/* ── Design Tokens ───────────────────────────────────────────────────────── */
:root {
  --clr-primary:        #4F46E5;
  --clr-primary-hover:  #4338CA;
  --clr-primary-light:  #EEF2FF;
  --clr-success:        #059669;
  --clr-success-bg:     #ECFDF5;
  --clr-danger:         #DC2626;
  --clr-danger-bg:      #FEF2F2;
  --clr-warning:        #D97706;
  --clr-warning-bg:     #FFFBEB;

  --clr-bg:             #F8FAFC;
  --clr-surface:        #FFFFFF;
  --clr-border:         #E2E8F0;
  --clr-border-strong:  #CBD5E1;

  --clr-text:           #0F172A;
  --clr-text-muted:     #64748B;
  --clr-text-light:     #94A3B8;

  --radius-sm:  6px;
  --radius-md:  10px;
  --radius-lg:  16px;
  --radius-xl:  24px;

  --shadow-sm:  0 1px 3px rgba(0,0,0,.06), 0 1px 2px rgba(0,0,0,.04);
  --shadow-md:  0 4px 8px rgba(0,0,0,.07), 0 2px 4px rgba(0,0,0,.04);
  --shadow-lg:  0 12px 24px rgba(0,0,0,.08), 0 4px 8px rgba(0,0,0,.04);
  --shadow-modal: 0 20px 60px rgba(0,0,0,.18);

  --header-h:   60px;
  --container-max: 1400px;
  --gap:        1.25rem;
}

/* ── Reset ───────────────────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; -webkit-text-size-adjust: 100%; }
body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, sans-serif;
  background: var(--clr-bg);
  color: var(--clr-text);
  line-height: 1.5;
  min-height: 100dvh;
  overflow: hidden; /* views handle their own scroll */
}
img, svg { display: block; max-width: 100%; }
button { cursor: pointer; font: inherit; border: none; background: none; }
input, select, textarea { font: inherit; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }

/* ── Accessibility ────────────────────────────────────────────────────────── */
.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0;
  margin: -1px; overflow: hidden; clip: rect(0,0,0,0); border: 0;
}
:focus-visible { outline: 2px solid var(--clr-primary); outline-offset: 2px; }

/* ── Layout ──────────────────────────────────────────────────────────────── */
#app { height: 100dvh; position: relative; }

.view {
  display: none;
  height: 100dvh;
  overflow-y: auto;
  overflow-x: hidden;
  -webkit-overflow-scrolling: touch;
}
.view.active { display: block; }

.container {
  width: 100%;
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: 1rem;
}

/* ── Typography ──────────────────────────────────────────────────────────── */
h1 { font-size: clamp(1.25rem, 2.5vw, 1.75rem); font-weight: 700; }
h2 { font-size: clamp(1.1rem, 2vw, 1.35rem); font-weight: 700; }
h3 { font-size: 1rem; font-weight: 600; }
.text-muted { color: var(--clr-text-muted); }

/* ── Page Header ─────────────────────────────────────────────────────────── */
.page-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: var(--clr-surface);
  border-bottom: 1px solid var(--clr-border);
  box-shadow: var(--shadow-sm);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  height: var(--header-h);
}

/* ── Brand ───────────────────────────────────────────────────────────────── */
.brand { display: flex; align-items: center; gap: .6rem; }
.brand-icon {
  width: 36px; height: 36px;
  background: var(--clr-primary);
  color: #fff;
  border-radius: var(--radius-md);
  display: grid; place-items: center;
  font-weight: 800; font-size: 1.1rem;
}
.brand-name { font-size: 1.35rem; font-weight: 800; letter-spacing: -.02em; }
.header-actions { display: flex; align-items: center; gap: .5rem; }

/* ── Buttons ─────────────────────────────────────────────────────────────── */
.btn {
  display: inline-flex; align-items: center; gap: .4rem;
  padding: .5rem 1.1rem;
  border-radius: var(--radius-md);
  font-weight: 600; font-size: .875rem;
  transition: background .15s, color .15s, box-shadow .15s, opacity .15s;
  white-space: nowrap;
}
.btn:disabled { opacity: .5; cursor: not-allowed; }

