/* ───────────────────────────────────────────────
   CALCUDO SOLVER — style.css
   Aesthetic: Premium puzzle book, dark slate + amber
─────────────────────────────────────────────── */

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg:           #16181d;
  --bg-panel:     #1e2028;
  --bg-panel2:    #22252f;
  --border:       #2e3240;
  --border-light: #3a3f52;
  --amber:        #e8a832;
  --amber-dim:    #b07e1e;
  --amber-glow:   rgba(232,168,50,0.12);
  --text:         #e8e4d8;
  --text-muted:   #7a8099;
  --text-dim:     #454d66;
  --cell-bg:      #1a1d24;
  --cell-hover:   #22273a;
  --cell-sel:     #2a3055;
  --cage-border:  #e8a832;
  --green:        #5cb87a;
  --red:          #c0605a;
  --blue:         #5f9be8;
  --radius:       6px;
  --radius-lg:    12px;
  --font-display: 'Playfair Display', Georgia, serif;
  --font-mono:    'DM Mono', 'Courier New', monospace;
  --font-body:    'DM Sans', sans-serif;
}

html, body {
  height: 100%;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 15px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

/* ── HEADER ──────────────────────────────────── */
.site-header {
  border-bottom: 1px solid var(--border);
  background: var(--bg-panel);
  padding: 0 32px;
}
.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 20px;
  height: 64px;
}
.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}
.logo-box {
  width: 36px;
  height: 36px;
  background: var(--amber);
  color: var(--bg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 700;
  border-radius: 4px;
}
.logo-text {
  display: flex;
  flex-direction: column;
  line-height: 1.1;
}
.logo-title {
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 700;
  color: var(--text);
  letter-spacing: 0.02em;
}
.logo-sub {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.15em;
  color: var(--amber);
  text-transform: uppercase;
}
.tagline {
  margin-left: auto;
  font-size: 13px;
  color: var(--text-muted);
  font-style: italic;
  font-family: var(--font-display);
  white-space: nowrap;
}

/* ── MODE TABS ───────────────────────────────── */
.mode-tabs {
  display: flex;
  gap: 4px;
  background: var(--bg-panel2);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 3px;
  flex-shrink: 0;
}
.mode-tab {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  border-radius: 5px;
  border: none;
  background: transparent;
  color: var(--text-muted);
  font-family: var(--font-body);
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.15s ease;
}
.mode-tab:hover { color: var(--text); }
.mode-tab.active {
  background: var(--amber);
  color: var(--bg);
}
.mode-tab.active svg { opacity: 1; }

/* ── LAYOUT ──────────────────────────────────── */
.app {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}
.main-content {
  flex: 1;
  display: flex;
  max-width: 1200px;
  width: 100%;
  margin: 0 auto;
  padding: 28px 24px;
  gap: 24px;
  align-items: flex-start;
}

/* ── PANELS ──────────────────────────────────── */
.panel {
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
}
.panel-controls {
  width: 300px;
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
}
.panel-controls.hidden { display: none; }

.panel-grid {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 28px;
  gap: 16px;
}

/* ── CONTROL SECTIONS ────────────────────────── */
.control-section {
  padding: 20px;
  border-bottom: 1px solid var(--border);
}
.control-section:last-child { border-bottom: none; }

.section-title {
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 500;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 14px;
  display: flex;
  align-items: center;
  gap: 8px;
}

/* ── SIZE BUTTONS ────────────────────────────── */
.size-buttons {
  display: flex;
  gap: 6px;
}
.size-btn {
  flex: 1;
  padding: 7px 4px;
  background: var(--bg-panel2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text-muted);
  font-family: var(--font-mono);
  font-size: 12px;
  cursor: pointer;
  transition: all 0.15s ease;
}
.size-btn:hover { border-color: var(--amber-dim); color: var(--text); }
.size-btn.active {
  background: var(--amber-glow);
  border-color: var(--amber);
  color: var(--amber);
}

/* ── CAGE BUILDER ────────────────────────────── */
.cage-builder { display: flex; flex-direction: column; gap: 12px; }
.hint {
  font-size: 12px;
  color: var(--text-muted);
  line-height: 1.6;
}
.hint strong { color: var(--text); font-weight: 500; }
.builder-row {
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.field-label {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-dim);
}
.op-buttons {
  display: flex;
  gap: 5px;
}
.op-btn {
  flex: 1;
  padding: 7px 2px;
  background: var(--bg-panel2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text-muted);
  font-family: var(--font-mono);
  font-size: 14px;
  cursor: pointer;
  transition: all 0.15s ease;
}
.op-btn:hover { border-color: var(--amber-dim); color: var(--text); }
.op-btn.active {
  background: var(--amber-glow);
  border-color: var(--amber);
  color: var(--amber);
}

