/* Reset and base styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  /* Color palette */
  --primary-color: #667eea;
  --primary-dark: #5568d3;
  --secondary-color: #764ba2;
  --text-dark: #333;
  --text-light: #666;
  --text-lighter: #999;
  --border-color: #e0e0e0;
  --bg-light: #f0f0f0;
  --success-color: #4caf50;
  --error-color: #f44336;
  --info-color: #2196f3;
  
  /* Spacing */
  --spacing-xs: 8px;
  --spacing-sm: 12px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;
  --spacing-xxl: 40px;
  
  /* Border radius */
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 12px;
  
  /* Shadows */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.12);
  --shadow-lg: 0 10px 40px rgba(0, 0, 0, 0.1);
  
  /* Typography */
  --font-size-xs: 12px;
  --font-size-sm: 14px;
  --font-size-base: 16px;
  --font-size-lg: 18px;
  --font-size-xl: 24px;
  --font-size-xxl: 28px;
  --font-size-xxxl: 32px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-lg);
  font-size: var(--font-size-base);
  line-height: 1.6;
}

#app {
  width: 100%;
  max-width: 500px;
  animation: fadeInScale 0.4s ease-out;
}

#app.fade-out {
  animation: fadeOutScale 0.3s ease-in;
}

/* Card styles */
.card {
  background: white;
  border-radius: var(--radius-lg);
  padding: var(--spacing-xxl);
  box-shadow: var(--shadow-lg);
  width: 100%;
}

.card h1 {
  font-size: var(--font-size-xxl);
  margin-bottom: var(--spacing-sm);
  color: var(--text-dark);
  font-weight: 700;
}

.card p {
  color: var(--text-light);
  margin-bottom: var(--spacing-xl);
  font-size: var(--font-size-base);
}

/* Form styles */
.form-group {
  margin-bottom: var(--spacing-lg);
}

.form-group label {
  display: block;
  margin-bottom: var(--spacing-xs);
  color: var(--text-dark);
  font-weight: 600;
  font-size: var(--font-size-sm);
}

.form-group input {
  width: 100%;
  padding: var(--spacing-md);
  border: 2px solid var(--border-color);
  border-radius: var(--radius-md);
  font-size: var(--font-size-base);
  transition: all 0.3s ease;
  font-family: inherit;
}

.form-group input:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

/* Button styles */
.btn {
  width: 100%;
  padding: var(--spacing-md) var(--spacing-lg);
  border: none;
  border-radius: var(--radius-md);
  font-size: var(--font-size-base);
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  font-family: inherit;
  text-align: center;
  min-height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.btn-primary {
  background: var(--primary-color);
  color: white;
}

.btn-primary:hover:not(:disabled) {
  background: var(--primary-dark);
  transform: translateY(-2px);
  box-shadow: 0 5px 15px rgba(102, 126, 234, 0.3);
}

.btn-primary:active:not(:disabled) {
  transform: translateY(0);
}

.btn-primary:disabled {
  background: #ccc;
  cursor: not-allowed;
  transform: none;
}

.btn-secondary {
  background: var(--bg-light);
  color: var(--text-dark);
  margin-top: var(--spacing-sm);
}

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

/* Dashboard styles */
.dashboard {
  text-align: center;
}

.dashboard h1 {
  margin-bottom: var(--spacing-sm);
  font-size: var(--font-size-xxl);
}

.dashboard .user-info {
  color: var(--text-light);
  margin-bottom: var(--spacing-xl);
  font-size: var(--font-size-sm);
  word-break: break-word;
}

.dashboard-buttons {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-lg);
}

.btn-large {
  padding: var(--spacing-lg) var(--spacing-md);
  font-size: var(--font-size-lg);
  background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
  color: white;
  border-radius: var(--radius-lg);
  min-height: 64px;
  font-weight: 700;
}

.btn-large:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 20px rgba(102, 126, 234, 0.4);
}

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

.btn-logout {
  background: transparent;
  color: var(--text-lighter);
  padding: var(--spacing-sm);
  font-size: var(--font-size-sm);
  min-height: auto;
}

.btn-logout:hover {
  color: var(--text-dark);
  background: #f5f5f5;
}

/* Section page styles */
.section-page {
  text-align: center;
}

.section-page h1 {
  margin-bottom: var(--spacing-lg);
  font-size: var(--font-size-xxl);
}

.section-page p {
  color: var(--text-light);
  margin-bottom: var(--spacing-xl);
  font-size: var(--font-size-base);
}

/* Toast styles */
#toast-container {
  position: fixed;
  top: var(--spacing-lg);
  right: var(--spacing-lg);
  z-index: 9999;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
  max-width: 400px;
}

.toast {
  background: white;
  padding: var(--spacing-md) var(--spacing-lg);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
  min-width: 280px;
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  animation: slideIn 0.3s ease;
}

.toast.success {
  border-left: 4px solid var(--success-color);
}

.toast.error {
  border-left: 4px solid var(--error-color);
}

.toast.info {
  border-left: 4px solid var(--info-color);
}

.toast-message {
  flex: 1;
  color: var(--text-dark);
  font-size: var(--font-size-sm);
  word-break: break-word;
}

@keyframes slideIn {
  from {
    transform: translateX(400px);
    opacity: 0;
  }
  to {
    transform: translateX(0);
    opacity: 1;
  }
}

