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

:root {
  --primary:       #3B82F6;
  --primary-dark:  #2563EB;
  --danger:        #EF4444;
  --success:       #10B981;
  --bg:            #F3F4F6;
  --card:          #FFFFFF;
  --border:        #E5E7EB;
  --text:          #111827;
  --muted:         #6B7280;
  --radius:        8px;
  --shadow:        0 1px 3px rgba(0,0,0,.10), 0 1px 2px rgba(0,0,0,.06);
}

body {
  font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
  min-height: 100vh;
}

/* ── Page shell ─────────────────────────────────────────────────────────────── */
.page {
  max-width: 1100px;
  margin: 0 auto;
  padding: 1.5rem;
}

.page-header {
  margin-bottom: 1.75rem;
}

.page-header-main {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: .5rem;
}

.page-header h1 {
  font-size: 1.75rem;
  font-weight: 700;
  letter-spacing: -.02em;
}

.back-link {
  display: inline-block;
  color: var(--primary);
  text-decoration: none;
  font-size: .875rem;
  margin-bottom: .5rem;
}
.back-link:hover { text-decoration: underline; }

.people-tags {
  display: flex;
  flex-wrap: wrap;
  gap: .375rem;
  margin-top: .5rem;
}

.tag {
  background: #EFF6FF;
  color: var(--primary);
  padding: .2rem .65rem;
  border-radius: 999px;
  font-size: .78rem;
  font-weight: 500;
}

/* ── Layout ─────────────────────────────────────────────────────────────────── */
.content {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

/* ── Cards ──────────────────────────────────────────────────────────────────── */
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1.25rem;
}

.card h2 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 1rem;
  padding-bottom: .75rem;
  border-bottom: 1px solid var(--border);
}

/* ── Buttons ────────────────────────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: .5rem 1.1rem;
  border: none;
  border-radius: var(--radius);
  font-size: .875rem;
  font-weight: 500;
  cursor: pointer;
  transition: background .15s, opacity .15s;
  white-space: nowrap;
}
.btn:disabled { opacity: .5; cursor: default; }

.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover:not(:disabled) { background: var(--primary-dark); }

.btn-secondary { background: var(--border); color: var(--text); }
.btn-secondary:hover:not(:disabled) { background: #D1D5DB; }

.btn-sm { padding: .3rem .75rem; font-size: .8rem; }

.btn-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: none;
  border: none;
  color: var(--muted);
  cursor: pointer;
  font-size: 1.1rem;
  width: 1.75rem;
  height: 1.75rem;
  border-radius: 4px;
  line-height: 1;
  transition: color .15s, background .15s;
  flex-shrink: 0;
}
.btn-icon:hover { color: var(--danger); background: #FEF2F2; }

/* ── Forms ──────────────────────────────────────────────────────────────────── */
.form-group {
  display: flex;
  flex-direction: column;
  gap: .35rem;
  flex: 1;
}

.form-group label {
  font-size: .8rem;
  font-weight: 600;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: .04em;
}

input[type="text"],
input[type="number"],
select {
  padding: .5rem .75rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: .875rem;
  width: 100%;
  background: #fff;
  color: var(--text);
  transition: border-color .15s, box-shadow .15s;
  appearance: auto;
}

input:focus, select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(59,130,246,.15);
}

.form-row {
  display: flex;
  gap: 1rem;
  margin-bottom: 1rem;
}

.amount-group { flex: 0 0 130px !important; }

@media (max-width: 580px) {
  .form-row       { flex-direction: column; }
  .amount-group   { flex: 1 !important; }
}

/* ── New trip – people input ────────────────────────────────────────────────── */
.people-builder {
  display: flex;
  flex-direction: column;
  gap: .4rem;
  margin-bottom: .6rem;
}

.person-entry {
  display: flex;
  align-items: center;
  gap: .4rem;
}

.person-entry .person-input { flex: 1; }

.person-size-wrap {
  display: flex;
  align-items: center;
  gap: .2rem;
  flex-shrink: 0;
}

