/* ═══════════════════════════════════════════════════════════════════════════
   NetLab — Network+ Learning Game  |  styles.css
   Dark theme (default), UniFi/Meraki-inspired professional UI
   ═══════════════════════════════════════════════════════════════════════════ */

/* ─── CSS Variables ──────────────────────────────────────────────────────── */
:root {
  --bg-0:       #0a0e1a;
  --bg-1:       #111827;
  --bg-2:       #1e2535;
  --bg-3:       #252d3d;
  --bg-4:       #2d3748;
  --border:     #374151;
  --border-dim: #1f2937;

  --text-primary:   #e2e8f0;
  --text-secondary: #94a3b8;
  --text-muted:     #4b5563;
  --text-on-accent: #ffffff;

  --accent:    #4cc9f0;
  --accent-dk: #3aa8ce;
  --success:   #10b981;
  --warning:   #f59e0b;
  --error:     #ef4444;
  --info:      #6366f1;

  --led-up:   #22c55e;
  --led-err:  #f97316;
  --led-off:  #1f2937;
  --led-glow: rgba(34,197,94,.5);

  --font-ui:   'Inter', system-ui, sans-serif;
  --font-mono: 'Fira Code', 'Consolas', 'Courier New', monospace;

  --radius-sm: 4px;
  --radius:    8px;
  --radius-lg: 12px;

  --shadow:    0 2px 8px rgba(0,0,0,.5);
  --shadow-lg: 0 8px 24px rgba(0,0,0,.6);

  /* VLAN colours */
  --vlan-1:  #6b7280;
  --vlan-10: #4cc9f0;
  --vlan-20: #10b981;
  --vlan-30: #f59e0b;
  --vlan-40: #ef4444;
  --vlan-50: #8b5cf6;
  --vlan-60: #ec4899;
  --vlan-70: #06b6d4;
  --vlan-80: #84cc16;

  --nav-h:     56px;
  --sidebar-w: 220px;
  --right-w:   280px;
  --cli-h:     200px;
}

.light-theme {
  --bg-0:       #f0f4f8;
  --bg-1:       #ffffff;
  --bg-2:       #f8fafc;
  --bg-3:       #e2e8f0;
  --bg-4:       #cbd5e1;
  --border:     #d1d5db;
  --border-dim: #e5e7eb;
  --text-primary:   #1e293b;
  --text-secondary: #475569;
  --text-muted:     #94a3b8;
  --led-off:  #d1d5db;
}

/* ─── Reset ──────────────────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 14px; scroll-behavior: smooth; }
body {
  font-family: var(--font-ui);
  background: var(--bg-0);
  color: var(--text-primary);
  line-height: 1.5;
  height: 100vh;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

/* ─── Navigation ─────────────────────────────────────────────────────────── */
#main-nav {
  height: var(--nav-h);
  background: var(--bg-2);
  border-bottom: 1px solid var(--border-dim);
  display: flex;
  align-items: center;
  padding: 0 1rem;
  gap: 1.5rem;
  flex-shrink: 0;
  z-index: 100;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: .5rem;
  flex-shrink: 0;
}
.brand-icon { font-size: 1.4rem; color: var(--accent); }
.brand-name { font-size: 1.1rem; font-weight: 700; color: var(--text-primary); }
.brand-tag {
  font-size: .65rem;
  font-weight: 600;
  background: var(--accent);
  color: #000;
  padding: 2px 6px;
  border-radius: 20px;
  letter-spacing: .04em;
  text-transform: uppercase;
}

.nav-modes {
  display: flex;
  gap: .25rem;
  flex: 1;
}

.mode-btn {
  background: transparent;
  border: 1px solid transparent;
  color: var(--text-secondary);
  padding: .4rem .8rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-family: var(--font-ui);
  font-size: .85rem;
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: .35rem;
  transition: all .15s ease;
}
.mode-btn:hover { background: var(--bg-3); color: var(--text-primary); }
.mode-btn.active {
  background: var(--bg-4);
  border-color: var(--border);
  color: var(--accent);
}
.mode-icon { font-size: .9rem; }

