:root {
    /* --- Light Mode Colors --- */
    --bg-app: #f4f7fa;
    --bg-sidebar: #ffffff;
    --bg-panel: rgba(255, 255, 255, 0.7);
    --glass-border: rgba(0, 0, 0, 0.05);
    --glass-shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.07);
    
    --text-primary: #1e293b;
    --text-muted: #64748b;
    --text-on-accent: #ffffff;
    
    --accent-primary: #4f46e5;
    --accent-primary-hover: #4338ca;
    --accent-success: #10b981;
    --accent-success-hover: #059669;
    --accent-danger: #ef4444;
    --accent-danger-hover: #dc2626;
    --accent-info: #0ea5e9;
    --accent-info-hover: #0284c7;
    --accent-warning: #f59e0b;
    --accent-warning-hover: #d97706;
    --accent-secondary: #64748b;
    --accent-secondary-hover: #475569;
    
    --sidebar-width: 250px;
    --header-height: 60px;
    
    --row-alt: rgba(0, 0, 0, 0.02);
    --row-hover: rgba(0, 0, 0, 0.04);
}

[data-theme="dark"] {
    /* --- Dark Mode Colors --- */
    --bg-app: #0f172a;
    --bg-sidebar: #1e293b;
    --bg-panel: rgba(30, 41, 59, 0.7);
    --glass-border: rgba(255, 255, 255, 0.1);
    --glass-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.3);
    
    --text-primary: #f1f5f9;
    --text-muted: #94a3b8;
    --text-on-accent: #ffffff;
    
    --accent-primary: #6366f1;
    --accent-primary-hover: #818cf8;
    --accent-success: #34d399;
    --accent-success-hover: #10b981;
    --accent-danger: #f87171;
    --accent-danger-hover: #ef4444;
    --accent-info: #38bdf8;
    --accent-info-hover: #0ea5e9;
    --accent-warning: #fbbf24;
    --accent-warning-hover: #f59e0b;
    --accent-secondary: #94a3b8;
    --accent-secondary-hover: #64748b;
    
    --row-alt: rgba(255, 255, 255, 0.02);
    --row-hover: rgba(255, 255, 255, 0.04);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    font-size: 0.875rem;
    background-color: var(--bg-app);
    color: var(--text-primary);
    line-height: 1.5;
    transition: background-color 0.3s, color 0.3s;
    overflow-x: hidden;
}

/* Glass Surface Utility */
.glass-panel {
    background: var(--bg-panel);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--glass-border);
    box-shadow: var(--glass-shadow);
    border-radius: 1rem;
}

/* Base Layout Classes */
.layout-wrapper {
    display: flex;
    min-height: 100vh;
}

/* Sidebar */
.sidebar {
    width: var(--sidebar-width);
    background: var(--bg-sidebar);
    border-right: 1px solid var(--glass-border);
    display: flex;
    flex-direction: column;
    position: fixed;
    height: 100vh;
    z-index: 100;
    transition: width 0.3s ease, transform 0.3s ease;
}

/* Main Content */
.main-content {
    flex: 1;
    margin-left: var(--sidebar-width);
    display: flex;
    flex-direction: column;
    min-width: 0;
    transition: margin-left 0.3s ease;
}

/* Collapsed Sidebar State */
body.sidebar-collapsed {
    --sidebar-width: 80px;
}
body.sidebar-collapsed .sidebar-logo-text {
    display: none;
}
body.sidebar-collapsed .nav-text {
    display: none;
}
body.sidebar-collapsed .nav-group-title {
    display: none;
}
body.sidebar-collapsed .user-info {
    display: none;
}
body.sidebar-collapsed .nav-item {
    justify-content: center;
    padding: 0.75rem 0;
}
body.sidebar-collapsed .collapse-icon {
    transform: rotate(180deg);
}
body.sidebar-collapsed .desktop-toggle {
    position: relative !important;
    right: auto !important;
    margin: 0 auto;
}
body.sidebar-collapsed .sidebar-logo-container {
    display: none !important;
}

