/* Splitpayments — single stylesheet, no frameworks, CSP-safe.
   Theming: every color is a token; @media (prefers-color-scheme: dark)
   overrides the tokens so the whole UI follows the OS setting. */

:root {
  color-scheme: light;
  --bg: #f4f5f7;
  --surface: #ffffff;
  --text: #1f2430;
  --muted: #6b7280;
  --border: #e2e5ea;
  --primary: #3b6ef6;
  --primary-dark: #2f56c4; /* hover state; a deeper primary in light mode */
  --primary-soft: #eef1fe;
  --primary-soft-hover: #dfe6fd;
  --focus-ring: #bcd0ff;
  --positive: #1a7f4f;
  --negative: #c0392b;
  --ok-bg: #eef8f1;
  --ok-border: #bfe5cc;
  --err-bg: #fdf0f0;
  --err-border: #f3c6c6;
  --danger-hover-bg: #fdf0f0;
  --payment-bg: #eef4ff;
  --payment-border: #c9dbff;
  --hero-gradient: linear-gradient(135deg, #f0faf4, #ffffff);
  --backdrop: rgba(15, 23, 42, 0.35);
  --shadow: 0 1px 3px rgba(16, 24, 40, 0.08);
  --radius: 10px;
}

@media (prefers-color-scheme: dark) {
  :root {
    color-scheme: dark;
    --bg: #12141a;
    --surface: #1a1d24;
    --text: #e6e8ee;
    --muted: #9aa1af;
    --border: #2a2f3a;
    --primary: #4a7dff;
    --primary-dark: #7ea2ff; /* hover state; brighter reads better on dark */
    --primary-soft: #22304f;
    --primary-soft-hover: #2a3a5f;
    --focus-ring: #3b5aa0;
    --positive: #34c48c;
    --negative: #ff7a66;
    --ok-bg: #122419;
    --ok-border: #1f5138;
    --err-bg: #2a1414;
    --err-border: #5f2b2b;
    --danger-hover-bg: #2e1717;
    --payment-bg: #1c2740;
    --payment-border: #2c3c63;
    --hero-gradient: linear-gradient(135deg, #12211a, #161a22);
    --backdrop: rgba(0, 0, 0, 0.6);
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.5);
  }
}

* { box-sizing: border-box; }

html { font-size: 16px; }

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
}

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

h1 { font-size: 1.5rem; margin: 0 0 0.25rem; }
h2 { font-size: 1.1rem; margin: 0; }
h3 { font-size: 0.95rem; margin: 0 0 0.35rem; }

/* App shell: full-height sidebar next to a topbar + content column */
.shell {
  display: flex;
  min-height: 100vh;
}
.main-col {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
}

/* Sidebar */
.sidebar {
  width: 230px;
  flex-shrink: 0;
  background: var(--surface);
  border-right: 1px solid var(--border);
  padding: 1rem 0.75rem calc(1rem + env(safe-area-inset-bottom));
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}
.sidenav { display: flex; flex-direction: column; gap: 0.15rem; }
.sidenav-link {
  color: var(--muted);
  font-weight: 500;
  padding: 0.4rem 0.6rem;
  border-radius: 8px;
}
.sidenav-link:hover { background: var(--bg); color: var(--text); text-decoration: none; }
.sidenav-link[aria-current="page"] { background: var(--primary-soft); color: var(--primary-dark); }

.sidenav-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 0.6rem;
  margin-bottom: 0.3rem;
}
.sidenav-title {
  color: var(--muted);
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.sidenav-list { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 0.1rem; }
.sidenav-item {
  display: block;
  color: var(--text);
  font-size: 0.92rem;
  padding: 0.35rem 0.6rem;
  border-radius: 8px;
  overflow-wrap: anywhere;
}
.sidenav-item:hover { background: var(--bg); text-decoration: none; }
.sidenav-item[aria-current="page"] { background: var(--primary-soft); color: var(--primary-dark); }
.sidenav-empty { color: var(--muted); font-size: 0.85rem; margin: 0.25rem 0 0; padding: 0 0.6rem; }

