:root {
    --bg-app: #F3F4F6;
    --surface-main: #FFFFFF;
    --text-primary: #111827;
    --text-secondary: #6B7280;
    --border-color: #E5E7EB;
    
    /* Branding VetCare Admin */
    --brand-primary: #FF7B54;
    --brand-dark: #cc6243;
    --brand-blue: #4A90E2;
    
    /* Status Colors */
    --success-bg: #D1FAE5;
    --success-text: #065F46;
    --warning-bg: #FEF3C7;
    --warning-text: #92400E;
    --danger-bg: #FEE2E2;
    --danger-text: #991B1B;

    --font-family: 'Inter', system-ui, -apple-system, sans-serif;
    --radius-md: 12px;
    --radius-lg: 20px;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.05);
    --shadow-md: 0 4px 20px -5px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 10px 40px -10px rgba(0, 0, 0, 0.12);
    
    /* Gradients */
    --grad-primary: linear-gradient(135deg, #FF7B54 0%, #FFB26B 100%);
    --grad-blue: linear-gradient(135deg, #4A90E2 0%, #63B3ED 100%);
    --grad-dark: linear-gradient(135deg, #2D3748 0%, #4A5568 100%);
}

* { margin: 0; padding: 0; box-sizing: border-box; font-family: var(--font-family); }

body { background-color: var(--bg-app); color: var(--text-primary); display: flex; height: 100vh; overflow: hidden; }

/* Sidebar */
.sidebar { width: 260px; background-color: var(--surface-main); border-right: 1px solid var(--border-color); display: flex; flex-direction: column; }
.sidebar-header { padding: 24px; border-bottom: 1px solid var(--border-color); display: flex; align-items: center; gap: 12px; }
.logo-icon { color: var(--brand-primary); }
.logo-text { font-size: 1.25rem; font-weight: 800; letter-spacing: -0.5px; }
.badge-admin { background: var(--brand-blue); color: white; font-size: 0.65rem; padding: 2px 6px; border-radius: 4px; font-weight: bold; letter-spacing: 0.5px; text-transform: uppercase;}

.nav-menu { flex: 1; padding: 20px 0; overflow-y: auto; }
.nav-item { padding: 12px 24px; display: flex; align-items: center; gap: 12px; color: var(--text-secondary); text-decoration: none; font-weight: 500; transition: 0.2s; cursor: pointer; }
.nav-item:hover { background-color: #F9FAFB; color: var(--brand-primary); }
.nav-item.active { background-color: #FFF2EE; color: var(--brand-primary); border-right: 3px solid var(--brand-primary); font-weight: 600; }
.nav-item i { width: 20px; height: 20px; }

/* Main Content Area */
.main-wrapper { flex: 1; display: flex; flex-direction: column; overflow-y: auto; }

/* Top Header */
.top-header { background: var(--surface-main); padding: 16px 32px; border-bottom: 1px solid var(--border-color); display: flex; justify-content: space-between; align-items: center; position: sticky; top:0; z-index: 10;}
.search-bar { display: flex; align-items: center; background: var(--bg-app); padding: 8px 16px; border-radius: 8px; width: 400px; border: 1px solid transparent;}
.search-bar:focus-within { border-color: var(--brand-blue); background: var(--surface-main); }
.search-bar input { border: none; background: transparent; outline: none; margin-left: 10px; width: 100%; color: var(--text-primary); font-size: 0.95rem; }

.user-profile { display: flex; align-items: center; gap: 12px; }
.avatar { width: 40px; height: 40px; border-radius: 50%; background: var(--brand-blue); color: white; display: flex; justify-content: center; align-items: center; font-weight: bold; }

/* Dashboard Content */
.content { padding: 32px; }
.page-title { display: flex; justify-content: space-between; align-items: center; margin-bottom: 24px; }
.page-title h1 { font-size: 1.5rem; font-weight: 700; }
.btn-primary { background: var(--brand-primary); color: white; border: none; padding: 10px 20px; border-radius: 8px; font-weight: 600; cursor: pointer; display: flex; gap: 8px; align-items: center; transition: 0.2s;}
.btn-primary:hover { background: var(--brand-dark); }

