/* --- Global Reset & Variables --- */
:root {
    /* Colors (Dark Mode First) */
    --color-background: #121212;
    --color-surface: #1E1E1E;
    --color-card: #282828;
    --color-primary: #8C52FF; /* A vibrant purple */
    --color-primary-light: #A777FF;
    --color-text-primary: #E0E0E0;
    --color-text-secondary: #B0B0B0;
    --color-text-tertiary: #808080;
    --color-border: #333333;
    --color-success: #4CAF50;
    --color-error: #F44336;

    /* Spacing */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --spacing-xxl: 48px;

    /* Font Sizes */
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-md: 1.125rem;
    --font-size-lg: 1.5rem;
    --font-size-xl: 2rem;
    --font-size-xxl: 3rem;

    /* Border Radius */
    --border-radius-sm: 4px;
    --border-radius-md: 8px;
    --border-radius-lg: 12px;

    /* Box Shadow */
    --box-shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.12), 0 1px 2px rgba(0, 0, 0, 0.24);
    --box-shadow-md: 0 3px 6px rgba(0, 0, 0, 0.16), 0 3px 6px rgba(0, 0, 0, 0.23);
}

/* Light mode variables (override dark mode) */
body.light-mode {
    --color-background: #F0F2F5;
    --color-surface: #FFFFFF;
    --color-card: #FFFFFF;
    --color-primary: #6200EE; /* A darker purple for light mode */
    --color-primary-light: #9C27B0;
    --color-text-primary: #212121;
    --color-text-secondary: #757575;
    --color-text-tertiary: #BDBDBD;
    --color-border: #E0E0E0;
}


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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--color-background);
    color: var(--color-text-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    transition: background-color 0.3s ease, color 0.3s ease; /* Smooth mode switching */
}

a {
    color: var(--color-primary);
    text-decoration: none;
    transition: color 0.2s ease;
}

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

img {
    max-width: 100%;
    height: auto;
    display: block;
}

ul {
    list-style: none;
}

h1, h2, h3, h4, h5, h6 {
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-md);
    font-weight: 600;
}

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

/* --- Utility Classes --- */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-sm) var(--spacing-lg);
    border-radius: var(--border-radius-md);
    font-size: var(--font-size-base);
    font-weight: 500;
    cursor: pointer;
    border: none;
    transition: background-color 0.2s ease, color 0.2s ease, transform 0.1s ease;
}

.btn-primary {
    background-color: var(--color-primary);
    color: var(--color-surface); /* Text color for primary button */
}

.btn-primary:hover {
    background-color: var(--color-primary-light);
    transform: translateY(-1px);
}

.item-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-lg);
}

.item-card {
    background-color: var(--color-card);
    border-radius: var(--border-radius-md);
    overflow: hidden;
    padding: var(--spacing-md);
    box-shadow: var(--box-shadow-sm);
    text-align: center;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

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

.item-card img {
    width: 100%;
    height: 220px; /* Fixed height for consistency */
    object-fit: cover;
    border-radius: var(--border-radius-sm);
    margin-bottom: var(--spacing-md);
}

.item-card h3 {
    font-size: var(--font-size-base);
    margin-bottom: var(--spacing-xs);
    color: var(--color-text-primary);
}

.item-card p {
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
    margin-bottom: 0;
}

.content-section {
    padding: var(--spacing-xxl) 0;
}

.content-section h2 {
    font-size: var(--font-size-xl);
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

/* --- Component Imports --- */
/* We'll put specific component styles in their own files and use @import here,
   but for now, we'll write them directly below for simplicity. */

/* HEADER */
.header {
    background-color: var(--color-surface);
    padding: var(--spacing-md) 0;
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--box-shadow-sm);
}

.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: var(--spacing-lg);
}

.logo {
    font-size: var(--font-size-lg);
    font-weight: 700;
    color: var(--color-primary);
}

.search-bar {
    flex-grow: 1;
    display: flex;
    align-items: center;
    background-color: var(--color-card);
    border-radius: var(--border-radius-md);
    padding: var(--spacing-sm) var(--spacing-md);
    max-width: 500px;
}

.search-bar i {
    color: var(--color-text-secondary);
    margin-right: var(--spacing-sm);
}

.search-bar input {
    border: none;
    background: transparent;
    color: var(--color-text-primary);
    font-size: var(--font-size-base);
    width: 100%;
    outline: none;
}

.search-bar input::placeholder {
    color: var(--color-text-tertiary);
}

.user-actions {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.user-actions .btn {
    padding: var(--spacing-sm) var(--spacing-lg);
}

.user-menu-toggle {
    display: flex;
    align-items: center;
    cursor: pointer;
    position: relative;
    /* Temporarily hide until user is logged in */
    display: none; 
}

.user-menu-toggle .avatar {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    object-fit: cover;
    margin-right: var(--spacing-sm);
    border: 1px solid var(--color-border);
}

.user-menu-toggle i {
    color: var(--color-text-secondary);
    font-size: var(--font-size-md);
}

.menu-toggle-btn {
    background: none;
    border: none;
    color: var(--color-text-primary);
    font-size: var(--font-size-xl);
    cursor: pointer;
    display: none; /* Hidden on desktop, shown on mobile */
}

/* HERO SECTION */
.hero {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-xxl) 0;
    gap: var(--spacing-xl);
    min-height: 500px;
}

