:root {
    /* Colors - Group 1 (Light/Vibrant) */
    --bg-primary: #f0f4f8;
    --text-main: #1e293b;
    --text-muted: #475569;
    --accent-1: #3b82f6; /* Blue */
    --accent-2: #ec4899; /* Pink */
    --accent-3: #10b981; /* Green */
    --card-bg: rgba(255, 255, 255, 0.7);
    --card-border: rgba(255, 255, 255, 0.5);
    
    /* Fonts */
    --font-heading: 'Outfit', sans-serif;
    --font-body: 'Inter', sans-serif;
}

/* Dark Theme Overrides - Group 2 */
.dark-theme {
    --bg-primary: #0f172a;
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --accent-1: #38bdf8;
    --accent-2: #818cf8;
    --accent-3: #f472b6;
    --card-bg: rgba(30, 41, 59, 0.7);
    --card-border: rgba(255, 255, 255, 0.1);
}

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

body {
    font-family: var(--font-body);
    background-color: var(--bg-primary);
    color: var(--text-main);
    overflow-x: hidden;
    transition: background-color 0.5s ease, color 0.5s ease;
    min-height: 100vh;
}

/* Background Animated Shapes */
.bg-shape {
    position: fixed;
    border-radius: 50%;
    filter: blur(80px);
    z-index: -1;
    animation: float 10s infinite alternate ease-in-out;
}

.bg-shape-1 {
    width: 400px;
    height: 400px;
    background: var(--accent-1);
    top: -100px;
    left: -100px;
    opacity: 0.3;
}

.bg-shape-2 {
    width: 300px;
    height: 300px;
    background: var(--accent-2);
    bottom: -50px;
    right: -50px;
    opacity: 0.3;
    animation-delay: -5s;
}

@keyframes float {
    0% { transform: translate(0, 0) scale(1); }
    100% { transform: translate(30px, 50px) scale(1.1); }
}

/* Layout */
.app-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-bottom: 2rem;
}

.logo {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 800;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--accent-1);
}

#home-btn {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    color: var(--text-main);
    padding: 0.5rem 1rem;
    border-radius: 20px;
    cursor: pointer;
    font-family: var(--font-heading);
    font-weight: 600;
    backdrop-filter: blur(10px);
    transition: all 0.3s ease;
}

#home-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

/* Views */
.view {
    display: none;
    opacity: 0;
    animation: fadeIn 0.5s forwards;
    flex: 1;
}

.view.active {
    display: block;
}

@keyframes fadeIn {
    to { opacity: 1; }
}

.hidden {
    display: none !important;
}

/* Typography */
h1, h2, h3, h4 {
    font-family: var(--font-heading);
}

p {
    line-height: 1.6;
}

/* Landing Page */
#landing {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
}

.hero-text h1 {
    font-size: 3.5rem;
    background: linear-gradient(135deg, var(--accent-1), var(--accent-2));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 1rem;
}

.hero-text p {
    font-size: 1.2rem;
    color: var(--text-muted);
    margin-bottom: 3rem;
}

.class-selection {
    display: flex;
    gap: 2rem;
    justify-content: center;
    flex-wrap: wrap;
}

.class-card {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 24px;
    padding: 3rem 2rem;
    width: 300px;
    cursor: pointer;
    backdrop-filter: blur(20px);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.05);
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.class-card:hover {
    transform: translateY(-10px) scale(1.02);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.1);
}

.class-card.junior:hover {
    border-color: var(--accent-1);
}

.class-card.senior:hover {
    border-color: var(--accent-2);
}

.card-icon {
    font-size: 3rem;
    margin-bottom: 1.5rem;
    color: var(--accent-1);
}

.class-card.senior .card-icon {
    color: var(--accent-2);
}

.class-card h2 {
    font-size: 1.8rem;
    margin-bottom: 0.5rem;
}

.class-card p {
    color: var(--text-muted);
    margin-bottom: 2rem;
}

.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: 30px;
    background: linear-gradient(135deg, var(--accent-1), var(--accent-2));
    color: white;
    font-weight: 600;
    transition: transform 0.3s ease;
}

.class-card:hover .btn {
    transform: translateX(5px);
}

/* Glass Panels */
.page-title {
    font-size: 2.5rem;
    margin-bottom: 2rem;
    display: flex;
    align-items: center;
    gap: 1rem;
}

