/* ============================================================
   IO Brand Tokens
   ============================================================ */
:root {
  /* Brand palette */
  --color-primary: #E52321; /* Infared */
  --color-accent: #EC641D; /* Dawn */
  --color-black: #000000;
  --color-white: #FFFFFF;
  /* Dark-first surfaces */
  --color-surface: #0A0A0A;
  --color-surface-alt: #141414;
  --color-surface-raised: #1A1A1A;
  --color-text: #E8E8E8;
  --color-text-muted: #6B7280;
  --color-border: #2A2A2A;
  /* Secondary brand */
  --color-acid-green: #06FF89;
  --color-electric-blue: #16E9D8;
  --color-ultraviolet: #A700FF;
  --color-volt-yellow: #F2FF58;
  /* Semantic status */
  --status-green: #22C55E;
  --status-amber: #F59E0B;
  --status-red: #EF4444;
  --status-pending: #9CA3AF;
  /* Typography */
  --font-sans: "Barlow", "Bricolage Grotesque", sans-serif;
  --font-mono: "JetBrains Mono", "Fira Code", "Courier New", monospace;
  /* Spacing */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-12: 3rem;
  --space-16: 4rem;
  /* Radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
}

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

html, body {
  height: 100%;
  overflow: hidden;
}

body {
  font-family: var(--font-sans);
  font-size: 0.875rem;
  line-height: 1.5;
  color: var(--color-text);
  background: var(--color-black);
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--color-primary);
  text-decoration: none;
}

code {
  font-family: var(--font-mono);
  font-size: 0.85em;
}

/* ============================================================
   Playground Layout
   ============================================================ */
.playground {
  display: grid;
  grid-template-rows: auto 1fr auto;
  grid-template-columns: 1fr 300px;
  grid-template-areas: "header  header" "canvas  controls" "log     log";
  height: 100vh;
  width: 100vw;
}

/* ============================================================
   Header Bar
   ============================================================ */
.header-bar {
  grid-area: header;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-3) var(--space-6);
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  gap: var(--space-4);
}

.header-left {
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

.header-logo {
  height: 24px;
  width: auto;
  opacity: 0.9;
}

.header-title {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--color-white);
  letter-spacing: -0.01em;
}

.header-stats {
  display: flex;
  align-items: center;
  gap: var(--space-6);
}

.header-stat {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.header-stat-label {
  font-size: 0.75rem;
  font-weight: 400;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.header-stat-value {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-electric-blue);
  font-family: var(--font-mono);
}

/* ============================================================
   Canvas Area
   ============================================================ */
.canvas-area {
  grid-area: canvas;
  position: relative;
  overflow: hidden;
  background: radial-gradient(ellipse at 20% 80%, rgba(174, 20, 15, 0.08), transparent 60%), radial-gradient(ellipse at 80% 20%, rgba(232, 128, 4, 0.05), transparent 60%), var(--color-black);
}

.canvas-area svg {
  width: 100%;
  height: 100%;
  display: block;
}

.canvas-hint {
  position: absolute;
  bottom: var(--space-4);
  left: 50%;
  transform: translateX(-50%);
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  background: rgba(0, 0, 0, 0.7);
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-md);
  pointer-events: none;
}

/* ============================================================
   SVG Elements
   ============================================================ */
/* Links */
.link-line {
  stroke: var(--color-electric-blue);
  stroke-width: 2;
  stroke-opacity: 0.5;
  fill: none;
  transition: stroke-opacity 0.15s;
}

.link-line:hover,
.link-line-selected {
  stroke-opacity: 1;
  stroke-width: 3;
}

.link-line-active {
  stroke: var(--color-accent);
  stroke-opacity: 0.9;
  stroke-width: 3;
  animation: pulse-link 1.5s ease-in-out infinite;
}

@keyframes pulse-link {
  0%, 100% {
    stroke-opacity: 0.6;
    stroke-width: 2.5;
  }
  50% {
    stroke-opacity: 1;
    stroke-width: 3.5;
  }
}
.link-label {
  fill: var(--color-text-muted);
  font-size: 11px;
  font-family: var(--font-mono);
  text-anchor: middle;
  pointer-events: none;
}

/* Node cards */
.node-card {
  fill: var(--color-surface);
  stroke: var(--color-border);
  stroke-width: 1.5;
  cursor: pointer;
}

