/* ═══════════════════════════════════════════════
   styles.css (Pro Dark Mode)
   ═══════════════════════════════════════════════ */
:root {
  --bg-main: #050b14;
  --bg-card: #0f172a;
  --bg-card-hover: #1e293b;
  --bg-input: #020617;
  
  --border: #1e293b;
  --border-focus: #0ea5e9;
  
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  
  --primary: #0ea5e9;
  --primary-glow: rgba(14, 165, 233, 0.4);
  --danger: #ef4444;
  --success: #10b981;
  --warning: #f59e0b;
  
  --tile-bg: linear-gradient(145deg, #1e293b, #0f172a);
  --tile-border: #334155;
  --tile-text: #e2e8f0;
  
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 24px;
}

body {
  font-family: "Kanit", sans-serif;
  background: var(--bg-main);
  background-image: radial-gradient(circle at top, rgba(14, 165, 233, 0.05), transparent 50%);
  color: var(--text-main);
  margin: 0;
  padding-bottom: 40px;
  min-height: 100vh;
}

/* Layout */
.main-wrapper {
  display: flex;
  justify-content: center;
  align-items: flex-start;
  gap: 24px;
  padding: 24px;
  max-width: 1100px;
  margin: 0 auto;
}

.container {
  background: var(--bg-card);
  padding: 24px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  box-shadow: 0 20px 40px rgba(0,0,0,0.6);
  width: 100%;
  max-width: 480px;
}

/* Typography */
.section-label {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 8px;
  display: flex;
  justify-content: space-between;
}
.section-label span { font-size: 11px; text-transform: none; color: var(--primary); }
.mt-3 { margin-top: 24px; }

/* Mode Toggle */
.mode-toggle {
  display: flex;
  background: var(--bg-input);
  border-radius: var(--radius-md);
  padding: 6px;
  margin-bottom: 24px;
  border: 1px solid var(--border);
}
.mode-toggle button {
  flex: 1;
  background: transparent;
  border: none;
  color: var(--text-muted);
  padding: 10px;
  border-radius: 8px;
  font-weight: 600;
  cursor: pointer;
  transition: 0.2s;
  font-family: "Kanit", sans-serif;
}
.mode-toggle button.active {
  background: var(--bg-card);
  color: var(--primary);
  box-shadow: 0 4px 10px rgba(0,0,0,0.3);
}

/* Rack Input */
.show-pawn-input {
  background: var(--bg-input);
  border: 2px dashed var(--border);
  border-radius: var(--radius-md);
  min-height: 65px;
  padding: 10px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: center;
  align-items: center;
  cursor: pointer;
  transition: 0.3s;
  margin-bottom: 20px;
}
.show-pawn-input.targeting {
  border-color: var(--primary);
  background: rgba(14, 165, 233, 0.05);
  box-shadow: 0 0 15px var(--primary-glow);
}

/* Tiles (Generic) */
.pawn-slot {
  position: relative;
  min-width: 42px;
  height: 42px;
  background: var(--tile-bg);
  border: 1px solid var(--tile-border);
  border-radius: var(--radius-sm);
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: 20px;
  font-weight: 700;
  color: var(--tile-text);
  box-shadow: 0 4px 6px rgba(0,0,0,0.4);
}
.tile-pt {
  position: absolute;
  bottom: 2px;
  right: 4px;
  font-size: 10px;
  color: var(--text-muted);
  font-weight: normal;
}

/* Filter Card */
.filter-card {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: var(--bg-input);
  padding: 12px 16px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  margin-bottom: 24px;
}
.filter-card label { font-size: 14px; color: var(--text-muted); }
.input-wrapper { display: flex; align-items: center; gap: 8px; }
.input-wrapper input {
  width: 50px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-main);
  padding: 6px;
  border-radius: 6px;
  text-align: center;
  font-weight: bold;
  font-family: "Kanit", sans-serif;
}
.input-wrapper input:focus { outline: none; border-color: var(--primary); }
.input-wrapper span { font-size: 13px; color: var(--text-muted); }

