/* ============================================
   Split Bills Fairly - Styles
   Matching Steps2Miles design system
   ============================================ */

/* CSS Custom Properties */
:root {
  --color-primary: #F54900;
  --color-primary-dark: #d94000;
  --color-primary-light: #FF8904;
  --color-orange-100: #fed7aa;
  --color-success: #10b981;
  --color-error: #ef4444;

  --color-bg: #FFF7ED;
  --color-white: #ffffff;
  --color-text: #1f2937;
  --color-text-light: #6b7280;
  --color-text-muted: #9ca3af;
  --color-border: #e5e7eb;
  --color-border-light: #f3f4f6;

  --font-sans: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, 'SF Mono', Menlo, Consolas, monospace;

  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);

  --radius-sm: 0.375rem;
  --radius: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.25rem;
  --radius-3xl: 1.5rem;
  --radius-full: 9999px;

  --transition: 150ms ease;
}

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

* {
  margin: 0;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 5rem;
}

body {
  font-family: var(--font-sans);
  font-size: 1rem; /* 16px base */
  line-height: 1.5; /* 24px */
  font-weight: 400;
  color: var(--color-text);
  background: var(--color-bg);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  -webkit-font-smoothing: antialiased;
}

main {
  flex: 1;
}

img, picture, video, canvas, svg {
  display: block;
  max-width: 100%;
}

input, button, textarea, select {
  font: inherit;
}

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

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

a:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

h1, h2, h3, h4 {
  color: var(--color-text);
  font-weight: 600;
}

h1 {
  font-size: clamp(1.75rem, 4vw, 2.25rem); /* 36px max */
  line-height: 1.11; /* 40px at 36px */
  letter-spacing: -0.025em; /* -0.9px at 36px */
}

h2 {
  font-size: clamp(1.125rem, 2.5vw, 1.25rem); /* 20px max */
  line-height: 1.4; /* 28px at 20px */
  letter-spacing: -0.025em; /* -0.5px at 20px */
}

h3 {
  font-size: 1rem; /* 16px */
  line-height: 1.5; /* 24px */
  letter-spacing: normal;
}

p {
  margin-bottom: 1rem;
}

p:last-child {
  margin-bottom: 0;
}

/* Layout */
.container {
  width: 100%;
  max-width: 52rem;
  margin: 0 auto;
  padding: 0 1rem;
}

.container--narrow {
  max-width: 48rem;
}

@media (min-width: 1200px) {
  .container {
    margin-left: calc((100vw - 72rem) / 2 + 1rem);
    margin-right: auto;
  }
}

/* Header & Navigation */
.header {
  background: var(--color-white);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 100;
}

.nav.container {
  max-width: 1100px;
  margin: 0 auto;
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 3.5rem;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--color-text);
  letter-spacing: -0.025em;
}

.nav-logo {
  width: 1.5rem;
  height: 1.5rem;
  flex-shrink: 0;
}

.nav-brand:hover {
  color: var(--color-text);
  text-decoration: none;
}

/* Style "Bills" in orange like "2" in Steps2Miles */
.nav-brand-text span {
  color: var(--color-primary);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 4px;
  width: 2rem;
  height: 2rem;
  padding: 0.25rem;
  background: transparent;
  border: none;
  cursor: pointer;
}

.nav-toggle span {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--color-text);
  transition: var(--transition);
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  list-style: none;
  padding: 0;
  margin: 0;
}

.nav-menu a {
  color: var(--color-text);
  font-size: 0.875rem; /* 14px */
  font-weight: 500;
  line-height: 1.43; /* 20px */
  padding: 0.5rem 0.75rem;
  border-radius: var(--radius-full);
  transition: var(--transition);
}

.nav-menu a:hover {
  color: var(--color-text);
  text-decoration: none;
  background: var(--color-border-light);
}

.nav-menu li:last-child a {
  border: 1px solid var(--color-border);
  margin-left: 0.5rem;
}

.nav-menu li:last-child a:hover {
  border-color: var(--color-text);
  background: transparent;
}

.nav-menu a[aria-current="page"] {
  color: var(--color-primary);
}

/* Mobile Navigation */
@media (max-width: 768px) {
  .nav-toggle {
    display: flex;
  }

  .nav-menu {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: var(--color-white);
    border-bottom: 1px solid var(--color-border);
    padding: 0.5rem 1rem 1rem;
    display: none;
    box-shadow: var(--shadow-md);
  }

  .nav-menu.active {
    display: flex;
  }

  .nav-menu a {
    padding: 0.75rem 0;
    border-radius: 0;
  }

  .nav-menu li:last-child a {
    border: none;
    margin-left: 0;
    margin-top: 0;
  }

  .nav-toggle[aria-expanded="true"] span:nth-child(1) {
    transform: translateY(6px) rotate(45deg);
  }

