/**
 * BookStore Premium Stylesheet
 * Modern, animated, world-class UI/UX design
 */

/* ===== ROOT VARIABLES ===== */
:root {
    --primary-color: #8B5CF6;
    --secondary-color: #EC4899;
    --accent-color: #F59E0B;
    --success-color: #10B981;
    --danger-color: #EF4444;
    --warning-color: #F59E0B;
    --info-color: #3B82F6;
    --dark-color: #1F2937;
    --darker-color: #111827;
    --light-color: #F9FAFB;
    --border-color: #E5E7EB;
    --text-color: #1F2937;
    --text-secondary: #6B7280;
    --text-light: #9CA3AF;
    --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
}

/* ===== RESET & BASE ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background: #FFFFFF;
    overflow-x: hidden;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

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

a:hover {
    color: var(--secondary-color);
}

/* ===== CONTAINER ===== */
.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ===== SMOOTH SCROLL ===== */
html {
    scroll-behavior: smooth;
}

/* ===== NAVIGATION ===== */
.navbar {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    padding: 1rem 0;
    box-shadow: var(--shadow-lg);
    position: sticky;
    top: 0;
    z-index: 1000;
    backdrop-filter: blur(10px);
}

.nav-wrapper {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.75rem;
    font-weight: 800;
    color: white;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: var(--transition);
}

.logo:hover {
    transform: scale(1.05);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2.5rem;
    align-items: center;
}

.nav-menu a {
    color: white;
    font-weight: 600;
    font-size: 0.95rem;
    position: relative;
    padding: 0.5rem 0;
}

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 3px;
    background: white;
    border-radius: 2px;
    transition: var(--transition);
}

.nav-menu a:hover::after {
    width: 100%;
}

.cart-link {
    position: relative;
    background: rgba(255, 255, 255, 0.2);
    padding: 0.5rem 1rem;
    border-radius: var(--radius-lg);
    transition: var(--transition);
}

.cart-link:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

.cart-badge {
    position: absolute;
    top: -8px;
    right: -8px;
    background: linear-gradient(135deg, var(--danger-color), #DC2626);
    color: white;
    border-radius: 50%;
    min-width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.75rem;
    font-weight: 700;
    box-shadow: 0 4px 8px rgba(239, 68, 68, 0.4);
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.1); }
}

.mobile-menu-toggle {
    display: none;
    background: rgba(255, 255, 255, 0.2);
    border: none;
    color: white;
    font-size: 1.5rem;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: var(--radius-sm);
    transition: var(--transition);
}

.mobile-menu-toggle:hover {
    background: rgba(255, 255, 255, 0.3);
}

/* Dropdown */
.dropdown {
    position: relative;
}

.dropdown-toggle {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.dropdown-menu {
    display: none;
    position: absolute;
    top: calc(100% + 1rem);
    left: 50%;
    transform: translateX(-50%);
    background: white;
    min-width: 220px;
    box-shadow: var(--shadow-xl);
    border-radius: var(--radius-md);
    padding: 0.75rem;
    list-style: none;
    animation: dropdownSlide 0.3s ease;
}

@keyframes dropdownSlide {
    from {
        opacity: 0;
        transform: translateX(-50%) translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateX(-50%) translateY(0);
    }
}

.dropdown:hover .dropdown-menu {
    display: block;
}

.dropdown-menu li {
    padding: 0;
}

.dropdown-menu a {
    color: var(--text-color);
    padding: 0.75rem 1rem;
    display: block;
    border-radius: var(--radius-sm);
    font-weight: 500;
    transition: var(--transition);
}

.dropdown-menu a:hover {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    transform: translateX(5px);
}

/* ===== BUTTONS ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.875rem 1.75rem;
    border-radius: var(--radius-lg);
    font-weight: 600;
    font-size: 0.95rem;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    text-decoration: none;
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.3);
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.btn:hover::before {
    width: 300px;
    height: 300px;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    box-shadow: 0 4px 12px rgba(139, 92, 246, 0.4);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(139, 92, 246, 0.5);
}

.btn-success {
    background: linear-gradient(135deg, var(--success-color), #059669);
    color: white;
    box-shadow: 0 4px 12px rgba(16, 185, 129, 0.4);
}

.btn-danger {
    background: linear-gradient(135deg, var(--danger-color), #DC2626);
    color: white;
    box-shadow: 0 4px 12px rgba(239, 68, 68, 0.4);
}

.btn-outline {
    background: transparent;
    border: 2px solid var(--primary-color);
    color: var(--primary-color);
    box-shadow: none;
}

.btn-outline:hover {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border-color: transparent;
}

.btn-sm {
    padding: 0.625rem 1.25rem;
    font-size: 0.875rem;
}

.btn-lg {
    padding: 1.125rem 2.25rem;
    font-size: 1.125rem;
    border-radius: var(--radius-xl);
}

