/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #3b82f6;
    --secondary: #10b981;
    --dark: #0f172a;
    --dark-lighter: #1e293b;
    --gray: #64748b;
    --light-gray: #e2e8f0;
    --white: #ffffff;
    --background: #f8fafc;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    line-height: 1.6;
    color: var(--dark);
    background: var(--white);
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 24px;
}

h1, h2, h3, h4 {
    line-height: 1.2;
    font-weight: 700;
}

h1 { font-size: 3rem; }
h2 { font-size: 2.25rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.125rem; }

@media (max-width: 768px) {
    h1 { font-size: 2.25rem; }
    h2 { font-size: 1.75rem; }
    h3 { font-size: 1.25rem; }
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    padding: 16px 0;
    border-bottom: 1px solid var(--light-gray);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    flex-direction: column;
    line-height: 1.2;
}

.logo-product {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary);
}

.logo-company {
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--gray);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 24px;
}

@media (max-width: 1024px) {
    .nav-links {
        gap: 16px;
    }
}

@media (max-width: 900px) {
    .nav-links {
        display: none;
    }
}

.nav-link {
    color: var(--dark);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.875rem;
    transition: color 0.2s;
    white-space: nowrap;
}

.nav-link:hover {
    color: var(--primary);
}

.nav-cta {
    background: var(--primary);
    color: var(--white);
    padding: 10px 20px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    font-size: 0.875rem;
    transition: background 0.2s;
}

.nav-cta:hover {
    background: var(--primary-dark);
}

/* Hero Section */
.hero {
    padding: 160px 0 100px;
    background: linear-gradient(180deg, var(--background) 0%, var(--white) 100%);
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

@media (max-width: 900px) {
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .hero-image {
        order: -1;
    }
}

.hero-text {
    text-align: left;
}

@media (max-width: 900px) {
    .hero-text {
        text-align: center;
    }
}

.hero h1 {
    margin-bottom: 24px;
}

.hero .highlight {
    color: var(--primary);
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--gray);
    max-width: 600px;
    margin-bottom: 40px;
}

@media (max-width: 900px) {
    .hero-subtitle {
        margin: 0 auto 40px;
    }
}

.hero-image {
    display: flex;
    justify-content: center;
    align-items: center;
}

.hero-image img {
    max-width: 100%;
    height: auto;
    border-radius: 16px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.15);
}

.hero-video {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.hero-video .video-container {
    max-width: 100%;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.15);
    background: var(--dark);
}

.hero-video .demo-video {
    width: 100%;
    height: auto;
    display: block;
}

.video-clarification {
    font-size: 0.95rem;
    color: var(--gray);
    font-style: italic;
    text-align: center;
    line-height: 1.5;
}

@media (max-width: 900px) {
    .hero-video {
        order: -1;
    }
}

.cta-button {
    display: inline-block;
    background: var(--primary);
    color: var(--white);
    padding: 16px 32px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    font-size: 1.125rem;
    border: none;
    cursor: pointer;
    transition: all 0.2s;
}

.cta-button:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
}

.hero-note {
    margin-top: 16px;
    color: var(--gray);
    font-size: 0.875rem;
}

/* Learning Comparison Section */
.learning-comparison {
    padding: 100px 0;
    background: var(--background);
}

.learning-comparison h2 {
    text-align: center;
    margin-bottom: 50px;
}

.comparison-visual {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    gap: 30px;
    max-width: 900px;
    margin: 0 auto;
    align-items: center;
}

@media (max-width: 768px) {
    .comparison-visual {
        grid-template-columns: 1fr;
        gap: 20px;
    }
}

.learning-method {
    padding: 40px;
    border-radius: 16px;
    text-align: center;
}

.learning-method.passive {
    background: var(--white);
    border: 2px solid var(--light-gray);
}

.learning-method.active {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: var(--white);
}

.learning-method h3 {
    margin-bottom: 24px;
    font-size: 1.5rem;
}

.learning-method ul {
    list-style: none;
    text-align: left;
}

.learning-method li {
    padding: 10px 0;
    padding-left: 28px;
    position: relative;
    font-size: 1rem;
}

.learning-method.passive li {
    color: var(--gray);
}

.learning-method.passive li::before {
    content: "✗";
    position: absolute;
    left: 0;
    color: var(--gray);
    font-weight: bold;
}

