/* ==========================================================================
   BookParcham - Premium App-Like UI
   Features: Expanding Search, Smart Thumbnails, Horizontal to Grid Layouts
   ========================================================================== */

:root {
    /* Deep Dark App Theme */
    --bg-base: #0f0f13;       
    --bg-surface: #18181c;    
    --bg-elevated: #222227;   
    --bg-navbar: rgba(15, 15, 19, 0.95); 

    /* Typography */
    --text-primary: #ffffff;
    --text-secondary: #a1a1aa; 
    
    /* Accents */
    --accent-blue: #3b82f6; 
    --accent-green: #10b981;
    --accent-hover: #2563eb;
    
    /* Borders & Shadows */
    --border: rgba(255, 255, 255, 0.08);
    --border-hover: rgba(255, 255, 255, 0.15);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.5);
    
    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-smooth: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

* { 
    margin: 0; 
    padding: 0; 
    box-sizing: border-box; 
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    -webkit-tap-highlight-color: transparent;
}

body { 
    background-color: var(--bg-base); 
    color: var(--text-primary); 
    padding-bottom: 80px; /* Space for bottom nav */
    overflow-x: hidden;
}

.container { 
    max-width: 1200px; 
    margin: 0 auto; 
    padding: 0 1rem; 
}

.mb-section { 
    margin-bottom: 2.5rem; 
}

/* --- Top Navigation & Expanding Search --- */
.top-nav { 
    position: sticky; 
    top: 0; 
    background-color: var(--bg-navbar); 
    backdrop-filter: blur(12px); 
    -webkit-backdrop-filter: blur(12px);
    z-index: 50; 
    padding: 1rem 0; 
    border-bottom: 1px solid var(--border); 
}

.nav-content { 
    display: flex; 
    align-items: center; 
    justify-content: space-between; 
    gap: 1rem; 
}

.logo { 
    font-size: 1.25rem; 
    font-weight: 700; 
    white-space: nowrap;
}

.nav-controls {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    flex-grow: 1;
    justify-content: flex-end;
}

/* The Expanding Search Bar Magic */
.search-container { 
    position: relative; 
    width: 40px; /* Starts as just an icon size */
    transition: width var(--transition-smooth); 
    overflow: hidden;
    border-radius: 8px;
    background-color: transparent;
}

.search-container:focus-within,
.search-container.active { 
    width: 100%; 
    max-width: 350px; 
    background-color: var(--bg-surface);
}

.search-icon { 
    position: absolute; 
    left: 12px; 
    top: 50%; 
    transform: translateY(-50%); 
    color: var(--text-secondary); 
    z-index: 2;
    pointer-events: none;
}

.search-input { 
    width: 100%; 
    background: transparent; 
    border: 1px solid transparent; 
    color: var(--text-primary); 
    padding: 0.6rem 1rem 0.6rem 2.5rem; 
    border-radius: 8px; 
    outline: none; 
    opacity: 0;
    transition: all var(--transition-smooth);
}

.search-container:focus-within .search-input,
.search-container.active .search-input {
    border-color: var(--border);
    opacity: 1;
}

.search-container:focus-within .search-input:focus {
    border-color: var(--accent-blue);
}

.sort-select { 
    background-color: var(--bg-surface); 
    border: 1px solid var(--border); 
    color: var(--text-primary); 
    padding: 0.6rem; 
    border-radius: 8px; 
    outline: none; 
    cursor: pointer;
}

/* --- Section Headers --- */
.section-header { 
    display: flex; 
    justify-content: space-between; 
    align-items: center; 
    margin-bottom: 1.25rem; 
}

.section-title { 
    font-size: 1.2rem; 
    font-weight: 700; 
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.view-all-btn { 
    background: none; 
    border: none; 
    color: var(--text-secondary); 
    cursor: pointer; 
    font-size: 0.85rem; 
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 0.25rem;
    transition: color var(--transition-fast);
}

.view-all-btn:hover { 
    color: var(--text-primary); 
}

/* --- Layout Systems (Horizontal Scroll vs Expanded Grid) --- */
.horizontal-scroll { 
    display: flex; 
    gap: 1rem; 
    overflow-x: auto; 
    padding-bottom: 1rem; 
    scroll-snap-type: x mandatory; 
    scrollbar-width: none; /* Firefox */
    -ms-overflow-style: none; /* IE/Edge */
}

