/* ============================================
   RESET & BASE STYLES
   ============================================ */

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

:root {
    /* Color Palette */
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --secondary-color: #64748b;
    --secondary-hover: #475569;
    --accent-color: #10b981;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-light: #94a3b8;
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    
    /* Typography */
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-mono: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas, monospace;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    --spacing-3xl: 6rem;
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    
    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-base: 250ms ease-in-out;
    --transition-slow: 350ms ease-in-out;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ============================================
   TYPOGRAPHY
   ============================================ */

h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    color: var(--text-primary);
    margin-bottom: var(--spacing-md);
}

h1 {
    font-size: clamp(2rem, 5vw, 3.5rem);
    margin-bottom: var(--spacing-lg);
}

h2 {
    font-size: clamp(1.75rem, 4vw, 2.5rem);
    margin-bottom: var(--spacing-md);
    text-align: center;
}

h3 {
    font-size: clamp(1.25rem, 3vw, 1.5rem);
    margin-bottom: var(--spacing-sm);
}

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

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

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

code {
    font-family: var(--font-mono);
    font-size: 0.9em;
    background-color: var(--bg-tertiary);
    padding: 0.2em 0.4em;
    border-radius: var(--radius-sm);
    color: var(--primary-color);
}

strong {
    font-weight: 600;
    color: var(--text-primary);
}

/* ============================================
   LAYOUT & CONTAINER
   ============================================ */

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

@media (min-width: 768px) {
    .container {
        padding: 0 var(--spacing-lg);
    }
}

/* ============================================
   BUTTONS
   ============================================ */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--radius-md);
    border: none;
    cursor: pointer;
    transition: all var(--transition-base);
    text-decoration: none;
    white-space: nowrap;
}

.btn-large {
    padding: 1rem 2rem;
    font-size: 1.125rem;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    background-color: var(--primary-hover);
    box-shadow: var(--shadow-lg);
    transform: translateY(-2px);
    color: white;
}

.btn-secondary {
    background-color: white;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

.btn-secondary:hover {
    background-color: var(--primary-color);
    color: white;
    transform: translateY(-2px);
}

.btn-help {
    background-color: var(--accent-color);
    color: white;
    box-shadow: var(--shadow-md);
}

.btn-help:hover {
    background-color: #059669;
    box-shadow: var(--shadow-lg);
    transform: translateY(-2px);
    color: white;
}

/* ============================================
   HERO SECTION
   ============================================ */

.hero {
    padding: var(--spacing-2xl) 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg width="100" height="100" xmlns="http://www.w3.org/2000/svg"><defs><pattern id="grid" width="100" height="100" patternUnits="userSpaceOnUse"><path d="M 100 0 L 0 0 0 100" fill="none" stroke="rgba(255,255,255,0.1)" stroke-width="1"/></pattern></defs><rect width="100" height="100" fill="url(%23grid)"/></svg>');
    opacity: 0.3;
}

.hero .container {
    position: relative;
    z-index: 1;
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-2xl);
    align-items: center;
}

@media (min-width: 968px) {
    .hero .container {
        grid-template-columns: 1fr 1fr;
    }
}

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

@media (min-width: 968px) {
    .hero-content {
        text-align: left;
    }
}

.hero h1 {
    color: white;
    margin-bottom: var(--spacing-md);
}

.hero-subtitle {
    font-size: clamp(1.25rem, 3vw, 1.75rem);
    font-weight: 600;
    color: rgba(255, 255, 255, 0.95);
    margin-bottom: var(--spacing-md);
}

.hero-description {
    font-size: clamp(1rem, 2vw, 1.125rem);
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: var(--spacing-xl);
    line-height: 1.7;
}

.cta-buttons {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-xl);
    align-items: center;
}

@media (min-width: 640px) {
    .cta-buttons {
        flex-direction: row;
        justify-content: center;
    }
}

@media (min-width: 968px) {
    .cta-buttons {
        justify-content: flex-start;
    }
}

.trust-indicators {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-md);
    justify-content: center;
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.9);
}

@media (min-width: 968px) {
    .trust-indicators {
        justify-content: flex-start;
    }
}

.trust-indicators span {
    display: flex;
    align-items: center;
}

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

.hero-image {
    width: 100%;
    max-width: 600px;
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: var(--shadow-xl);
}

.hero-image-placeholder {
    width: 100%;
    padding-bottom: 75%;
    position: relative;
    background: white;
    border-radius: var(--radius-xl);
}

.hero-image-placeholder svg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

/* ============================================
   SECTION STYLES
   ============================================ */

section {
    padding: var(--spacing-2xl) 0;
}

section:nth-child(even) {
    background-color: var(--bg-secondary);
}

.section-subtitle {
    text-align: center;
    font-size: clamp(1rem, 2vw, 1.25rem);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xl);
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

/* ============================================
   VIDEO TUTORIAL SECTION
   ============================================ */

.video-tutorial {
    background-color: var(--bg-primary);
}

.video-wrapper {
    margin-bottom: var(--spacing-xl);
}

.video-container {
    position: relative;
    padding-bottom: 56.25%; /* 16:9 aspect ratio */
    height: 0;
    overflow: hidden;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    background-color: var(--bg-tertiary);
}

.video-container iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border: none;
}

.video-features {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xl);
}

@media (min-width: 640px) {
    .video-features {
        grid-template-columns: repeat(3, 1fr);
    }
}

.feature-item {
    text-align: center;
    padding: var(--spacing-lg);
    background-color: var(--bg-primary);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.feature-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.feature-item .icon {
    font-size: 2.5rem;
    display: block;
    margin-bottom: var(--spacing-sm);
}

