:root {
    --primary: #4A90E2;
    --secondary: #EAF2F8;
    --dark: #2C3E50;
    --light: #F8F9F9;
    --white: #FFFFFF;
    --gray: #BDC3C7;
    --shadow: 0 5px 15px rgba(0,0,0,0.05);
    --shadow-hover: 0 10px 25px rgba(0,0,0,0.1);
    --transition: all 0.3s ease;
}

body {
    background-color: var(--light);
    color: var(--dark);
    font-family: 'Inter', 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    overflow-x: hidden;
}

/* Glassmorphism Auth Container */
.auth-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
}

.auth-card {
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    padding: 40px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.1);
    width: 100%;
    max-width: 450px;
    animation: slideUp 0.5s ease-out;
}

.form-control {
    border-radius: 10px;
    padding: 12px 20px;
    border: 1px solid var(--gray);
    transition: var(--transition);
}

.form-control:focus {
    box-shadow: 0 0 0 3px rgba(74, 144, 226, 0.2);
    border-color: var(--primary);
}

.btn-primary {
    background-color: var(--primary);
    border: none;
    border-radius: 10px;
    padding: 12px 20px;
    font-weight: 600;
    transition: var(--transition);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(74, 144, 226, 0.4);
}

/* Dashboard Layout */
.wrapper {
    display: flex;
    width: 100%;
}

.sidebar {
    width: 250px;
    height: 100vh;
    background: var(--white);
    box-shadow: var(--shadow);
    position: fixed;
    transition: var(--transition);
    z-index: 1000;
}

.sidebar .brand {
    padding: 20px;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
    text-align: center;
    border-bottom: 1px solid var(--secondary);
}

.sidebar .nav-link {
    color: var(--dark);
    padding: 15px 20px;
    margin: 5px 15px;
    border-radius: 10px;
    transition: var(--transition);
    font-weight: 500;
}

.sidebar .nav-link:hover, .sidebar .nav-link.active {
    background-color: var(--secondary);
    color: var(--primary);
}

.sidebar .nav-link i {
    width: 25px;
}

.main-content {
    margin-left: 250px;
    width: calc(100% - 250px);
    min-height: 100vh;
    padding: 20px;
    transition: var(--transition);
}

.top-navbar {
    background: var(--white);
    padding: 15px 30px;
    border-radius: 15px;
    box-shadow: var(--shadow);
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
}

/* User Navbar */
.user-navbar {
    background: var(--white);
    padding: 15px 30px;
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
}

/* Cards */
.stat-card {
    background: var(--white);
    border-radius: 15px;
    padding: 25px;
    box-shadow: var(--shadow);
    display: flex;
    align-items: center;
    justify-content: space-between;
    transition: var(--transition);
}

.stat-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

.stat-card .icon {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    background: var(--secondary);
    color: var(--primary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.8rem;
}

.ebook-card {
    background: var(--white);
    border-radius: 15px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
    height: 100%;
    display: flex;
    flex-direction: column;
}

.ebook-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-hover);
}

.ebook-card .cover {
    height: 250px;
    width: 100%;
    object-fit: cover;
    background: var(--secondary);
}

.ebook-card .content {
    padding: 20px;
    flex-grow: 1;
    display: flex;
    flex-direction: column;
}

.ebook-card .title {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 5px;
    color: var(--dark);
}

.ebook-card .author {
    color: var(--gray);
    font-size: 0.9rem;
    margin-bottom: 15px;
}

/* DataTables Styling */
.table-container {
    background: var(--white);
    border-radius: 15px;
    padding: 25px;
    box-shadow: var(--shadow);
}

.datatable-modern {
    width: 100% !important;
}

.datatable-modern thead th {
    background-color: var(--secondary);
    color: var(--dark);
    border: none;
    padding: 15px;
}

.datatable-modern tbody td {
    padding: 15px;
    vertical-align: middle;
    border-bottom: 1px solid var(--secondary);
}

/* Spinner & Toast */
#global-spinner {
    position: fixed;
    top: 0; left: 0; width: 100%; height: 100%;
    background: rgba(255,255,255,0.8);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    visibility: hidden;
    opacity: 0;
    transition: var(--transition);
}

#global-spinner.active {
    visibility: visible;
    opacity: 1;
}

.toast-container {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 9999;
}

/* Animations */
@keyframes slideUp {
    from { opacity: 0; transform: translateY(30px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.fade-in {
    animation: fadeIn 0.5s ease-in;
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: 50px 20px;
}

.empty-state i {
    font-size: 4rem;
    color: var(--gray);
    margin-bottom: 20px;
}

/* Responsive */
@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-100%);
    }
    .sidebar.show {
        transform: translateX(0);
    }
    .main-content {
        margin-left: 0;
        width: 100%;
    }
}