/* Import premium Google Fonts */
@import url('https://fonts.googleapis.com/css2?family=Fira+Code:wght@400;500;700&family=Outfit:wght@300;400;500;600;700;800&display=swap');

:root {
    /* Color Palette - Vibrant Chemistry Theme */
    --bg-dark: #0b0f19;
    --bg-card: rgba(17, 24, 39, 0.7);
    --bg-card-hover: rgba(31, 41, 55, 0.8);
    --border-color: rgba(255, 255, 255, 0.08);
    
    /* Neon accents for each unit */
    --accent-u1: #00f2fe; /* Water: Cyan */
    --accent-u2: #ff6a00; /* Fuels: Fire Orange */
    --accent-u3: #38ef7d; /* Battery: Cobalt Green */
    --accent-u4: #ec008c; /* Polymers: Magenta/Violet */
    --accent-mixed: #a18cd1; /* Mixed: Lavender */
    --accent-exam: #ff007f; /* Exam: Hot Pink */
    
    --text-primary: #f3f4f6;
    --text-secondary: #9ca3af;
    --text-muted: #6b7280;
    
    --shadow-neon-u1: 0 0 20px rgba(0, 242, 254, 0.15);
    --shadow-neon-u2: 0 0 20px rgba(255, 106, 0, 0.15);
    --shadow-neon-u3: 0 0 20px rgba(56, 239, 125, 0.15);
    --shadow-neon-u4: 0 0 20px rgba(236, 0, 140, 0.15);
    
    --glass-bg: rgba(17, 25, 40, 0.65);
    --glass-border: rgba(255, 255, 255, 0.07);
    
    --transition-smooth: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.light-theme {
    --bg-dark: #f0f2f5;
    --bg-card: rgba(255, 255, 255, 0.85);
    --bg-card-hover: rgba(255, 255, 255, 0.95);
    --border-color: rgba(0, 0, 0, 0.08);
    --text-primary: #111827;
    --text-secondary: #4b5563;
    --text-muted: #9ca3af;
    --glass-bg: rgba(255, 255, 255, 0.7);
    --glass-border: rgba(0, 0, 0, 0.07);
}

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

body {
    background-color: var(--bg-dark);
    color: var(--text-primary);
    font-family: 'Outfit', sans-serif;
    min-height: 100vh;
    display: flex;
    overflow-x: hidden;
    transition: var(--transition-smooth);
}

/* Scrollbar Styling */
::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}
::-webkit-scrollbar-track {
    background: var(--bg-dark);
}
::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.15);
    border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.3);
}

/* Sidebar Styling */
aside {
    width: 300px;
    background: var(--glass-bg);
    backdrop-filter: blur(16px);
    border-right: 1px solid var(--glass-border);
    display: flex;
    flex-direction: column;
    height: 100vh;
    position: fixed;
    left: 0;
    top: 0;
    z-index: 100;
    transition: var(--transition-smooth);
}

.sidebar-header {
    padding: 24px;
    border-bottom: 1px solid var(--border-color);
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-weight: 800;
    font-size: 1.35rem;
    letter-spacing: 0.5px;
    background: linear-gradient(135deg, #00f2fe, #ff007f);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.logo-icon {
    font-size: 1.8rem;
    animation: rotateAtom 6s linear infinite;
}

@keyframes rotateAtom {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.sidebar-menu {
    flex: 1;
    overflow-y: auto;
    padding: 16px;
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.menu-section-label {
    font-size: 0.72rem;
    font-weight: 700;
    text-transform: uppercase;
    color: var(--text-muted);
    padding: 12px 10px 4px 10px;
    letter-spacing: 1.5px;
}

.menu-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 14px;
    border-radius: 8px;
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.92rem;
    cursor: pointer;
    transition: var(--transition-smooth);
    border: 1px solid transparent;
}

.menu-item:hover {
    background: rgba(255, 255, 255, 0.03);
    color: var(--text-primary);
}

.menu-item.active {
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-primary);
    border-left: 4px solid var(--accent-theme, #00f2fe);
    font-weight: 600;
}

.theme-toggle-container {
    padding: 16px 24px;
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.theme-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    font-size: 1.15rem;
    padding: 6px;
    border-radius: 50%;
    transition: var(--transition-smooth);
}