@keyframes fadeInScale {
  from {
    opacity: 0;
    transform: scale(0.95);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

@keyframes fadeOutScale {
  from {
    opacity: 1;
    transform: scale(1);
  }
  to {
    opacity: 0;
    transform: scale(0.95);
  }
}

/* Error message styles */
.error-message {
  background: #fee;
  color: #c33;
  padding: var(--spacing-sm);
  border-radius: var(--radius-sm);
  margin-bottom: var(--spacing-lg);
  font-size: var(--font-size-sm);
}

/* Loading state */
.loading {
  opacity: 0.6;
  pointer-events: none;
}

/* ========================================
   RESPONSIVE DESIGN
   ======================================== */

/* Tablets and small laptops (768px - 1024px) */
@media (min-width: 768px) {
  #app {
    max-width: 600px;
  }
  
  .card {
    padding: 48px;
  }
  
  .card h1 {
    font-size: var(--font-size-xxxl);
  }
  
  .dashboard-buttons {
    gap: var(--spacing-lg);
  }
  
  .btn-large {
    font-size: var(--font-size-xl);
    padding: var(--spacing-xl) var(--spacing-lg);
    min-height: 72px;
  }
  
  .form-group input {
    padding: 15px var(--spacing-lg);
    font-size: var(--font-size-lg);
  }
  
  .btn {
    padding: 16px var(--spacing-xl);
    font-size: var(--font-size-lg);
  }
}

/* Desktop (1024px+) */
@media (min-width: 1024px) {
  body {
    padding: var(--spacing-xxl);
  }
  
  #app {
    max-width: 700px;
  }
  
  .card {
    padding: 56px;
  }
  
  .dashboard-buttons {
    flex-direction: row;
    gap: var(--spacing-xl);
  }
  
  .btn-large {
    flex: 1;
    min-height: 120px;
    font-size: var(--font-size-xl);
  }
  
  /* Hover effects more pronounced on desktop */
  .btn-large:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 28px rgba(102, 126, 234, 0.5);
  }
  
  .form-group input:hover {
    border-color: #c0c0c0;
  }
}

/* Mobile landscape orientation */
@media (max-height: 600px) and (orientation: landscape) {
  body {
    padding: var(--spacing-sm);
    align-items: flex-start;
    padding-top: var(--spacing-lg);
  }
  
  .card {
    padding: var(--spacing-lg);
    margin: var(--spacing-sm) auto;
  }
  
  .card h1 {
    font-size: var(--font-size-xl);
    margin-bottom: var(--spacing-xs);
  }
  
  .card p {
    margin-bottom: var(--spacing-md);
  }
  
  .form-group {
    margin-bottom: var(--spacing-md);
  }
  
  .btn-large {
    min-height: 50px;
    padding: var(--spacing-md);
  }
}

/* Small mobile devices (320px - 480px) */
@media (max-width: 480px) {
  body {
    padding: var(--spacing-md);
  }
  
  .card {
    padding: var(--spacing-lg);
    border-radius: var(--radius-md);
  }
  
  .card h1 {
    font-size: var(--font-size-xl);
  }
  
  .card p {
    font-size: var(--font-size-sm);
    margin-bottom: var(--spacing-lg);
  }
  
  .form-group input {
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: var(--font-size-base);
  }
  
  .btn {
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: var(--font-size-base);
  }
  
  .btn-large {
    font-size: var(--font-size-base);
    padding: var(--spacing-md);
    min-height: 56px;
  }
  
  .dashboard h1 {
    font-size: var(--font-size-xl);
  }
  
  .dashboard .user-info {
    font-size: var(--font-size-xs);
    margin-bottom: var(--spacing-lg);
  }
  
  /* Toast adjustments for small screens */
  #toast-container {
    top: var(--spacing-sm);
    right: var(--spacing-sm);
    left: var(--spacing-sm);
    max-width: none;
  }
  
  .toast {
    min-width: auto;
    width: 100%;
  }
}

/* Very small devices (< 360px) */
@media (max-width: 360px) {
  body {
    padding: var(--spacing-sm);
  }
  
  .card {
    padding: var(--spacing-md);
  }
  
  .card h1 {
    font-size: var(--font-size-lg);
  }
  
  .btn-large {
    font-size: var(--font-size-sm);
    min-height: 48px;
  }
}

/* Touch device optimizations */
@media (hover: none) and (pointer: coarse) {
  /* Larger touch targets for mobile */
  .btn {
    min-height: 48px;
  }
  
  .form-group input {
    min-height: 44px;
  }
  
  /* Remove hover effects on touch devices */
  .btn-primary:hover:not(:disabled) {
    transform: none;
    box-shadow: none;
  }
  
  .btn-large:hover {
    transform: none;
    box-shadow: none;
  }
  
  /* Active states instead */
  .btn-primary:active:not(:disabled) {
    background: var(--primary-dark);
  }
  
  .btn-large:active {
    opacity: 0.9;
  }
}

/* High DPI screens */
@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {
  .card {
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.15);
  }
}

/* Dark mode support (if needed in future) */
@media (prefers-color-scheme: dark) {
  /* Placeholder for dark mode styles */
}

/* Reduced motion for accessibility */
@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  
  .btn:hover,
  .btn-large:hover {
    transform: none;
  }
}