/* Digital Library - Elegant & Modern Design */
:root {
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --secondary: #8b5cf6;
    --accent: #ec4899;
    --dark: #1e293b;
    --dark-light: #334155;
    --gray: #64748b;
    --gray-light: #f1f5f9;
    --white: #ffffff;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

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

body {
    font-family: 'Inter', 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    background-attachment: fixed;
    min-height: 100vh;
    color: var(--dark);
}

/* Glass morphism effect */
.glass {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

/* Smooth animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.animate-fade-in {
    animation: fadeIn 0.6s ease-out;
}

.animate-slide-in {
    animation: slideIn 0.6s ease-out;
}

/* Card hover effects */
.card-hover {
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.card-hover:hover {
    transform: translateY(-8px) scale(1.02);
    box-shadow: var(--shadow-lg);
}

/* Button styles */
.btn-primary {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.btn-primary::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.5s;
}

.btn-primary:hover::before {
    left: 100%;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(99, 102, 241, 0.3);
}

/* Navigation */
.nav-glass {
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
}

/* Book card styles */
.book-card {
    background: var(--white);
    border-radius: 16px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
}

.book-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary), var(--secondary), var(--accent));
    opacity: 0;
    transition: opacity 0.3s;
}

.book-card:hover::before {
    opacity: 1;
}

.book-card:hover {
    transform: translateY(-12px);
    box-shadow: var(--shadow-lg);
}

.book-cover {
    position: relative;
    overflow: hidden;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.book-cover img {
    transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.book-card:hover .book-cover img {
    transform: scale(1.1);
}

/* Responsive utilities */
@media (max-width: 640px) {
    .mobile-hidden {
        display: none;
    }
    
    .mobile-full {
        width: 100%;
    }
}

/* Loading skeleton */
.skeleton {
    background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
    background-size: 200% 100%;
    animation: loading 1.5s infinite;
}

@keyframes loading {
    0% {
        background-position: 200% 0;
    }
    100% {
        background-position: -200% 0;
    }
}

/* Custom scrollbar */
::-webkit-scrollbar {
    width: 10px;
}

::-webkit-scrollbar-track {
    background: var(--gray-light);
}

::-webkit-scrollbar-thumb {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    border-radius: 5px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--primary-dark);
}

/* Form inputs */
.form-input {
    transition: all 0.3s ease;
    border: 2px solid #e2e8f0;
}

.form-input:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
    transform: translateY(-2px);
}

/* Badge styles */
.badge {
    display: inline-flex;
    align-items: center;
    padding: 0.25rem 0.75rem;
    border-radius: 9999px;
    font-size: 0.75rem;
    font-weight: 600;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: var(--white);
}

/* Empty state */
.empty-state {
    background: var(--white);
    border-radius: 24px;
    padding: 4rem 2rem;
    text-align: center;
    box-shadow: var(--shadow);
}

/* Gradient text */
.gradient-text {
    background: linear-gradient(135deg, var(--primary), var(--secondary), var(--accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}