.badge {
    font-size: 1rem;
    background: var(--accent-2);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 12px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.content-grid {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 2rem;
}

.glass-panel {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 20px;
    padding: 2rem;
    backdrop-filter: blur(20px);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.05);
}

.glass-panel h3 {
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
    color: var(--accent-1);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.full-width {
    grid-column: 1 / -1;
}

/* Group 1 Cards */
.idea-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
}

.idea-card {
    background: rgba(255,255,255,0.5);
    padding: 1.5rem;
    border-radius: 16px;
    text-align: center;
    transition: transform 0.3s ease;
}

.idea-card:hover {
    transform: translateY(-5px);
}

.idea-card .icon {
    font-size: 2rem;
    color: var(--accent-1);
    margin-bottom: 1rem;
}

.idea-card h4 {
    margin-bottom: 0.5rem;
}

.idea-card p {
    font-size: 0.9rem;
    color: var(--text-muted);
}

/* Group 2 Tech Cards */
.tech-cards {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.tech-card {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    background: rgba(0,0,0,0.2);
    padding: 1.5rem;
    border-radius: 12px;
    border-left: 4px solid var(--accent-1);
    transition: all 0.3s ease;
}

.tech-card:hover {
    transform: translateX(5px);
    background: rgba(0,0,0,0.3);
}

.tech-card .icon {
    font-size: 2rem;
    color: var(--accent-2);
}

.tech-card h4 {
    margin-bottom: 0.25rem;
}

.tech-card p {
    font-size: 0.9rem;
    color: var(--text-muted);
}

/* Activities */
.activity-box {
    background: rgba(0,0,0,0.05);
    padding: 1.5rem;
    border-radius: 12px;
}

.dark-theme .activity-box {
    background: rgba(255,255,255,0.05);
}

.steps {
    list-style: none;
    margin-top: 1rem;
}

.steps li {
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 1rem;
    font-weight: 500;
}

.steps span {
    background: var(--accent-1);
    color: white;
    width: 28px;
    height: 28px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    font-size: 0.9rem;
}

.comparison-grid {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    margin: 1rem 0;
}

.comp-item {
    background: var(--accent-1);
    color: white;
    padding: 0.75rem;
    border-radius: 8px;
    text-align: center;
    font-weight: 600;
    font-size: 0.9rem;
    cursor: pointer;
    transition: transform 0.2s ease, opacity 0.2s ease;
}

.comp-item:hover {
    transform: translateY(-2px);
    opacity: 0.92;
}

.reflection-prompt {
    font-size: 0.95rem;
    font-style: italic;
    color: var(--text-muted);
}

.comparison-panel {
    margin-top: -0.5rem;
}

.comparison-intro {
    color: var(--text-muted);
    margin-bottom: 1.5rem;
}

.compare-accordion {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.compare-item,
.reflection-box,
.summary-box {
    background: rgba(255,255,255,0.05);
    border: 1px solid var(--card-border);
    border-radius: 14px;
}

.compare-item {
    overflow: hidden;
}

.compare-header {
    padding: 1.1rem 1.25rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    font-weight: 700;
}

.compare-header:hover {
    background: rgba(255,255,255,0.04);
}

.compare-content {
    padding: 0 1.25rem;
    max-height: 0;
    overflow: hidden;
    transition: all 0.3s ease;
}

.compare-item.active .compare-content {
    padding: 0 1.25rem 1.25rem;
    max-height: 420px;
}

.compare-item.active .compare-header i {
    transform: rotate(45deg);
    color: var(--accent-2);
}

.reflection-box,
.summary-box {
    padding: 1.25rem;
}

.reflection-box h4,
.summary-box h4 {
    margin-bottom: 1rem;
}

.compare-header {
    margin-bottom: 0;
}

.compare-header span {
    flex: 1;
}

.compare-header i {
    transition: transform 0.3s ease, color 0.3s ease;
}

.compare-columns {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.compare-content h5 {
    font-size: 0.95rem;
    margin-bottom: 0.5rem;
    color: var(--accent-1);
}

.compare-content ul,
.reflection-box ul {
    padding-left: 1.2rem;
}

.compare-content li,
.reflection-box li {
    margin-bottom: 0.5rem;
    color: var(--text-muted);
}

