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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f5f5f5;
    color: #333;
}

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

/* Шапка */
header {
    background-color: #2c3e50;
    color: white;
    padding: 15px 0;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 24px;
    font-weight: bold;
}

nav {
    display: flex;
    align-items: center;
    gap: 20px;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 15px;
}

.nav-links a {
    color: white;
    text-decoration: none;
    padding: 8px 15px;
    border-radius: 4px;
    transition: background-color 0.3s;
}

.nav-links a:hover {
    background-color: #34495e;
}

#userInfo, #adminInfo {
    color: #ecf0f1;
    padding: 8px 15px;
    background-color: #34495e;
    border-radius: 4px;
}

/* Кнопки */
.btn {
    padding: 10px 20px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 14px;
    transition: background-color 0.3s;
}

.btn-primary {
    background-color: #3498db;
    color: white;
}

.btn-primary:hover {
    background-color: #2980b9;
}

.btn-secondary {
    background-color: #95a5a6;
    color: white;
}

.btn-secondary:hover {
    background-color: #7f8c8d;
}

.btn-success {
    background-color: #27ae60;
    color: white;
}

.btn-success:hover {
    background-color: #229954;
}

.btn-danger {
    background-color: #e74c3c;
    color: white;
}

.btn-danger:hover {
    background-color: #c0392b;
}

/* Форма входа */
.login-form {
    max-width: 400px;
    margin: 100px auto;
    padding: 30px;
    background: white;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.login-form h2 {
    margin-bottom: 20px;
    text-align: center;
}

.form-group {
    margin-bottom: 15px;
}

.form-group label {
    display: block;
    margin-bottom: 5px;
    font-weight: 500;
}

.form-group input,
.form-group select {
    width: 100%;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 14px;
}

.login-info {
    margin-top: 20px;
    padding: 15px;
    background-color: #f8f9fa;
    border-radius: 4px;
    font-size: 12px;
    color: #666;
}

.error-message {
    color: #e74c3c;
    margin-top: 10px;
    text-align: center;
}

/* Фильтры */
.filters {
    background: white;
    padding: 20px;
    border-radius: 8px;
    margin-bottom: 30px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.filter-group {
    display: flex;
    align-items: center;
    gap: 10px;
}

.filter-group label {
    font-weight: 500;
}

.filter-group select {
    padding: 8px 15px;
    border: 1px solid #ddd;
    border-radius: 4px;
}

/* Сетка книг */
.book-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.book-card {
    background: white;
    border-radius: 8px;
    padding: 20px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    transition: transform 0.3s;
}

.book-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.2);
}

.book-card h3 {
    font-size: 18px;
    margin-bottom: 10px;
    color: #2c3e50;
}

.book-card .author {
    color: #7f8c8d;
    margin-bottom: 5px;
}

.book-card .category {
    display: inline-block;
    background: #ecf0f1;
    padding: 2px 10px;
    border-radius: 12px;
    font-size: 12px;
    margin-bottom: 10px;
}

.book-card .year {
    color: #95a5a6;
    margin-bottom: 10px;
}

.book-card .price {
    font-size: 20px;
    font-weight: bold;
    color: #2c3e50;
    margin-bottom: 10px;
}

.book-card .status {
    display: inline-block;
    padding: 3px 10px;
    border-radius: 12px;
    font-size: 12px;
    margin-bottom: 10px;
}

.status-available {
    background: #d5f5e3;
    color: #27ae60;
}

.status-rented {
    background: #fdebd0;
    color: #e67e22;
}

.status-unavailable {
    background: #fadbd8;
    color: #e74c3c;
}

.book-card .actions {
    display: flex;
    gap: 10px;
    margin-top: 15px;
    flex-wrap: wrap;
}

.book-card .actions .btn {
    flex: 1;
    font-size: 12px;
    padding: 8px;
}

.book-card .favorite-btn {
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    transition: transform 0.3s;
}

.book-card .favorite-btn:hover {
    transform: scale(1.2);
}

/* Модальные окна */
.modal {
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0,0,0,0.5);
    display: flex;
    justify-content: center;
    align-items: center;
}

.modal-content {
    background: white;
    padding: 30px;
    border-radius: 8px;
    max-width: 500px;
    width: 90%;
    max-height: 80vh;
    overflow-y: auto;
    position: relative;
}

.close {
    position: absolute;
    right: 20px;
    top: 15px;
    font-size: 28px;
    cursor: pointer;
    color: #95a5a6;
}

.close:hover {
    color: #2c3e50;
}

/* Админ панель */
.admin-panel {
    background: white;
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.admin-form {
    background: #f8f9fa;
    padding: 20px;
    border-radius: 8px;
    margin-bottom: 30px;
}

.admin-form h2 {
    margin-bottom: 20px;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
}

.admin-book-item {
    display: grid;
    grid-template-columns: 1fr auto auto;
    gap: 10px;
    padding: 15px;
    border-bottom: 1px solid #ecf0f1;
    align-items: center;
}

.admin-book-item .book-info {
    display: flex;
    flex-direction: column;
}

.admin-book-item .book-title {
    font-weight: 500;
}

.admin-book-item .book-details {
    font-size: 14px;
    color: #7f8c8d;
}

.admin-book-item .actions {
    display: flex;
    gap: 10px;
}

/* Адаптивность */
@media (max-width: 768px) {
    .book-grid {
        grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .nav-links {
        flex-wrap: wrap;
    }
    
    .admin-book-item {
        grid-template-columns: 1fr;
        gap: 10px;
    }
}

/* Стили для пользователей в админке */
.user-card {
    transition: transform 0.3s;
}

.user-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(0,0,0,0.15);
}

.user-card .btn-secondary {
    font-size: 12px;
    padding: 6px 12px;
}

/* Активные вкладки */
.nav-links a.active {
    background-color: #34495e !important;
    border-radius: 4px;
    padding: 8px 15px;
}

/* Адаптивность для карточек пользователей */
@media (max-width: 768px) {
    .user-card > div:first-child {
        flex-direction: column;
        align-items: flex-start !important;
        gap: 10px;
    }
    
    .user-card .btn-secondary {
        width: 100%;
        text-align: center;
    }
}