.btn-block {
    width: 100%;
}

/* ===== ANIMATED TOOLTIPS ===== */
[data-tooltip] {
    position: relative;
}

[data-tooltip]::after {
    content: attr(data-tooltip);
    position: absolute;
    bottom: calc(100% + 10px);
    left: 50%;
    transform: translateX(-50%) translateY(-5px);
    background: var(--darker-color);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    white-space: nowrap;
    opacity: 0;
    pointer-events: none;
    transition: var(--transition);
    z-index: 1000;
}

[data-tooltip]:hover::after {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
}

/* ===== ALERTS ===== */
.alert {
    padding: 1rem 1.5rem;
    border-radius: var(--radius-md);
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 1rem;
    animation: slideIn 0.3s ease;
}

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

.alert-success {
    background: linear-gradient(135deg, #ECFDF5, #D1FAE5);
    color: #065F46;
    border-left: 4px solid var(--success-color);
}

.alert-error {
    background: linear-gradient(135deg, #FEF2F2, #FEE2E2);
    color: #991B1B;
    border-left: 4px solid var(--danger-color);
}

/* ===== HERO SECTION ===== */
.hero {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    padding: 6rem 0;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.05'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

.hero-content {
    position: relative;
    z-index: 1;
}

.hero-title {
    font-size: 3.5rem;
    margin-bottom: 1.5rem;
    font-weight: 800;
    line-height: 1.2;
    animation: fadeInUp 0.8s ease;
}

.hero-subtitle {
    font-size: 1.375rem;
    margin-bottom: 2.5rem;
    opacity: 0.95;
    font-weight: 400;
    animation: fadeInUp 0.8s ease 0.2s both;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ===== SECTIONS ===== */
section {
    padding: 5rem 0;
}

.section-title {
    font-size: 2.5rem;
    margin-bottom: 3rem;
    text-align: center;
    font-weight: 800;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 3rem;
}

/* ===== CATEGORIES ===== */
.categories-section {
    background: linear-gradient(180deg, #FFFFFF 0%, var(--light-color) 100%);
}

.categories-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 2rem;
}

.category-card {
    background: white;
    padding: 2.5rem 2rem;
    border-radius: var(--radius-xl);
    text-align: center;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    color: var(--text-color);
    position: relative;
    overflow: hidden;
}

.category-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    transform: scaleX(0);
    transition: var(--transition);
}

.category-card:hover::before {
    transform: scaleX(1);
}

.category-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

.category-card i {
    font-size: 3.5rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 1.25rem;
    display: inline-block;
    transition: var(--transition);
}

.category-card:hover i {
    transform: scale(1.1) rotate(5deg);
}

.category-card h3 {
    margin-bottom: 0.75rem;
    color: var(--text-color);
    font-size: 1.25rem;
    font-weight: 700;
}

.category-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* ===== ANIMATED BOOK CARDS ===== */
.books-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 2.5rem;
}

.book-card {
    background: white;
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    position: relative;
    height: 100%;
    display: flex;
    flex-direction: column;
}

.book-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    opacity: 0;
    transition: var(--transition);
    z-index: 1;
}

.book-card:hover::before {
    opacity: 0.05;
}

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

.book-cover {
    position: relative;
    width: 100%;
    height: 380px;
    overflow: hidden;
    background: linear-gradient(135deg, #F3F4F6, #E5E7EB);
}

.book-cover img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition);
}

.book-card:hover .book-cover img {
    transform: scale(1.08);
}

.book-cover-placeholder {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    position: relative;
}

.book-cover-placeholder::before {
    content: '';
    position: absolute;
    width: 150px;
    height: 150px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.2);
    animation: floating 3s infinite ease-in-out;
}

@keyframes floating {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-20px); }
}

.book-cover-placeholder i {
    font-size: 5rem;
    color: rgba(255, 255, 255, 0.6);
    position: relative;
    z-index: 1;
}

.book-badge {
    position: absolute;
    top: 16px;
    right: 16px;
    background: linear-gradient(135deg, var(--success-color), #059669);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: var(--radius-lg);
    font-size: 0.875rem;
    font-weight: 700;
    box-shadow: 0 4px 12px rgba(16, 185, 129, 0.4);
    z-index: 2;
    animation: bounce 2s infinite;
}

@keyframes bounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-5px); }
}

.book-info {
    padding: 1.75rem;
    flex: 1;
    display: flex;
    flex-direction: column;
}

.book-title {
    font-size: 1.25rem;
    margin-bottom: 0.75rem;
    line-height: 1.4;
    font-weight: 700;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.book-title a {
    color: var(--text-color);
    transition: var(--transition);
}

.book-title a:hover {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.book-author {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.book-category {
    color: var(--primary-color);
    font-size: 0.875rem;
    margin-bottom: 1.25rem;
    font-weight: 600;
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background: linear-gradient(135deg, rgba(139, 92, 246, 0.1), rgba(236, 72, 153, 0.1));
    border-radius: var(--radius-sm);
}

.book-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: auto;
    padding-top: 1.25rem;
    border-top: 2px solid var(--border-color);
}

.book-price {
    font-size: 1.5rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* ===== FEATURES ===== */
.features {
    background: linear-gradient(180deg, var(--light-color) 0%, #FFFFFF 100%);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2.5rem;
}

