:root {
  /* Microchip Brand Palette */
  --microchip-red: #E21F26;
  --microchip-dark: #231F20;
  --bg-color: #0F1115;
  --card-bg: #1A1D23;
  --card-hover: #252A33;
  --text-primary: #FFFFFF;
  --text-secondary: #94A3B8;
  --accent-color: #3B82F6;
  --border-color: #2D333B;
  
  /* Spacing & Sizing */
  --radius-lg: 16px;
  --radius-md: 8px;
  --space-xs: 8px;
  --space-sm: 16px;
  --space-md: 24px;
  --space-lg: 40px;
  --space-xl: 64px;
  
  /* Typography */
  --font-main: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
}

* {
  box-sizing: border-box;
  -webkit-font-smoothing: antialiased;
}

body {
  margin: 0;
  padding: 0;
  font-family: var(--font-main);
  background-color: var(--bg-color);
  color: var(--text-primary);
  line-height: 1.5;
  overflow-x: hidden;
  min-height: 100vh;
}

.app-container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: var(--space-md);
}

/* Header */
header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-md) 0;
  margin-bottom: var(--space-lg);
  border-bottom: 1px solid var(--border-color);
}

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

.logo-placeholder {
  width: 40px;
  height: 40px;
  background-color: var(--microchip-red);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: bold;
  font-size: 20px;
}

.brand-name {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.app-version {
  font-size: 0.75rem;
  color: var(--text-secondary);
  background: var(--card-bg);
  padding: 4px 10px;
  border-radius: 100px;
  border: 1px solid var(--border-color);
}

/* Hero Section */
.hero {
  margin-bottom: var(--space-lg);
  text-align: center;
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 3rem);
  margin: 0 0 12px 0;
  font-weight: 800;
  background: linear-gradient(to right, #fff, #94A3B8);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero p {
  color: var(--text-secondary);
  font-size: 1.125rem;
  max-width: 600px;
  margin: 0 auto;
}

/* Tool Grid */
.tool-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--space-md);
  margin-top: var(--space-lg);
}

.tool-card {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: var(--space-md);
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  text-decoration: none;
  color: inherit;
  display: flex;
  flex-direction: column;
  position: relative;
  overflow: hidden;
}

.tool-card:hover {
  transform: translateY(-4px);
  border-color: var(--microchip-red);
  background: var(--card-hover);
  box-shadow: 0 10px 30px -10px rgba(226, 31, 38, 0.2);
}

.tool-icon-wrapper {
  width: 48px;
  height: 48px;
  background: rgba(226, 31, 38, 0.1);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--space-sm);
  color: var(--microchip-red);
}

.tool-card h3 {
  margin: 0 0 8px 0;
  font-size: 1.25rem;
  font-weight: 600;
}

.tool-card p {
  margin: 0;
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.4;
}

.card-arrow {
  position: absolute;
  top: 24px;
  right: 24px;
  opacity: 0;
  transform: translateX(-10px);
  transition: all 0.3s ease;
  color: var(--microchip-red);
}

.tool-card:hover .card-arrow {
  opacity: 1;
  transform: translateX(0);
}

/* Secondary Actions / Footer */
.action-bar {
  margin-top: var(--space-xl);
  display: flex;
  justify-content: center;
  gap: var(--space-md);
  flex-wrap: wrap;
}

.btn-secondary {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  padding: 12px 24px;
  border-radius: var(--radius-md);
  text-decoration: none;
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 8px;
  transition: all 0.2s ease;
}

.btn-secondary:hover {
  background: var(--border-color);
}

/* Device Detail View Styles */
.detail-layout {
  display: grid;
  grid-template-columns: 350px 1fr;
  gap: var(--space-md);
  height: calc(100vh - 160px);
}

.sidebar {
  background: var(--card-bg);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
}

.sidebar-header {
  padding: var(--space-sm);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.device-list {
  flex: 1;
  overflow-y: auto;
  padding: var(--space-sm);
}

.device-item {
  padding: 12px;
  border-radius: var(--radius-md);
  margin-bottom: 8px;
  cursor: pointer;
  border: 1px solid transparent;
  transition: 0.2s;
}

.device-item:hover {
  background: rgba(255, 255, 255, 0.05);
}

.device-item.active {
  background: rgba(59, 130, 246, 0.1);
  border-color: var(--accent-color);
}

.device-name {
  display: block;
  font-weight: 600;
  margin-bottom: 4px;
}

.device-meta {
  display: flex;
  justify-content: space-between;
  font-size: 0.75rem;
  color: var(--text-secondary);
}

.rssi-indicator {
  display: flex;
  gap: 2px;
  align-items: flex-end;
  height: 12px;
}

.rssi-bar {
  width: 3px;
  background: var(--border-color);
}

.rssi-bar.fill {
  background: var(--accent-color);
}

/* Terminal / Console area */
.main-content {
  background: var(--card-bg);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.content-header {
  padding: var(--space-sm) var(--space-md);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.terminal-area {
  flex: 1;
  background: #000;
  padding: var(--space-md);
  font-family: 'Courier New', Courier, monospace;
  overflow-y: auto;
}

.terminal-line {
  margin-bottom: 4px;
  font-size: 0.9rem;
}

.terminal-line.rx { color: #10B981; }
.terminal-line.tx { color: #3B82F6; }
.terminal-line.sys { color: #F59E0B; }

/* Utility Classes for UART page */
.flex-center { display: flex; align-items: center; gap: 12px; }
.flex-between { display: flex; justify-content: space-between; align-items: center; }
.btn-small { padding: 4px 12px; font-size: 0.8rem; }
.btn-danger { background: var(--microchip-red); border-color: var(--microchip-red); color: white; }
.btn-primary { background: var(--accent-color); border-color: var(--accent-color); color: white; }
.text-bold { font-weight: 600; }
.text-muted { font-size: 0.75rem; color: var(--text-secondary); }
.no-decoration { color: inherit; text-decoration: none; }

.input-area {
  padding: var(--space-sm);
  background: var(--card-bg);
  border-top: 1px solid var(--border-color);
  display: flex;
  gap: var(--space-sm);
}

.input-field {
  flex: 1;
  background: var(--bg-color);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  color: #fff;
  padding: 10px 16px;
  font-family: inherit;
}

.input-field:focus {
  outline: none;
  border-color: var(--accent-color);
}

.badge {
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 0.7rem;
  text-transform: uppercase;
  font-weight: 700;
}

.badge-blue { background: rgba(59, 130, 246, 0.2); color: #60A5FA; }
.badge-green { background: rgba(16, 185, 129, 0.2); color: #34D399; }

@media (max-width: 768px) {
  .detail-layout {
    grid-template-columns: 1fr;
  }
  .sidebar {
    display: none; /* In a real app we'd have a toggle or separate view */
  }
}