:root {
  --bg-main: #0b0f19;
  --bg-card: #131b2e;
  --bg-card-hover: #1a243d;
  --border-color: #232f48;
  --primary: #3b82f6;
  --primary-hover: #2563eb;
  --success: #10b981;
  --warning: #f59e0b;
  --danger: #ef4444;
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  --radius: 12px;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
}

body {
  background-color: var(--bg-main);
  color: var(--text-main);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Header */
header {
  background: rgba(19, 27, 46, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  padding: 16px 28px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: sticky;
  top: 0;
  z-index: 100;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand-icon {
  width: 38px;
  height: 38px;
  background: linear-gradient(135deg, #3b82f6, #8b5cf6);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  box-shadow: 0 4px 12px rgba(59, 130, 246, 0.35);
}

.brand-title h1 {
  font-size: 1.2rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.brand-title span {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.header-status {
  display: flex;
  align-items: center;
  gap: 12px;
}

.status-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  border-radius: 9999px;
  font-size: 0.82rem;
  font-weight: 600;
  background: #1e293b;
  border: 1px solid var(--border-color);
}

.dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
}

.dot-green { background: #10b981; box-shadow: 0 0 8px #10b981; }
.dot-red { background: #ef4444; box-shadow: 0 0 8px #ef4444; }
.dot-yellow { background: #f59e0b; box-shadow: 0 0 8px #f59e0b; }

/* Navigation Tabs */
.nav-tabs {
  display: flex;
  gap: 8px;
  padding: 12px 28px;
  background: #0f1626;
  border-bottom: 1px solid var(--border-color);
  overflow-x: auto;
}

.nav-tab {
  background: transparent;
  border: none;
  color: var(--text-muted);
  padding: 10px 18px;
  border-radius: 8px;
  font-size: 0.92rem;
  font-weight: 500;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 8px;
  transition: all 0.2s;
  white-space: nowrap;
}

.nav-tab:hover {
  background: #1a243d;
  color: var(--text-main);
}

.nav-tab.active {
  background: var(--primary);
  color: #fff;
  font-weight: 600;
  box-shadow: 0 2px 8px rgba(59, 130, 246, 0.4);
}

/* Layout */
main {
  flex: 1;
  padding: 28px;
  max-width: 1400px;
  margin: 0 auto;
  width: 100%;
}

.tab-content {
  display: none;
  animation: fadeIn 0.25s ease-in-out;
}

.tab-content.active {
  display: block;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}

/* KPI Cards Grid */
.kpi-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
  margin-bottom: 28px;
}

.kpi-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 20px;
  position: relative;
  overflow: hidden;
  transition: transform 0.2s, border-color 0.2s;
}

.kpi-card:hover {
  transform: translateY(-2px);
  border-color: #3b82f666;
}

.kpi-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--text-muted);
  font-size: 0.85rem;
  font-weight: 500;
  margin-bottom: 10px;
}

.kpi-value {
  font-size: 1.85rem;
  font-weight: 700;
  color: var(--text-main);
}

.kpi-sub {
  font-size: 0.8rem;
  color: var(--text-dim);
  margin-top: 6px;
}

/* Panels */
.card-panel {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 24px;
  margin-bottom: 24px;
}

.card-title {
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 18px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

/* Tables */
.table-responsive {
  overflow-x: auto;
}

table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
}

th {
  background: #0f172a;
  padding: 12px 16px;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-dim);
  border-bottom: 1px solid var(--border-color);
}

td {
  padding: 14px 16px;
  font-size: 0.9rem;
  border-bottom: 1px solid #1a233a;
  color: #cbd5e1;
}

tr:hover td {
  background: var(--bg-card-hover);
}

/* Badges */
.badge {
  padding: 4px 10px;
  border-radius: 6px;
  font-size: 0.78rem;
  font-weight: 600;
  display: inline-block;
}

.badge-video { background: #1e3a8a; color: #93c5fd; }
.badge-audio { background: #3b0764; color: #d8b4fe; }
.badge-active { background: #064e3b; color: #6ee7b7; }
.badge-host { background: #374151; color: #e5e7eb; }
.badge-srflx { background: #075985; color: #7dd3fc; }
.badge-relay { background: #7c2d12; color: #fdba74; }

/* Buttons */
.btn {
  background: var(--primary);
  color: #fff;
  border: none;
  padding: 9px 18px;
  border-radius: 8px;
  font-size: 0.88rem;
  font-weight: 600;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transition: all 0.2s;
}

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

.btn-danger {
  background: var(--danger);
}

.btn-danger:hover {
  background: #dc2626;
}

.btn-secondary {
  background: #253352;
  color: #cbd5e1;
}

.btn-secondary:hover {
  background: #33446b;
  color: #fff;
}

.btn-sm {
  padding: 5px 12px;
  font-size: 0.8rem;
}

/* Forms & Inputs */
.form-group {
  margin-bottom: 16px;
}

label {
  display: block;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-muted);
  margin-bottom: 6px;
}

input, select, textarea {
  width: 100%;
  background: #0b1120;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 10px 14px;
  color: var(--text-main);
  font-size: 0.92rem;
  outline: none;
  transition: border-color 0.2s;
}

input:focus, select:focus, textarea:focus {
  border-color: var(--primary);
}

/* Code Blocks */
pre, code {
  font-family: 'JetBrains Mono', Consolas, Monaco, monospace;
}

pre {
  background: #090e18;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 16px;
  overflow-x: auto;
  color: #93c5fd;
  font-size: 0.88rem;
  line-height: 1.5;
}

/* WebRTC Test Studio */
.studio-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: 24px;
}

.studio-video-container {
  position: relative;
  aspect-ratio: 16/9;
  background: #000;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: center;
}

.studio-video-container video {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.video-overlay-badge {
  position: absolute;
  top: 12px;
  left: 12px;
  background: rgba(0, 0, 0, 0.75);
  padding: 4px 10px;
  border-radius: 6px;
  font-size: 0.8rem;
  font-weight: 500;
}

/* Console Logs Box */
.console-box {
  background: #080d16;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 14px;
  height: 380px;
  overflow-y: auto;
  font-family: monospace;
  font-size: 0.84rem;
}

.log-entry {
  padding: 4px 0;
  border-bottom: 1px solid #141f33;
}

.log-time { color: var(--text-dim); margin-right: 8px; }
.log-info { color: #60a5fa; }
.log-warn { color: #fbbf24; }
.log-error { color: #f87171; }

/* Meter */
.meter-container {
  height: 8px;
  background: #1e293b;
  border-radius: 4px;
  overflow: hidden;
  margin-top: 8px;
}

.meter-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, #10b981, #f59e0b, #ef4444);
  transition: width 0.1s;
}
.log-call { color: #34d399; font-weight: 600; }