/* style.css — Sticker Quest */
:root{
  --bg1:#0f0f1a; --bg2:#1a1a2e; --bg3:#16213e;
  --card:#fdf9ef; --card-ink:#221405; --ink:#e8e0d0;
  --accent:#e94560; --accent2:#533483; --good:#22c55e; --bad:#ef4444;
  --shadow:0 12px 40px rgba(0,0,0,.55);
  --radius:20px;
  color-scheme: dark;
}
@media (prefers-color-scheme: light){
  :root{
    --bg1:#f5f0e6; --bg2:#ede5d5; --bg3:#e0d5c0;
    --card:#fffef8; --card-ink:#221405; --ink:#3a2a1a;
    --shadow:0 12px 40px rgba(0,0,0,.12);
    color-scheme: light;
  }
}
html[data-theme="dark"]{
  --bg1:#0f0f1a; --bg2:#1a1a2e; --bg3:#16213e;
  --card:#fdf9ef; --card-ink:#221405; --ink:#e8e0d0;
  --shadow:0 12px 40px rgba(0,0,0,.55);
  color-scheme: dark;
}
html[data-theme="light"]{
  --bg1:#f5f0e6; --bg2:#ede5d5; --bg3:#e0d5c0;
  --card:#fffef8; --card-ink:#221405; --ink:#3a2a1a;
  --shadow:0 12px 40px rgba(0,0,0,.12);
  color-scheme: light;
}

*{box-sizing:border-box;}
html,body{margin:0;padding:0;height:100%;}
body{
  font-family:-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,Helvetica,Arial,sans-serif;
  color:var(--ink);
  background:linear-gradient(160deg,var(--bg1) 0%,var(--bg2) 40%,var(--bg3) 100%);
  overflow:hidden;
  touch-action:manipulation;
  -webkit-tap-highlight-color:transparent;
}
#app{
  height:100%;
  display:flex;flex-direction:column;
  max-width:680px;margin:0 auto;
  padding:env(safe-area-inset-top) 16px env(safe-area-inset-bottom);
}

/* Topbar */
.topbar{
  display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;
  padding:12px 4px 8px;gap:10px;
}
.brand{display:flex;flex-direction:column;}
.brand h1{
  font-size:24px;font-weight:800;margin:0;letter-spacing:.5px;
  background:linear-gradient(135deg,#e94560,#ffb02e);
  -webkit-background-clip:text;-webkit-text-fill-color:transparent;
  background-clip:text;
}
.brand-sub{
  font-size:10px;font-weight:600;text-transform:uppercase;letter-spacing:.12em;
  opacity:.5;margin-top:1px;
}
.topbar-right{display:flex;align-items:center;gap:8px;flex-wrap:wrap;justify-content:flex-end;}
.stats{display:flex;gap:8px;}
.stat{
  background:rgba(255,255,255,.06);
  border:1px solid rgba(255,255,255,.1);
  border-radius:14px;padding:6px 12px;text-align:center;min-width:56px;
  backdrop-filter:blur(4px);
}
.stat-num{display:block;font-weight:800;font-size:19px;line-height:1.1;}
.stat-lbl{display:block;font-size:9px;text-transform:uppercase;letter-spacing:.08em;opacity:.55;margin-top:2px;}
.streak-stat{
  background:rgba(255,215,0,.1);border-color:rgba(255,215,0,.25);
}
.streak-stat .stat-num{color:#ffd166;}

/* Focus mode button */
.focus-btn{
  border:1px solid rgba(255,255,255,.18);background:rgba(255,255,255,.07);
  color:var(--ink);border-radius:999px;padding:9px 16px;
  font-weight:800;font-size:12px;letter-spacing:.06em;text-transform:uppercase;
  cursor:pointer;transition:all .2s;user-select:none;
}
.focus-btn:hover{background:rgba(255,255,255,.15);}
.focus-btn:active{transform:scale(.95);}
.focus-btn.on{
  background:linear-gradient(135deg,#e94560,#c23152);
  border-color:rgba(255,255,255,.35);color:#fff;
  box-shadow:0 4px 14px rgba(233,69,96,.35);
}

