:root {
  --space-black: #121212;
  --deep-blue: #0a192f;
  --neon-blue: #00d8ff;
  --neon-purple: #6e00ff;
  --tech-gray: #2d3748;
  --light-panel: #1e2b3a;
  --interactive-sim: #00ff00;
  --glow-effect: 0 0 10px rgba(0, 216, 255, 0.6);
  --grid-lines: rgba(0, 216, 255, 0.1);
}

* {
  color: #e6e6e6;
}

body {
  background: linear-gradient(135deg, var(--space-black), var(--deep-blue));
  color: #e6e6e6;
  font-family: "Titillium Web", "Segoe UI", sans-serif;
  position: relative;
}

/* Grid background for futuristic look */
body::before {
  content: "";
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image: linear-gradient(var(--grid-lines) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-lines) 1px, transparent 1px);
  background-size: 40px 40px;
  z-index: -1;
}

.navbar {
  background: var(--light-panel) !important;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.4);
  backdrop-filter: blur(5px);
  border-bottom: 1px solid var(--neon-blue);
}

.navbar-brand {
  color: var(--neon-blue) !important;
  font-weight: 600;
  letter-spacing: 1px;
  text-shadow: var(--glow-effect);
}

.btn-light {
  background: transparent;
  border: 1px solid var(--neon-blue);
  color: var(--neon-blue);
  transition: all 0.3s;
}

.btn-light:hover {
  background: var(--neon-blue);
  color: var(--deep-blue);
  box-shadow: var(--glow-effect);
}
.btn-light-g {
  background: transparent;
  border: 1px solid var(--interactive-sim);
  color: var(--interactive-sim);
  transition: all 0.3s;
}

.btn-light-g:hover {
  background: var(--interactive-sim);
  color: var(--deep-blue);
  box-shadow: var(--glow-effect);
}

.progress {
  background: var(--light-panel);
  height: 4px !important;
}

.progress-bar {
  background: linear-gradient(90deg, var(--neon-blue), var(--neon-purple));
  box-shadow: var(--glow-effect);
}

.slide {
  display: none;
  margin: 2rem 0;
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.5s, transform 0.5s;
}

.slide.active {
  display: block;
  opacity: 1;
  transform: translateY(0);
}

.card {
  background: var(--light-panel);
  border: none;
  border-radius: 15px;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
  backdrop-filter: blur(4px);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  border-left: 1px solid rgba(255, 255, 255, 0.1);
  overflow: hidden;
}

.card-title {
  color: var(--neon-blue);
  border-bottom: 1px solid var(--neon-blue);
  padding-bottom: 10px;
  margin-bottom: 20px;
}

.feature-card {
  padding: 1.5rem;
  background: rgba(30, 43, 58, 0.7);
  border-radius: 10px;
  transition: all 0.3s;
  border-left: 3px solid var(--neon-blue);
}

.feature-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--glow-effect);
  background: rgba(30, 43, 58, 0.9);
}

.feature-card h5 {
  color: var(--neon-blue);
}

.accordion-button {
  background: var(--tech-gray);
  color: var(--neon-blue);
  border-left: 3px solid var(--neon-blue);
}

.accordion-button:not(.collapsed) {
  background: var(--deep-blue);
  color: white;
}

.accordion-body {
  background: var(--light-panel);
  color: #e6e6e6;
}

.list-group-item {
  background: var(--tech-gray);
  color: #e6e6e6;
  border-color: var(--neon-blue);
}

.list-group-item a {
  color: var(--neon-blue);
  text-decoration: none;
}

.list-group-item a:hover {
  text-shadow: var(--glow-effect);
}

/* Animation for IoT elements */
@keyframes pulse {
  0% {
    opacity: 0.7;
  }
  50% {
    opacity: 1;
  }
  100% {
    opacity: 0.7;
  }
}

.iot-element {
  animation: pulse 2s infinite;
}

/* Simulation page specific styles */
.simulation-container {
  background: rgba(10, 25, 47, 0.8);
  border-radius: 15px;
  padding: 20px;
  margin-top: 20px;
  border: 1px solid var(--neon-blue);
  box-shadow: inset 0 0 20px rgba(0, 216, 255, 0.2);
}

.sim-controls {
  background: var(--tech-gray);
  border-radius: 10px;
  padding: 15px;
  margin-bottom: 20px;
}

.video-container {
  position: relative;
  padding-bottom: 56.25%; /* 16:9 aspect ratio */
  height: 0;
  overflow: hidden;
  border-radius: 10px;
  border: 1px solid var(--neon-purple);
}

.video-container iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

/* Data visualization placeholders */
.data-viz {
  height: 300px;
  background: linear-gradient(
    180deg,
    rgba(0, 216, 255, 0.05),
    rgba(110, 0, 255, 0.05)
  );
  border-radius: 10px;
  border: 1px dashed var(--neon-blue);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--neon-blue);
  margin-bottom: 20px;
}

h5 {
  color: #e6e6e6;
}