@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap');

:root {
    /* Light Mode */
    --bg-color: #f8fafc;
    --text-color: #1e293b;
    --header-bg: rgba(255, 255, 255, 0.8);
    --header-text: #0f172a;
    --header-border: rgba(0, 0, 0, 0.05);
    --link-color: #3b82f6;
    --link-hover: #2563eb;
    --button-bg: #3b82f6;
    --button-bg-hover: #2563eb;
    --button-text: #ffffff;
    --card-bg: #ffffff;
    --card-border: #e2e8f0;
    --card-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
    --card-shadow-hover: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --input-bg: #ffffff;
    --input-border: #cbd5e1;
    --input-text: #1e293b;
}

.dark {
    /* Dark Mode */
    --bg-color: #0f172a;
    --text-color: #f8fafc;
    --header-bg: rgba(15, 23, 42, 0.8);
    --header-text: #f8fafc;
    --header-border: rgba(255, 255, 255, 0.1);
    --link-color: #60a5fa;
    --link-hover: #93c5fd;
    --button-bg: #3b82f6;
    --button-bg-hover: #60a5fa;
    --button-text: #ffffff;
    --card-bg: #1e293b;
    --card-border: #334155;
    --card-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.2), 0 2px 4px -1px rgba(0, 0, 0, 0.1);
    --card-shadow-hover: 0 10px 15px -3px rgba(0, 0, 0, 0.4), 0 4px 6px -2px rgba(0, 0, 0, 0.2);
    --input-bg: #1e293b;
    --input-border: #475569;
    --input-text: #f8fafc;
}

* {
    box-sizing: border-box;
    transition: background-color 0.3s ease, border-color 0.3s ease, color 0.3s ease;
}

body {
    margin: 0;
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    line-height: 1.5;
}

/* Glassmorphism Header */
header {
    background-color: var(--header-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--header-border);
    color: var(--header-text);
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 1000;
}

header h1 {
    margin: 0;
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: -0.025em;
    background: linear-gradient(135deg, var(--link-color), #8b5cf6);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

nav {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

nav a, nav button {
    color: var(--header-text);
    text-decoration: none;
    background: none;
    border: none;
    cursor: pointer;
    font-size: 0.95rem;
    font-weight: 500;
    padding: 0.5rem;
    border-radius: 6px;
    transition: all 0.2s ease;
}

nav a:hover, nav button:hover {
    color: var(--link-color);
    transform: translateY(-1px);
    background-color: rgba(128, 128, 128, 0.1);
}

#logout-link:hover {
    color: var(--header-text);
    transform: translateY(-1px);
}

.btn-primary {
    background-color: var(--button-bg) !important;
    color: var(--button-text) !important;
    padding: 0.5rem 1.25rem !important;
    border-radius: 8px !important;
    font-weight: 600 !important;
    box-shadow: 0 2px 4px rgba(59, 130, 246, 0.3);
}

.btn-primary:hover {
    background-color: var(--button-bg-hover) !important;
    transform: translateY(-1px);
    box-shadow: 0 4px 6px rgba(59, 130, 246, 0.4);
}

#toggle-theme {
    font-size: 1.2rem;
    padding: 0.4rem;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

main {
    flex: 1;
    padding: 2rem;
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
}

footer {
    background-color: transparent;
    border-top: 1px solid var(--card-border);
    color: var(--text-color);
    text-align: center;
    padding: 1.5rem;
    font-size: 0.875rem;
    opacity: 0.8;
}

/* Typography */
h2, h3 {
    font-weight: 600;
    margin-top: 0;
    letter-spacing: -0.025em;
}

/* Forms & Inputs */
input[type="text"], 
input[type="number"], 
input[type="password"], 
input[type="email"], 
select, 
textarea {
    width: 100%;
    padding: 0.75rem 1rem;
    border-radius: 8px;
    border: 1px solid var(--input-border);
    background-color: var(--input-bg);
    color: var(--input-text);
    font-family: inherit;
    font-size: 0.95rem;
    outline: none;
    transition: all 0.2s ease;
    margin-top: 0.5rem;
}

input:focus, select:focus, textarea:focus {
    border-color: var(--link-color);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.2);
}

label {
    font-weight: 500;
    font-size: 0.9rem;
    display: block;
    margin-bottom: 1rem;
}

button {
    padding: 0.75rem 1.5rem;
    background-color: var(--button-bg);
    color: var(--button-text);
    border: none;
    cursor: pointer;
    border-radius: 8px;
    font-weight: 500;
    font-size: 0.95rem;
    transition: all 0.2s ease;
    display: inline-flex;
    justify-content: center;
    align-items: center;
}

button:hover {
    background-color: var(--button-bg-hover);
    transform: translateY(-1px);
    box-shadow: 0 4px 6px -1px rgba(59, 130, 246, 0.3);
}

button:active {
    transform: translateY(0);
}

/* Specific button styles */
#search-button {
    padding: 0.75rem 1.5rem;
}

/* Card Styling (Premium Look) */
.book-card {
    background-color: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 16px;
    box-shadow: var(--card-shadow);
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.book-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--link-color), #8b5cf6);
    opacity: 0;
    transition: opacity 0.3s ease;
}

