/* ===== OpenShelf Mobile-First CSS ===== */
:root {
    /* Colors */
    --primary: #2C3E50;
    --primary-dark: #1a252f;
    --primary-light: #3e5871;
    --secondary: #4C9F8A;
    --success: #2E8B57;
    --warning: #D9A441;
    --danger: #C65D5D;
    --dark: #0F172A;
    --gray-100: #F8F9FA;
    --gray-200: #E2E8F0;
    --gray-300: #dee2e6;
    --gray-400: #ced4da;
    --gray-500: #adb5bd;
    --gray-600: #5A6C7D;
    --gray-700: #4a5568;
    --gray-800: #0F172A;
    --white: #ffffff;
    
    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-xxl: 3rem;
    
    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-md: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-xxl: 1.5rem;
    --font-size-xxxl: 2rem;
    
    /* Shadows */
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.05);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.08);
    --shadow-lg: 0 10px 15px rgba(0,0,0,0.08);
    --shadow-xl: 0 20px 25px rgba(0,0,0,0.1);
    
    /* Borders */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 20px;
    --radius-full: 9999px;
    
    /* Transitions */
    --transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    
    /* Logo Colors */
    --logo-gradient: linear-gradient(135deg, #2C3E50 0%, #4C9F8A 100%);
}


/* ===== Reset & Base ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    font-size: var(--font-size-md);
    line-height: 1.6;
    color: var(--gray-800);
    background: var(--gray-100);
    min-height: 100vh;
}

/* ===== Typography ===== */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: var(--space-md);
    color: var(--dark);
}

h1 { font-size: var(--font-size-xxxl); }
h2 { font-size: var(--font-size-xxl); }
h3 { font-size: var(--font-size-xl); }
h4 { font-size: var(--font-size-lg); }

p { margin-bottom: var(--space-md); }

a {
    color: var(--primary);
    text-decoration: none;
    transition: var(--transition);
}

a:hover {
    color: var(--primary-dark);
}

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

/* ===== Logo Styles ===== */
.logo-wrapper {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    transition: var(--transition);
}

.logo-icon {
    width: 42px;
    height: 42px;
    background: var(--logo-gradient);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.4rem;
    box-shadow: 0 4px 12px rgba(44, 62, 80, 0.2);
    transition: var(--transition);
}

.logo-text {
    display: flex;
    flex-direction: column;
    line-height: 1.1;
}

.logo-name {
    font-size: 1.45rem;
    font-weight: 850;
    letter-spacing: -1px;
}

.logo-name .text-primary {
    color: #2C3E50;
}

.logo-name .text-secondary {
    color: #4C9F8A;
}

.navbar-brand:hover .logo-wrapper {
    transform: scale(1.02);
}

.navbar-brand:hover .logo-icon {
    transform: rotate(-5deg) scale(1.1);
    box-shadow: 0 6px 16px rgba(76, 159, 138, 0.3);
}

.navbar {
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(15px);
    -webkit-backdrop-filter: blur(15px);
    border-bottom: 1px solid rgba(226, 232, 240, 0.8);
    position: sticky;
    top: 0;
    z-index: 1000;
    padding: 0.75rem 0;
    transition: var(--transition);
}

.navbar.scrolled {
    padding: 0.5rem 0;
    background: rgba(255, 255, 255, 0.95);
    box-shadow: var(--shadow-md);
}

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

.nav-toggle {
    display: block;
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--gray-600);
    cursor: pointer;
    padding: var(--space-xs);
    transition: var(--transition);
}

.nav-toggle:hover {
    color: var(--primary);
}

.nav-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: white;
    padding: var(--space-md);
    box-shadow: var(--shadow-lg);
    border-bottom: 1px solid var(--gray-200);
    animation: slideDown 0.3s ease;
}

.nav-menu.show {
    display: block;
}

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

.nav-list {
    list-style: none;
}

.nav-item {
    margin-bottom: var(--space-xs);
}

.nav-link {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm) var(--space-md);
    color: var(--gray-700);
    border-radius: var(--radius-md);
    transition: var(--transition);
}

.nav-link i {
    width: 20px;
    color: var(--primary);
}

.nav-link:hover {
    background: var(--gray-100);
    color: var(--primary);
}

.nav-link.active {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
}

.nav-link.active i {
    color: white;
}

.nav-badge {
    margin-left: auto;
    background: var(--danger);
    color: white;
    font-size: var(--font-size-xs);
    padding: 0.2rem 0.5rem;
    border-radius: var(--radius-full);
}

/* Profile Dropdown */
.profile-trigger {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    padding: var(--space-xs);
    border-radius: var(--radius-full);
    cursor: pointer;
    transition: var(--transition);
}