.feature-card {
    background: white;
    padding: 3rem 2rem;
    border-radius: var(--radius-xl);
    text-align: center;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    width: 200px;
    height: 200px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    opacity: 0.05;
    top: -100px;
    right: -100px;
    transition: var(--transition);
}

.feature-card:hover::before {
    transform: scale(1.5);
    opacity: 0.1;
}

.feature-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

.feature-card i {
    font-size: 4rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 1.5rem;
    display: inline-block;
    transition: var(--transition);
}

.feature-card:hover i {
    transform: scale(1.2) rotate(10deg);
}

.feature-card h3 {
    margin-bottom: 1rem;
    font-size: 1.375rem;
    font-weight: 700;
}

.feature-card p {
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ===== BOOKS PAGE LAYOUT ===== */
.page-header {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    padding: 4rem 0;
    text-align: center;
    margin-bottom: 3rem;
}

.page-header h1 {
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: 1rem;
}

.books-layout {
    display: grid;
    grid-template-columns: 280px 1fr;
    gap: 3rem;
}

.books-sidebar {
    position: sticky;
    top: 100px;
    height: fit-content;
}

.filter-section {
    background: white;
    padding: 2rem;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    margin-bottom: 2rem;
}

.filter-section h3 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    color: var(--text-color);
}

.search-form {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.form-input {
    width: 100%;
    padding: 0.875rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 0.95rem;
    transition: var(--transition);
}

.form-input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 4px rgba(139, 92, 246, 0.1);
}

.category-filter {
    list-style: none;
}

.category-filter li {
    margin-bottom: 0.5rem;
}

.category-filter a {
    display: block;
    padding: 0.875rem 1rem;
    color: var(--text-color);
    border-radius: var(--radius-md);
    transition: var(--transition);
    font-weight: 500;
}

.category-filter a:hover,
.category-filter a.active {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    transform: translateX(5px);
}

.search-info {
    padding: 1.5rem;
    background: linear-gradient(135deg, rgba(139, 92, 246, 0.1), rgba(236, 72, 153, 0.1));
    border-radius: var(--radius-md);
    margin-bottom: 2rem;
    border-left: 4px solid var(--primary-color);
}

.no-results {
    text-align: center;
    padding: 5rem 2rem;
    background: white;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
}

.no-results i {
    font-size: 5rem;
    color: var(--text-light);
    margin-bottom: 1.5rem;
}

.no-results h3 {
    font-size: 2rem;
    margin-bottom: 1rem;
    color: var(--text-color);
}

.no-results p {
    color: var(--text-secondary);
    margin-bottom: 2rem;
    font-size: 1.125rem;
}

/* ===== PAGINATION ===== */
.pagination {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 0.75rem;
    margin-top: 4rem;
    flex-wrap: wrap;
}

.pagination-btn,
.pagination-number {
    padding: 0.875rem 1.25rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-color);
    font-weight: 600;
    transition: var(--transition);
    background: white;
}

.pagination-btn:hover,
.pagination-number:hover {
    border-color: var(--primary-color);
    background: linear-gradient(135deg, rgba(139, 92, 246, 0.1), rgba(236, 72, 153, 0.1));
    transform: translateY(-2px);
}

.pagination-number.active {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border-color: transparent;
    box-shadow: 0 4px 12px rgba(139, 92, 246, 0.4);
}

.pagination-numbers {
    display: flex;
    gap: 0.5rem;
}

/* ===== FOOTER ===== */
.footer {
    background: linear-gradient(135deg, #1F2937 0%, #111827 100%);
    color: white;
    padding: 4rem 0 1.5rem;
    margin-top: 5rem;
    position: relative;
}

.footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 3rem;
    margin-bottom: 3rem;
}

.footer-section h3,
.footer-section h4 {
    margin-bottom: 1.5rem;
    font-weight: 700;
    font-size: 1.25rem;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.75rem;
}

.footer-section a {
    color: rgba(255, 255, 255, 0.8);
    transition: var(--transition);
}

.footer-section a:hover {
    color: white;
    padding-left: 5px;
}

.social-links {
    display: flex;
    gap: 1rem;
    margin-top: 1.5rem;
}

.social-links a {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.1);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
    font-size: 1.25rem;
}

.social-links a:hover {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    transform: translateY(-5px);
    box-shadow: 0 8px 16px rgba(139, 92, 246, 0.4);
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.7);
}

/* ===== FORMS ===== */
.form-group {
    margin-bottom: 1.75rem;
}

.form-label {
    display: block;
    margin-bottom: 0.75rem;
    font-weight: 600;
    color: var(--text-color);
}

.form-control {
    width: 100%;
    padding: 0.875rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 1rem;
    transition: var(--transition);
    background: white;
}

.form-control:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 4px rgba(139, 92, 246, 0.1);
}

textarea.form-control {
    resize: vertical;
    min-height: 140px;
}

/* ===== TABLES ===== */
.table {
    width: 100%;
    border-collapse: collapse;
    background: white;
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: var(--shadow-md);
}

