/* ===== ALGORITHM VISUALIZER — STYLE.CSS ===== */

@import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@300;400;600;700&family=Syne:wght@400;600;700;800&display=swap');

/* ===== CSS VARIABLES ===== */
:root {
  --bg-primary: #0a0a0f;
  --bg-secondary: #0f0f1a;
  --bg-card: #13131f;
  --bg-elevated: #1a1a2e;

  --accent-cyan: #00f5d4;
  --accent-purple: #7c3aed;
  --accent-pink: #f472b6;
  --accent-orange: #fb923c;
  --accent-yellow: #fbbf24;
  --accent-green: #22c55e;
  --accent-red: #ef4444;
  --accent-blue: #3b82f6;

  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #475569;

  --border: rgba(255,255,255,0.06);
  --border-accent: rgba(0,245,212,0.3);

  --glow-cyan: 0 0 20px rgba(0,245,212,0.4);
  --glow-purple: 0 0 20px rgba(124,58,237,0.4);

  --radius: 12px;
  --radius-lg: 20px;
  --transition: 0.2s cubic-bezier(0.4,0,0.2,1);
}

/* ===== RESET & BASE ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: 'Syne', sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  line-height: 1.6;
  overflow-x: hidden;
}

/* ===== BACKGROUND GRID ===== */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(rgba(0,245,212,0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0,245,212,0.03) 1px, transparent 1px);
  background-size: 40px 40px;
  pointer-events: none;
  z-index: 0;
}

/* ===== NAVBAR ===== */
.navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  background: rgba(10,10,15,0.85);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
  padding: 0 2rem;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  font-family: 'JetBrains Mono', monospace;
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--accent-cyan);
  letter-spacing: -0.5px;
}

.nav-logo span {
  color: var(--text-primary);
}

.logo-icon {
  width: 32px;
  height: 32px;
  background: linear-gradient(135deg, var(--accent-cyan), var(--accent-purple));
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  font-weight: 700;
  color: #000;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
  list-style: none;
}

.nav-links a {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  border-radius: 8px;
  text-decoration: none;
  color: var(--text-secondary);
  font-size: 0.875rem;
  font-weight: 600;
  transition: var(--transition);
  white-space: nowrap;
}

.nav-links a:hover,
.nav-links a.active {
  background: rgba(0,245,212,0.08);
  color: var(--accent-cyan);
}

/* ===== PAGE LAYOUT ===== */
.page {
  padding-top: 64px;
  min-height: 100vh;
  position: relative;
  z-index: 1;
}

.container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 2rem;
}

/* ===== PAGE HEADER ===== */
.page-header {
  padding: 3rem 0 2rem;
  text-align: center;
}

.page-header h1 {
  font-size: clamp(2rem, 5vw, 3.5rem);
  font-weight: 800;
  letter-spacing: -1px;
  margin-bottom: 0.5rem;
  background: linear-gradient(135deg, var(--text-primary) 0%, var(--accent-cyan) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.page-header p {
  color: var(--text-secondary);
  font-size: 1.1rem;
  max-width: 600px;
  margin: 0 auto;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.9rem;
}

/* ===== ALGORITHM SELECTOR ===== */
.algo-selector {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  justify-content: center;
  margin: 1.5rem 0;
}

.algo-btn {
  padding: 8px 18px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--bg-card);
  color: var(--text-secondary);
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.8rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
}

.algo-btn:hover {
  border-color: var(--border-accent);
  color: var(--accent-cyan);
}

.algo-btn.active {
  background: rgba(0,245,212,0.1);
  border-color: var(--accent-cyan);
  color: var(--accent-cyan);
  box-shadow: var(--glow-cyan);
}

/* ===== CONTROL PANEL ===== */
.control-panel {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  margin-bottom: 1.5rem;
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  align-items: center;
  justify-content: space-between;
}

.control-group {
  display: flex;
  align-items: center;
  gap: 10px;
}

.control-label {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 1px;
  white-space: nowrap;
}

/* ===== BUTTONS ===== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 20px;
  border-radius: 8px;
  border: none;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.8rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  white-space: nowrap;
}

.btn-primary {
  background: var(--accent-cyan);
  color: #000;
}

.btn-primary:hover {
  background: #00d4b8;
  transform: translateY(-1px);
  box-shadow: var(--glow-cyan);
}