.profile-trigger:hover {
    background: var(--gray-100);
}

.profile-image {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    object-fit: cover;
    border: 2px solid var(--primary-light);
}

.dropdown-menu {
    display: none;
    position: absolute;
    top: 100%;
    right: 0;
    background: white;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    min-width: 200px;
    z-index: 1000;
    overflow: hidden;
}

.dropdown-menu.show {
    display: block;
    animation: slideDown 0.3s ease;
}

.dropdown-item {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm) var(--space-md);
    color: var(--gray-700);
    transition: var(--transition);
    border-left: 3px solid transparent;
}

.dropdown-item i {
    width: 20px;
    color: var(--primary);
}

.dropdown-item:hover {
    background: var(--gray-100);
    border-left-color: var(--primary);
}

.dropdown-divider {
    height: 1px;
    background: var(--gray-200);
    margin: var(--space-xs) 0;
}

/* ===== Main Content ===== */
.main-content {
    min-height: calc(100vh - 140px);
    padding: var(--space-xs) 0;
}

/* ===== Cards ===== */
.card {
    background: white;
    border-radius: var(--radius-xl);
    padding: var(--space-lg);
    box-shadow: var(--shadow-md);
    transition: var(--transition);
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--space-md);
    padding-bottom: var(--space-sm);
    border-bottom: 1px solid var(--gray-200);
}

.card-title {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--dark);
    margin: 0;
}

/* ===== Grid Layouts ===== */
.grid {
    display: grid;
    gap: var(--space-md);
}

.grid-2, .grid-3, .grid-4 {
    grid-template-columns: 1fr;
}

/* ===== Book Cards (Ultra Modern) ===== */



/* ===== Buttons ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-xs);
    padding: var(--space-sm) var(--space-lg);
    border: none;
    border-radius: var(--radius-md);
    font-size: var(--font-size-sm);
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(102, 126, 234, 0.3);
}

.btn-outline {
    background: transparent;
    border: 2px solid var(--primary);
    color: var(--primary);
}

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

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

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

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

.btn-sm {
    padding: var(--space-xs) var(--space-sm);
    font-size: var(--font-size-xs);
}

.btn-block {
    width: 100%;
}

/* ===== Forms ===== */
.form-group {
    margin-bottom: var(--space-md);
}

.form-label {
    display: block;
    margin-bottom: var(--space-xs);
    font-weight: 600;
    color: var(--dark);
    font-size: var(--font-size-sm);
}

.form-label i {
    color: var(--primary);
    margin-right: var(--space-xs);
}

.form-input,
.form-select,
.form-textarea {
    width: 100%;
    padding: var(--space-sm) var(--space-md);
    border: 2px solid var(--gray-200);
    border-radius: var(--radius-md);
    font-size: var(--font-size-sm);
    transition: var(--transition);
    background: white;
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.form-textarea {
    min-height: 100px;
    resize: vertical;
}

.form-error {
    color: var(--danger);
    font-size: var(--font-size-xs);
    margin-top: var(--space-xs);
    display: flex;
    align-items: center;
    gap: var(--space-xs);
}

/* ===== Alerts ===== */
.alert {
    padding: var(--space-sm) var(--space-md);
    border-radius: var(--radius-md);
    margin-bottom: var(--space-md);
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-size: var(--font-size-sm);
    animation: slideIn 0.3s ease;
}

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

.alert-success {
    background: rgba(45, 206, 137, 0.1);
    border: 2px solid var(--success);
    color: var(--success);
}

.alert-warning {
    background: rgba(251, 99, 64, 0.1);
    border: 2px solid var(--warning);
    color: var(--warning);
}

.alert-danger {
    background: rgba(245, 54, 92, 0.1);
    border: 2px solid var(--danger);
    color: var(--danger);
}

.alert-info {
    background: rgba(102, 126, 234, 0.1);
    border: 2px solid var(--primary);
    color: var(--primary);
}

/* ===== Footer ===== */
.footer {
    background: white;
    padding: var(--space-xl) 0 var(--space-md);
    border-top: 1px solid var(--gray-200);
}

.footer-content {
    display: grid;
    gap: var(--space-xl);
    margin-bottom: var(--space-xl);
}

.footer-section h3 {
    font-size: var(--font-size-lg);
    margin-bottom: var(--space-md);
    color: var(--dark);
}

.footer-section p {
    color: var(--gray-600);
    margin-bottom: var(--space-sm);
}

.footer-section ul {
    list-style: none;
}

.footer-section li {
    margin-bottom: var(--space-xs);
}

.footer-section a {
    color: var(--gray-600);
    transition: var(--transition);
}