.table th,
.table td {
    padding: 1.25rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.table th {
    background: linear-gradient(135deg, rgba(139, 92, 246, 0.1), rgba(236, 72, 153, 0.1));
    font-weight: 700;
    color: var(--text-color);
}

.table tr:last-child td {
    border-bottom: none;
}

.table tr:hover {
    background: rgba(139, 92, 246, 0.03);
}

/* ===== LOADING SPINNER ===== */
@keyframes spin {
    to { transform: rotate(360deg); }
}

.spinner {
    width: 48px;
    height: 48px;
    border: 4px solid var(--border-color);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 1024px) {
    .books-layout {
        grid-template-columns: 1fr;
    }
    
    .books-sidebar {
        position: static;
    }
}

@media (max-width: 768px) {
    .mobile-menu-toggle {
        display: block;
    }
    
    .nav-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
        flex-direction: column;
        padding: 1.5rem;
        gap: 1rem;
        box-shadow: var(--shadow-xl);
    }
    
    .nav-menu.active {
        display: flex;
    }
    
    .dropdown-menu {
        position: static;
        box-shadow: none;
        background: rgba(255, 255, 255, 0.15);
        margin-top: 0.5rem;
        transform: none;
    }
    
    .dropdown-menu a {
        color: white;
    }
    
    .hero-title {
        font-size: 2.25rem;
    }
    
    .hero-subtitle {
        font-size: 1.125rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .section-header {
        flex-direction: column;
        gap: 1.5rem;
        text-align: center;
    }
    
    .books-grid {
        grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
        gap: 1.5rem;
    }
    
    .page-header h1 {
        font-size: 2rem;
    }
    
    .filter-section {
        padding: 1.5rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }
    
    section {
        padding: 3rem 0;
    }
    
    .hero {
        padding: 4rem 0;
    }
    
    .hero-title {
        font-size: 1.875rem;
    }
    
    .books-grid {
        grid-template-columns: 1fr;
    }
    
    .book-cover {
        height: 320px;
    }
    
    .categories-grid {
        grid-template-columns: 1fr;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
}

/* ===== UTILITY CLASSES ===== */
.text-center { text-align: center; }
.text-right { text-align: right; }
.text-left { text-align: left; }

.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }
.mt-5 { margin-top: 3rem; }

.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }
.mb-5 { margin-bottom: 3rem; }

.p-0 { padding: 0; }
.p-1 { padding: 0.5rem; }
.p-2 { padding: 1rem; }
.p-3 { padding: 1.5rem; }
.p-4 { padding: 2rem; }
.p-5 { padding: 3rem; }

.d-none { display: none; }
.d-block { display: block; }
.d-flex { display: flex; }
.d-grid { display: grid; }

.flex-column { flex-direction: column; }
.align-center { align-items: center; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }

.w-100 { width: 100%; }
.h-100 { height: 100%; }

.rounded { border-radius: var(--radius-md); }
.rounded-lg { border-radius: var(--radius-lg); }
.rounded-xl { border-radius: var(--radius-xl); }

.shadow { box-shadow: var(--shadow); }
.shadow-md { box-shadow: var(--shadow-md); }
.shadow-lg { box-shadow: var(--shadow-lg); }
.shadow-xl { box-shadow: var(--shadow-xl); }

/* ===== SCROLL ANIMATIONS ===== */
@keyframes fadeInUpScroll {
    from {
        opacity: 0;
        transform: translateY(40px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.animate-on-scroll {
    animation: fadeInUpScroll 0.8s ease forwards;
}

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

/* ===== GLASS MORPHISM ===== */
.glass {
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.3);
}
/**
 * BookStore Premium Stylesheet
 * Modern, animated, world-class UI/UX design
 */

/* ===== ROOT VARIABLES ===== */
:root {
    --primary-color: #8B5CF6;
    --secondary-color: #EC4899;
    --accent-color: #F59E0B;
    --success-color: #10B981;
    --danger-color: #EF4444;
    --warning-color: #F59E0B;
    --info-color: #3B82F6;
    --dark-color: #1F2937;
    --darker-color: #111827;
    --light-color: #F9FAFB;
    --border-color: #E5E7EB;
    --text-color: #1F2937;
    --text-secondary: #6B7280;
    --text-light: #9CA3AF;
    --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
}

/* ===== RESET & BASE ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background: #FFFFFF;
    overflow-x: hidden;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

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

a:hover {
    color: var(--secondary-color);
}

/* ===== CONTAINER ===== */
.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ===== SMOOTH SCROLL ===== */
html {
    scroll-behavior: smooth;
}

/* ===== NAVIGATION ===== */
.navbar {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    padding: 1rem 0;
    box-shadow: var(--shadow-lg);
    position: sticky;
    top: 0;
    z-index: 1000;
    backdrop-filter: blur(10px);
}

.nav-wrapper {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.75rem;
    font-weight: 800;
    color: white;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: var(--transition);
}

.logo:hover {
    transform: scale(1.05);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2.5rem;
    align-items: center;
}

.nav-menu a {
    color: white;
    font-weight: 600;
    font-size: 0.95rem;
    position: relative;
    padding: 0.5rem 0;
}