.takeaway {
    margin-top: 1rem;
    padding-top: 1rem;
    border-top: 1px solid var(--card-border);
}

.reflection-summary {
    display: grid;
    grid-template-columns: 1fr 1.2fr;
    gap: 1rem;
    margin-top: 1rem;
}

.summary-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0.75rem;
}

.summary-item {
    background: rgba(0,0,0,0.2);
    border-radius: 10px;
    padding: 0.85rem;
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.summary-item span {
    color: var(--text-muted);
    font-size: 0.9rem;
}

.rule-note {
    margin-top: 1rem;
    color: var(--text-muted);
}

/* Questions Group 1 */
.question-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.q-card {
    background: rgba(255,255,255,0.6);
    border-radius: 12px;
    overflow: hidden;
    cursor: pointer;
    border: 1px solid transparent;
    transition: all 0.3s;
}

.q-card:hover {
    border-color: var(--accent-1);
}

.q-header {
    padding: 1rem 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-weight: 600;
}

.q-answer {
    padding: 0 1.5rem;
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    transition: all 0.3s ease;
    color: var(--accent-1);
}

.q-card.open .q-answer {
    padding: 0 1.5rem 1.5rem;
    max-height: 100px;
    opacity: 1;
}

.q-card.open .q-header i {
    transform: rotate(180deg);
}

/* Accordion Group 2 */
.accordion {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.acc-item {
    background: rgba(0,0,0,0.2);
    border-radius: 8px;
    border: 1px solid var(--card-border);
}

.acc-header {
    padding: 1rem 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    font-weight: 600;
    transition: background 0.3s;
}

.acc-header:hover {
    background: rgba(255,255,255,0.05);
}

.acc-content {
    padding: 0 1.5rem;
    max-height: 0;
    overflow: hidden;
    transition: all 0.3s ease;
    color: var(--text-muted);
}

.acc-item.active .acc-content {
    padding: 0 1.5rem 1.5rem;
    max-height: 200px;
}

.acc-item.active .acc-header i {
    transform: rotate(45deg);
    color: var(--accent-2);
}

/* Stability Panel */
.stability-panel {
    margin-bottom: 2rem;
}

.stability-layout {
    display: flex;
    gap: 2rem;
    margin-top: 1.5rem;
}

.stability-text {
    flex: 2;
}

.stability-visuals {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.stability-img {
    width: 100%;
    border-radius: 12px;
    border: 1px solid var(--card-border);
}

.rule-box {
    padding: 1rem;
    border-radius: 8px;
    margin: 0.5rem 0 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.rule-box.success {
    background: rgba(16, 185, 129, 0.2);
    border-left: 4px solid var(--accent-3);
}

.rule-box.danger {
    background: rgba(239, 68, 68, 0.2);
    border-left: 4px solid #ef4444;
}

.dart-analogy {
    background: rgba(255,255,255,0.05);
    padding: 1rem;
    border-radius: 8px;
    margin-bottom: 1.5rem;
    border-left: 4px solid var(--accent-1);
}

.stability-text ul {
    padding-left: 1.5rem;
    margin-bottom: 1.5rem;
}

.stability-text li {
    margin-bottom: 0.5rem;
}

.test-box {
    background: rgba(255,255,255,0.05);
    padding: 1rem;
    border-radius: 8px;
}

/* Facts & Dynamics Panels */
.facts-grid, .dynamics-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
}

.fact-card, .dyn-item {
    background: rgba(255,255,255,0.05);
    padding: 1.5rem;
    border-radius: 12px;
    border: 1px solid var(--card-border);
    transition: transform 0.3s ease;
}

.dark-theme .fact-card, .dark-theme .dyn-item {
    background: rgba(0,0,0,0.2);
}

.fact-card:hover, .dyn-item:hover {
    transform: translateY(-5px);
}

.fact-card .icon, .dyn-item h4 i {
    font-size: 1.5rem;
    color: var(--accent-1);
    margin-bottom: 0.5rem;
}

.dyn-item h4 i {
    margin-right: 0.5rem;
}

.fact-card h4, .dyn-item h4 {
    margin-bottom: 0.5rem;
    color: var(--text-main);
}

.fact-card p, .dyn-item p {
    font-size: 0.95rem;
    color: var(--text-muted);
}

