/* ============================================================
   Cache Memory Simulator — Dark Lab Design System
   Aesthetic: Scientific Precision × Dark Lab
   Font: IBM Plex Mono + IBM Plex Sans
   Color: Deep navy + electric cyan + amber accent
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Mono:wght@400;600;700&family=IBM+Plex+Sans:ital,wght@0,300;0,400;0,600;0,700;1,400&display=swap');

/* ── CSS Variables ── */
:root {
  --bg:          #0a0e1a;
  --bg-2:        #0f1526;
  --panel:       #131929;
  --panel-2:     #1a2238;
  --border:      #1e2d4a;
  --border-2:    #253352;

  --cyan:        #00d4ff;
  --cyan-dim:    #00a8cc;
  --cyan-glow:   rgba(0, 212, 255, 0.15);
  --amber:       #ffb347;
  --amber-dim:   #cc8a2a;
  --green:       #39d98a;
  --red:         #ff5a5f;
  --purple:      #a78bfa;

  --text-primary:   #e8f0fe;
  --text-secondary: #8899bb;
  --text-muted:     #4a5f80;
  --text-code:      #7dd3fc;

  --font-mono: 'IBM Plex Mono', 'Courier New', monospace;
  --font-sans: 'IBM Plex Sans', 'Segoe UI', sans-serif;

  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 14px;

  --shadow-panel: 0 4px 24px rgba(0,0,0,0.6), 0 1px 0 rgba(255,255,255,0.03) inset;
  --shadow-glow:  0 0 20px rgba(0, 212, 255, 0.12);
  --transition: 0.18s cubic-bezier(0.4, 0, 0.2, 1);

  /* Legacy aliases for JS compatibility */
  --hit-color:          var(--green);
  --miss-color:         var(--red);
  --evict-color:        var(--amber);
  --highlight-mem-bg:   var(--amber);
  --highlight-mem-text: var(--bg);
}

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

html { scroll-behavior: smooth; font-size: 15px; }

body {
  font-family: var(--font-sans);
  background-color: var(--bg);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  position: relative;
  overflow-x: hidden;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 72px 20px 60px;
}

/* Grid background texture */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(rgba(0,212,255,0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0,212,255,0.025) 1px, transparent 1px);
  background-size: 40px 40px;
  pointer-events: none;
  z-index: 0;
}

/* Radial glow at top */
body::after {
  content: '';
  position: fixed;
  top: -200px;
  left: 50%;
  transform: translateX(-50%);
  width: 800px;
  height: 400px;
  background: radial-gradient(ellipse, rgba(0,212,255,0.06) 0%, transparent 70%);
  pointer-events: none;
  z-index: 0;
}

/* ── HOME BUTTON ── */
.home-btn {
  position: fixed;
  top: 16px;
  left: 16px;
  z-index: 9999;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 18px 9px 12px;
  background: var(--panel);
  color: var(--cyan);
  text-decoration: none;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-2);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  transition: all var(--transition);
  box-shadow: var(--shadow-panel);
  backdrop-filter: blur(8px);
}

.home-btn svg {
  width: 16px;
  height: 16px;
  stroke: var(--cyan);
  transition: transform var(--transition);
  flex-shrink: 0;
}

.home-btn:hover {
  background: var(--cyan);
  color: var(--bg);
  border-color: var(--cyan);
  box-shadow: var(--shadow-panel), 0 0 20px rgba(0,212,255,0.4);
  transform: translateY(-1px);
}

.home-btn:hover svg { stroke: var(--bg); transform: scale(1.1); }
.home-btn:active { transform: translateY(0); }

/* ── PAGE HEADER ── */
.page-header {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: 1120px;
  margin-bottom: 24px;
  animation: fadeInUp 0.4s ease both;
}

.topic-tag {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  background: var(--cyan-glow);
  border: 1px solid rgba(0,212,255,0.25);
  border-radius: 999px;
  padding: 3px 10px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 600;
  color: var(--cyan);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 8px;
}

h1 {
  font-family: var(--font-mono);
  font-size: clamp(1.3rem, 3vw, 1.9rem);
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.02em;
  margin-bottom: 6px;
}

h1 .accent { color: var(--cyan); }

.page-subtitle {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--text-secondary);
  letter-spacing: 0.03em;
}

/* ── STATS PANEL ── */
.stats-panel {
  position: relative;
  z-index: 1;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 20px;
  width: 100%;
  max-width: 1120px;
  animation: fadeInUp 0.4s ease 0.05s both;
}

.stat-card {
  flex: 1;
  min-width: 130px;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 14px 18px;
  box-shadow: var(--shadow-panel);
  display: flex;
  flex-direction: column;
  gap: 4px;
  transition: border-color var(--transition);
}

