:root {
    --primary: #4f46e5;
    --primary-hover: #4338ca;
    --primary-glow: rgba(79, 70, 229, 0.12);
    --bg-body: #f8fafc;
    --bg-card: #ffffff;
    --text-heading: #0f172a;
    --text-body: #334155;
    --text-muted: #64748b;
    --border-subtle: #e2e8f0;
    --border-hover: #cbd5e1;

    --success: #10b981;
    --success-bg: #ecfdf5;
    --success-border: #a7f3d0;
    --success-dark: #065f46;

    --warning: #f59e0b;
    --warning-bg: #fffbeb;
    --warning-border: #fde68a;
    --warning-dark: #92400e;

    --danger: #ef4444;
    --danger-bg: #fef2f2;
    --danger-border: #fecaca;
    --danger-dark: #991b1b;

    --info: #06b6d4;
    --info-bg: #ecfeff;
    --info-border: #cffafe;
    --info-dark: #155e75;

    --sidebar-width: 260px;
    --navbar-height: 70px;
    --radius-lg: 16px;
    --radius-md: 12px;
    --radius-sm: 8px;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.05), 0 4px 6px -4px rgba(0, 0, 0, 0.05);
}

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-body);
    color: var(--text-body);
    overflow-x: hidden;
    font-size: 0.92rem;
}

/* --- LOGIN PAGE --- */
#loginWrapper {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #e0e7ff 0%, #f1f5f9 100%);
    position: relative;
}

.login-card {
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    width: 100%;
    max-width: 440px;
    padding: 2.5rem;
    transition: transform 0.2s;
}

.login-brand {
    font-weight: 800;
    font-size: 1.8rem;
    letter-spacing: -0.04em;
    color: var(--primary);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
}

/* --- MAIN LAYOUT --- */
#appWrapper {
    display: none;
    min-height: 100vh;
}

/* Sidebar */
.sidebar {
    width: var(--sidebar-width);
    background: #ffffff;
    border-right: 1px solid var(--border-subtle);
    position: fixed;
    top: 0;
    bottom: 0;
    left: 0;
    z-index: 100;
    display: flex;
    flex-direction: column;
}

.sidebar-brand {
    height: var(--navbar-height);
    display: flex;
    align-items: center;
    padding: 0 1.5rem;
    border-bottom: 1px solid var(--border-subtle);
    font-weight: 800;
    font-size: 1.3rem;
    letter-spacing: -0.03em;
    color: var(--primary);
    gap: 0.5rem;
}

.sidebar-menu {
    padding: 1.5rem 0.75rem;
    flex: 1;
    overflow-y: auto;
}

.menu-label {
    font-size: 0.72rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
    padding: 0.75rem 0.75rem 0.35rem 0.75rem;
}

.menu-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.65rem 0.75rem;
    color: var(--text-body);
    text-decoration: none;
    border-radius: var(--radius-sm);
    font-weight: 500;
    transition: all 0.15s ease;
    margin-bottom: 0.2rem;
}

.menu-item:hover {
    background-color: var(--bg-body);
    color: var(--text-heading);
}

.menu-item.active {
    background-color: var(--primary-glow);
    color: var(--primary);
    font-weight: 600;
}

.sidebar-footer {
    padding: 1rem 1.25rem;
    border-top: 1px solid var(--border-subtle);
    background-color: var(--bg-body);
}

/* Top Navbar */
.navbar-custom {
    height: var(--navbar-height);
    background: #ffffff;
    border-bottom: 1px solid var(--border-subtle);
    position: fixed;
    top: 0;
    right: 0;
    left: var(--sidebar-width);
    z-index: 90;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 2rem;
}

/* Main Content Container */
.main-content {
    margin-left: var(--sidebar-width);
    margin-top: var(--navbar-height);
    padding: 2rem;
    min-height: calc(100vh - var(--navbar-height));
}

/* --- CARDS & STATS --- */
.stat-card {
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-md);
    padding: 1.5rem;
    box-shadow: var(--shadow-sm);
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: relative;
    overflow: hidden;
}

.stat-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: var(--stat-color, var(--primary));
}

.stat-icon {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-sm);
    background: var(--stat-bg, var(--primary-glow));
    color: var(--stat-color, var(--primary));
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.4rem;
}

/* --- TABLES & CONTENT --- */
.card-custom {
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    margin-bottom: 1.5rem;
}

.card-header-custom {
    padding: 1.25rem 1.5rem;
    border-bottom: 1px solid var(--border-subtle);
    display: flex;
    align-items: center;
    justify-content: space-between;
    background-color: transparent;
}

.table-custom th {
    font-weight: 700;
    text-transform: uppercase;
    font-size: 0.74rem;
    letter-spacing: 0.05em;
    color: var(--text-muted);
    background-color: var(--bg-body);
    border-bottom: 1px solid var(--border-subtle);
    padding: 0.85rem 1rem;
}

.table-custom td {
    padding: 1rem;
    vertical-align: middle;
    border-bottom: 1px solid var(--border-subtle);
}

/* --- BADGES --- */
.badge-status {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    padding: 0.3rem 0.65rem;
    border-radius: 20px;
    font-size: 0.72rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.02em;
}

.badge-status.active { background: var(--success-bg); border: 1px solid var(--success-border); color: var(--success-dark); }
.badge-status.pending { background: var(--warning-bg); border: 1px solid var(--warning-border); color: var(--warning-dark); }
.badge-status.blocked { background: var(--danger-bg); border: 1px solid var(--danger-border); color: var(--danger-dark); }
.badge-status.inactive { background: #f1f5f9; border: 1px solid #cbd5e1; color: #475569; }
.badge-status.offline { background: var(--info-bg); border: 1px solid var(--info-border); color: var(--info-dark); }

/* --- DEVICE CHIP / CARD IN TABLE --- */
.device-card {
    background: #ffffff;
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-sm);
    padding: 0.6rem 0.85rem;
    margin-bottom: 0.4rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.75rem;
    min-width: 250px;
    box-shadow: var(--shadow-sm);
}

.device-card:last-child { margin-bottom: 0; }

.device-card-icon {
    width: 32px;
    height: 32px;
    border-radius: 6px;
    background: var(--primary-glow);
    color: var(--primary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1rem;
    flex-shrink: 0;
}

.device-card-info { flex: 1; min-width: 0; }
.device-alias { font-weight: 700; color: var(--text-heading); font-size: 0.83rem; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.device-meta { font-size: 0.7rem; color: var(--text-muted); font-family: 'JetBrains Mono', monospace; margin-top: 0.05rem; }

/* --- TOAST SYSTEM --- */
.toast-container {
    position: fixed;
    bottom: 24px;
    right: 24px;
    z-index: 1050;
}

/* --- TABS --- */
.nav-tabs-custom {
    border-bottom: 1px solid var(--border-subtle);
    display: flex;
    gap: 1rem;
    padding: 0 1.5rem;
}

.nav-tabs-custom .tab-link {
    border: none;
    background: transparent;
    padding: 1rem 0.5rem;
    font-weight: 600;
    color: var(--text-muted);
    position: relative;
    transition: color 0.15s;
}

.nav-tabs-custom .tab-link:hover {
    color: var(--text-heading);
}

.nav-tabs-custom .tab-link.active {
    color: var(--primary);
}

.nav-tabs-custom .tab-link.active::after {
    content: '';
    position: absolute;
    bottom: -1px;
    left: 0;
    right: 0;
    height: 2px;
    background-color: var(--primary);
}