/* Mode 2 Elements */
.info-banner {
  display: flex;
  align-items: center;
  gap: 10px;
  background: rgba(14, 165, 233, 0.1);
  color: var(--primary);
  padding: 12px;
  border-radius: var(--radius-md);
  border: 1px solid rgba(14, 165, 233, 0.2);
  font-size: 13px;
  margin-bottom: 16px;
}
.seq-row {
  display: flex;
  align-items: center;
  gap: 8px;
  background: var(--bg-input);
  padding: 14px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  margin-bottom: 10px;
  flex-wrap: wrap;
}
.empty-input {
  width: 44px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-main);
  padding: 6px;
  border-radius: 6px;
  text-align: center;
  font-weight: bold;
  font-family: "Kanit", sans-serif;
}
.tile-slot {
  position: relative;
  min-width: 42px;
  height: 42px;
  border: 1px dashed var(--border);
  border-radius: var(--radius-sm);
  display: flex;
  justify-content: center;
  align-items: center;
  font-weight: bold;
  font-size: 18px;
  cursor: pointer;
  background: var(--bg-card);
  transition: 0.2s;
}
.tile-slot:hover { border-color: var(--text-muted); }
.tile-slot.selected { border: 1px solid var(--primary); box-shadow: 0 0 10px var(--primary-glow); }
.tile-slot.filled { border: 1px solid var(--success); background: rgba(16, 185, 129, 0.1); color: var(--success); }

.btn-action {
  padding: 8px 12px; border: none; border-radius: 6px; cursor: pointer; font-weight: 600; font-size: 13px; color: #fff; font-family: "Kanit", sans-serif; transition: 0.2s;
}
.btn-action:active { transform: scale(0.95); }
.btn-action.add { background: var(--primary); }
.btn-action.remove { background: var(--danger); }
.seg-controls { display: flex; gap: 8px; margin: 12px 0 24px; }

/* Preview Board */
.seq-preview-wrap {
  display: flex; gap: 6px; flex-wrap: wrap;
  background: var(--bg-input); padding: 14px; border-radius: var(--radius-md); border: 1px solid var(--border);
}
.preview-tile-box {
  min-width: 38px; height: 38px; border-radius: 6px; display: flex; justify-content: center; align-items: center; font-weight: bold; font-size: 13px; position: relative;
}
.preview-tile-box.is-fixed { background: var(--warning); color: #000; border: none; }
.preview-tile-box.is-empty { border: 1px solid var(--border); cursor: pointer; color: #fff; user-select: none; }
.bonus-p1 { background: #334155; }
.bonus-p2 { background: #10b981; }
.bonus-p3 { background: #3b82f6; }
.bonus-e2 { background: #f59e0b; }
.bonus-e3 { background: #ef4444; }

/* Pawn Pad Grid */
.pawn {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 8px;
}
.pawn-btn-wrap {
  position: relative;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: 0.2s;
  box-shadow: 0 4px 6px rgba(0,0,0,0.3);
}
.pawn-btn-wrap:hover { background: var(--bg-card-hover); border-color: var(--text-muted); }
.pawn-btn-wrap:active { transform: translateY(2px); box-shadow: 0 1px 2px rgba(0,0,0,0.3); }
.pawn-btn-wrap.zero { grid-column: span 2; }
.pawn-btn-wrap input {
  width: 100%; height: 55px; background: transparent; border: none; color: var(--text-main);
  font-size: 20px; font-weight: 700; pointer-events: none; font-family: 'Kanit', sans-serif;
}
.pad-pt { position: absolute; bottom: 4px; right: 6px; font-size: 11px; color: var(--text-muted); }