/* Focus mode layout */
body.focus-mode .collection{display:none;}
body.focus-mode .brand-sub{display:none;}
body.focus-mode .card-scene{max-width:min(400px,90vw);}
body.focus-mode .card-eq{font-size:clamp(58px,17vw,96px);}
body.focus-mode .stage{gap:20px;}

/* Ops bar */
.ops-bar{display:flex;gap:10px;padding:10px 2px 6px;}
.op-btn{
  flex:1;display:flex;flex-direction:column;align-items:center;gap:2px;
  border:1px solid rgba(255,255,255,.15);background:rgba(255,255,255,.06);
  color:var(--ink);border-radius:14px;padding:8px 4px;cursor:pointer;
  font-weight:700;transition:all .2s cubic-bezier(.34,1.56,.64,1);
  user-select:none;
}
.op-btn.active{
  background:rgba(255,255,255,.92);color:#1a1a2e;border-color:rgba(255,255,255,.9);
  box-shadow:0 4px 16px rgba(0,0,0,.25);
}
.op-btn:not(.active):hover{background:rgba(255,255,255,.15);}
.op-btn:active{transform:scale(.94);}
.op-sym{font-size:22px;line-height:1;}
.op-name{font-size:10px;text-transform:uppercase;letter-spacing:.06em;opacity:.7;}
.op-btn.active .op-name{opacity:1;}

/* Stage */
.stage{flex:1;overflow-y:auto;overflow-x:hidden;padding:8px 2px 20px;display:flex;flex-direction:column;gap:16px;}
.stage::-webkit-scrollbar{width:5px;}
.stage::-webkit-scrollbar-thumb{background:rgba(255,255,255,.15);border-radius:3px;}

/* Streak track */
.streak-track{padding:0 2px;}
.streak-label{
  font-size:13px;font-weight:700;text-align:center;margin-bottom:8px;
  text-shadow:0 1px 3px rgba(0,0,0,.3);
  transition:opacity .3s;
}
.streak-bar{
  position:relative;height:18px;border-radius:999px;
  background:rgba(0,0,0,.25);overflow:hidden;
  border:1px solid rgba(255,255,255,.12);
}
.streak-fill{
  height:100%;width:0;border-radius:999px;
  background:linear-gradient(90deg,#ffd166,#e94560,#533483);
  transition:width .5s cubic-bezier(.34,1.56,.64,1);
  box-shadow:0 0 12px rgba(233,69,96,.4);
}

/* Card scene */
.card-wrap{display:flex;justify-content:center;perspective:900px;}
.card-scene{
  width:100%;max-width:320px;aspect-ratio:2.5/3.4;
  transition:max-width .3s;
}
@supports not (aspect-ratio: 2.5/3.4){
  .card-scene{height:400px;max-height:62vh;}
}
.flashcard{
  position:relative;width:100%;height:100%;
  transition:transform .34s cubic-bezier(.34,1.35,.64,1);
  will-change:transform;
}
.flashcard.flip-away{
  transform:rotateY(90deg) scale(.94);
  transition-duration:.18s;
  transition-timing-function:cubic-bezier(.55,.06,.68,.19);
}
.flashcard.shake{animation:shake .45s;}
.card-face{
  position:absolute;inset:0;
  border-radius:var(--radius);
  box-shadow:var(--shadow);
  border:3px solid rgba(255,255,255,.35);
  display:flex;align-items:center;justify-content:center;
  overflow:hidden;
}
.card-back{
  display:none;
  background:linear-gradient(145deg,#1a3a5c,#2a5a8c);
  background-image:
    repeating-linear-gradient(45deg,transparent,transparent 12px,rgba(255,255,255,.04) 12px,rgba(255,255,255,.04) 24px),
    radial-gradient(ellipse at 30% 20%,rgba(255,255,255,.08),transparent 60%);
}
.card-front{
  background:var(--card);color:var(--card-ink);
  flex-direction:column;gap:6px;
  padding:16px;
  border-color:rgba(0,0,0,.15);
  transition:border-color .25s, box-shadow .25s;
}
.flashcard.card-correct .card-front{
  border-color:var(--good);
  box-shadow:0 0 30px rgba(34,197,94,.3),var(--shadow);
}
.flashcard.card-wrong .card-front{
  border-color:var(--bad);
  box-shadow:0 0 20px rgba(239,68,68,.25),var(--shadow);
}
.card-border{
  position:absolute;inset:6px;border:2px solid rgba(0,0,0,.08);
  border-radius:calc(var(--radius) - 4px);pointer-events:none;
}
/* Big readable equation */
.card-eq{
  display:flex;align-items:center;justify-content:center;gap:.16em;
  flex:1;width:100%;
  font-weight:800;color:var(--card-ink);
  font-size:clamp(48px,15vw,78px);
  line-height:1;letter-spacing:.01em;
  font-variant-numeric:tabular-nums;
  text-shadow:0 2px 0 rgba(0,0,0,.06);
}
.card-eq .eq-num{display:inline-block;}
.card-eq .op-symbol{color:var(--accent);transform:translateY(-.03em);}