.btn-primary {
  background: var(--clr-primary); color: #fff;
  box-shadow: 0 1px 2px rgba(79,70,229,.3);
}
.btn-primary:hover:not(:disabled) { background: var(--clr-primary-hover); }

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

.btn-ghost {
  background: transparent; color: var(--clr-text-muted);
}
.btn-ghost:hover { background: var(--clr-bg); color: var(--clr-text); }

.btn-danger {
  background: var(--clr-danger); color: #fff;
}
.btn-danger:hover:not(:disabled) { background: #b91c1c; }

.btn-sm { padding: .35rem .75rem; font-size: .8rem; }
.btn-lg { padding: .75rem 1.75rem; font-size: 1rem; }

.btn-icon-close {
  width: 28px; height: 28px;
  border-radius: 50%;
  display: grid; place-items: center;
  font-size: .8rem; color: var(--clr-text-muted);
  transition: background .15s, color .15s;
}
.btn-icon-close:hover { background: var(--clr-danger-bg); color: var(--clr-danger); }

.btn-text-danger {
  font-size: .8rem; font-weight: 600; color: var(--clr-danger);
  padding: .2rem .4rem; border-radius: var(--radius-sm);
  transition: background .15s;
}
.btn-text-danger:hover { background: var(--clr-danger-bg); }

.btn-text-primary {
  font-size: .8rem; font-weight: 600; color: var(--clr-primary);
  padding: .2rem .4rem; border-radius: var(--radius-sm);
  transition: background .15s;
}
.btn-text-primary:hover { background: var(--clr-primary-light); }

.btn-icon-edit {
  width: 28px; height: 28px; border-radius: 50%;
  display: grid; place-items: center;
  font-size: .9rem; color: var(--clr-text-muted);
  transition: background .15s, color .15s;
  flex-shrink: 0;
}
.btn-icon-edit:hover { background: var(--clr-primary-light); color: var(--clr-primary); }

.btn-back {
  display: inline-flex; align-items: center; gap: .3rem;
  padding: .4rem .75rem; border-radius: var(--radius-md);
  font-size: .875rem; font-weight: 600; color: var(--clr-text-muted);
  transition: background .15s, color .15s;
}
.btn-back:hover { background: var(--clr-bg); color: var(--clr-text); }

.btn-text-sm {
  font-size: .8rem; color: var(--clr-primary); font-weight: 600;
  padding: .15rem .4rem; border-radius: var(--radius-sm);
  transition: background .15s;
}
.btn-text-sm:hover { background: var(--clr-primary-light); }

/* ── Forms ───────────────────────────────────────────────────────────────── */
.form-group { display: flex; flex-direction: column; gap: .4rem; }
.form-group label { font-size: .875rem; font-weight: 600; color: var(--clr-text); }

input[type="text"], input[type="number"], input[type="date"],
select, textarea {
  width: 100%;
  padding: .6rem .85rem;
  border: 1.5px solid var(--clr-border);
  border-radius: var(--radius-md);
  font-size: .9rem;
  color: var(--clr-text);
  background: var(--clr-surface);
  transition: border-color .15s, box-shadow .15s;
}
input:focus, select:focus, textarea:focus {
  outline: none;
  border-color: var(--clr-primary);
  box-shadow: 0 0 0 3px rgba(79,70,229,.12);
}

.input-prefix-wrap { position: relative; display: flex; align-items: center; }
.input-prefix {
  position: absolute; left: .85rem;
  font-weight: 600; color: var(--clr-text-muted); pointer-events: none;
}
.input-prefix-wrap input { padding-left: 2rem; }

.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
.modal-form { display: flex; flex-direction: column; gap: 1.1rem; }
.form-actions {
  display: flex; justify-content: flex-end; gap: .6rem;
  padding-top: .5rem;
}

