/* Modern Glassy UI - Enterprise SaaS Variables */
:root {
    /* System Globals */
    --primary-color: #1e88e5;
    --secondary-color: #1565c0;
    --accent-color: #ffb300;
    
    /* Light Theme (Default) */
    --bg-primary: #f8fafc;
    --bg-secondary: transparent;
    --surface: rgba(255, 255, 255, 0.7);
    --surface-hover: rgba(255, 255, 255, 0.9);
    --surface-border: rgba(255, 255, 255, 0.5);
    
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: rgba(0, 0, 0, 0.05);
    
    --glass-blur: blur(20px);
    --shadow-sm: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
    --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.05), 0 4px 6px -2px rgba(0, 0, 0, 0.025);
    --shadow-hover: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    
    --transition-smooth: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --surface: rgba(30, 41, 59, 0.75);
    --surface-hover: rgba(51, 65, 85, 0.9);
    --surface-border: rgba(255, 255, 255, 0.08);
    
    --text-primary: #f8fafc;
    --text-secondary: #cbd5e1;
    --border-color: rgba(255, 255, 255, 0.05);
}

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

body {
    font-family: 'Inter', 'Segoe UI', system-ui, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    transition: var(--transition-smooth);
    min-height: 100vh;
}

/* Glassmorphism Navigation */
.navbar {
    background: var(--surface);
    backdrop-filter: var(--glass-blur);
    border-bottom: 1px solid var(--surface-border);
    padding: 1rem 2rem;
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 1000;
    transition: var(--transition-smooth);
}

.navbar-brand {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    letter-spacing: -0.025em;
}

/* Glassy Cards */
.card {
    background: var(--surface);
    backdrop-filter: var(--glass-blur);
    border-radius: 16px;
    border: 1px solid var(--surface-border);
    box-shadow: var(--shadow-md);
    margin-bottom: 1.5rem;
    overflow: hidden;
    transition: var(--transition-smooth);
}

.card:hover {
    box-shadow: var(--shadow-hover);
}

.card-header {
    background: rgba(0, 0, 0, 0.02);
    color: var(--text-primary);
    padding: 1.25rem 1.5rem;
    border-bottom: 1px solid var(--border-color);
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

/* Interactive Buttons */
.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition-smooth);
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    min-height: 48px; /* Touch friendly */
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.btn-primary:hover {
    transform: translateY(-2px) scale(1.02);
    box-shadow: 0 10px 15px rgba(0, 0, 0, 0.2);
    filter: brightness(1.1);
}

.btn-danger {
    background: linear-gradient(135deg, #ef4444, #dc2626);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition-smooth);
    min-height: 48px;
}

.btn-danger:hover {
    transform: translateY(-2px) scale(1.02);
    box-shadow: 0 10px 15px rgba(220, 38, 38, 0.3);
}

/* Modern Tables */
.table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
}

.table th {
    background: rgba(0, 0, 0, 0.02);
    color: var(--text-secondary);
    font-weight: 600;
    padding: 1rem 1.5rem;
    text-align: left;
    text-transform: uppercase;
    font-size: 0.75rem;
    letter-spacing: 0.05em;
    border-bottom: 2px solid var(--border-color);
}

[data-theme="dark"] .table th { background: rgba(255, 255, 255, 0.02); }

.table td {
    padding: 1rem 1.5rem;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-primary);
    transition: var(--transition-smooth);
}

.table tbody tr:hover td {
    background: rgba(0, 0, 0, 0.01);
}
[data-theme="dark"] .table tbody tr:hover td { background: rgba(255, 255, 255, 0.02); }

/* Forms & Inputs */
.form-control {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background: var(--surface);
    color: var(--text-primary);
    transition: var(--transition-smooth);
    min-height: 48px; /* Touch friendly */
}

.form-control:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(30, 136, 229, 0.15);
    background: var(--surface-hover);
}

/* Dashboard Stats */
.dashboard-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: var(--surface);
    backdrop-filter: var(--glass-blur);
    padding: 1.5rem;
    border-radius: 12px;
    border: 1px solid var(--surface-border);
    box-shadow: var(--shadow-md);
    transition: var(--transition-smooth);
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.stat-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

.stat-number {
    font-size: 2.25rem;
    font-weight: 800;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.stat-label {
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.fade-in {
    animation: fadeIn 0.4s cubic-bezier(0.4, 0, 0.2, 1) forwards;
}

/* Theme Toggle Button */
.theme-toggle {
    background: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    width: 48px;
    height: 48px;
    border-radius: 50%;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: var(--transition-smooth);
}

.theme-toggle:hover {
    background: var(--surface-hover);
    transform: rotate(15deg);
}

/* Grid POS Overrides */
.pos-layout {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 20px;
    height: calc(100vh - 80px); /* 100vw/100vh exact fit minus navbar */
    overflow: hidden;
}

/* Advanced responsive constraints */
@media (max-width: 1024px) {
    .pos-layout {
        grid-template-columns: 1.5fr 1fr;
    }
}
@media (max-width: 768px) {
    .pos-layout {
        grid-template-columns: 1fr;
        height: auto;
        overflow-y: auto;
    }
    .header-actions {
        display: none; /* Collapsible handled in JS */
    }
}