/* Answer area */
.answer-area{text-align:center;}
.answer-display{
  font-weight:800;font-size:40px;
  min-height:56px;color:var(--accent);
  background:rgba(255,255,255,.06);border-radius:16px;
  padding:8px 14px;margin-bottom:10px;
  border:2px dashed rgba(255,255,255,.15);
  transition:border-color .3s, background .3s;
  font-variant-numeric:tabular-nums;
}
.answer-display .cursor{animation:blink 1s steps(2) infinite;}
.feedback{min-height:40px;font-weight:700;display:flex;flex-direction:column;align-items:center;gap:2px;}
.fb-big{display:block;font-size:20px;letter-spacing:.02em;}
.fb-correct .fb-big{color:var(--good);}
.fb-wrong .fb-big{color:var(--bad);}
.fb-ans{display:block;font-size:15px;color:var(--ink);margin-top:2px;}
.fb-ans b{color:var(--accent);font-size:24px;font-weight:800;}

/* Numpad */
.numpad{
  display:grid;grid-template-columns:repeat(4,1fr);gap:10px;
  max-width:400px;margin:0 auto;width:100%;
}
.key{
  font-weight:800;font-size:26px;
  border:none;border-radius:16px;padding:16px 0;cursor:pointer;
  background:rgba(255,255,255,.92);color:#1a1a2e;
  box-shadow:0 5px 0 rgba(0,0,0,.18),0 8px 16px rgba(0,0,0,.12);
  transition:transform .08s cubic-bezier(.34,1.56,.64,1), box-shadow .08s;
  user-select:none;-webkit-user-select:none;
  position:relative;overflow:hidden;
}
.key::after{
  content:'';position:absolute;inset:0;
  background:linear-gradient(180deg,rgba(255,255,255,.3) 0%,transparent 50%);
  border-radius:inherit;pointer-events:none;
}
.key:active{
  transform:translateY(3px);
  box-shadow:0 2px 0 rgba(0,0,0,.18),0 3px 8px rgba(0,0,0,.1);
}
.key-clear{background:#ffe8e8;color:#c0392b;}
.key-go{
  background:linear-gradient(135deg,#e94560,#c23152);color:#fff;
  box-shadow:0 5px 0 #8b1a30,0 8px 16px rgba(233,69,96,.3);
  font-size:22px;letter-spacing:.08em;
}
.key-go:active{box-shadow:0 2px 0 #8b1a30,0 3px 8px rgba(233,69,96,.2);}