.desktop-toggle {
    transition: background 0.2s, color 0.2s;
}
.collapse-icon {
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.top-header {
    height: var(--header-height);
    padding: 0 2rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: var(--bg-panel);
    backdrop-filter: blur(8px);
    border-bottom: 1px solid var(--glass-border);
    position: sticky;
    top: 0;
    z-index: 90;
}

.page-body {
    padding: 2rem;
    flex: 1;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    border-radius: 0.5rem;
    font-size: 0.875rem;
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    transition: all 0.2s;
    border: 1px solid transparent;
}

.btn-primary {
    background: var(--accent-primary);
    color: var(--text-on-accent);
}
.btn-primary:hover {
    background: var(--accent-primary-hover);
    transform: translateY(-1px);
}

.btn-info {
    background: var(--accent-info);
    color: var(--text-on-accent);
}
.btn-info:hover {
    background: var(--accent-info-hover);
    transform: translateY(-1px);
}

.btn-danger {
    background: var(--accent-danger);
    color: var(--text-on-accent);
}
.btn-danger:hover {
    background: var(--accent-danger-hover);
    transform: translateY(-1px);
}

.btn-success {
    background: var(--accent-success);
    color: var(--text-on-accent);
}
.btn-success:hover {
    background: var(--accent-success-hover);
    transform: translateY(-1px);
}

.btn-secondary {
    background: var(--accent-secondary);
    color: var(--text-on-accent);
}
.btn-secondary:hover {
    background: var(--accent-secondary-hover);
    transform: translateY(-1px);
}

.btn-outline {
    background: transparent;
    border: 1px solid var(--glass-border);
    color: var(--text-primary);
}
.btn-outline:hover {
    background: var(--glass-border);
}

.btn-outline-danger {
    background: transparent;
    border: 1px solid rgba(239, 68, 68, 0.3);
    color: var(--accent-danger);
}
.btn-outline-danger:hover {
    background: rgba(239, 68, 68, 0.1);
}

/* Forms */
.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
}

.form-label {
    font-weight: 500;
    color: var(--text-primary);
    font-size: 0.875rem;
}

.form-control {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 1px solid var(--glass-border);
    border-radius: 0.5rem;
    background: var(--bg-panel);
    color: var(--text-primary);
    font-family: inherit;
    transition: all 0.2s;
}

.form-control:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.form-actions {
    display: flex;
    justify-content: flex-end;
    gap: 1rem;
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--glass-border);
}

/* Tables */
.table-container {
    width: 100%;
    overflow-x: auto;
    border-radius: 0.75rem;
}

table {
    width: 100%;
    border-collapse: collapse;
}

th {
    text-align: left;
    padding: 0.875rem 1rem;
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
    border-bottom: 1px solid var(--glass-border);
}

td {
    padding: 0.75rem 1rem;
    border-bottom: 1px solid var(--glass-border);
    vertical-align: middle;
}

tbody tr {
    transition: background-color 0.2s;
}

tbody tr:nth-child(even) {
    background: var(--row-alt);
}

tbody tr:hover {
    background: var(--row-hover);
}

/* Forms */
.form-group {
    margin-bottom: 1.5rem;
}

label {
    display: block;
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.form-input {
    width: 100%;
    padding: 0.625rem 0.875rem;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--glass-border);
    border-radius: 0.5rem;
    color: var(--text-primary);
    font-size: 0.875rem;
    transition: border-color 0.2s;
}

.form-input:focus {
    outline: none;
    border-color: var(--accent-primary);
    background: rgba(255, 255, 255, 0.05);
}

/* Responsive */
@media (max-width: 1024px) {
    .sidebar {
        transform: translateX(-100%);
    }
    .main-content {
        margin-left: 0;
    }
    .sidebar.open {
        transform: translateX(0);
    }
}