/* Sidebar "+" add buttons: a <details> drop-down form, no JS needed */
.nav-add { position: relative; }
.nav-add summary { list-style: none; }
.nav-add summary::-webkit-details-marker { display: none; }
.nav-add-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 1.45rem;
  height: 1.45rem;
  border-radius: 50%;
  background: var(--primary-soft);
  color: var(--primary-dark);
  font-weight: 700;
  line-height: 1;
  cursor: pointer;
  user-select: none;
}
.nav-add-btn:hover { background: var(--primary-soft-hover); }
.nav-add[open] .nav-add-btn { background: var(--primary); color: #fff; }
.nav-add-form {
  position: absolute;
  right: 0;
  top: calc(100% + 0.4rem);
  z-index: 20;
  width: 210px;
  padding: 0.6rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

/* Top bar */
.topbar {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 10;
}
.topbar-inner {
  max-width: 980px;
  margin: 0 auto;
  padding: 0.6rem 1rem;
  display: flex;
  align-items: center;
  gap: 1rem;
}
.brand {
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--text);
}
.brand:hover { text-decoration: none; color: var(--primary); }
.topbar-user { display: flex; align-items: center; gap: 0.6rem; margin-left: auto; }
.user-chip { color: var(--muted); font-size: 0.9rem; }
.nav-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text);
  font-size: 1.2rem;
  line-height: 1;
  padding: 0.25rem 0.4rem;
  cursor: pointer;
}
.backdrop { display: none; }

/* Mobile: the sidebar becomes an off-canvas drawer behind the ☰ toggle */
@media (max-width: 800px) {
  .sidebar {
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    z-index: 30;
    padding-top: calc(1rem + env(safe-area-inset-top));
    transform: translateX(-100%);
    transition: transform 0.2s ease;
    overflow-y: auto;
  }
  body.sidebar-open .sidebar {
    transform: none;
    box-shadow: 0 0 30px var(--backdrop);
  }
  .nav-toggle { display: inline-flex; }
  body.sidebar-open .backdrop {
    display: block;
    position: fixed;
    inset: 0;
    z-index: 25;
    background: var(--backdrop);
  }
}

/* Layout */
.container {
  max-width: 980px;
  margin: 0 auto;
  padding: 1.25rem 1rem 3rem;
}
.page-head {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 1rem;
  flex-wrap: wrap;
  margin-bottom: 1.1rem;
}
.page-actions { display: flex; gap: 0.5rem; align-items: center; flex-wrap: wrap; }
.grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-bottom: 1rem;
}
@media (max-width: 720px) {
  .grid-2 { grid-template-columns: 1fr; }
}

/* Cards & lists */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1rem 1.15rem;
  margin-bottom: 1rem;
}
.card-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.6rem;
}
.subhead { margin-top: 1rem; }

.list { list-style: none; margin: 0; padding: 0; }
.list-row {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.5rem 0;
  border-top: 1px solid var(--border);
}
.list-row:first-child { border-top: none; }
.list-col { display: flex; flex-direction: column; }
.list-main { color: var(--text); font-weight: 500; flex: 1; }
.list-sub { color: var(--muted); font-size: 0.85rem; }
.list-amount { margin-left: auto; font-variant-numeric: tabular-nums; white-space: nowrap; }

.positive { color: var(--positive); }
.negative { color: var(--negative); }

.tag {
  display: inline-block;
  background: var(--bg);
  border: 1px solid var(--border);
  color: var(--muted);
  border-radius: 999px;
  font-size: 0.7rem;
  padding: 0.05rem 0.5rem;
  vertical-align: middle;
}
.tag-payment { background: var(--payment-bg); color: var(--primary-dark); border-color: var(--payment-border); }

/* Balance hero */
.balance-hero {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 0.1rem;
  padding: 1.1rem 1.25rem;
}
.balance-hero.balanced { background: var(--hero-gradient); }
.balance-center {
  max-width: 420px;
  margin: 2.5rem auto 0;
  align-items: center;
  text-align: center;
}
.balance-label { color: var(--muted); font-size: 0.85rem; text-transform: uppercase; letter-spacing: 0.04em; }
.balance-big { font-weight: 600; font-size: 1.05rem; }
.balance-amount { font-size: 1.9rem; font-weight: 700; font-variant-numeric: tabular-nums; }

