/* ═══════════════════════════════════════════════════
   MAZE Generator - Main Styles
   Design: Dark technical aesthetic with neon accents
   ═══════════════════════════════════════════════════ */

@import url('https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@300;400;500;600;700&family=JetBrains+Mono:wght@400;500&display=swap');

/* ─── CSS Variables ─── */
:root {
  --bg-primary: #0d1117;
  --bg-secondary: #161b22;
  --bg-tertiary: #21262d;
  --bg-card: #1c2128;
  --border: #30363d;
  --border-bright: #444c56;

  --accent-blue: #4FC3F7;
  --accent-green: #66BB6A;
  --accent-yellow: #FFD54F;
  --accent-orange: #FFB74D;
  --accent-purple: #CE93D8;

  --text-primary: #e6edf3;
  --text-secondary: #8b949e;
  --text-muted: #484f58;

  --font-ui: 'Space Grotesk', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', 'Courier New', monospace;

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;

  --shadow-sm: 0 1px 3px rgba(0,0,0,0.4);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.5);
  --shadow-lg: 0 8px 32px rgba(0,0,0,0.6);
  --shadow-glow-blue: 0 0 20px rgba(79, 195, 247, 0.2);
  --shadow-glow-green: 0 0 20px rgba(102, 187, 106, 0.2);

  --transition: 0.18s ease;
}

/* ─── Reset & Base ─── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { height: 100%; }

body {
  font-family: var(--font-ui);
  background: var(--bg-primary);
  color: var(--text-primary);
  height: 100%;
  overflow: hidden;
  font-size: 14px;
  line-height: 1.5;
}

/* ─── App Shell ─── */
#app {
  display: grid;
  grid-template-rows: 56px 1fr;
  grid-template-columns: 300px 1fr;
  height: 100vh;
  overflow: hidden;
}

/* ─── Header ─── */
#header {
  grid-column: 1 / -1;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  padding: 0 20px;
  gap: 16px;
  z-index: 10;
}

.header-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -0.5px;
}

.logo-icon {
  width: 32px;
  height: 32px;
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
}

.logo-text { color: var(--text-primary); }
.logo-sub { color: var(--text-secondary); font-weight: 400; font-size: 13px; margin-left: 4px; }

.header-tabs {
  display: flex;
  gap: 4px;
  margin-left: auto;
  background: var(--bg-tertiary);
  padding: 4px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
}

.tab-btn {
  padding: 6px 16px;
  border: none;
  background: transparent;
  color: var(--text-secondary);
  font-family: var(--font-ui);
  font-size: 13px;
  font-weight: 500;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition);
}

.tab-btn:hover { color: var(--text-primary); background: var(--bg-card); }
.tab-btn.active {
  background: var(--accent-blue);
  color: #000;
  font-weight: 600;
}

/* ─── Sidebar ─── */
#sidebar {
  background: var(--bg-secondary);
  border-right: 1px solid var(--border);
  overflow-y: auto;
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  scrollbar-width: thin;
  scrollbar-color: var(--border) transparent;
}

#sidebar::-webkit-scrollbar { width: 4px; }
#sidebar::-webkit-scrollbar-track { background: transparent; }
#sidebar::-webkit-scrollbar-thumb { background: var(--border); border-radius: 2px; }

/* ─── Panel Cards ─── */
.panel {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 14px;
}

.panel-header {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 12px;
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.8px;
  color: var(--text-secondary);
}

.panel-header-icon {
  width: 20px;
  height: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
}

/* ─── Form Elements ─── */
.field {
  margin-bottom: 10px;
}

.field:last-child { margin-bottom: 0; }

label {
  display: block;
  font-size: 12px;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: 5px;
  letter-spacing: 0.3px;
}

input[type="text"],
input[type="number"],
select {
  width: 100%;
  padding: 8px 10px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-family: var(--font-ui);
  font-size: 13px;
  transition: var(--transition);
  outline: none;
}

input[type="text"]:focus,
input[type="number"]:focus,
select:focus {
  border-color: var(--accent-blue);
  box-shadow: 0 0 0 2px rgba(79, 195, 247, 0.15);
}

select {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath d='M1 1l5 5 5-5' stroke='%238b949e' stroke-width='1.5' fill='none' stroke-linecap='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 10px center;
  padding-right: 28px;
  cursor: pointer;
}

select option { background: var(--bg-tertiary); }

.input-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}

/* ─── Segment Control (Maze Type) ─── */
.segment-control {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 4px;
  background: var(--bg-tertiary);
  padding: 4px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
}

.segment-btn {
  padding: 7px 4px;
  border: none;
  background: transparent;
  color: var(--text-secondary);
  font-family: var(--font-ui);
  font-size: 12px;
  font-weight: 500;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition);
  text-align: center;
}

.segment-btn:hover { color: var(--text-primary); }
.segment-btn.active {
  background: var(--bg-card);
  color: var(--accent-blue);
  font-weight: 600;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-bright);
}