.footer-section a:hover {
    color: var(--primary);
    padding-left: var(--space-xs);
}

.social-links {
    display: flex;
    gap: var(--space-md);
}

.social-links a {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: var(--gray-100);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary);
    transition: var(--transition);
}

.social-links a:hover {
    background: var(--primary);
    color: white;
    transform: translateY(-3px);
}

.footer-bottom {
    text-align: center;
    padding-top: var(--space-lg);
    border-top: 1px solid var(--gray-200);
    color: var(--gray-600);
    font-size: var(--font-size-sm);
}

/* ===== Loading Spinner ===== */
.spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--gray-200);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto;
}

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

/* ===== Modal ===== */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 2000;
    align-items: center;
    justify-content: center;
    padding: var(--space-md);
}

.modal.active {
    display: flex;
}

.modal-content {
    background: white;
    border-radius: var(--radius-xl);
    max-width: 500px;
    width: 100%;
    max-height: 90vh;
    overflow-y: auto;
    animation: modalSlideUp 0.3s ease;
}

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

.modal-header {
    padding: var(--space-lg);
    border-bottom: 1px solid var(--gray-200);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-header h3 {
    margin: 0;
    display: flex;
    align-items: center;
    gap: var(--space-xs);
}

.modal-close {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--gray-600);
    transition: var(--transition);
}

.modal-close:hover {
    color: var(--danger);
}

.modal-body {
    padding: var(--space-lg);
}

/* ===== Tablet Styles (576px and up) ===== */
@media screen and (min-width: 576px) {
    .book-grid {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .grid-2 {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* ===== Desktop Styles (768px and up) ===== */
@media screen and (min-width: 768px) {
    :root {
        --font-size-xxxl: 2.5rem;
    }
    
    .nav-toggle {
        display: none;
    }
    
    .nav-menu {
        display: block;
        position: static;
        background: none;
        box-shadow: none;
        padding: 0;
        border: none;
    }
    
    .nav-list {
        display: flex;
        align-items: center;
        gap: var(--space-lg);
    }
    
    .nav-item {
        margin-bottom: 0;
    }
    
    .nav-link {
        padding: var(--space-sm) 0;
        border-radius: 0;
        border-bottom: 2px solid transparent;
    }
    
    .nav-link:hover {
        background: none;
        border-bottom-color: var(--primary);
    }
    
    .nav-link.active {
        background: none;
        color: var(--primary);
        border-bottom-color: var(--primary);
    }
    
    .nav-link.active i {
        color: var(--primary);
    }
    
    .profile-dropdown {
        position: relative;
    }
    
    .book-grid {
        grid-template-columns: repeat(4, 1fr);
    }
    
    .grid-3 {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .grid-4 {
        grid-template-columns: repeat(4, 1fr);
    }
    
    .footer-content {
        grid-template-columns: repeat(3, 1fr);
    }
}

/* ===== Large Desktop Styles (1024px and up) ===== */
@media screen and (min-width: 1024px) {
    .book-grid {
        grid-template-columns: repeat(5, 1fr);
    }
    
    .container {
        padding: 0 var(--space-xl);
    }
}

/* ===== Utility Classes ===== */
.text-center { text-align: center; }
.text-right { text-align: right; }
.text-primary { color: var(--primary); }
.text-success { color: var(--success); }
.text-warning { color: var(--warning); }
.text-danger { color: var(--danger); }

.mt-1 { margin-top: var(--space-xs); }
.mt-2 { margin-top: var(--space-sm); }
.mt-3 { margin-top: var(--space-md); }
.mt-4 { margin-top: var(--space-lg); }
.mt-5 { margin-top: var(--space-xl); }

.mb-1 { margin-bottom: var(--space-xs); }
.mb-2 { margin-bottom: var(--space-sm); }
.mb-3 { margin-bottom: var(--space-md); }
.mb-4 { margin-bottom: var(--space-lg); }
.mb-5 { margin-bottom: var(--space-xl); }

.p-1 { padding: var(--space-xs); }
.p-2 { padding: var(--space-sm); }
.p-3 { padding: var(--space-md); }
.p-4 { padding: var(--space-lg); }
.p-5 { padding: var(--space-xl); }

/* ===== Reset & Base ===== */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

.flex { display: flex; }
.flex-column { flex-direction: column; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.justify-center { justify-content: center; }
.gap-1 { gap: var(--space-xs); }
.gap-2 { gap: var(--space-sm); }
.gap-3 { gap: var(--space-md); }