.btn-secondary {
  background: var(--bg-elevated);
  color: var(--text-primary);
  border: 1px solid var(--border);
}

.btn-secondary:hover {
  border-color: var(--border-accent);
  color: var(--accent-cyan);
}

.btn-danger {
  background: rgba(239,68,68,0.1);
  color: var(--accent-red);
  border: 1px solid rgba(239,68,68,0.3);
}

.btn-danger:hover {
  background: rgba(239,68,68,0.2);
}

.btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
  transform: none !important;
}

/* ===== SLIDERS ===== */
.slider {
  -webkit-appearance: none;
  width: 120px;
  height: 4px;
  border-radius: 2px;
  background: var(--bg-elevated);
  outline: none;
  cursor: pointer;
}

.slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--accent-cyan);
  cursor: pointer;
  box-shadow: var(--glow-cyan);
  transition: var(--transition);
}

.slider::-webkit-slider-thumb:hover {
  transform: scale(1.2);
}

/* ===== CANVAS CONTAINER ===== */
.canvas-container {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  position: relative;
}

canvas {
  display: block;
  width: 100%;
}

/* ===== STATS BAR ===== */
.stats-bar {
  display: flex;
  gap: 2rem;
  margin-top: 1rem;
  flex-wrap: wrap;
}

.stat {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.stat-label {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--text-muted);
}

.stat-value {
  font-family: 'JetBrains Mono', monospace;
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--accent-cyan);
}

/* ===== COMPLEXITY BADGE ===== */
.complexity-info {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem 1.5rem;
  margin-top: 1.5rem;
  display: flex;
  gap: 2rem;
  flex-wrap: wrap;
  align-items: center;
}

.complexity-item {
  display: flex;
  align-items: center;
  gap: 8px;
}

.complexity-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  font-family: 'JetBrains Mono', monospace;
}

.complexity-value {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--accent-yellow);
}

/* ===== LEGEND ===== */
.legend {
  display: flex;
  gap: 1.5rem;
  flex-wrap: wrap;
  align-items: center;
  margin-top: 1rem;
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 6px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.75rem;
  color: var(--text-secondary);
}

.legend-dot {
  width: 12px;
  height: 12px;
  border-radius: 3px;
  flex-shrink: 0;
}

/* ===== GRID CELLS (Pathfinding) ===== */
#pathfinding-grid {
  display: grid;
  gap: 1px;
  background: var(--bg-elevated);
  border-radius: var(--radius);
  overflow: hidden;
  user-select: none;
}

.grid-cell {
  width: 28px;
  height: 28px;
  background: var(--bg-secondary);
  cursor: pointer;
  transition: background 0.1s;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 10px;
}

.grid-cell.wall { background: #1e293b; }
.grid-cell.start { background: var(--accent-green); }
.grid-cell.end { background: var(--accent-red); }
.grid-cell.visited { background: rgba(124,58,237,0.4); }
.grid-cell.path { background: var(--accent-cyan); }
.grid-cell.frontier { background: rgba(0,245,212,0.2); }

/* ===== GRAPH CANVAS ===== */
#graph-canvas {
  cursor: crosshair;
  border-radius: var(--radius-lg);
}

/* ===== INPUT FIELDS ===== */
.input-field {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text-primary);
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.875rem;
  padding: 8px 12px;
  outline: none;
  width: 120px;
  transition: var(--transition);
}

.input-field:focus {
  border-color: var(--accent-cyan);
  box-shadow: 0 0 0 2px rgba(0,245,212,0.15);
}

/* ===== SELECT ===== */
select.input-field {
  cursor: pointer;
}

/* ===== STATUS MESSAGE ===== */
.status-msg {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.8rem;
  padding: 8px 14px;
  border-radius: 8px;
  background: rgba(0,245,212,0.08);
  border: 1px solid rgba(0,245,212,0.2);
  color: var(--accent-cyan);
  min-width: 200px;
  text-align: center;
}

.status-msg.error {
  background: rgba(239,68,68,0.08);
  border-color: rgba(239,68,68,0.2);
  color: var(--accent-red);
}

.status-msg.success {
  background: rgba(34,197,94,0.08);
  border-color: rgba(34,197,94,0.2);
  color: var(--accent-green);
}

