/* ==========================================
   CSS Design Tokens & Theme Variables
   ========================================== */
:root {
    /* Color Palette - Light Theme (Cream & Terracotta) */
    --bg-primary: #FAF7F2; /* Parchment cream */
    --bg-secondary: #FFFDF9;
    --bg-card: #FFFFFF;
    --text-primary: #2C2620; /* Soft charcoal brown */
    --text-secondary: #6B5E53;
    --accent-color: #D35400; /* Terracotta */
    --accent-hover: #E67E22;
    --border-color: #E6DFD5;
    
    --shadow-sm: 0 2px 4px rgba(44, 38, 32, 0.05);
    --shadow-md: 0 8px 16px rgba(44, 38, 32, 0.08);
    --shadow-lg: 0 16px 32px rgba(44, 38, 32, 0.12);
    
    /* Level Badge Colors */
    --color-lvl-1: #4A90E2;
    --color-lvl-2: #2ECC71;
    --color-lvl-3: #F1C40F;
    --color-lvl-4: #E74C3C;

    /* Interface Settings */
    --font-ui: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    --font-reader: 'Noto Serif Devanagari', Georgia, serif;
    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --transition-speed: 0.3s;
    
    /* Glassmorphism background fallback */
    --glass-bg: rgba(255, 255, 255, 0.8);
    --glass-border: rgba(230, 223, 213, 0.6);
}

body.dark-theme {
    /* Color Palette - Dark Theme (Deep Blue & Slate) */
    --bg-primary: #0F172A; /* Slate 900 */
    --bg-secondary: #1E293B; /* Slate 800 */
    --bg-card: #1E293B;
    --text-primary: #E2E8F0; /* Slate 200 */
    --text-secondary: #94A3B8; /* Slate 400 */
    --accent-color: #F59E0B; /* Warm amber */
    --accent-hover: #FBBF24;
    --border-color: #334155; /* Slate 700 */
    
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 8px 16px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 16px 32px rgba(0, 0, 0, 0.4);
    
    --glass-bg: rgba(30, 41, 59, 0.85);
    --glass-border: rgba(51, 65, 85, 0.5);
}

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

body {
    font-family: var(--font-ui);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.5;
    transition: background-color var(--transition-speed), color var(--transition-speed);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    overflow-x: hidden;
}

/* Scrollbar customizations */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}
::-webkit-scrollbar-track {
    background: var(--bg-primary);
}
::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
    background: var(--text-secondary);
}

/* ==========================================
   App Header & Navigation
   ========================================== */
.app-header {
    background-color: var(--bg-card);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-sm);
    transition: background-color var(--transition-speed), border-color var(--transition-speed);
}

.header-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0.75rem 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo-group {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--accent-color);
    user-select: none;
    transition: transform 0.2s ease;
}

.logo-group:hover {
    transform: scale(1.02);
}

.logo-subtext {
    font-size: 0.9rem;
    font-weight: 400;
    color: var(--text-secondary);
    margin-left: 0.2rem;
}

.logo-icon {
    font-size: 1.5rem;
}

.icon-button {
    background: none;
    border: none;
    cursor: pointer;
    color: var(--text-secondary);
    padding: 0.5rem;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color 0.2s, color 0.2s;
}

.icon-button:hover {
    background-color: var(--border-color);
    color: var(--text-primary);
}

body.light-theme .sun-icon {
    display: none;
}

body.dark-theme .moon-icon {
    display: none;
}

.app-main {
    flex: 1;
    max-width: 1200px;
    width: 100%;
    margin: 0 auto;
    padding: 2rem 1.5rem;
    display: flex;
    flex-direction: column;
}

/* ==========================================
   Dashboard View Component
   ========================================== */
.view-panel {
    display: none;
    opacity: 0;
    transition: opacity 0.3s ease-in-out;
}

.view-panel.active {
    display: block;
    opacity: 1;
}

.dashboard-hero {
    margin-bottom: 2.5rem;
    text-align: center;
}

.dashboard-hero h1 {
    font-family: var(--font-reader);
    font-size: 2.5rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.dashboard-hero p {
    font-size: 1.1rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* Filters */
.level-filters-wrapper {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 2.5rem;
    flex-wrap: wrap;
}

