:root {
  --primary: #007aff;
  --bg: #f2f2f7;
  --card-bg: #ffffff;
  --text-main: #1c1c1e;
  --text-muted: #8e8e93;
  --green: #34c759;
  --red: #ff3b30;
  --border: #e5e5ea;
  --font-family: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #000000;
    --card-bg: #1c1c1e;
    --text-main: #ffffff;
    --text-muted: #8e8e93;
    --border: #2c2c2e;
  }
}

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

body {
  font-family: var(--font-family);
  background-color: var(--bg);
  color: var(--text-main);
  line-height: 1.5;
  min-height: 100vh;
  display: flex;
  justify-content: center;
}

.app-container {
  width: 100%;
  max-width: 480px;
  padding: 24px 16px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.hero-header {
  text-align: center;
  padding: 12px 0;
}

.logo-badge {
  font-size: 40px;
  margin-bottom: 8px;
}

.hero-header h1 {
  font-size: 26px;
  font-weight: 800;
  letter-spacing: -0.5px;
}

.subtitle {
  color: var(--text-muted);
  font-size: 14px;
}

.lookup-card, .trip-dashboard {
  background: var(--card-bg);
  border-radius: 16px;
  padding: 20px;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.05);
}

.lookup-card label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  margin-bottom: 8px;
}

.input-row {
  display: flex;
  gap: 8px;
}

.input-row input {
  flex: 1;
  font-size: 18px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 2px;
  padding: 12px 16px;
  border: 1.5px solid var(--border);
  border-radius: 12px;
  background: transparent;
  color: var(--text-main);
}

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

.primary-btn {
  background: var(--primary);
  color: white;
  border: none;
  border-radius: 12px;
  padding: 0 20px;
  font-weight: 700;
  cursor: pointer;
  font-size: 15px;
  transition: opacity 0.2s;
}

.primary-btn:hover {
  opacity: 0.9;
}

.hint-text {
  font-size: 12px;
  color: var(--text-muted);
  margin-top: 10px;
}

.trip-hero {
  display: flex;
  align-items: center;
  gap: 16px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border);
}

.trip-emoji {
  font-size: 38px;
}

.trip-hero h2 {
  font-size: 20px;
  font-weight: 800;
}

.currency-tag {
  display: inline-block;
  background: var(--border);
  font-size: 11px;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: 6px;
  margin-top: 4px;
}

.tab-controls {
  display: flex;
  background: var(--bg);
  border-radius: 10px;
  padding: 4px;
  margin: 16px 0;
}

.tab-btn {
  flex: 1;
  border: none;
  background: transparent;
  padding: 8px;
  border-radius: 8px;
  font-weight: 600;
  font-size: 14px;
  cursor: pointer;
  color: var(--text-muted);
}

.tab-btn.active {
  background: var(--card-bg);
  color: var(--text-main);
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.08);
}

.tab-content {
  display: none;
}

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

.section-title {
  font-size: 13px;
  font-weight: 700;
  color: var(--text-muted);
  text-transform: uppercase;
  margin-bottom: 12px;
}

.balance-item, .expense-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 0;
  border-bottom: 1px solid var(--border);
}

.balance-item:last-child, .expense-item:last-child {
  border-bottom: none;
}

.balance-name, .expense-title {
  font-weight: 600;
  font-size: 15px;
}

.balance-val {
  font-weight: 700;
  font-size: 15px;
}

.val-positive {
  color: var(--green);
}

.val-negative {
  color: var(--red);
}

.val-zero {
  color: var(--text-muted);
}

.expense-subtitle {
  font-size: 12px;
  color: var(--text-muted);
  margin-top: 2px;
}

.expense-amount {
  font-weight: 700;
  font-size: 15px;
}

.alert {
  padding: 12px 16px;
  border-radius: 12px;
  font-size: 14px;
  font-weight: 600;
}

.alert-error {
  background: rgba(255, 59, 48, 0.12);
  color: var(--red);
}

.loading-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  padding: 24px;
  color: var(--text-muted);
}