.checkbox-group {
  display: flex; flex-wrap: wrap; gap: .5rem;
  padding: .75rem;
  border: 1.5px solid var(--clr-border);
  border-radius: var(--radius-md);
  background: var(--clr-bg);
}
.checkbox-label {
  display: flex; align-items: center; gap: .45rem;
  font-size: .875rem; cursor: pointer;
  padding: .3rem .6rem;
  border-radius: var(--radius-sm);
  transition: background .15s;
}
.checkbox-label:hover { background: var(--clr-primary-light); }
.checkbox-label input[type="checkbox"] { accent-color: var(--clr-primary); width: 15px; height: 15px; }

/* ── Modal ───────────────────────────────────────────────────────────────── */
.modal-overlay {
  position: fixed; inset: 0; z-index: 100;
  background: rgba(15,23,42,.45);
  backdrop-filter: blur(3px);
  display: grid; place-items: center;
  padding: 1rem;
  opacity: 0; pointer-events: none;
  transition: opacity .2s;
}
.modal-overlay.active { opacity: 1; pointer-events: all; }

.modal-box {
  background: var(--clr-surface);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-modal);
  width: 100%; max-width: 500px;
  max-height: 90dvh;
  overflow-y: auto;
  padding: 1.75rem;
  transform: translateY(10px);
  transition: transform .2s;
}
.modal-overlay.active .modal-box { transform: translateY(0); }

.modal-header {
  display: flex; align-items: center; justify-content: space-between;
  margin-bottom: 1.25rem;
}
.modal-header h2 { font-size: 1.2rem; }

.confirm-dialog { display: flex; flex-direction: column; gap: 1.25rem; }
.confirm-message { font-size: .95rem; line-height: 1.6; }
.confirm-actions { display: flex; justify-content: flex-end; gap: .6rem; }

/* ── Toast ───────────────────────────────────────────────────────────────── */
.toast-container {
  position: fixed; bottom: 1.5rem; right: 1.5rem; z-index: 200;
  display: flex; flex-direction: column; gap: .5rem;
}
.toast {
  padding: .7rem 1.2rem;
  border-radius: var(--radius-md);
  font-size: .875rem; font-weight: 600;
  box-shadow: var(--shadow-md);
  cursor: pointer;
  max-width: 320px;
  opacity: 0; transform: translateX(20px);
  transition: opacity .2s, transform .2s;
}
.toast-visible { opacity: 1; transform: translateX(0); }
.toast-success { background: var(--clr-success); color: #fff; }
.toast-error   { background: var(--clr-danger);  color: #fff; }
.toast-info    { background: var(--clr-text);     color: #fff; }
.toast-warning { background: var(--clr-warning);  color: #fff; }

/* ── Currency tag ────────────────────────────────────────────────────────── */
.currency-tag {
  display: inline-block;
  padding: .2rem .6rem;
  background: var(--clr-primary-light);
  color: var(--clr-primary);
  border-radius: var(--radius-sm);
  font-size: .78rem; font-weight: 700; letter-spacing: .04em;
}

/* ── Empty states ────────────────────────────────────────────────────────── */
.empty-state {
  display: flex; flex-direction: column; align-items: center; gap: 1rem;
  text-align: center;
  padding: 5rem 1rem;
}
.empty-icon { font-size: 3.5rem; color: var(--clr-text-light); }
.empty-state h2 { color: var(--clr-text); }
.empty-state p { color: var(--clr-text-muted); max-width: 30ch; }
.empty-state-sm {
  padding: 3rem 1rem; text-align: center; color: var(--clr-text-muted);
}
.empty-state-sm p { margin-bottom: .4rem; }

/* ─────────────────────────────────────────────────────────────────────────
   HOME PAGE
   ───────────────────────────────────────────────────────────────────────── */
.home-action-bar {
  background: var(--clr-surface);
  border-bottom: 1px solid var(--clr-border);
  padding: .375rem 0;
}
.home-action-bar .container {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: .5rem;
}
.home-action-bar .btn {
  border: 1px solid var(--clr-border-strong);
  color: var(--clr-text);
}
.home-action-bar .btn:hover {
  background: var(--clr-bg);
  border-color: var(--clr-border-strong);
}