.filter-label {
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.level-filters {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.filter-pill {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 0.5rem 1rem;
    border-radius: var(--radius-lg);
    font-weight: 500;
    font-size: 0.9rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.4rem;
    box-shadow: var(--shadow-sm);
    transition: all 0.2s ease;
}

.filter-pill:hover {
    border-color: var(--accent-color);
    transform: translateY(-1px);
}

.filter-pill.active {
    background-color: var(--accent-color);
    border-color: var(--accent-color);
    color: #FFFFFF;
}

.pill-badge {
    font-size: 0.75rem;
    font-weight: 700;
    padding: 0.1rem 0.4rem;
    border-radius: 4px;
    color: #FFFFFF;
}

.pill-badge.lvl-1 { background-color: var(--color-lvl-1); }
.pill-badge.lvl-2 { background-color: var(--color-lvl-2); }
.pill-badge.lvl-3 { background-color: var(--color-lvl-3); }
.pill-badge.lvl-4 { background-color: var(--color-lvl-4); }

.filter-pill.active .pill-badge {
    background-color: rgba(255, 255, 255, 0.25);
}

/* Story Card Grid */
.story-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 2rem;
}

.story-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    box-shadow: var(--shadow-sm);
    cursor: pointer;
    transition: transform var(--transition-speed) cubic-bezier(0.165, 0.84, 0.44, 1),
                box-shadow var(--transition-speed) ease;
}

.story-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-lg);
}

.card-cover {
    height: 140px;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    padding: 1.5rem;
    color: #FFFFFF;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

.card-level-badge {
    position: absolute;
    top: 0.75rem;
    right: 0.75rem;
    background-color: rgba(0, 0, 0, 0.4);
    color: #FFFFFF;
    font-size: 0.75rem;
    font-weight: 700;
    padding: 0.2rem 0.5rem;
    border-radius: 4px;
    backdrop-filter: blur(4px);
}

.card-cover-title {
    font-family: var(--font-reader);
    font-size: 1.8rem;
    text-align: center;
    font-weight: 700;
}

.card-body {
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    flex: 1;
}

.card-title-latin {
    font-size: 0.85rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.5rem;
}

.card-title-hindi {
    font-family: var(--font-reader);
    font-size: 1.4rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
    line-height: 1.2;
}

.card-synopsis {
    font-size: 0.9rem;
    color: var(--text-secondary);
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
    margin-bottom: 1.5rem;
    flex: 1;
}

.card-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-top: 1px solid var(--border-color);
    padding-top: 1rem;
    font-size: 0.85rem;
    font-weight: 500;
}

.level-text {
    color: var(--text-secondary);
}

.level-text.lvl-1 { color: var(--color-lvl-1); }
.level-text.lvl-2 { color: var(--color-lvl-2); }
.level-text.lvl-3 { color: var(--color-lvl-3); }
.level-text.lvl-4 { color: var(--color-lvl-4); }

.read-action-link {
    color: var(--accent-color);
    display: flex;
    align-items: center;
    gap: 0.2rem;
    font-weight: 600;
}

/* ==========================================
   Reader View Component
   ========================================== */
.reader-header {
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
    gap: 1.5rem;
    background-color: var(--bg-card);
    padding: 0.75rem 1rem;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
}

.text-button {
    background: none;
    border: none;
    cursor: pointer;
    font-weight: 600;
    font-size: 0.95rem;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.5rem 0.8rem;
    border-radius: var(--radius-sm);
    transition: background-color 0.2s;
}

.text-button:hover {
    background-color: var(--border-color);
}

.story-progress-container {
    flex: 1;
    max-width: 500px;
    display: flex;
    flex-direction: column;
    gap: 0.3rem;
    text-align: center;
}

.story-display-title {
    font-family: var(--font-reader);
    font-size: 1.05rem;
    font-weight: 600;
    line-height: 1.3;
}

.progress-bar-bg {
    height: 6px;
    background-color: var(--border-color);
    border-radius: 3px;
    overflow: hidden;
}

.progress-bar-fill {
    height: 100%;
    width: 25%;
    background-color: var(--accent-color);
    border-radius: 3px;
    transition: width 0.3s cubic-bezier(0.165, 0.84, 0.44, 1);
}

/* Center-Aligned Book Structure */
.book-container {
    display: flex;
    flex-direction: column;
    max-width: 800px;
    margin: 0 auto;
    width: 100%;
    flex: 1;
}