.nav-progress {
  display: flex;
  align-items: center;
  gap: .75rem;
  flex-shrink: 0;
}
.xp-display { display: flex; align-items: center; gap: .5rem; }
.level-badge {
  background: linear-gradient(135deg, var(--accent), var(--info));
  color: #fff;
  font-size: .7rem;
  font-weight: 700;
  padding: 3px 8px;
  border-radius: 20px;
  white-space: nowrap;
}
.xp-bar-wrap {
  width: 80px;
  height: 6px;
  background: var(--bg-4);
  border-radius: 3px;
  overflow: hidden;
}
.xp-bar {
  height: 100%;
  background: linear-gradient(90deg, var(--accent), var(--success));
  width: 0%;
  transition: width .4s ease;
  border-radius: 3px;
}
.xp-text { font-size: .75rem; color: var(--text-secondary); white-space: nowrap; }

.icon-btn {
  background: var(--bg-3);
  border: 1px solid var(--border-dim);
  color: var(--text-secondary);
  width: 32px; height: 32px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: .9rem;
  display: flex; align-items: center; justify-content: center;
  transition: all .15s;
}
.icon-btn:hover { background: var(--bg-4); color: var(--text-primary); }

/* ─── Main layout ────────────────────────────────────────────────────────── */
#app-wrapper {
  display: flex;
  flex: 1;
  overflow: hidden;
  height: calc(100vh - var(--nav-h));
}

/* ─── Left Sidebar ───────────────────────────────────────────────────────── */
#left-panel {
  width: var(--sidebar-w);
  background: var(--bg-1);
  border-right: 1px solid var(--border-dim);
  overflow-y: auto;
  flex-shrink: 0;
  padding: .75rem;
}
.sidebar-title {
  font-size: .75rem;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: var(--text-muted);
  padding: .25rem .25rem .75rem;
}
.sidebar-content { display: none; }
.sidebar-content.active { display: block; }

/* Lesson list */
.lesson-list { display: flex; flex-direction: column; gap: .25rem; }
.lesson-item {
  padding: .5rem .65rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: .5rem;
  transition: background .1s;
  border: 1px solid transparent;
}
.lesson-item:hover { background: var(--bg-2); }
.lesson-item.active { background: var(--bg-3); border-color: var(--border); }
.lesson-item.completed .lesson-status { color: var(--success); }
.lesson-num { font-size: .7rem; color: var(--text-muted); min-width: 1.4rem; }
.lesson-name { font-size: .82rem; flex: 1; }
.lesson-status { font-size: .75rem; color: var(--text-muted); }

/* Challenge list */
.challenge-list { display: flex; flex-direction: column; gap: .4rem; }
.challenge-item {
  padding: .6rem .65rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  border: 1px solid var(--border-dim);
  background: var(--bg-2);
  transition: all .15s;
}
.challenge-item:hover { border-color: var(--border); background: var(--bg-3); }
.challenge-item.active { border-color: var(--accent); }
.challenge-title { font-size: .82rem; font-weight: 500; margin-bottom: .2rem; }
.challenge-meta { display: flex; gap: .5rem; align-items: center; }
.difficulty-badge {
  font-size: .65rem;
  padding: 2px 6px;
  border-radius: 10px;
  font-weight: 600;
}
.diff-easy { background: rgba(16,185,129,.2); color: var(--success); }
.diff-medium { background: rgba(245,158,11,.2); color: var(--warning); }
.diff-hard { background: rgba(239,68,68,.2); color: var(--error); }
.challenge-xp { font-size: .7rem; color: var(--accent); }

/* Quiz categories */
.quiz-categories { display: flex; flex-direction: column; gap: .4rem; }
.quiz-cat-item {
  padding: .55rem .65rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  background: var(--bg-2);
  border: 1px solid var(--border-dim);
  transition: all .15s;
}
.quiz-cat-item:hover { border-color: var(--border); background: var(--bg-3); }
.quiz-cat-item.active { border-color: var(--accent); }
.quiz-cat-name { font-size: .82rem; font-weight: 500; }
.quiz-cat-count { font-size: .7rem; color: var(--text-muted); }

/* Sandbox tools */
.sandbox-tools { display: flex; flex-direction: column; gap: .35rem; margin-bottom: 1rem; }
.sandbox-info h3 { font-size: .75rem; text-transform: uppercase; letter-spacing: .08em; color: var(--text-muted); margin-bottom: .5rem; }

/* ─── Centre Panel ───────────────────────────────────────────────────────── */
#centre-panel {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  background: var(--bg-0);
  min-width: 0;
}