.theme-btn:hover {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.05);
}

/* Main Content Area */
main {
    margin-left: 300px;
    flex: 1;
    min-height: 100vh;
    padding: 30px;
    display: flex;
    flex-direction: column;
    gap: 24px;
    max-width: 1300px;
}

/* Top Bar Styling */
.top-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 20px;
    z-index: 50;
}

.search-box {
    position: relative;
    width: 350px;
}

.search-box input {
    width: 100%;
    padding: 12px 16px 12px 40px;
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 10px;
    color: var(--text-primary);
    font-family: inherit;
    font-size: 0.9rem;
    transition: var(--transition-smooth);
}

.search-box input:focus {
    outline: none;
    border-color: #00f2fe;
    box-shadow: 0 0 10px rgba(0, 242, 254, 0.1);
}

.search-box i {
    position: absolute;
    left: 14px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-muted);
}

.quick-stats {
    display: flex;
    gap: 16px;
}

.stat-chip {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 14px;
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
}

.stat-chip.exam-countdown {
    background: rgba(255, 0, 127, 0.1);
    border-color: rgba(255, 0, 127, 0.2);
    color: #ff55a3;
}

/* Dashboard Home view */
.welcome-banner {
    background: linear-gradient(135deg, rgba(0, 242, 254, 0.1) 0%, rgba(236, 0, 140, 0.1) 100%);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    padding: 40px;
    position: relative;
    overflow: hidden;
}

.welcome-banner::after {
    content: '';
    position: absolute;
    right: -100px;
    bottom: -100px;
    width: 300px;
    height: 300px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(0, 242, 254, 0.1) 0%, transparent 70%);
}

.welcome-banner h1 {
    font-size: 2.2rem;
    font-weight: 800;
    margin-bottom: 12px;
    background: linear-gradient(90deg, #00f2fe, #ff007f);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.welcome-banner p {
    color: var(--text-secondary);
    font-size: 1.05rem;
    max-width: 700px;
    line-height: 1.6;
}

.welcome-stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
    margin-top: 24px;
}

.welcome-stat-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    padding: 20px;
    border-radius: 12px;
    display: flex;
    flex-direction: column;
    gap: 8px;
    transition: var(--transition-smooth);
}

.welcome-stat-card:hover {
    transform: translateY(-2px);
    border-color: var(--u-color, #00f2fe);
}

.welcome-stat-card h3 {
    font-size: 0.85rem;
    color: var(--text-secondary);
    font-weight: 600;
}

.welcome-stat-card .val {
    font-size: 1.8rem;
    font-weight: 800;
    color: var(--text-primary);
}

.welcome-stat-card .desc {
    font-size: 0.75rem;
    color: var(--text-muted);
}

/* Tab Layout Inside Content views */
.view-container {
    display: none;
    flex-direction: column;
    gap: 24px;
    animation: fadeIn 0.4s ease;
}

.view-container.active {
    display: flex;
}

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

.view-header {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.view-header h2 {
    font-size: 1.8rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 12px;
}

.view-header p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.tab-nav {
    display: flex;
    border-bottom: 1px solid var(--border-color);
    gap: 8px;
    padding-bottom: 2px;
}

.tab-btn {
    background: none;
    border: none;
    padding: 12px 20px;
    color: var(--text-secondary);
    font-family: inherit;
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    border-radius: 8px 8px 0 0;
    position: relative;
    transition: var(--transition-smooth);
}

.tab-btn:hover {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.02);
}

.tab-btn.active {
    color: var(--u-color, #00f2fe);
}

.tab-btn.active::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    right: 0;
    height: 3px;
    background-color: var(--u-color, #00f2fe);
    border-radius: 2px;
}

.tab-content {
    display: none;
    flex-direction: column;
    gap: 20px;
}

.tab-content.active {
    display: flex;
}

/* Card layout inside Tabs */
.grid-2 {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
}

.grid-3 {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 24px;
    display: flex;
    flex-direction: column;
    gap: 16px;
    transition: var(--transition-smooth);
    position: relative;
    overflow: hidden;
}

.card:hover {
    background: var(--bg-card-hover);
    border-color: var(--card-accent, rgba(255, 255, 255, 0.15));
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 12px;
}

.card-title {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--text-primary);
}