.size-x {
  font-size: .8rem;
  color: var(--muted);
}

.person-size {
  width: 3.5rem !important;
  text-align: center;
}

.tag-size {
  opacity: .65;
  font-size: .85em;
}

.balance-size {
  font-size: .8em;
  color: var(--muted);
}

/* ── People editor ──────────────────────────────────────────────────────────── */
.people-edit-list {
  display: flex;
  flex-direction: column;
  gap: .4rem;
  margin-bottom: .75rem;
}

.person-edit-row {
  display: flex;
  align-items: center;
  gap: .4rem;
}

.venmo-input-wrap {
  display: flex;
  align-items: center;
  gap: .2rem;
  flex-shrink: 0;
}

.venmo-prefix {
  font-size: .8rem;
  color: var(--muted);
}

.person-edit-handle {
  width: 100px !important;
  font-size: .8rem;
}

.person-add-row {
  display: flex;
  align-items: center;
  gap: .4rem;
  padding-top: .75rem;
  border-top: 1px solid var(--border);
}

.people-editor-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding-top: .75rem;
  margin-top: .25rem;
  border-top: 1px solid var(--border);
}

.people-editor-footer .error-msg { padding: 0; }

/* ── Trips list ─────────────────────────────────────────────────────────────── */
.trips-grid {
  display: flex;
  flex-direction: column;
  gap: .5rem;
}

.trip-card {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: .875rem 1rem;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  text-decoration: none;
  color: inherit;
  transition: border-color .15s, box-shadow .15s;
}
.trip-card:hover { border-color: var(--primary); box-shadow: var(--shadow); }

.trip-card-name { font-weight: 600; }
.trip-card-meta { font-size: .8rem; color: var(--muted); margin-top: .15rem; }
.trip-card-arrow { color: var(--muted); font-size: 1.1rem; }

/* ── Paid-for selector ──────────────────────────────────────────────────────── */
.radio-group {
  display: flex;
  gap: .75rem;
  flex-wrap: wrap;
}

.radio-group label {
  display: flex;
  align-items: center;
  gap: .35rem;
  font-size: .875rem;
  font-weight: 400;
  color: var(--text);
  cursor: pointer;
  text-transform: none;
  letter-spacing: 0;
}

.radio-group input[type="radio"] { margin: 0; cursor: pointer; }

.people-checklist {
  margin-top: .75rem;
  display: flex;
  flex-wrap: wrap;
  gap: .4rem;
}
.people-checklist.hidden { display: none; }

.checklist-hint {
  width: 100%;
  font-size: .78rem;
  color: var(--muted);
  margin-bottom: .15rem;
}

.check-pill {
  display: inline-flex;
  align-items: center;
  gap: .35rem;
  padding: .25rem .7rem;
  border: 1px solid var(--border);
  border-radius: 999px;
  font-size: .8rem;
  cursor: pointer;
  background: var(--bg);
  transition: border-color .15s, background .15s, color .15s;
  user-select: none;
}
.check-pill input { margin: 0; display: none; }
.check-pill:hover { border-color: var(--primary); background: #EFF6FF; }
.check-pill.checked {
  background: #EFF6FF;
  border-color: var(--primary);
  color: var(--primary);
  font-weight: 500;
}

/* ── Expense list ───────────────────────────────────────────────────────────── */
.expense-list { display: flex; flex-direction: column; }

.expense-row {
  display: flex;
  align-items: flex-start;
  gap: .75rem;
  padding: .75rem 0;
  border-bottom: 1px solid var(--border);
}
.expense-row:last-child { border-bottom: none; }

.expense-info  { flex: 1; min-width: 0; }
.expense-desc  { font-weight: 500; }
.expense-meta  { font-size: .78rem; color: var(--muted); margin-top: .1rem; }

.expense-right {
  display: flex;
  align-items: center;
  gap: .4rem;
  flex-shrink: 0;
}