.horizontal-scroll::-webkit-scrollbar { 
    display: none; /* Chrome/Safari */
}

.grid-expanded { 
    display: flex; 
    flex-wrap: wrap; 
    gap: 1rem; 
}

/* --- Smart Thumbnail Cards --- */
.card { 
    background-color: var(--bg-surface); 
    border: 1px solid var(--border); 
    border-radius: 12px; 
    width: 200px; 
    flex: 0 0 auto; /* Prevents shrinking in horizontal scroll */
    scroll-snap-align: start; 
    display: flex; 
    flex-direction: column; 
    overflow: hidden; 
    position: relative; 
    transition: transform var(--transition-fast), border-color var(--transition-fast);
}

.card:hover {
    border-color: var(--border-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

/* Responsive Grid Sizing */
.grid-expanded .card { 
    width: calc(50% - 0.5rem); 
    max-width: 220px; 
} 

@media (min-width: 768px) {
    .grid-expanded .card { 
        width: calc(33.333% - 0.67rem); 
    }
}

.card-thumb { 
    height: 140px; 
    width: 100%; 
    position: relative; 
    background-color: var(--bg-elevated);
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Floating Bookmark Button over Thumbnail */
.bookmark-btn { 
    position: absolute; 
    top: 8px; 
    right: 8px; 
    background-color: rgba(0, 0, 0, 0.6); 
    border: 1px solid rgba(255,255,255,0.1); 
    border-radius: 50%; 
    width: 32px; 
    height: 32px; 
    cursor: pointer; 
    backdrop-filter: blur(4px); 
    -webkit-backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
    z-index: 10;
}

.bookmark-btn:hover {
    background-color: rgba(0, 0, 0, 0.8);
    transform: scale(1.1);
}

.card-content { 
    padding: 1rem; 
    flex-grow: 1; 
    display: flex;
    flex-direction: column;
}

.card-title { 
    font-size: 0.95rem; 
    font-weight: 600; 
    margin-bottom: 0.25rem; 
    line-height: 1.3;
    /* Perfect text clamping for long names */
    display: -webkit-box; 
    -webkit-line-clamp: 2; 
    -webkit-box-orient: vertical; 
    overflow: hidden; 
}

.card-meta { 
    font-size: 0.75rem; 
    color: var(--text-secondary); 
    margin-bottom: 0.75rem; 
}

.card-tags { 
    display: flex; 
    gap: 0.35rem; 
    overflow: hidden; 
    margin-top: auto; /* Pushes tags to bottom of content area */
}

.card-tag-pill {
    background-color: var(--bg-elevated);
    color: var(--text-secondary);
    font-size: 0.65rem;
    padding: 0.15rem 0.4rem;
    border-radius: 4px;
    white-space: nowrap;
}

.download-btn { 
    display: flex; 
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    background-color: var(--bg-elevated); 
    padding: 0.75rem; 
    color: var(--text-primary); 
    text-decoration: none; 
    border-top: 1px solid var(--border); 
    font-size: 0.85rem; 
    font-weight: 600;
    transition: background-color var(--transition-fast);
}

.download-btn:hover { 
    background-color: var(--accent-blue); 
}

/* --- A-Z Tags Cloud --- */
.tag-cloud { 
    display: flex; 
    flex-wrap: wrap; 
    gap: 0.5rem; 
}

.tag { 
    background-color: var(--bg-surface); 
    border: 1px solid var(--border); 
    color: var(--text-secondary); 
    padding: 0.4rem 0.8rem; 
    border-radius: 20px; 
    font-size: 0.8rem; 
    cursor: pointer; 
    transition: all var(--transition-fast);
}

.tag:hover, .tag.active { 
    color: var(--text-primary); 
    border-color: var(--accent-blue); 
    background-color: rgba(59, 130, 246, 0.1);
}

/* --- Upload Modal UI --- */
.modal-overlay { 
    position: fixed; 
    inset: 0; 
    background-color: rgba(0, 0, 0, 0.85); 
    backdrop-filter: blur(5px);
    -webkit-backdrop-filter: blur(5px);
    display: none; 
    place-items: center; 
    z-index: 100; 
}

.modal-overlay.active { 
    display: grid; 
    animation: fadeIn 0.2s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: scale(0.95); }
    to { opacity: 1; transform: scale(1); }
}

.modal-content { 
    background-color: var(--bg-surface); 
    padding: 2rem; 
    border-radius: 16px; 
    width: 90%; 
    max-width: 420px; 
    border: 1px solid var(--border); 
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.5);
}

