/* CSS Variables for design system */
:root[data-theme="light"] {
  --bg-color: #f5f5f7;
  --card-bg: #ffffff;
  --border-color: rgba(0, 0, 0, 0.08);
  --border-focus: #000000;
  --text-primary: #121214;
  --text-secondary: #6e6e73;
  --text-muted: #aeaeaf;
  --accent-color: #000000;
  --accent-bg: #121214;
  --accent-text: #ffffff;
  --card-shadow: 0 4px 20px rgba(0, 0, 0, 0.03), 0 1px 3px rgba(0, 0, 0, 0.02);
  --card-shadow-hover: 0 12px 30px rgba(0, 0, 0, 0.06), 0 2px 8px rgba(0, 0, 0, 0.04);
  --best-badge-bg: #121214;
  --best-badge-text: #ffffff;
  --delete-hover-bg: rgba(0, 0, 0, 0.05);
  --chart-bar-bg: #121214;
  --chart-bar-track: #e5e5ea;
  --glow-opacity: 0.03;
}

:root[data-theme="dark"] {
  --bg-color: #0a0a0c;
  --card-bg: #131316;
  --border-color: rgba(255, 255, 255, 0.06);
  --border-focus: #ffffff;
  --text-primary: #f3f3f5;
  --text-secondary: #929299;
  --text-muted: #57575e;
  --accent-color: #ffffff;
  --accent-bg: #ffffff;
  --accent-text: #0a0a0c;
  --card-shadow: 0 4px 20px rgba(0, 0, 0, 0.3), 0 1px 3px rgba(0, 0, 0, 0.2);
  --card-shadow-hover: 0 12px 40px rgba(0, 0, 0, 0.5), 0 2px 10px rgba(0, 0, 0, 0.3);
  --best-badge-bg: #ffffff;
  --best-badge-text: #0a0a0c;
  --delete-hover-bg: rgba(255, 255, 255, 0.06);
  --chart-bar-bg: #ffffff;
  --chart-bar-track: #242429;
  --glow-opacity: 0.15;
}

/* Base resets & styles */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: 'Outfit', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background-color: var(--bg-color);
  color: var(--text-primary);
  line-height: 1.5;
  transition: background-color 0.4s cubic-bezier(0.16, 1, 0.3, 1), color 0.4s cubic-bezier(0.16, 1, 0.3, 1);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  position: relative;
  overflow-x: hidden;
}

/* Background glow effect for premium feel */
.glow-effect {
  position: fixed;
  top: -10%;
  left: 50%;
  transform: translateX(-50%);
  width: 80vw;
  height: 60vh;
  background: radial-gradient(circle, rgba(255,255,255,1) 0%, rgba(255,255,255,0) 70%);
  filter: blur(100px);
  pointer-events: none;
  opacity: var(--glow-opacity);
  z-index: 0;
  transition: opacity 0.4s ease;
}

[data-theme="light"] .glow-effect {
  background: radial-gradient(circle, rgba(0,0,0,1) 0%, rgba(0,0,0,0) 70%);
}

/* Header styling */
header {
  position: relative;
  z-index: 10;
  border-bottom: 1px solid var(--border-color);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  background: transparent;
}

.header-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1.5rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo-area h1 {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  font-family: 'Space Mono', monospace;
  color: var(--text-primary);
}

.subtitle {
  font-size: 0.75rem;
  color: var(--text-secondary);
  letter-spacing: 0.05em;
  margin-top: 0.25rem;
}

/* Theme Toggle Button */
.icon-button {
  background: transparent;
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  width: 40px;
  height: 40px;
  border-radius: 50%;
  cursor: pointer;
  display: grid;
  place-items: center;
  transition: all 0.2s ease;
}

.icon-button:hover {
  border-color: var(--text-primary);
  background-color: var(--delete-hover-bg);
}

.icon-button svg {
  width: 18px;
  height: 18px;
  transition: transform 0.3s ease;
}

.icon-button:active svg {
  transform: scale(0.9);
}

/* Icon toggles based on theme */
[data-theme="light"] .sun-icon { display: none; }
[data-theme="light"] .moon-icon { display: block; }
[data-theme="dark"] .sun-icon { display: block; }
[data-theme="dark"] .moon-icon { display: none; }