/* ===== HOME PAGE ===== */
.hero {
  min-height: calc(100vh - 64px);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 4rem 2rem;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  border-radius: 999px;
  background: rgba(0,245,212,0.08);
  border: 1px solid rgba(0,245,212,0.2);
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.75rem;
  color: var(--accent-cyan);
  margin-bottom: 2rem;
  letter-spacing: 1px;
  text-transform: uppercase;
}

.hero h1 {
  font-size: clamp(3rem, 8vw, 6rem);
  font-weight: 800;
  letter-spacing: -3px;
  line-height: 0.95;
  margin-bottom: 1.5rem;
}

.hero h1 .line1 {
  display: block;
  color: var(--text-primary);
}

.hero h1 .line2 {
  display: block;
  background: linear-gradient(135deg, var(--accent-cyan), var(--accent-purple));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero p {
  color: var(--text-secondary);
  font-size: 1.1rem;
  max-width: 550px;
  margin: 0 auto 3rem;
  line-height: 1.7;
}

.hero-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1rem;
  max-width: 960px;
  width: 100%;
  margin-top: 3rem;
}

.hero-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  text-decoration: none;
  transition: var(--transition);
  text-align: left;
  position: relative;
  overflow: hidden;
}

.hero-card::before {
  content: '';
  position: absolute;
  inset: 0;
  opacity: 0;
  transition: opacity 0.3s;
}

.hero-card:nth-child(1)::before { background: radial-gradient(circle at top left, rgba(0,245,212,0.08), transparent 60%); }
.hero-card:nth-child(2)::before { background: radial-gradient(circle at top left, rgba(124,58,237,0.08), transparent 60%); }
.hero-card:nth-child(3)::before { background: radial-gradient(circle at top left, rgba(244,114,182,0.08), transparent 60%); }
.hero-card:nth-child(4)::before { background: radial-gradient(circle at top left, rgba(251,191,36,0.08), transparent 60%); }

.hero-card:hover {
  transform: translateY(-4px);
  border-color: rgba(255,255,255,0.12);
}

.hero-card:hover::before { opacity: 1; }

.card-icon {
  font-size: 2rem;
  margin-bottom: 1rem;
}

.hero-card h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}

.hero-card p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.5;
  margin: 0;
}

.card-arrow {
  position: absolute;
  top: 1.5rem;
  right: 1.5rem;
  color: var(--text-muted);
  font-size: 1.2rem;
  transition: var(--transition);
}

.hero-card:hover .card-arrow {
  color: var(--accent-cyan);
  transform: translate(2px, -2px);
}

/* ===== MODE BUTTONS (pathfinding) ===== */
.mode-btn {
  padding: 7px 14px;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: var(--bg-elevated);
  color: var(--text-secondary);
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.75rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
}

.mode-btn.active {
  border-color: var(--accent-cyan);
  background: rgba(0,245,212,0.1);
  color: var(--accent-cyan);
}

.mode-btn:hover { color: var(--accent-cyan); }

/* ===== GRAPH CONTROLS ===== */
.graph-wrapper {
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: 1.5rem;
  align-items: start;
}

.graph-sidebar {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
}

.graph-sidebar h3 {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 1rem;
  font-family: 'JetBrains Mono', monospace;
}

.traversal-log {
  background: var(--bg-secondary);
  border-radius: 8px;
  padding: 1rem;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.75rem;
  color: var(--text-secondary);
  min-height: 120px;
  max-height: 200px;
  overflow-y: auto;
  line-height: 1.8;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
  .navbar { padding: 0 1rem; }
  .nav-links { gap: 2px; }
  .nav-links a { padding: 6px 10px; font-size: 0.8rem; }
  .container { padding: 0 1rem; }
  .control-panel { flex-direction: column; align-items: flex-start; }
  .graph-wrapper { grid-template-columns: 1fr; }
  .hero h1 { letter-spacing: -2px; }
}

/* ===== ANIMATIONS ===== */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

.fade-in { animation: fadeIn 0.4s ease forwards; }

.running-pulse {
  animation: pulse 1.5s ease-in-out infinite;
}
.algo-explanation{
  margin-top:2rem;
  padding:1.5rem;
  background:#111125;
  border-radius:10px;
  line-height:1.6;
}

.algo-explanation h2{
  color:#00eaff;
  margin-bottom:10px;
}

.algo-explanation h3{
  margin-top:1rem;
  color:#a78bfa;
}

.algo-explanation pre{
  background:#0b0b18;
  padding:10px;
  border-radius:6px;
  overflow:auto;
}