#mode-header {
  background: var(--bg-2);
  border-bottom: 1px solid var(--border-dim);
  padding: .5rem 1rem;
  display: flex;
  align-items: center;
  gap: 1rem;
  min-height: 40px;
  flex-shrink: 0;
}
#mode-objective { font-size: .85rem; color: var(--text-secondary); flex: 1; }
#mode-controls { display: flex; gap: .5rem; }

/* ─── Tutorial / Quiz content panes ─────────────────────────────────────── */
.content-pane {
  background: var(--bg-1);
  border-bottom: 1px solid var(--border-dim);
  padding: 1rem 1.25rem;
  overflow-y: auto;
  max-height: 260px;
  flex-shrink: 0;
}
.content-pane.hidden { display: none; }

#lesson-body h1 { font-size: 1.1rem; color: var(--accent); margin-bottom: .5rem; }
#lesson-body h2 { font-size: .95rem; color: var(--text-primary); margin: .75rem 0 .3rem; }
#lesson-body p { font-size: .85rem; color: var(--text-secondary); margin-bottom: .5rem; line-height: 1.6; }
#lesson-body ul, #lesson-body ol { padding-left: 1.25rem; margin-bottom: .5rem; }
#lesson-body li { font-size: .85rem; color: var(--text-secondary); margin-bottom: .2rem; }
#lesson-body code {
  font-family: var(--font-mono);
  background: var(--bg-3);
  padding: 2px 5px;
  border-radius: 3px;
  font-size: .8rem;
  color: var(--accent);
}
#lesson-body pre {
  background: var(--bg-0);
  padding: .75rem 1rem;
  border-radius: var(--radius-sm);
  overflow-x: auto;
  margin: .5rem 0;
}
#lesson-body pre code { background: transparent; padding: 0; }
.task-box {
  background: rgba(76,201,240,.08);
  border: 1px solid rgba(76,201,240,.25);
  border-radius: var(--radius-sm);
  padding: .75rem 1rem;
  margin: .75rem 0;
}
.task-box h3 { font-size: .82rem; font-weight: 600; color: var(--accent); margin-bottom: .3rem; }
.task-box p { color: var(--text-secondary); font-size: .82rem; }

.lesson-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: .75rem;
  padding-top: .5rem;
  border-top: 1px solid var(--border-dim);
}
#step-indicator { font-size: .75rem; color: var(--text-muted); }
.nav-btn {
  background: var(--bg-3);
  border: 1px solid var(--border);
  color: var(--text-primary);
  padding: .35rem .8rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: .8rem;
  transition: all .15s;
}
.nav-btn:hover { background: var(--bg-4); }
.nav-btn.primary { background: var(--accent); border-color: var(--accent); color: #000; font-weight: 600; }
.nav-btn.primary:hover { background: var(--accent-dk); }
.nav-btn:disabled { opacity: .4; cursor: not-allowed; }

/* ─── Switch Area ────────────────────────────────────────────────────────── */
#switch-area {
  padding: .75rem 1rem;
  display: flex;
  flex-direction: column;
  gap: .75rem;
  overflow-y: auto;
  flex: 1;
}

#switch-chassis {
  background: linear-gradient(180deg, #2a2a2a 0%, #1a1a1a 100%);
  border: 1px solid #444;
  border-radius: var(--radius);
  padding: .5rem .75rem;
  box-shadow: var(--shadow-lg), inset 0 1px 0 rgba(255,255,255,.06);
  flex-shrink: 0;
}

.switch-brand-bar {
  display: flex;
  align-items: center;
  gap: .5rem;
  margin-bottom: .4rem;
  padding-bottom: .3rem;
  border-bottom: 1px solid #333;
}
.switch-brand { font-size: .7rem; font-weight: 700; color: #888; letter-spacing: .1em; text-transform: uppercase; }
.switch-model { font-size: .65rem; color: #555; margin-left: auto; }
.switch-power-led {
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--led-up);
  box-shadow: 0 0 6px var(--led-glow);
  animation: pulseLed 2s ease-in-out infinite;
}

.switch-ports-wrap {
  display: flex;
  align-items: flex-start;
  gap: .5rem;
}
.port-grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  grid-template-rows: repeat(2, auto);
  gap: 4px;
  flex: 1;
}

/* Each port cell */
.sw-port {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  cursor: pointer;
  padding: 4px 3px;
  border-radius: 4px;
  border: 1px solid transparent;
  transition: all .12s ease;
  position: relative;
}
.sw-port:hover { background: rgba(255,255,255,.06); border-color: #555; }
.sw-port.selected { background: rgba(76,201,240,.12); border-color: var(--accent) !important; }
.sw-port.port-down { opacity: .5; }
.sw-port.port-violation { animation: blink .5s step-end infinite; }