.hero-content {
    flex: 1;
    max-width: 600px;
}

.hero-content h1 {
    font-size: var(--font-size-xxl);
    line-height: 1.1;
    margin-bottom: var(--spacing-md);
}

.hero-content p {
    font-size: var(--font-size-lg);
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-xl);
}

.hero-images {
    position: relative;
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 300px; /* Ensure space even without images */
}

.book-cover {
    position: absolute;
    border-radius: var(--border-radius-md);
    box-shadow: var(--box-shadow-md);
    transition: transform 0.5s ease;
}

.book-cover-1 {
    width: 180px;
    height: 250px;
    transform: rotate(-8deg) translateX(-60px);
    z-index: 2;
}

.book-cover-2 {
    width: 200px;
    height: 280px;
    transform: rotate(4deg) translateX(60px) translateY(-20px);
    z-index: 3;
}
/* Add more book covers if desired, adjust positions */


/* CATEGORY GRID */
.category-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-lg);
}

.category-card {
    background-color: var(--color-card);
    border-radius: var(--border-radius-md);
    padding: var(--spacing-xl) var(--spacing-md);
    text-align: center;
    box-shadow: var(--box-shadow-sm);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

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

.category-card i {
    font-size: var(--font-size-xl); /* Increased icon size */
    color: var(--color-primary);
    margin-bottom: var(--spacing-md);
}

.category-card h3 {
    font-size: var(--font-size-base);
    margin-bottom: 0;
    color: var(--color-text-primary);
}

/* NEWS & ANNOUNCEMENTS */
.news-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-lg);
}

.news-card {
    background-color: var(--color-card);
    border-radius: var(--border-radius-md);
    padding: var(--spacing-lg);
    box-shadow: var(--box-shadow-sm);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.news-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--box-shadow-md);
}

.news-card h3 {
    font-size: var(--font-size-md);
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-sm);
}

.news-card p {
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
    margin-bottom: 0;
}


/* FOOTER */
.footer {
    background-color: var(--color-surface);
    padding: var(--spacing-xxl) 0;
    border-top: 1px solid var(--color-border);
    color: var(--color-text-secondary);
    margin-top: var(--spacing-xxl);
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-xl);
}

.footer-brand .logo {
    margin-bottom: var(--spacing-md);
}

.footer-brand p {
    font-size: var(--font-size-sm);
    color: var(--color-text-tertiary);
}

.footer-links h4, .footer-social h4 {
    font-size: var(--font-size-base);
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-md);
}

.footer-links ul li {
    margin-bottom: var(--spacing-sm);
}

.footer-links ul li a {
    color: var(--color-text-secondary);
    font-size: var(--font-size-sm);
}

.footer-links ul li a:hover {
    color: var(--color-primary);
}

.social-icons {
    display: flex;
    gap: var(--spacing-md);
}

.social-icons a {
    color: var(--color-text-secondary);
    font-size: var(--font-size-lg);
}

.social-icons a:hover {
    color: var(--color-primary);
}

/* --- Responsive Design (Basic) --- */
@media (max-width: 992px) {
    .navbar {
        flex-wrap: wrap;
        justify-content: center;
    }

    .search-bar {
        order: 3; /* Move search bar below logo and user actions */
        flex-basis: 100%; /* Take full width */
        margin-top: var(--spacing-md);
    }

    .user-actions {
        order: 2;
    }

    .menu-toggle-btn {
        display: block; /* Show hamburger menu on smaller screens */
    }

    .hero {
        flex-direction: column;
        text-align: center;
    }

    .hero-content {
        max-width: 100%;
    }

    .hero-images {
        margin-top: var(--spacing-xl);
        min-height: 250px;
    }

    .book-cover-1 {
        width: 150px;
        height: 210px;
        transform: rotate(-8deg) translateX(-40px);
    }

    .book-cover-2 {
        width: 170px;
        height: 230px;
        transform: rotate(4deg) translateX(40px) translateY(-10px);
    }

    .content-section h2 {
        font-size: var(--font-size-xl);
    }
}

@media (max-width: 768px) {
    .container {
        padding: 0 var(--spacing-sm);
    }

    .navbar {
        gap: var(--spacing-sm);
    }

    .logo {
        font-size: var(--font-size-md);
    }

    .hero-content h1 {
        font-size: var(--font-size-xl);
    }

    .hero-content p {
        font-size: var(--font-size-base);
    }

    .item-grid, .category-grid, .news-list {
        grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
        gap: var(--spacing-md);
    }
    
    .item-card img {
        height: 180px;
    }

    .footer-grid {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .footer-brand .logo {
        margin-left: auto;
        margin-right: auto;
    }

    .footer-social {
        display: flex;
        flex-direction: column;
        align-items: center;
    }

    .footer-social .social-icons {
        margin-top: var(--spacing-md);
    }
}

@media (max-width: 480px) {
    .hero {
        min-height: 400px;
    }
    .hero-images {
        min-height: 200px;
    }
    .book-cover-1, .book-cover-2 {
        width: 120px;
        height: 170px;
        transform: none !important; /* Reset transform for very small screens */
        position: static; /* Remove absolute positioning */
        margin: var(--spacing-sm) auto;
    }
    .hero-images {
        flex-direction: row; /* Stack them horizontally */
        flex-wrap: wrap; /* Allow wrapping */
        justify-content: center;
        gap: var(--spacing-md);
    }
    .hero-content button {
        width: 100%;
    }
}