:root {
  --primary: #007aff;
  --primary-hover: #0056b3;
  --success: #34c759;
  --danger: #ff3b30;
  --warning: #ff9500;
  --bg-primary: #f2f2f7;
  --bg-secondary: #ffffff;
  --bg-tertiary: #f2f2f7;
  --text-primary: #000000;
  --text-secondary: #8e8e93;
  --text-placeholder: #aeaeb2;
  --border-color: #e5e5ea;
  --card-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
  --modal-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
  --safe-top: env(safe-area-inset-top, 0px);
  --safe-bottom: env(safe-area-inset-bottom, 0px);
}

@media (prefers-color-scheme: dark) {
  :root {
    --primary: #0a84ff;
    --primary-hover: #409cff;
    --success: #30d158;
    --danger: #ff453a;
    --warning: #ff9f0a;
    --bg-primary: #1c1c1e;
    --bg-secondary: #2c2c2e;
    --bg-tertiary: #3a3a3c;
    --text-primary: #ffffff;
    --text-secondary: #aeaeb2;
    --text-placeholder: #636366;
    --border-color: #38383a;
    --card-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
    --modal-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
  }
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-tap-highlight-color: transparent;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.4;
  overflow-x: hidden;
  padding-top: calc(var(--safe-top) + 16px);
  padding-bottom: calc(var(--safe-bottom) + 32px);
  transition: background-color 0.3s ease, color 0.3s ease;
}

/* Container */
.container {
  max-width: 600px;
  margin: 0 auto;
  padding: 0 16px;
}

/* Header */
header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
}

h1 {
  font-size: 28px;
  font-weight: 700;
  letter-spacing: -0.5px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 16px;
  border-radius: 12px;
  font-size: 15px;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: all 0.2s ease;
  user-select: none;
}

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

.btn-primary:active {
  transform: scale(0.97);
  background-color: var(--primary-hover);
}

.btn-secondary {
  background-color: var(--bg-tertiary);
  color: var(--text-primary);
}

.btn-secondary:active {
  transform: scale(0.97);
}

.btn-danger {
  background-color: var(--danger);
  color: #ffffff;
}

.btn-danger:active {
  transform: scale(0.97);
  opacity: 0.9;
}

/* Search Bar */
.search-container {
  position: relative;
  margin-bottom: 20px;
}

.search-input {
  width: 100%;
  padding: 12px 16px 12px 42px;
  border-radius: 12px;
  border: none;
  background-color: var(--bg-secondary);
  color: var(--text-primary);
  font-size: 16px;
  box-shadow: var(--card-shadow);
  outline: none;
  transition: all 0.2s ease;
}

.search-input:focus {
  box-shadow: 0 0 0 2px var(--primary);
}

.search-icon {
  position: absolute;
  left: 14px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-secondary);
  pointer-events: none;
  width: 18px;
  height: 18px;
}

.clear-search {
  position: absolute;
  right: 14px;
  top: 50%;
  transform: translateY(-50%);
  background: none;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  display: none;
  padding: 4px;
}

/* Stock List Grid */
.stock-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
}

@media (max-width: 360px) {
  .stock-grid {
    grid-template-columns: 1fr;
  }
}

.stock-card {
  background-color: var(--bg-secondary);
  border-radius: 16px;
  overflow: hidden;
  box-shadow: var(--card-shadow);
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  display: flex;
  flex-direction: column;
}

.stock-card:active {
  transform: scale(0.97);
}

.card-img-wrapper {
  position: relative;
  width: 100%;
  padding-top: 100%; /* 1:1 Aspect Ratio */
  background-color: var(--bg-tertiary);
  overflow: hidden;
}

.card-img {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.card-placeholder {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  color: var(--text-secondary);
  font-size: 13px;
  gap: 6px;
}

.card-placeholder svg {
  width: 40px;
  height: 40px;
  opacity: 0.4;
}

.card-info {
  padding: 10px 12px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.card-name {
  font-weight: 600;
  font-size: 15px;
  color: var(--text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.card-meta {
  display: flex;
  justify-content: space-between;
  font-size: 12px;
  color: var(--text-secondary);
}

.card-location {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  flex: 1;
  margin-right: 4px;
}

.card-qty {
  font-weight: bold;
  color: var(--primary);
}

/* Empty State */
.empty-state {
  text-align: center;
  padding: 60px 20px;
  color: var(--text-secondary);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
}

.empty-state svg {
  width: 80px;
  height: 80px;
  opacity: 0.3;
}

/* Modal Overlay Base */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.4);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  z-index: 1000;
  display: flex;
  justify-content: center;
  align-items: flex-end; /* Modern bottom-sheet on mobile */
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease;
}

@media (min-width: 600px) {
  .modal-overlay {
    align-items: center; /* Centered modal on desktop */
  }
}

.modal-overlay.active {
  opacity: 1;
  pointer-events: auto;
}

.modal-content {
  background-color: var(--bg-secondary);
  width: 100%;
  max-width: 600px;
  border-top-left-radius: 24px;
  border-top-right-radius: 24px;
  box-shadow: var(--modal-shadow);
  padding: 20px;
  padding-bottom: calc(var(--safe-bottom) + 24px);
  max-height: 92vh;
  overflow-y: auto;
  transform: translateY(100%);
  transition: transform 0.3s cubic-bezier(0.1, 0.76, 0.55, 0.94);
}

