* { margin: 0; padding: 0; box-sizing: border-box; }

:root {
  --bg: #f1f5f9;
  --card: #ffffff;
  --primary: #4f46e5;
  --primary-light: #e0e7ff;
  --text: #0f172a;
  --muted: #64748b;
  --border: #e2e8f0;
  --sale: #22c55e;
  --purchase: #ef4444;
  --credit: #3b82f6;
  --debit: #f97316;
  --radius: 12px;
}

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

/* ---- LOGIN ---- */
.login-screen {
  display: flex;
  position: fixed;
  inset: 0;
  background: var(--bg);
  z-index: 100;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 20px;
}
.login-screen.hidden { display: none; }

.login-title {
  font-size: 24px;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 8px;
}
.login-subtitle {
  color: var(--muted);
  margin-bottom: 24px;
}

#user-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
  gap: 12px;
  width: 100%;
  max-width: 400px;
  margin-bottom: 24px;
}

.user-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  padding: 16px 8px;
  border: 2px solid var(--border);
  border-radius: var(--radius);
  background: var(--card);
  cursor: pointer;
  transition: all 0.15s;
}
.user-card:hover, .user-card.selected {
  border-color: var(--primary);
  background: var(--primary-light);
}
.user-avatar {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--primary);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  font-weight: 700;
}
.user-name {
  font-size: 13px;
  font-weight: 500;
}

#pin-section {
  display: none;
  width: 100%;
  max-width: 300px;
  text-align: center;
}
#pin-section.active { display: block; }

#pin-display {
  font-size: 32px;
  letter-spacing: 12px;
  margin-bottom: 16px;
  color: var(--text);
  min-height: 40px;
}
#pin-display.error { color: var(--purchase); }

.pin-pad {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
}
.pin-key {
  padding: 16px;
  font-size: 20px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--card);
  cursor: pointer;
  transition: background 0.1s;
}
.pin-key:active { background: var(--primary-light); }
.pin-key.special { font-size: 14px; background: var(--bg); }

.add-user-link {
  margin-top: 16px;
  color: var(--primary);
  cursor: pointer;
  font-size: 14px;
  text-decoration: underline;
}

/* ---- APP SHELL ---- */
#app { display: none; }
#app.active { display: block; }

.app-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--primary);
  color: white;
  padding: 12px 16px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.app-header h1 {
  font-size: 16px;
  font-weight: 600;
}
.header-balance {
  font-size: 18px;
  font-weight: 700;
}
.header-user {
  font-size: 12px;
  opacity: 0.8;
}
#logout-btn {
  background: rgba(255,255,255,0.15);
  border: none;
  color: white;
  padding: 6px 12px;
  border-radius: 6px;
  cursor: pointer;
  font-size: 12px;
}

.view {
  display: none;
  padding: 16px;
  padding-bottom: 80px;
}
.view.active { display: block; }

/* ---- BOTTOM NAV ---- */
.bottom-nav {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  background: var(--card);
  border-top: 1px solid var(--border);
  display: flex;
  z-index: 50;
  padding-bottom: env(safe-area-inset-bottom);
}
.nav-btn {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  padding: 8px 4px;
  border: none;
  background: none;
  color: var(--muted);
  font-size: 10px;
  cursor: pointer;
  transition: color 0.15s;
}
.nav-btn.active { color: var(--primary); }
.nav-btn .nav-icon {
  font-size: 20px;
  line-height: 1;
}

/* ---- CARDS ---- */
.card {
  background: var(--card);
  border-radius: var(--radius);
  padding: 16px;
  margin-bottom: 12px;
  box-shadow: 0 1px 3px rgba(0,0,0,0.06);
}
.card-title {
  font-size: 13px;
  color: var(--muted);
  margin-bottom: 8px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

/* ---- HOME ---- */
.summary-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-bottom: 16px;
}
.summary-item {
  background: var(--card);
  border-radius: var(--radius);
  padding: 14px;
  text-align: center;
  box-shadow: 0 1px 3px rgba(0,0,0,0.06);
}
.summary-label {
  font-size: 11px;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}
.summary-value {
  font-size: 20px;
  font-weight: 700;
  margin-top: 4px;
}
.summary-value.sale { color: var(--sale); }
.summary-value.purchase { color: var(--purchase); }
.summary-value.credit { color: var(--credit); }
.summary-value.debit { color: var(--debit); }

.section-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 8px;
}
.section-title {
  font-size: 15px;
  font-weight: 600;
}

/* ---- TRANSACTION CARDS ---- */
.txn-card {
  background: var(--card);
  border-radius: var(--radius);
  padding: 12px 14px;
  margin-bottom: 8px;
  box-shadow: 0 1px 2px rgba(0,0,0,0.04);
}
.txn-main {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.txn-type {
  font-size: 13px;
  font-weight: 600;
  text-transform: uppercase;
}
.txn-amount {
  font-size: 18px;
  font-weight: 700;
}
.txn-detail {
  font-size: 13px;
  color: var(--muted);
  margin-top: 4px;
}
.txn-meta {
  font-size: 11px;
  color: var(--muted);
  margin-top: 2px;
}
.txn-actions {
  display: flex;
  gap: 8px;
  margin-top: 8px;
  padding-top: 8px;
  border-top: 1px solid var(--border);
}
.txn-edit-btn, .txn-delete-btn {
  padding: 4px 12px;
  border: none;
  border-radius: 6px;
  font-size: 12px;
  font-weight: 500;
  cursor: pointer;
}
.txn-edit-btn { background: var(--primary-light); color: var(--primary); }
.txn-delete-btn { background: #fee2e2; color: var(--purchase); }