.learning-method.active li::before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--secondary);
    font-weight: bold;
}

.vs-divider {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--gray);
    text-transform: uppercase;
}

@media (max-width: 768px) {
    .vs-divider {
        transform: rotate(90deg);
    }
}

/* Problem Section */
.problem {
    padding: 100px 0;
    background: var(--white);
}

.problem h2 {
    text-align: center;
    margin-bottom: 50px;
}

.problem-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
    margin-bottom: 50px;
}

@media (max-width: 768px) {
    .problem-grid {
        grid-template-columns: 1fr;
    }
}

.problem-card {
    text-align: center;
    padding: 30px;
    background: var(--background);
    border-radius: 12px;
}

.problem-icon {
    font-size: 2.5rem;
    margin-bottom: 16px;
}

.problem-card h3 {
    margin-bottom: 8px;
    color: var(--dark);
}

.problem-card p {
    color: var(--gray);
}

.problem-statement {
    text-align: center;
    font-size: 1.25rem;
    color: var(--dark);
    max-width: 600px;
    margin: 0 auto;
}

/* Problem Visual */
.problem-visual {
    text-align: center;
    margin-bottom: 40px;
}

.problem-main-image {
    max-width: 500px;
    width: 100%;
    height: auto;
    border-radius: 16px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
}

.problem-card-image {
    width: 80px;
    height: 80px;
    object-fit: contain;
    margin-bottom: 16px;
}

/* Solution Section */
.solution {
    padding: 100px 0;
    background: var(--dark);
    color: var(--white);
}

.solution h2 {
    text-align: center;
    margin-bottom: 40px;
}

.solution-visual {
    text-align: center;
    margin-bottom: 40px;
}

.solution-main-image {
    max-width: 600px;
    width: 100%;
    height: auto;
    border-radius: 16px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
}

.solution-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

@media (max-width: 768px) {
    .solution-content {
        grid-template-columns: 1fr;
    }
}

.conversation-demo {
    background: var(--dark-lighter);
    border-radius: 16px;
    padding: 30px;
}

.message {
    margin-bottom: 20px;
    padding: 16px 20px;
    border-radius: 12px;
}

.message:last-child {
    margin-bottom: 0;
}

.message.ai {
    background: var(--primary);
    margin-right: 30px;
}

.message.student {
    background: rgba(255, 255, 255, 0.1);
    margin-left: 30px;
}

.message .speaker {
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    opacity: 0.8;
    display: block;
    margin-bottom: 8px;
}

.message p {
    font-size: 0.95rem;
    line-height: 1.5;
}

.solution-features {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.feature {
    display: flex;
    gap: 16px;
    align-items: flex-start;
}

.feature-icon {
    font-size: 1.5rem;
    flex-shrink: 0;
}

.feature h4 {
    margin-bottom: 4px;
}

.feature p {
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.95rem;
}

.feature-image {
    width: 60px;
    height: 60px;
    object-fit: contain;
    flex-shrink: 0;
}

/* Differentiator Section */
.differentiator {
    padding: 100px 0;
    background: var(--white);
    text-align: center;
}

.differentiator h2 {
    margin-bottom: 12px;
}

.diff-subtitle {
    color: var(--gray);
    margin-bottom: 30px;
    font-size: 1.125rem;
}

.differentiator-visuals {
    display: flex;
    justify-content: center;
    gap: 30px;
    margin-bottom: 50px;
    flex-wrap: wrap;
}

.diff-image {
    max-width: 350px;
    width: 100%;
    height: auto;
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

.comparison-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
    max-width: 800px;
    margin: 0 auto;
}

@media (max-width: 768px) {
    .comparison-grid {
        grid-template-columns: 1fr;
    }
}

.comparison-card {
    padding: 40px;
    border-radius: 16px;
    text-align: left;
}

.comparison-card.traditional {
    background: var(--background);
    border: 2px solid var(--light-gray);
}

.comparison-card.modern {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: var(--white);
}

.comparison-card h3 {
    margin-bottom: 20px;
}

.comparison-card ul {
    list-style: none;
}

.comparison-card li {
    padding: 8px 0;
    padding-left: 24px;
    position: relative;
}