/* Right panel - Reading canvas */
.reading-panel {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    padding: 2.5rem;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    transition: background-color var(--transition-speed);
    min-height: 400px;
}

.reading-canvas-inner {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

/* ==========================================
   Story Text & Sentence Layouts
   ========================================== */
.story-text-container {
    margin-bottom: 2rem;
}

.story-sentence {
    position: relative;
    margin-bottom: 1.5rem;
    padding: 0.5rem 0.75rem;
    border-radius: var(--radius-sm);
    border-left: 3px solid transparent;
    cursor: pointer;
    transition: all 0.2s ease;
}

/* Sentence Hover & Selection Highlights */
.story-sentence:hover {
    background-color: rgba(211, 84, 0, 0.03);
    border-left-color: rgba(211, 84, 0, 0.3);
}

body.dark-theme .story-sentence:hover {
    background-color: rgba(245, 158, 11, 0.05);
    border-left-color: rgba(245, 158, 11, 0.3);
}

.story-sentence.active-sentence {
    background-color: rgba(211, 84, 0, 0.06);
    border-left-color: var(--accent-color);
}

body.dark-theme .story-sentence.active-sentence {
    background-color: rgba(245, 158, 11, 0.08);
    border-left-color: var(--accent-color);
}

/* Word Token Styles */
.word-token {
    font-family: var(--font-reader);
    display: inline-block;
    cursor: pointer;
    padding: 0.15rem 0.25rem;
    margin: 0 0.05rem;
    border-radius: 4px;
    border-bottom: 1px dotted var(--text-secondary);
    transition: all 0.2s ease;
}

.word-token:hover {
    background-color: rgba(211, 84, 0, 0.12);
    color: var(--accent-color);
    border-bottom-color: transparent;
    transform: translateY(-1px);
}

body.dark-theme .word-token:hover {
    background-color: rgba(245, 158, 11, 0.2);
    color: var(--accent-color);
    border-bottom-color: transparent;
}

.word-token.selected-token {
    background-color: var(--accent-color);
    color: #FFFFFF !important;
    border-bottom-color: transparent;
    box-shadow: 0 2px 4px rgba(211, 84, 0, 0.2);
}

/* Whitespace & Sizing based on Story levels */
.level-1-text { font-size: 2.2rem; line-height: 2.4; }
.level-2-text { font-size: 1.9rem; line-height: 2.1; }
.level-3-text { font-size: 1.6rem; line-height: 1.8; }
.level-4-text { font-size: 1.4rem; line-height: 1.6; }

/* Plain text (punctuation/spaces) */
.plain-text {
    font-family: var(--font-reader);
    font-size: inherit;
    line-height: inherit;
    color: var(--text-primary);
}

/* ==========================================
   Sentence Translation Assistant
   ========================================== */
.sentence-assistant {
    border-top: 1px dashed var(--border-color);
    padding-top: 1.5rem;
    margin-top: 1rem;
    min-height: 80px;
}

.sentence-action-btn {
    background: none;
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    padding: 0.5rem 1rem;
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: all 0.2s;
}

.sentence-action-btn:hover {
    border-color: var(--accent-color);
    color: var(--accent-color);
    background-color: rgba(211, 84, 0, 0.02);
}

body.dark-theme .sentence-action-btn:hover {
    background-color: rgba(245, 158, 11, 0.04);
}

.sentence-translation-text {
    font-size: 1.1rem;
    font-style: italic;
    color: var(--text-secondary);
    line-height: 1.6;
    animation: fadeInSlide 0.2s ease-out;
}

.sentence-translation-text.hidden {
    display: none;
}

/* ==========================================
   Book Navigation Controls
   ========================================== */
.book-controls {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-top: 2rem;
    border-top: 1px solid var(--border-color);
    padding-top: 1.5rem;
}

.control-btn {
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    width: 44px;
    height: 44px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    box-shadow: var(--shadow-sm);
    transition: all 0.2s ease;
}

.control-btn:hover:not(:disabled) {
    border-color: var(--accent-color);
    color: var(--accent-color);
    transform: scale(1.05);
}

.control-btn:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.page-number-text {
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--text-secondary);
    letter-spacing: 0.02em;
}