/* ===== Dark Mode ===== */
:root[data-theme="dark"] {
    --primary: #5c85b0;
    --primary-dark: #436b95;
    --primary-light: #8ab4dd;
    --secondary: #4C9F8A;
    --success: #34d399;
    --warning: #fb923c;
    --danger: #f87171;
    --dark: #f8fafc;
    --gray-100: #1e293b;
    --gray-200: #334155;
    --gray-300: #475569;
    --gray-400: #64748b;
    --gray-500: #94a3b8;
    --gray-600: #cbd5e1;
    --gray-700: #e2e8f0;
    --gray-800: #f1f5f9;
    --white: #0f172a;
}

[data-theme="dark"] body {
    background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
    color: var(--gray-800);
}

[data-theme="dark"] .card, 
[data-theme="dark"] .header, 
[data-theme="dark"] .nav-menu, 
[data-theme="dark"] .dropdown-menu, 
[data-theme="dark"] .footer, 
[data-theme="dark"] .modal-content, 
[data-theme="dark"] .book-card,
[data-theme="dark"] .admin-card {
    background: #1e293b;
    border-color: #334155;
    box-shadow: 0 4px 6px rgba(0,0,0,0.3);
}

[data-theme="dark"] .form-input, 
[data-theme="dark"] .form-select, 
[data-theme="dark"] .form-textarea {
    background: #0f172a;
    border-color: #334155;
    color: var(--gray-800);
}

[data-theme="dark"] .form-input:focus, 
[data-theme="dark"] .form-select:focus, 
[data-theme="dark"] .form-textarea:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(129, 140, 248, 0.2);
}

[data-theme="dark"] .book-cover {
    background: linear-gradient(45deg, #1e293b, #334155);
}

[data-theme="dark"] h1, 
[data-theme="dark"] h2, 
[data-theme="dark"] h3, 
[data-theme="dark"] h4, 
[data-theme="dark"] h5, 
[data-theme="dark"] h6,
[data-theme="dark"] .card-title,
[data-theme="dark"] .book-title {
    color: #f8fafc;
}

[data-theme="dark"] .book-author {
    color: var(--gray-600);
}

[data-theme="dark"] .card-header, 
[data-theme="dark"] .dropdown-divider, 
[data-theme="dark"] .book-owner, 
[data-theme="dark"] .modal-header,
[data-theme="dark"] .footer-bottom {
    border-color: #334155;
}

[data-theme="dark"] .book-category {
    background: #334155;
    color: #cbd5e1;
}

[data-theme="dark"] .social-links a {
    background: #334155;
    color: var(--primary);
}

[data-theme="dark"] .social-links a:hover {
    background: var(--primary);
    color: #0f172a;
}

[data-theme="dark"] .alert-success {
    background: rgba(52, 211, 153, 0.1);
    border-color: rgba(52, 211, 153, 0.3);
    color: #34d399;
}

[data-theme="dark"] .alert-warning {
    background: rgba(251, 146, 60, 0.1);
    border-color: rgba(251, 146, 60, 0.3);
    color: #fb923c;
}

[data-theme="dark"] .alert-danger, 
[data-theme="dark"] .alert-error {
    background: rgba(248, 113, 113, 0.1);
    border-color: rgba(248, 113, 113, 0.3);
    color: #f87171;
}



[data-theme="dark"] .alert-info {
    background: rgba(92, 133, 176, 0.1);
    border-color: rgba(92, 133, 176, 0.3);
    color: var(--primary);
}

[data-theme="dark"] .form-label, 
[data-theme="dark"] p,
[data-theme="dark"] .footer-section p {
    color: #cbd5e1;
}

[data-theme="dark"] .nav-link,
[data-theme="dark"] .dropdown-item {
    color: #e2e8f0;
}

[data-theme="dark"] .nav-link:hover, 
[data-theme="dark"] .dropdown-item:hover {
    background: #334155;
    color: var(--primary);
}

[data-theme="dark"] .footer-section a {
    color: #cbd5e1;
}

[data-theme="dark"] .footer-section a:hover {
    color: var(--primary);
}

[data-theme="dark"] .modal-close {
    color: #cbd5e1;
}

[data-theme="dark"] .modal-close:hover {
    color: #f87171;
}

/* ===== Responsive View Switcher ===== */
/* Force hide both by default using high specificity */
body .hide-on-mobile, 
body .show-on-mobile,
body [id^="desktop-view-wrapper"],
body [id^="mobile-view-wrapper"] { 
    display: none !important; 
}

/* Desktop/Tablet view (> 768px) */
@media screen and (min-width: 769px) {
    body .hide-on-mobile,
    body [id^="desktop-view-wrapper"] { 
        display: block !important; 
    }
}

/* Mobile view (<= 768px) */
@media screen and (max-width: 768px) {
    body .show-on-mobile,
    body [id^="mobile-view-wrapper"] { 
        display: block !important; 
    }
}