/* Laboratory of Fields & Resonance — UI Stylesheet
   Visual language: Ancient natural philosophy + futuristic research lab
   Colors: Dark stone · Bronze trim · Teal fields · Gold equipotentials */

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

:root {
  --teal:    #00e5ff;
  --gold:    #ffd700;
  --red-pos: #ff4444;
  --blue-neg: #4488ff;
  --bronze:  #cd7f32;
  --stone:   #141420;
  --dark:    #07080f;
  --panel-bg: rgba(4, 8, 18, 0.88);
  --panel-border: rgba(0, 200, 220, 0.2);
  --text:    #c8dce8;
  --text-dim: #5a7080;
  --mono:    'Courier New', Courier, monospace;
}

html, body {
  width: 100%;
  height: 100%;
  overflow: hidden;
  background: var(--dark);
  color: var(--text);
  font-family: var(--mono);
  font-size: 13px;
}

/* ── Canvas ──────────────────────────────────────────────────────────────── */

#lab-canvas {
  position: fixed;
  top: 0; left: 0;
  width: 100%; height: 100%;
  display: block;
}

/* ── Loading Screen ──────────────────────────────────────────────────────── */

#loading-screen {
  position: fixed;
  inset: 0;
  background: var(--dark);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  transition: opacity 0.6s ease;
}

#loading-screen.fade-out { opacity: 0; pointer-events: none; }

.loading-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
  max-width: 440px;
  text-align: center;
  padding: 40px;
}

.lab-sigil {
  font-size: 52px;
  color: var(--teal);
  text-shadow: 0 0 24px var(--teal), 0 0 48px rgba(0,229,255,0.3);
  animation: pulse-sigil 2.4s ease-in-out infinite;
}

@keyframes pulse-sigil {
  0%, 100% { text-shadow: 0 0 24px var(--teal), 0 0 48px rgba(0,229,255,0.3); }
  50%       { text-shadow: 0 0 40px var(--teal), 0 0 80px rgba(0,229,255,0.5); }
}

.loading-inner h1 {
  font-size: 22px;
  font-weight: bold;
  color: var(--teal);
  letter-spacing: 1px;
  line-height: 1.3;
}

.loading-inner > p {
  color: var(--text-dim);
  font-size: 12px;
  letter-spacing: 2px;
  text-transform: uppercase;
}

.loading-bar {
  width: 300px;
  height: 2px;
  background: rgba(0,200,220,0.15);
  border-radius: 2px;
  overflow: hidden;
}

#loading-progress {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, #004466, var(--teal));
  transition: width 0.3s ease;
  box-shadow: 0 0 8px var(--teal);
}

#loading-status {
  font-size: 11px;
  color: var(--text-dim);
  min-height: 16px;
}

#enter-lab-btn {
  margin-top: 12px;
  padding: 10px 32px;
  background: transparent;
  border: 1px solid var(--teal);
  color: var(--teal);
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 2px;
  cursor: pointer;
  transition: all 0.2s;
}

#enter-lab-btn:hover {
  background: rgba(0,229,255,0.12);
  box-shadow: 0 0 16px rgba(0,229,255,0.3);
}

/* ── Click-to-start overlay ─────────────────────────────────────────────── */

#click-to-start {
  position: fixed;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 500;
  pointer-events: auto;
  cursor: pointer;
  background: rgba(3,5,12,0.7);
  backdrop-filter: blur(2px);
}

.cts-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  text-align: center;
}

.cts-inner h2 {
  font-size: 20px;
  color: var(--teal);
  letter-spacing: 1px;
}

.cts-inner p {
  font-size: 14px;
  color: var(--text-dim);
}

.cts-hint {
  font-size: 11px;
  color: #3a5060;
  letter-spacing: 1px;
}

/* ── UI Root ─────────────────────────────────────────────────────────────── */

#ui-root {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 100;
}

/* ── Lab title (top left) ─────────────────────────────────────────────────── */

#lab-title {
  position: absolute;
  top: 16px; left: 16px;
  display: flex;
  flex-direction: column;
  gap: 3px;
}

.lab-name {
  font-size: 14px;
  font-weight: bold;
  color: var(--teal);
  letter-spacing: 0.5px;
}

.lab-sub {
  font-size: 10px;
  color: var(--text-dim);
  letter-spacing: 1px;
  text-transform: uppercase;
}

/* ── Mode panel (top right) ─────────────────────────────────────────────── */

#mode-panel {
  position: absolute;
  top: 16px; right: 16px;
  text-align: right;
}