.port-led {
  width: 5px; height: 5px;
  border-radius: 50%;
  background: var(--led-off);
  transition: background .3s, box-shadow .3s;
}
.port-led.led-up       { background: var(--led-up);  box-shadow: 0 0 5px var(--led-glow); }
.port-led.led-inactive { background: #374151; }
.port-led.led-down     { background: #1f2937; }
.port-led.led-err      { background: var(--led-err);  box-shadow: 0 0 5px rgba(249,115,22,.5); }
.port-led.led-blink    { animation: blinkLed .6s step-end infinite; }

.port-jack {
  width: 20px; height: 14px;
  background: #0a0a0a;
  border: 1.5px solid #555;
  border-radius: 2px;
  position: relative;
  transition: border-color .12s;
}
.sw-port:hover .port-jack { border-color: #888; }
.port-jack.connected { border-color: var(--led-up); }
.port-jack.connected::after {
  content: '';
  position: absolute;
  left: 50%; top: 50%;
  transform: translate(-50%,-50%);
  width: 8px; height: 5px;
  background: var(--led-up);
  border-radius: 1px;
  opacity: .7;
}

.port-label { font-size: 8px; color: #666; font-family: var(--font-mono); white-space: nowrap; }
.sw-port.selected .port-label { color: var(--accent); }
.port-badges { display: flex; gap: 1px; justify-content: center; min-height: 10px; }
.port-vlan-dot {
  width: 4px; height: 4px;
  border-radius: 50%;
  background: transparent;
}

/* VLAN-coloured dots on ports */
.vlan-color-1  { background: var(--vlan-1);  }
.vlan-color-10 { background: var(--vlan-10); }
.vlan-color-20 { background: var(--vlan-20); }
.vlan-color-30 { background: var(--vlan-30); }
.vlan-color-40 { background: var(--vlan-40); }
.vlan-color-50 { background: var(--vlan-50); }
.vlan-color-60 { background: var(--vlan-60); }
.vlan-color-70 { background: var(--vlan-70); }
.vlan-color-80 { background: var(--vlan-80); }

.sfp-section {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 3px;
}
.sfp-label { font-size: 8px; color: #555; text-transform: uppercase; }
.sfp-ports { display: flex; flex-direction: column; gap: 4px; }
.sfp-port {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  cursor: pointer;
  padding: 3px;
  border-radius: 3px;
  border: 1px solid transparent;
  transition: all .12s;
}
.sfp-port:hover { background: rgba(255,255,255,.06); border-color: #555; }
.sfp-jack {
  width: 22px; height: 10px;
  background: #060606;
  border: 1.5px solid #444;
  border-radius: 1px;
}

.switch-bottom-bar {
  display: flex;
  align-items: center;
  gap: .5rem;
  margin-top: .35rem;
  padding-top: .3rem;
  border-top: 1px solid #333;
}
.console-label, .mgmt-label { font-size: 7px; color: #555; text-transform: uppercase; }
.console-port, .mgmt-port {
  width: 14px; height: 10px;
  border: 1px solid #444;
  border-radius: 1px;
  background: #0a0a0a;
}

/* ─── Topology ───────────────────────────────────────────────────────────── */
#topology-container {
  background: var(--bg-1);
  border: 1px solid var(--border-dim);
  border-radius: var(--radius);
  overflow: hidden;
  flex-shrink: 0;
}
.topology-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: .4rem .75rem;
  background: var(--bg-2);
  border-bottom: 1px solid var(--border-dim);
  font-size: .78rem;
  font-weight: 600;
  color: var(--text-secondary);
}
.topology-controls { display: flex; gap: .35rem; }
.topo-btn {
  background: var(--bg-3);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  padding: 2px 8px;
  border-radius: 3px;
  cursor: pointer;
  font-size: .72rem;
  transition: all .12s;
}
.topo-btn:hover { background: var(--bg-4); color: var(--text-primary); }

#topology-svg { display: block; }

/* Topology SVG element styles */
.topo-device-group { cursor: pointer; }
.topo-device-body { transition: filter .2s; }
.topo-device-group:hover .topo-device-body { filter: brightness(1.3); }
.topo-link { stroke-width: 2; fill: none; opacity: .8; }
.topo-label { font-family: var(--font-ui); font-size: 10px; fill: var(--text-secondary); text-anchor: middle; }
.topo-ip-label { font-family: var(--font-mono); font-size: 9px; fill: var(--text-muted); text-anchor: middle; }
.topo-packet { r: 4; opacity: .9; }

