body {
  margin: 0;
  font-family: 'Poppins', sans-serif;
  background: linear-gradient(135deg, #0f172a, #1e293b);
  color: white;
}

/* container */
.container {
  max-width: 420px;
  margin: auto;
  padding: 15px;
}

/* header */
.header {
  text-align: center;
  padding: 15px;
  font-size: 20px;
  font-weight: bold;
}

/* card */
.card {
  background: #1e293b;
  border-radius: 15px;
  padding: 15px;
  margin: 10px 0;
  box-shadow: 0 5px 15px rgba(0,0,0,0.3);
}

/* balance */
.balance {
  background: linear-gradient(135deg, #22c55e, #4ade80);
  color: black;
  text-align: center;
  font-size: 22px;
  font-weight: bold;
}

/* buttons */
.btn {
  display: block;
  text-align: center;
  padding: 12px;
  background: #3b82f6;
  color: white;
  border-radius: 10px;
  text-decoration: none;
  margin-top: 10px;
  transition: 0.2s;
}

.btn:hover {
  background: #2563eb;
}

/* grid */
.grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

/* nav bar */
.nav {
  position: fixed;
  bottom: 0;
  width: 100%;
  max-width: 420px;
  background: #020617;
  display: flex;
  justify-content: space-around;
  padding: 10px 0;
}

.nav a {
  color: white;
  text-decoration: none;
  font-size: 14px;
}

/* inputs */
input, select {
  width: 100%;
  padding: 10px;
  margin: 8px 0;
  border-radius: 8px;
  border: none;
}

/* form */
form {
  margin-top: 10px;
}
.card {
  transition: 0.3s;
}

.card:hover {
  transform: translateY(-5px) scale(1.02);
}

.btn {
  transition: 0.3s;
}

.btn:active {
  transform: scale(0.95);
}