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 3px;
    background: white;
    border-radius: 2px;
    transition: var(--transition);
}

.nav-menu a:hover::after {
    width: 100%;
}

.cart-link {
    position: relative;
    background: rgba(255, 255, 255, 0.2);
    padding: 0.5rem 1rem;
    border-radius: var(--radius-lg);
    transition: var(--transition);
}

.cart-link:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

.cart-badge {
    position: absolute;
    top: -8px;
    right: -8px;
    background: linear-gradient(135deg, var(--danger-color), #DC2626);
    color: white;
    border-radius: 50%;
    min-width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.75rem;
    font-weight: 700;
    box-shadow: 0 4px 8px rgba(239, 68, 68, 0.4);
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.1); }
}

.mobile-menu-toggle {
    display: none;
    background: rgba(255, 255, 255, 0.2);
    border: none;
    color: white;
    font-size: 1.5rem;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: var(--radius-sm);
    transition: var(--transition);
}

.mobile-menu-toggle:hover {
    background: rgba(255, 255, 255, 0.3);
}

/* Dropdown */
.dropdown {
    position: relative;
}

.dropdown-toggle {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.dropdown-menu {
    display: none;
    position: absolute;
    top: calc(100% + 1rem);
    left: 50%;
    transform: translateX(-50%);
    background: white;
    min-width: 220px;
    box-shadow: var(--shadow-xl);
    border-radius: var(--radius-md);
    padding: 0.75rem;
    list-style: none;
    animation: dropdownSlide 0.3s ease;
}

@keyframes dropdownSlide {
    from {
        opacity: 0;
        transform: translateX(-50%) translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateX(-50%) translateY(0);
    }
}

.dropdown:hover .dropdown-menu {
    display: block;
}

.dropdown-menu li {
    padding: 0;
}

.dropdown-menu a {
    color: var(--text-color);
    padding: 0.75rem 1rem;
    display: block;
    border-radius: var(--radius-sm);
    font-weight: 500;
    transition: var(--transition);
}

.dropdown-menu a:hover {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    transform: translateX(5px);
}

/* ===== BUTTONS ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.875rem 1.75rem;
    border-radius: var(--radius-lg);
    font-weight: 600;
    font-size: 0.95rem;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    text-decoration: none;
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.3);
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.btn:hover::before {
    width: 300px;
    height: 300px;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    box-shadow: 0 4px 12px rgba(139, 92, 246, 0.4);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(139, 92, 246, 0.5);
}

.btn-success {
    background: linear-gradient(135deg, var(--success-color), #059669);
    color: white;
    box-shadow: 0 4px 12px rgba(16, 185, 129, 0.4);
}

.btn-danger {
    background: linear-gradient(135deg, var(--danger-color), #DC2626);
    color: white;
    box-shadow: 0 4px 12px rgba(239, 68, 68, 0.4);
}

.btn-outline {
    background: transparent;
    border: 2px solid var(--primary-color);
    color: var(--primary-color);
    box-shadow: none;
}

.btn-outline:hover {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border-color: transparent;
}

.btn-sm {
    padding: 0.625rem 1.25rem;
    font-size: 0.875rem;
}

.btn-lg {
    padding: 1.125rem 2.25rem;
    font-size: 1.125rem;
    border-radius: var(--radius-xl);
}

.btn-block {
    width: 100%;
}

/* ===== ANIMATED TOOLTIPS ===== */
[data-tooltip] {
    position: relative;
}

[data-tooltip]::after {
    content: attr(data-tooltip);
    position: absolute;
    bottom: calc(100% + 10px);
    left: 50%;
    transform: translateX(-50%) translateY(-5px);
    background: var(--darker-color);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    white-space: nowrap;
    opacity: 0;
    pointer-events: none;
    transition: var(--transition);
    z-index: 1000;
}

[data-tooltip]:hover::after {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
}

/* ===== ALERTS ===== */
.alert {
    padding: 1rem 1.5rem;
    border-radius: var(--radius-md);
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 1rem;
    animation: slideIn 0.3s ease;
}

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

.alert-success {
    background: linear-gradient(135deg, #ECFDF5, #D1FAE5);
    color: #065F46;
    border-left: 4px solid var(--success-color);
}

.alert-error {
    background: linear-gradient(135deg, #FEF2F2, #FEE2E2);
    color: #991B1B;
    border-left: 4px solid var(--danger-color);
}

/* ===== HERO SECTION ===== */
.hero {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    padding: 6rem 0;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.05'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

.hero-content {
    position: relative;
    z-index: 1;
}

.hero-title {
    font-size: 3.5rem;
    margin-bottom: 1.5rem;
    font-weight: 800;
    line-height: 1.2;
    animation: fadeInUp 0.8s ease;
}

.hero-subtitle {
    font-size: 1.375rem;
    margin-bottom: 2.5rem;
    opacity: 0.95;
    font-weight: 400;
    animation: fadeInUp 0.8s ease 0.2s both;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ===== SECTIONS ===== */
section {
    padding: 5rem 0;
}

.section-title {
    font-size: 2.5rem;
    margin-bottom: 3rem;
    text-align: center;
    font-weight: 800;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 3rem;
}