/* Main Container Layout */
.container {
  flex: 1;
  max-width: 1200px;
  width: 100%;
  margin: 0 auto;
  padding: 3rem 2rem;
  padding-bottom: 7rem; /* Space for bottom nav */
  display: block;
  z-index: 10;
}

.tab-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr;
  gap: 3rem;
}

@media (max-width: 968px) {
  .container {
    padding: 1.5rem 1rem;
    padding-bottom: 7rem;
  }
  .tab-grid {
    grid-template-columns: 1fr;
    gap: 2.5rem;
  }
}

/* Sections */
.cards-section, .results-section {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.section-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 0.75rem;
}

.section-title {
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-secondary);
}

.badge {
  font-family: 'Space Mono', monospace;
  font-size: 0.75rem;
  padding: 0.25rem 0.6rem;
  border: 1px solid var(--border-color);
  border-radius: 999px;
  color: var(--text-secondary);
}

/* Items Grid & Card Styling */
.items-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.25rem;
  align-content: start;
}

.item-card {
  background-color: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: 14px;
  padding: 1.25rem;
  box-shadow: var(--card-shadow);
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  display: flex;
  flex-direction: column;
  gap: 1rem;
  position: relative;
  overflow: hidden;
  animation: cardFadeIn 0.4s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

@keyframes cardFadeIn {
  from {
    opacity: 0;
    transform: translateY(15px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.item-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--card-shadow-hover);
  border-color: rgba(255, 255, 255, 0.15);
}

[data-theme="light"] .item-card:hover {
  border-color: rgba(0, 0, 0, 0.15);
}

/* Best Value Highlight Style */
.item-card.best-value-highlight {
  border-color: var(--accent-color);
  box-shadow: 0 8px 30px rgba(255, 255, 255, 0.05), var(--card-shadow);
}

[data-theme="light"] .item-card.best-value-highlight {
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.05), var(--card-shadow);
}

.item-card.best-value-highlight::before {
  content: 'BEST VALUE';
  position: absolute;
  top: 0;
  right: 0;
  background-color: var(--best-badge-bg);
  color: var(--best-badge-text);
  font-family: 'Space Mono', monospace;
  font-size: 0.625rem;
  font-weight: 700;
  padding: 0.25rem 0.75rem;
  border-bottom-left-radius: 8px;
  letter-spacing: 0.05em;
  opacity: 0.9;
}

.item-card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.item-index-label {
  font-family: 'Space Mono', monospace;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--text-muted);
}

.delete-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  width: 28px;
  height: 28px;
  border-radius: 50%;
  cursor: pointer;
  display: grid;
  place-items: center;
  transition: all 0.2s ease;
}

.delete-btn:hover {
  color: var(--text-primary);
  background-color: var(--delete-hover-bg);
}

.delete-btn svg {
  width: 14px;
  height: 14px;
}

/* Forms & Inputs */
.item-card-body {
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.input-group {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.full-width {
  width: 100%;
}

.input-row {
  display: flex;
  gap: 0.75rem;
}

.flex-2 { flex: 2; }
.flex-1 { flex: 1; }

.input-label {
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-secondary);
}

.input-field {
  background-color: transparent;
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  padding: 0.6rem 0.8rem;
  font-size: 0.875rem;
  font-family: inherit;
  border-radius: 8px;
  outline: none;
  transition: all 0.2s ease;
  width: 100%;
}

.input-field::placeholder {
  color: var(--text-muted);
  opacity: 0.6;
}

.input-field:focus {
  border-color: var(--border-focus);
}

/* Chrome/Safari/Edge number input spin controls hide */
.input-field[type="number"]::-webkit-outer-spin-button,
.input-field[type="number"]::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}
.input-field[type="number"] {
  -moz-appearance: textfield;
}

.price-input-wrapper {
  position: relative;
  display: flex;
  align-items: center;
}

.currency-symbol {
  position: absolute;
  left: 0.8rem;
  font-size: 0.875rem;
  color: var(--text-secondary);
  font-family: 'Space Mono', monospace;
  pointer-events: none;
}

.price-input-wrapper .input-field {
  padding-left: 1.8rem;
  font-family: 'Space Mono', monospace;
}

/* Card footer (calculated values) */
.item-card-footer {
  border-top: 1px dashed var(--border-color);
  padding-top: 0.75rem;
  margin-top: 0.25rem;
  display: flex;
  justify-content: flex-end;
  transition: opacity 0.3s ease;
}

