/* ==========================================================================
   ALPHA SQUARED - IoT Smart Health & Emergency Detection System
   Core Style Sheet & Design Tokens
   ========================================================================== */

:root {
  /* Color Palette - Dark Navy/Charcoal & Healthcare Accents */
  --bg-dark: #0b1120;
  --bg-card: #151d30;
  --bg-card-hover: #1c2742;
  --bg-glass: rgba(21, 29, 48, 0.85);
  
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;

  --accent-cyan: #06b6d4;
  --accent-blue: #3b82f6;
  --accent-blue-glow: rgba(59, 130, 246, 0.3);

  /* Health Status Indicators */
  --status-safe: #10b981;        /* Green */
  --status-safe-bg: rgba(16, 185, 129, 0.15);
  --status-warning: #f59e0b;     /* Yellow/Orange */
  --status-warning-bg: rgba(245, 158, 11, 0.15);
  --status-emergency: #ef4444;   /* Bright Red */
  --status-emergency-bg: rgba(239, 68, 68, 0.2);

  --border-color: #243049;
  --border-light: #334155;

  --font-main: 'Segoe UI', system-ui, -apple-system, BlinkMacSystemFont, Roboto, sans-serif;

  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 18px;

  --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  --shadow-card: 0 10px 25px -5px rgba(0, 0, 0, 0.4), 0 8px 10px -6px rgba(0, 0, 0, 0.3);
  --shadow-emergency: 0 0 30px rgba(239, 68, 68, 0.6);
}

/* Reset & Global Settings */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html, body {
  width: 100%;
  min-height: 100vh;
  background-color: var(--bg-dark);
  color: var(--text-primary);
  font-family: var(--font-main);
  line-height: 1.5;
  overflow-x: hidden;
}

a {
  color: var(--accent-cyan);
  text-decoration: none;
  transition: var(--transition);
}

a:hover {
  color: var(--accent-blue);
}

/* Header Navigation Bar */
.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 2rem;
  background: var(--bg-glass);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.brand-container {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.brand-logo {
  width: 38px;
  height: 38px;
  background: linear-gradient(135deg, var(--accent-cyan), var(--accent-blue));
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 1.2rem;
  color: #fff;
  box-shadow: 0 0 12px var(--accent-blue-glow);
}

.brand-title {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: 0.5px;
  background: linear-gradient(90deg, #ffffff, var(--accent-cyan));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 1.5rem;
  align-items: center;
}

.nav-link {
  color: var(--text-secondary);
  font-weight: 500;
  padding: 0.5rem 0.85rem;
  border-radius: var(--radius-sm);
  transition: var(--transition);
}

.nav-link:hover, .nav-link.active {
  color: var(--text-primary);
  background: rgba(255, 255, 255, 0.06);
}

.nav-link.active {
  border-bottom: 2px solid var(--accent-cyan);
}

/* Status Indicator Badges */
.mode-badge {
  padding: 0.35rem 0.85rem;
  border-radius: 50px;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.5px;
  text-transform: uppercase;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}

.mode-badge.live {
  background: var(--status-safe-bg);
  color: var(--status-safe);
  border: 1px solid var(--status-safe);
}

.mode-badge.demo {
  background: var(--status-warning-bg);
  color: var(--status-warning);
  border: 1px solid var(--status-warning);
}

.pulse-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: currentColor;
  animation: pulse 1.8s infinite;
}

@keyframes pulse {
  0% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.4; transform: scale(1.3); }
  100% { opacity: 1; transform: scale(1); }
}

/* UI Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.7rem 1.4rem;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--radius-sm);
  border: none;
  cursor: pointer;
  transition: var(--transition);
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent-cyan), var(--accent-blue));
  color: #ffffff;
  box-shadow: 0 4px 15px var(--accent-blue-glow);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(6, 182, 212, 0.5);
}

.btn-danger {
  background: var(--status-emergency);
  color: #ffffff;
}

.btn-danger:hover {
  background: #dc2626;
  box-shadow: 0 0 15px rgba(239, 68, 68, 0.5);
}

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

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

/* General Layout Containers */
.container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 1.5rem;
}

/* Cards */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  box-shadow: var(--shadow-card);
  transition: var(--transition);
}

.card:hover {
  border-color: var(--border-light);
}

.card-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 0.75rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