  .nav-toggle[aria-expanded="true"] span:nth-child(2) {
    opacity: 0;
  }

  .nav-toggle[aria-expanded="true"] span:nth-child(3) {
    transform: translateY(-6px) rotate(-45deg);
  }
}

/* Sections */
section {
  padding: 2rem 0;
}

@media (min-width: 768px) {
  section {
    padding: 2.5rem 0;
  }
}

/* Hero Card Section */
.intro {
  padding-top: 2rem;
  padding-bottom: 1rem;
}

.hero-card {
  background: var(--color-white);
  border-radius: var(--radius-3xl);
  padding: 1.5rem;
  border: 1px solid var(--color-orange-100);
  box-shadow: 0 1px 3px 0 rgba(0,0,0,0.1), 0 1px 2px -1px rgba(0,0,0,0.1);
}

.category-tag {
  display: inline-block;
  color: var(--color-primary);
  font-size: 0.75rem; /* 12px */
  font-weight: 500;
  line-height: 1.33; /* 16px */
  margin-bottom: 0.75rem;
  background: var(--color-bg);
  padding: 0.25rem 0.75rem;
  border-radius: var(--radius-full);
}

.intro h1 {
  margin-bottom: 1rem;
}

.intro-text {
  color: var(--color-text);
  font-size: 1rem; /* 16px */
  font-weight: 400;
  line-height: 1.5; /* 24px */
  max-width: 600px;
}

/* Calculator Section */
.calculator-section {
  padding-top: 1.5rem;
}

.calculator-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 1.25rem;
  flex-wrap: wrap;
  gap: 1rem;
}

.calculator-header h2 {
  margin-bottom: 0.25rem;
}

.calculator-header p {
  color: var(--color-text-light);
  font-size: 0.9375rem;
  margin: 0;
}

/* Calculator Card */
.calculator-card {
  background: var(--color-white);
  border-radius: var(--radius-3xl);
  padding: 1.5rem;
  border: 1px solid var(--color-orange-100);
  box-shadow: 0 1px 3px 0 rgba(0,0,0,0.1), 0 1px 2px -1px rgba(0,0,0,0.1);
}

/* Tabs / Method Buttons */
.tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1rem;
}

.tab {
  padding: 0.5rem 1rem;
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-text);
  cursor: pointer;
  transition: var(--transition);
}

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

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

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

/* Tab Panels */
.tab-panel {
  display: none;
}

.tab-panel.active {
  display: block;
}

/* Calculator Layout */
.calculator-layout {
  display: grid;
  gap: 1rem;
}

@media (min-width: 640px) {
  .calculator-layout {
    grid-template-columns: 1fr 1fr;
    align-items: start;
  }
}

/* Callout */
.callout {
  background: var(--color-bg);
  border-left: 3px solid var(--color-primary-light);
  border-radius: var(--radius);
  padding: 1rem 1.25rem;
  margin-bottom: 1rem;
}

@media (min-width: 640px) {
  .callout {
    margin-bottom: 0;
  }
}

.callout p {
  font-size: 0.875rem;
  color: var(--color-text-light);
  margin: 0;
  line-height: 1.6;
}

/* Form Elements */
.form-group {
  margin-bottom: 0.625rem;
}

label {
  display: block;
  font-size: 0.875rem; /* 14px */
  font-weight: 500;
  line-height: 1.43; /* 20px */
  color: var(--color-text);
  margin-bottom: 0.25rem;
}

input[type="text"],
input[type="number"] {
  width: 100%;
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  font-size: 0.9375rem;
  color: var(--color-text);
  background: var(--color-white);
  transition: var(--transition);
}

input[type="text"]:hover,
input[type="number"]:hover {
  border-color: var(--color-text-muted);
}

input[type="text"]:focus,
input[type="number"]:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(245, 73, 0, 0.1);
}

input[type="text"].error,
input[type="number"].error {
  border-color: var(--color-error);
}

.error-msg {
  display: block;
  font-size: 0.75rem;
  color: var(--color-error);
  margin-top: 0.375rem;
  min-height: 1rem;
}

/* Form Section */
.form-section {
  display: flex;
  flex-direction: column;
}

/* Result Box - Orange style */
.result-box {
  background: linear-gradient(145deg, #ffad42 0%, #ff9a1f 50%, #f58b00 100%);
  border-radius: var(--radius-3xl);
  padding: 1rem 1.25rem;
  color: var(--color-text);
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  box-shadow:
    0 4px 12px rgba(245, 73, 0, 0.25),
    0 2px 4px rgba(0, 0, 0, 0.1),
    inset 0 1px 0 rgba(255, 255, 255, 0.2),
    inset 0 -2px 4px rgba(0, 0, 0, 0.1);
}