/* Setup screen — choose your problem types */
.setup{
  position:fixed;inset:0;z-index:70;
  background:linear-gradient(160deg,var(--bg1) 0%,var(--bg2) 45%,var(--bg3) 100%);
  display:flex;align-items:center;justify-content:center;
  padding:20px;overflow-y:auto;
  animation:fadeIn .35s;
}
.setup[hidden]{display:none;}
.setup-card{
  width:100%;max-width:420px;text-align:center;
  background:rgba(255,255,255,.05);
  border:1px solid rgba(255,255,255,.12);
  border-radius:28px;padding:28px 22px 26px;
  box-shadow:var(--shadow);
  backdrop-filter:blur(8px);
  animation:revealUp .5s cubic-bezier(.34,1.56,.64,1);
}
.setup-badge{
  font-size:64px;line-height:1;margin-bottom:6px;
  display:flex;justify-content:center;align-items:center;
  animation:lootBob 2.2s ease-in-out infinite;
}
.setup-badge-img{
  width:96px;height:96px;object-fit:contain;display:block;
  filter:drop-shadow(0 8px 18px rgba(0,0,0,.45));
}
.setup-title{
  font-size:32px;font-weight:800;margin:4px 0 0;letter-spacing:.5px;
  background:linear-gradient(135deg,#e94560,#ffb02e);
  -webkit-background-clip:text;-webkit-text-fill-color:transparent;
  background-clip:text;
}
.setup-sub{
  font-size:14px;font-weight:600;opacity:.75;line-height:1.5;margin:8px 0 18px;
}
.setup-pick{
  font-size:12px;font-weight:800;text-transform:uppercase;letter-spacing:.14em;
  opacity:.6;margin-bottom:10px;
}
.op-choices{display:flex;gap:10px;margin-bottom:20px;}
.op-choice{
  flex:1;display:flex;flex-direction:column;align-items:center;gap:4px;
  border:2px solid rgba(255,255,255,.15);background:rgba(255,255,255,.06);
  color:var(--ink);border-radius:18px;padding:16px 6px 12px;cursor:pointer;
  font-weight:700;transition:all .18s cubic-bezier(.34,1.56,.64,1);
  user-select:none;
}
.op-choice:hover{background:rgba(255,255,255,.12);transform:translateY(-2px);}
.op-choice:active{transform:scale(.95);}
.op-choice.selected{
  background:rgba(255,255,255,.95);color:#1a1a2e;
  border-color:#ffd166;
  box-shadow:0 0 0 3px rgba(255,209,102,.35),0 8px 20px rgba(0,0,0,.3);
  transform:translateY(-3px);
}
.oc-sym{
  font-size:34px;line-height:1;font-weight:800;
}
.op-choice[data-op="add"] .oc-sym{color:#22c55e;}
.op-choice[data-op="sub"] .oc-sym{color:#3aa7ff;}
.op-choice[data-op="mul"] .oc-sym{color:#e94560;}
.op-choice.selected .oc-sym{color:inherit;}
.oc-name{font-size:11px;text-transform:uppercase;letter-spacing:.05em;opacity:.85;}
.start-btn{
  width:100%;font-weight:800;font-size:20px;letter-spacing:.04em;
  border:none;border-radius:999px;padding:16px 0;cursor:pointer;
  background:linear-gradient(135deg,#e94560,#533483);color:#fff;
  box-shadow:0 6px 0 #3a2060,0 10px 22px rgba(0,0,0,.35);
  transition:transform .1s, box-shadow .1s, filter .2s;
}
.start-btn:active{transform:translateY(3px);box-shadow:0 3px 0 #3a2060,0 5px 12px rgba(0,0,0,.3);}
.start-btn:disabled{
  background:rgba(255,255,255,.12);color:rgba(255,255,255,.45);
  box-shadow:none;cursor:not-allowed;filter:none;
}