.comparison-card.traditional li::before {
    content: "✗";
    position: absolute;
    left: 0;
    color: var(--gray);
}

.comparison-card.modern li::before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--secondary);
}

/* Why It Works Section */
.why-it-works {
    padding: 100px 0;
    background: var(--background);
}

.why-it-works h2 {
    text-align: center;
    margin-bottom: 50px;
}

.science-content {
    max-width: 900px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
    align-items: center;
}

@media (max-width: 768px) {
    .science-content {
        grid-template-columns: 1fr;
    }
}

.science-image {
    text-align: center;
}

.why-image {
    max-width: 100%;
    height: auto;
    border-radius: 16px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
}

.big-quote {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--primary);
    margin-bottom: 30px;
    line-height: 1.4;
}

.science-text p {
    margin-bottom: 20px;
    color: var(--dark);
}

.science-text ul {
    list-style: none;
    margin-bottom: 20px;
}

.science-text li {
    padding: 12px 0;
    padding-left: 32px;
    position: relative;
}

.science-text li::before {
    content: "→";
    position: absolute;
    left: 0;
    color: var(--primary);
    font-weight: bold;
}

/* Research Validation Section */
.research-validation {
    padding: 100px 0;
    background: var(--white);
}

.research-validation h2 {
    text-align: center;
    margin-bottom: 60px;
}

.research-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
    margin-bottom: 50px;
}

@media (max-width: 900px) {
    .research-grid {
        grid-template-columns: 1fr;
        gap: 30px;
    }
}

.research-card {
    background: var(--background);
    padding: 40px 30px;
    border-radius: 16px;
    text-align: center;
    border: 2px solid var(--light-gray);
    transition: all 0.3s;
}

.research-card:hover {
    border-color: var(--primary);
    box-shadow: 0 10px 30px rgba(37, 99, 235, 0.1);
    transform: translateY(-4px);
}

.research-stat {
    font-size: 3.5rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 16px;
    line-height: 1;
}

.research-card h4 {
    margin-bottom: 12px;
    color: var(--dark);
}

.research-card p {
    color: var(--gray);
    margin-bottom: 20px;
    line-height: 1.6;
}

.research-source {
    display: block;
    font-size: 0.75rem;
    color: var(--gray);
    font-style: italic;
    border-top: 1px solid var(--light-gray);
    padding-top: 16px;
}

.research-source a {
    color: var(--primary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
}

.research-source a:hover {
    color: var(--primary-dark);
    text-decoration: underline;
}

.research-conclusion {
    text-align: center;
    font-size: 1.25rem;
    color: var(--dark);
    max-width: 800px;
    margin: 0 auto;
    line-height: 1.6;
}

/* Who It's For Section */
.who-its-for {
    padding: 100px 0;
    background: var(--white);
}

.who-its-for h2 {
    text-align: center;
    margin-bottom: 50px;
}

.audience-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
    max-width: 900px;
    margin: 0 auto;
}

@media (max-width: 900px) {
    .audience-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 600px) {
    .audience-grid {
        grid-template-columns: 1fr;
    }
}

.audience-card {
    text-align: center;
    padding: 30px 20px;
    background: var(--background);
    border-radius: 12px;
    transition: transform 0.2s;
}

.audience-card:hover {
    transform: translateY(-4px);
}

.audience-icon {
    font-size: 2.5rem;
    margin-bottom: 16px;
}

.audience-image {
    width: 100px;
    height: 100px;
    object-fit: cover;
    border-radius: 50%;
    margin-bottom: 16px;
}

.audience-card h3 {
    margin-bottom: 8px;
    font-size: 1.125rem;
}

.audience-card p {
    color: var(--gray);
    font-size: 0.95rem;
}

/* CTA Section */
.cta-section {
    padding: 100px 0;
    background: linear-gradient(135deg, var(--dark) 0%, var(--dark-lighter) 100%);
    color: var(--white);
    text-align: center;
}

.cta-section h2 {
    margin-bottom: 16px;
}

.cta-section > .container > p {
    color: rgba(255, 255, 255, 0.8);
    margin-bottom: 12px;
}

.cta-benefits {
    list-style: none;
    margin-bottom: 40px;
}

.cta-benefits li {
    padding: 8px 0;
    color: rgba(255, 255, 255, 0.9);
}

.signup-form {
    display: flex;
    gap: 12px;
    max-width: 500px;
    margin: 0 auto 16px;
}

