/* ====================
   Gemini Storybook - Main Styles
   ==================== */

/* CSS Variables - Google Material Design Colors */
:root {
    /* Google Official Colors */
    --color-primary: #1a73e8;
    --color-primary-dark: #1557b0;
    --color-primary-light: #4285f4;
    --color-secondary: #34a853;
    --color-accent: #fbbc04;
    --color-danger: #ea4335;
    
    /* Background Colors */
    --color-bg: #ffffff;
    --color-bg-alt: #f8f9fa;
    --color-bg-hover: #f1f3f4;
    
    /* Text Colors */
    --color-text: #202124;
    --color-text-secondary: #5f6368;
    --color-text-tertiary: #80868b;
    
    /* Border & Divider */
    --color-border: #e8eaed;
    --color-divider: #dadce0;
    
    /* Spacing - Google uses generous spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 3rem;
    --spacing-xl: 5rem;
    --spacing-xxl: 7rem;
    
    /* Border Radius - More subtle */
    --border-radius: 4px;
    --border-radius-md: 8px;
    --border-radius-lg: 12px;
    
    /* Transitions - Google's smooth transitions */
    --transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    
    /* Shadows - Material Design elevation */
    --shadow-1: 0 1px 2px 0 rgba(60, 64, 67, 0.3), 0 1px 3px 1px rgba(60, 64, 67, 0.15);
    --shadow-2: 0 1px 2px 0 rgba(60, 64, 67, 0.3), 0 2px 6px 2px rgba(60, 64, 67, 0.15);
    --shadow-3: 0 1px 3px 0 rgba(60, 64, 67, 0.3), 0 4px 8px 3px rgba(60, 64, 67, 0.15);
    
    /* Layout */
    --max-width: 1200px;
    --content-width: 800px;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Google Sans', 'Roboto', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
    font-size: 16px;
    line-height: 1.5;
    color: var(--color-text);
    background-color: var(--color-bg);
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

a {
    color: var(--color-primary);
    text-decoration: none;
    transition: var(--transition);
}

a:hover {
    color: var(--color-primary-dark);
}

/* Typography - Google Sans style */
h1, h2, h3, h4, h5, h6 {
    font-family: 'Google Sans', 'Roboto', sans-serif;
    font-weight: 400;
    line-height: 1.2;
    margin-bottom: var(--spacing-md);
    color: var(--color-text);
    letter-spacing: -0.02em;
}

h1 {
    font-size: clamp(2.5rem, 5vw, 4.5rem);
    font-weight: 400;
    line-height: 1.1;
}

h2 {
    font-size: clamp(2rem, 4vw, 3.5rem);
    font-weight: 400;
    line-height: 1.2;
}

h3 {
    font-size: clamp(1.5rem, 3vw, 2rem);
    font-weight: 500;
    line-height: 1.3;
}

p {
    margin-bottom: var(--spacing-sm);
}

strong {
    font-weight: 500;
    color: var(--color-text);
}

/* Container */
.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* Section */
.section {
    padding: var(--spacing-xxl) 0;
}

.section-header {
    text-align: center;
    max-width: 800px;
    margin: 0 auto var(--spacing-lg);
}

.section-header h2 {
    margin-bottom: var(--spacing-md);
}

.section-header p {
    font-size: 1.125rem;
    color: var(--color-text-secondary);
    line-height: 1.6;
    font-weight: 400;
}

/* Header & Navigation - Google style */
.header {
    position: sticky;
    top: 0;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--color-border);
    z-index: 1000;
    box-shadow: none;
}

.nav {
    padding: var(--spacing-sm) 0;
}

.nav-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.375rem;
    font-weight: 400;
    color: var(--color-text);
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-family: 'Google Sans', 'Roboto', sans-serif;
}

.google-logo {
    height: 24px;
    width: auto;
    display: block;
}

.logo:hover {
    color: var(--color-text);
    opacity: 0.8;
}

.logo-text {
    color: var(--color-text);
    font-weight: 500;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-xs);
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background: var(--color-text);
    border-radius: 2px;
    transition: var(--transition);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--spacing-md);
    align-items: center;
}

.nav-menu a {
    color: var(--color-text-secondary);
    font-weight: 400;
    font-size: 0.9375rem;
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--border-radius);
    transition: var(--transition);
}

.nav-menu a:hover {
    background: var(--color-bg-hover);
    color: var(--color-text);
}

/* Buttons - Material Design style */
.btn-primary,
.btn-large {
    display: inline-block;
    background: var(--color-primary);
    color: white !important;
    padding: 0.75rem 1.5rem;
    border-radius: 24px;
    font-weight: 500;
    font-size: 0.875rem;
    text-align: center;
    transition: var(--transition);
    border: none;
    cursor: pointer;
    box-shadow: none;
    font-family: 'Google Sans', 'Roboto', sans-serif;
    letter-spacing: 0.01em;
    text-transform: none;
}

.btn-primary:hover,
.btn-large:hover {
    background: var(--color-primary-dark);
    box-shadow: 0 1px 3px 0 rgba(60, 64, 67, 0.3), 0 4px 8px 3px rgba(60, 64, 67, 0.15);
}