.tag {
    font-size: 0.72rem;
    font-weight: 700;
    padding: 4px 8px;
    border-radius: 4px;
    text-transform: uppercase;
}

.tag.high-prob {
    background: rgba(255, 0, 127, 0.15);
    color: #ff3399;
    border: 1px solid rgba(255, 0, 127, 0.3);
}

.tag.common {
    background: rgba(255, 106, 0, 0.15);
    color: #ff7733;
    border: 1px solid rgba(255, 106, 0, 0.3);
}

.tag.ml-qp {
    background: rgba(56, 239, 125, 0.15);
    color: #39ec7d;
    border: 1px solid rgba(56, 239, 125, 0.3);
}

.card-body {
    font-size: 0.92rem;
    line-height: 1.6;
    color: var(--text-secondary);
}

/* Accordion list details (for Question Bank & Assignment Answers) */
.accordion {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.acc-item {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    overflow: hidden;
    transition: var(--transition-smooth);
}

.acc-item:hover {
    border-color: var(--u-color, rgba(255, 255, 255, 0.15));
}

.acc-header {
    padding: 18px 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    user-select: none;
    font-weight: 600;
    font-size: 0.95rem;
    transition: var(--transition-smooth);
}

.acc-header:hover {
    background: rgba(255, 255, 255, 0.01);
}

.acc-title-area {
    display: flex;
    align-items: center;
    gap: 12px;
}

.acc-icon {
    font-size: 0.85rem;
    color: var(--text-muted);
    transition: transform 0.3s ease;
}

.acc-item.expanded .acc-icon {
    transform: rotate(90deg);
    color: var(--u-color, #00f2fe);
}

.acc-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out, padding 0.3s ease;
    background: rgba(0, 0, 0, 0.15);
    border-top: 1px solid transparent;
}

.acc-item.expanded .acc-content {
    max-height: 1500px; /* high value for content */
    padding: 24px;
    border-top-color: var(--border-color);
}

.solution-badge {
    background: rgba(255, 255, 255, 0.05);
    padding: 2px 8px;
    border-radius: 4px;
    font-size: 0.72rem;
    color: var(--text-secondary);
    font-weight: 600;
    display: inline-block;
    margin-bottom: 12px;
}

.solution-details {
    font-size: 0.95rem;
    line-height: 1.7;
    color: var(--text-secondary);
    display: flex;
    flex-direction: column;
    gap: 14px;
}

.solution-details blockquote {
    border-left: 4px solid var(--u-color, #00f2fe);
    padding: 10px 16px;
    background: rgba(255, 255, 255, 0.01);
    border-radius: 0 8px 8px 0;
    font-style: italic;
    color: var(--text-primary);
}

/* Master Checkbox */
.master-chk {
    display: flex;
    align-items: center;
    gap: 10px;
    cursor: pointer;
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-muted);
    margin-top: 16px;
}

.master-chk input {
    cursor: pointer;
    width: 14px;
    height: 14px;
    accent-color: var(--u-color, #00f2fe);
}

/* Numerical Interactive Solvers */
.solver-container {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 24px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
    position: relative;
    overflow: hidden;
}

.solver-container::after {
    content: '';
    position: absolute;
    right: 0;
    top: 0;
    width: 6px;
    height: 100%;
    background: var(--u-color, #00f2fe);
}

.solver-inputs {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.solver-group {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.solver-group label {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-secondary);
}

.solver-group input, .solver-group select {
    padding: 10px 14px;
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-primary);
    font-family: inherit;
    font-size: 0.9rem;
    transition: var(--transition-smooth);
}

.solver-group input:focus, .solver-group select:focus {
    outline: none;
    border-color: var(--u-color, #00f2fe);
}

.solver-output {
    background: rgba(0, 0, 0, 0.2);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.solver-output-title {
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--u-color, #00f2fe);
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 10px;
}

.formula-display {
    font-family: 'Fira Code', monospace;
    font-size: 0.9rem;
    color: #e5e7eb;
    padding: 10px;
    background: rgba(255, 255, 255, 0.02);
    border-radius: 6px;
    border-left: 3px solid var(--text-muted);
}

.steps-display {
    font-size: 0.85rem;
    color: var(--text-secondary);
    display: flex;
    flex-direction: column;
    gap: 10px;
    max-height: 250px;
    overflow-y: auto;
}