/* ─── CLI Terminal ───────────────────────────────────────────────────────── */
#cli-panel {
  background: #0a0c10;
  border-top: 1px solid #1f2937;
  height: var(--cli-h);
  display: flex;
  flex-direction: column;
  flex-shrink: 0;
  font-family: var(--font-mono);
}
.cli-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: .25rem .75rem;
  background: #111218;
  border-bottom: 1px solid #1f2937;
  flex-shrink: 0;
}
.cli-title { font-size: .7rem; color: #4b5563; text-transform: uppercase; letter-spacing: .08em; }
.cli-header-controls { display: flex; gap: .3rem; }
.cli-btn {
  background: transparent;
  border: 1px solid #1f2937;
  color: #4b5563;
  padding: 2px 8px;
  border-radius: 3px;
  cursor: pointer;
  font-size: .7rem;
  font-family: var(--font-mono);
  transition: all .12s;
}
.cli-btn:hover { border-color: #374151; color: var(--text-secondary); }

.cli-output {
  flex: 1;
  overflow-y: auto;
  padding: .4rem .75rem;
  font-size: .78rem;
  line-height: 1.55;
  color: #c9d1d9;
}
.cli-output::-webkit-scrollbar { width: 4px; }
.cli-output::-webkit-scrollbar-thumb { background: #2d3748; border-radius: 2px; }

.cli-line { margin: 0; white-space: pre-wrap; word-break: break-all; }
.cli-cmd  { color: #4cc9f0; }
.cli-ok   { color: #10b981; }
.cli-warn { color: #f59e0b; }
.cli-err  { color: #ef4444; }
.cli-info { color: #6366f1; }
.cli-table { color: #c9d1d9; }
.cli-sep  { color: #374151; }

.cli-input-row {
  display: flex;
  align-items: center;
  padding: .3rem .75rem;
  border-top: 1px solid #1a1f2b;
  background: #0a0c10;
  flex-shrink: 0;
}
.cli-prompt { color: #4cc9f0; font-size: .8rem; white-space: nowrap; }
.cli-input {
  flex: 1;
  background: transparent;
  border: none;
  outline: none;
  color: #e2e8f0;
  font-family: var(--font-mono);
  font-size: .8rem;
  padding: 0;
  caret-color: var(--accent);
}

/* ─── Right Panel / Config Panel ─────────────────────────────────────────── */
#right-panel {
  width: var(--right-w);
  background: var(--bg-1);
  border-left: 1px solid var(--border-dim);
  overflow-y: auto;
  flex-shrink: 0;
}

#switch-info-panel {
  padding: .75rem;
}
#switch-info-panel h3 {
  font-size: .75rem;
  text-transform: uppercase;
  letter-spacing: .06em;
  color: var(--text-muted);
  margin-bottom: .5rem;
}
#switch-stats { font-size: .8rem; color: var(--text-secondary); }
.stat-row { display: flex; justify-content: space-between; padding: .2rem 0; border-bottom: 1px solid var(--border-dim); }
.stat-label { color: var(--text-muted); }
.stat-value { color: var(--accent); font-family: var(--font-mono); }

#vlan-database-display { display: flex; flex-direction: column; gap: 2px; }
.vlan-row {
  display: flex;
  align-items: center;
  gap: .4rem;
  padding: .2rem .3rem;
  border-radius: 3px;
  font-size: .78rem;
}
.vlan-row:hover { background: var(--bg-2); }
.vlan-dot { width: 8px; height: 8px; border-radius: 50%; flex-shrink: 0; }
.vlan-id { font-family: var(--font-mono); color: var(--text-secondary); min-width: 2rem; }
.vlan-name-label { color: var(--text-primary); flex: 1; }
.vlan-port-count { font-size: .7rem; color: var(--text-muted); }

.config-panel { padding: .75rem; }
.config-panel.hidden { display: none; }
.config-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: .75rem;
  padding-bottom: .5rem;
  border-bottom: 1px solid var(--border-dim);
}
.config-header h3 { font-size: .9rem; color: var(--accent); }