.result-label {
  font-size: 0.875rem;
  font-weight: 700;
}

.result-main {
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
}

.result-value {
  font-size: 2.25rem;
  font-weight: 700;
  line-height: 1;
}

.result-unit {
  font-size: 1.125rem;
  font-weight: 500;
}

.result-meta {
  font-size: 0.8125rem;
  font-weight: 500;
}

.result-note {
  background: rgba(255, 255, 255, 0.95);
  color: var(--color-text);
  border-radius: var(--radius);
  padding: 0.75rem 1rem;
  font-size: 0.8125rem;
  line-height: 1.5;
  margin-top: 0.25rem;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.5rem 1.25rem;
  font-size: 0.875rem;
  font-weight: 500;
  border: none;
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: var(--transition);
  text-decoration: none;
}

.btn:hover {
  text-decoration: none;
}

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

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

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

.btn-secondary {
  background: var(--color-white);
  color: var(--color-text);
  border: 1px solid var(--color-border);
}

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

.btn-outline {
  background: transparent;
  color: var(--color-text);
  border: 1px solid var(--color-border);
}

.btn-outline:hover {
  border-color: var(--color-text);
  color: var(--color-text);
}

.btn-sm {
  padding: 0.375rem 0.875rem;
  font-size: 0.8125rem;
}

.btn-copy {
  padding: 0.375rem 0.75rem;
  font-size: 0.75rem;
  background: rgba(255, 255, 255, 0.6);
  color: var(--color-text);
  border: 1px solid rgba(0, 0, 0, 0.1);
  border-radius: var(--radius);
  cursor: pointer;
  transition: var(--transition);
  font-weight: 500;
}

.btn-copy:hover {
  background: rgba(255, 255, 255, 0.9);
}

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

.btn-reset {
  padding: 0.375rem 0.75rem;
  font-size: 0.75rem;
  background: rgba(255, 255, 255, 0.6);
  color: var(--color-text);
  border: 1px solid rgba(0, 0, 0, 0.1);
  border-radius: var(--radius);
  cursor: pointer;
  transition: var(--transition);
  font-weight: 500;
}

.btn-reset:hover {
  background: rgba(255, 255, 255, 0.9);
}

.result-actions {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

/* Calculator Actions */
.calculator-actions {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-bottom: 1rem;
}

/* Table Controls */
.table-controls {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 1rem;
  flex-wrap: wrap;
}

/* Expense Table */
.table-wrapper {
  overflow-x: auto;
  margin-bottom: 1.25rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}

.expense-table {
  width: 100%;
  border-collapse: collapse;
  min-width: 400px;
}

.expense-table th,
.expense-table td {
  padding: 0.75rem;
  text-align: left;
  border-bottom: 1px solid var(--color-border);
}

.expense-table th {
  background: var(--color-bg);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--color-text-light);
  text-transform: uppercase;
  letter-spacing: 0.03em;
  white-space: nowrap;
  position: relative;
}

.expense-table th input {
  width: 100%;
  min-width: 70px;
  padding: 0.25rem 0.375rem;
  font-size: 0.75rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-white);
  text-transform: uppercase;
  font-weight: 600;
  color: var(--color-text-light);
}

.expense-table th input:focus {
  border-color: var(--color-primary);
  background: var(--color-white);
  outline: none;
  text-transform: none;
  color: var(--color-text);
}

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

.expense-table tfoot td {
  background: var(--color-bg);
  font-weight: 600;
  border-bottom: none;
  border-top: 2px solid var(--color-border);
}

.sticky-col {
  position: sticky;
  left: 0;
  background: var(--color-white);
  z-index: 1;
  min-width: 120px;
}

.expense-table thead .sticky-col {
  background: var(--color-bg);
  z-index: 2;
}

.expense-table tfoot .sticky-col {
  background: var(--color-bg);
}

.sticky-col input {
  width: calc(100% - 24px);
}

.total-col {
  background: var(--color-bg);
  font-weight: 500;
  white-space: nowrap;
}

.expense-input {
  width: 100%;
  min-width: 70px;
  padding: 0.5rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  text-align: right;
  font-size: 0.875rem;
}

.expense-input:focus {
  outline: none;
  border-color: var(--color-primary);
}

.person-name {
  padding: 0.5rem;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
}

.person-name:focus {
  border-color: var(--color-primary);
  outline: none;
}

.btn-remove-row,
.btn-remove-col {
  width: 18px;
  height: 18px;
  padding: 0;
  background: var(--color-border);
  border: none;
  border-radius: 50%;
  color: var(--color-text-light);
  font-size: 0.875rem;
  line-height: 1;
  cursor: pointer;
  transition: var(--transition);
  position: absolute;
  right: 4px;
  top: 50%;
  transform: translateY(-50%);
}

.sticky-col {
  position: relative;
}

.sticky-col .btn-remove-row {
  position: absolute;
  right: 8px;
  top: 50%;
  transform: translateY(-50%);
}