.mode-label {
  font-size: 14px;
  font-weight: bold;
  letter-spacing: 1px;
}

.mode-desc {
  font-size: 10px;
  color: var(--text-dim);
  margin-top: 2px;
}

/* ── Simulation status (bottom left) ────────────────────────────────────── */

#sim-status {
  position: absolute;
  bottom: 20px; left: 16px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

#sim-name {
  font-size: 12px;
  color: var(--gold);
  letter-spacing: 1px;
}

#charge-count {
  font-size: 11px;
  color: var(--text-dim);
}

/* ── Controls reference (bottom right, toggleable) ───────────────────────── */

#controls-ref {
  position: absolute;
  bottom: 16px; right: 16px;
  display: flex;
  gap: 18px;
  pointer-events: auto;
}

#controls-ref.hidden { display: none; }

.ctrl-group {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.ctrl-header {
  font-size: 9px;
  letter-spacing: 2px;
  color: var(--teal);
  text-transform: uppercase;
  margin-bottom: 2px;
  border-bottom: 1px solid rgba(0,229,255,0.2);
  padding-bottom: 2px;
}

.ctrl-row {
  font-size: 11px;
  color: var(--text-dim);
  display: flex;
  align-items: center;
  gap: 6px;
}

kbd {
  background: rgba(0,200,220,0.12);
  border: 1px solid rgba(0,200,220,0.25);
  border-radius: 2px;
  padding: 1px 5px;
  font-family: var(--mono);
  font-size: 10px;
  color: var(--teal);
  white-space: nowrap;
}

/* ── Crosshair ───────────────────────────────────────────────────────────── */

#crosshair {
  position: absolute;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  font-size: 20px;
  color: #ffffff;
  line-height: 1;
  display: none;
  pointer-events: none;
  text-shadow: 0 0 6px rgba(0,229,255,0.6);
  transition: color 0.15s;
}

/* ── Notification ────────────────────────────────────────────────────────── */

#notification {
  position: absolute;
  top: 50%; left: 50%;
  transform: translate(-50%, calc(-50% + 48px));
  background: rgba(0,8,20,0.9);
  border: 1px solid rgba(0,229,255,0.3);
  color: var(--teal);
  font-size: 12px;
  letter-spacing: 1px;
  padding: 7px 18px;
  border-radius: 2px;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s;
  text-align: center;
}

#notification.show { opacity: 1; }

/* ── Info Panel (student mode equations) ────────────────────────────────── */

#info-panel {
  position: absolute;
  top: 60px; right: 16px;
  width: 220px;
  background: var(--panel-bg);
  border: 1px solid var(--panel-border);
  padding: 14px;
  display: none;
}

#info-panel.active { display: block; }

.info-header {
  font-size: 10px;
  letter-spacing: 2px;
  color: var(--teal);
  text-transform: uppercase;
  border-bottom: 1px solid rgba(0,229,255,0.2);
  padding-bottom: 6px;
  margin-bottom: 10px;
}

.eq-block { margin-bottom: 10px; }

.eq-title {
  font-size: 10px;
  color: var(--text-dim);
  margin-bottom: 3px;
}

.eq {
  font-size: 15px;
  color: var(--gold);
  letter-spacing: 0.5px;
}

.eq-sub {
  font-size: 10px;
  color: var(--text-dim);
  margin-top: 2px;
}

/* ── Expert Panel ────────────────────────────────────────────────────────── */

#expert-panel {
  position: absolute;
  top: 60px; right: 16px;
  width: 260px;
  max-height: calc(100vh - 80px);
  overflow-y: auto;
  background: var(--panel-bg);
  border: 1px solid rgba(255,170,0,0.25);
  display: none;
  pointer-events: auto;
  scrollbar-width: thin;
  scrollbar-color: #333 transparent;
}

#expert-panel.active { display: block; }

.expert-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 14px;
  border-bottom: 1px solid rgba(255,170,0,0.2);
  position: sticky;
  top: 0;
  background: var(--panel-bg);
}

.expert-title {
  font-size: 11px;
  letter-spacing: 1.5px;
  color: #ffaa00;
  text-transform: uppercase;
}

.expert-close {
  background: none;
  border: none;
  color: var(--text-dim);
  cursor: pointer;
  font-size: 12px;
  font-family: var(--mono);
}

.expert-close:hover { color: var(--teal); }

.expert-section {
  padding: 10px 14px;
  border-bottom: 1px solid rgba(255,255,255,0.05);
}

.expert-section-title {
  font-size: 9px;
  letter-spacing: 2px;
  color: var(--text-dim);
  text-transform: uppercase;
  margin-bottom: 8px;
}

.expert-row {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 8px;
}

.expert-row label {
  font-size: 10px;
  color: var(--text-dim);
  min-width: 110px;
}