/* Buttons */
.btn {
  display: inline-block;
  border: 1px solid transparent;
  border-radius: 8px;
  padding: 0.45rem 0.95rem;
  font-size: 0.92rem;
  font-weight: 600;
  cursor: pointer;
  text-align: center;
  transition: background 0.15s ease;
}
.btn:hover { text-decoration: none; }
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-dark); color: #fff; }
.btn-secondary { background: var(--primary-soft); color: var(--primary-dark); }
.btn-secondary:hover { background: var(--primary-soft-hover); }
.btn-ghost { background: transparent; color: var(--primary); border-color: var(--border); }
.btn-ghost:hover { background: var(--bg); }
.btn-danger { background: transparent; color: var(--negative); border-color: var(--border); }
.btn-danger:hover { background: var(--danger-hover-bg); }
.btn-small { padding: 0.25rem 0.6rem; font-size: 0.82rem; }
.btn-block { width: 100%; }

/* Forms */
.field { margin-bottom: 0.85rem; display: flex; flex-direction: column; gap: 0.3rem; }
.field label { font-weight: 600; font-size: 0.88rem; }
.field label small { color: var(--muted); font-weight: 400; }
.field-check label { font-weight: 400; display: flex; gap: 0.5rem; align-items: center; }

input[type="text"], input[type="email"], input[type="password"], input[type="date"],
input[type="number"], input:not([type]), select, textarea {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.5rem 0.65rem;
  font: inherit;
  background: var(--surface);
  color: var(--text);
  width: 100%;
}
input:focus, select:focus, textarea:focus {
  outline: 2px solid var(--focus-ring);
  border-color: var(--primary);
}
textarea { resize: vertical; }

.row-form {
  display: flex;
  gap: 0.5rem;
  margin-top: 0.75rem;
}
.row-form input { flex: 1; }
.inline-form { display: inline; }

.form-error {
  background: var(--err-bg);
  border: 1px solid var(--err-border);
  color: var(--negative);
  border-radius: 8px;
  padding: 0.55rem 0.75rem;
  font-size: 0.9rem;
}
.form-hint { color: var(--muted); font-size: 0.9rem; }
.hint { color: var(--muted); font-size: 0.85rem; }
.muted { color: var(--muted); }
.notes { white-space: pre-wrap; }

/* Auth cards */
.auth-card {
  max-width: 420px;
  margin: 2.5rem auto;
}

/* Flash */
.flash {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  border-radius: 8px;
  padding: 0.6rem 0.9rem;
  margin-bottom: 1rem;
  font-size: 0.92rem;
  border: 1px solid;
  overflow-wrap: anywhere;
}
.flash-ok { background: var(--ok-bg); border-color: var(--ok-border); color: var(--positive); }
.flash-error { background: var(--err-bg); border-color: var(--err-border); color: var(--negative); }
.flash-close { color: inherit; font-weight: 700; font-size: 1rem; line-height: 1; }

/* Draft expense banner (group page) */
.draft-banner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
  border-radius: 8px;
  padding: 0.6rem 0.9rem;
  margin-bottom: 1rem;
  font-size: 0.92rem;
  border: 1px dashed var(--ok-border);
  background: var(--ok-bg);
  color: var(--positive);
}
.draft-banner-actions { display: flex; gap: 0.5rem; align-items: center; }

/* Tables */
.table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.93rem;
}
.table th, .table td {
  text-align: left;
  padding: 0.5rem 0.6rem;
  border-top: 1px solid var(--border);
}
.table thead th {
  border-top: none;
  color: var(--muted);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.03em;
}
.table .num { text-align: right; font-variant-numeric: tabular-nums; }
.table tfoot td { font-weight: 600; border-top: 2px solid var(--border); }
.row-payment { background: var(--payment-bg); }

/* Debts & settle */
.debts { list-style: none; margin: 0; padding: 0; color: var(--text); }
.debts li { padding: 0.3rem 0; font-size: 0.93rem; }
.settle-box { margin-top: 1rem; }
.settle-box summary {
  cursor: pointer;
  color: var(--primary);
  font-weight: 600;
  font-size: 0.92rem;
}
.settle-form { margin-top: 0.75rem; }
.settle-inline { display: inline; }

.settings-box { margin-top: 1rem; }
.settings-box summary { cursor: pointer; color: var(--primary); font-weight: 600; font-size: 0.92rem; }
.settings-box form { margin-top: 0.75rem; }