.btn-remove-row:hover,
.btn-remove-col:hover {
  background: var(--color-error);
  color: var(--color-white);
}

.row-total {
  font-weight: 500;
  color: var(--color-text);
  font-size: 0.875rem;
}

/* Group Results */
.group-results {
  display: none;
  margin-top: 1rem;
}

.group-results.active {
  display: block;
}

.group-results h3 {
  font-size: 0.9375rem;
  margin-bottom: 0.5rem;
  color: var(--color-text);
}

.summary-section {
  margin-bottom: 1rem;
}

.summary-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.875rem; /* 14px */
  line-height: 1.43; /* 20px */
}

.summary-table th,
.summary-table td {
  padding: 0.5rem 0.625rem;
  text-align: left;
  border-bottom: 1px solid var(--color-border);
}

.summary-table th {
  background: var(--color-bg);
  font-weight: 600;
  color: var(--color-text-light);
  font-size: 0.75rem;
  text-transform: uppercase;
}

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

.net-positive {
  color: var(--color-success);
  font-weight: 600;
}

.net-negative {
  color: var(--color-error);
  font-weight: 600;
}

.settlement-section {
  background: linear-gradient(145deg, #ff5a1a 0%, #f54900 50%, #d94000 100%);
  border-radius: var(--radius-3xl);
  padding: 0.875rem 1rem;
  color: var(--color-white);
  box-shadow:
    0 4px 12px rgba(245, 73, 0, 0.3),
    0 2px 4px rgba(0, 0, 0, 0.1),
    inset 0 1px 0 rgba(255, 255, 255, 0.15),
    inset 0 -2px 4px rgba(0, 0, 0, 0.15);
}

.settlement-section h3 {
  color: var(--color-white);
  margin-bottom: 0.5rem;
}

.settlement-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.settlement-list li {
  padding: 0.375rem 0;
  font-size: 0.875rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.2);
}

.settlement-list li:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.settlement-amount {
  font-weight: 700;
}

.settlement-section .btn-copy {
  margin-top: 0.75rem;
  background: rgba(255, 255, 255, 0.2);
  border: 1px solid rgba(255, 255, 255, 0.4);
  color: var(--color-white);
}

.settlement-section .btn-copy:hover {
  background: rgba(255, 255, 255, 0.3);
}

.settlement-section .btn-copy.copied {
  background: rgba(255, 255, 255, 0.9);
  color: var(--color-primary);
}

.settlement-actions {
  display: flex;
  gap: 0.5rem;
  margin-top: 0.75rem;
  flex-wrap: wrap;
}

/* ============================================
   Fair Split (Scenarios) Calculator
   ============================================ */

/* Scenario Selector */
.scenario-selector {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 1rem;
  flex-wrap: wrap;
}

.scenario-tab {
  flex: 1;
  min-width: 140px;
  padding: 0.5rem 1rem;
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-text);
  cursor: pointer;
  transition: var(--transition);
  text-align: center;
}

.scenario-tab:hover {
  border-color: var(--color-text-muted);
}

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

.scenario-panel {
  display: none;
}

.scenario-panel.active {
  display: block;
}

/* People Manager */
.people-manager {
  margin-bottom: 1rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--color-border);
}

.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 0.5rem;
}

.section-header h3 {
  margin: 0;
  font-size: 0.9375rem;
}

.people-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.5rem;
}

.person-row {
  display: flex;
  align-items: center;
  gap: 0.375rem;
  background: var(--color-bg);
  border-radius: var(--radius);
  padding: 0.25rem 0.375rem;
}

.person-name-input {
  flex: 1;
  min-width: 0;
  padding: 0.25rem 0.375rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  background: var(--color-white);
}

.person-name-input:focus {
  outline: none;
  border-color: var(--color-primary);
}

.btn-remove-person {
  width: 20px;
  height: 20px;
  padding: 0;
  background: transparent;
  border: none;
  border-radius: 50%;
  color: var(--color-text-light);
  font-size: 0.875rem;
  line-height: 1;
  cursor: pointer;
  transition: var(--transition);
}

.btn-remove-person:hover {
  background: var(--color-error);
  color: var(--color-white);
}

/* Scenario Sections */
.scenario-section {
  margin-bottom: 0.875rem;
  padding-bottom: 0.875rem;
  border-bottom: 1px solid var(--color-border);
}

.scenario-section:last-of-type {
  border-bottom: none;
  padding-bottom: 0;
}

.scenario-section h3 {
  font-size: 0.9375rem;
  margin-bottom: 0.375rem;
}

.section-hint {
  font-size: 0.8125rem;
  color: var(--color-text-light);
  margin-bottom: 0.5rem;
}

/* Items List */
.items-list {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.item-row {
  background: var(--color-bg);
  border-radius: var(--radius);
  padding: 0.5rem 0.625rem;
}