/* Collection — sticker album */
.collection{margin-top:4px;}
.coll-head{display:flex;align-items:baseline;justify-content:space-between;padding:0 4px;margin-bottom:10px;}
.coll-head h2{font-size:19px;margin:0;font-weight:800;letter-spacing:.02em;}
.coll-count{
  font-size:11px;font-weight:700;opacity:.7;
  background:rgba(0,0,0,.15);padding:4px 12px;border-radius:999px;
}
.coll-grid{
  display:grid;grid-template-columns:repeat(auto-fill,minmax(96px,1fr));gap:10px;
  padding:6px;max-height:240px;overflow-y:auto;
}
.coll-grid::-webkit-scrollbar{width:5px;}
.coll-grid::-webkit-scrollbar-thumb{background:rgba(255,255,255,.15);border-radius:3px;}
.sticker-card{
  background:rgba(255,255,255,.92);border-radius:16px;padding:12px 6px 8px;text-align:center;
  box-shadow:0 4px 12px rgba(0,0,0,.18);position:relative;overflow:hidden;
  animation:stickerIn .45s cubic-bezier(.34,1.56,.64,1);
  transition:transform .15s;
}
.sticker-card:active{transform:scale(.95);}
.sticker-img{width:56px;height:56px;object-fit:contain;display:block;margin:0 auto;}
.sticker-emoji{font-size:44px;line-height:56px;display:block;}
.sticker-name{font-size:10px;font-weight:800;color:#2a1a0a;margin-top:5px;text-transform:uppercase;letter-spacing:.04em;}
.sticker-rarity{font-size:8px;font-weight:800;text-transform:uppercase;letter-spacing:.12em;margin-top:2px;opacity:.9;}
.sticker-card.rarity-common{border:2px solid #c8d2e0;}
.sticker-card.rarity-rare{
  border:2px solid #3aa7ff;
  box-shadow:0 0 14px rgba(58,167,255,.35),0 4px 12px rgba(0,0,0,.18);
}
.sticker-card.rarity-epic{
  border:2px solid #b14dff;
  box-shadow:0 0 16px rgba(177,77,255,.4),0 4px 12px rgba(0,0,0,.18);
}
.sticker-card.rarity-legendary{
  border:2px solid #ffb02e;
  box-shadow:0 0 20px rgba(255,176,46,.5),0 4px 12px rgba(0,0,0,.18);
  background:linear-gradient(135deg,#fffbe6,#fff5d6);
}
.sticker-mystery{
  background:rgba(255,255,255,.08);
  border:2px dashed rgba(255,255,255,.25);
  box-shadow:none;
}
.sticker-mystery .sticker-name{color:var(--ink);opacity:.55;}
.sticker-mystery .sticker-rarity{opacity:.7;}
.mystery-mark{
  width:56px;height:56px;margin:0 auto;border-radius:50%;
  display:flex;align-items:center;justify-content:center;
  font-size:30px;font-weight:800;color:rgba(255,255,255,.35);
  background:rgba(255,255,255,.07);
  border:2px dashed rgba(255,255,255,.2);
}

/* Loot modal */
.modal{
  position:fixed;inset:0;background:rgba(8,4,24,.88);backdrop-filter:blur(8px);
  display:flex;align-items:center;justify-content:center;z-index:50;
  animation:fadeIn .3s;
}
.modal[hidden]{display:none;}
.loot-stage{text-align:center;padding:20px;}
.loot-dice{
  font-size:130px;cursor:pointer;user-select:none;line-height:1;
  filter:drop-shadow(0 10px 24px rgba(0,0,0,.6));
  animation:lootBob 1.4s ease-in-out infinite;
  transition:transform .2s;
  display:inline-block;
}
.loot-dice img{width:130px;height:130px;display:block;pointer-events:none;}
.loot-dice .die-fallback{
  display:inline-flex;align-items:center;justify-content:center;
  width:120px;height:120px;border-radius:26px;
  background:linear-gradient(145deg,#e03a3a,#b01e1e);color:#fff;
  font-size:64px;font-weight:800;
  box-shadow:inset 0 -8px 16px rgba(0,0,0,.3),0 10px 24px rgba(0,0,0,.5);
}
.loot-dice:hover{transform:scale(1.06);}
.loot-dice.opened{animation:lootBurst .55s forwards;}
.loot-hint{margin-top:16px;font-size:17px;font-weight:700;color:#fff;text-shadow:0 2px 6px rgba(0,0,0,.5);transition:opacity .3s;}
.loot-reveal{animation:revealUp .55s cubic-bezier(.34,1.56,.64,1);}
.loot-reveal[hidden]{display:none;}
.loot-sticker{margin-bottom:10px;min-height:120px;display:flex;align-items:center;justify-content:center;}
.loot-sticker-img{
  width:150px;height:150px;object-fit:contain;display:block;margin:0 auto;
  filter:drop-shadow(0 10px 22px rgba(0,0,0,.55));
  animation:stickerPop .65s cubic-bezier(.34,1.56,.64,1);
}
.loot-sticker .sticker-emoji{font-size:110px;line-height:1.1;animation:stickerPop .65s cubic-bezier(.34,1.56,.64,1);}
.loot-name{font-size:32px;font-weight:800;color:#fff;text-shadow:0 2px 8px rgba(0,0,0,.5);}
.loot-rarity{font-size:15px;font-weight:800;letter-spacing:.18em;margin-top:6px;}
.loot-dup{display:block;margin-top:12px;font-size:14px;color:#ffd166;font-weight:700;}
.loot-close{
  margin-top:26px;font-weight:800;font-size:21px;
  background:linear-gradient(135deg,#e94560,#533483);color:#fff;border:none;
  padding:16px 40px;border-radius:999px;cursor:pointer;
  box-shadow:0 6px 0 #3a2060,0 10px 20px rgba(0,0,0,.3);
  transition:transform .1s;
  letter-spacing:.04em;
}
.loot-close:active{transform:translateY(3px);box-shadow:0 3px 0 #3a2060,0 5px 12px rgba(0,0,0,.3);}