/* ===== CATEGORIES ===== */
.categories-section {
    background: linear-gradient(180deg, #FFFFFF 0%, var(--light-color) 100%);
}

.categories-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 2rem;
}

.category-card {
    background: white;
    padding: 2.5rem 2rem;
    border-radius: var(--radius-xl);
    text-align: center;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    color: var(--text-color);
    position: relative;
    overflow: hidden;
}

.category-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    transform: scaleX(0);
    transition: var(--transition);
}

.category-card:hover::before {
    transform: scaleX(1);
}

.category-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

.category-card i {
    font-size: 3.5rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 1.25rem;
    display: inline-block;
    transition: var(--transition);
}

.category-card:hover i {
    transform: scale(1.1) rotate(5deg);
}

.category-card h3 {
    margin-bottom: 0.75rem;
    color: var(--text-color);
    font-size: 1.25rem;
    font-weight: 700;
}

.category-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* ===== ANIMATED BOOK CARDS ===== */
.books-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 2.5rem;
}

.book-card {
    background: white;
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    position: relative;
    height: 100%;
    display: flex;
    flex-direction: column;
}

.book-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    opacity: 0;
    transition: var(--transition);
    z-index: 1;
}

.book-card:hover::before {
    opacity: 0.05;
}

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

.book-cover {
    position: relative;
    width: 100%;
    height: 380px;
    overflow: hidden;
    background: linear-gradient(135deg, #F3F4F6, #E5E7EB);
}

.book-cover img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition);
}

.book-card:hover .book-cover img {
    transform: scale(1.08);
}

.book-cover-placeholder {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    position: relative;
}

.book-cover-placeholder::before {
    content: '';
    position: absolute;
    width: 150px;
    height: 150px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.2);
    animation: floating 3s infinite ease-in-out;
}

@keyframes floating {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-20px); }
}

.book-cover-placeholder i {
    font-size: 5rem;
    color: rgba(255, 255, 255, 0.6);
    position: relative;
    z-index: 1;
}

.book-badge {
    position: absolute;
    top: 16px;
    right: 16px;
    background: linear-gradient(135deg, var(--success-color), #059669);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: var(--radius-lg);
    font-size: 0.875rem;
    font-weight: 700;
    box-shadow: 0 4px 12px rgba(16, 185, 129, 0.4);
    z-index: 2;
    animation: bounce 2s infinite;
}

@keyframes bounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-5px); }
}

.book-info {
    padding: 1.75rem;
    flex: 1;
    display: flex;
    flex-direction: column;
}

.book-title {
    font-size: 1.25rem;
    margin-bottom: 0.75rem;
    line-height: 1.4;
    font-weight: 700;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.book-title a {
    color: var(--text-color);
    transition: var(--transition);
}

.book-title a:hover {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.book-author {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.book-category {
    color: var(--primary-color);
    font-size: 0.875rem;
    margin-bottom: 1.25rem;
    font-weight: 600;
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background: linear-gradient(135deg, rgba(139, 92, 246, 0.1), rgba(236, 72, 153, 0.1));
    border-radius: var(--radius-sm);
}

.book-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: auto;
    padding-top: 1.25rem;
    border-top: 2px solid var(--border-color);
}

.book-price {
    font-size: 1.5rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* ===== FEATURES ===== */
.features {
    background: linear-gradient(180deg, var(--light-color) 0%, #FFFFFF 100%);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2.5rem;
}

.feature-card {
    background: white;
    padding: 3rem 2rem;
    border-radius: var(--radius-xl);
    text-align: center;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    width: 200px;
    height: 200px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    opacity: 0.05;
    top: -100px;
    right: -100px;
    transition: var(--transition);
}

.feature-card:hover::before {
    transform: scale(1.5);
    opacity: 0.1;
}

.feature-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

.feature-card i {
    font-size: 4rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 1.5rem;
    display: inline-block;
    transition: var(--transition);
}

.feature-card:hover i {
    transform: scale(1.2) rotate(10deg);
}

.feature-card h3 {
    margin-bottom: 1rem;
    font-size: 1.375rem;
    font-weight: 700;
}

.feature-card p {
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ===== BOOKS PAGE LAYOUT ===== */
.page-header {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    padding: 4rem 0;
    text-align: center;
    margin-bottom: 3rem;
}

.page-header h1 {
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: 1rem;
}

.books-layout {
    display: grid;
    grid-template-columns: 280px 1fr;
    gap: 3rem;
}

.books-sidebar {
    position: sticky;
    top: 100px;
    height: fit-content;
}

.filter-section {
    background: white;
    padding: 2rem;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    margin-bottom: 2rem;
}

.filter-section h3 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    color: var(--text-color);
}

.search-form {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.form-input {
    width: 100%;
    padding: 0.875rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 0.95rem;
    transition: var(--transition);
}

.form-input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 4px rgba(139, 92, 246, 0.1);
}

