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

body {
    font-family: 'Inter', sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #fff;
}

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

/* Header Styles */
.header {
    background: linear-gradient(135deg, #ff6b35, #f7931e);
    padding: 1rem 0;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

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

.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-link {
    color: white;
    text-decoration: none;
    font-weight: 600;
    font-size: 1rem;
    transition: all 0.3s ease;
    padding: 0.5rem 1rem;
    border-radius: 6px;
}

.nav-link:hover {
    background-color: rgba(255,255,255,0.2);
    transform: translateY(-2px);
}

.order-btn {
    background-color: #2c3e50;
    color: white;
    text-decoration: none;
    padding: 0.75rem 1.5rem;
    border-radius: 25px;
    font-weight: 600;
    font-size: 0.9rem;
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.order-btn:hover {
    background-color: #34495e;
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
}

/* Banner Styles */
.banner {
    background: linear-gradient(135deg, #3498db, #2980b9);
    color: white;
    text-align: center;
    padding: 4rem 0;
    position: relative;
    overflow: hidden;
}

.banner::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    /* bottom: 0;   background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grain" width="100" height="100" patternUnits="userSpaceOnUse"><circle cx="25" cy="25" r="1" fill="white" opacity="0.1"/><circle cx="75" cy="75" r="1" fill="white" opacity="0.1"/><circle cx="50" cy="10" r="0.5" fill="white" opacity="0.1"/></pattern></defs><rect width="100" height="100" fill="url(%23grain)"/></svg>'); */
    opacity: 0.3;
}

.banner-content {
    position: relative;
    z-index: 2;
}

.banner-content picture {
    display: block;
}

.banner-image {
    width: 100%;
    height: auto;
    display: block;
}

.banner-title {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 1rem;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

.banner-subtitle {
    font-size: 1.2rem;
    font-weight: 400;
    opacity: 0.9;
    max-width: 600px;
    margin: 0 auto;
}

/* Password Section Styles */
.password-section {
    padding: 4rem 0;
    /* background-color: #f8f9fa; */
    background-color: #fff;
}

.password-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: center;
}

.password-image {
    text-align: center;
}

.book-image {
    width: 100%;
    max-width: 800px;
    height: auto;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    transition: transform 0.3s ease;
}

.book-image:hover {
    transform: scale(1.05);
}

.password-form h2 {
    font-size: 1.8rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: #2c3e50;
    line-height: 1.4;
}

.password-form p {
    font-size: 1.1rem;
    color: #666;
    margin-bottom: 2rem;
    line-height: 1.6;
}

.password-input-group {
    background: white;
    padding: 2rem;
    border-radius: 15px;
    box-shadow: 0 5px 20px rgba(0,0,0,0.1);
    border: 2px solid #e74c3c;
}

.password-input-group label {
    display: block;
    font-weight: 600;
    color: #2c3e50;
    margin-bottom: 0.5rem;
    font-size: 1.1rem;
}

.password-input {
    width: 100%;
    padding: 1rem;
    border: 2px solid #ddd;
    border-radius: 8px;
    font-size: 1rem;
    margin-bottom: 1rem;
    transition: border-color 0.3s ease;
}

.password-input:focus {
    outline: none;
    border-color: #e74c3c;
    box-shadow: 0 0 0 3px rgba(231, 76, 60, 0.1);
}

.confirm-btn {
    background-color: #2c3e50;
    color: white;
    border: none;
    padding: 1rem 2rem;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    width: 100%;
}

.confirm-btn:hover {
    background-color: #34495e;
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
}

.confirm-btn:disabled {
    background-color: #95a5a6;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

/* Session Info Styles */
.session-info {
    margin-top: 1rem;
    padding-top: 1rem;
    border-top: 1px solid #eee;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.session-info small {
    color: #666;
    font-size: 0.9rem;
}

.session-info small:first-child {
    color: #3498db;
    font-weight: 500;
}

#lockStatus {
    color: #e74c3c;
    font-weight: 600;
}

/* Loading Spinner */
.loading-spinner {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0,0,0,0.8);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    z-index: 3000;
}