.item-details {
  display: flex;
  gap: 0.375rem;
  margin-bottom: 0.375rem;
  align-items: flex-end;
}

.item-name-wrapper {
  width: 50%;
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 0.125rem;
}

.item-name-input,
.shared-item-name {
  width: 100%;
  padding: 0.375rem 0.5rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  background: var(--color-white);
}

.qty-wrapper {
  width: 20%;
  display: flex;
  flex-direction: column;
  gap: 0.125rem;
}

.price-wrapper {
  width: 20%;
  display: flex;
  flex-direction: column;
  gap: 0.125rem;
}

.item-label,
.qty-label,
.price-label {
  font-size: 0.625rem;
  color: var(--color-text-light);
  text-transform: uppercase;
  letter-spacing: 0.02em;
  margin: 0;
}

.item-qty-input {
  width: 100%;
  padding: 0.375rem 0.125rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  text-align: center;
  background: var(--color-white);
}

.item-amount-input,
.shared-item-amount {
  width: 100%;
  padding: 0.375rem 0.25rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  text-align: right;
  background: var(--color-white);
}

.btn-remove-item {
  width: 24px;
  height: 24px;
  padding: 0;
  padding-bottom: 1px;
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: 50%;
  color: var(--color-text-light);
  font-size: 0.875rem;
  line-height: 1;
  cursor: pointer;
  transition: var(--transition);
  flex-shrink: 0;
  align-self: flex-end;
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.btn-remove-item:hover {
  background: var(--color-error);
  border-color: var(--color-error);
  color: var(--color-white);
}

.item-participants {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.375rem;
}

.participants-label {
  font-size: 0.75rem;
  color: var(--color-text-light);
}

.checkbox-group {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem;
}

.checkbox-label {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  padding: 0.125rem 0.375rem;
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  cursor: pointer;
  transition: var(--transition);
}

.checkbox-label:has(input:checked) {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-white);
}

.checkbox-label input {
  display: none;
}

.item-error {
  font-size: 0.75rem;
  color: var(--color-error);
  margin-left: auto;
}

.item-payers {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.375rem;
  margin-top: 0.375rem;
  padding-top: 0.375rem;
  border-top: 1px dashed var(--color-border);
}

/* Toggle Row */
.toggle-row {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.875rem;
  font-weight: 500;
  cursor: pointer;
}

.toggle-row input[type="checkbox"] {
  width: 18px;
  height: 18px;
  accent-color: var(--color-primary);
}

/* Tax/Tip Section */
.tax-tip-section {
  margin-top: 0.5rem;
  padding: 0.5rem 0.625rem;
  background: var(--color-bg);
  border-radius: var(--radius);
}

.tax-tip-section.hidden {
  display: none;
}

/* Form Row */
.form-row {
  display: grid;
  gap: 0.75rem;
}

@media (min-width: 480px) {
  .form-row {
    grid-template-columns: 1fr 1fr;
  }
}

/* Radio Group */
.radio-group {
  display: flex;
  flex-direction: column;
  gap: 0.375rem;
}

.radio-label {
  display: flex;
  align-items: center;
  gap: 0.375rem;
  font-size: 0.8125rem;
  cursor: pointer;
}

.radio-label input {
  accent-color: var(--color-primary);
}

/* Payer Select */
.payer-select {
  width: 100%;
  padding: 0.375rem 0.5rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  font-size: 0.875rem;
  background: var(--color-white);
  cursor: pointer;
}

.payer-select:focus {
  outline: none;
  border-color: var(--color-primary);
}

/* Payer Bubble Group */
.payer-bubble-group {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.payer-bubble {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  padding: 0.375rem 0.75rem;
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  font-size: 0.875rem;
  cursor: pointer;
  transition: var(--transition);
}

.payer-bubble:hover {
  border-color: var(--color-text-muted);
}

.payer-bubble:has(input:checked) {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-white);
}

.payer-bubble input {
  display: none;
}

.payer-bubble-amount {
  display: none;
  margin-left: 0.25rem;
}

.payer-bubble:has(input:checked) .payer-bubble-amount {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
}

.payer-amount-input {
  width: 70px;
  padding: 0.125rem 0.25rem;
  border: 1px solid rgba(255, 255, 255, 0.3);
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  background: rgba(255, 255, 255, 0.2);
  color: var(--color-white);
  text-align: right;
}

.payer-amount-input::placeholder {
  color: rgba(255, 255, 255, 0.7);
}

.payer-amount-input:focus {
  outline: none;
  background: rgba(255, 255, 255, 0.3);
}

/* Running Totals */
.running-totals {
  background: var(--color-bg);
  border-radius: var(--radius);
  padding: 0.5rem 0.75rem;
  margin-bottom: 0.875rem;
}

.total-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.125rem 0;
  font-size: 0.8125rem;
}