.target-input {
  width: 100%;
  padding: 8px 10px;
  background: var(--bg-panel2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text);
  font-family: var(--font-mono);
  font-size: 14px;
  outline: none;
  transition: border-color 0.15s;
}
.target-input:focus { border-color: var(--amber); }
.target-input::placeholder { color: var(--text-dim); }
.target-input::-webkit-outer-spin-button,
.target-input::-webkit-inner-spin-button { -webkit-appearance: none; }
.target-input[type=number] { -moz-appearance: textfield; }

.builder-actions {
  display: flex;
  gap: 8px;
}

/* ── BUTTONS ─────────────────────────────────── */
.btn {
  padding: 9px 16px;
  border-radius: var(--radius);
  font-family: var(--font-body);
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  border: 1px solid transparent;
  transition: all 0.15s ease;
  white-space: nowrap;
}
.btn-primary {
  flex: 1;
  background: var(--amber);
  color: var(--bg);
  border-color: var(--amber);
}
.btn-primary:hover { background: #f0b840; }
.btn-primary:active { transform: scale(0.98); }

.btn-ghost {
  background: transparent;
  border-color: var(--border);
  color: var(--text-muted);
}
.btn-ghost:hover { border-color: var(--border-light); color: var(--text); }

.btn-solve {
  width: 100%;
  padding: 12px;
  background: var(--amber);
  color: var(--bg);
  border: none;
  border-radius: var(--radius);
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 700;
  cursor: pointer;
  letter-spacing: 0.02em;
  transition: all 0.2s ease;
  margin-bottom: 0;
}
.btn-solve:hover {
  background: #f0b840;
  box-shadow: 0 4px 20px rgba(232,168,50,0.3);
  transform: translateY(-1px);
}
.btn-solve:active { transform: translateY(0); }
.btn-solve:disabled {
  background: var(--bg-panel2);
  color: var(--text-dim);
  border: 1px solid var(--border);
  box-shadow: none;
  transform: none;
  cursor: not-allowed;
}

.btn-full { width: 100%; }

/* ── BADGE ───────────────────────────────────── */
.badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 18px;
  height: 18px;
  padding: 0 5px;
  background: var(--amber-glow);
  border: 1px solid var(--amber-dim);
  border-radius: 9px;
  font-family: var(--font-mono);
  font-size: 10px;
  color: var(--amber);
}

/* ── CAGE LIST ───────────────────────────────── */
.cage-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 6px;
  max-height: 200px;
  overflow-y: auto;
}
.cage-list::-webkit-scrollbar { width: 4px; }
.cage-list::-webkit-scrollbar-track { background: transparent; }
.cage-list::-webkit-scrollbar-thumb { background: var(--border-light); border-radius: 2px; }
.cage-list-empty { font-size: 12px; color: var(--text-dim); font-style: italic; }

.cage-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 7px 10px;
  background: var(--bg-panel2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 12px;
  border-left: 3px solid var(--cage-color, var(--amber));
  transition: opacity 0.15s;
}
.cage-item-label {
  font-family: var(--font-mono);
  font-weight: 500;
  color: var(--cage-color, var(--amber));
  min-width: 36px;
}
.cage-item-cells { color: var(--text-muted); flex: 1; font-size: 11px; }
.cage-item-del {
  background: none;
  border: none;
  color: var(--text-dim);
  cursor: pointer;
  padding: 2px 4px;
  border-radius: 3px;
  font-size: 14px;
  line-height: 1;
  transition: color 0.15s;
}
.cage-item-del:hover { color: var(--red); }

/* ── PROGRESS BAR ────────────────────────────── */
.progress-wrap {
  height: 6px;
  background: var(--bg-panel2);
  border-radius: 3px;
  overflow: hidden;
  border: 1px solid var(--border);
  margin-bottom: 8px;
}
.progress-bar {
  height: 100%;
  background: var(--amber);
  border-radius: 3px;
  transition: width 0.3s ease;
}
.progress-label {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text-muted);
}

