/* ========================================
   PetPulse Design System - Main Styles
   ======================================== */

/* CSS Custom Properties (Design Tokens) */
:root {
  /* Color Palette */
  --color-primary: #2A9D8F;
  --color-primary-light: #3DB5A5;
  --color-primary-dark: #1F7A6F;
  --color-secondary: #E76F51;
  --color-secondary-light: #F08A6F;
  --color-secondary-dark: #D15A3E;
  --color-background: #F4F1DE;
  --color-surface: #FFFFFF;
  --color-text: #264653;
  --color-text-light: #5A6C75;
  --color-text-muted: #8A9BA5;
  --color-border: #E0DDD0;
  --color-error: #E63946;
  --color-success: #06D6A0;
  --color-warning: #FFB703;
  
  /* Typography */
  --font-heading: 'Nunito', sans-serif;
  --font-body: 'Roboto', sans-serif;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 2rem;
  --font-size-4xl: 2.5rem;
  --font-weight-light: 300;
  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  --font-weight-extrabold: 800;
  --line-height-tight: 1.25;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.75;
  
  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  --spacing-3xl: 4rem;
  
  /* Border Radius */
  --radius-sm: 0.25rem;
  --radius-md: 0.5rem;
  --radius-lg: 1rem;
  --radius-xl: 1.5rem;
  --radius-full: 9999px;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07);
  --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.15);
  
  /* Transitions */
  --transition-fast: 150ms ease-in-out;
  --transition-base: 250ms ease-in-out;
  --transition-slow: 350ms ease-in-out;
  
  /* Z-index */
  --z-base: 1;
  --z-dropdown: 100;
  --z-sticky: 200;
  --z-fixed: 300;
  --z-modal: 400;
  --z-popover: 500;
  --z-tooltip: 600;
}

/* ========================================
   Reset & Base Styles
   ======================================== */

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

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-body);
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-normal);
  line-height: var(--line-height-normal);
  color: var(--color-text);
  background-color: var(--color-background);
  overflow-x: hidden;
}

/* ========================================
   Typography
   ======================================== */

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: var(--font-weight-bold);
  line-height: var(--line-height-tight);
  color: var(--color-text);
  margin-bottom: var(--spacing-md);
}

h1 {
  font-size: var(--font-size-4xl);
  font-weight: var(--font-weight-extrabold);
}

h2 {
  font-size: var(--font-size-3xl);
}

h3 {
  font-size: var(--font-size-2xl);
}

h4 {
  font-size: var(--font-size-xl);
}

h5 {
  font-size: var(--font-size-lg);
}

h6 {
  font-size: var(--font-size-base);
}

p {
  margin-bottom: var(--spacing-md);
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-primary-dark);
}

/* ========================================
   Layout
   ======================================== */

.app-container {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.main-content {
  flex: 1;
  padding: var(--spacing-lg);
  padding-bottom: calc(var(--spacing-3xl) + 56px); /* Account for FAB */
  max-width: 1200px;
  margin: 0 auto;
  width: 100%;
}

/* ========================================
   Loading Screen
   ======================================== */

.loading-screen {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 9999;
}

.loading-content {
  text-align: center;
  color: white;
}

.loading-logo {
  width: 120px;
  height: 120px;
  margin-bottom: var(--spacing-lg);
  animation: pulse 2s ease-in-out infinite;
}

.loading-spinner {
  width: 50px;
  height: 50px;
  border: 4px solid rgba(255, 255, 255, 0.3);
  border-top-color: white;
  border-radius: var(--radius-full);
  margin: var(--spacing-lg) auto;
  animation: spin 1s linear infinite;
}

.loading-screen p {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-medium);
  color: white;
  margin: 0;
}

/* ========================================
   Animations
   ======================================== */

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

@keyframes pulse {
  0%, 100% {
    transform: scale(1);
    opacity: 1;
  }
  50% {
    transform: scale(1.05);
    opacity: 0.9;
  }
}

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

@keyframes slideUp {
  from {
    transform: translateY(100%);
  }
  to {
    transform: translateY(0);
  }
}

@keyframes slideDown {
  from {
    transform: translateY(-100%);
  }
  to {
    transform: translateY(0);
  }
}

/* ========================================
   Utility Classes
   ======================================== */

/* Display */
.hidden {
  display: none !important;
}

.block {
  display: block;
}

.inline-block {
  display: inline-block;
}

.flex {
  display: flex;
}

.inline-flex {
  display: inline-flex;
}

.grid {
  display: grid;
}

/* Flex */
.flex-row {
  flex-direction: row;
}

.flex-col {
  flex-direction: column;
}

.items-center {
  align-items: center;
}

.items-start {
  align-items: flex-start;
}

.items-end {
  align-items: flex-end;
}

.justify-center {
  justify-content: center;
}

.justify-between {
  justify-content: space-between;
}

.justify-around {
  justify-content: space-around;
}

.gap-xs {
  gap: var(--spacing-xs);
}

.gap-sm {
  gap: var(--spacing-sm);
}

.gap-md {
  gap: var(--spacing-md);
}

.gap-lg {
  gap: var(--spacing-lg);
}

.gap-xl {
  gap: var(--spacing-xl);
}

/* Text Alignment */
.text-left {
  text-align: left;
}

.text-center {
  text-align: center;
}

.text-right {
  text-align: right;
}

/* Text Colors */
.text-primary {
  color: var(--color-primary);
}

.text-secondary {
  color: var(--color-secondary);
}

.text-muted {
  color: var(--color-text-muted);
}

.text-error {
  color: var(--color-error);
}

.text-success {
  color: var(--color-success);
}

/* Font Weights */
.font-light {
  font-weight: var(--font-weight-light);
}

.font-normal {
  font-weight: var(--font-weight-normal);
}

.font-medium {
  font-weight: var(--font-weight-medium);
}

.font-semibold {
  font-weight: var(--font-weight-semibold);
}

.font-bold {
  font-weight: var(--font-weight-bold);
}

/* Margins */
.m-0 {
  margin: 0;
}

.mt-sm {
  margin-top: var(--spacing-sm);
}

.mt-md {
  margin-top: var(--spacing-md);
}

.mt-lg {
  margin-top: var(--spacing-lg);
}

.mb-sm {
  margin-bottom: var(--spacing-sm);
}

.mb-md {
  margin-bottom: var(--spacing-md);
}

.mb-lg {
  margin-bottom: var(--spacing-lg);
}

/* Padding */
.p-0 {
  padding: 0;
}

.p-sm {
  padding: var(--spacing-sm);
}

.p-md {
  padding: var(--spacing-md);
}

.p-lg {
  padding: var(--spacing-lg);
}

/* Width */
.w-full {
  width: 100%;
}

.w-auto {
  width: auto;
}

/* ========================================
   Responsive Design
   ======================================== */

@media (max-width: 768px) {
  :root {
    --font-size-4xl: 2rem;
    --font-size-3xl: 1.75rem;
    --font-size-2xl: 1.375rem;
  }
  
  .main-content {
    padding: var(--spacing-md);
  }
  
  h1 {
    font-size: var(--font-size-3xl);
  }
  
  h2 {
    font-size: var(--font-size-2xl);
  }
}

@media (max-width: 480px) {
  .main-content {
    padding: var(--spacing-sm);
  }
}

/* ========================================
   Accessibility
   ======================================== */

.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;
}

/* Focus styles */
*:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}