.expert-row input[type="range"] {
  flex: 1;
  -webkit-appearance: none;
  height: 2px;
  background: rgba(0,229,255,0.2);
  border-radius: 2px;
  cursor: pointer;
}

.expert-row input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--teal);
}

.expert-row span {
  font-size: 10px;
  color: var(--teal);
  min-width: 30px;
  text-align: right;
}

.readout {
  font-size: 11px;
  color: #88ccaa;
  margin-bottom: 4px;
  font-family: var(--mono);
}

.charge-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 11px;
  padding: 3px 0;
  color: var(--text-dim);
}

.charge-item.pos { color: var(--red-pos); }
.charge-item.neg { color: var(--blue-neg); }

.del-charge {
  background: none;
  border: none;
  color: #443333;
  cursor: pointer;
  font-size: 10px;
  font-family: var(--mono);
  padding: 0 4px;
}

.del-charge:hover { color: #ff4444; }

.exp-btn {
  display: block;
  width: 100%;
  padding: 7px;
  background: rgba(0,229,255,0.08);
  border: 1px solid rgba(0,229,255,0.25);
  color: var(--teal);
  font-family: var(--mono);
  font-size: 11px;
  cursor: pointer;
  letter-spacing: 1px;
  margin-bottom: 6px;
  transition: background 0.15s;
}

.exp-btn:hover { background: rgba(0,229,255,0.18); }

.exp-btn.danger {
  border-color: rgba(255,60,60,0.3);
  color: #ff6666;
  background: rgba(255,40,40,0.06);
}

.exp-btn.danger:hover { background: rgba(255,40,40,0.15); }

/* ── Safety panel ────────────────────────────────────────────────────────── */

#safety-panel {
  position: absolute;
  bottom: 60px; left: 16px;
  width: 280px;
  background: rgba(4,8,18,0.85);
  border: 1px solid rgba(255,200,0,0.15);
  padding: 12px 14px;
  display: none;
}

#safety-panel.active { display: block; }

.safety-title {
  font-size: 9px;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--gold);
  margin-bottom: 8px;
}

.safety-row {
  font-size: 10px;
  color: var(--text-dim);
  margin-bottom: 4px;
  line-height: 1.5;
}

.si-label {
  color: rgba(255,200,50,0.7);
  margin-right: 4px;
}

/* ── VR Button override ──────────────────────────────────────────────────── */

#vr-button {
  position: fixed !important;
  bottom: 20px !important;
  left: 50% !important;
  transform: translateX(-50%) !important;
  background: rgba(0,0,0,0.7) !important;
  border: 1px solid var(--teal) !important;
  color: var(--teal) !important;
  font-family: var(--mono) !important;
  letter-spacing: 2px !important;
}

/* ── Presets panel (bottom center) ──────────────────────────────────────── */

#presets-panel {
  position: absolute;
  bottom: 16px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  align-items: center;
  gap: 6px;
  pointer-events: auto;
  background: rgba(4,8,18,0.82);
  border: 1px solid rgba(0,200,220,0.18);
  padding: 7px 12px;
}

.presets-title {
  font-size: 9px;
  letter-spacing: 2px;
  color: var(--text-dim);
  text-transform: uppercase;
  margin-right: 4px;
}

.preset-btn {
  background: rgba(0,200,220,0.08);
  border: 1px solid rgba(0,200,220,0.2);
  color: var(--text-dim);
  font-family: var(--mono);
  font-size: 11px;
  padding: 5px 10px;
  cursor: pointer;
  transition: all 0.15s;
  white-space: nowrap;
}

.preset-btn:hover {
  background: rgba(0,229,255,0.18);
  color: var(--teal);
  border-color: var(--teal);
}

/* ── Mode buttons (always-visible, pointer-lock-safe) ───────────────────── */

#mode-btns {
  position: absolute;
  top: 50%;
  left: 16px;
  transform: translateY(-50%);
  display: flex;
  flex-direction: column;
  gap: 6px;
  pointer-events: auto;
}

.mbtn {
  width: 32px;
  height: 32px;
  background: rgba(4,8,18,0.8);
  border: 1px solid rgba(0,200,220,0.2);
  color: var(--text-dim);
  font-family: var(--mono);
  font-size: 12px;
  cursor: pointer;
  transition: all 0.15s;
  display: flex;
  align-items: center;
  justify-content: center;
}

.mbtn:hover {
  border-color: var(--teal);
  color: var(--teal);
  background: rgba(0,229,255,0.1);
  box-shadow: 0 0 8px rgba(0,229,255,0.2);
}

/* ── Scrollbar ───────────────────────────────────────────────────────────── */

::-webkit-scrollbar { width: 4px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: #1a2a3a; border-radius: 2px; }