.step-row {
    border-bottom: 1px dashed rgba(255, 255, 255, 0.05);
    padding-bottom: 8px;
}

.step-row:last-child {
    border-bottom: none;
    padding-bottom: 0;
}

.result-row {
    font-size: 1.1rem;
    font-weight: 800;
    color: #38ef7d;
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 10px;
}

/* Exam Hub */
.exam-header-meta {
    background: rgba(255, 0, 127, 0.05);
    border: 1px solid rgba(255, 0, 127, 0.15);
    padding: 16px 20px;
    border-radius: 8px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 12px;
}

.exam-meta-item {
    font-size: 0.85rem;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 8px;
}

.exam-meta-item strong {
    color: var(--text-primary);
}

.exam-part-label {
    font-size: 1.15rem;
    font-weight: 800;
    color: #ff007f;
    margin-top: 16px;
    padding-bottom: 6px;
    border-bottom: 2px solid rgba(255, 0, 127, 0.2);
}

.exam-question-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.exam-q-text {
    font-weight: 600;
    font-size: 0.98rem;
    color: var(--text-primary);
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
}

.exam-q-marks {
    font-size: 0.8rem;
    color: #ff007f;
    font-weight: 700;
    background: rgba(255, 0, 127, 0.1);
    padding: 2px 8px;
    border-radius: 4px;
}

.exam-q-sol-btn {
    align-self: flex-start;
    background: none;
    border: 1px solid rgba(255, 255, 255, 0.15);
    color: var(--text-secondary);
    padding: 6px 12px;
    border-radius: 6px;
    font-size: 0.8rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition-smooth);
}

.exam-q-sol-btn:hover {
    background: rgba(255, 0, 127, 0.1);
    border-color: rgba(255, 0, 127, 0.3);
    color: #ff007f;
}

.exam-q-sol {
    display: none;
    background: rgba(0, 0, 0, 0.2);
    border-top: 1px solid var(--border-color);
    padding: 16px;
    border-radius: 0 0 8px 8px;
    font-size: 0.95rem;
    line-height: 1.6;
    color: var(--text-secondary);
    margin-top: 10px;
}

.exam-q-sol.active {
    display: block;
}

/* Mixed Unit Flashcards */
.flashcard-arena {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 20px;
    padding: 20px;
}

.flashcard {
    perspective: 1000px;
    width: 100%;
    max-width: 500px;
    height: 280px;
    cursor: pointer;
}

.flashcard-inner {
    position: relative;
    width: 100%;
    height: 100%;
    text-align: center;
    transition: transform 0.6s;
    transform-style: preserve-3d;
}

.flashcard.flipped .flashcard-inner {
    transform: rotateY(180deg);
}

.flashcard-front, .flashcard-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    border-radius: 16px;
    border: 1px solid var(--glass-border);
    padding: 30px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 16px;
}

.flashcard-front {
    background: linear-gradient(135deg, rgba(161, 140, 209, 0.2) 0%, rgba(251, 194, 235, 0.2) 100%);
    color: var(--text-primary);
}

.flashcard-back {
    background: var(--bg-card-hover);
    color: var(--text-primary);
    transform: rotateY(180deg);
}

.flashcard h3 {
    font-size: 1.25rem;
    font-weight: 700;
}

.flashcard p {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

.flashcard-nav {
    display: flex;
    gap: 16px;
}

.f-btn {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    color: var(--text-primary);
    padding: 8px 16px;
    border-radius: 20px;
    cursor: pointer;
    font-size: 0.85rem;
    font-weight: 600;
    transition: var(--transition-smooth);
}

.f-btn:hover {
    background: rgba(255, 255, 255, 0.05);
}

/* Mixed Unit Integrated Guide list */
.guide-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.guide-item {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 24px;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.guide-item h3 {
    font-size: 1.15rem;
    color: #a18cd1;
    font-weight: 700;
}

/* Chemical structures code visual tags */
code {
    font-family: 'Fira Code', monospace;
    background: rgba(255, 255, 255, 0.05);
    padding: 2px 6px;
    border-radius: 4px;
    font-size: 0.85rem;
    color: #ff55a3;
}

sub {
    font-size: 0.75em;
    line-height: 0;
    position: relative;
    vertical-align: baseline;
    bottom: -0.25em;
}

sup {
    font-size: 0.75em;
    line-height: 0;
    position: relative;
    vertical-align: baseline;
    top: -0.5em;
}