.stat-card:hover { border-color: var(--border-2); }

.stat-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--cyan-dim), transparent);
  opacity: 0.3;
  border-radius: var(--radius-md) var(--radius-md) 0 0;
}

.stat-label {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

.stat-value {
  font-family: var(--font-mono);
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1;
}

.stat-card.cyan  .stat-value { color: var(--cyan); }
.stat-card.green .stat-value { color: var(--green); }
.stat-card.red   .stat-value { color: var(--red); }
.stat-card.amber .stat-value { color: var(--amber); }

/* ── CONTROLS ── */
.controls {
  position: relative;
  z-index: 1;
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  align-items: flex-end;
  background: var(--panel);
  border: 1px solid var(--border);
  padding: 18px 20px;
  border-radius: var(--radius-lg);
  margin-bottom: 20px;
  width: 100%;
  max-width: 1120px;
  box-shadow: var(--shadow-panel);
  animation: fadeInUp 0.4s ease 0.1s both;
}

.controls::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--cyan-dim), transparent);
  opacity: 0.4;
  border-radius: var(--radius-lg) var(--radius-lg) 0 0;
}

.control-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

input[type="text"],
select {
  padding: 9px 12px;
  font-size: 0.85rem;
  border: 1px solid var(--border-2);
  border-radius: var(--radius-sm);
  background: var(--bg-2);
  color: var(--text-primary);
  font-family: var(--font-mono);
  transition: border-color var(--transition), box-shadow var(--transition);
  appearance: none;
  -webkit-appearance: none;
}

input[type="text"] { width: 260px; }

input[type="text"]:focus,
select:focus {
  outline: none;
  border-color: var(--cyan);
  box-shadow: 0 0 0 3px rgba(0,212,255,0.12);
}

select {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' fill='none' stroke='%2300d4ff' stroke-width='2'%3E%3Cpath d='M1 1l5 5 5-5'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  padding-right: 36px;
  cursor: pointer;
  min-width: 180px;
}

select option { background: var(--panel); color: var(--text-primary); }

button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 9px 20px;
  background: var(--panel-2);
  color: var(--cyan);
  border: 1px solid var(--border-2);
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  cursor: pointer;
  transition: all var(--transition);
  white-space: nowrap;
  height: 40px;
}

button:hover {
  background: var(--cyan);
  color: var(--bg);
  border-color: var(--cyan);
  box-shadow: 0 0 14px rgba(0,212,255,0.35);
  transform: translateY(-1px);
}

button:active { transform: translateY(0); box-shadow: none; }

button.danger { color: var(--red); border-color: rgba(255,90,95,0.4); }
button.danger:hover {
  background: var(--red);
  color: var(--bg);
  border-color: var(--red);
  box-shadow: 0 0 14px rgba(255,90,95,0.35);
}

/* ── DASHBOARD ── */
.dashboard {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 340px 1fr;
  gap: 20px;
  max-width: 1120px;
  width: 100%;
  animation: fadeInUp 0.4s ease 0.15s both;
}

/* ── PANELS ── */
.panel {
  position: relative;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 20px;
  box-shadow: var(--shadow-panel);
  overflow: hidden;
}

.panel::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--cyan-dim), transparent);
  opacity: 0.4;
}

.panel h3 {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--cyan);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.panel h3::before {
  content: '';
  display: inline-block;
  width: 6px;
  height: 6px;
  background: var(--cyan);
  border-radius: 50%;
  box-shadow: 0 0 6px var(--cyan);
}

/* ── MAIN MEMORY GRID ── */
.grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
  margin-top: 4px;
}

.block {
  background: var(--bg-2);
  border: 1px solid var(--border);
  padding: 9px 6px;
  text-align: center;
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--text-secondary);
  transition: all 0.3s ease;
  cursor: default;
  position: relative;
}

.block.highlight-mem {
  background: var(--amber) !important;
  color: var(--bg) !important;
  border-color: var(--amber) !important;
  box-shadow: 0 0 12px rgba(255,179,71,0.5) !important;
  transform: scale(1.06);
  color: var(--bg);
  font-weight: 700;
}

/* ── ADDRESS BREAKDOWN ── */
.address-breakdown {
  background: var(--bg);
  border: 1px solid var(--border-2);
  padding: 12px 16px;
  border-radius: var(--radius-md);
  margin-bottom: 16px;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--text-secondary);
  text-align: center;
  min-height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  line-height: 1.5;
}

.address-breakdown strong { color: var(--cyan); font-weight: 700; }

/* ── CACHE TABLE ── */
.cache-table {
  width: 100%;
  border-collapse: collapse;
  font-family: var(--font-mono);
  font-size: 0.82rem;
}

