8bd0,#7c9cff);-webkit-background-clip:text;background-clip:text;color:transparent;}
.ov-stars{font-size:38px;letter-spacing:8px;margin:2px 0 8px;line-height:1;}
.ov-stars .on{color:#ffd27a;filter:drop-shadow(0 2px 6px rgba(255,190,80,.5));animation:starPop .5s cubic-bezier(.2,1.4,.4,1) both;}
.ov-stars .on:nth-child(2){animation-delay:.12s;}
.ov-stars .on:nth-child(3){animation-delay:.24s;}
.ov-stars .off{color:rgba(255,255,255,.16);}
@keyframes starPop{from{opacity:0;transform:scale(.2) rotate(-30deg);}to{opacity:1;transform:none;}}
.ov-stats{display:flex;flex-direction:column;gap:8px;margin:16px 0 20px;text-align:left;}
.ov-stat{display:flex;justify-content:space-between;padding:9px 14px;border-radius:12px;background:var(--card);border:1px solid var(--line);}
.ov-stat b{color:var(--warn);font-variant-numeric:tabular-nums;}
.ov-stat.big{font-size:18px;}
.overlay-card .btn{width:100%;margin-top:8px;}

/* ---------- ⚡ BONUS ROUND ---------- */
.overlay-card.bonus-card{position:relative;overflow:hidden;border:none;
  background:linear-gradient(160deg,#2a1e4d,#3a2140);
  box-shadow:0 0 60px rgba(255,180,80,.35), 0 18px 40px rgba(0,0,0,.55);}
.overlay-card.bonus-card::before{content:'';position:absolute;inset:0;padding:2px;border-radius:24px;pointer-events:none;
  background:linear-gradient(90deg,#ffd27a,#ff8bd0,#67e8f9,#ffd27a);background-size:300% 100%;
  -webkit-mask:linear-gradient(#000 0 0) content-box,linear-gradient(#000 0 0);-webkit-mask-composite:xor;
  mask:linear-gradient(#000 0 0) content-box,linear-gradient(#000 0 0);mask-composite:exclude;
  animation:bonusBorder 3s linear infinite;}
@keyframes bonusBorder{to{background-position:300% 0;}}
.bonus-bolts{font-size:44px;display:flex;justify-content:center;gap:14px;margin-bottom:2px;}
.bonus-bolts span{display:inline-block;filter:drop-shadow(0 0 14px #ffd27a);animation:boltZap .9s ease-in-out infinite;}
.bonus-bolts span:nth-child(2){animation-delay:.15s;}
.bonus-bolts span:nth-child(3){animation-delay:.3s;}
@keyframes boltZap{0%,100%{transform:translateY(0) scale(1) rotate(-6deg);}50%{transform:translateY(-6px) scale(1.28) rotate(6deg);}}
.bonus-title{font-size:clamp(42px,12vw,72px);font-weight:900;letter-spacing:.03em;line-height:.9;margin:2px 0 12px;
  background:linear-gradient(90deg,#ffd27a,#ff8bd0,#67e8f9);-webkit-background-clip:text;background-clip:text;color:transparent;
  filter:drop-shadow(0 4px 18px rgba(255,150,80,.5));animation:bonusZoom .7s cubic-bezier(.2,1.5,.4,1) both;}
@keyframes bonusZoom{0%{opacity:0;transform:scale(.3) rotate(-8deg);}60%{transform:scale(1.12);}100%{opacity:1;transform:none;}}
.bonus-sub{color:var(--ink-dim);font-size:15px;line-height:1.5;margin:7px 0;}
.bonus-sub b{color:#ffd27a;}
.bonus-rule{background:rgba(163,230,53,.12);border:1px solid rgba(163,230,53,.4);border-radius:14px;
  padding:11px 14px;margin:8px 0;font-size:14px;line-height:1.5;color:var(--ink);text-align:left;}
.bonus-rule b{color:#c6f866;}
.br-tag{display:inline-block;background:#a3e635;color:#1a2408;font-weight:900;font-size:11px;
  letter-spacing:.04em;padding:3px 9px;border-radius:999px;margin-right:6px;}
.bonus-timer{font-size:36px;font-weight:900;color:#ff8bd0;margin:14px 0 6px;font-variant-numeric:tabular-nums;
  animation:bonusPulse 1s ease-in-out infinite;}
@keyframes bonusPulse{0%,100%{transform:scale(1);}50%{transform:scale(1.09);}}
.bonus-praise{background:linear-gradient(90deg,#ffd27a,#ff8bd0,#67e8f9)!important;
  -webkit-background-clip:text;background-clip:text;color:transparent;}
.rule-pill.bonus-pill{background:linear-gradient(90deg,#ffd27a,#ff8bd0);color:#2a1030;animation:bonusPulse 1.2s ease-in-out infinite;}
body.bonus-round #screen-game{box-shadow:inset 0 0 120px rgba(255,180,90,.10);}

/* ---------- how to ---------- */
.howto-card{text-align:left;}
.howto-list{margin:0 0 16px;padding-left:20px;line-height:1.55;color:var(--ink-dim);font-size:14px;}
.howto-list li{margin-bottom:9px;}
.howto-list b{color:var(--ink);}
.howto-demo{display:flex;flex-direction:column;align-items:center;gap:5px;margin:4px 0 16px;--cell:34px;}
.howto-demo .prow{gap:5px;}

/* ---------- responsive ---------- */
@media (max-width:560px){
  :root{--cell:46px;--gap:6px;}
  .numpad{gap:6px;}
  .hud{gap:6px;padding:7px 8px;margin-bottom:6px;}
  .hud-label{letter-spacing:.06em;}
  .hud-val{font-size:17px;}
  .hud-btn{width:38px;height:38px;}
  /* keep the banner tight but the variation label big and legible */
  .rule-banner{gap:6px;margin-bottom:5px;}
  .rule-pill{padding:6px 16px;font-size:16px;}
  .game-logo{gap:4px;margin:1px 0 5px;}
  .game-logo .logo-shingle{width:22px;height:26px;font-size:14px;border-radius:6px;}
  .assist-panel{margin:3px 0 5px;padding:8px 12px;}
  .controls{gap:6px;margin-top:6px;}
  .actions .btn{min-height:44px;}
}
@media (max-width:380px){
  :root{--cell:42px;}
  .hud-label{font-size:9px;}
  .hud-val{font-size:15px;}
  .actions .btn{font-size:13px;padding:11px 6px;}
}
@media (min-height:780px){:root{--cell:54px;}}
@media (min-height:900px){:root{--cell:58px;}}
/* landscape phones: reclaim vertical space, keep everything on one screen */
@media (orientation:landscape) and (max-height:520px){
  :root{--cell:34px;--gap:4px;}
  .game-logo{display:none;}
  .rule-banner{margin-bottom:4px;}
  .hud{margin-bottom:6px;padding:6px 10px;}
  .controls{width:min(680px,100%);}
  .np{min-height:40px;font-size:20px;}
  .actions .btn{min-height:40px;padding:8px;}
  .assist-panel{margin:2px 0 4px;padding:6px 12px;}
}