/* ================================================
   Signal Degradation Visualizer
   Theme: Phosphor Terminal / Lab Oscilloscope
   ================================================ */

/* ---------- DESIGN TOKENS ---------- */
:root {
  --bg-base:       #0f1117;
  --bg-panel:      #161b26;
  --bg-panel-deep: #111520;
  --border:        #252d3d;
  --border-bright: #2e3a50;

  --amber:         #e8a838;
  --amber-dim:     #7a5212;
  --amber-glow:    rgba(232,168,56,0.12);
  --green:         #39d98a;
  --green-dim:     #1a4d35;
  --orange:        #f07d3a;
  --red:           #e84545;
  --gray:          #5a6679;

  --text-primary:  #e4edf8;
  --text-secondary:#a5b7d5;
  --text-dim:      #7a8baf;

  --mono:          'JetBrains Mono', 'Fira Code', monospace;
  --display:       'Syne', sans-serif;

  --radius-sm: 3px;
  --radius:    6px;
  --radius-lg: 10px;

  --transition: 150ms ease;
}

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

html { font-size: 14px; }

body {
  font-family: var(--mono);
  background: var(--bg-base);
  color: var(--text-primary);
  min-height: 100vh;
  overflow-x: hidden;
  position: relative;
}

/* Subtle noise texture overlay */
.noise-overlay {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  opacity: 0.025;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)'/%3E%3C/svg%3E");
  background-repeat: repeat;
  background-size: 128px 128px;
}

/* ---------- HEADER ---------- */
.site-header {
  position: relative;
  z-index: 10;
  display: flex;
  align-items: center;
  gap: 24px;
  padding: 20px 32px 18px;
  border-bottom: 1px solid var(--border);
  background: linear-gradient(180deg, #13192600 0%, var(--bg-base) 100%);
}

.header-badge {
  font-family: var(--mono);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 3px;
  color: var(--amber);
  background: var(--amber-glow);
  border: 1px solid var(--amber-dim);
  padding: 5px 10px;
  border-radius: var(--radius-sm);
  white-space: nowrap;
  flex-shrink: 0;
}

.header-center { flex: 1; text-align: center; }

h1 {
  font-family: var(--display);
  font-size: 2.1rem;
  font-weight: 800;
  letter-spacing: -0.5px;
  color: var(--text-primary);
  line-height: 1.05;
  margin-bottom: 6px;
}

.subtitle {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--text-secondary);
  margin-top: 5px;
  letter-spacing: 0.5px;
}

.header-status {
  display: flex;
  align-items: center;
  gap: 7px;
  font-size: 10px;
  letter-spacing: 2px;
  color: var(--green);
  flex-shrink: 0;
}

.status-dot {
  width: 7px; height: 7px;
  border-radius: 50%;
  background: var(--green);
  animation: pulse-dot 2s ease-in-out infinite;
  box-shadow: 0 0 8px var(--green);
}

@keyframes pulse-dot {
  0%, 100% { opacity: 1; }
  50%       { opacity: 0.35; }
}

/* ---------- MAIN LAYOUT ---------- */
main.layout {
  position: relative;
  z-index: 1;
  max-width: 900px;
  margin: 0 auto;
  padding: 28px 24px 48px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

/* ---------- PANEL ---------- */
.panel {
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: border-color var(--transition);
}

.panel:hover { border-color: var(--border-bright); }

.panel-label {
  font-family: var(--mono);
  font-size: 9.5px;
  font-weight: 700;
  letter-spacing: 2.5px;
  color: var(--text-secondary);
  text-transform: uppercase;
  padding: 8px 18px 7px;
  border-bottom: 1px solid var(--border);
  background: var(--bg-panel-deep);
}

.panel-body {
  padding: 18px 20px;
}

/* ---------- STEP 1 — MESSAGE INPUT ---------- */
.field-label {
  display: block;
  font-size: 10px;
  letter-spacing: 1.5px;
  color: var(--text-primary);
  text-transform: uppercase;
  margin-bottom: 10px;
}

.input-wrap {
  display: flex;
  align-items: center;
  background: var(--bg-panel-deep);
  border: 1px solid var(--border-bright);
  border-radius: var(--radius);
  overflow: hidden;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.input-wrap:focus-within {
  border-color: var(--amber);
  box-shadow: 0 0 0 3px var(--amber-glow);
}

