:root {
    --primary: #2c3e50;
    --accent: #3498db;
    --success: #27ae60;
    --danger: #e74c3c;
    --light: #ecf0f1;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f4f7f6;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
}

.container { width: 100%; max-width: 400px; padding: 20px; }

.card {
    background: white;
    padding: 30px;
    border-radius: 15px;
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
    text-align: center;
}

.hidden { display: none; }

h1 span { color: var(--accent); }

input, select {
    width: 100%;
    padding: 12px;
    margin: 10px 0;
    border: 1px solid #ddd;
    border-radius: 8px;
    box-sizing: border-box;
}

button {
    width: 100%;
    padding: 12px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-weight: bold;
    transition: 0.3s;
    margin-top: 10px;
}

.primary-btn { background: var(--accent); color: white; }
.logout-btn { background: #eee; color: var(--danger); }

.balance-card {
    background: var(--primary);
    color: white;
    padding: 20px;
    border-radius: 12px;
    margin: 20px 0;
}

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

.stats-grid { margin: 20px 0; display: flex; justify-content: space-around; }
.stat-box { background: var(--light); padding: 15px; border-radius: 8px; font-weight: bold; }