.home-main { padding-top: 2rem; padding-bottom: 3rem; }

.section-header {
  display: flex; align-items: center; gap: .75rem;
  margin-bottom: 1.25rem;
}
.section-title { font-size: 1.15rem; }
.count-badge {
  background: var(--clr-primary); color: #fff;
  border-radius: 999px;
  padding: .1rem .55rem;
  font-size: .78rem; font-weight: 700;
}

/* Groups grid */
.groups-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: var(--gap);
}

/* Group card */
.group-card {
  background: var(--clr-surface);
  border: 1.5px solid var(--clr-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  padding: 1.25rem;
  display: flex; flex-direction: column; gap: .9rem;
  cursor: pointer;
  transition: box-shadow .18s, border-color .18s, transform .18s;
}
.group-card:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--clr-primary);
  transform: translateY(-2px);
}

.group-card-top {
  display: flex; justify-content: space-between; align-items: flex-start;
}
.group-avatar {
  width: 48px; height: 48px;
  background: var(--clr-primary-light);
  color: var(--clr-primary);
  border-radius: var(--radius-md);
  display: grid; place-items: center;
  font-weight: 800; font-size: 1.1rem; letter-spacing: .02em;
}
.group-card-name {
  font-size: 1.05rem; font-weight: 700;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.group-card-meta {
  font-size: .8rem; color: var(--clr-text-muted);
  display: flex; align-items: center; gap: .35rem;
}
.dot { color: var(--clr-text-light); }
.group-card-footer {
  display: flex; align-items: flex-end; justify-content: space-between;
  padding-top: .5rem;
  border-top: 1px solid var(--clr-border);
}
.total-label { font-size: .75rem; color: var(--clr-text-muted); margin-bottom: .15rem; }
.total-value { font-size: 1.1rem; font-weight: 700; }

/* ─────────────────────────────────────────────────────────────────────────
   GROUP PAGE
   ───────────────────────────────────────────────────────────────────────── */
.group-page { display: flex; flex-direction: column; min-height: 100dvh; }

.group-title-wrap {
  display: flex; align-items: center; gap: .75rem; flex: 1; justify-content: center;
  overflow: hidden;
}
.group-page-title {
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
  font-size: clamp(1rem, 2vw, 1.35rem);
}

/* People strip */
.people-strip-wrap {
  background: var(--clr-surface);
  border-bottom: 1px solid var(--clr-border);
  padding-block: .7rem;
}
.people-strip-row {
  display: flex; align-items: center; gap: .75rem; flex-wrap: wrap;
}
.people-label { font-size: .8rem; font-weight: 600; color: var(--clr-text-muted); flex-shrink: 0; }
.people-strip { display: flex; flex-wrap: wrap; gap: .45rem; align-items: center; flex: 1; }

.person-chip {
  display: inline-flex; align-items: center; gap: .3rem;
  padding: .3rem .7rem;
  background: var(--clr-primary-light);
  color: var(--clr-primary);
  border-radius: 999px;
  font-size: .82rem; font-weight: 600;
  white-space: nowrap;
}
.chip-action {
  width: 16px; height: 16px; border-radius: 50%;
  display: grid; place-items: center;
  font-size: .75rem;
  transition: background .15s;
  line-height: 1; flex-shrink: 0;
}
.chip-edit-btn { color: var(--clr-primary); }
.chip-edit-btn:hover { background: rgba(79,70,229,.25); }
.chip-remove { color: var(--clr-primary); }
.chip-remove:hover { background: rgba(220,38,38,.2); color: var(--clr-danger); }
.chip-add {
  background: var(--clr-bg);
  border: 1.5px dashed var(--clr-border-strong);
  color: var(--clr-text-muted);
  cursor: pointer;
  transition: border-color .15s, color .15s;
}
.chip-add:hover { border-color: var(--clr-primary); color: var(--clr-primary); }