.input-prefix {
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 700;
  color: var(--amber);
  padding: 10px 14px;
  border-right: 1px solid var(--border);
  white-space: nowrap;
  background: rgba(232,168,56,0.05);
  user-select: none;
}

#msgInput {
  flex: 1;
  background: transparent;
  border: none;
  outline: none;
  font-family: var(--mono);
  font-size: 14px;
  color: var(--text-primary);
  padding: 10px 14px;
  caret-color: var(--amber);
}

#msgInput::placeholder { color: var(--text-dim); }

/* ---------- STEP 2 — MEDIUM BUTTONS ---------- */
#mediumBtns {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
  margin-bottom: 14px;
}

.mbtn {
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 500;
  padding: 7px 14px;
  background: var(--bg-panel-deep);
  border: 1px solid var(--border-bright);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  cursor: pointer;
  letter-spacing: 0.5px;
  transition: all var(--transition);
  position: relative;
}

.mbtn:hover {
  background: rgba(232,168,56,0.07);
  border-color: var(--amber-dim);
  color: var(--amber);
}

.mbtn.active {
  background: var(--amber-glow);
  border-color: var(--amber);
  color: var(--amber);
  box-shadow: 0 0 12px var(--amber-glow);
}

/* Obstacle checkbox */
#losBox {
  margin-top: 4px;
  padding-top: 14px;
  border-top: 1px solid var(--border);
}

.obstacle-label {
  display: flex;
  align-items: center;
  gap: 10px;
  cursor: pointer;
  font-size: 11.5px;
  color: var(--text-primary);
  user-select: none;
}

.obstacle-label input[type="checkbox"] { display: none; }

.checkbox-custom {
  width: 16px; height: 16px;
  border: 1px solid var(--border-bright);
  border-radius: 3px;
  background: var(--bg-panel-deep);
  flex-shrink: 0;
  position: relative;
  transition: all var(--transition);
}

.obstacle-label input:checked + .checkbox-custom {
  background: var(--amber-glow);
  border-color: var(--amber);
}

.obstacle-label input:checked + .checkbox-custom::after {
  content: '✓';
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 11px;
  color: var(--amber);
  font-weight: 700;
}

/* ---------- STEP 3 — DISTANCE ---------- */
.dist-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 12px;
}

.dist-val {
  font-family: var(--mono);
  font-size: 18px;
  font-weight: 700;
  color: var(--amber);
  letter-spacing: 0.5px;
  min-width: 80px;
  text-align: right;
}

/* Custom range slider */
#distSlider {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 3px;
  background: var(--border-bright);
  border-radius: 2px;
  outline: none;
  cursor: pointer;
  display: block;
}

#distSlider::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 18px; height: 18px;
  border-radius: 50%;
  background: var(--amber);
  box-shadow: 0 0 10px var(--amber-glow), 0 0 4px rgba(0,0,0,0.6);
  cursor: pointer;
  transition: transform 0.1s ease, box-shadow 0.1s ease;
}

#distSlider::-webkit-slider-thumb:hover {
  transform: scale(1.2);
  box-shadow: 0 0 18px rgba(232,168,56,0.5), 0 0 4px rgba(0,0,0,0.6);
}

#distSlider::-moz-range-thumb {
  width: 18px; height: 18px;
  border-radius: 50%;
  background: var(--amber);
  border: none;
  box-shadow: 0 0 10px var(--amber-glow);
  cursor: pointer;
}

.dist-marks {
  display: flex;
  justify-content: space-between;
  font-size: 9.5px;
  color: var(--text-secondary);
  margin-top: 8px;
  letter-spacing: 0.5px;
}

/* ---------- OSCILLOSCOPE CANVAS ---------- */
.wave-legend {
  display: flex;
  gap: 24px;
  margin-bottom: 10px;
}

.legend-item {
  font-size: 10px;
  letter-spacing: 1px;
  color: var(--text-secondary);
}

.legend-item.ghost   { color: rgba(160,160,160,0.45); }
.legend-item.received { color: var(--amber); }

.canvas-wrap {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
}

/* Scanline grid overlay on canvas */
.canvas-grid {
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(57,217,138,0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(57,217,138,0.03) 1px, transparent 1px);
  background-size: 36px 22px;
}

#wave {
  width: 100%;
  display: block;
  background: #090c12;
}

/* ---------- STATS PANEL ---------- */
.stats {
  display: grid;
  grid-template-columns: 1fr auto 1fr auto 1fr auto 1fr;
  align-items: center;
  gap: 0;
}