.spinner {
  width: 28px;
  height: 28px;
  border: 3px solid var(--border);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.hidden {
  display: none !important;
}

/* Auth Header */
.apple-auth-btn, .google-auth-btn, .qr-auth-btn {
  display: flex;
  align-items: center;
  gap: 5px;
  background: var(--card-bg);
  border: 1px solid var(--border);
  color: var(--text-main);
  padding: 5px 10px;
  border-radius: 18px;
  font-size: 11px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s ease;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
}

.apple-auth-btn {
  background: #000;
  color: #fff;
  border-color: #000;
}

.apple-auth-btn:hover {
  background: #222;
}

.qr-auth-btn {
  background: #EEF2FF;
  color: #4F46E5;
  border-color: #C7D2FE;
}

.qr-auth-btn:hover {
  background: #E0E7FF;
}

.google-auth-btn:hover {
  background: var(--bg);
}

.user-profile-badge {
  display: flex;
  align-items: center;
  gap: 8px;
  background: var(--card-bg);
  border: 1px solid var(--border);
  padding: 4px 10px;
  border-radius: 20px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
}

.user-avatar {
  width: 22px;
  height: 22px;
  border-radius: 50%;
  object-fit: cover;
}

.user-name {
  font-size: 12px;
  font-weight: 600;
  color: var(--text-main);
  max-width: 100px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.sign-out-btn {
  background: transparent;
  border: none;
  color: var(--red);
  font-size: 11px;
  font-weight: 700;
  cursor: pointer;
  padding: 2px 4px;
}

.action-btn-small {
  background: var(--primary);
  color: white;
  border: none;
  padding: 6px 12px;
  border-radius: 8px;
  font-size: 12px;
  font-weight: 700;
  cursor: pointer;
  transition: opacity 0.15s ease;
}

.action-btn-small:hover {
  opacity: 0.9;
}

/* Modal */
.modal-backdrop {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(4px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  padding: 16px;
}

.modal-card {
  background: var(--card-bg);
  width: 100%;
  max-width: 440px;
  border-radius: 20px;
  padding: 24px;
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.18);
  animation: modalPop 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes modalPop {
  from { transform: scale(0.95); opacity: 0; }
  to { transform: scale(1); opacity: 1; }
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
}

.modal-header h3 {
  font-size: 18px;
  font-weight: 800;
  letter-spacing: -0.3px;
}

.close-modal-btn {
  background: transparent;
  border: none;
  font-size: 18px;
  color: var(--text-muted);
  cursor: pointer;
  padding: 4px;
}

.form-group {
  margin-bottom: 14px;
}

.form-group label {
  display: block;
  font-size: 12px;
  font-weight: 700;
  color: var(--text-muted);
  text-transform: uppercase;
  margin-bottom: 6px;
}

.form-group input, .form-group select {
  width: 100%;
  padding: 10px 14px;
  border: 1.5px solid var(--border);
  border-radius: 10px;
  font-size: 14px;
  font-weight: 600;
  background: var(--card-bg);
  color: var(--text-main);
  box-sizing: border-box;
}

.form-row {
  display: flex;
  gap: 10px;
}

.flex-1 {
  flex: 1;
}

.checkbox-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
  max-height: 120px;
  overflow-y: auto;
  padding: 8px 12px;
  background: var(--bg);
  border-radius: 10px;
}

.checkbox-label {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
}

.checkbox-label input[type="checkbox"] {
  width: 16px;
  height: 16px;
  accent-color: var(--primary);
  cursor: pointer;
}

.modal-actions {
  display: flex;
  gap: 10px;
  margin-top: 20px;
}

.btn-secondary {
  flex: 1;
  background: var(--bg);
  color: var(--text-main);
  border: 1px solid var(--border);
  padding: 12px;
  border-radius: 12px;
  font-size: 14px;
  font-weight: 700;
  cursor: pointer;
}

.modal-actions .primary-btn {
  flex: 1.5;
}

footer {
  text-align: center;
  font-size: 11px;
  color: var(--text-muted);
  margin-top: auto;
  padding-top: 24px;
}