:root {
    /* Brand Colors */
    --color-primary: #27ae60;    /* Green */
    --color-primary-dark: #219150;
    --color-danger: #e74c3c;     /* Red */
    --color-warning: #f39c12;    /* Orange/Yellow */
    --color-dark: #2c3e50;
    --color-light: #ecf0f1;
    --color-white: #ffffff;
    --color-gray: #95a5a6;

    /* Spacing & Layout */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --border-radius: 8px;
    --shadow: 0 2px 5px rgba(0,0,0,0.1);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Mukta', sans-serif; /* Marathi Font */
}

body {
    background-color: #f5f6fa;
    color: var(--color-dark);
    font-size: 16px;
    line-height: 1.5;
}

#app {
    max-width: 480px; /* Mobile View Width */
    margin: 0 auto;
    background-color: var(--color-white);
    min-height: 100vh;
    box-shadow: 0 0 20px rgba(0,0,0,0.05);
    position: relative;
    padding-bottom: 60px; /* Space for bottom nav */
}

/* Utilities */
.hidden { display: none !important; }
.text-center { text-align: center; }
.text-primary { color: var(--color-primary); }
.text-danger { color: var(--color-danger); }
.mt-2 { margin-top: var(--spacing-sm); }
.mb-2 { margin-bottom: var(--spacing-sm); }
.p-2 { padding: var(--spacing-md); }

/* Buttons */
.btn {
    display: block;
    width: 100%;
    padding: 12px;
    border: none;
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    text-align: center;
    transition: background 0.2s;
    margin-bottom: var(--spacing-md);
}

.btn-primary {
    background-color: var(--color-primary);
    color: white;
}
.btn-primary:active { background-color: var(--color-primary-dark); }

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

.btn-outline {
    background-color: transparent;
    border: 2px solid var(--color-primary);
    color: var(--color-primary);
}

/* Cards */
.card {
    background: white;
    padding: var(--spacing-md);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    margin-bottom: var(--spacing-md);
    border: 1px solid #eee;
}

/* Inputs */
.form-group {
    margin-bottom: var(--spacing-md);
}
.form-label {
    display: block;
    margin-bottom: var(--spacing-xs);
    font-weight: 500;
}
.form-input {
    width: 100%;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: var(--border-radius);
    font-size: 1rem;
}

/* Header */
header {
    background-color: var(--color-primary);
    color: white;
    padding: var(--spacing-md);
    text-align: center;
    position: sticky;
    top: 0;
    z-index: 100;
}
header h1 {
    font-size: 1.2rem;
    margin: 0;
}

/* Print Styles for Billing */
@media print {
    body { background-color: white; }
    #app { box-shadow: none; max-width: 100%; }
    .no-print { display: none; }
}