/* Tab bar */
.tab-bar-wrap {
  background: var(--clr-surface);
  border-bottom: 1px solid var(--clr-border);
  position: sticky;
  top: var(--header-h);
  z-index: 10;
}
.tab-bar {
  display: flex; gap: 0;
}
.tab-btn {
  flex: 1;
  padding: .8rem .5rem;
  font-size: .875rem; font-weight: 600;
  color: var(--clr-text-muted);
  border-bottom: 2px solid transparent;
  transition: color .15s, border-color .15s;
  text-align: center;
}
.tab-btn:hover { color: var(--clr-primary); }
.tab-btn.active {
  color: var(--clr-primary);
  border-bottom-color: var(--clr-primary);
}

/* Tab content */
.tab-content { flex: 1; }
.tab-panel-inner {
  padding-top: 1.5rem;
  padding-bottom: 3rem;
}

/* ─────────────────────────────────────────────────────────────────────────
   EXPENSES TAB
   ───────────────────────────────────────────────────────────────────────── */
.expenses-toolbar {
  display: flex; align-items: center; justify-content: space-between;
  margin-bottom: 1.5rem; gap: 1rem; flex-wrap: wrap;
}
.total-card {
  display: flex; flex-direction: column;
}
.total-card .total-label { font-size: .8rem; color: var(--clr-text-muted); }
.total-card .total-amount { font-size: 1.5rem; font-weight: 800; color: var(--clr-text); }

.expense-list { display: flex; flex-direction: column; gap: .75rem; }

.expense-row {
  background: var(--clr-surface);
  border: 1.5px solid var(--clr-border);
  border-radius: var(--radius-md);
  padding: 1rem 1.1rem;
  transition: box-shadow .15s, border-color .15s;
}
.expense-row:hover { border-color: var(--clr-border-strong); box-shadow: var(--shadow-sm); }

.expense-row-main {
  display: flex; align-items: flex-start; justify-content: space-between;
  gap: .75rem; margin-bottom: .5rem;
}
.expense-info { display: flex; flex-direction: column; gap: .15rem; flex: 1; min-width: 0; }
.expense-title {
  font-weight: 700; font-size: .95rem;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.expense-split-hint { font-size: .78rem; color: var(--clr-text-muted); }
.expense-right { display: flex; flex-direction: column; align-items: flex-end; gap: .1rem; flex-shrink: 0; }
.expense-amount { font-size: 1.05rem; font-weight: 800; }
.expense-paid-by { font-size: .78rem; color: var(--clr-text-muted); }

.expense-row-foot {
  display: flex; align-items: center; justify-content: space-between;
  padding-top: .5rem;
  border-top: 1px solid var(--clr-border);
}
.expense-date { font-size: .8rem; color: var(--clr-text-muted); }
.expense-actions { display: flex; align-items: center; gap: .25rem; }

/* Header spacer keeps title centered */
.header-spacer { width: 80px; flex-shrink: 0; }

/* ─────────────────────────────────────────────────────────────────────────
   SETTLE TAB
   ───────────────────────────────────────────────────────────────────────── */
.settle-section { margin-bottom: 2rem; }
.settle-section-title {
  font-size: .9rem; font-weight: 700;
  text-transform: uppercase; letter-spacing: .07em;
  color: var(--clr-text-muted);
  margin-bottom: 1rem;
}

.balance-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: .75rem; }
.balance-card {
  background: var(--clr-surface);
  border: 1.5px solid var(--clr-border);
  border-radius: var(--radius-md);
  padding: 1rem 1.1rem;
  display: flex; flex-direction: column; gap: .3rem;
}
.balance-card.balance-positive { border-color: var(--clr-success); background: var(--clr-success-bg); }
.balance-card.balance-negative { border-color: var(--clr-danger);  background: var(--clr-danger-bg);  }
.balance-name { font-weight: 700; font-size: .95rem; }
.balance-label { font-size: .8rem; color: var(--clr-text-muted); }
.balance-amount { font-size: 1.2rem; font-weight: 800; margin-top: .25rem; }
.balance-amount.balance-positive { color: var(--clr-success); }
.balance-amount.balance-negative { color: var(--clr-danger); }
.balance-amount.balance-zero     { color: var(--clr-text-muted); }