.expense-amount { font-weight: 700; font-size: .95rem; }

.empty-state { font-size: .875rem; color: var(--muted); }

/* ── Settlement ─────────────────────────────────────────────────────────────── */
.settlement-card h2 { margin-bottom: .75rem; }

.settlement-body {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.settlement-section { }

.settlement-label {
  font-size: .72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .06em;
  color: var(--muted);
  margin-bottom: .5rem;
}

/* Breakdown table */
.breakdown-table {
  width: 100%;
  table-layout: fixed;
  border-collapse: collapse;
  font-size: .875rem;
}

.breakdown-table th:first-child,
.breakdown-table td:first-child {
  width: 14%;
}

.breakdown-table th {
  text-align: left;
  font-size: .72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .05em;
  color: var(--muted);
  padding: .3rem 1rem .3rem 0;
  border-bottom: 1px solid var(--border);
}

.breakdown-table td {
  padding: .45rem 1rem .45rem 0;
  border-bottom: 1px solid var(--border);
  vertical-align: middle;
}

.breakdown-table tbody tr:last-child td { border-bottom: none; }
.breakdown-table th.col-num,
.breakdown-table td.col-num {
  text-align: right;
  padding-right: 0;
  font-variant-numeric: tabular-nums;
}

.balance-amt   { font-weight: 600; }
.balance-size  { font-size: .8em; color: var(--muted); }
.amt-pos       { color: var(--success); }
.amt-neg       { color: var(--danger); }
.amt-zero      { color: var(--muted); }

/* Payments */
.payments-list {
  display: grid;
  grid-template-columns: auto auto auto auto auto;
  column-gap: .45rem;
  row-gap: .35rem;
  align-items: center;
}

.payment-row { display: contents; }
.payment-row > * { font-size: .875rem; }

.pay-from  { font-weight: 500; }
.pay-arrow { color: var(--muted); }
.pay-to    { font-weight: 500; }
.pay-amt   { font-weight: 700; }

.pay-action { flex-shrink: 0; font-size: .78rem; }

.pay-action-venmo {
  padding: .2rem .6rem;
  background: #008CFF;
  color: #fff;
  border-radius: 999px;
  text-decoration: none;
  font-weight: 500;
  transition: opacity .15s;
  text-align: center;
}
.pay-action-venmo:hover { opacity: .85; }

.pay-action-missing {
  color: var(--muted);
  font-style: italic;
}

.pay-action-add-venmo {
  background: none;
  border: none;
  padding: 0;
  color: var(--primary);
  font-size: .78rem;
  cursor: pointer;
  text-decoration: underline;
  text-underline-offset: 2px;
}
.pay-action-add-venmo:hover { color: var(--primary-dark); }

.all-settled {
  font-size: .875rem;
  color: var(--success);
  font-weight: 500;
}

/* ── Expense list footer ────────────────────────────────────────────────────── */
.expense-list-footer {
  margin-top: 1rem;
  padding-top: .75rem;
  border-top: 1px solid var(--border);
}

/* ── Modal ──────────────────────────────────────────────────────────────────── */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, .45);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
  padding: 1rem;
}

.modal {
  background: var(--card);
  border-radius: var(--radius);
  box-shadow: 0 20px 60px rgba(0, 0, 0, .25);
  width: 100%;
  max-width: 520px;
  max-height: 90vh;
  overflow-y: auto;
  padding: 1.5rem;
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.25rem;
  padding-bottom: .75rem;
  border-bottom: 1px solid var(--border);
}

.modal-header h2 {
  font-size: 1rem;
  font-weight: 600;
  margin: 0;
  padding: 0;
  border: none;
}

/* ── Misc ───────────────────────────────────────────────────────────────────── */
.error-msg {
  color: var(--danger);
  font-size: .875rem;
  padding: .4rem 0;
}

.loading { color: var(--muted); padding: 2rem; text-align: center; }