/* ---- NEW TRANSACTION ---- */
.type-selector {
  display: flex;
  gap: 8px;
  margin-bottom: 16px;
  flex-wrap: wrap;
}
.type-btn {
  flex: 1;
  min-width: 70px;
  padding: 10px 8px;
  border: 2px solid var(--border);
  border-radius: 8px;
  background: var(--card);
  cursor: pointer;
  font-size: 13px;
  font-weight: 500;
  text-align: center;
  transition: all 0.15s;
}
.type-btn.active {
  border-color: var(--primary);
  background: var(--primary-light);
  color: var(--primary);
}
.type-btn[data-type="sale"].active { border-color: var(--sale); color: var(--sale); }
.type-btn[data-type="purchase"].active { border-color: var(--purchase); color: var(--purchase); }
.type-btn[data-type="credit"].active { border-color: var(--credit); color: var(--credit); }
.type-btn[data-type="debit"].active { border-color: var(--debit); color: var(--debit); }

.form-group {
  margin-bottom: 14px;
}
.form-label {
  display: block;
  font-size: 13px;
  font-weight: 500;
  color: var(--muted);
  margin-bottom: 6px;
}
.form-input {
  width: 100%;
  padding: 12px;
  border: 1.5px solid var(--border);
  border-radius: 8px;
  font-size: 16px;
  background: var(--card);
  transition: border-color 0.15s;
}
.form-input:focus {
  outline: none;
  border-color: var(--primary);
}
.form-input.amount {
  font-size: 24px;
  font-weight: 700;
  text-align: center;
}

#items-section { display: none; }
#items-section.active { display: block; }

.item-row {
  display: flex;
  gap: 8px;
  align-items: center;
  margin-bottom: 8px;
}
.item-row select, .item-row input {
  padding: 10px;
  border: 1.5px solid var(--border);
  border-radius: 8px;
  font-size: 14px;
  background: var(--card);
}
.item-row select { flex: 1; min-width: 0; }
.item-row input { flex: 1; min-width: 0; }
.item-remove {
  width: 32px;
  height: 32px;
  border: none;
  border-radius: 50%;
  background: #fee2e2;
  color: var(--purchase);
  font-size: 18px;
  cursor: pointer;
  flex-shrink: 0;
}
.add-item-btn {
  width: 100%;
  padding: 10px;
  border: 2px dashed var(--border);
  border-radius: 8px;
  background: none;
  color: var(--primary);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
}
.add-item-btn:hover { border-color: var(--primary); background: var(--primary-light); }

#item-total {
  text-align: right;
  font-size: 13px;
  color: var(--muted);
  margin-top: 4px;
}

.btn-primary {
  width: 100%;
  padding: 14px;
  border: none;
  border-radius: var(--radius);
  background: var(--primary);
  color: white;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: opacity 0.15s;
}
.btn-primary:hover { opacity: 0.9; }
.btn-primary:active { transform: scale(0.98); }

/* ---- HISTORY ---- */
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 16px;
}
.filter-bar select, .filter-bar input {
  padding: 8px 10px;
  border: 1.5px solid var(--border);
  border-radius: 8px;
  font-size: 13px;
  background: var(--card);
}
.filter-bar select { flex: 1; min-width: 0; }
.filter-bar input { flex: 1; min-width: 0; }
.filter-apply {
  padding: 8px 16px;
  border: none;
  border-radius: 8px;
  background: var(--primary);
  color: white;
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
}
.history-total {
  text-align: right;
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 12px;
}

.empty {
  text-align: center;
  color: var(--muted);
  padding: 40px 0;
}

/* ---- SETTINGS ---- */
.setting-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 0;
  border-bottom: 1px solid var(--border);
}
.setting-id {
  font-size: 11px;
  color: var(--muted);
  font-family: monospace;
}

.balance-input-row {
  display: flex;
  gap: 8px;
  align-items: center;
}
.balance-input-row input {
  flex: 1;
  padding: 10px;
  border: 1.5px solid var(--border);
  border-radius: 8px;
  font-size: 16px;
}
.balance-input-row button {
  padding: 10px 16px;
  border: none;
  border-radius: 8px;
  background: var(--primary);
  color: white;
  font-weight: 500;
  cursor: pointer;
}

.btn-add {
  display: inline-block;
  padding: 8px 16px;
  border: none;
  border-radius: 8px;
  background: var(--primary-light);
  color: var(--primary);
  font-weight: 500;
  cursor: pointer;
  margin-top: 8px;
}

/* ---- MODAL ---- */
.modal-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.4);
  z-index: 200;
  align-items: center;
  justify-content: center;
  padding: 20px;
}
.modal-overlay.active { display: flex; }

.modal {
  background: var(--card);
  border-radius: var(--radius);
  padding: 24px;
  width: 100%;
  max-width: 360px;
}
.modal h3 {
  margin-bottom: 16px;
  font-size: 18px;
}
.modal-actions {
  display: flex;
  gap: 8px;
  margin-top: 16px;
}
.modal-actions button {
  flex: 1;
  padding: 10px;
  border: none;
  border-radius: 8px;
  font-weight: 500;
  cursor: pointer;
}
.modal-actions .btn-cancel { background: var(--bg); color: var(--text); }
.modal-actions .btn-save { background: var(--primary); color: white; }

/* ---- RESPONSIVE ---- */
@media (min-width: 600px) {
  .view { max-width: 480px; margin: 0 auto; }
  #user-grid { grid-template-columns: repeat(4, 1fr); }
}