/* ===========================================
   ShelfLife Design System
   =========================================== */

/* ----------------- Tokens ----------------- */
:root {
  /* Colors - Sustainability/Fresh Food Palette */
  --color-primary: #10B981;        /* Emerald - fresh, eco */
  --color-primary-dark: #059669;
  --color-primary-light: #34D399;
  --color-secondary: #0D9488;      /* Teal - calm, organized */
  --color-secondary-light: #14B8A6;
  
  /* Status Colors */
  --color-fresh: #22C55E;          /* Green - good to go */
  --color-expiring-soon: #F59E0B;  /* Amber - use soon */
  --color-expired: #EF4444;        /* Red - expired */
  --color-frozen: #3B82F6;         /* Blue - frozen items */
  
  /* Neutrals */
  --color-bg: #F0FDF4;             /* Mint white */
  --color-surface: #FFFFFF;
  --color-surface-hover: #ECFDF5;
  --color-text: #064E3B;           /* Dark emerald */
  --color-text-secondary: #047857;
  --color-text-muted: #6B7280;
  --color-border: #D1FAE5;
  --color-border-strong: #A7F3D0;
  
  /* CTA */
  --color-cta: #F97316;            /* Orange - urgency, action */
  --color-cta-hover: #EA580C;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
  --shadow-card: 0 2px 8px rgba(16, 185, 129, 0.08);
  
  /* Spacing Scale */
  --space-1: 0.25rem;   /* 4px */
  --space-2: 0.5rem;    /* 8px */
  --space-3: 0.75rem;   /* 12px */
  --space-4: 1rem;      /* 16px */
  --space-5: 1.25rem;   /* 20px */
  --space-6: 1.5rem;    /* 24px */
  --space-8: 2rem;      /* 32px */
  --space-10: 2.5rem;   /* 40px */
  --space-12: 3rem;     /* 48px */
  
  /* Typography */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-size-xs: 0.75rem;    /* 12px */
  --font-size-sm: 0.875rem;   /* 14px */
  --font-size-base: 1rem;     /* 16px */
  --font-size-lg: 1.125rem;   /* 18px */
  --font-size-xl: 1.25rem;    /* 20px */
  --font-size-2xl: 1.5rem;    /* 24px */
  --font-size-3xl: 1.875rem;  /* 30px */
  
  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  
  --line-height-tight: 1.25;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.625;
  
  /* Border Radius */
  --radius-sm: 0.375rem;   /* 6px */
  --radius-md: 0.5rem;     /* 8px */
  --radius-lg: 0.75rem;    /* 12px */
  --radius-xl: 1rem;       /* 16px */
  --radius-full: 9999px;
  
  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 200ms ease;
  --transition-slow: 300ms ease;
}

/* ----------------- Reset & Base ----------------- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  line-height: var(--line-height-normal);
  color: var(--color-text);
  background: var(--color-bg);
  min-height: 100vh;
}

/* ----------------- App Shell ----------------- */
.app {
  max-width: 480px;
  margin: 0 auto;
  min-height: 100vh;
  background: var(--color-bg);
  position: relative;
  padding-bottom: 80px;
}

/* Header */
.header {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
  color: white;
  padding: var(--space-6) var(--space-4);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header__top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--space-4);
}

.header__logo {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-bold);
}

.header__logo-icon {
  font-size: var(--font-size-2xl);
}

.header__actions {
  display: flex;
  gap: var(--space-2);
}

.icon-btn {
  background: rgba(255, 255, 255, 0.2);
  border: none;
  border-radius: var(--radius-full);
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: background var(--transition-fast);
  color: white;
  font-size: var(--font-size-lg);
}

.icon-btn:hover {
  background: rgba(255, 255, 255, 0.3);
}

.icon-btn:focus {
  outline: 2px solid white;
  outline-offset: 2px;
}

/* Stats Row */
.stats-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-3);
}

.stat-card {
  background: rgba(255, 255, 255, 0.15);
  backdrop-filter: blur(10px);
  border-radius: var(--radius-lg);
  padding: var(--space-3);
  text-align: center;
}

.stat-card__value {
  font-size: var(--font-size-2xl);
  font-weight: var(--font-weight-bold);
  display: block;
}

.stat-card__label {
  font-size: var(--font-size-xs);
  opacity: 0.9;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

/* ----------------- Filter Tabs ----------------- */
.filter-tabs {
  display: flex;
  gap: var(--space-2);
  padding: var(--space-4);
  overflow-x: auto;
  scrollbar-width: none;
  -ms-overflow-style: none;
}

.filter-tabs::-webkit-scrollbar {
  display: none;
}

.filter-tab {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  padding: var(--space-2) var(--space-4);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-text-secondary);
  cursor: pointer;
  white-space: nowrap;
  transition: all var(--transition-fast);
}

.filter-tab:hover {
  background: var(--color-surface-hover);
  border-color: var(--color-primary);
}

.filter-tab:focus {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.filter-tab--active {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: white;
}

