/* ===========================
   CSS Variables & Theme Colors
   =========================== */
:root {
    /* Colors */
    --primary-color: #2563eb;
    --primary-dark: #1e40af;
    --primary-light: #60a5fa;

    --secondary-color: #64748b;
    --secondary-dark: #475569;

    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;

    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #e2e8f0;

    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-muted: #94a3b8;

    --border-color: #cbd5e1;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);

    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;

    /* Typography */
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-mono: 'Courier New', Courier, monospace;

    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-normal: 250ms ease-in-out;
    --transition-slow: 350ms ease-in-out;

    /* Border Radius */
    --radius-sm: 0.25rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
}

/* ===========================
   Base Styles
   =========================== */
body {
    font-family: var(--font-sans);
    color: var(--text-primary);
    background-color: var(--bg-secondary);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* ===========================
   Skip Link (Accessibility)
   =========================== */
.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--primary-color);
    color: white;
    padding: var(--spacing-sm) var(--spacing-md);
    z-index: 100;
    border-radius: var(--radius-sm);
}

.skip-link:focus {
    top: 0;
}

/* ===========================
   Container
   =========================== */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* ===========================
   Header
   =========================== */
header {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    padding: var(--spacing-xl) 0;
    box-shadow: var(--shadow-md);
}

header h1 {
    font-size: clamp(1.5rem, 5vw, 2.5rem);
    margin-bottom: var(--spacing-xs);
}

header .tagline {
    font-size: 0.95rem;
    opacity: 0.9;
}

/* ===========================
   Navigation
   =========================== */
nav {
    background-color: var(--bg-primary);
    border-bottom: 2px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 50;
    box-shadow: var(--shadow-sm);
}

.nav-list {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm) 0;
}

.nav-link {
    padding: var(--spacing-sm) var(--spacing-md);
    color: var(--text-secondary);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
    font-weight: 500;
}

.nav-link:hover,
.nav-link:focus {
    background-color: var(--bg-tertiary);
    color: var(--primary-color);
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

.nav-link.active {
    background-color: var(--primary-color);
    color: white;
}

/* ===========================
   Main Content
   =========================== */
main {
    flex: 1;
    padding: var(--spacing-xl) 0;
}

.content-section {
    display: none;
    animation: fadeIn var(--transition-normal);
}

.content-section.active {
    display: block;
}

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

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Section Headings */
section h2 {
    font-size: clamp(1.5rem, 4vw, 2rem);
    margin-bottom: var(--spacing-lg);
    color: var(--text-primary);
    border-bottom: 3px solid var(--primary-color);
    padding-bottom: var(--spacing-sm);
}

section h3 {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-md);
    color: var(--text-secondary);
}

/* ===========================
   Dashboard Statistics
   =========================== */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-xl);
}

.stat-card {
    background: var(--bg-primary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    text-align: center;
    transition: transform var(--transition-fast);
}

.stat-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.stat-card h3 {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-bottom: var(--spacing-sm);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.stat-value {
    font-size: 2rem;
    font-weight: bold;
    color: var(--primary-color);
}

/* ===========================
   Target/Cap Section
   =========================== */
.target-section {
    background: var(--bg-primary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    margin-bottom: var(--spacing-xl);
}

.target-display {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
    flex-wrap: wrap;
}

.target-display label {
    font-weight: 500;
}

.target-display input {
    padding: var(--spacing-sm);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-sm);
    width: 120px;
}

.progress-bar {
    width: 100%;
    height: 30px;
    background-color: var(--bg-tertiary);
    border-radius: var(--radius-lg);
    overflow: hidden;
    margin-bottom: var(--spacing-md);
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--primary-light));
    transition: width var(--transition-slow);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: bold;
    font-size: 0.85rem;
}

#target-status {
    padding: var(--spacing-sm);
    border-radius: var(--radius-sm);
    font-weight: 500;
}