.modal-header { 
    display: flex; 
    justify-content: space-between; 
    align-items: center;
    margin-bottom: 1.5rem; 
}

.close-btn { 
    background: none; 
    border: none; 
    color: var(--text-secondary); 
    font-size: 1.5rem; 
    cursor: pointer; 
    transition: color var(--transition-fast);
}

.close-btn:hover { color: var(--text-primary); }

.dropzone { 
    border: 2px dashed var(--border); 
    padding: 2.5rem 1rem; 
    text-align: center; 
    border-radius: 12px; 
    margin-bottom: 1.5rem; 
    cursor: pointer; 
    background-color: var(--bg-base);
    transition: border-color var(--transition-fast);
}

.dropzone:hover { border-color: var(--accent-blue); }

.form-input { 
    width: 100%; 
    padding: 0.8rem; 
    background-color: var(--bg-base); 
    border: 1px solid var(--border); 
    color: var(--text-primary); 
    border-radius: 8px; 
    margin-bottom: 1.5rem; 
    outline: none;
}

.form-input:focus { border-color: var(--accent-blue); }

.btn-primary { 
    width: 100%; 
    padding: 0.8rem; 
    background-color: var(--accent-blue); 
    border: none; 
    color: var(--text-primary); 
    font-weight: 600; 
    border-radius: 8px; 
    cursor: pointer; 
    transition: background-color var(--transition-fast);
}

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

.btn-primary:disabled {
    background-color: var(--text-secondary);
    cursor: not-allowed;
}

.status-msg { margin-top: 1rem; text-align: center; font-size: 0.9rem; font-weight: 500;}
.status-msg.success { color: var(--accent-green); } 
.status-msg.error { color: #ef4444; }

/* --- Mobile App Bottom Navigation --- */
.bottom-nav { 
    position: fixed; 
    bottom: 0; 
    width: 100%; 
    display: flex; 
    justify-content: space-around; 
    background-color: var(--bg-navbar); 
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-top: 1px solid var(--border); 
    padding: 0.75rem 0; 
    z-index: 50; 
    padding-bottom: calc(0.75rem + env(safe-area-inset-bottom)); /* iOS support */
}

.nav-item { 
    display: flex; 
    flex-direction: column; 
    align-items: center; 
    color: var(--text-secondary); 
    text-decoration: none; 
    font-size: 0.7rem; 
    font-weight: 500;
    gap: 6px; 
    transition: color var(--transition-fast);
}

.nav-item i { font-size: 1.25rem; }
.nav-item.active { color: var(--text-primary); }

.upload-btn { color: var(--accent-blue); } 
.upload-btn i { font-size: 1.75rem; margin-top: -4px; }
/* ==========================================================================
   HERO CAROUSEL SECTION
   ========================================================================== */
.hero-carousel-container {
    position: relative;
    overflow: hidden;
    border-radius: 16px;
    width: 100%;
    background-color: var(--bg-surface);
    border: 1px solid var(--border);
    box-shadow: var(--shadow-md);
}

.hero-carousel {
    display: flex;
    transition: transform 0.6s cubic-bezier(0.25, 1, 0.5, 1);
    width: 100%;
}

.carousel-slide {
    min-width: 100%;
    position: relative;
    height: 250px; /* Mobile height */
    display: flex;
}

@media (min-width: 768px) {
    .carousel-slide { height: 350px; } /* Desktop height */
}

.carousel-bg {
    position: absolute;
    inset: 0;
    background-size: cover;
    background-position: center 20%;
    opacity: 0.5;
    transition: opacity var(--transition-smooth);
}

.carousel-overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(to top, rgba(15,15,19,1) 0%, rgba(15,15,19,0.6) 50%, rgba(15,15,19,0.1) 100%);
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    padding: 2rem;
    z-index: 2;
}

.carousel-title {
    font-size: 1.5rem;
    font-weight: 800;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
    line-height: 1.2;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.carousel-meta {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 1.25rem;
    font-weight: 500;
}

.carousel-indicators {
    position: absolute;
    bottom: 16px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 8px;
    z-index: 3;
}

.indicator {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background-color: rgba(255, 255, 255, 0.3);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.indicator.active {
    background-color: var(--accent-blue);
    width: 24px; /* Expands into a pill shape */
    border-radius: 4px;
}