.item-card-footer.hidden {
  opacity: 0;
  pointer-events: none;
  margin: 0;
  padding: 0;
  border: none;
}

.calculated-unit-price {
  font-family: 'Space Mono', monospace;
  font-size: 0.8rem;
}

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

.calc-value {
  font-weight: 700;
  color: var(--text-primary);
}

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

/* Action buttons */
.action-bar {
  display: flex;
  gap: 1rem;
  margin-top: 0.5rem;
}

.btn {
  font-family: inherit;
  font-size: 0.875rem;
  font-weight: 500;
  padding: 0.75rem 1.25rem;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  outline: none;
}

.btn-icon svg {
  width: 16px;
  height: 16px;
}

.btn-secondary {
  background-color: transparent;
  border: 1px dashed var(--border-color);
  color: var(--text-primary);
  flex: 1;
}

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

.btn-tertiary {
  background-color: transparent;
  border: 1px solid transparent;
  color: var(--text-secondary);
  padding: 0.75rem 1rem;
}

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

/* Result Card & Analysis Styles */
.result-card {
  background-color: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: 14px;
  padding: 2rem;
  box-shadow: var(--card-shadow);
  min-height: 350px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  position: sticky;
  top: 2rem;
}

.no-data-msg {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 1.25rem;
  color: var(--text-secondary);
  font-size: 0.9rem;
  max-width: 280px;
  margin: 3rem auto 0 auto;
}

.huge-icon {
  width: 48px;
  height: 48px;
  color: var(--text-muted);
  opacity: 0.6;
}

.results-display {
  display: flex;
  flex-direction: column;
  gap: 2rem;
  animation: fadeIn 0.4s ease forwards;
}

.results-display.hidden {
  display: none !important;
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

.best-value-banner {
  border-left: 3px solid var(--accent-color);
  padding-left: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.best-label {
  font-family: 'Space Mono', monospace;
  font-size: 0.625rem;
  font-weight: 700;
  letter-spacing: 0.2em;
  color: var(--text-muted);
}

.best-name {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.02em;
}

.best-price-stat {
  display: flex;
  align-items: baseline;
  gap: 0.35rem;
  margin-top: 0.25rem;
}

.stat-value {
  font-family: 'Space Mono', monospace;
  font-size: 2.25rem;
  font-weight: 700;
  line-height: 1;
}

.stat-unit {
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.savings-msg {
  font-size: 0.825rem;
  color: var(--text-secondary);
  margin-top: 0.5rem;
}

/* Comparison Index / Chart */
.comparison-details {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.comparison-details h4 {
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-secondary);
}

.details-desc {
  font-size: 0.75rem;
  color: var(--text-muted);
  line-height: 1.4;
}

.chart-container {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-top: 0.5rem;
}

.chart-row {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.chart-row-meta {
  display: flex;
  justify-content: space-between;
  font-size: 0.8rem;
}

.chart-row-name {
  font-weight: 500;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 180px;
}

.chart-row-value {
  font-family: 'Space Mono', monospace;
  color: var(--text-secondary);
}

.chart-bar-outer {
  height: 8px;
  background-color: var(--chart-bar-track);
  border-radius: 999px;
  width: 100%;
  overflow: hidden;
  position: relative;
}

.chart-bar-inner {
  height: 100%;
  background-color: var(--chart-bar-bg);
  border-radius: 999px;
  width: 0%; /* JSで動的変化 */
  transition: width 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

.chart-row.best-row .chart-bar-inner {
  opacity: 1;
}

.chart-row:not(.best-row) .chart-bar-inner {
  opacity: 0.45;
}

/* Footer */
footer {
  border-top: 1px solid var(--border-color);
  padding: 2rem;
  text-align: center;
  font-family: 'Space Mono', monospace;
  font-size: 0.7rem;
  color: var(--text-muted);
  margin-top: auto;
  z-index: 10;
}

.hidden {
  display: none !important;
}

/* Primary Button for Save Action */
.btn-primary {
  background-color: var(--accent-bg);
  color: var(--accent-text);
  border: 1px solid var(--accent-color);
  font-weight: 600;
  width: 100%;
}

.btn-primary:hover {
  background-color: var(--text-secondary);
  color: var(--bg-color);
  box-shadow: 0 4px 15px rgba(255, 255, 255, 0.05);
}

[data-theme="light"] .btn-primary:hover {
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.05);
}