.node-card:hover {
  stroke: rgba(255, 255, 255, 0.4);
}

.node-card-selected {
  stroke: var(--color-white);
  stroke-width: 2;
}

.node-card-pending {
  stroke: var(--color-accent);
  stroke-width: 2;
  stroke-dasharray: 4 4;
}

.node-card-label {
  fill: var(--color-white);
  font-size: 11px;
  font-weight: 600;
  text-anchor: middle;
  pointer-events: none;
  font-family: var(--font-sans);
}

.node-gauge-label {
  fill: var(--color-text-muted);
  font-size: 7px;
  font-family: var(--font-mono);
  pointer-events: none;
}

/* SVG gauge backgrounds */
.svg-gauge-bg {
  fill: var(--color-border);
}

/* Link direction arrows */
.link-gauge-arrow {
  fill: var(--color-text-muted);
  font-size: 7px;
  text-anchor: middle;
  pointer-events: none;
}

/* Flow streams (data in transit) */
.flow-stream {
  stroke: var(--color-accent);
  stroke-width: 5;
  stroke-opacity: 0.85;
  fill: none;
}

/* Packets (animated dots) */
.packet-dot {
  fill: var(--color-primary);
  r: 6;
}

@keyframes pulse-packet {
  0%, 100% {
    r: 5;
    opacity: 1;
  }
  50% {
    r: 8;
    opacity: 0.7;
  }
}
.packet-dot {
  animation: pulse-packet 0.8s ease-in-out infinite;
}

/* ============================================================
   Control Panel (Sidebar)
   ============================================================ */
.control-panel {
  grid-area: controls;
  background: var(--color-surface);
  border-left: 1px solid var(--color-border);
  overflow-y: auto;
  display: flex;
  flex-direction: column;
}

.control-section {
  padding: var(--space-4);
  border-bottom: 1px solid var(--color-border);
}

.control-section-title {
  font-size: 0.6875rem;
  font-weight: 500;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: var(--space-3);
}

/* Mode selector */
.mode-selector {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-2);
}

.mode-btn {
  padding: var(--space-2) var(--space-3);
  font-family: var(--font-sans);
  font-size: 0.8125rem;
  font-weight: 500;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border);
  background: transparent;
  color: var(--color-text-muted);
  cursor: pointer;
  transition: all 0.15s;
  text-align: center;
}

.mode-btn:hover {
  border-color: rgba(255, 255, 255, 0.3);
  color: var(--color-text);
}

.mode-btn-active {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-white);
}

/* Parameter groups */
.param-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  margin-bottom: var(--space-3);
}

.param-label {
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--color-text-muted);
}

.param-value {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--color-electric-blue);
  font-family: var(--font-mono);
}

.param-input {
  width: 100%;
  padding: var(--space-2);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  background: var(--color-surface-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  color: var(--color-text);
  outline: none;
  transition: border-color 0.15s;
}

.param-input:focus {
  border-color: var(--color-electric-blue);
}

.param-input[type=range] {
  padding: 0;
  height: 6px;
  -webkit-appearance: none;
  appearance: none;
  background: var(--color-border);
  border: none;
  border-radius: 3px;
  cursor: pointer;
}

.param-input[type=range]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--color-electric-blue);
  border: 2px solid var(--color-surface);
  cursor: pointer;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  font-family: var(--font-sans);
  font-size: 0.8125rem;
  font-weight: 500;
  border-radius: var(--radius-sm);
  border: none;
  cursor: pointer;
  transition: opacity 0.15s, background 0.15s;
  line-height: 1;
  white-space: nowrap;
}

.btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.btn-primary {
  background: var(--color-primary);
  color: var(--color-white);
}

.btn-primary:hover:not(:disabled) {
  opacity: 0.88;
}

.btn-secondary {
  background: var(--color-surface-raised);
  color: var(--color-text);
  border: 1px solid var(--color-border);
}

.btn-secondary:hover:not(:disabled) {
  border-color: rgba(255, 255, 255, 0.3);
}

.btn-accent {
  background: var(--color-acid-green);
  color: var(--color-black);
}