/* Real World & Industry Panels */
.real-world-panel {
    margin-bottom: 2rem;
}

.rw-layout {
    display: flex;
    gap: 2rem;
    margin-top: 1.5rem;
    align-items: center;
}

.rw-text {
    flex: 1;
}

.rw-text h4 {
    margin-bottom: 0.5rem;
    color: var(--accent-1);
}

.rw-text p {
    margin-bottom: 1.5rem;
}

.rw-text ul {
    padding-left: 1.5rem;
    margin-bottom: 1.5rem;
}

.rw-text li {
    margin-bottom: 0.75rem;
    color: var(--text-muted);
}

.rw-text strong {
    color: var(--text-main);
}

.rw-visual {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.rw-img {
    width: 100%;
    max-width: 500px;
    border-radius: 12px;
    border: 1px solid var(--card-border);
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
}

.img-caption {
    margin-top: 0.75rem;
    font-size: 0.9rem;
    color: var(--text-muted);
    font-style: italic;
}

.industry-intro {
    margin-bottom: 1.5rem;
    color: var(--text-muted);
}

.industry-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
}

.industry-card {
    background: rgba(0,0,0,0.2);
    padding: 1.5rem;
    border-radius: 12px;
    border: 1px solid var(--card-border);
    transition: transform 0.3s ease;
}

.industry-card:hover {
    transform: translateY(-5px);
}

.industry-card .icon {
    font-size: 2rem;
    margin-bottom: 1rem;
    color: var(--accent-1);
}

.industry-card h4 {
    margin-bottom: 0.5rem;
    color: var(--text-main);
}

.industry-card p {
    font-size: 0.95rem;
    color: var(--text-muted);
    margin-bottom: 0.5rem;
}

.industry-card p strong {
    color: var(--accent-2);
}

/* Responsive */
.rw-divider {
    border: none;
    border-top: 1px dashed var(--card-border);
    margin: 3rem 0;
}

.industry-img {
    width: 100%;
    border-radius: 8px;
    margin-bottom: 1rem;
    object-fit: cover;
    max-height: 150px;
}

/* Landing Gallery */
.landing-gallery {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    margin: 2.5rem 0;
    flex-wrap: wrap;
}

.landing-img {
    height: 220px;
    width: auto;
    max-width: 100%;
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.4);
    border: 2px solid var(--card-border);
    object-fit: cover;
    transition: transform 0.3s ease;
}

.landing-img:hover {
    transform: scale(1.05);
}

/* Quiz Styles */
.options-grid {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.option-btn {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    color: var(--text-main);
    padding: 1.2rem;
    border-radius: 8px;
    font-size: 1.1rem;
    cursor: pointer;
    text-align: left;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.option-btn:hover:not(:disabled) {
    background: rgba(255, 255, 255, 0.05);
    border-color: var(--accent-1);
    transform: translateX(5px);
}

.option-btn.correct {
    background: rgba(46, 213, 115, 0.2);
    border-color: #2ed573;
}

.option-btn.incorrect {
    background: rgba(255, 71, 87, 0.2);
    border-color: #ff4757;
}

.option-btn:disabled {
    cursor: default;
}

/* Presentation Form Styles */
.form-group {
    margin-bottom: 1.5rem;
    text-align: left;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: bold;
    color: var(--accent-1);
}

.form-input {
    width: 100%;
    padding: 0.8rem;
    background: rgba(0, 0, 0, 0.2);
    border: 1px solid var(--card-border);
    border-radius: 8px;
    color: var(--text-main);
    font-family: inherit;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

.form-input:focus {
    outline: none;
    border-color: var(--accent-1);
}

.report-card {
    box-shadow: 0 10px 30px rgba(0,0,0,0.5);
}

/* Demo Table Hover */
.demo-table tbody tr {
    transition: background-color 0.2s ease;
}

.demo-table tbody tr:hover {
    background: rgba(255, 255, 255, 0.05) !important;
}

@media (max-width: 900px) {
    .rw-layout {
        flex-direction: column;
    }
    .content-grid {
        grid-template-columns: 1fr;
    }
    .stability-layout {
        flex-direction: column-reverse;
    }
    .compare-columns,
    .reflection-summary,
    .summary-grid {
        grid-template-columns: 1fr;
    }
}