:root {
  /* Mobile App Palette */
  --app-bg-top: #0f172a;
  --app-bg-bottom: #1e293b;
  --glass-white: rgba(255, 255, 255, 0.1);
  --glass-border: rgba(255, 255, 255, 0.2);
  --glass-shadow: rgba(0, 0, 0, 0.2);
  --primary-gradient-start: #7c3aed;
  --primary-gradient-end: #22d3ee;
  --primary-glow: rgba(34, 211, 238, 0.3);
  --text-primary: #f8fafc;
  --text-secondary: #cbd5e1;
  --text-disabled: #94a3b8;
  --success-green: #22c55e;
  --danger-red: #ef4444;
  --warn-gold: #fbbf24;

  /* Font */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: var(--font-family);
  background: linear-gradient(180deg, var(--app-bg-top) 0%, var(--app-bg-bottom) 100%);
  color: var(--text-primary);
  min-height: 100vh;
  overflow-x: hidden;
  line-height: 1.5;
}

/* Glassmorphism Classes */
.glass-card {
  background: var(--glass-white);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--glass-border);
  border-radius: 24px;
  box-shadow: 0 8px 32px 0 var(--glass-shadow);
}

.glass-nav {
  background: rgba(15, 23, 42, 0.8);
  backdrop-filter: blur(20px);
  border-top: 1px solid var(--glass-border);
}

/* Button Styles */
.primary-btn {
  background: linear-gradient(90deg, var(--primary-gradient-start) 0%, var(--primary-gradient-end) 100%);
  color: white;
  border: none;
  border-radius: 16px;
  padding: 16px 24px;
  font-weight: 600;
  font-size: 16px;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
  width: 100%;
  box-shadow: 0 4px 15px var(--primary-glow);
}

.primary-btn:active {
  transform: scale(0.98);
}

.primary-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* Input Styles */
.glass-input {
  background: var(--glass-white);
  border: 1px solid var(--glass-border);
  border-radius: 16px;
  padding: 16px;
  color: var(--text-primary);
  width: 100%;
  font-size: 16px;
  outline: none;
  transition: border-color 0.2s;
}

.glass-input:focus {
  border-color: var(--primary-gradient-end);
}

/* Typography */
h1 { font-size: 32px; font-weight: 700; margin-bottom: 8px; }
h2 { font-size: 24px; font-weight: 600; margin-bottom: 8px; }
p { color: var(--text-secondary); font-size: 14px; }

/* Layout Utilities */
.container {
  max-width: 500px;
  margin: 0 auto;
  padding: 24px;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

@media (min-width: 768px) {
  .container {
    max-width: 800px;
  }
}

.spacer { flex-grow: 1; }

/* Base Screen States */
.screen {
  display: none;
}

.screen.active {
  display: flex;
  flex-direction: column;
  animation: fadeIn 0.4s ease-out;
}

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