/* Slide Culmination Styles */
.culmination-header {
    background: linear-gradient(90deg, rgba(0, 242, 254, 0.05), rgba(236, 0, 140, 0.05));
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 16px 20px;
    margin-bottom: 20px;
}
.culmination-header h3 {
    margin-bottom: 4px;
    font-size: 1.15rem;
    font-weight: 700;
}
.culmination-header p {
    color: var(--text-secondary);
    font-size: 0.85rem;
}
.slides-culmination-list {
    display: flex;
    flex-direction: column;
    gap: 32px;
    max-height: 85vh;
    overflow-y: auto;
    padding-right: 15px;
    border: 1px solid var(--border-color);
    border-radius: 12px;
    background: rgba(0, 0, 0, 0.3);
    padding: 30px;
}
.slide-card-view {
    background: linear-gradient(135deg, #1e293b 0%, #0f172a 100%);
    border: 3px solid var(--border-color);
    border-radius: 16px;
    aspect-ratio: 16 / 9;
    width: 100%;
    max-width: 900px;
    margin: 0 auto;
    padding: 36px 48px;
    position: relative;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    transition: var(--transition-smooth);
    color: #f1f5f9;
}
.slide-card-view:hover {
    border-color: var(--accent-primary, #00f2fe);
    box-shadow: 0 0 35px rgba(0, 242, 254, 0.25);
}
.slide-card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 2px solid rgba(255, 255, 255, 0.1);
    padding-bottom: 14px;
    margin-bottom: 0;
}
.slide-badge {
    background: var(--accent-primary, #00f2fe);
    color: #0f172a;
    font-size: 0.75rem;
    font-weight: 800;
    padding: 4px 12px;
    border-radius: 4px;
    text-transform: uppercase;
    letter-spacing: 1px;
}
.slide-card-header h4 {
    font-size: 1.45rem;
    font-weight: 800;
    color: #ffffff;
    text-shadow: 0 2px 4px rgba(0,0,0,0.4);
    text-align: right;
}
.slide-card-body {
    display: flex;
    flex-direction: column;
    gap: 12px;
    flex-grow: 1;
    justify-content: center;
    padding: 24px 0;
}
.slide-card-body .bullet-item {
    display: flex;
    gap: 12px;
    align-items: flex-start;
    font-size: 1.1rem;
    line-height: 1.6;
}
.slide-card-body .bullet-item i {
    color: var(--accent-primary, #00f2fe);
    margin-top: 6px;
    font-size: 0.8rem;
}
.slide-card-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    padding-top: 12px;
    font-size: 0.8rem;
    color: #94a3b8;
}
.slide-card-footer-left {
    display: flex;
    align-items: center;
    gap: 8px;
}
.slide-card-footer-left i {
    color: var(--accent-primary, #00f2fe);
}
.slide-card-footer-right {
    font-weight: 700;
    letter-spacing: 0.5px;
}

/* Sub-Tab Navigation for Q&A */
.sub-tab-nav {
    display: flex;
    gap: 10px;
    margin-bottom: 16px;
    background: rgba(255,255,255,0.03);
    padding: 6px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
}
.sub-tab-btn {
    background: none;
    border: none;
    padding: 8px 16px;
    font-family: inherit;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-secondary);
    border-radius: 6px;
    cursor: pointer;
    transition: var(--transition-smooth);
}
.sub-tab-btn:hover {
    color: var(--text-primary);
    background: rgba(255,255,255,0.05);
}
.sub-tab-btn.active {
    background: var(--accent-primary, #00f2fe);
    color: #0b0f19;
}

/* Keywords Tags Bar */
.keywords-bar {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-bottom: 12px;
}
.keyword-tag {
    font-size: 0.65rem;
    font-weight: 700;
    background: rgba(255,255,255,0.05);
    color: var(--text-secondary);
    padding: 2px 6px;
    border-radius: 4px;
    border: 1px solid var(--border-color);
}