.config-section { margin-bottom: .75rem; }
.config-section > label {
  display: block;
  font-size: .72rem;
  text-transform: uppercase;
  letter-spacing: .06em;
  color: var(--text-muted);
  margin-bottom: .3rem;
}
.toggle-group { display: flex; gap: 2px; }
.toggle-btn {
  background: var(--bg-2);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  padding: .3rem .65rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: .78rem;
  transition: all .12s;
  flex: 1;
  text-align: center;
}
.toggle-btn.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #000;
  font-weight: 600;
}
.toggle-btn:hover:not(.active) { background: var(--bg-3); }

.cfg-input {
  width: 100%;
  background: var(--bg-0);
  border: 1px solid var(--border);
  color: var(--text-primary);
  padding: .35rem .5rem;
  border-radius: var(--radius-sm);
  font-family: var(--font-ui);
  font-size: .82rem;
  outline: none;
  transition: border-color .12s;
}
.cfg-input:focus { border-color: var(--accent); }
.cfg-input.small { width: 80px; }
.cfg-select {
  width: 100%;
  background: var(--bg-0);
  border: 1px solid var(--border);
  color: var(--text-primary);
  padding: .35rem .5rem;
  border-radius: var(--radius-sm);
  font-size: .82rem;
  outline: none;
  cursor: pointer;
}
.cfg-hint { font-size: .68rem; color: var(--text-muted); margin-top: .2rem; display: block; }
.sub-section { margin-top: .4rem; padding-top: .4rem; border-top: 1px solid var(--border-dim); }

.config-actions { display: flex; gap: .4rem; margin-top: 1rem; }
.btn {
  background: var(--bg-3);
  border: 1px solid var(--border);
  color: var(--text-primary);
  padding: .4rem .9rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: .82rem;
  font-family: var(--font-ui);
  transition: all .15s;
}
.btn:hover { background: var(--bg-4); }
.btn.primary { background: var(--accent); border-color: var(--accent); color: #000; font-weight: 600; }
.btn.primary:hover { background: var(--accent-dk); }
.btn.danger { background: var(--error); border-color: var(--error); color: #fff; }
.btn.small { padding: .25rem .6rem; font-size: .75rem; }

.tool-btn {
  background: var(--bg-2);
  border: 1px solid var(--border);
  color: var(--text-primary);
  padding: .4rem .7rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: .8rem;
  width: 100%;
  text-align: left;
  transition: all .12s;
}
.tool-btn:hover { background: var(--bg-3); }
.tool-btn.danger { color: var(--error); }
.tool-btn.small { padding: .25rem .5rem; font-size: .75rem; }

/* ─── Modals ─────────────────────────────────────────────────────────────── */
.modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,.65);
  z-index: 200;
}
.modal-backdrop.hidden { display: none; }

.modal {
  position: fixed;
  top: 50%; left: 50%;
  transform: translate(-50%,-50%);
  z-index: 201;
  min-width: 340px;
}
.modal.hidden { display: none; }

.modal-content {
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
}
.modal-content.wide { min-width: 560px; }

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: .75rem 1rem;
  border-bottom: 1px solid var(--border-dim);
  background: var(--bg-3);
}
.modal-header h3 { font-size: .9rem; }
.modal-body { padding: 1rem; }
.modal-footer {
  display: flex;
  gap: .5rem;
  justify-content: flex-end;
  padding: .75rem 1rem;
  border-top: 1px solid var(--border-dim);
  background: var(--bg-1);
}

.form-field { margin-bottom: .75rem; }
.form-field label {
  display: block;
  font-size: .72rem;
  text-transform: uppercase;
  letter-spacing: .06em;
  color: var(--text-muted);
  margin-bottom: .3rem;
}
.form-field small { color: var(--text-muted); }

/* Achievements grid */
.achievements-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: .75rem;
  max-height: 400px;
  overflow-y: auto;
}
.achievement-card {
  background: var(--bg-3);
  border: 1px solid var(--border-dim);
  border-radius: var(--radius);
  padding: .75rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: .3rem;
  text-align: center;
  transition: all .15s;
}
.achievement-card.unlocked { border-color: var(--warning); background: rgba(245,158,11,.08); }
.achievement-card.locked { filter: grayscale(.8); opacity: .6; }
.achievement-icon { font-size: 1.6rem; }
.achievement-name { font-size: .78rem; font-weight: 600; }
.achievement-desc { font-size: .7rem; color: var(--text-muted); }

