:root {
    --bg-color: #f5f7fa;
    --card-color: #ffffff;
    --primary: #4f46e5;
    --text: #111827;
    --muted: #6b7280;
    --positive: #16a34a;
    --negative: #dc2626;
    --radius: 12px;
}

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

body {
    font-family: 'Segoe UI', sans-serif;
    background-color: var(--bg-color);
    color: var(--text);
    padding: 16px;
}

.wallet-app {
    max-width: 420px;
    margin: 0 auto;
}

.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
}

.user-avatar {
    background-color: var(--primary);
    color: white;
    border-radius: 50%;
    width: 36px;
    height: 36px;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 18px;
}

.balance-section {
    background: var(--card-color);
    padding: 24px;
    border-radius: var(--radius);
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.05);
    text-align: center;
    margin-bottom: 24px;
}

.balance-section .label {
    color: var(--muted);
    margin-bottom: 8px;
}

.balance-section h2 {
    font-size: 32px;
    margin-bottom: 16px;
}

.actions {
    display: flex;
    justify-content: center;
    gap: 12px;
}

.btn {
    padding: 10px 20px;
    border: none;
    border-radius: var(--radius);
    font-weight: bold;
    cursor: pointer;
    font-size: 14px;
}

.btn.send {
    background-color: var(--negative);
    color: white;
}

.btn.receive {
    background-color: var(--positive);
    color: white;
}

.transactions-section {
    margin-bottom: 24px;
}

.transactions-section h3 {
    margin-bottom: 12px;
}

.transaction-list {
    background: var(--card-color);
    border-radius: var(--radius);
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.05);
    padding: 16px;
}

.transaction {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 0;
    border-bottom: 1px solid #e5e7eb;
}

.transaction:last-child {
    border-bottom: none;
}

.transaction small {
    color: var(--muted);
    font-size: 12px;
}

.amount {
    font-weight: bold;
}

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

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

.bottom-nav {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  height: 64px;
  background: var(--card-color);
  display: flex;
  justify-content: space-around;
  align-items: center;
  border-top: 1px solid #e5e7eb;
  box-shadow: 0 -1px 4px rgba(0,0,0,0.05);
  z-index: 10;
}

.nav-item {
  flex: 1;
  text-align: center;
  font-size: 12px;
  color: var(--muted);
  text-decoration: none;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.nav-item span {
  font-size: 20px;
  margin-bottom: 2px;
}

.nav-item.active {
  color: var(--primary);
  font-weight: bold;
}