@media (max-width: 600px) {
    .signup-form {
        flex-direction: column;
    }
}

.signup-form input {
    flex: 1;
    padding: 16px 20px;
    border: 2px solid rgba(255, 255, 255, 0.2);
    border-radius: 8px;
    background: rgba(255, 255, 255, 0.1);
    color: var(--white);
    font-size: 1rem;
    font-family: inherit;
}

.signup-form input::placeholder {
    color: rgba(255, 255, 255, 0.5);
}

.signup-form input:focus {
    outline: none;
    border-color: var(--primary);
    background: rgba(255, 255, 255, 0.15);
}

.signup-form .cta-button {
    flex-shrink: 0;
}

.form-note {
    color: rgba(255, 255, 255, 0.5);
    font-size: 0.875rem;
}

.success-message {
    display: none;
    background: var(--secondary);
    padding: 30px;
    border-radius: 12px;
    max-width: 400px;
    margin: 0 auto;
}

.success-message.show {
    display: block;
}

.success-message h3 {
    margin-bottom: 8px;
}

/* Footer */
.footer {
    padding: 60px 0 30px;
    background: var(--dark);
    background-size: cover;
    background-position: center;
    background-blend-mode: overlay;
    color: rgba(255, 255, 255, 0.7);
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 40px;
}

@media (max-width: 600px) {
    .footer-content {
        flex-direction: column;
        gap: 20px;
        text-align: center;
    }
}

.footer-brand .logo {
    color: var(--white);
    margin-bottom: 8px;
}

.footer-links a {
    color: var(--primary-light);
    text-decoration: none;
}

.footer-links a:hover {
    text-decoration: underline;
}

.copyright {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    font-size: 0.875rem;
}

/* Product Badge */
.product-badge {
    display: inline-block;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: var(--white);
    padding: 8px 16px;
    border-radius: 50px;
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 16px;
    letter-spacing: 0.5px;
}

/* FAQ Page Styles */
.faq-hero {
    padding: 140px 0 60px;
    background: linear-gradient(180deg, var(--background) 0%, var(--white) 100%);
    text-align: center;
}

.faq-hero h1 {
    margin-bottom: 16px;
}

.faq-hero p {
    color: var(--gray);
    font-size: 1.125rem;
    max-width: 600px;
    margin: 0 auto;
}

.faq-section {
    padding: 60px 0 100px;
}

.faq-container {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    background: var(--white);
    border: 1px solid var(--light-gray);
    border-radius: 12px;
    margin-bottom: 16px;
    overflow: hidden;
    transition: box-shadow 0.2s;
}

.faq-item:hover {
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

.faq-question {
    width: 100%;
    padding: 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: none;
    border: none;
    cursor: pointer;
    text-align: left;
    font-family: inherit;
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--dark);
    transition: color 0.2s;
}

.faq-question:hover {
    color: var(--primary);
}

.faq-icon {
    font-size: 1.5rem;
    color: var(--primary);
    transition: transform 0.3s;
    flex-shrink: 0;
    margin-left: 16px;
}

.faq-item.active .faq-icon {
    transform: rotate(45deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out;
}

.faq-answer-content {
    padding: 0 24px 24px;
    color: var(--gray);
    line-height: 1.7;
}

.faq-answer-content strong {
    color: var(--dark);
}

.faq-item.active .faq-answer {
    max-height: 500px;
}

.faq-cta {
    text-align: center;
    padding: 60px 0;
    background: var(--background);
    border-radius: 16px;
    margin-top: 60px;
}

.faq-cta h3 {
    margin-bottom: 16px;
}

.faq-cta p {
    color: var(--gray);
    margin-bottom: 24px;
}

.footer-links {
    display: flex;
    flex-direction: column;
    gap: 8px;
    align-items: flex-end;
}

@media (max-width: 600px) {
    .footer-links {
        align-items: center;
    }
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.hero h1,
.hero-subtitle,
.hero .cta-button {
    animation: fadeIn 0.6s ease-out forwards;
}

.hero-subtitle {
    animation-delay: 0.1s;
}

.hero .cta-button {
    animation-delay: 0.2s;
}