/* ===========================
   Charts Section
   =========================== */
.charts-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-xl);
}

.chart-container {
    background: var(--bg-primary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    display: flex;
    flex-direction: column;
}

/* Bar Chart (Top Days) */
.bar-chart {
    min-height: 250px;
    display: flex;
    align-items: flex-end;
    justify-content: space-around;
    gap: var(--spacing-xs);
    padding: var(--spacing-md) 0;
    border-bottom: 2px solid var(--border-color);
    flex: 1;
}

.chart-bar {
    flex: 1;
    background: linear-gradient(180deg, var(--primary-light), var(--primary-color));
    border-radius: var(--radius-sm) var(--radius-sm) 0 0;
    position: relative;
    transition: all var(--transition-normal);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: flex-start;
    padding-top: var(--spacing-xs);
    cursor: pointer;
    min-height: 2px;
    /* Ensure visibility even if value is 0 */
}

.chart-bar:hover {
    background: linear-gradient(180deg, var(--primary-color), var(--primary-dark));
    transform: translateY(-2px);
}

.bar-label {
    color: white;
    font-weight: bold;
    font-size: 0.75rem;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.3);
}

.bar-day {
    position: absolute;
    bottom: -25px;
    font-size: 0.75rem;
    color: var(--text-secondary);
    font-weight: 500;
}

/* Pie Chart (Top Tags) */
.pie-chart-wrapper {
    display: flex;
    align-items: center;
    justify-content: space-around;
    flex-wrap: wrap;
    gap: var(--spacing-md);
    flex: 1;
}

.pie-chart {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    background: conic-gradient(var(--bg-tertiary) 0deg 360deg);
    position: relative;
    box-shadow: inset 0 0 0 2px rgba(255, 255, 255, 0.2);
}

.chart-legend {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.legend-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.legend-color {
    width: 12px;
    height: 12px;
    border-radius: 50%;
}

/* ===========================
   Controls Panel
   =========================== */
.controls-panel {
    background: var(--bg-primary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    margin-bottom: var(--spacing-lg);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.search-box,
.sort-controls {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.search-box label,
.sort-controls label {
    font-weight: 500;
}

.search-box input[type="text"] {
    flex: 1;
    min-width: 200px;
    padding: var(--spacing-sm);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-sm);
    transition: border-color var(--transition-fast);
}

.search-box input[type="text"]:focus {
    outline: none;
    border-color: var(--primary-color);
}

/* ===========================
   Books Table
   =========================== */
.table-responsive {
    overflow-x: auto;
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
}

.books-table {
    width: 100%;
    border-collapse: collapse;
}

.books-table thead {
    background-color: var(--bg-tertiary);
}

.books-table th,
.books-table td {
    padding: var(--spacing-md);
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.books-table th {
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    font-size: 0.85rem;
    letter-spacing: 0.5px;
}

.books-table tbody tr {
    transition: background-color var(--transition-fast);
}

.books-table tbody tr:hover {
    background-color: var(--bg-secondary);
}

/* Highlight matches */
mark {
    background-color: #fef08a;
    color: inherit;
    padding: 0 2px;
    border-radius: 2px;
}

/* Action buttons in table */
.action-btn {
    padding: var(--spacing-xs) var(--spacing-sm);
    margin-right: var(--spacing-xs);
    border: none;
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    transition: all var(--transition-fast);
}

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

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

.action-btn:hover,
.action-btn:focus {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
    outline: 2px solid currentColor;
    outline-offset: 2px;
}

/* ===========================
   Mobile Cards (hidden on desktop)
   =========================== */
.books-cards {
    display: none;
}

.book-card {
    background: var(--bg-primary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    margin-bottom: var(--spacing-md);
}

.book-card h3 {
    color: var(--primary-color);
    margin-bottom: var(--spacing-sm);
}

.book-card-field {
    display: flex;
    justify-content: space-between;
    padding: var(--spacing-xs) 0;
    border-bottom: 1px solid var(--border-color);
}