.spinner {
    width: 50px;
    height: 50px;
    border: 4px solid #f3f3f3;
    border-top: 4px solid #3498db;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 1rem;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.loading-spinner p {
    color: white;
    font-size: 1.1rem;
    font-weight: 500;
}

/* Related Books Section */
.related-books {
    background-image: url('../static/images/bgfooter.png');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    background-attachment: fixed;
    padding: 4rem 0;
    color: white;
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 3rem;
    color: white;
}

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

.book-card {
    /* background: white; */
    border-radius: 15px;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(2, 128, 107, 0.2);
    transition: all 0.3s ease;
    color: #028157;
}

.book-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 10px 20px rgba(0,0,0,0.3);
}

.book-card .book-image {
    width: 100%;
    /* height: 200px; */
    overflow: hidden;
}

.book-card .book-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s ease;
}

.book-card:hover .book-image img {
    transform: scale(1.01);
}

.book-title {
    padding: 1.5rem 1.5rem 0.5rem;
    font-size: 1.2rem;
    font-weight: 600;
    color: #3498db;
}

.book-description {
    padding: 0 1.5rem 1.5rem;
    color: #666;
    font-size: 0.95rem;
    line-height: 1.5;
}

.cta-section {
    text-align: center;
}

.cta-button {
    display: inline-block;
    background-color: #3498db;
    color: white;
    text-decoration: none;
    padding: 1rem 2.5rem;
    border-radius: 25px;
    font-weight: 600;
    font-size: 1.1rem;
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.cta-button:hover {
    background-color: #2980b9;
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.3);
}

/* Modal Styles */
.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(5px);
}

.modal-content {
    background-color: white;
    margin: 5% auto;
    padding: 2rem;
    border-radius: 20px;
    width: 90%;
    max-width: 800px;
    text-align: center;
    position: relative;
    animation: modalSlideIn 0.3s ease;
}

@keyframes modalSlideIn {
    from {
        opacity: 0;
        transform: translateY(-50px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.close {
    color: #aaa;
    float: right;
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
    position: absolute;
    top: 1rem;
    right: 1.5rem;
    transition: color 0.3s ease;
}

.close:hover {
    color: #333;
}

.success-content {
    padding: 2rem 0;
}

.success-icon {
    font-size: 4rem;
    color: #27ae60;
    margin-bottom: 1rem;
}

.success-title {
    font-size: 2rem;
    font-weight: 700;
    color: #27ae60;
    margin-bottom: 1rem;
}

.success-message {
    font-size: 1.1rem;
    color: #666;
    line-height: 1.6;
    margin-bottom: 2rem;
}

.error-content {
    padding: 2rem 0;
}

.error-icon {
    font-size: 4rem;
    color: #e74c3c;
    margin-bottom: 1rem;
}

.error-title {
    font-size: 2rem;
    font-weight: 700;
    color: #e74c3c;
    margin-bottom: 1rem;
}

.error-message {
    font-size: 1.1rem;
    color: #666;
    line-height: 1.6;
    margin-bottom: 2rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 0 12px;
    }

    .banner-content {
        border-radius: 12px;
        overflow: hidden;
    }

    .nav {
        flex-direction: column;
        gap: 1rem;
    }
    
    .nav-links {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
    
    .banner-title {
        font-size: 2rem;
    }
    
    .banner-subtitle {
        font-size: 1rem;
    }
    
    .password-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .books-grid {
        grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
        gap: 1.5rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .modal-content {
        margin: 20% auto;
        width: 95%;
        padding: 1.5rem;
    }
    
    .session-info {
        flex-direction: column;
        gap: 0.5rem;
        align-items: flex-start;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 10px;
    }
    
    .banner {
        padding: 2rem 0;
    }
    
    .banner-title {
        font-size: 1.5rem;
    }
    
    .password-section {
        padding: 2rem 0;
    }
    
    .related-books {
        padding: 2rem 0;
    }
    
    .books-grid {
        grid-template-columns: 1fr;
    }
}