/* Responsive Rules */
@media(max-width: 1024px) {
    aside {
        width: 80px;
        padding: 10px;
    }
    aside .logo-text, aside .menu-item span, aside .menu-section-label, aside .theme-toggle-container span {
        display: none;
    }
    .theme-toggle-container {
        padding: 16px 0;
        justify-content: center;
    }
    main {
        margin-left: 80px;
        padding: 20px;
    }
    .welcome-stats, .grid-2, .grid-3 {
        grid-template-columns: 1fr;
    }
    .solver-container {
        grid-template-columns: 1fr;
    }
}

/* Widescreen Slide Lightbox Modal */
.slide-lightbox {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(10, 15, 30, 0.95);
    backdrop-filter: blur(12px);
    z-index: 10000;
    display: none;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity 0.3s ease;
}
.slide-lightbox.active {
    display: flex;
    opacity: 1;
}
.lightbox-content-container {
    position: relative;
    width: 90%;
    max-width: 1400px;
    height: 80%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}
.lightbox-img-wrapper {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: auto;
    border-radius: 16px;
    background: #000;
    border: 2px solid var(--border-color);
}
.lightbox-img {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
    transition: transform 0.2s ease;
    transform-origin: center center;
}
.lightbox-close-btn {
    position: absolute;
    top: -50px;
    right: 0;
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid var(--border-color);
    color: #fff;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    font-size: 1.2rem;
    transition: all 0.2s ease;
}
.lightbox-close-btn:hover {
    background: #ef4444;
    border-color: #ef4444;
    transform: rotate(90deg);
}
.lightbox-controls {
    position: absolute;
    bottom: -60px;
    display: flex;
    gap: 16px;
    align-items: center;
}
.lightbox-btn {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid var(--border-color);
    color: #fff;
    padding: 8px 16px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: all 0.2s ease;
}
.lightbox-btn:hover {
    background: var(--accent-primary, #00f2fe);
    color: #0b0f19;
    border-color: var(--accent-primary, #00f2fe);
}
.lightbox-nav-btn {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid var(--border-color);
    color: #fff;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    font-size: 1.5rem;
    transition: all 0.2s ease;
    z-index: 10;
}
.lightbox-nav-btn:hover {
    background: var(--accent-primary, #00f2fe);
    color: #0b0f19;
    border-color: var(--accent-primary, #00f2fe);
}
.lightbox-prev {
    left: -70px;
}
.lightbox-next {
    right: -70px;
}
/* Slide card adjustments for larger visibility */
.slide-card-view {
    cursor: zoom-in;
    max-width: 1100px !important;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}
.slide-card-view:hover {
    transform: scale(1.02);
}
.slides-culmination-list {
    display: block !important;
}
.slide-card-view.image-slide {
    width: 100% !important;
    max-width: 1100px !important;
    margin: 0 auto 32px auto !important;
    padding: 0 !important;
    background: #000 !important;
    border: 3px solid var(--border-color) !important;
    border-radius: 12px !important;
    overflow: visible !important;
    display: block !important;
    aspect-ratio: unset !important;
    height: auto !important;
    box-shadow: 0 12px 36px rgba(0, 0, 0, 0.6) !important;
}
.slide-card-view.image-slide img {
    display: block !important;
    width: 100% !important;
    height: auto !important;
    position: static !important;
}

/* Mobile responsive styles for the Lightbox and Slide Viewer */
@media (max-width: 768px) {
    .slide-card-view {
        border-radius: 8px !important;
        border-width: 2px !important;
    }
    .slides-culmination-list {
        padding: 10px !important;
        gap: 16px !important;
    }
    .lightbox-content-container {
        width: 95% !important;
        height: 60% !important;
    }
    .lightbox-nav-btn {
        width: 44px !important;
        height: 44px !important;
        font-size: 1.1rem !important;
        top: auto !important;
        bottom: -55px !important;
        transform: none !important;
    }
    .lightbox-prev {
        left: 15px !important;
    }
    .lightbox-next {
        right: 15px !important;
    }
    .lightbox-controls {
        bottom: -115px !important;
        gap: 8px !important;
        width: 100%;
        justify-content: center;
    }
    .lightbox-btn {
        padding: 8px 12px !important;
        font-size: 0.8rem !important;
    }
    .lightbox-close-btn {
        top: -45px !important;
        right: 15px !important;
        width: 36px !important;
        height: 36px !important;
        font-size: 1rem !important;
    }
}