/* Controls */
.control-grid {
  display: grid;
  grid-template-columns: 1fr 1fr 2fr;
  gap: 12px;
  margin-top: 24px;
}
.btn-ctrl {
  padding: 16px;
  border: none;
  border-radius: var(--radius-md);
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  color: white;
  transition: 0.2s;
  font-family: 'Kanit', sans-serif;
}
.btn-ctrl:active { transform: scale(0.96); }
.btn-ctrl.back { background: var(--bg-card-hover); border: 1px solid var(--border); }
.btn-ctrl.clear { background: rgba(239, 68, 68, 0.1); color: var(--danger); border: 1px solid rgba(239, 68, 68, 0.3); }
.btn-ctrl.submit { background: var(--primary); box-shadow: 0 4px 15px var(--primary-glow); }
.btn-ctrl.submit:hover { background: #0284c7; }

/* Solutions Panel */
.solutions-container {
  background: var(--bg-card);
  padding: 24px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  width: 100%;
  max-width: 480px;
  height: 850px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 12px;
  box-shadow: 0 20px 40px rgba(0,0,0,0.6);
}
.empty-state {
  display: flex; flex-direction: column; align-items: center; justify-content: center; height: 100%; color: var(--text-muted); text-align: center; gap: 12px;
}

.solution-item {
  background: var(--bg-input);
  border: 1px solid var(--border);
  padding: 16px 20px;
  border-radius: var(--radius-md);
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: 0.2s;
}
.solution-item:hover { border-color: rgba(14, 165, 233, 0.3); background: #0b1426; }

/* Mathematical Token Styling */
.sol-num { color: var(--text-main); font-weight: 500; font-size: 20px; letter-spacing: 1px; }
.sol-op { color: var(--primary); font-weight: bold; font-size: 20px; margin: 0 4px; }
.sol-eq { color: var(--success); font-weight: bold; font-size: 20px; margin: 0 6px; }

.solution-meta { display: flex; flex-direction: column; align-items: flex-end; gap: 6px; }
.solution-score { color: var(--warning); font-weight: bold; font-size: 16px; }
.badge { font-size: 11px; padding: 4px 8px; border-radius: 6px; font-weight: 600; letter-spacing: 0.05em; }
.badge.bingo { background: var(--success); color: #000; }
.badge.left { background: var(--bg-card-hover); color: var(--text-muted); border: 1px solid var(--border); }

.show-more-btn {
  background: var(--bg-card-hover); border: 1px solid var(--border); color: var(--text-main);
  padding: 14px; border-radius: var(--radius-md); width: 100%; cursor: pointer; font-weight: bold; margin-top: 10px;
  font-family: 'Kanit', sans-serif; transition: 0.2s;
}
.show-more-btn:hover { background: #334155; }

/* Loading Overlay */
.loading-overlay { display: none; position: fixed; inset: 0; background: rgba(5, 11, 20, 0.85); backdrop-filter: blur(8px); z-index: 10000; justify-content: center; align-items: center; }
.loading-overlay.active { display: flex; }
.loading-card { background: var(--bg-card); padding: 40px; border-radius: var(--radius-lg); text-align: center; border: 1px solid var(--border); width: 320px; box-shadow: 0 20px 40px rgba(0,0,0,0.8); }
.spinner { width: 48px; height: 48px; border: 4px solid var(--border); border-top-color: var(--primary); border-radius: 50%; animation: spin 1s linear infinite; margin: 0 auto 24px; }
.loading-pct { font-size: 42px; font-weight: bold; color: var(--text-main); margin-bottom: 20px; }
.loading-bar-track { width: 100%; height: 6px; background: var(--bg-input); border-radius: 10px; overflow: hidden; margin-bottom: 12px; }
.loading-bar-fill { height: 100%; width: 0%; background: var(--primary); transition: width 0.2s; box-shadow: 0 0 10px var(--primary-glow); }
.loading-detail { font-size: 13px; color: var(--text-muted); }
@keyframes spin { to { transform: rotate(360deg); } }

/* Scrollbar */
::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: #334155; border-radius: 10px; }
::-webkit-scrollbar-thumb:hover { background: #475569; }

/* Responsive */
@media (max-width: 900px) {
  .main-wrapper { flex-direction: column; align-items: center; padding: 16px; }
  .container { max-width: 100%; }
  .solutions-container { height: 500px; max-width: 100%; }
}