/* Confetti */
.confetti-layer{position:fixed;inset:0;pointer-events:none;z-index:60;overflow:hidden;}
.confetti-piece{
  position:absolute;width:10px;height:14px;border-radius:2px;
  animation:confettiFly 1.5s ease-out forwards;
}
@keyframes confettiFly{
  0%{transform:translate(0,0) rotate(0);opacity:1;}
  100%{transform:translate(var(--dx),var(--dy)) rotate(var(--rot));opacity:0;}
}

/* Animations */
@keyframes blink{0%,50%{opacity:1;}51%,100%{opacity:0;}}
@keyframes shake{0%,100%{transform:translateX(0);}15%{transform:translateX(-10px);}30%{transform:translateX(10px);}45%{transform:translateX(-6px);}60%{transform:translateX(6px);}75%{transform:translateX(-3px);}90%{transform:translateX(3px);}}
@keyframes stickerIn{0%{transform:scale(0) rotate(-15deg);}100%{transform:scale(1) rotate(0);}}
@keyframes stickerPop{0%{transform:scale(0) rotate(-20deg);}60%{transform:scale(1.25) rotate(8deg);}100%{transform:scale(1) rotate(0);}}
@keyframes lootBob{0%,100%{transform:translateY(0) rotate(-3deg);}50%{transform:translateY(-14px) rotate(3deg);}}
@keyframes lootBurst{0%{transform:scale(1) rotate(0);}40%{transform:scale(1.4) rotate(18deg);}100%{transform:scale(0) rotate(50deg);opacity:0;}}
@keyframes revealUp{0%{transform:translateY(24px) scale(.85);opacity:0;}100%{transform:translateY(0) scale(1);opacity:1;}}
@keyframes fadeIn{from{opacity:0;}to{opacity:1;}}

/* Responsive */
@media (max-width:380px){
  .brand h1{font-size:20px;}
  .brand-sub{font-size:9px;}
  .stat{min-width:48px;padding:5px 8px;}
  .stat-num{font-size:17px;}
  .focus-btn{padding:8px 12px;font-size:11px;}
  .answer-display{font-size:34px;}
  .key{font-size:22px;padding:14px 0;border-radius:14px;}
  .loot-dice{font-size:100px;}
  .loot-dice img{width:100px;height:100px;}
  .loot-dice .die-fallback{width:96px;height:96px;font-size:52px;}
  .loot-sticker-img{width:110px;height:110px;}
  .loot-sticker .sticker-emoji{font-size:86px;}
  .loot-name{font-size:26px;}
  .card-eq{font-size:clamp(42px,14vw,62px);}
  .setup-title{font-size:26px;}
  .setup-badge{font-size:52px;}
  .setup-badge-img{width:76px;height:76px;}
  .oc-sym{font-size:28px;}
  .oc-name{font-size:9px;}
  .start-btn{font-size:17px;}
}
@media (min-width:560px){
  .numpad{gap:12px;}
  .key{font-size:28px;padding:18px 0;border-radius:18px;}
  .card-scene{max-width:340px;}
}