/* Emergency Alert Overlay Banner */
.emergency-banner {
  display: none;
  background: linear-gradient(90deg, #7f1d1d, #ef4444);
  color: #ffffff;
  padding: 1rem 1.5rem;
  font-weight: 700;
  align-items: center;
  justify-content: space-between;
  border-bottom: 2px solid #f87171;
  animation: flashEmergency 1.2s infinite alternate;
}

.emergency-banner.active {
  display: flex;
}

@keyframes flashEmergency {
  from { background-color: #991b1b; }
  to { background-color: #ef4444; }
}

/* ==========================================================================
   Professional Form Components & Inputs
   ========================================================================== */
.form-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  margin-bottom: 0.85rem;
}

.form-group label {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: 0.35rem;
  letter-spacing: 0.2px;
}

.form-group .label-desc {
  font-size: 0.75rem;
  color: var(--text-muted);
  font-weight: 400;
}

.form-input,
.form-select {
  width: 100%;
  height: 42px;
  padding: 0.55rem 0.85rem;
  font-family: inherit;
  font-size: 0.9rem;
  color: var(--text-primary);
  background-color: rgba(11, 17, 32, 0.75);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  outline: none;
  transition: var(--transition);
  -webkit-appearance: none;
  appearance: none;
}

.form-input::placeholder {
  color: var(--text-muted);
  opacity: 0.7;
}

.form-input:hover,
.form-select:hover {
  border-color: var(--border-light);
}

.form-input:focus,
.form-select:focus {
  border-color: var(--accent-cyan);
  box-shadow: 0 0 0 3px rgba(6, 182, 212, 0.2);
  background-color: rgba(15, 23, 42, 0.95);
}

.form-input:disabled,
.form-select:disabled {
  background-color: rgba(30, 41, 59, 0.4);
  color: var(--text-muted);
  cursor: not-allowed;
  border-color: var(--border-color);
}

.input-with-button {
  display: flex;
  gap: 0.5rem;
  align-items: center;
}

.input-with-button .form-input {
  flex: 1;
}

/* Custom Toggle Switch */
.switch-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem 1rem;
  background: rgba(11, 17, 32, 0.6);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  margin-bottom: 0.85rem;
}

.switch-label {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}

.switch-title {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-primary);
}

.switch-subtitle {
  font-size: 0.75rem;
  color: var(--text-muted);
}

.toggle-switch {
  position: relative;
  display: inline-block;
  width: 46px;
  height: 24px;
  flex-shrink: 0;
}

.toggle-switch input {
  opacity: 0;
  width: 0;
  height: 0;
}

.toggle-slider {
  position: absolute;
  cursor: pointer;
  top: 0; left: 0; right: 0; bottom: 0;
  background-color: #334155;
  transition: 0.25s;
  border-radius: 24px;
}

.toggle-slider:before {
  position: absolute;
  content: "";
  height: 18px;
  width: 18px;
  left: 3px;
  bottom: 3px;
  background-color: white;
  transition: 0.25s;
  border-radius: 50%;
}

.toggle-switch input:checked + .toggle-slider {
  background-color: var(--status-safe);
}

.toggle-switch input:checked + .toggle-slider:before {
  transform: translateX(22px);
}

.toggle-switch input:focus + .toggle-slider {
  box-shadow: 0 0 0 2px var(--accent-cyan);
}

/* Inline feedback messages */
.feedback-msg {
  display: none;
  padding: 0.65rem 0.9rem;
  border-radius: var(--radius-sm);
  font-size: 0.82rem;
  font-weight: 500;
  margin-top: 0.5rem;
  align-items: center;
  gap: 0.5rem;
}

.feedback-msg.show {
  display: flex;
}

.feedback-msg.success {
  background: var(--status-safe-bg);
  border: 1px solid rgba(16, 185, 129, 0.35);
  color: #34d399;
}

.feedback-msg.error {
  background: var(--status-emergency-bg);
  border: 1px solid rgba(239, 68, 68, 0.35);
  color: #f87171;
}

.feedback-msg.info {
  background: rgba(14, 165, 233, 0.1);
  border: 1px solid rgba(14, 165, 233, 0.35);
  color: var(--accent-cyan);
}

/* Footer */
.footer {
  text-align: center;
  padding: 2rem;
  color: var(--text-muted);
  font-size: 0.85rem;
  border-top: 1px solid var(--border-color);
  margin-top: 3rem;
}