/* Activity */
.activity-list { list-style: none; margin: 0; padding: 0; }
.activity-row {
  display: flex;
  gap: 0.75rem;
  padding: 0.5rem 0;
  border-top: 1px solid var(--border);
  align-items: flex-start;
}
.activity-row:first-child { border-top: none; }
.activity-icon {
  width: 1.7rem;
  height: 1.7rem;
  border-radius: 50%;
  background: var(--bg);
  border: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  flex-shrink: 0;
}
.icon-payment_added { background: var(--payment-bg); border-color: var(--payment-border); }
.activity-body { display: flex; flex-direction: column; }
.activity-detail { font-size: 0.93rem; }
.activity-meta { color: var(--muted); font-size: 0.8rem; }

/* Expense form */
.expense-form .form-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0 1rem;
}
.expense-form .form-grid .span-2 { grid-column: span 2; }
@media (max-width: 640px) {
  .expense-form .form-grid { grid-template-columns: 1fr; }
  .expense-form .form-grid .span-2 { grid-column: span 1; }
}
fieldset {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.75rem 1rem 1rem;
  margin: 0 0 1rem;
}
legend { font-weight: 600; font-size: 0.88rem; padding: 0 0.35rem; }
.payer-fallback { display: flex; gap: 0.5rem; }
.checkbox-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 0.35rem 0.75rem;
}
.checkbox { display: flex; align-items: center; gap: 0.45rem; font-size: 0.93rem; }
.checkbox input { width: auto; }
.form-dynamic .mode-tabs { display: flex; gap: 0.4rem; flex-wrap: wrap; margin-bottom: 0.75rem; }
.mode-tab {
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--surface);
  color: var(--muted);
  padding: 0.3rem 0.85rem;
  font-size: 0.86rem;
  font-weight: 600;
  cursor: pointer;
}
.mode-tab[aria-pressed="true"] { background: var(--primary); border-color: var(--primary); color: #fff; }
.payer-row, .split-row {
  display: grid;
  grid-template-columns: minmax(120px, 1fr) minmax(110px, 160px) auto;
  gap: 0.5rem;
  align-items: center;
  margin-bottom: 0.45rem;
}
.split-row.split-even { grid-template-columns: auto 1fr; }
.payer-row .remove, .item-row .remove {
  background: none;
  border: none;
  color: var(--muted);
  font-size: 1rem;
  cursor: pointer;
  padding: 0.25rem;
}
.payer-row .remove:hover, .item-row .remove:hover { color: var(--negative); }
.add-link {
  background: none;
  border: none;
  color: var(--primary);
  font-weight: 600;
  cursor: pointer;
  padding: 0.25rem 0;
  font-size: 0.88rem;
}
.remaining-ok { color: var(--positive); }
.remaining-bad { color: var(--negative); }
.form-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  margin-top: 0.5rem;
}
.item-table { width: 100%; border-collapse: collapse; margin-bottom: 0.5rem; }
.item-table th { text-align: left; font-size: 0.78rem; color: var(--muted); padding: 0.2rem 0.3rem; }
.item-table td { padding: 0.2rem 0.3rem; }
.item-people { display: flex; flex-wrap: wrap; gap: 0.15rem 0.6rem; }
.item-people .checkbox { font-size: 0.84rem; }

/* Receipt scan */
.scan-buttons { display: flex; gap: 0.6rem; flex-wrap: wrap; }
.scan-buttons .btn { position: relative; overflow: hidden; }
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  opacity: 0;
  pointer-events: none;
}
.scan-preview {
  max-width: 100%;
  max-height: 320px;
  border-radius: 8px;
  border: 1px solid var(--border);
  margin-top: 0.6rem;
}
.receipt-image { max-width: 100%; max-height: 480px; border-radius: 8px; border: 1px solid var(--border); }

/* Confirm dialog */
dialog.confirm-dialog {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--text);
  box-shadow: 0 8px 30px var(--backdrop);
  padding: 1.1rem 1.25rem;
  max-width: 340px;
}
dialog.confirm-dialog::backdrop { background: var(--backdrop); }
.confirm-buttons {
  display: flex;
  justify-content: flex-end;
  gap: 0.5rem;
  margin-top: 0.9rem;
}

/* Error page */
.error-card { text-align: center; }
.error-card .btn { margin-top: 0.75rem; }