.btn-accent:hover:not(:disabled) {
  opacity: 0.88;
}

.btn-full {
  width: 100%;
}

/* Simulation controls */
.sim-controls {
  display: flex;
  gap: var(--space-2);
}

.sim-controls .btn {
  flex: 1;
}

/* Info block */
.info-block {
  background: var(--color-surface-alt);
  border-radius: var(--radius-sm);
  padding: var(--space-3);
}

.info-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-1) 0;
}

.info-row-label {
  font-size: 0.75rem;
  color: var(--color-text-muted);
}

.info-row-value {
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--color-text);
  font-family: var(--font-mono);
}

.no-selection {
  text-align: center;
  padding: var(--space-4);
  color: var(--color-text-muted);
  font-size: 0.8125rem;
}

/* Gauge bars */
.gauge-bar {
  height: 6px;
  background: var(--color-border);
  border-radius: 3px;
  overflow: hidden;
}

.gauge-fill {
  height: 100%;
  border-radius: 3px;
  transition: width 0.3s ease, background-color 0.3s ease;
}

.gauge-fill-ok {
  background: var(--color-acid-green);
}

.gauge-fill-warn {
  background: var(--status-amber);
}

.gauge-fill-critical {
  background: var(--status-red);
}

/* Preset buttons */
.preset-buttons {
  display: flex;
  gap: var(--space-2);
  flex-wrap: wrap;
}

.btn-small {
  padding: var(--space-1) var(--space-2);
  font-size: 0.6875rem;
  background: var(--color-surface-raised);
  color: var(--color-text-muted);
  border: 1px solid var(--color-border);
  font-family: var(--font-mono);
}

.btn-small:hover:not(:disabled) {
  border-color: var(--color-electric-blue);
  color: var(--color-text);
}

/* Readonly param values */
.param-readonly {
  font-size: 0.6875rem;
  color: var(--color-text-muted);
  font-family: var(--font-mono);
}

/* Input validation */
.param-input-error {
  border-color: var(--status-red) !important;
}

.param-error {
  font-size: 0.6875rem;
  color: var(--status-red);
  font-family: var(--font-mono);
}

/* ============================================================
   Transit Status Table
   ============================================================ */
.transit-table {
  grid-area: log;
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  max-height: 200px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
}

.transit-table-header {
  display: flex;
  align-items: center;
  padding: var(--space-2) var(--space-4);
  font-size: 0.6875rem;
  font-weight: 500;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  background: var(--color-surface);
  z-index: 1;
}

.transit-table-body {
  flex: 1;
  overflow-y: auto;
}

.transit-row {
  display: flex;
  align-items: center;
  padding: var(--space-1) var(--space-4);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  border-bottom: 1px solid var(--color-border);
}

.transit-row:hover {
  background: var(--color-surface-alt);
}

.transit-row-delivered {
  opacity: 0.45;
}

.transit-row-dropped {
  opacity: 0.45;
}

.transit-col {
  padding: 0 var(--space-2);
  flex-shrink: 0;
}

.transit-col-id {
  width: 60px;
  color: var(--color-text-muted);
}

.transit-col-route {
  width: 150px;
  color: var(--color-text);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.transit-col-stage {
  width: 160px;
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

.transit-stage-label {
  width: 18px;
  font-size: 0.625rem;
  color: var(--color-text-muted);
  flex-shrink: 0;
}

.transit-gauge {
  width: 50px;
  height: 6px;
  background: var(--color-border);
  border-radius: 3px;
  overflow: hidden;
  flex-shrink: 0;
}

.transit-gauge-fill {
  display: block;
  height: 100%;
  border-radius: 3px;
  transition: width 0.15s ease;
}

.transit-stage-bytes {
  font-size: 0.625rem;
  color: var(--color-text-muted);
  min-width: 50px;
}

.transit-status {
  width: 60px;
  font-size: 0.625rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  flex-shrink: 0;
}

.transit-status-active {
  color: var(--color-electric-blue);
}

.transit-status-delivered {
  color: var(--status-green);
}

.transit-status-dropped {
  color: var(--status-red);
}

.transit-empty {
  padding: var(--space-4) var(--space-6);
  text-align: center;
  color: var(--color-text-muted);
  font-size: 0.8125rem;
}

/* ============================================================
   Scrollbar Styling
   ============================================================ */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: var(--color-border);
  border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--color-text-muted);
}