/* ─── Toast notifications ────────────────────────────────────────────────── */
.toast-container {
  position: fixed;
  bottom: 1rem;
  right: 1rem;
  z-index: 300;
  display: flex;
  flex-direction: column;
  gap: .4rem;
  pointer-events: none;
}
.toast {
  background: var(--bg-3);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: .6rem 1rem;
  font-size: .82rem;
  box-shadow: var(--shadow-lg);
  max-width: 320px;
  animation: slideInToast .25s ease;
  pointer-events: auto;
  display: flex;
  align-items: center;
  gap: .5rem;
}
.toast.success { border-color: var(--success); background: rgba(16,185,129,.12); }
.toast.error   { border-color: var(--error);   background: rgba(239,68,68,.12); }
.toast.warning { border-color: var(--warning); background: rgba(245,158,11,.12); }
.toast.info    { border-color: var(--info);    background: rgba(99,102,241,.12); }
.toast-icon { font-size: 1rem; }
.toast-text { flex: 1; }
.toast-close { cursor: pointer; color: var(--text-muted); background: none; border: none; font-size: .8rem; padding: 0 2px; }

/* ─── Quiz content ───────────────────────────────────────────────────────── */
#quiz-question-area {
  padding: 1rem;
  max-width: 700px;
}
.question-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: .75rem;
}
.question-progress { font-size: .78rem; color: var(--text-muted); }
.question-category {
  font-size: .7rem;
  background: rgba(99,102,241,.2);
  color: var(--info);
  padding: 2px 8px;
  border-radius: 10px;
}
.question-text { font-size: .95rem; color: var(--text-primary); margin-bottom: 1rem; line-height: 1.5; }
.quiz-options { display: flex; flex-direction: column; gap: .4rem; }
.quiz-option {
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: .65rem .9rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: .6rem;
  transition: all .12s;
  font-size: .85rem;
}
.quiz-option:hover { background: var(--bg-3); border-color: var(--border); }
.quiz-option.correct { border-color: var(--success); background: rgba(16,185,129,.12); color: var(--success); }
.quiz-option.wrong   { border-color: var(--error);   background: rgba(239,68,68,.12); color: var(--error); }
.quiz-option.selected { border-color: var(--accent); }
.option-letter {
  width: 22px; height: 22px;
  border-radius: 50%;
  background: var(--bg-4);
  display: flex; align-items: center; justify-content: center;
  font-size: .75rem;
  font-weight: 600;
  flex-shrink: 0;
}

.quiz-controls { margin-top: 1rem; display: flex; gap: .5rem; align-items: center; }
.quiz-score { font-size: .8rem; color: var(--text-muted); margin-left: auto; }

.quiz-explanation {
  margin-top: .75rem;
  padding: .75rem 1rem;
  background: rgba(99,102,241,.08);
  border: 1px solid rgba(99,102,241,.25);
  border-radius: var(--radius-sm);
  font-size: .82rem;
  color: var(--text-secondary);
  line-height: 1.55;
}
.quiz-explanation strong { color: var(--info); }

/* ─── Challenge mode elements ────────────────────────────────────────────── */
.objective-list { display: flex; flex-direction: column; gap: .3rem; }
.objective-item { display: flex; align-items: center; gap: .4rem; font-size: .8rem; color: var(--text-secondary); }
.objective-item.done { color: var(--success); }
.objective-item .obj-icon { font-size: .85rem; }
.challenge-timer { font-family: var(--font-mono); color: var(--warning); font-size: .85rem; }

/* ─── Animations ─────────────────────────────────────────────────────────── */
@keyframes pulseLed {
  0%, 100% { opacity: 1; box-shadow: 0 0 6px var(--led-glow); }
  50%       { opacity: .7; box-shadow: 0 0 10px var(--led-glow); }
}
@keyframes blink {
  50% { opacity: 0; }
}
@keyframes blinkLed {
  50% { background: var(--led-err); box-shadow: 0 0 5px rgba(249,115,22,.5); }
}
@keyframes slideInToast {
  from { transform: translateX(100%); opacity: 0; }
  to   { transform: translateX(0);    opacity: 1; }
}
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(4px); }
  to   { opacity: 1; transform: translateY(0); }
}
@keyframes packetTravel {
  0%   { opacity: 1; }
  100% { opacity: 0; }
}

/* ─── Scrollbars ─────────────────────────────────────────────────────────── */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--bg-4); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: #4b5563; }