.category-filter {
    list-style: none;
}

.category-filter li {
    margin-bottom: 0.5rem;
}

.category-filter a {
    display: block;
    padding: 0.875rem 1rem;
    color: var(--text-color);
    border-radius: var(--radius-md);
    transition: var(--transition);
    font-weight: 500;
}

.category-filter a:hover,
.category-filter a.active {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    transform: translateX(5px);
}

.search-info {
    padding: 1.5rem;
    background: linear-gradient(135deg, rgba(139, 92, 246, 0.1), rgba(236, 72, 153, 0.1));
    border-radius: var(--radius-md);
    margin-bottom: 2rem;
    border-left: 4px solid var(--primary-color);
}

.no-results {
    text-align: center;
    padding: 5rem 2rem;
    background: white;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
}

.no-results i {
    font-size: 5rem;
    color: var(--text-light);
    margin-bottom: 1.5rem;
}

.no-results h3 {
    font-size: 2rem;
    margin-bottom: 1rem;
    color: var(--text-color);
}

.no-results p {
    color: var(--text-secondary);
    margin-bottom: 2rem;
    font-size: 1.125rem;
}

/* ===== PAGINATION ===== */
.pagination {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 0.75rem;
    margin-top: 4rem;
    flex-wrap: wrap;
}

.pagination-btn,
.pagination-number {
    padding: 0.875rem 1.25rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-color);
    font-weight: 600;
    transition: var(--transition);
    background: white;
}

.pagination-btn:hover,
.pagination-number:hover {
    border-color: var(--primary-color);
    background: linear-gradient(135deg, rgba(139, 92, 246, 0.1), rgba(236, 72, 153, 0.1));
    transform: translateY(-2px);
}

.pagination-number.active {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border-color: transparent;
    box-shadow: 0 4px 12px rgba(139, 92, 246, 0.4);
}

.pagination-numbers {
    display: flex;
    gap: 0.5rem;
}

/* ===== FOOTER ===== */
.footer {
    background: linear-gradient(135deg, #1F2937 0%, #111827 100%);
    color: white;
    padding: 4rem 0 1.5rem;
    margin-top: 5rem;
    position: relative;
}

.footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 3rem;
    margin-bottom: 3rem;
}

.footer-section h3,
.footer-section h4 {
    margin-bottom: 1.5rem;
    font-weight: 700;
    font-size: 1.25rem;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.75rem;
}

.footer-section a {
    color: rgba(255, 255, 255, 0.8);
    transition: var(--transition);
}

.footer-section a:hover {
    color: white;
    padding-left: 5px;
}

.social-links {
    display: flex;
    gap: 1rem;
    margin-top: 1.5rem;
}

.social-links a {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.1);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
    font-size: 1.25rem;
}

.social-links a:hover {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    transform: translateY(-5px);
    box-shadow: 0 8px 16px rgba(139, 92, 246, 0.4);
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.7);
}

/* ===== FORMS ===== */
.form-group {
    margin-bottom: 1.75rem;
}

.form-label {
    display: block;
    margin-bottom: 0.75rem;
    font-weight: 600;
    color: var(--text-color);
}

.form-control {
    width: 100%;
    padding: 0.875rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 1rem;
    transition: var(--transition);
    background: white;
}

.form-control:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 4px rgba(139, 92, 246, 0.1);
}

textarea.form-control {
    resize: vertical;
    min-height: 140px;
}

/* ===== TABLES ===== */
.table {
    width: 100%;
    border-collapse: collapse;
    background: white;
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: var(--shadow-md);
}

.table th,
.table td {
    padding: 1.25rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.table th {
    background: linear-gradient(135deg, rgba(139, 92, 246, 0.1), rgba(236, 72, 153, 0.1));
    font-weight: 700;
    color: var(--text-color);
}

.table tr:last-child td {
    border-bottom: none;
}

.table tr:hover {
    background: rgba(139, 92, 246, 0.03);
}

/* ===== LOADING SPINNER ===== */
@keyframes spin {
    to { transform: rotate(360deg); }
}

.spinner {
    width: 48px;
    height: 48px;
    border: 4px solid var(--border-color);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 1024px) {
    .books-layout {
        grid-template-columns: 1fr;
    }
    
    .books-sidebar {
        position: static;
    }
}

@media (max-width: 768px) {
    .mobile-menu-toggle {
        display: block;
    }
    
    .nav-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
        flex-direction: column;
        padding: 1.5rem;
        gap: 1rem;
        box-shadow: var(--shadow-xl);
    }
    
    .nav-menu.active {
        display: flex;
    }
    
    .dropdown-menu {
        position: static;
        box-shadow: none;
        background: rgba(255, 255, 255, 0.15);
        margin-top: 0.5rem;
        transform: none;
    }
    
    .dropdown-menu a {
        color: white;
    }
    
    .hero-title {
        font-size: 2.25rem;
    }
    
    .hero-subtitle {
        font-size: 1.125rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .section-header {
        flex-direction: column;
        gap: 1.5rem;
        text-align: center;
    }
    
    .books-grid {
        grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
        gap: 1.5rem;
    }
    