.payments-list { display: flex; flex-direction: column; gap: .6rem; }

.payment-row {
  display: flex; align-items: center; justify-content: space-between;
  gap: .75rem;
  background: var(--clr-surface);
  border: 1.5px solid var(--clr-border);
  border-radius: var(--radius-md);
  padding: .85rem 1.1rem;
  flex-wrap: wrap;
  transition: border-color .15s, box-shadow .15s;
}
.payment-info { display: flex; align-items: center; gap: .6rem; flex-wrap: wrap; }
.payment-row-right { display: flex; align-items: center; gap: .75rem; flex-shrink: 0; }

/* Pending payment row — subtle amber left border */
.payment-pending {
  border-left: 3px solid var(--clr-warning);
}
.payment-pending:hover { box-shadow: var(--shadow-sm); border-color: var(--clr-warning); }

/* Settled payment row — green left border, muted */
.payment-settled {
  border-left: 3px solid var(--clr-success);
  background: var(--clr-success-bg);
  opacity: .85;
}
.payment-settled-name { color: var(--clr-text-muted); font-weight: 600; }
.payment-settled-amount { color: var(--clr-success); font-weight: 700; }
.settled-date { font-size: .75rem; color: var(--clr-text-light); }
.settled-check { color: var(--clr-success); font-size: 1rem; font-weight: 800; }

.payment-from, .payment-to { font-weight: 700; font-size: .95rem; }
.payment-arrow { color: var(--clr-text-muted); font-size: .9rem; }
.payment-amount { font-weight: 800; font-size: 1rem; color: var(--clr-primary); }

/* Mark as Paid button */
.btn-settle {
  background: var(--clr-success);
  color: #fff;
  padding: .35rem .85rem;
  font-size: .8rem; font-weight: 700;
  border-radius: var(--radius-md);
  white-space: nowrap;
  transition: background .15s, transform .1s;
}
.btn-settle:hover { background: #047857; transform: translateY(-1px); }
.btn-settle:active { transform: translateY(0); }

.settled-message { color: var(--clr-success); font-weight: 600; padding: 1rem 0; }

/* ── Snackbar ─────────────────────────────────────────────────────────────── */
.snackbar-container {
  position: fixed; bottom: 1.5rem; left: 50%; transform: translateX(-50%);
  z-index: 300; pointer-events: none;
  display: flex; flex-direction: column; align-items: center; gap: .5rem;
}
.snackbar {
  display: flex; align-items: center; justify-content: space-between;
  gap: 1rem;
  background: #1E293B;
  color: #fff;
  border-radius: var(--radius-lg);
  padding: .85rem 1.1rem .7rem;
  box-shadow: var(--shadow-lg);
  min-width: 280px; max-width: min(520px, calc(100vw - 2rem));
  pointer-events: all;
  opacity: 0; transform: translateY(12px);
  transition: opacity .25s, transform .25s;
  overflow: hidden;
  position: relative;
}
.snackbar-show { opacity: 1; transform: translateY(0); }

.snackbar-message { font-size: .9rem; font-weight: 500; flex: 1; }

.snackbar-right { display: flex; align-items: center; gap: .75rem; flex-shrink: 0; }

.snackbar-undo {
  font-size: .85rem; font-weight: 800;
  color: #A5B4FC; /* indigo-300 */
  padding: .25rem .5rem;
  border-radius: var(--radius-sm);
  transition: background .15s, color .15s;
  white-space: nowrap;
}
.snackbar-undo:hover { background: rgba(165,180,252,.15); color: #C7D2FE; }

/* Progress bar drains over the snackbar's lifetime */
.snackbar-progress {
  position: absolute; bottom: 0; left: 0;
  height: 3px;
  width: 100%;
  background: #A5B4FC;
  border-radius: 0 0 var(--radius-lg) var(--radius-lg);
  transition: width linear;
}

/* Brand name size — shrink on very small screens */
@media (max-width: 480px) {
  .brand-name { font-size: 1rem; }
  .snackbar { min-width: unset; }
}

/* ─────────────────────────────────────────────────────────────────────────
   SUMMARY TAB
   ───────────────────────────────────────────────────────────────────────── */
.summary-panel { padding-top: 1.5rem; padding-bottom: 3rem; }
.summary-toolbar {
  display: flex; align-items: center; justify-content: space-between;
  margin-bottom: 1rem;
}