/* ─── Difficulty Pills ─── */
.difficulty-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 4px;
}

.diff-btn {
  padding: 7px 4px;
  border: 1px solid var(--border);
  background: var(--bg-tertiary);
  color: var(--text-secondary);
  font-family: var(--font-ui);
  font-size: 11px;
  font-weight: 500;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition);
  text-align: center;
}

.diff-btn:hover { border-color: var(--border-bright); color: var(--text-primary); }
.diff-btn.active[data-diff="easy"] { background: rgba(102,187,106,0.15); border-color: var(--accent-green); color: var(--accent-green); }
.diff-btn.active[data-diff="medium"] { background: rgba(79,195,247,0.15); border-color: var(--accent-blue); color: var(--accent-blue); }
.diff-btn.active[data-diff="hard"] { background: rgba(255,213,79,0.15); border-color: var(--accent-yellow); color: var(--accent-yellow); }
.diff-btn.active[data-diff="expert"] { background: rgba(255,183,77,0.15); border-color: var(--accent-orange); color: var(--accent-orange); }

/* ─── Primary Button ─── */
.btn-primary {
  width: 100%;
  padding: 11px;
  background: linear-gradient(135deg, var(--accent-blue), #0288d1);
  border: none;
  border-radius: var(--radius-md);
  color: #000;
  font-family: var(--font-ui);
  font-size: 14px;
  font-weight: 700;
  cursor: pointer;
  transition: var(--transition);
  letter-spacing: 0.3px;
  box-shadow: 0 2px 12px rgba(79,195,247,0.3);
}

.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 20px rgba(79,195,247,0.4);
}

.btn-primary:active { transform: translateY(0); }

.btn-primary:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
}

/* ─── Secondary Button ─── */
.btn-secondary {
  padding: 8px 12px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-family: var(--font-ui);
  font-size: 12px;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
}

.btn-secondary:hover {
  border-color: var(--border-bright);
  background: var(--bg-card);
}

/* ─── Export Buttons ─── */
.export-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 6px;
}

.btn-export {
  padding: 9px 8px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-tertiary);
  color: var(--text-secondary);
  font-family: var(--font-ui);
  font-size: 11px;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 5px;
}

.btn-export:hover {
  border-color: var(--accent-blue);
  color: var(--accent-blue);
  background: rgba(79,195,247,0.08);
}

.btn-export .icon { font-size: 13px; }
.btn-export.pdf-btn:hover { border-color: var(--accent-orange); color: var(--accent-orange); background: rgba(255,183,77,0.08); }
.btn-export.full-row { grid-column: 1 / -1; }

/* ─── Solution Control ─── */
.solution-controls {
  display: flex;
  gap: 6px;
}

.btn-solve {
  flex: 1;
  padding: 9px;
  background: rgba(102,187,106,0.12);
  border: 1px solid var(--accent-green);
  border-radius: var(--radius-sm);
  color: var(--accent-green);
  font-family: var(--font-ui);
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
}

.btn-solve:hover { background: rgba(102,187,106,0.2); }
.btn-solve.active { background: var(--accent-green); color: #000; }

.btn-hide-solve {
  padding: 9px 12px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-family: var(--font-ui);
  font-size: 12px;
  cursor: pointer;
  transition: var(--transition);
}

.btn-hide-solve:hover { border-color: var(--border-bright); color: var(--text-primary); }

/* ─── Stats ─── */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 6px;
}

.stat-item {
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 8px 10px;
}

.stat-label {
  font-size: 10px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 2px;
}

.stat-value {
  font-size: 16px;
  font-weight: 700;
  font-family: var(--font-mono);
  color: var(--accent-blue);
}

.stat-value.green { color: var(--accent-green); }
.stat-value.yellow { color: var(--accent-yellow); }
.stat-value.orange { color: var(--accent-orange); }

/* ─── Canvas Area ─── */
#main-area {
  display: flex;
  flex-direction: column;
  overflow: hidden;
  background: var(--bg-primary);
}

/* ─── View Panels ─── */
.view-panel {
  display: none;
  flex: 1;
  flex-direction: column;
  overflow: hidden;
}

.view-panel.active { display: flex; }

/* ─── Canvas Container ─── */
#canvas-container {
  flex: 1;
  position: relative;
  overflow: hidden;
  background: var(--bg-primary);
  cursor: grab;
}

#canvas-container.grabbing { cursor: grabbing; }

#maze-canvas {
  position: absolute;
  top: 0;
  left: 0;
  image-rendering: crisp-edges;
}

/* ─── Canvas Toolbar ─── */
.canvas-toolbar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
}

.toolbar-group {
  display: flex;
  align-items: center;
  gap: 4px;
}

.toolbar-btn {
  padding: 6px 10px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-family: var(--font-ui);
  font-size: 12px;
  cursor: pointer;
  transition: var(--transition);
}

