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

:root {
    --primary-color: #2563eb;
    --primary-dark: #1d4ed8;
    --secondary-color: #64748b;
    --danger-color: #dc2626;
    --success-color: #16a34a;
    --bg-color: #f8fafc;
    --surface-color: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.15);
    
    /* Touch-friendly sizes */
    --tap-target-min: 48px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

#app {
    max-width: 100%;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header */
.app-header {
    background: var(--primary-color);
    color: white;
    padding: var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

.app-header h1 {
    font-size: 1.5rem;
    font-weight: 700;
}

/* Buttons */
.btn {
    border: none;
    border-radius: 8px;
    padding: 12px 20px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    min-height: var(--tap-target-min);
    touch-action: manipulation;
    -webkit-tap-highlight-color: transparent;
}

.btn:active {
    transform: scale(0.97);
}

.btn-primary {
    background: var(--primary-color);
    color: white;
}

.btn-primary:active {
    background: var(--primary-dark);
}

.btn-secondary {
    background: var(--secondary-color);
    color: white;
}

.btn-danger {
    background: var(--danger-color);
    color: white;
}

.btn-large {
    width: 100%;
    padding: 16px;
    font-size: 1.1rem;
    margin-bottom: var(--spacing-md);
}

.icon-btn {
    background: transparent;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    padding: 8px;
    min-width: var(--tap-target-min);
    min-height: var(--tap-target-min);
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 8px;
    transition: background 0.2s;
}

.icon-btn:active {
    background: rgba(255, 255, 255, 0.2);
}

/* Views */
main {
    flex: 1;
    padding: var(--spacing-md);
    position: relative;
}

.view {
    display: none;
    animation: fadeIn 0.3s;
}

.view.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.view-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--spacing-lg);
    gap: var(--spacing-md);
}

.view-header h2 {
    font-size: 1.5rem;
    font-weight: 700;
    flex: 1;
}

/* Collections Grid */
.collections-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    gap: var(--spacing-md);
}

.collection-card {
    background: var(--surface-color);
    border-radius: 12px;
    padding: var(--spacing-lg);
    box-shadow: var(--shadow);
    cursor: pointer;
    transition: all 0.2s;
    min-height: 120px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
}

.collection-card:active {
    transform: scale(0.97);
    box-shadow: var(--shadow-lg);
}

.collection-card h3 {
    font-size: 1.1rem;
    margin-bottom: var(--spacing-sm);
    word-break: break-word;
}

.collection-card p {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* Action Buttons */
.action-buttons {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.action-buttons .btn {
    flex: 1;
}

/* Export Buttons */
.export-buttons {
    margin-bottom: var(--spacing-lg);
}

.export-all-section {
    margin-top: var(--spacing-lg);
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--border-color);
}

.btn-small {
    padding: 10px 16px;
    font-size: 0.95rem;
}

/* Books List */
.books-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.book-card {
    background: var(--surface-color);
    border-radius: 12px;
    padding: var(--spacing-md);
    box-shadow: var(--shadow);
    display: flex;
    gap: var(--spacing-md);
}

.book-cover {
    width: 60px;
    height: 90px;
    object-fit: cover;
    border-radius: 4px;
    background: var(--border-color);
    flex-shrink: 0;
}

.book-info {
    flex: 1;
    min-width: 0;
}

.book-info h3 {
    font-size: 1rem;
    margin-bottom: 4px;
    overflow: hidden;
    text-overflow: ellipsis;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
}

.book-info p {
    color: var(--text-secondary);
    font-size: 0.85rem;
    margin-bottom: 2px;
}

.book-actions {
    display: flex;
    align-items: center;
}

.book-actions button {
    background: transparent;
    border: none;
    font-size: 1.3rem;
    cursor: pointer;
    padding: 8px;
    min-width: var(--tap-target-min);
    min-height: var(--tap-target-min);
    color: var(--danger-color);
}

/* Scanner */
#scanner-container {
    margin: var(--spacing-lg) 0;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow-lg);
}

#reader {
    border: none;
}

.scanner-status {
    padding: var(--spacing-md);
    background: var(--surface-color);
    border-radius: 8px;
    text-align: center;
    font-size: 0.95rem;
    color: var(--text-secondary);
}

/* Modals */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 1000;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-md);
}

.modal.active {
    display: flex;
    animation: fadeIn 0.2s;
}

.modal-content {
    background: var(--surface-color);
    border-radius: 16px;
    padding: var(--spacing-lg);
    max-width: 400px;
    width: 100%;
    box-shadow: var(--shadow-lg);
    animation: slideUp 0.3s;
}

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

.modal-content h3 {
    margin-bottom: var(--spacing-lg);
    font-size: 1.3rem;
}

.input-text {
    width: 100%;
    padding: 12px 16px;
    font-size: 1rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    margin-bottom: var(--spacing-md);
    transition: border-color 0.2s;
}

.input-text:focus {
    outline: none;
    border-color: var(--primary-color);
}

.modal-actions {
    display: flex;
    gap: var(--spacing-md);
    margin-top: var(--spacing-lg);
}

.modal-actions .btn {
    flex: 1;
}

/* Loading Overlay */
.loading-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.7);
    z-index: 2000;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    color: white;
}

.loading-overlay.active {
    display: flex;
}

.spinner {
    width: 50px;
    height: 50px;
    border: 4px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.loading-overlay p {
    margin-top: var(--spacing-md);
    font-size: 1.1rem;
}

/* Toast Notifications */
.toast {
    position: fixed;
    bottom: var(--spacing-lg);
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--text-primary);
    color: white;
    padding: 12px 24px;
    border-radius: 8px;
    box-shadow: var(--shadow-lg);
    z-index: 3000;
    transition: transform 0.3s;
    max-width: calc(100% - 32px);
}

.toast.active {
    transform: translateX(-50%) translateY(0);
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: var(--spacing-lg) var(--spacing-md);
    color: var(--text-secondary);
}

.empty-state h3 {
    font-size: 1.2rem;
    margin-bottom: var(--spacing-sm);
}

/* Responsive adjustments */
@media (min-width: 768px) {
    #app {
        max-width: 768px;
        margin: 0 auto;
        box-shadow: var(--shadow-lg);
    }
    
    .collections-grid {
        grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    }
}

/* Prevent text selection on interactive elements */
.btn, .icon-btn, .collection-card, .book-card {
    -webkit-user-select: none;
    user-select: none;
}