.table-scroll-wrap {
  overflow-x: auto;
  border: 1.5px solid var(--clr-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  margin-bottom: 2.5rem;
}

.summary-table, .payment-table {
  width: 100%;
  border-collapse: collapse;
  font-size: .85rem;
  background: var(--clr-surface);
  white-space: nowrap;
}
.summary-table th, .payment-table th {
  background: var(--clr-bg);
  font-weight: 700;
  font-size: .78rem;
  text-transform: uppercase;
  letter-spacing: .05em;
  color: var(--clr-text-muted);
  padding: .75rem 1rem;
  border-bottom: 1.5px solid var(--clr-border);
  text-align: left;
}
.summary-table td, .payment-table td {
  padding: .7rem 1rem;
  border-bottom: 1px solid var(--clr-border);
  vertical-align: middle;
}
.summary-table tr:last-child td, .payment-table tr:last-child td { border-bottom: none; }
.summary-table tr:hover td { background: var(--clr-bg); }

.total-row td { font-weight: 700; background: var(--clr-bg) !important; border-top: 2px solid var(--clr-border); }

.title-cell   { min-width: 140px; max-width: 220px; }
.num-cell     { text-align: right; font-variant-numeric: tabular-nums; }
.text-cell    { min-width: 100px; }
.date-cell    { min-width: 120px; }
.arrow-cell   { text-align: center; color: var(--clr-text-muted); }
.settled-cell { text-align: center; color: var(--clr-success); font-weight: 600; padding: 1.5rem; }

.amount-negative { color: var(--clr-danger); }
.amount-positive { color: var(--clr-success); }
.amount-bold     { font-weight: 700; }

/* ─────────────────────────────────────────────────────────────────────────
   RESPONSIVE — Tablet 768px+
   ───────────────────────────────────────────────────────────────────────── */
@media (min-width: 768px) {
  :root { --gap: 1.5rem; }
  .container { padding-inline: 1.75rem; }

  .groups-grid { grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); }

  .tab-btn { flex: none; padding: .8rem 2rem; }

  .form-row { grid-template-columns: 1fr 1fr; }
}

/* ─────────────────────────────────────────────────────────────────────────
   RESPONSIVE — Desktop 1024px+
   ───────────────────────────────────────────────────────────────────────── */
@media (min-width: 1024px) {
  :root { --gap: 1.75rem; }
  .container { padding-inline: 2.5rem; }

  .groups-grid { grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); }
  .home-main { padding-top: 2.5rem; }

  .modal-box { padding: 2.25rem; }

  .expense-list { gap: .85rem; }

  .balance-grid { grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); }
}

/* ─────────────────────────────────────────────────────────────────────────
   RESPONSIVE — Large Desktop 1280px+
   ───────────────────────────────────────────────────────────────────────── */
@media (min-width: 1280px) {
  .groups-grid { grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); }
}

/* ─────────────────────────────────────────────────────────────────────────
   RESPONSIVE — 2K 1536px+
   ───────────────────────────────────────────────────────────────────────── */
@media (min-width: 1536px) {
  :root { --container-max: 1600px; }
  html { font-size: 17px; }
  .groups-grid { grid-template-columns: repeat(auto-fill, minmax(340px, 1fr)); }
  .balance-grid { grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); }
}

/* ─────────────────────────────────────────────────────────────────────────
   RESPONSIVE — Mobile (max 640px) tweaks
   ───────────────────────────────────────────────────────────────────────── */
@media (max-width: 640px) {
  .form-row { grid-template-columns: 1fr; }
  .expense-row-main { flex-wrap: wrap; }
  .payment-amount { margin-left: 0; }
  .toast-container { left: 1rem; right: 1rem; bottom: 1rem; }
  .toast { max-width: 100%; }
  .modal-box { padding: 1.25rem; border-radius: var(--radius-lg); }
  .tab-btn { padding: .75rem .4rem; font-size: .8rem; }
}