:root {
    /* Light Theme */
    --bg-color: #f8fafc;
    --card-bg: rgba(255, 255, 255, 0.7);
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --accent-color: #3b82f6;
    --accent-hover: #2563eb;
    --border-color: rgba(255, 255, 255, 0.5);
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --danger: #ef4444;
    --success: #10b981;
}

[data-theme="dark"] {
    --bg-color: #0f172a;
    --card-bg: rgba(30, 41, 59, 0.7);
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --accent-color: #60a5fa;
    --accent-hover: #3b82f6;
    --border-color: rgba(255, 255, 255, 0.1);
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -1px rgba(0, 0, 0, 0.2);
}

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

body {
    font-family: system-ui, -apple-system, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    transition: background-color 0.3s, color 0.3s;
    -webkit-font-smoothing: antialiased;
}

/* Typography */
h1 { font-size: 1.25rem; font-weight: 700; color: var(--text-primary); }
h2 { font-size: 1.1rem; font-weight: 600; margin-bottom: 0.5rem; }
p, span { font-size: 0.9rem; color: var(--text-secondary); }

/* Layout */
.app-container {
    display: flex;
    flex-direction: column;
    height: 100vh;
    height: 100dvh;
}

/* Top Nav */
.top-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 1.5rem;
    background: var(--card-bg);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 10;
}

.brand {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--accent-color);
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.status-badge {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0.25rem;
    border-radius: 50%;
    width: 32px;
    height: 32px;
}

.status-badge.offline {
    color: var(--danger);
    background: rgba(239, 68, 68, 0.1);
}

.status-badge.online {
    color: var(--success);
    background: rgba(16, 185, 129, 0.1);
}

.icon-btn {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 50%;
    transition: all 0.2s;
    display: flex;
}

.icon-btn:hover {
    background: rgba(0, 0, 0, 0.05);
    color: var(--text-primary);
}

/* Main Content */
.content-area {
    flex: 1;
    overflow-y: auto;
    padding: 1.5rem;
    padding-bottom: 80px; /* Space for bottom nav */
}

/* Bottom Nav (Mobile) */
.bottom-nav {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: var(--card-bg);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: space-around;
    align-items: center;
    padding: 0.5rem 1rem;
    padding-bottom: calc(0.5rem + env(safe-area-inset-bottom));
    z-index: 100;
}

.nav-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.25rem;
    text-decoration: none;
    color: var(--text-secondary);
    min-width: 60px;
    transition: color 0.2s;
}

.nav-item span {
    font-size: 0.75rem;
    font-weight: 500;
}

.nav-item.active {
    color: var(--accent-color);
}

.nav-item.active span {
    color: var(--accent-color);
}

.fab {
    background: var(--accent-color);
    color: white;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 10px rgba(59, 130, 246, 0.4);
    transform: translateY(-20px);
    transition: transform 0.2s;
}

.fab:active {
    transform: translateY(-18px) scale(0.95);
}

/* Glass Panels / Cards */
.glass-panel {
    background: var(--card-bg);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 1.25rem;
    box-shadow: var(--shadow);
    margin-bottom: 1rem;
}

/* Grid Layouts */
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
.grid-4 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1rem; }

@media (min-width: 768px) {
    .grid-4 { grid-template-columns: repeat(4, 1fr); }
    .bottom-nav {
        /* On larger screens, could change this to sidebar, but keeping simple for PWA */
    }
}

/* Stat Cards */
.stat-card {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.stat-icon {
    width: 48px;
    height: 48px;
    border-radius: 12px;
    background: rgba(59, 130, 246, 0.1);
    color: var(--accent-color);
    display: flex;
    align-items: center;
    justify-content: center;
}

.stat-info h3 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
}

/* Tables */
.table-wrapper {
    overflow-x: auto;
}
table {
    width: 100%;
    border-collapse: collapse;
}
th, td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}
th {
    font-weight: 600;
    color: var(--text-secondary);
    white-space: nowrap;
}

/* Forms & Inputs */
.form-group {
    margin-bottom: 1rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-primary);
}

.form-control {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background: transparent;
    color: var(--text-primary);
    font-family: inherit;
    outline: none;
    transition: border-color 0.2s;
}

.form-control:focus {
    border-color: var(--accent-color);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    background: var(--accent-color);
    color: white;
    border: none;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.2s;
    font-family: inherit;
}

.btn:hover { background: var(--accent-hover); }
.btn-outline {
    background: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-primary);
}
.btn-outline:hover { background: rgba(0,0,0,0.05); }

/* Modals */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    padding: 1rem;
}

.modal-overlay.hidden { display: none; }

.modal-content {
    width: 100%;
    max-width: 500px;
    max-height: 90vh;
    display: flex;
    flex-direction: column;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.modal-body-content {
    overflow-y: auto;
}

/* Utilities */
.text-right { text-align: right; }
.badge {
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    font-size: 0.75rem;
    font-weight: 600;
}
.badge.in { background: rgba(16, 185, 129, 0.1); color: var(--success); }
.badge.out { background: rgba(239, 68, 68, 0.1); color: var(--danger); }