.btn-large {
    padding: 0.875rem 2rem;
    font-size: 0.9375rem;
}

/* Hero Section - Google clean style */
.hero {
    background: white;
    color: var(--color-text);
    padding: var(--spacing-xxl) 0 var(--spacing-xl);
    position: relative;
    overflow: hidden;
    border-bottom: 1px solid var(--color-border);
}

.hero .container {
    position: relative;
    z-index: 1;
}

.hero-content {
    max-width: 700px;
    margin-bottom: var(--spacing-lg);
}

.hero-title {
    margin-bottom: var(--spacing-md);
}

.gradient-text {
    display: block;
    font-size: clamp(3rem, 6vw, 5.5rem);
    font-weight: 400;
    color: var(--color-text);
    margin-bottom: var(--spacing-sm);
    letter-spacing: -0.04em;
}

.subtitle {
    display: block;
    font-size: clamp(1.25rem, 2.5vw, 1.5rem);
    font-weight: 400;
    color: var(--color-text-secondary);
    margin-top: var(--spacing-sm);
}

.hero-description {
    font-size: 1.125rem;
    line-height: 1.6;
    margin-bottom: var(--spacing-lg);
    color: var(--color-text-secondary);
    max-width: 600px;
}

.hero-cta {
    margin-top: var(--spacing-md);
}

.hero-cta .btn-large {
    background: var(--color-primary);
    color: white !important;
}

.hero-cta .btn-large:hover {
    background: var(--color-primary-dark);
    box-shadow: 0 1px 3px 0 rgba(60, 64, 67, 0.3), 0 4px 8px 3px rgba(60, 64, 67, 0.15);
}

.hero-video {
    margin-top: var(--spacing-lg);
}

.video-container {
    position: relative;
    width: 100%;
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    background: var(--color-bg-alt);
    border: 1px solid var(--color-border);
}

.hero-video-player {
    width: 100%;
    height: auto;
    display: block;
    max-height: 600px;
    object-fit: cover;
}

/* Features Section */
.features {
    background: var(--color-bg-alt);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-md);
    margin-top: var(--spacing-lg);
}

.feature-card {
    background: white;
    padding: var(--spacing-lg);
    border-radius: var(--border-radius-md);
    border: 1px solid var(--color-border);
    transition: var(--transition);
}

.feature-card:hover {
    border-color: var(--color-primary-light);
    box-shadow: var(--shadow-2);
}

.feature-icon {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-md);
    color: var(--color-primary);
}

.feature-card h3 {
    color: var(--color-text);
    margin-bottom: var(--spacing-sm);
}

.feature-card p {
    color: var(--color-text-secondary);
    margin-bottom: 0;
}

/* Story Gallery */
.story-gallery {
    background: white;
}

.gallery-carousel {
    margin-top: var(--spacing-lg);
}

.carousel-container {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 400px;
}

.carousel-item {
    display: none;
}

.carousel-item.active {
    display: block;
}

.story-preview {
    text-align: center;
    padding: var(--spacing-lg);
}

.story-image-placeholder {
    font-size: 8rem;
    margin-bottom: var(--spacing-md);
    color: var(--color-text-secondary);
    opacity: 0.6;
}

.story-caption {
    font-size: 1.125rem;
    color: var(--color-text-secondary);
}

.carousel-dots {
    display: flex;
    justify-content: center;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-md);
}

.dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--color-border);
    cursor: pointer;
    transition: var(--transition);
}

.dot.active {
    background: var(--color-primary);
    width: 24px;
    border-radius: 4px;
}

/* How It Works Section */
.how-it-works {
    background: var(--color-bg-alt);
}

.steps-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-md);
    margin-top: var(--spacing-lg);
}

.step-card {
    background: white;
    padding: var(--spacing-lg);
    border-radius: var(--border-radius-md);
    text-align: center;
    border: 1px solid var(--color-border);
    transition: var(--transition);
}

.step-card:hover {
    border-color: var(--color-primary-light);
    box-shadow: var(--shadow-2);
}

.step-number {
    width: 48px;
    height: 48px;
    background: var(--color-primary);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    font-weight: 500;
    margin: 0 auto var(--spacing-md);
}

.step-card h3 {
    margin-bottom: var(--spacing-sm);
}

.step-card p {
    color: var(--color-text-secondary);
    margin-bottom: 0;
}

/* Files to Fables Section */
.files-to-fables {
    background: white;
}

.files-demo {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: var(--spacing-lg);
    margin-top: var(--spacing-lg);
    flex-wrap: wrap;
}

.upload-example,
.story-result {
    background: var(--color-bg-alt);
    padding: var(--spacing-lg);
    border-radius: var(--border-radius-md);
    text-align: center;
    min-width: 250px;
    border: 1px solid var(--color-border);
}

.upload-icon,
.result-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-md);
    color: var(--color-text-secondary);
}

.arrow {
    font-size: 1.5rem;
    color: var(--color-text-secondary);
    font-weight: 400;
}

/* Use Cases Section */
.use-cases {
    background: var(--color-bg-alt);
}

.use-cases-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: var(--spacing-md);
    margin-top: var(--spacing-lg);
}

