/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f8fafc;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Navigation */
.navbar {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.nav-logo h2 a {
    color: #2563eb;
    text-decoration: none;
    font-weight: 700;
    font-size: 1.5rem;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-link {
    color: #64748b;
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
}

.nav-link:hover,
.nav-link.active {
    color: #2563eb;
}

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
}

.bar {
    width: 25px;
    height: 3px;
    background-color: #333;
    margin: 3px 0;
    transition: 0.3s;
}

/* Hero Section */
.bookstore-hero {
    background: linear-gradient(rgba(0, 0, 0, 0.6), rgba(0, 0, 0, 0.6)), url('bookstore-background.jpg');
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
    min-height: 70vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    color: white;
    margin-top: 70px;
}

.page-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.5);
}

.page-subtitle {
    font-size: 1.25rem;
    max-width: 600px;
    margin: 0 auto 2rem;
    opacity: 0.9;
    line-height: 1.6;
}

.bookstore-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 12px 24px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

.btn-primary {
    background: #2563eb;
    color: white;
}

.btn-primary:hover {
    background: #1d4ed8;
    transform: translateY(-2px);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    border: 2px solid rgba(255, 255, 255, 0.3);
}

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

/* Search Section */
.search-section {
    padding: 3rem 0;
    background: white;
}

.search-bar {
    display: flex;
    max-width: 600px;
    margin: 0 auto;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.search-bar input {
    flex: 1;
    padding: 16px 20px;
    border: none;
    font-size: 1rem;
    outline: none;
}

.search-bar button {
    background: #10b981;
    color: white;
    border: none;
    padding: 16px 20px;
    cursor: pointer;
    transition: background 0.3s ease;
}

.search-bar button:hover {
    background: #059669;
}

/* Books Section */
.books-section {
    padding: 4rem 0;
    background: #f8fafc;
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    color: #1e293b;
}

.view-toggle {
    display: flex;
    gap: 0.5rem;
}

.view-btn {
    background: white;
    border: 2px solid #e2e8f0;
    padding: 8px 12px;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.view-btn.active,
.view-btn:hover {
    background: #2563eb;
    color: white;
    border-color: #2563eb;
}

/* Loading Spinner */
.loading-spinner {
    text-align: center;
    padding: 4rem 0;
}

.loading-spinner i {
    font-size: 2rem;
    color: #2563eb;
    margin-bottom: 1rem;
}

/* No Books Message */
.no-books {
    text-align: center;
    padding: 4rem 0;
}

.no-books i {
    font-size: 4rem;
    color: #2563eb;
    margin-bottom: 1rem;
}

.no-books h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: #64748b;
}

.no-books p {
    color: #94a3b8;
    margin-bottom: 2rem;
}

/* Books Grid */
.books-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2rem;
}

.book-card {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    cursor: pointer;
}

.book-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

.book-cover {
    height: 200px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.2rem;
    font-weight: 600;
}

.book-info {
    padding: 1.5rem;
}

.book-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: #1e293b;
}

.book-author {
    color: #64748b;
    margin-bottom: 0.5rem;
}

.book-description {
    color: #94a3b8;
    font-size: 0.9rem;
    line-height: 1.5;
    margin-bottom: 1rem;
}

.book-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.8rem;
    color: #94a3b8;
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    z-index: 2000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
}

.modal-content {
    background-color: white;
    margin: 5% auto;
    padding: 2rem;
    border-radius: 12px;
    width: 90%;
    max-width: 600px;
    position: relative;
    max-height: 80vh;
    overflow-y: auto;
}

.close {
    position: absolute;
    right: 1rem;
    top: 1rem;
    font-size: 1.5rem;
    cursor: pointer;
    color: #94a3b8;
}

.close:hover {
    color: #64748b;
}

/* Login Form */
.login-form h3 {
    margin-bottom: 1.5rem;
    color: #1e293b;
    text-align: center;
}

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

.form-group input {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid #e2e8f0;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

.form-group input:focus {
    outline: none;
    border-color: #2563eb;
}

.auth-switch {
    text-align: center;
    margin-top: 1rem;
    color: #64748b;
}

.auth-switch a {
    color: #2563eb;
    text-decoration: none;
}

/* Footer */
.footer {
    background: #1e293b;
    color: white;
    padding: 3rem 0 1rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3,
.footer-section h4 {
    margin-bottom: 1rem;
    color: #f1f5f9;
}

.footer-section p,
.footer-section li {
    color: #94a3b8;
    line-height: 1.6;
}

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

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section a {
    color: #94a3b8;
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-section a:hover {
    color: #f1f5f9;
}

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

.social-links a {
    display: inline-block;
    width: 40px;
    height: 40px;
    background: #334155;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background 0.3s ease;
}

.social-links a:hover {
    background: #2563eb;
}

.footer-bottom {
    border-top: 1px solid #334155;
    padding-top: 1rem;
    text-align: center;
    color: #94a3b8;
}

/* Utility Classes */
.hidden {
    display: none !important;
}

/* Responsive Design */
@media (max-width: 768px) {
    .hamburger {
        display: flex;
    }
    
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: white;
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: 0 10px 27px rgba(0, 0, 0, 0.05);
        padding: 2rem 0;
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .page-title {
        font-size: 2.5rem;
    }
    
    .page-subtitle {
        font-size: 1.1rem;
    }
    
    .section-header {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .books-grid {
        grid-template-columns: 1fr;
    }
    
    .bookstore-hero {
        background-attachment: scroll;
        min-height: 60vh;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }
    
    .page-title {
        font-size: 2rem;
    }
    
    .bookstore-actions {
        flex-direction: column;
        align-items: center;
    }
    
    .search-bar {
        flex-direction: column;
    }
    
    .search-bar input,
    .search-bar button {
        border-radius: 0;
    }
    
    .search-bar input {
        border-radius: 12px 12px 0 0;
    }
    
    .search-bar button {
        border-radius: 0 0 12px 12px;
    }
}