.total-row.total-grand {
  border-top: 1px solid var(--color-border);
  margin-top: 0.25rem;
  padding-top: 0.375rem;
  font-weight: 600;
}

/* Nights Grid */
.nights-grid {
  display: grid;
  gap: 0.375rem;
}

.nights-row {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.875rem;
}

.nights-row label {
  flex: 1;
  min-width: 80px;
  margin: 0;
}

.nights-input {
  width: 60px;
  padding: 0.25rem 0.375rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  text-align: center;
}

.nights-input:focus {
  outline: none;
  border-color: var(--color-primary);
}

.nights-row span:last-child {
  color: var(--color-text-light);
  font-size: 0.8125rem;
}

/* Empty Hint */
.empty-hint {
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  font-style: italic;
  margin: 0;
}

/* Simple Table */
.simple-table {
  width: 100%;
}

.simple-table .action-col {
  width: 40px;
  text-align: center;
}

.simple-table .paid-input {
  width: 100%;
  min-width: 90px;
}

.simple-table .paid-input.readonly {
  background: var(--color-bg);
  color: var(--color-text);
  cursor: not-allowed;
}

/* Advanced Accordion */
.advanced-accordion {
  margin: 1.25rem 0;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background: var(--color-white);
}

.advanced-accordion summary {
  padding: 0.875rem 1.25rem;
  cursor: pointer;
  font-weight: 500;
  font-size: 0.875rem;
  color: var(--color-text);
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  transition: background var(--transition);
}

.advanced-accordion summary::-webkit-details-marker {
  display: none;
}

.advanced-accordion summary::after {
  content: '';
  width: 8px;
  height: 8px;
  border-right: 2px solid var(--color-primary);
  border-bottom: 2px solid var(--color-primary);
  transform: rotate(45deg);
  flex-shrink: 0;
  transition: transform 0.2s ease;
}

.advanced-accordion[open] summary::after {
  transform: rotate(-135deg);
}

.advanced-accordion summary:hover {
  background: var(--color-bg);
}

.advanced-accordion summary:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: -2px;
}

.advanced-content {
  padding: 0 1.25rem 1.25rem;
  border-top: 1px solid var(--color-border);
}

.advanced-hint {
  font-size: 0.8125rem;
  color: var(--color-text-light);
  margin: 1rem 0;
}

.advanced-content .table-controls {
  margin-bottom: 0.75rem;
}

.advanced-content .table-wrapper {
  margin-bottom: 0;
}

/* Person name display in advanced table */
.person-name-display {
  font-weight: 500;
  color: var(--color-text);
  font-size: 0.875rem;
}

/* Embed CTA */
.embed-cta {
  flex-shrink: 0;
}

/* Modal */
.modal {
  position: fixed;
  inset: 0;
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
}

.modal[hidden] {
  display: none;
}

.modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
}

.modal-content {
  position: relative;
  background: var(--color-white);
  border-radius: var(--radius-xl);
  padding: 2rem;
  max-width: 480px;
  width: 100%;
  box-shadow: var(--shadow-md);
}

.modal-close {
  position: absolute;
  top: 1rem;
  right: 1rem;
  width: 2rem;
  height: 2rem;
  background: var(--color-bg);
  border: none;
  border-radius: 50%;
  font-size: 1.25rem;
  cursor: pointer;
  transition: var(--transition);
  color: var(--color-text-light);
}

.modal-close:hover {
  background: var(--color-border);
  color: var(--color-text);
}

.modal h3 {
  margin-bottom: 0.75rem;
}

.modal p {
  color: var(--color-text-light);
  font-size: 0.9375rem;
}

.embed-code {
  width: 100%;
  height: 120px;
  padding: 0.75rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  resize: none;
  margin-bottom: 1rem;
  background: var(--color-bg);
}

/* Content Sections */
.content-section {
  padding: 2rem 0;
}

.content-section h2 {
  margin-bottom: 1rem;
}

.content-section p {
  color: var(--color-text);
  line-height: 1.7;
}

/* Info Box - with left border */
.info-box {
  background: var(--color-white);
  border-left: 3px solid var(--color-primary-light);
  border-radius: var(--radius);
  padding: 1.25rem 1.5rem;
  margin: 1.5rem 0;
  box-shadow: 0 1px 3px 0 rgba(0,0,0,0.1), 0 1px 2px -1px rgba(0,0,0,0.1);
}

.info-box p {
  font-size: 0.9375rem;
  margin: 0;
}

.info-box ul {
  margin: 0.75rem 0 0 0;
  padding-left: 1.25rem;
}

.info-box li {
  margin-bottom: 0.5rem;
  font-size: 0.9375rem;
}

/* Feature Grid */
.features-grid,
.use-cases-grid {
  display: grid;
  gap: 1rem;
}