.results-actions {
  margin-top: 1.5rem;
}

/* Bottom Navigation Bar Styles */
.bottom-nav {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  height: 64px;
  background-color: rgba(19, 19, 22, 0.8);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-top: 1px solid var(--border-color);
  display: flex;
  justify-content: space-around;
  align-items: center;
  z-index: 1000;
  box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.2);
  transition: background-color 0.4s ease;
}

[data-theme="light"] .bottom-nav {
  background-color: rgba(255, 255, 255, 0.85);
  box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.02);
}

.nav-item {
  background: transparent;
  border: none;
  color: var(--text-secondary);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
  cursor: pointer;
  height: 100%;
  width: 100%;
  transition: all 0.2s ease;
  font-family: inherit;
  outline: none;
}

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

.nav-icon {
  width: 18px;
  height: 18px;
  transition: transform 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}

.nav-text {
  font-size: 0.65rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

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

.nav-item.active .nav-icon {
  transform: scale(1.1);
  stroke-width: 2.5px;
}

/* Toast Notification Styles */
.toast {
  position: fixed;
  bottom: 80px;
  left: 50%;
  transform: translateX(-50%) translateY(10px);
  background-color: var(--text-primary);
  color: var(--bg-color);
  padding: 0.6rem 1.5rem;
  border-radius: 999px;
  font-size: 0.8rem;
  font-weight: 500;
  letter-spacing: 0.05em;
  z-index: 1100;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
  opacity: 0;
  pointer-events: none;
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

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

/* Saved History Styles */
.history-section {
  max-width: 800px;
  margin: 0 auto;
  animation: fadeIn 0.4s ease forwards;
}

.history-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-top: 1rem;
}

.history-card {
  background-color: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  box-shadow: var(--card-shadow);
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  overflow: hidden;
}

.history-card:hover {
  border-color: rgba(255, 255, 255, 0.12);
  box-shadow: var(--card-shadow-hover);
}

[data-theme="light"] .history-card:hover {
  border-color: rgba(0, 0, 0, 0.12);
}

.history-card-header {
  padding: 1.25rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  user-select: none;
}

.history-header-main {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.history-date {
  font-family: 'Space Mono', monospace;
  font-size: 0.75rem;
  color: var(--text-muted);
}

.history-summary {
  font-size: 0.95rem;
  font-weight: 600;
}

.history-best-pill {
  font-size: 0.7rem;
  font-weight: 700;
  background-color: var(--delete-hover-bg);
  padding: 0.15rem 0.5rem;
  border-radius: 4px;
  border: 1px solid var(--border-color);
}

.history-header-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.history-chevron {
  width: 16px;
  height: 16px;
  color: var(--text-secondary);
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

.history-card.expanded .history-chevron {
  transform: rotate(180deg);
}

/* History Card Content (Accordion Details) */
.history-card-details {
  border-top: 1px solid var(--border-color);
  background-color: rgba(0, 0, 0, 0.05);
  display: grid;
  grid-template-rows: 0fr;
  transition: grid-template-rows 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

[data-theme="light"] .history-card-details {
  background-color: rgba(0, 0, 0, 0.01);
}

.history-card.expanded .history-card-details {
  grid-template-rows: 1fr;
}

.history-details-inner {
  overflow: hidden;
  padding: 0 1.25rem;
  transition: padding 0.3s ease;
}

.history-card.expanded .history-details-inner {
  padding: 1.25rem;
}

/* History Data Table */
.history-table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 1.25rem;
}

.history-table th, .history-table td {
  text-align: left;
  padding: 0.5rem 0;
  font-size: 0.8rem;
  border-bottom: 1px solid var(--border-color);
}

.history-table th {
  color: var(--text-secondary);
  font-weight: 600;
  text-transform: uppercase;
  font-size: 0.7rem;
  letter-spacing: 0.05em;
}

.history-table td {
  font-family: 'Space Mono', monospace;
}

.history-table tr:last-child td {
  border-bottom: none;
}

.history-table td.item-name-cell {
  font-family: inherit;
  font-weight: 500;
}

.history-table tr.best-row td {
  font-weight: 700;
  color: var(--text-primary);
}

.history-actions-row {
  display: flex;
  gap: 0.75rem;
  justify-content: flex-end;
}

.btn-history-action {
  font-size: 0.75rem;
  padding: 0.4rem 0.8rem;
  border-radius: 6px;
}