.toolbar-btn:hover { border-color: var(--border-bright); color: var(--text-primary); }

.zoom-display {
  font-size: 12px;
  font-family: var(--font-mono);
  color: var(--text-secondary);
  min-width: 44px;
  text-align: center;
}

.toolbar-sep {
  width: 1px;
  height: 20px;
  background: var(--border);
}

.toolbar-info {
  margin-left: auto;
  font-size: 12px;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

/* ─── Empty State ─── */
#empty-state {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
  pointer-events: none;
}

.empty-icon {
  font-size: 64px;
  opacity: 0.15;
  line-height: 1;
}

.empty-title {
  font-size: 20px;
  font-weight: 600;
  color: var(--text-muted);
}

.empty-sub {
  font-size: 13px;
  color: var(--text-muted);
  opacity: 0.7;
}

.empty-state-hint {
  display: flex;
  align-items: center;
  gap: 6px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 8px 14px;
  font-size: 12px;
  color: var(--text-secondary);
  margin-top: 8px;
  pointer-events: none;
}

/* ─── Batch Tab ─── */
#batch-panel {
  padding: 24px;
  overflow-y: auto;
  max-width: 700px;
  margin: 0 auto;
  width: 100%;
}

.batch-header {
  margin-bottom: 24px;
}

.batch-title {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 6px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.batch-sub { font-size: 13px; color: var(--text-secondary); }

.batch-form {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 20px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
  margin-bottom: 16px;
}

.batch-form .full-row { grid-column: 1 / -1; }

.batch-actions {
  display: flex;
  gap: 10px;
}

.btn-batch {
  flex: 1;
  padding: 12px;
  background: linear-gradient(135deg, var(--accent-green), #43a047);
  border: none;
  border-radius: var(--radius-md);
  color: #000;
  font-family: var(--font-ui);
  font-size: 14px;
  font-weight: 700;
  cursor: pointer;
  transition: var(--transition);
  box-shadow: 0 2px 12px rgba(102,187,106,0.3);
}

.btn-batch:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 20px rgba(102,187,106,0.4);
}

.btn-batch:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
}

/* ─── Progress ─── */
.progress-section {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 16px;
  display: none;
}

.progress-section.visible { display: block; }

.progress-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 10px;
  font-size: 13px;
}

.progress-label { font-weight: 600; }
.progress-count { color: var(--text-secondary); font-family: var(--font-mono); }

.progress-bar-track {
  height: 8px;
  background: var(--bg-tertiary);
  border-radius: 4px;
  overflow: hidden;
  margin-bottom: 10px;
}

.progress-bar-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent-green), var(--accent-blue));
  border-radius: 4px;
  transition: width 0.3s ease;
  width: 0%;
}

.progress-log {
  font-size: 11px;
  color: var(--text-muted);
  font-family: var(--font-mono);
  max-height: 80px;
  overflow-y: auto;
  scrollbar-width: thin;
}

/* ─── Checkbox ─── */
.checkbox-field {
  display: flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
}

.checkbox-field input[type="checkbox"] {
  width: 16px;
  height: 16px;
  accent-color: var(--accent-blue);
  cursor: pointer;
}

.checkbox-field span {
  font-size: 12px;
  color: var(--text-secondary);
}

/* ─── Toast Notification ─── */
#toast-container {
  position: fixed;
  bottom: 20px;
  right: 20px;
  z-index: 1000;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.toast {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 10px 16px;
  font-size: 13px;
  box-shadow: var(--shadow-lg);
  animation: toastIn 0.2s ease forwards;
  display: flex;
  align-items: center;
  gap: 8px;
  max-width: 300px;
}

.toast.success { border-color: var(--accent-green); }
.toast.error { border-color: #f85149; color: #f85149; }
.toast.info { border-color: var(--accent-blue); }

@keyframes toastIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ─── Loading Overlay ─── */
#loading-overlay {
  position: absolute;
  inset: 0;
  background: rgba(13,17,23,0.8);
  backdrop-filter: blur(4px);
  display: none;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 12px;
  z-index: 50;
}

#loading-overlay.visible { display: flex; }

.spinner {
  width: 36px;
  height: 36px;
  border: 3px solid var(--border);
  border-top-color: var(--accent-blue);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin { to { transform: rotate(360deg); } }

.loading-text {
  font-size: 13px;
  color: var(--text-secondary);
  font-family: var(--font-mono);
}

/* ─── Scrollbar global ─── */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--border-bright); }

/* ─── Responsive ─── */
@media (max-width: 900px) {
  #app {
    grid-template-columns: 260px 1fr;
  }
}

@media (max-width: 680px) {
  #app {
    grid-template-rows: 56px auto 1fr;
    grid-template-columns: 1fr;
  }
  #sidebar {
    border-right: none;
    border-bottom: 1px solid var(--border);
    max-height: 240px;
  }
}