/* ── SOLVE/PLAY MESSAGE ──────────────────────── */
.solve-section { display: flex; flex-direction: column; gap: 0; }
.solve-message {
  margin-top: 10px;
  padding: 10px 12px;
  border-radius: var(--radius);
  font-size: 13px;
  font-family: var(--font-mono);
  display: none;
}
.solve-message.success {
  display: block;
  background: rgba(92,184,122,0.1);
  border: 1px solid rgba(92,184,122,0.3);
  color: var(--green);
}
.solve-message.error {
  display: block;
  background: rgba(192,96,90,0.1);
  border: 1px solid rgba(192,96,90,0.3);
  color: var(--red);
}
.solve-message.info {
  display: block;
  background: var(--amber-glow);
  border: 1px solid rgba(232,168,50,0.25);
  color: var(--amber);
}

/* ── GRID ────────────────────────────────────── */
.grid-wrapper {
  display: flex;
  align-items: center;
  justify-content: center;
}
.calcudo-grid {
  display: grid;
  gap: 0;
  border: 3px solid var(--border-light);
  border-radius: 4px;
  overflow: hidden;
  /* Prevent text selection during drag */
  user-select: none;
  -webkit-user-select: none;
}

/* ── CELLS ───────────────────────────────────── */
.cell {
  position: relative;
  background: var(--cell-bg);
  border: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  user-select: none;
  -webkit-user-select: none;
  touch-action: none; /* needed for pointer events on touch */
  transition: background 0.1s ease;
}
.cell:hover { background: var(--cell-hover); }
.cell.selected { background: var(--cell-sel); }

/* Play mode: clickable empty cells pulse subtly */
.play-mode .cell.play-empty:hover {
  background: var(--cell-hover);
  outline: 1px solid var(--border-light);
}

/* Focused cell in play mode */
.cell.cell-focused {
  background: #1e2640 !important;
  box-shadow: inset 0 0 0 2px var(--amber);
  z-index: 2;
}

/* Cell value */
.cell-value {
  font-family: var(--font-display);
  font-weight: 700;
  color: var(--amber);
  line-height: 1;
  pointer-events: none;
  position: relative;
  z-index: 1;
}

/* User-entered value in play mode */
.cell-value.user-value {
  color: var(--blue);
}

/* Hinted cell highlight */
.cell.hint-flash {
  animation: hint-flash 0.7s ease both;
}
@keyframes hint-flash {
  0%   { background: rgba(232,168,50,0.4); }
  60%  { background: rgba(232,168,50,0.15); }
  100% { background: var(--cell-bg); }
}

/* Cage label (top-left corner of cage) */
.cell-cage-label {
  position: absolute;
  top: 3px;
  left: 4px;
  font-family: var(--font-mono);
  font-weight: 500;
  color: var(--cage-label-color, var(--text-muted));
  pointer-events: none;
  line-height: 1;
  z-index: 2;
}

/* Cage border rendering */
.cell.cage-border-top    { border-top:    2.5px solid var(--cell-cage-border, var(--amber)); }
.cell.cage-border-right  { border-right:  2.5px solid var(--cell-cage-border, var(--amber)); }
.cell.cage-border-bottom { border-bottom: 2.5px solid var(--cell-cage-border, var(--amber)); }
.cell.cage-border-left   { border-left:   2.5px solid var(--cell-cage-border, var(--amber)); }

/* Grid hint text */
.grid-hint {
  font-size: 12px;
  color: var(--text-dim);
  text-align: center;
  font-style: italic;
}

/* ── SOLVED STATE ────────────────────────────── */
.cell.solved .cell-value {
  animation: pop-in 0.25s ease both;
}
@keyframes pop-in {
  from { transform: scale(0.4); opacity: 0; }
  to   { transform: scale(1);   opacity: 1; }
}

/* ── FOOTER ──────────────────────────────────── */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 14px 32px;
  text-align: center;
  background: var(--bg-panel);
}
.site-footer p {
  font-size: 12px;
  color: var(--text-dim);
  font-family: var(--font-mono);
}
.footer-link {
  color: var(--amber);
  text-decoration: none;
  transition: color 0.15s;
}
.footer-link:hover {
  color: #f0b840;
  text-decoration: underline;
}

/* ── RESPONSIVE ──────────────────────────────── */
@media (max-width: 800px) {
  .main-content {
    flex-direction: column;
    padding: 16px;
  }
  .panel-controls { width: 100%; }
  .tagline { display: none; }
  .mode-tabs { margin-left: auto; }
}