@media (min-width: 640px) {
  .features-grid,
  .use-cases-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.feature-card,
.use-case-card {
  background: var(--color-white);
  border-radius: var(--radius-2xl);
  padding: 1.25rem 1.5rem;
  border: 1px solid var(--color-orange-100);
  box-shadow: 0 1px 3px 0 rgba(0,0,0,0.1), 0 1px 2px -1px rgba(0,0,0,0.1);
  transition: box-shadow var(--transition);
}

.feature-card:hover,
.use-case-card:hover {
  box-shadow: 0 2px 6px 0 rgba(0,0,0,0.12), 0 2px 4px -1px rgba(0,0,0,0.1);
}

.feature-card h3,
.use-case-card h3 {
  margin-bottom: 0.375rem;
  font-size: 1rem;
}

.feature-card p,
.use-case-card p {
  font-size: 1rem; /* 16px */
  font-weight: 400;
  color: var(--color-text-light);
  margin: 0;
  line-height: 1.5; /* 24px */
}

/* Methods Grid */
.methods-grid {
  display: grid;
  gap: 1rem;
}

@media (min-width: 640px) {
  .methods-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.method-card {
  background: var(--color-white);
  border-left: 3px solid var(--color-primary-light);
  border-radius: var(--radius);
  padding: 1.25rem 1.5rem;
  box-shadow: 0 1px 3px 0 rgba(0,0,0,0.1), 0 1px 2px -1px rgba(0,0,0,0.1);
  transition: box-shadow var(--transition);
}

.method-card:hover {
  box-shadow: 0 2px 6px 0 rgba(0,0,0,0.12), 0 2px 4px -1px rgba(0,0,0,0.1);
}

.method-card h3 {
  margin-bottom: 0.5rem;
}

.method-card h3 a {
  color: var(--color-primary);
}

.method-card p {
  font-size: 1rem; /* 16px */
  font-weight: 400;
  color: var(--color-text-light);
  margin: 0;
  line-height: 1.5; /* 24px */
}

/* Why Choose */
.why-choose h2 {
  margin-bottom: 1.25rem;
}

/* How It Works */
.how-it-works h2 {
  margin-bottom: 0.5rem;
}

.section-intro {
  font-size: 1rem; /* 16px */
  font-weight: 400;
  line-height: 1.5; /* 24px */
  color: var(--color-text-light);
  margin-bottom: 1.25rem;
}

/* When to Use */
.when-to-use h2 {
  margin-bottom: 0.5rem;
}

/* FAQ */
.faq h2 {
  margin-bottom: 1.25rem;
}

.faq-list {
  max-width: 100%;
}

.faq-item {
  background: var(--color-white);
  border-radius: var(--radius-2xl);
  margin-bottom: 0.75rem;
  border: 1px solid var(--color-orange-100);
  box-shadow: 0 1px 3px 0 rgba(0,0,0,0.1), 0 1px 2px -1px rgba(0,0,0,0.1);
  transition: box-shadow var(--transition);
}

.faq-item:hover {
  box-shadow: 0 2px 6px 0 rgba(0,0,0,0.12), 0 2px 4px -1px rgba(0,0,0,0.1);
}

.faq-item summary {
  padding: 1rem 1.25rem;
  font-weight: 500;
  font-size: 1rem; /* 16px */
  line-height: 1.5; /* 24px */
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  border-radius: var(--radius-2xl);
  transition: background var(--transition);
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  content: '';
  width: 10px;
  height: 10px;
  border-right: 2px solid var(--color-primary);
  border-bottom: 2px solid var(--color-primary);
  transform: rotate(45deg);
  flex-shrink: 0;
  transition: transform 0.25s ease;
  margin-right: 4px;
}

.faq-item[open] summary::after {
  transform: rotate(-135deg);
}

.faq-item summary:hover {
  background: var(--color-bg);
}

.faq-item summary:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: -2px;
}

.faq-item-content {
  overflow: hidden;
  max-height: 0;
  transition: max-height 0.3s ease-out, padding 0.3s ease-out;
  padding: 0 1.5rem;
}

.faq-item[open] .faq-item-content {
  max-height: 500px;
  padding: 0 1.5rem 1.25rem;
  transition: max-height 0.4s ease-in, padding 0.3s ease-in;
}

.faq-item p {
  color: var(--color-text-light);
  font-size: 1rem; /* 16px */
  font-weight: 400;
  line-height: 1.5; /* 24px */
  margin-bottom: 0.75rem;
}

.faq-item p:last-child {
  margin-bottom: 0;
}

/* Mini About */
.mini-about {
  padding: 2rem 0;
}

.about-card {
  background: var(--color-white);
  border-radius: var(--radius-3xl);
  padding: 1.5rem;
  border: 1px solid var(--color-orange-100);
  box-shadow: 0 1px 3px 0 rgba(0,0,0,0.1), 0 1px 2px -1px rgba(0,0,0,0.1);
}