/* ==========================================
   Interactive Floating Tooltip Component
   ========================================== */
.word-tooltip-card {
    position: absolute;
    z-index: 1000;
    background-color: var(--glass-bg);
    border: 1px solid var(--glass-border);
    backdrop-filter: blur(12px) saturate(180%);
    -webkit-backdrop-filter: blur(12px) saturate(180%);
    border-radius: var(--radius-md);
    padding: 1rem 1.25rem;
    width: 250px;
    box-shadow: var(--shadow-lg);
    display: flex;
    flex-direction: column;
    gap: 0.6rem;
    opacity: 0;
    transform: translateY(10px) scale(0.95);
    pointer-events: none;
    transition: opacity 0.2s ease, transform 0.2s ease;
}

.word-tooltip-card.visible {
    opacity: 1;
    transform: translateY(0) scale(1);
    pointer-events: auto;
}

.word-tooltip-card.hidden {
    display: none;
}

/* Tooltip Arrow */
.tooltip-arrow {
    position: absolute;
    width: 12px;
    height: 12px;
    background-color: var(--glass-bg);
    transform: rotate(45deg);
    z-index: -1;
}

/* Arrow orientation stylings */
.word-tooltip-card.arrow-bottom .tooltip-arrow {
    bottom: -6px;
    left: calc(50% - 6px);
    border-right: 1px solid var(--glass-border);
    border-bottom: 1px solid var(--glass-border);
}

.word-tooltip-card.arrow-top .tooltip-arrow {
    top: -6px;
    left: calc(50% - 6px);
    border-left: 1px solid var(--glass-border);
    border-top: 1px solid var(--glass-border);
}

.tooltip-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.5rem;
}

.word-info {
    display: flex;
    flex-direction: column;
    gap: 0.1rem;
}

.word-info h3 {
    font-family: var(--font-reader);
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--accent-color);
    line-height: 1.1;
}

.word-info span {
    font-size: 0.85rem;
    color: var(--text-secondary);
    font-style: italic;
}

.icon-button.mini {
    padding: 0.35rem;
    background-color: var(--border-color);
}

.icon-button.mini:hover {
    background-color: var(--accent-color);
    color: #FFFFFF;
}

.tooltip-body {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.word-meaning {
    font-size: 1.05rem;
    font-weight: 500;
    color: var(--text-primary);
    line-height: 1.4;
}

.word-meta {
    display: flex;
    gap: 0.4rem;
    flex-wrap: wrap;
}

.meta-tag {
    font-size: 0.75rem;
    font-weight: 600;
    padding: 0.15rem 0.5rem;
    border-radius: 4px;
    text-transform: uppercase;
    letter-spacing: 0.02em;
}

.meta-tag.pos {
    background-color: var(--border-color);
    color: var(--text-secondary);
}

.meta-tag.gender {
    background-color: rgba(211, 84, 0, 0.08);
    color: var(--accent-color);
}

body.dark-theme .meta-tag.gender {
    background-color: rgba(245, 158, 11, 0.12);
    color: var(--accent-color);
}

/* ==========================================
   Page Flip Transition & Keyframes
   ========================================== */
.fade-transition {
    animation: fadeInSlide 0.3s cubic-bezier(0.165, 0.84, 0.44, 1) forwards;
}

@keyframes fadeInSlide {
    from {
        opacity: 0;
        transform: translateY(8px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* SVG Illustrations Generator Classes */
.ill-svg {
    width: 100%;
    height: 100%;
    display: block;
}

/* Story Attribution Container */
.story-attribution-container {
    margin-top: 3rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
    text-align: center;
}

.story-attribution-text {
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.4;
    font-style: italic;
}

/* ==========================================
   Responsive Breakpoints
   ========================================== */
@media (max-width: 860px) {
    .reading-panel {
        padding: 1.5rem;
        min-height: auto;
    }
    
    .dashboard-hero h1 {
        font-size: 2rem;
    }
}

@media (max-width: 480px) {
    .app-main {
        padding: 1rem 0.75rem;
    }
    
    .level-filters-wrapper {
        margin-bottom: 1.5rem;
    }
    
    .story-grid {
        grid-template-columns: 1fr;
    }
    
    .level-filters {
        justify-content: center;
    }
    
    .level-1-text { font-size: 1.8rem; }
    .level-2-text { font-size: 1.6rem; }
    .level-3-text { font-size: 1.4rem; }
    .level-4-text { font-size: 1.25rem; }
}