.filter-tab__count {
  background: rgba(0, 0, 0, 0.1);
  border-radius: var(--radius-full);
  padding: 2px 8px;
  margin-left: var(--space-1);
  font-size: var(--font-size-xs);
}

.filter-tab--active .filter-tab__count {
  background: rgba(255, 255, 255, 0.2);
}

/* ----------------- Section ----------------- */
.section {
  padding: 0 var(--space-4);
  margin-bottom: var(--space-6);
}

.section__header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--space-3);
}

.section__title {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text);
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.section__title-icon {
  font-size: var(--font-size-xl);
}

.section__link {
  font-size: var(--font-size-sm);
  color: var(--color-primary);
  text-decoration: none;
  font-weight: var(--font-weight-medium);
}

.section__link:hover {
  text-decoration: underline;
}

/* ----------------- Item Cards ----------------- */
.items-grid {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.item-card {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
  box-shadow: var(--shadow-card);
  display: flex;
  align-items: center;
  gap: var(--space-4);
  transition: all var(--transition-fast);
  border-left: 4px solid transparent;
  cursor: pointer;
}

.item-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

.item-card:focus-within {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.item-card--fresh {
  border-left-color: var(--color-fresh);
}

.item-card--expiring {
  border-left-color: var(--color-expiring-soon);
  background: linear-gradient(90deg, #FFFBEB 0%, var(--color-surface) 20%);
}

.item-card--expired {
  border-left-color: var(--color-expired);
  background: linear-gradient(90deg, #FEF2F2 0%, var(--color-surface) 20%);
  opacity: 0.8;
}

.item-card--frozen {
  border-left-color: var(--color-frozen);
}

.item-card__emoji {
  font-size: 2.5rem;
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-surface-hover);
  border-radius: var(--radius-md);
  flex-shrink: 0;
}

.item-card__content {
  flex: 1;
  min-width: 0;
}

.item-card__name {
  font-weight: var(--font-weight-semibold);
  font-size: var(--font-size-base);
  margin-bottom: var(--space-1);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.item-card__meta {
  display: flex;
  gap: var(--space-3);
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
}

.item-card__location {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

.item-card__status {
  text-align: right;
  flex-shrink: 0;
}

.item-card__days {
  font-weight: var(--font-weight-bold);
  font-size: var(--font-size-lg);
  display: block;
}

.item-card__days--fresh {
  color: var(--color-fresh);
}

.item-card__days--expiring {
  color: var(--color-expiring-soon);
}

.item-card__days--expired {
  color: var(--color-expired);
}

.item-card__days-label {
  font-size: var(--font-size-xs);
  color: var(--color-text-muted);
}

/* ----------------- Alert Banner ----------------- */
.alert-banner {
  background: linear-gradient(90deg, #FEF3C7 0%, #FEF9C3 100%);
  border: 1px solid #FCD34D;
  border-radius: var(--radius-lg);
  padding: var(--space-4);
  margin: var(--space-4);
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
}

.alert-banner__icon {
  font-size: var(--font-size-2xl);
  flex-shrink: 0;
}

.alert-banner__content {
  flex: 1;
}

.alert-banner__title {
  font-weight: var(--font-weight-semibold);
  color: #92400E;
  margin-bottom: var(--space-1);
}

.alert-banner__text {
  font-size: var(--font-size-sm);
  color: #A16207;
}

.alert-banner__action {
  background: #F59E0B;
  color: white;
  border: none;
  border-radius: var(--radius-md);
  padding: var(--space-2) var(--space-4);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  cursor: pointer;
  margin-top: var(--space-2);
  transition: background var(--transition-fast);
}

.alert-banner__action:hover {
  background: #D97706;
}

/* ----------------- Recipe Card ----------------- */
.recipe-card {
  background: var(--color-surface);
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-card);
}

.recipe-card__image {
  width: 100%;
  height: 160px;
  object-fit: cover;
  background: linear-gradient(135deg, #A7F3D0 0%, #6EE7B7 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 4rem;
}

.recipe-card__body {
  padding: var(--space-4);
}

.recipe-card__tag {
  background: var(--color-expiring-soon);
  color: white;
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-semibold);
  padding: var(--space-1) var(--space-2);
  border-radius: var(--radius-sm);
  display: inline-block;
  margin-bottom: var(--space-2);
}

.recipe-card__title {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  margin-bottom: var(--space-2);
}

.recipe-card__ingredients {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--space-3);
}

.recipe-card__footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.recipe-card__time {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
}

.recipe-card__btn {
  background: var(--color-primary);
  color: white;
  border: none;
  border-radius: var(--radius-md);
  padding: var(--space-2) var(--space-4);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  cursor: pointer;
  transition: background var(--transition-fast);
}

.recipe-card__btn:hover {
  background: var(--color-primary-dark);
}

/* ----------------- FAB (Floating Action Button) ----------------- */
.fab {
  position: fixed;
  bottom: 100px;
  right: calc(50% - 240px + 24px);
  width: 60px;
  height: 60px;
  background: var(--color-cta);
  color: white;
  border: none;
  border-radius: var(--radius-full);
  font-size: var(--font-size-2xl);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: var(--shadow-lg);
  transition: all var(--transition-fast);
  z-index: 90;
}

