:root {
    --primary-color: #4e73df;
    --primary-dark: #224abe;
    --secondary-color: #858796;
    --success-color: #1cc88a;
    --info-color: #36b9cc;
    --warning-color: #f6c23e;
    --danger-color: #e74a3b;
    --light-color: #f8f9fc;
    --dark-color: #5a5c69;
    --bg-body: #f3f4f6;
    --bg-card: #ffffff;
    --text-main: #2d3748;
    --text-muted: #718096;
    --border-color: #e3e6f0;
    --sidebar-width: 250px;
    --header-height: 60px;
    --transition-speed: 0.3s;
    --shadow-sm: 0 0.125rem 0.25rem 0 rgba(58, 59, 69, 0.2);
    --shadow-md: 0 0.15rem 1.75rem 0 rgba(58, 59, 69, 0.15);
}

/* Dark Mode Variables (Optional, can be toggled) */
[data-theme="dark"] {
    --bg-body: #1a1c23;
    --bg-card: #24262d;
    --text-main: #e2e8f0;
    --text-muted: #a0aec0;
    --border-color: #2d3748;
}

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

body {
    font-family: 'Quicksand', 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--bg-body);
    color: var(--text-main);
    font-size: 1rem;
    line-height: 1.5;
    overflow-x: hidden;
}

a {
    text-decoration: none;
    color: var(--primary-color);
    transition: color var(--transition-speed);
}

a:hover {
    color: var(--primary-dark);
}

/* Layout */
.wrapper {
    display: flex;
    min-height: 100vh;
    width: 100%;
}

/* Sidebar */
.sidebar {
    width: var(--sidebar-width);
    background: linear-gradient(180deg, #4e73df 10%, #224abe 100%);
    color: #fff;
    position: fixed;
    top: 0;
    left: 0;
    height: 100vh;
    z-index: 1000;
    transition: all var(--transition-speed);
    overflow-y: auto;
    box-shadow: var(--shadow-md);
}

.sidebar-brand {
    height: var(--header-height);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.sidebar-brand i {
    margin-right: 0.5rem;
    font-size: 1.5rem;
}

.sidebar-menu {
    padding: 1rem 0;
    list-style: none;
}

.sidebar-heading {
    color: rgba(255, 255, 255, 0.4);
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    padding: 0.75rem 1rem;
    margin-top: 1rem;
}

.nav-item {
    position: relative;
}

.nav-link {
    display: flex;
    align-items: center;
    padding: 0.75rem 1rem;
    color: rgba(255, 255, 255, 0.8);
    font-weight: 600;
    transition: all 0.2s;
}

.nav-link:hover, .nav-link.active {
    color: #fff;
    background: rgba(255, 255, 255, 0.1);
    border-left: 4px solid #fff;
}

.nav-link i {
    margin-right: 0.75rem;
    width: 20px;
    text-align: center;
}

/* Main Content */
.main-content {
    flex: 1;
    margin-left: var(--sidebar-width);
    padding: 1.5rem;
    transition: margin-left var(--transition-speed);
    width: calc(100% - var(--sidebar-width));
}

/* Header/Navbar inside Main Content (Mobile Toggle) */
.top-bar {
    display: none; /* Hidden on desktop by default if not needed, or used for user profile */
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
    background: var(--bg-card);
    padding: 0.5rem 1rem;
    border-radius: 0.5rem;
    box-shadow: var(--shadow-sm);
}

.hamburger {
    display: none;
    background: none;
    border: none;
    color: var(--text-main);
    font-size: 1.5rem;
    cursor: pointer;
}

/* Cards */
.card {
    background-color: var(--bg-card);
    border-radius: 0.5rem;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    margin-bottom: 1.5rem;
    overflow: hidden;
}

.card-header {
    padding: 1rem 1.25rem;
    background-color: rgba(0, 0, 0, 0.03);
    border-bottom: 1px solid var(--border-color);
    font-weight: 700;
    color: var(--primary-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.card-body {
    padding: 1.25rem;
}

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

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: var(--text-main);
}

.form-control {
    display: block;
    width: 100%;
    padding: 0.5rem 0.75rem;
    font-size: 1rem;
    line-height: 1.5;
    color: var(--text-main);
    background-color: var(--bg-card);
    background-clip: padding-box;
    border: 1px solid var(--border-color);
    border-radius: 0.35rem;
    transition: border-color 0.15s ease-in-out, box-shadow 0.15s ease-in-out;
}

.form-control:focus {
    border-color: var(--primary-color);
    outline: 0;
    box-shadow: 0 0 0 0.2rem rgba(78, 115, 223, 0.25);
}

