:root{
  --bg:#f6f8fb;
  --card:#ffffff;
  --ink:#111827;
  --muted:#6b7280;
  --line:#e5e7eb;
  --good:#16a34a;
  --bad:#dc2626;
  --shadow: 0 10px 30px rgba(0,0,0,.10);
}

*{ box-sizing:border-box; }
html,body{ height:100%; }
body{
  margin:0;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  background:var(--bg);
  color:var(--ink);
}

.header{
  padding:16px 16px 10px;
  display:flex;
  gap:16px;
  align-items:flex-start;
  justify-content:space-between;
  flex-wrap:wrap;
  border-bottom:1px solid var(--line);
  background:rgba(255,255,255,.7);
  backdrop-filter: blur(6px);
  position:sticky;
  top:0;
  z-index:10;
}

.title h1{ margin:0; font-size:18px; }
.title p{ margin:4px 0 0; color:var(--muted); font-size:13px; max-width: 60ch; }

.hud{ display:flex; gap:10px; align-items:center; flex-wrap:wrap; }
.chip{
  display:flex; gap:6px; align-items:center;
  padding:8px 10px; border:1px solid var(--line);
  border-radius:12px; background:var(--card);
  box-shadow: 0 4px 14px rgba(0,0,0,.05);
  font-size:13px; color:var(--muted);
}
.chip strong{ color:var(--ink); }

.btn{
  border:1px solid var(--line);
  background:var(--card);
  padding:9px 12px;
  border-radius:12px;
  cursor:pointer;
  box-shadow: 0 4px 14px rgba(0,0,0,.05);
}
.btn:active{ transform: translateY(1px); }

.main{
  padding:16px;
  display:grid;
  grid-template-columns: 1fr;
  gap:16px;
  max-width: 1100px;
  margin:0 auto;
}

@media (min-width: 900px){
  .main{ grid-template-columns: 520px 1fr; align-items:start; }
}

.cardArea{
  background:var(--card);
  border:1px solid var(--line);
  border-radius:18px;
  padding:14px;
  box-shadow: var(--shadow);
}

.cardFrame{
  width:100%;
  display:flex;
  justify-content:center;
  align-items:center;
  padding:10px 0;
  position:relative;
  min-height: 360px;
}

.dropTarget{
  position:relative;
  display:inline-flex;
  align-items:center;
  justify-content:center;
  padding:16px;
  border:2px dashed #cbd5e1;
  border-radius:18px;
  transition: border-color .08s ease, box-shadow .08s ease, transform .08s ease;
}

.dropTarget.over{
  border-color:#60a5fa;
  box-shadow: 0 10px 25px rgba(37,99,235,.12);
  transform: translateY(-2px);
}

.hint{
  position:absolute;
  bottom:10px;
  right:12px;
  font-size:12px;
  color:var(--muted);
  background:rgba(255,255,255,.85);
  padding:4px 8px;
  border-radius:999px;
  border:1px solid var(--line);
  pointer-events:none;
}

.card{
  width:min(360px, 90vw);
  height:auto;
  border-radius:14px;
  box-shadow: 0 10px 25px rgba(0,0,0,.12);
  user-select:none;
  -webkit-user-drag:none;
}

.feedback{
  min-height: 24px;
  margin-top:8px;
  font-weight:800;
}
.feedback.good{ color:var(--good); }
.feedback.bad{ color:var(--bad); }

.ops{
  display:flex;
  align-items:stretch;
}
.opCard{
  width:100%;
  background:var(--card);
  border:1px solid var(--line);
  border-radius:18px;
  padding:14px;
  box-shadow: var(--shadow);
}
.opTitle{
  font-size:13px;
  color:var(--muted);
  text-transform:uppercase;
  letter-spacing:.06em;
  margin-bottom:10px;
}
.opGrid{
  display:grid;
  grid-template-columns: repeat(2, 1fr);
  gap:12px;
}
@media (min-width: 900px){
  .opGrid{ grid-template-columns: repeat(4, 1fr); }
}

.opTile{
  border:2px solid var(--line);
  background: #fff;
  border-radius:18px;
  font-size:56px;
  font-weight:900;
  line-height:1;
  padding:18px 0;
  cursor:grab;
  box-shadow: 0 8px 20px rgba(0,0,0,.06);
}
.opTile:active{ cursor:grabbing; transform: translateY(1px); }
.opTile:focus{ outline:3px solid rgba(96,165,250,.45); outline-offset:2px; }

.footer{
  padding:10px 16px 20px;
  color:var(--muted);
  text-align:center;
}

.small{ font-size:12px; }
.muted{ color:var(--muted); margin:10px 0 0; }

.dialog{
  border:1px solid var(--line);
  border-radius:18px;
  padding:16px 16px 12px;
  box-shadow: var(--shadow);
  max-width: 420px;
}
.dialogActions{ display:flex; justify-content:flex-end; margin-top:10px; }