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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
}

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

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 40px;
    background: white;
    padding: 30px;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

h1 {
    color: #333;
    font-size: 2.5rem;
}

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

.btn-primary {
    background: #667eea;
    color: white;
}

.btn-primary:hover {
    background: #5568d3;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
}

.btn-secondary {
    background: #e0e0e0;
    color: #333;
}

.btn-secondary:hover {
    background: #d0d0d0;
}

.btn-danger {
    background: #f44336;
    color: white;
    padding: 8px 16px;
    font-size: 0.9rem;
}

.btn-danger:hover {
    background: #d32f2f;
}

.btn-toggle {
    background: #4caf50;
    color: white;
    padding: 8px 16px;
    font-size: 0.9rem;
}

.btn-toggle:hover {
    background: #45a049;
}

.btn-toggle.unread {
    background: #ff9800;
}

.btn-toggle.unread:hover {
    background: #f57c00;
}

/* Library Grid */
.library-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 25px;
}

/* Book Card */
.book-card {
    background: white;
    border-radius: 12px;
    padding: 25px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border-left: 5px solid #667eea;
}

.book-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.15);
}

.book-card.read {
    border-left-color: #4caf50;
}

.book-card h3 {
    color: #333;
    margin-bottom: 10px;
    font-size: 1.3rem;
}

.book-card .author {
    color: #666;
    font-style: italic;
    margin-bottom: 8px;
}

.book-card .pages {
    color: #888;
    font-size: 0.9rem;
    margin-bottom: 15px;
}

.book-card .status {
    display: inline-block;
    padding: 5px 12px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 15px;
}

.book-card .status.read {
    background: #e8f5e9;
    color: #4caf50;
}

.book-card .status.unread {
    background: #fff3e0;
    color: #ff9800;
}

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

/* Dialog */
dialog {
    border: none;
    border-radius: 15px;
    padding: 0;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    max-width: 500px;
    width: 90%;
}

dialog::backdrop {
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(3px);
}

.dialog-content {
    padding: 30px;
}

.dialog-content h2 {
    color: #333;
    margin-bottom: 25px;
}

/* Form */
.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    color: #333;
    font-weight: 600;
    margin-bottom: 8px;
}

.form-group input[type="text"],
.form-group input[type="number"] {
    width: 100%;
    padding: 12px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

.form-group input[type="text"]:focus,
.form-group input[type="number"]:focus {
    outline: none;
    border-color: #667eea;
}

.checkbox-group label {
    display: flex;
    align-items: center;
    gap: 10px;
    cursor: pointer;
}

.checkbox-group input[type="checkbox"] {
    width: 20px;
    height: 20px;
    cursor: pointer;
}

.form-actions {
    display: flex;
    gap: 10px;
    margin-top: 25px;
}

.form-actions button {
    flex: 1;
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: 60px 20px;
    background: white;
    border-radius: 15px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.empty-state h2 {
    color: #333;
    margin-bottom: 15px;
}

.empty-state p {
    color: #666;
    font-size: 1.1rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    header {
        flex-direction: column;
        gap: 20px;
        text-align: center;
    }

    h1 {
        font-size: 2rem;
    }

    .library-grid {
        grid-template-columns: 1fr;
    }
}