.form-select {
    display: block;
    width: 100%;
    padding: 0.5rem 2.25rem 0.5rem 0.75rem;
    font-size: 1rem;
    line-height: 1.5;
    color: var(--text-main);
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 0.35rem;
    appearance: none;
}

/* Buttons */
.btn {
    display: inline-block;
    font-weight: 600;
    text-align: center;
    vertical-align: middle;
    user-select: none;
    padding: 0.5rem 1rem;
    font-size: 1rem;
    line-height: 1.5;
    border-radius: 0.35rem;
    transition: color 0.15s ease-in-out, background-color 0.15s ease-in-out, border-color 0.15s ease-in-out, box-shadow 0.15s ease-in-out;
    cursor: pointer;
    border: 1px solid transparent;
}

.btn-primary {
    color: #fff;
    background-color: var(--primary-color);
    border-color: var(--primary-color);
}

.btn-primary:hover {
    background-color: var(--primary-dark);
    border-color: var(--primary-dark);
}

.btn-success {
    color: #fff;
    background-color: var(--success-color);
    border-color: var(--success-color);
}

.btn-danger {
    color: #fff;
    background-color: var(--danger-color);
    border-color: var(--danger-color);
}

.btn-warning {
    color: #fff;
    background-color: var(--warning-color);
    border-color: var(--warning-color);
}

.btn-info {
    color: #fff;
    background-color: var(--info-color);
    border-color: var(--info-color);
}

.btn-block {
    display: block;
    width: 100%;
}

/* Tables */
.table-responsive {
    display: block;
    width: 100%;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
}

.table {
    width: 100%;
    margin-bottom: 1rem;
    color: var(--text-main);
    border-collapse: collapse;
}

.table th,
.table td {
    padding: 0.75rem;
    vertical-align: top;
    border-top: 1px solid var(--border-color);
}

.table thead th {
    vertical-align: bottom;
    border-bottom: 2px solid var(--border-color);
    background-color: rgba(0, 0, 0, 0.02);
    color: var(--primary-color);
    text-transform: uppercase;
    font-size: 0.85rem;
}

.table-striped tbody tr:nth-of-type(odd) {
    background-color: rgba(0, 0, 0, 0.02);
}

.table-hover tbody tr:hover {
    background-color: rgba(0, 0, 0, 0.04);
}

/* Badges */
.badge {
    display: inline-block;
    padding: 0.25em 0.6em;
    font-size: 75%;
    font-weight: 700;
    line-height: 1;
    text-align: center;
    white-space: nowrap;
    vertical-align: baseline;
    border-radius: 0.35rem;
    color: #fff;
}

.bg-success { background-color: var(--success-color); }
.bg-danger { background-color: var(--danger-color); }
.bg-warning { background-color: var(--warning-color); }
.bg-info { background-color: var(--info-color); }
.bg-primary { background-color: var(--primary-color); }

/* Utilities */
.text-center { text-align: center; }
.text-right { text-align: right; }
.mb-3 { margin-bottom: 1rem; }
.mt-3 { margin-top: 1rem; }
.p-3 { padding: 1rem; }
.d-flex { display: flex; }
.justify-content-between { justify-content: space-between; }
.align-items-center { align-items: center; }
.w-100 { width: 100%; }

/* Responsive */
@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-100%);
    }
    
    .sidebar.active {
        transform: translateX(0);
    }
    
    .main-content {
        margin-left: 0;
        width: 100%;
    }
    
    .top-bar {
        display: flex;
    }
    
    .hamburger {
        display: block;
    }
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: #f1f1f1; 
}
 
::-webkit-scrollbar-thumb {
    background: #888; 
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: #555; 
}

/* Specific Page Styles */
.welcome-section {
    background: linear-gradient(45deg, #4e73df, #224abe);
    color: white;
    border: none;
}

.welcome-section .btn {
    background: rgba(255,255,255,0.2);
    border: 1px solid rgba(255,255,255,0.3);
    color: white;
}

.welcome-section .btn:hover {
    background: rgba(255,255,255,0.3);
}

.stat-card {
    border-left: 4px solid var(--primary-color);
}

.stat-card.success { border-left-color: var(--success-color); }
.stat-card.warning { border-left-color: var(--warning-color); }
.stat-card.danger { border-left-color: var(--danger-color); }

.input-group {
    display: flex;
    width: 100%;
}

.input-group .form-control {
    border-top-right-radius: 0;
    border-bottom-right-radius: 0;
}

.input-group .btn {
    border-top-left-radius: 0;
    border-bottom-left-radius: 0;
}