/* KPI Grid */
.kpi-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; margin-bottom: 32px; }
.kpi-card { background: var(--surface-main); padding: 24px; border-radius: var(--radius-md); box-shadow: var(--shadow-sm); border: 1px solid var(--border-color); }
.kpi-header { display: flex; justify-content: space-between; align-items: center; color: var(--text-secondary); font-size: 0.875rem; font-weight: 500; margin-bottom: 12px; }
.kpi-value { font-size: 1.875rem; font-weight: 700; color: var(--text-primary); display: flex; align-items: baseline; gap: 8px;}
.kpi-trend.positive { font-size: 0.8rem; color: var(--success-text); font-weight: 600; display:flex; align-items:center;}

/* Table Section */
.card-section { background: var(--surface-main); border-radius: var(--radius-lg); box-shadow: var(--shadow-md); border: 1px solid var(--border-color); overflow: hidden; }
.card-header { padding: 20px 24px; border-bottom: 1px solid var(--border-color); display: flex; justify-content: space-between; align-items: center; }
.card-header h2 { font-size: 1.1rem; font-weight: 600; }

table { width: 100%; border-collapse: collapse; }
th { text-align: left; padding: 16px 24px; font-size: 0.75rem; text-transform: uppercase; color: var(--text-secondary); font-weight: 600; letter-spacing: 0.5px; background: #F9FAFB; border-bottom: 1px solid var(--border-color); }
td { padding: 16px 24px; font-size: 0.9rem; border-bottom: 1px solid var(--border-color); color: var(--text-primary); vertical-align: middle; }
tr:last-child td { border-bottom: none; }
tr:hover td { background: #F9FAFB; }

.patient-info { display: flex; align-items: center; gap: 12px; }
.pet-avatar { width: 36px; height: 36px; border-radius: 8px; object-fit: cover; }
.pet-name { font-weight: 600; display: block; margin-bottom: 2px;}
.owner-name { font-size: 0.8rem; color: var(--text-secondary); }

/* Status Badges */
.status { padding: 4px 10px; border-radius: 100px; font-size: 0.75rem; font-weight: 600; display: inline-flex; align-items: center; gap: 6px; }
.status-green { background: var(--success-bg); color: var(--success-text); }
.status-red { background: var(--danger-bg); color: var(--danger-text); }
.status-yellow { background: var(--warning-bg); color: var(--warning-text); }

.action-btn { background: transparent; border: none; color: var(--text-secondary); cursor: pointer; padding: 8px; border-radius: 8px; transition:0.2s; display: inline-flex; align-items: center; justify-content: center; }
.action-btn:hover { background: #F3F4F6; color: var(--brand-blue); transform: scale(1.1); }

/* Progress Bar for Inventory */
.stock-bar-container { width: 100%; height: 6px; background: #EDF2F7; border-radius: 10px; margin-top: 8px; overflow: hidden; }
.stock-bar-fill { height: 100%; border-radius: 10px; transition: width 0.5s ease-out; }

/* Grid Improvements */
.dashboard-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 24px; }

/* Quick Actions Card */
.quick-card { background: white; padding: 20px; border-radius: var(--radius-md); border: 1px solid var(--border-color); transition: 0.3s; cursor: pointer; }
.quick-card:hover { border-color: var(--brand-primary); transform: translateY(-5px); box-shadow: var(--shadow-lg); }

/* Billing Table Specifics */
.invoice-badge { font-size: 0.7rem; font-weight: 700; padding: 4px 12px; border-radius: 6px; text-transform: uppercase; }

/* Glassmorphism utility */
.glass { background: rgba(255, 255, 255, 0.8); backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px); border: 1px solid rgba(255, 255, 255, 0.3); }

/* Animations */
@keyframes fadeIn { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: translateY(0); } }
.content > * { animation: fadeIn 0.4s ease-out forwards; }