.fab:hover {
  background: var(--color-cta-hover);
  transform: scale(1.05);
}

.fab:focus {
  outline: 2px solid var(--color-cta);
  outline-offset: 4px;
}

@media (max-width: 480px) {
  .fab {
    right: 24px;
  }
}

/* ----------------- Bottom Nav ----------------- */
.bottom-nav {
  position: fixed;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 100%;
  max-width: 480px;
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  display: flex;
  justify-content: space-around;
  padding: var(--space-2) 0;
  z-index: 100;
}

.nav-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-2) var(--space-4);
  color: var(--color-text-muted);
  text-decoration: none;
  font-size: var(--font-size-xs);
  transition: color var(--transition-fast);
  border: none;
  background: none;
  cursor: pointer;
}

.nav-item:hover,
.nav-item--active {
  color: var(--color-primary);
}

.nav-item__icon {
  font-size: var(--font-size-xl);
}

/* ----------------- Empty State ----------------- */
.empty-state {
  text-align: center;
  padding: var(--space-12) var(--space-6);
}

.empty-state__icon {
  font-size: 4rem;
  margin-bottom: var(--space-4);
  opacity: 0.5;
}

.empty-state__title {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  margin-bottom: var(--space-2);
  color: var(--color-text);
}

.empty-state__text {
  color: var(--color-text-muted);
  margin-bottom: var(--space-6);
}

.empty-state__btn {
  background: var(--color-primary);
  color: white;
  border: none;
  border-radius: var(--radius-lg);
  padding: var(--space-3) var(--space-6);
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-medium);
  cursor: pointer;
  transition: background var(--transition-fast);
}

.empty-state__btn:hover {
  background: var(--color-primary-dark);
}

/* ----------------- Modal ----------------- */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  display: flex;
  align-items: flex-end;
  justify-content: center;
  z-index: 200;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-base);
}

.modal-overlay--visible {
  opacity: 1;
  visibility: visible;
}

.modal {
  background: var(--color-surface);
  border-radius: var(--radius-xl) var(--radius-xl) 0 0;
  width: 100%;
  max-width: 480px;
  max-height: 90vh;
  overflow-y: auto;
  transform: translateY(100%);
  transition: transform var(--transition-slow);
}

.modal-overlay--visible .modal {
  transform: translateY(0);
}

.modal__header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-4) var(--space-6);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  background: var(--color-surface);
}

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

.modal__close {
  background: none;
  border: none;
  font-size: var(--font-size-xl);
  color: var(--color-text-muted);
  cursor: pointer;
  padding: var(--space-2);
}

.modal__body {
  padding: var(--space-6);
}

/* Form Elements */
.form-group {
  margin-bottom: var(--space-5);
}

.form-label {
  display: block;
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-text);
  margin-bottom: var(--space-2);
}

.form-input {
  width: 100%;
  padding: var(--space-3) var(--space-4);
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-md);
  font-size: var(--font-size-base);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.1);
}

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

.form-select {
  width: 100%;
  padding: var(--space-3) var(--space-4);
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-md);
  font-size: var(--font-size-base);
  background: var(--color-surface);
  cursor: pointer;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-4);
}

.btn-primary {
  width: 100%;
  background: var(--color-primary);
  color: white;
  border: none;
  border-radius: var(--radius-lg);
  padding: var(--space-4);
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-semibold);
  cursor: pointer;
  transition: background var(--transition-fast);
}

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

.btn-primary:focus {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* Quick add buttons */
.quick-add {
  display: flex;
  gap: var(--space-2);
  margin-bottom: var(--space-5);
}

.quick-add__btn {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-4);
  background: var(--color-surface-hover);
  border: 1px dashed var(--color-border-strong);
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.quick-add__btn:hover {
  background: var(--color-border);
  border-color: var(--color-primary);
}

.quick-add__icon {
  font-size: var(--font-size-2xl);
}

.quick-add__text {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
}

/* ----------------- Loading State ----------------- */
.skeleton {
  background: linear-gradient(90deg, var(--color-border) 25%, var(--color-surface-hover) 50%, var(--color-border) 75%);
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
  border-radius: var(--radius-md);
}

@keyframes shimmer {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

.item-card--skeleton .item-card__emoji {
  background: var(--color-border);
}

.item-card--skeleton .skeleton-text {
  height: 16px;
  margin-bottom: var(--space-2);
}

.item-card--skeleton .skeleton-text--short {
  width: 60%;
}

/* ----------------- Toast Notification ----------------- */
.toast {
  position: fixed;
  bottom: 100px;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background: var(--color-text);
  color: white;
  padding: var(--space-3) var(--space-5);
  border-radius: var(--radius-lg);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  box-shadow: var(--shadow-lg);
  opacity: 0;
  transition: all var(--transition-base);
  z-index: 300;
}

.toast--visible {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

.toast--success {
  background: var(--color-fresh);
}

.toast--error {
  background: var(--color-expired);
}

/* ----------------- 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: 0;
}

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