.about-card h2 {
  margin-bottom: 1rem;
  font-size: 1.25rem;
}

.about-card p {
  font-size: 1rem; /* 16px */
  font-weight: 400;
  line-height: 1.5; /* 24px */
  color: var(--color-text);
  margin-bottom: 1.5rem;
}

.about-card .btn {
  margin-top: 0;
}

/* About Page */
.about-page {
  padding: 3rem 0;
  display: flex;
  justify-content: center;
}

.about-page .container {
  display: flex;
  justify-content: center;
}

.about-page-card {
  background: var(--color-white);
  border-radius: var(--radius-3xl);
  padding: 1.5rem;
  max-width: 40rem;
  border: 1px solid var(--color-orange-100);
  box-shadow: 0 1px 3px 0 rgba(0,0,0,0.1), 0 1px 2px -1px rgba(0,0,0,0.1);
}

.about-page-card .category-tag {
  margin-bottom: 0.5rem;
}

.about-page-card h1 {
  font-size: 1.75rem;
  margin-bottom: 1rem;
}

.about-page-card p {
  font-size: 1rem;
  font-weight: 400;
  line-height: 1.5;
  color: var(--color-text);
  margin-bottom: 1rem;
}

.about-page-card h2 {
  font-size: 1rem;
  font-weight: 600;
  margin-top: 1rem;
  margin-bottom: 0.5rem;
}

.about-buttons {
  display: flex;
  gap: 0.75rem;
  margin-top: 1.5rem;
  flex-wrap: wrap;
}

/* Footer */
.footer {
  background: var(--color-white);
  border-top: 1px solid var(--color-border);
  padding: 1.25rem 0;
  text-align: center;
  font-size: 0.75rem; /* 12px */
  font-weight: 400;
  line-height: 1.33; /* 16px */
  color: var(--color-text-light);
}

.footer .container {
  max-width: 1100px;
  margin: 0 auto;
}

.footer a {
  color: var(--color-text-light);
}

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

/* Return to Calculator Button */
.return-btn {
  position: fixed;
  left: 1rem;
  top: 50%;
  transform: translateY(-50%);
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 0.75rem 1rem;
  font-size: 0.75rem;
  color: var(--color-text);
  text-align: center;
  text-decoration: none;
  box-shadow: var(--shadow-sm);
  z-index: 50;
  display: none;
}

.return-btn::before {
  content: '↑';
  display: block;
  font-size: 1rem;
  color: var(--color-primary);
  margin-bottom: 0.25rem;
}

.return-btn:hover {
  border-color: var(--color-primary);
  text-decoration: none;
}

@media (min-width: 1190px) {
  .return-btn.visible {
    display: block;
  }
}

/* Mobile Back to Top Button */
.back-to-top {
  position: fixed;
  right: 1rem;
  bottom: 1.5rem;
  width: 48px;
  height: 48px;
  background: var(--color-primary);
  color: var(--color-bg);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 12px rgba(245, 73, 0, 0.3), 0 2px 4px rgba(0, 0, 0, 0.1);
  z-index: 50;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity 0.2s ease, visibility 0.2s ease, transform 0.2s ease, background 0.15s ease, color 0.15s ease;
}

.back-to-top:hover {
  background: var(--color-primary-dark);
  color: var(--color-white);
  text-decoration: none;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

@media (min-width: 1190px) {
  .back-to-top {
    display: none;
  }
}

/* Embed page overrides */
.embed-body {
  background: var(--color-white);
  padding: 1rem;
  min-height: auto;
}

.embed-container {
  max-width: 100%;
}

.embed-header {
  text-align: center;
  margin-bottom: 1rem;
}

.embed-header h1 {
  font-size: 1.125rem;
  margin: 0 0 0.25rem 0;
}

.embed-header p {
  font-size: 0.8125rem;
  color: var(--color-text-light);
  margin: 0;
}

.embed-footer {
  text-align: center;
  margin-top: 1.5rem;
  padding: 1rem;
}

.embed-footer a {
  display: inline-block;
  background: var(--color-primary);
  color: #fff;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 0.875rem;
  text-decoration: none;
  transition: background 0.2s ease;
}

.embed-footer a:hover {
  background: var(--color-primary-dark);
}

.embed-layout .callout {
  display: none;
}

/* 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: 0;
}

:focus:not(:focus-visible) {
  outline: none;
}

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

  html {
    scroll-behavior: auto;
  }
}

/* Print styles */
@media print {
  .header,
  .footer,
  .nav-toggle,
  .btn-copy,
  .embed-cta,
  .table-controls button,
  .return-btn {
    display: none !important;
  }

  body {
    background: var(--color-white);
  }

  section {
    page-break-inside: avoid;
  }
}