.cache-table th {
  background: var(--bg);
  border: 1px solid var(--border);
  padding: 10px 12px;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.cache-table td {
  border: 1px solid var(--border);
  padding: 10px 12px;
  text-align: center;
  color: var(--text-secondary);
  transition: all 0.35s ease;
  font-size: 0.82rem;
}

.cache-table tr { transition: background 0.35s ease; }

.cache-table tr:hover td { background: rgba(255,255,255,0.02); }

.set-divider { border-bottom: 2px solid var(--cyan) !important; }
.set-divider td { border-bottom: 2px solid var(--cyan) !important; }

/* Hit — glowing green */
.highlight-hit td {
  background: rgba(57,217,138,0.12) !important;
  color: var(--green) !important;
}
.highlight-hit td:first-child {
  border-left: 3px solid var(--green) !important;
}

/* Evicted — amber warning */
.highlight-evict td {
  background: rgba(255,179,71,0.12) !important;
  color: var(--amber) !important;
}
.highlight-evict td:first-child {
  border-left: 3px solid var(--amber) !important;
}

/* ── LOG PANEL ── */
.log-panel {
  margin-top: 18px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.log-panel h4 {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 700;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  padding: 10px 14px;
  background: var(--panel-2);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: 6px;
}

.log-panel h4::before {
  content: '›';
  color: var(--cyan);
  font-size: 0.9rem;
}

#logArea {
  height: 160px;
  overflow-y: auto;
  padding: 6px 0;
}

#logArea::-webkit-scrollbar { width: 4px; }
#logArea::-webkit-scrollbar-track { background: var(--bg); }
#logArea::-webkit-scrollbar-thumb { background: var(--border-2); border-radius: 999px; }

.log-item {
  padding: 7px 14px;
  border-bottom: 1px solid rgba(30,45,74,0.6);
  font-family: var(--font-mono);
  font-size: 0.76rem;
  color: var(--text-secondary);
  line-height: 1.5;
  transition: background var(--transition);
}

.log-item:first-child {
  background: rgba(0,212,255,0.04);
}

.log-item:last-child { border-bottom: none; }

.hit-text  { color: var(--green); font-weight: 700; }
.miss-text { color: var(--red);   font-weight: 700; }

/* ── EDUCATIONAL BAR ── */
.edu-bar {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: 1120px;
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  margin-top: 28px;
  overflow: hidden;
  animation: fadeInUp 0.4s ease 0.2s both;
}

.edu-bar-header {
  padding: 12px 20px;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--cyan);
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

.edu-bar-header svg { stroke: var(--cyan); }

.edu-facts {
  display: flex;
  flex-wrap: wrap;
  gap: 0;
  padding: 0;
}

.edu-fact-item {
  flex: 1;
  min-width: 200px;
  padding: 14px 18px;
  border-right: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  transition: background var(--transition);
}

.edu-fact-item:hover { background: rgba(0,212,255,0.03); }
.edu-fact-item:last-child { border-right: none; }

.edu-fact-label {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  font-weight: 700;
  color: var(--amber);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 4px;
}

.edu-fact-text {
  display: block;
  font-size: 0.82rem;
  color: var(--text-secondary);
  line-height: 1.5;
  font-family: var(--font-mono);
}

/* ── ANIMATIONS ── */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(16px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ── RESPONSIVE ── */
@media (max-width: 900px) {
  .dashboard {
    grid-template-columns: 1fr;
  }

  body { padding: 68px 14px 40px; }

  .home-btn {
    top: 10px;
    left: 10px;
    padding: 7px 14px 7px 10px;
    font-size: 0.74rem;
  }

  input[type="text"] { width: 100%; }

  .controls { flex-direction: column; }

  button { width: 100%; }
}

@media (max-width: 600px) {
  html { font-size: 14px; }

  .stats-panel { flex-direction: column; }

  .stat-card { min-width: 0; }

  .grid { grid-template-columns: repeat(4, 1fr); gap: 5px; }

  .edu-fact-item { min-width: 100%; border-right: none; }
}

/* ── ACCESSIBILITY ── */
:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

/* ── SCROLLBAR ── */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--border-2); border-radius: 999px; }
::-webkit-scrollbar-thumb:hover { background: var(--cyan-dim); }

/* ── SCROLL & RESPONSIVE FIX ── */
body {
  padding-top: 72px !important;
  overflow-x: hidden !important;
  overflow-y: auto !important;
  height: auto !important;
}
@media (max-width: 900px) {
  .main-grid, .sim-grid {
    grid-template-columns: 1fr !important;
  }
}