/* Modern & Clean CSS Variables */
:root {
    --primary-color: #4361ee;
    --secondary-color: #3f37c9;
    --accent-color: #4cc9f0;
    --success-color: #10b981;
    --danger-color: #ef476f;
    --bg-color: #f8f9fa;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --card-bg: #ffffff;
    --border-radius: 12px;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --font-family: 'Sarabun', 'Inter', sans-serif;
}

body {
    background-color: var(--bg-color);
    font-family: var(--font-family);
    color: var(--text-primary);
    -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    color: var(--text-primary);
}

/* Card Styling */
.card {
    background-color: var(--card-bg);
    border: none;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-md);
    transition: transform 0.2s ease-in-out;
}

.card-header {
    background-color: transparent;
    border-bottom: 1px solid #f3f4f6;
    font-weight: 600;
    padding: 1.25rem;
}

/* Buttons */
.btn-primary {
    background-color: var(--primary-color);
    border-color: var(--primary-color);
    padding: 0.6rem 1.2rem;
    border-radius: 8px;
    font-weight: 500;
}

.btn-primary:hover {
    background-color: var(--secondary-color);
    border-color: var(--secondary-color);
}

/* Forms */
.form-control {
    border-radius: 8px;
    padding: 0.75rem 1rem;
    border: 1px solid #d1d5db;
}

.form-control:focus {
    box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.15);
    border-color: var(--primary-color);
}

/* Mobile Responsiveness */
@media (max-width: 768px) {
    .container {
        padding-left: 1rem;
        padding-right: 1rem;
    }
}

/* Navbar */
.navbar {
    background-color: var(--card-bg);
    box-shadow: var(--shadow-sm);
    padding: 0.8rem 1rem;
}

.navbar-brand {
    font-weight: 700;
    color: var(--primary-color) !important;
}

/* Utilities */
.text-muted-small {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.status-badge {
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 500;
}

.status-success { background-color: #d1fae5; color: #065f46; }
.status-danger { background-color: #fee2e2; color: #991b1b; }
.status-warning { background-color: #fef3c7; color: #92400e; }