    .page-header h1 {
        font-size: 2rem;
    }
    
    .filter-section {
        padding: 1.5rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }
    
    section {
        padding: 3rem 0;
    }
    
    .hero {
        padding: 4rem 0;
    }
    
    .hero-title {
        font-size: 1.875rem;
    }
    
    .books-grid {
        grid-template-columns: 1fr;
    }
    
    .book-cover {
        height: 320px;
    }
    
    .categories-grid {
        grid-template-columns: 1fr;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
}

/* ===== UTILITY CLASSES ===== */
.text-center { text-align: center; }
.text-right { text-align: right; }
.text-left { text-align: left; }

.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }
.mt-5 { margin-top: 3rem; }

.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }
.mb-5 { margin-bottom: 3rem; }

.p-0 { padding: 0; }
.p-1 { padding: 0.5rem; }
.p-2 { padding: 1rem; }
.p-3 { padding: 1.5rem; }
.p-4 { padding: 2rem; }
.p-5 { padding: 3rem; }

.d-none { display: none; }
.d-block { display: block; }
.d-flex { display: flex; }
.d-grid { display: grid; }

.flex-column { flex-direction: column; }
.align-center { align-items: center; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }

.w-100 { width: 100%; }
.h-100 { height: 100%; }

.rounded { border-radius: var(--radius-md); }
.rounded-lg { border-radius: var(--radius-lg); }
.rounded-xl { border-radius: var(--radius-xl); }

.shadow { box-shadow: var(--shadow); }
.shadow-md { box-shadow: var(--shadow-md); }
.shadow-lg { box-shadow: var(--shadow-lg); }
.shadow-xl { box-shadow: var(--shadow-xl); }

/* ===== SCROLL ANIMATIONS ===== */
@keyframes fadeInUpScroll {
    from {
        opacity: 0;
        transform: translateY(40px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.animate-on-scroll {
    animation: fadeInUpScroll 0.8s ease forwards;
}

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

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

/* ===== BOOK DETAIL PAGE ===== */
.book-detail-section {
    padding: 4rem 0;
}

.book-detail-layout {
    display: grid;
    grid-template-columns: 400px 1fr;
    gap: 4rem;
    background: white;
    padding: 3rem;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
}

.book-detail-cover {
    position: sticky;
    top: 120px;
    height: fit-content;
}

.detail-cover-image {
    width: 100%;
    height: auto;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
    transition: var(--transition);
}

.detail-cover-image:hover {
    transform: scale(1.02);
}

.detail-cover-placeholder {
    width: 100%;
    height: 550px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: var(--radius-lg);
}

.detail-cover-placeholder i {
    font-size: 8rem;
    color: rgba(255, 255, 255, 0.6);
}

.detail-badge {
    margin-top: 1.5rem;
    padding: 1rem;
    background: linear-gradient(135deg, var(--success-color), #059669);
    color: white;
    border-radius: var(--radius-md);
    text-align: center;
    font-weight: 700;
    box-shadow: 0 4px 12px rgba(16, 185, 129, 0.4);
}

.category-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: linear-gradient(135deg, rgba(139, 92, 246, 0.1), rgba(236, 72, 153, 0.1));
    color: var(--primary-color);
    border-radius: var(--radius-lg);
    font-weight: 600;
    font-size: 0.95rem;
    margin-bottom: 1.5rem;
    transition: var(--transition);
}

.category-badge:hover {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
}

.book-detail-title {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 1rem;
    line-height: 1.3;
    color: var(--text-color);
}

.book-detail-author {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.book-meta-info {
    display: flex;
    flex-wrap: wrap;
    gap: 2rem;
    margin-bottom: 2rem;
    padding: 1.5rem;
    background: var(--light-color);
    border-radius: var(--radius-md);
}

.meta-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.meta-item i {
    color: var(--primary-color);
    font-size: 1.125rem;
}

.book-price-section {
    margin: 2rem 0;
    padding: 2rem;
    background: linear-gradient(135deg, rgba(139, 92, 246, 0.05), rgba(236, 72, 153, 0.05));
    border-radius: var(--radius-lg);
    border-left: 4px solid var(--primary-color);
}

.current-price {
    font-size: 3rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.free-price {
    font-size: 3rem;
    font-weight: 800;
    color: var(--success-color);
}

.book-actions {
    display: flex;
    gap: 1rem;
    margin-bottom: 3rem;
}

.book-description {
    padding-top: 2rem;
    border-top: 2px solid var(--border-color);
}

.book-description h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.description-content {
    color: var(--text-secondary);
    line-height: 1.8;
    font-size: 1.05rem;
}

.related-books-section {
    background: var(--light-color);
}

@media (max-width: 1024px) {
    .book-detail-layout {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .book-detail-cover {
        position: static;
    }
    
    .detail-cover-image {
        max-width: 400px;
        margin: 0 auto;
        display: block;
    }
}

@media (max-width: 768px) {
    .book-detail-title {
        font-size: 2rem;
    }
    
    .current-price,
    .free-price {
        font-size: 2.25rem;
    }
    
    .book-actions {
        flex-direction: column;
    }
    
    .book-meta-info {
        flex-direction: column;
        gap: 1rem;
    }
}