.stat-divider {
  width: 1px;
  height: 60px;
  background: var(--border);
  margin: 0 20px;
}

.stat { text-align: center; }

.slabel {
  font-size: 9px;
  letter-spacing: 2px;
  color: var(--text-dim);
  text-transform: uppercase;
  margin-bottom: 6px;
}

.sval {
  font-family: var(--mono);
  font-size: 22px;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1;
  transition: color 0.3s ease;
}

.sval.ok   { color: var(--green);  text-shadow: 0 0 16px rgba(57,217,138,0.4); }
.sval.warn { color: var(--orange); text-shadow: 0 0 16px rgba(240,125,58,0.4); }
.sval.bad  { color: var(--red);    text-shadow: 0 0 16px rgba(232,69,69,0.4); }

/* Mini bar under stat values */
.sbar-wrap {
  height: 2px;
  background: var(--border);
  border-radius: 1px;
  margin-top: 8px;
  overflow: hidden;
}

.sbar {
  height: 100%;
  border-radius: 1px;
  background: var(--green);
  width: 100%;
  transition: width 0.3s ease, background 0.3s ease;
}

/* Link status badge dot */
.status-badge {
  font-size: 18px;
  margin-top: 6px;
  color: var(--green);
  text-shadow: 0 0 12px rgba(57,217,138,0.6);
  transition: color 0.3s ease, text-shadow 0.3s ease;
}

.status-badge.warn { color: var(--orange); text-shadow: 0 0 12px rgba(240,125,58,0.6); }
.status-badge.bad  { color: var(--red);    text-shadow: 0 0 12px rgba(232,69,69,0.6); }

/* ---------- MESSAGE COMPARISON ---------- */
.compare {
  display: flex;
  align-items: center;
  gap: 0;
  margin: 4px 0 16px;
}

.compare-side { flex: 1; }

.clabel {
  font-size: 9.5px;
  letter-spacing: 2px;
  color: var(--text-secondary);
  text-transform: uppercase;
  margin-bottom: 8px;
}

.msg {
  font-family: var(--mono);
  font-size: 18px;
  font-weight: 700;
  min-height: 26px;
  letter-spacing: 2.5px;
  line-height: 1.4;
  word-break: break-all;
}

/* Arrow between host A and B */
.arrow-wrap {
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 3px;
  padding: 0 20px;
}

.arrow-line {
  width: 60px;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--border-bright), transparent);
}

.arrow-head {
  font-size: 18px;
  color: var(--text-primary);
  line-height: 1;
}

.arrow-label {
  font-size: 8.5px;
  letter-spacing: 1.5px;
  color: var(--text-secondary);
  text-transform: uppercase;
  white-space: nowrap;
}

/* Color key */
.key {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  font-size: 10px;
  letter-spacing: 1px;
  padding-top: 14px;
  border-top: 1px solid var(--border);
}

.key .ok   { color: var(--green); }
.key .warn { color: var(--orange); }
.key .bad  { color: var(--red); }
.key .dead { color: var(--gray); }

/* Char coloring from JS */
span.ok   { color: var(--green); }
span.warn { color: var(--orange); }
span.bad  { color: var(--red); }
span.dead { color: var(--gray); }

/* ---------- MEDIUM INFO ---------- */
.medinfo {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--text-primary);
  line-height: 1.75;
  letter-spacing: 0.2px;
}

/* ---------- FOOTER ---------- */
.site-footer {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: 20px;
  font-size: 10px;
  letter-spacing: 2px;
  color: var(--text-secondary);
  border-top: 1px solid var(--border);
  text-transform: uppercase;
}

.footer-sep { margin: 0 12px; color: var(--border-bright); }

/* ---------- RESPONSIVE ---------- */
@media (max-width: 640px) {
  .site-header { padding: 16px; flex-wrap: wrap; gap: 12px; }
  h1 { font-size: 1.3rem; }
  main.layout { padding: 18px 14px 40px; }

  .stats {
    grid-template-columns: 1fr 1fr;
    gap: 20px;
  }
  .stat-divider { display: none; }

  .compare { flex-direction: column; gap: 16px; }
  .arrow-wrap { transform: rotate(90deg); }
  .arrow-line { width: 40px; }

  .sval { font-size: 18px; }
}