@media (min-width: 600px) {
  .modal-content {
    border-radius: 24px;
    padding-bottom: 24px;
    max-height: 85vh;
    transform: translateY(50px);
  }
}

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

/* Modal Header styling for Continuous Add Form */
.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 12px;
}

.modal-title {
  font-size: 18px;
  font-weight: 700;
}

.modal-nav {
  display: flex;
  gap: 12px;
  align-items: center;
}

/* Form Styling */
.form-group {
  margin-bottom: 16px;
}

.form-label {
  display: block;
  font-size: 14px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 6px;
}

.form-input {
  width: 100%;
  padding: 12px;
  border-radius: 10px;
  border: 1px solid var(--border-color);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  font-size: 16px;
  outline: none;
  transition: border-color 0.2s ease;
}

.form-input:focus {
  border-color: var(--primary);
  background-color: var(--bg-secondary);
}

/* Photos upload grid */
.photo-upload-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  margin-bottom: 16px;
}

.photo-uploader {
  position: relative;
  width: 100%;
  padding-top: 100%; /* 1:1 Aspect */
  background-color: var(--bg-primary);
  border: 1px dashed var(--text-secondary);
  border-radius: 16px;
  cursor: pointer;
  overflow: hidden;
  transition: all 0.2s ease;
}

.photo-uploader:active {
  transform: scale(0.97);
}

.uploader-inner {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  color: var(--text-secondary);
  font-size: 13px;
  text-align: center;
  padding: 12px;
  gap: 8px;
}

.uploader-inner svg {
  width: 32px;
  height: 32px;
  color: var(--text-secondary);
}

.preview-img {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.btn-remove-photo {
  position: absolute;
  top: 8px;
  right: 8px;
  background-color: rgba(0, 0, 0, 0.6);
  border: none;
  border-radius: 50%;
  width: 24px;
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #ffffff;
  cursor: pointer;
  z-index: 10;
}

/* Detail view styling */
.detail-photos {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  margin-bottom: 20px;
}

.detail-photo-box {
  position: relative;
  width: 100%;
  padding-top: 100%; /* 1:1 Aspect */
  background-color: var(--bg-primary);
  border-radius: 16px;
  overflow: hidden;
}

.detail-img {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.detail-info-row {
  display: flex;
  border-bottom: 1px solid var(--border-color);
  padding: 12px 0;
  font-size: 16px;
}

.detail-info-label {
  width: 80px;
  font-weight: 600;
  color: var(--text-secondary);
}

.detail-info-value {
  flex: 1;
  color: var(--text-primary);
}

.detail-actions {
  display: flex;
  gap: 12px;
  margin-top: 24px;
}

.btn-full-width {
  flex: 1;
}

/* Toast Notification style */
.toast {
  position: fixed;
  bottom: 30px;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background-color: rgba(0, 0, 0, 0.85);
  color: #ffffff;
  padding: 10px 20px;
  border-radius: 20px;
  font-size: 14px;
  z-index: 2000;
  pointer-events: none;
  transition: transform 0.3s cubic-bezier(0.18, 0.89, 0.32, 1.28), opacity 0.3s;
  opacity: 0;
}

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

/* Manual backup: retain the existing header, cards and modal style. */
.header-actions { display: flex; gap: 8px; align-items: center; }
.backup-heading { display: flex; justify-content: space-between; align-items: center; margin-bottom: 16px; }
.backup-note { color: var(--text-secondary); font-size: 13px; line-height: 1.6; margin: 12px 0; }
.backup-actions { display: flex; flex-wrap: wrap; gap: 10px; }
.backup-status { white-space: pre-wrap; overflow-wrap: anywhere; padding: 12px; margin: 16px 0; border-radius: 10px; background: var(--bg-primary); line-height: 1.6; font-size: 14px; }
.backup-verify { border-top: 1px solid var(--border-color); padding-top: 16px; }
#btn-backup-verify { margin-top: 10px; }
#backup-modal button:disabled { opacity: 0.5; cursor: wait; }
#backup-modal [hidden] { display: none; }

/* V1.4: touch targets and scroll-local controls; item logic is unchanged. */
#add-modal .modal-header {
  position: sticky;
  top: -20px;
  z-index: 2;
  background: var(--bg-secondary);
  padding-top: 20px;
  margin-top: -20px;
  gap: 12px;
  flex-wrap: wrap;
}
#add-modal .modal-nav {
  flex-shrink: 0;
  flex-wrap: nowrap;
}
#add-modal .modal-header button,
#add-modal #session-indicator {
  flex-shrink: 0;
  white-space: nowrap;
}
#add-modal #btn-session-add,
#add-modal #btn-session-next {
  min-height: 48px;
  min-width: 64px;
}
@media (max-width: 599px) {
  #add-modal .modal-header {
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto;
  }
  #add-modal .modal-nav {
    grid-column: 1 / -1;
    gap: 12px;
  }
  #add-modal #btn-session-next { margin-left: auto; }
}
/* Keep focused fields below the sticky controls when the sheet scrolls. */
#add-modal .modal-content { scroll-padding-top: 156px; }