:root{
  /* Light theme (default) */
  --bg: #f7f8fc;
  --panel: #ffffff;
  --panel-2: #f3f4f9;
  --text: #0d1028;
  --muted: #515572;
  --brand: #4c39ff;
  --brand-2:#10b981;
  --stroke: #dfe3ef;
  --radius: 16px;
}

/* Dark mode overrides */
.dark{
  --bg: #0b0b10;
  --panel: #121219;
  --panel-2: #181826;
  --text: #e8e8f0;
  --muted: #a6a6b5;
  --brand: #7c5cff;
  --brand-2:#5ee1a6;
  --stroke: #26263a;
}

*{ box-sizing: border-box; }
html,body{ height:100%; }
body{
  margin:0;
  font-family: Inter, system-ui, -apple-system, Segoe UI, Roboto, 'Helvetica Neue', Arial, 'Noto Sans', 'Apple Color Emoji','Segoe UI Emoji','Segoe UI Symbol', sans-serif;
  color: var(--text);
  background:
    radial-gradient(900px 500px at 95% -10%, color-mix(in oklab, var(--brand) 9%, transparent), transparent 45%),
    radial-gradient(1000px 600px at 0% -10%, color-mix(in oklab, var(--brand-2) 10%, transparent), transparent 40%),
    var(--bg);
  line-height: 1.5;
}

.app-header{
  text-align:center;
  padding: 32px 16px 8px;
}
.app-title{
  font-family: "Instrument Serif", Georgia, serif;
  font-weight: 700;
  font-size: clamp(30px, 4.4vw, 50px);
  letter-spacing: .3px;
  margin: 0 0 10px;
}
.app-title span{ color: var(--brand); }
.app-tagline{
  margin: 0 auto 8px;
  max-width: 62ch;
  color: var(--muted);
}

.app-main{
  display:grid;
  grid-template-columns: minmax(280px, 1fr) 2fr;
  gap: 20px;
  padding: 20px;
  align-items:start;
}

.controls{
  grid-column: 1 / -1;
  background: var(--panel);
  border: 1px solid var(--stroke);
  border-radius: var(--radius);
  padding: 16px;
  display: grid;
  gap: 12px;
}
.control-row{
  display:flex;
  gap: 12px;
  align-items:center;
  flex-wrap:wrap;
}
label{ color:var(--muted); font-weight:600; }
select, input[type="search"]{
  appearance: none;
  background: var(--panel-2);
  border: 1px solid var(--stroke);
  border-radius: 12px;
  color: var(--text);
  padding: 12px 14px;
  min-width: 200px;
  outline: none;
  font-size: 15px;
}
input[type="search"]{ flex:1; min-width: 260px; }

.btn{
  border: 1px solid var(--stroke);
  background: linear-gradient(180deg, var(--panel-2), var(--panel));
  color: var(--text);
  padding: 11px 16px;
  border-radius: 12px;
  cursor:pointer;
  transition: transform .08s ease, box-shadow .2s ease, border-color .2s ease, background .2s ease;
  box-shadow: 0 2px 0 rgba(255,255,255,.6) inset, 0 8px 18px rgba(0,0,0,.06);
}
.dark .btn{ box-shadow: 0 1px 0 rgba(255,255,255,.04) inset, 0 8px 20px rgba(0,0,0,.18); }
.btn:hover{ transform: translateY(-1px); }
.btn:active{ transform: translateY(0); }
.btn.primary{
  background: linear-gradient(180deg, color-mix(in oklab, var(--brand) 86%, #fff 14%), var(--brand));
  border-color: color-mix(in oklab, var(--brand), #000 10%);
  color: white;
}

.board{
  grid-column: 1 / 2;
  background: var(--panel);
  border: 1px solid var(--stroke);
  border-radius: var(--radius);
  padding: 16px;
}
.grid{
  display:grid;
  gap: 12px;
}
.cell{
  user-select:none;
  border: 1px solid var(--stroke);
  background: linear-gradient(180deg, var(--panel-2), var(--panel));
  border-radius: 14px;
  padding: 16px;
  min-height: 110px;
  display:flex;
  align-items:center;
  justify-content:center;
  text-align:center;
  font-size: clamp(14px, 1.4vw, 18px);
  line-height: 1.35;
  cursor: pointer;
  transition: transform .06s ease, border-color .2s ease, background .2s ease, box-shadow .2s ease;
  box-shadow: 0 1px 0 rgba(255,255,255,.7) inset, 0 10px 20px rgba(0,0,0,.06);
}
.dark .cell{ box-shadow: 0 1px 0 rgba(255,255,255,.05) inset, 0 10px 24px rgba(0,0,0,.18); }
.cell:focus{ outline: 3px solid color-mix(in oklab, var(--brand) 70%, #fff 30%); outline-offset: 2px; }
.cell:hover{ transform: translateY(-1px); }
.cell.marked{
  background: linear-gradient(180deg, color-mix(in oklab, var(--brand-2) 22%, var(--panel) 78%), color-mix(in oklab, var(--brand-2) 18%, var(--panel) 82%));
  border-color: color-mix(in oklab, var(--brand-2), #000 12%);
  box-shadow: 0 0 0 1px color-mix(in oklab, var(--brand-2), #000 22%) inset, 0 16px 28px rgba(0,0,0,.08);
}

.drawer{
  grid-column: 2 / 3;
  background: var(--panel);
  border: 1px solid var(--stroke);
  border-radius: var(--radius);
  padding: 16px;
  max-height: 80vh;
  overflow:auto;
}
.drawer__header{
  display:flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 8px;
}
.drawer__content{
  display:grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}
.list-item{
  border:1px dashed var(--stroke);
  border-radius: 12px;
  padding: 12px 14px;
  background: var(--panel-2);
  font-size: 15px;
}

.app-footer{
  text-align:center;
  padding: 18px;
  color: var(--muted);
}

.modal{
  border:none;
  border-radius: 18px;
  padding: 0;
  background: transparent;
}
.modal::backdrop{ background: rgba(0,0,0,.35); }
.modal__content{
  background: var(--panel);
  border: 1px solid var(--stroke);
  border-radius: 18px;
  padding: 20px;
  min-width: min(520px, 92vw);
}
.modal__actions{ display:flex; gap: 10px; justify-content:flex-end; margin-top: 12px; }

@media (max-width: 980px){
  .app-main{
    grid-template-columns: 1fr;
  }
  .drawer__content{
    grid-template-columns: 1fr;
  }
}