/* ─── Utility classes ────────────────────────────────────────────────────── */
.hidden { display: none !important; }
.fade-in { animation: fadeIn .2s ease; }
.text-accent { color: var(--accent); }
.text-success { color: var(--success); }
.text-error { color: var(--error); }
.text-warn { color: var(--warning); }
.text-muted { color: var(--text-muted); }

/* ─── CLI fullscreen mode ────────────────────────────────────────────────── */
#cli-panel.fullscreen {
  position: fixed;
  inset: 0;
  z-index: 150;
  height: 100vh;
  border: none;
}

/* ─── Tooltip ────────────────────────────────────────────────────────────── */
[data-tooltip] { position: relative; }
[data-tooltip]::after {
  content: attr(data-tooltip);
  position: absolute;
  bottom: calc(100% + 6px);
  left: 50%; transform: translateX(-50%);
  background: var(--bg-4);
  border: 1px solid var(--border);
  color: var(--text-primary);
  font-size: .72rem;
  padding: 4px 8px;
  border-radius: 4px;
  white-space: nowrap;
  pointer-events: none;
  opacity: 0;
  transition: opacity .15s;
  z-index: 50;
}

/* ─── Topology device tooltip ────────────────────────────────────────────── */
.topo-tooltip {
  position: fixed;
  z-index: 200;
  background: var(--bg-3, #1a1f2e);
  border: 1px solid var(--border, #2d3748);
  border-radius: 8px;
  padding: 8px 11px;
  font-size: .78rem;
  color: var(--text-primary, #e2e8f0);
  pointer-events: none;
  box-shadow: 0 6px 24px rgba(0,0,0,0.5);
  min-width: 160px;
  max-width: 220px;
  transition: opacity .1s;
}
.topo-tooltip.hidden { opacity: 0; pointer-events: none; }
.topo-tooltip .tt-name {
  font-weight: 600;
  font-size: .82rem;
  color: #818cf8;
  margin-bottom: 5px;
  border-bottom: 1px solid var(--border, #2d3748);
  padding-bottom: 4px;
}
.topo-tooltip .tt-row {
  display: flex;
  justify-content: space-between;
  gap: .5rem;
  margin: 2px 0;
  font-size: .74rem;
}
.topo-tooltip .tt-row span:first-child { color: var(--text-muted, #64748b); }
.topo-tooltip .tt-row span:last-child  { color: var(--text-secondary, #94a3b8); font-family: 'Fira Code', monospace; }
.topo-tooltip .tt-up   { color: var(--success, #10b981) !important; }
.topo-tooltip .tt-down { color: var(--error, #ef4444) !important; }

/* ─── Topology zoom buttons ──────────────────────────────────────────────── */
.topo-zoom-btn rect  { transition: fill .15s; }
.topo-zoom-btn:hover rect { fill: #252d3f !important; }
.topo-zoom-btn text  { user-select: none; font-family: 'Inter', sans-serif; }

/* ─── Topology SVG interactive elements ──────────────────────────────────── */
.topo-device-group { transition: filter .2s; }
.topo-device-group:hover { filter: brightness(1.25); }
.topo-link { transition: stroke-opacity .3s; }
#topology-svg { user-select: none; }

/* ─── Packet animation (CLI ping streaming) ──────────────────────────────── */
@keyframes packet-bounce {
  0%, 100% { transform: scale(1); }
  50%       { transform: scale(1.15); }
}
.cli-line.cli-ok { font-family: 'Fira Code', monospace; letter-spacing: .15em; }

/* ─── Trunk port badge on switch panel ───────────────────────────────────── */
.port-badge-trunk {
  display: inline-block;
  font-size: .55rem;
  font-weight: 700;
  letter-spacing: .04em;
  padding: 1px 3px;
  border-radius: 3px;
  background: rgba(99, 102, 241, 0.25);
  color: #818cf8;
  line-height: 1.2;
  margin-top: 1px;
  vertical-align: middle;
}
.port-badge-sec {
  display: inline-block;
  font-size: .55rem;
  font-weight: 700;
  padding: 1px 3px;
  border-radius: 3px;
  background: rgba(245, 158, 11, 0.2);
  color: #f59e0b;
  line-height: 1.2;
  margin-top: 1px;
  vertical-align: middle;
}

/* ─── Interface range prompt ─────────────────────────────────────────────── */
.cli-line.cli-info { color: var(--accent, #818cf8); }
[data-tooltip]:hover::after { opacity: 1; }