.book-card-field:last-child {
    border-bottom: none;
    padding-top: var(--spacing-md);
}

/* ===========================
   Forms
   =========================== */
#book-form {
    background: var(--bg-primary);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    max-width: 600px;
}

.form-group {
    margin-bottom: var(--spacing-lg);
}

.form-group label {
    display: block;
    margin-bottom: var(--spacing-xs);
    font-weight: 500;
    color: var(--text-secondary);
}

.required {
    color: var(--danger-color);
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-sm);
    transition: border-color var(--transition-fast);
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-group input:invalid:not(:placeholder-shown),
.form-group textarea:invalid:not(:placeholder-shown) {
    border-color: var(--danger-color);
}

.error-message {
    display: block;
    color: var(--danger-color);
    font-size: 0.85rem;
    margin-top: var(--spacing-xs);
    min-height: 1.2rem;
}

.hint {
    display: block;
    color: var(--text-muted);
    font-size: 0.85rem;
    margin-top: var(--spacing-xs);
}

/* ===========================
   Buttons
   =========================== */
.btn {
    padding: var(--spacing-sm) var(--spacing-lg);
    border: none;
    border-radius: var(--radius-sm);
    font-weight: 500;
    transition: all var(--transition-fast);
    cursor: pointer;
}

.btn:focus {
    outline: 2px solid currentColor;
    outline-offset: 2px;
}

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

.btn-primary:hover,
.btn-primary:focus {
    background-color: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

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

.btn-secondary:hover,
.btn-secondary:focus {
    background-color: var(--secondary-dark);
}

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

.btn-danger:hover,
.btn-danger:focus {
    background-color: #dc2626;
}

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

/* ===========================
   Settings
   =========================== */
.settings-group {
    background: var(--bg-primary);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    margin-bottom: var(--spacing-lg);
}

.setting-item {
    margin-bottom: var(--spacing-lg);
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.setting-item label {
    font-weight: 500;
    min-width: 200px;
}

/* ===========================
   About Section
   =========================== */
.about-content {
    background: var(--bg-primary);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
}

.about-content h3 {
    margin-top: var(--spacing-xl);
}

.about-content h3:first-child {
    margin-top: 0;
}

.about-content ul {
    list-style: disc;
    padding-left: var(--spacing-xl);
}

.about-content li {
    margin-bottom: var(--spacing-sm);
}

.about-content a {
    color: var(--primary-color);
    text-decoration: underline;
}

.about-content a:hover,
.about-content a:focus {
    color: var(--primary-dark);
}

/* ===========================
   Footer
   =========================== */
footer {
    background-color: var(--text-primary);
    color: white;
    padding: var(--spacing-lg) 0;
    text-align: center;
    margin-top: var(--spacing-2xl);
}

/* ===========================
   Status Messages & ARIA Live Regions
   =========================== */
[role="status"],
[aria-live] {
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-sm);
    margin-top: var(--spacing-md);
}

[role="status"]:not(:empty),
[aria-live]:not(:empty) {
    background-color: var(--bg-tertiary);
}

/* ===========================
   Focus Visible Styles (Accessibility)
   =========================== */
*:focus-visible {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

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

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}

/* ===========================
   Onboarding Modal
   =========================== */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    animation: fadeIn var(--transition-normal);
}

.modal-content {
    background: var(--bg-primary);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    max-width: 600px;
    width: 90%;
    text-align: center;
    position: relative;
    animation: slideUp var(--transition-normal);
}

.modal-content h2 {
    color: var(--primary-color);
    margin-bottom: var(--spacing-md);
    font-size: 1.5rem;
}

.modal-content p {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
    line-height: 1.6;
}

.modal-actions {
    display: flex;
    justify-content: center;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.modal-actions button {
    min-width: 150px;
}

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

    to {
        opacity: 1;
        transform: translateY(0);
    }
}