:root {
  /* Color Palette - Premium Modern */
  --primary: #2563eb; /* Vibrant Blue */
  --primary-hover: #1d4ed8;
  --secondary: #10b981; /* Success Green */
  --background: #f8fafc; /* Light Mode Background */
  --surface: #ffffff; /* Light Mode Surface */
  --text-main: #0f172a; /* Slate 900 */
  --text-muted: #64748b; /* Slate 500 */
  --border: #e2e8f0;
  --error: #ef4444;

  /* High Contrast / Dark Mode equivalents */
  --hc-background: #0b0f19;
  --hc-surface: #1e293b;
  --hc-text: #f8fafc;
  --hc-text-muted: #94a3b8;
  --hc-border: #334155;

  /* Typography */
  --font-sans: 'Inter', sans-serif;

  /* Metrics */
  --radius-lg: 16px;
  --radius-md: 12px;
  --radius-sm: 8px;
  --shadow-subtle: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
  --shadow-hover: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

/* High Contrast Mode Class */
body.high-contrast {
  --background: var(--hc-background);
  --surface: var(--hc-surface);
  --text-main: var(--hc-text);
  --text-muted: var(--hc-text-muted);
  --border: var(--hc-border);
}

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

body {
  font-family: var(--font-sans);
  background-color: var(--background);
  color: var(--text-main);
  line-height: 1.6;
  transition: var(--transition);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Accessibility: Focus Styles */
*:focus-visible {
  outline: 3px solid var(--primary);
  outline-offset: 2px;
}

/* Utilities */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}

.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--primary);
  color: white;
  padding: 8px 16px;
  z-index: 100;
  transition: top 0.2s;
  text-decoration: none;
  font-weight: 600;
}
.skip-link:focus {
  top: 0;
}

/* Header */
.app-header {
  background-color: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 1rem 0;
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(10px);
  background-color: color-mix(in srgb, var(--surface) 90%, transparent);
}

.header-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

#app-title {
  font-size: 1.5rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--primary), #8b5cf6);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  letter-spacing: -0.5px;
}

.header-controls {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.btn-icon {
  background: transparent;
  border: none;
  color: var(--text-main);
  cursor: pointer;
  padding: 0.5rem;
  border-radius: var(--radius-sm);
  transition: var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
}

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

.tts-toggle[aria-pressed='true'] {
  color: var(--primary);
  background-color: color-mix(in srgb, var(--primary) 15%, transparent);
}

select {
  padding: 0.5rem 2rem 0.5rem 1rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  background-color: var(--surface);
  color: var(--text-main);
  font-family: var(--font-sans);
  font-size: 0.9rem;
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%2364748B' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 0.75rem center;
}

/* Layout Container */
.container {
  max-width: 1200px;
  margin: 2rem auto;
  padding: 0 1.5rem;
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
  flex: 1;
}

@media (min-width: 768px) {
  .container {
    grid-template-columns: 1fr 2fr;
  }
}

/* Cards */
.card {
  background-color: var(--surface);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-subtle);
  border: 1px solid var(--border);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: var(--transition);
}

.card:hover {
  box-shadow: var(--shadow-hover);
}

.card-header {
  padding: 1.25rem 1.5rem;
  border-bottom: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.card-header h2 {
  font-size: 1.125rem;
  font-weight: 600;
}

/* Crowd Dashboard */
.crowd-grid {
  padding: 1.5rem;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 1rem;
}

.gate-card {
  background-color: var(--background);
  padding: 1rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  text-align: center;
}

.gate-card h3 {
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-bottom: 0.5rem;
}

.crowd-level {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 0.25rem;
}

.wait-time {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.level-low {
  color: var(--secondary);
}
.level-medium {
  color: #f59e0b;
}
.level-high {
  color: var(--error);
}

.loading-state {
  grid-column: 1 / -1;
  text-align: center;
  padding: 2rem;
  color: var(--text-muted);
  font-style: italic;
}

/* Chat Interface */
.chat-interface {
  height: 600px;
}

.chat-history {
  flex: 1;
  overflow-y: auto;
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  scroll-behavior: smooth;
}

.message {
  max-width: 80%;
  padding: 1rem;
  border-radius: var(--radius-md);
  font-size: 0.95rem;
  animation: fadeIn 0.3s ease-out;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.system-msg {
  background-color: color-mix(in srgb, var(--primary) 10%, transparent);
  color: var(--text-main);
  align-self: flex-start;
  border-bottom-left-radius: 4px;
}

.user-msg {
  background-color: var(--primary);
  color: white;
  align-self: flex-end;
  border-bottom-right-radius: 4px;
}

.loading-msg {
  align-self: flex-start;
  color: var(--text-muted);
  display: flex;
  gap: 0.25rem;
}

.dot {
  width: 6px;
  height: 6px;
  background-color: var(--text-muted);
  border-radius: 50%;
  animation: bounce 1.4s infinite ease-in-out both;
}

.dot:nth-child(1) {
  animation-delay: -0.32s;
}
.dot:nth-child(2) {
  animation-delay: -0.16s;
}

@keyframes bounce {
  0%,
  80%,
  100% {
    transform: scale(0);
  }
  40% {
    transform: scale(1);
  }
}

.chat-form {
  padding: 1rem 1.5rem;
  border-top: 1px solid var(--border);
  display: flex;
  gap: 0.5rem;
  background-color: var(--surface);
}

.chat-form input {
  flex: 1;
  padding: 0.75rem 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background-color: var(--background);
  color: var(--text-main);
  font-family: var(--font-sans);
  font-size: 1rem;
  transition: var(--transition);
}

.chat-form input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--primary) 20%, transparent);
}

.btn-submit {
  background-color: var(--primary);
  color: white;
  border: none;
  border-radius: var(--radius-md);
  padding: 0 1rem;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
}

.btn-submit:hover {
  background-color: var(--primary-hover);
  transform: translateY(-1px);
}

.btn-submit:active {
  transform: translateY(1px);
}

.btn-submit:disabled {
  opacity: 0.7;
  cursor: not-allowed;
}

/* Footer */
.app-footer {
  text-align: center;
  padding: 2rem;
  color: var(--text-muted);
  font-size: 0.875rem;
  margin-top: auto;
}