.use-case-card {
    background: white;
    padding: var(--spacing-lg);
    border-radius: var(--border-radius-md);
    border: 1px solid var(--color-border);
    transition: var(--transition);
    position: relative;
}

.use-case-card:hover {
    border-color: var(--color-primary-light);
    box-shadow: var(--shadow-2);
}

.use-case-card h3 {
    color: var(--color-text);
    margin-bottom: var(--spacing-sm);
}

.use-case-card p {
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-md);
}

.use-case-tag {
    display: inline-block;
    background: var(--color-primary);
    color: white;
    padding: 0.375rem 0.875rem;
    border-radius: 16px;
    font-size: 0.8125rem;
    font-weight: 500;
}

/* FAQ Section */
.faq {
    background: white;
}

.faq-list {
    max-width: 800px;
    margin: var(--spacing-lg) auto 0;
}

.faq-item {
    background: white;
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius-md);
    margin-bottom: var(--spacing-sm);
    overflow: hidden;
}

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

.faq-question:hover {
    background: var(--color-bg-alt);
}

.faq-icon {
    font-size: 1.25rem;
    color: var(--color-text-secondary);
    transition: var(--transition);
    font-weight: 300;
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    background: var(--color-bg-alt);
}

.faq-item.active .faq-icon {
    transform: rotate(45deg);
    background: var(--color-primary);
    color: white;
}

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

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

.faq-answer p {
    padding: 0 var(--spacing-md) var(--spacing-md);
    color: var(--color-text-secondary);
    margin-bottom: 0;
}

/* CTA Section - Google clean style */
.cta-section {
    background: var(--color-bg-alt);
    color: var(--color-text);
    text-align: center;
    border-top: 1px solid var(--color-border);
}

.cta-content h2 {
    color: var(--color-text);
    margin-bottom: var(--spacing-md);
}

.cta-content p {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-md);
    color: var(--color-text-secondary);
}

.cta-content .btn-large {
    background: var(--color-primary);
    color: white !important;
    margin: var(--spacing-md) 0;
}

.cta-content .btn-large:hover {
    background: var(--color-primary-dark);
    box-shadow: 0 1px 3px 0 rgba(60, 64, 67, 0.3), 0 4px 8px 3px rgba(60, 64, 67, 0.15);
}

.cta-note {
    font-size: 0.8125rem;
    color: var(--color-text-tertiary);
    margin-top: var(--spacing-md);
}

/* Footer - Google style */
.footer {
    background: var(--color-bg);
    color: var(--color-text);
    padding: var(--spacing-xl) 0 var(--spacing-lg);
    border-top: 1px solid var(--color-border);
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.footer-section h3 {
    color: var(--color-text);
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: var(--spacing-md);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.footer-section p {
    color: var(--color-text-secondary);
    line-height: 1.6;
    font-size: 0.875rem;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: var(--spacing-xs);
}

.footer-section a {
    color: var(--color-text-secondary);
    transition: var(--transition);
    font-size: 0.875rem;
}

.footer-section a:hover {
    color: var(--color-primary);
}

.footer-bottom {
    border-top: 1px solid var(--color-border);
    padding-top: var(--spacing-md);
    text-align: center;
}

.footer-bottom p {
    color: var(--color-text-tertiary);
    font-size: 0.8125rem;
    margin-bottom: var(--spacing-xs);
}

.footer-keywords {
    font-size: 0.75rem;
    color: var(--color-text-tertiary);
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-toggle {
        display: flex;
    }

    .nav-menu {
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: var(--spacing-md);
        border-top: 1px solid var(--color-border);
        box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
        transform: translateY(-100%);
        opacity: 0;
        pointer-events: none;
        transition: var(--transition);
    }

    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        pointer-events: all;
    }

    .hero-content {
        text-align: center;
    }

    .features-grid,
    .steps-grid,
    .use-cases-grid {
        grid-template-columns: 1fr;
    }

    .files-demo {
        flex-direction: column;
    }

    .arrow {
        transform: rotate(90deg);
    }

    .footer-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }
}

@media (max-width: 480px) {
    :root {
        --spacing-md: 1rem;
        --spacing-lg: 2rem;
        --spacing-xl: 3rem;
        --spacing-xxl: 4rem;
    }

    .container {
        padding: 0 var(--spacing-sm);
    }

    .btn-large {
        padding: 0.875rem 1.5rem;
        font-size: 0.875rem;
        width: 100%;
    }
    
    .section {
        padding: var(--spacing-xl) 0;
    }
    
    .hero {
        padding: var(--spacing-xl) 0 var(--spacing-lg);
    }
    
    .gradient-text {
        font-size: clamp(2rem, 8vw, 3rem);
    }
}

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

.fade-in {
    animation: fadeIn 0.6s ease forwards;
}

/* Accessibility */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}

/* Focus Styles */
a:focus,
button:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* Print Styles */
@media print {
    .header,
    .nav,
    .footer,
    .cta-section {
        display: none;
    }

    body {
        color: black;
    }

    a {
        color: black;
        text-decoration: underline;
    }
}