.book-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--card-shadow-hover);
    border-color: var(--link-color);
}

.book-card:hover::before {
    opacity: 1;
}

.book-card img.book-thumbnail {
    width: 100%;
    height: 220px;
    object-fit: cover;
    border-radius: 8px;
    margin-bottom: 1.25rem;
    transition: transform 0.3s ease;
}

.book-card:hover img.book-thumbnail {
    transform: scale(1.02);
}

.book-card h3 {
    margin: 0 0 0.5rem 0;
    font-size: 1.25rem;
}

.book-card p {
    margin: 0.25rem 0;
    color: var(--text-color);
    opacity: 0.8;
    font-size: 0.9rem;
}

.book-card .actions {
    margin-top: 1.5rem;
    display: flex;
    gap: 0.75rem;
}

.book-card .actions button {
    flex: 1;
    padding: 0.6rem;
    font-size: 0.9rem;
}

.book-card .actions button.view-book {
    background-color: transparent;
    color: var(--link-color);
    border: 1px solid var(--link-color);
}

.book-card .actions button.view-book:hover {
    background-color: rgba(59, 130, 246, 0.1);
}

/* Search Section */
#search-section {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    background-color: var(--card-bg);
    padding: 1rem;
    border-radius: 12px;
    box-shadow: var(--card-shadow);
    border: 1px solid var(--card-border);
}

#search-section input {
    flex: 2;
    margin-top: 0;
}

#search-section select {
    flex: 1;
    margin-top: 0;
}

/* Grid Layout */
#books-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 2rem;
}

/* Pagination */
#pagination {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1.5rem;
    margin-top: 3rem;
}

#page-info {
    font-weight: 600;
    background-color: var(--card-bg);
    padding: 0.5rem 1rem;
    border-radius: 8px;
    border: 1px solid var(--card-border);
}

/* Error messages */
.error {
    color: #ef4444;
    background-color: rgba(239, 68, 68, 0.1);
    padding: 0.75rem;
    border-radius: 8px;
    margin-bottom: 1rem;
    font-size: 0.9rem;
    font-weight: 500;
}

/* Modals & Forms */
form {
    background-color: var(--card-bg);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--card-shadow);
    border: 1px solid var(--card-border);
    max-width: 600px;
    margin: 0 auto 2rem auto;
}

#edit-book-modal {
    background-color: var(--bg-color);
    border-radius: 16px;
    border: 1px solid var(--card-border);
    box-shadow: var(--card-shadow-hover);
    max-width: 600px;
    margin: 2rem auto;
    padding: 0;
    overflow: hidden;
}

#edit-book-modal h3 {
    background-color: var(--card-bg);
    padding: 1.5rem 2rem;
    margin: 0;
    border-bottom: 1px solid var(--card-border);
}

#edit-book-modal form {
    box-shadow: none;
    border: none;
    margin: 0;
}

/* Tables / Lists (Cart, Orders) */
.cart-item, .order, .user, .review {
    background-color: var(--card-bg);
    border: 1px solid var(--card-border);
    padding: 1.25rem;
    border-radius: 12px;
    margin-bottom: 1rem;
    box-shadow: var(--card-shadow);
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
}

.cart-item input.cart-qty {
    width: 70px;
    margin: 0 1rem;
}

.remove-cart, .delete-book, .delete-user {
    background-color: transparent;
    color: #ef4444;
    border: 1px solid #ef4444;
}

.remove-cart:hover, .delete-book:hover, .delete-user:hover {
    background-color: rgba(239, 68, 68, 0.1);
    box-shadow: none;
}

/* Profile specific */
#profile-info {
    background-color: var(--card-bg);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--card-shadow);
    border: 1px solid var(--card-border);
    margin-bottom: 2rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}

#profile-photo-display {
    box-shadow: 0 4px 10px rgba(0,0,0,0.1);
    border: 3px solid var(--bg-color);
}