.feature-item h3 {
    margin-bottom: var(--spacing-xs);
}

.feature-item p {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* ============================================
   WHAT IS IT SECTION
   ============================================ */

.what-is-it {
    background-color: var(--bg-secondary);
}

.explanation {
    max-width: 900px;
    margin: 0 auto;
}

.lead {
    font-size: clamp(1.125rem, 2.5vw, 1.375rem);
    line-height: 1.8;
    color: var(--text-primary);
    margin-bottom: var(--spacing-xl);
    text-align: center;
}

.how-it-works {
    list-style: none;
    counter-reset: step-counter;
    max-width: 800px;
    margin: 0 auto;
}

.how-it-works li {
    counter-increment: step-counter;
    margin-bottom: var(--spacing-xl);
    padding-left: var(--spacing-2xl);
    position: relative;
}

.how-it-works li::before {
    content: counter(step-counter);
    position: absolute;
    left: 0;
    top: 0;
    width: 2.5rem;
    height: 2.5rem;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-hover));
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.25rem;
    box-shadow: var(--shadow-md);
}

.how-it-works li strong {
    display: block;
    font-size: 1.25rem;
    margin-bottom: var(--spacing-xs);
    color: var(--text-primary);
}

.how-it-works li p {
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ============================================
   FEATURES SECTION
   ============================================ */

.features {
    background-color: var(--bg-primary);
}

.features-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xl);
}

@media (min-width: 640px) {
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 968px) {
    .features-grid {
        grid-template-columns: repeat(4, 1fr);
    }
}

.feature-card {
    background-color: var(--bg-primary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    transition: all var(--transition-base);
    text-align: center;
}

.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-color);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-md);
    display: block;
}

.feature-card h3 {
    margin-bottom: var(--spacing-sm);
    font-size: 1.25rem;
}

.feature-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.6;
}

/* ============================================
   HOW TO USE SECTION
   ============================================ */

.how-to-use {
    background-color: var(--bg-secondary);
}

.steps {
    max-width: 900px;
    margin: 0 auto;
    margin-top: var(--spacing-xl);
}

.step {
    display: flex;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
    align-items: flex-start;
}

.step-number {
    flex-shrink: 0;
    width: 3rem;
    height: 3rem;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-hover));
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.5rem;
    box-shadow: var(--shadow-md);
}

.step-content {
    flex: 1;
    padding-top: 0.5rem;
}

.step-content h3 {
    margin-bottom: var(--spacing-xs);
    color: var(--text-primary);
}

.step-content p {
    color: var(--text-secondary);
    line-height: 1.7;
}

.step-content a {
    color: var(--primary-color);
    font-weight: 600;
}

/* ============================================
   USE CASES SECTION
   ============================================ */

.use-cases {
    background-color: var(--bg-primary);
}

.use-cases-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xl);
}

@media (min-width: 640px) {
    .use-cases-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

.use-case {
    background: linear-gradient(135deg, var(--bg-secondary), var(--bg-tertiary));
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    border-left: 4px solid var(--primary-color);
    transition: all var(--transition-base);
}

.use-case:hover {
    transform: translateX(4px);
    box-shadow: var(--shadow-md);
}

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

.use-case p {
    color: var(--text-secondary);
    font-style: italic;
    font-size: 0.95rem;
}

/* ============================================
   REQUIREMENTS SECTION
   ============================================ */

.requirements {
    background-color: var(--bg-secondary);
}

.requirements-list {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xl);
    margin-bottom: var(--spacing-2xl);
}

@media (min-width: 640px) {
    .requirements-list {
        grid-template-columns: repeat(2, 1fr);
    }
}

.requirement-item {
    background-color: var(--bg-primary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
}

.requirement-item strong {
    display: block;
    font-size: 1.125rem;
    margin-bottom: var(--spacing-xs);
    color: var(--text-primary);
}

.requirement-item p {
    color: var(--text-secondary);
    margin: 0;
}

.requirement-item a {
    color: var(--primary-color);
    font-weight: 600;
}

.cost-info {
    background-color: var(--bg-primary);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    border: 2px solid var(--accent-color);
    max-width: 800px;
    margin: 0 auto;
}

.cost-info h3 {
    color: var(--text-primary);
    margin-bottom: var(--spacing-md);
}

.cost-info p {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
}

.cost-info ul {
    list-style: none;
    padding-left: 0;
    margin-bottom: var(--spacing-md);
}

.cost-info ul li {
    padding: var(--spacing-xs) 0;
    padding-left: var(--spacing-lg);
    position: relative;
    color: var(--text-secondary);
}

.cost-info ul li::before {
    content: '→';
    position: absolute;
    left: 0;
    color: var(--accent-color);
    font-weight: 700;
}

/* ============================================
   DOWNLOAD SECTION
   ============================================ */

.download {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    position: relative;
    overflow: hidden;
}

.download::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg width="100" height="100" xmlns="http://www.w3.org/2000/svg"><defs><pattern id="grid" width="100" height="100" patternUnits="userSpaceOnUse"><path d="M 100 0 L 0 0 0 100" fill="none" stroke="rgba(255,255,255,0.1)" stroke-width="1"/></pattern></defs><rect width="100" height="100" fill="url(%23grid)"/></svg>');
    opacity: 0.3;
}

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

.download h2 {
    color: white;
}

.download .section-subtitle {
    color: rgba(255, 255, 255, 0.95);
}

.download-options {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xl);
    margin-bottom: var(--spacing-2xl);
}

@media (min-width: 768px) {
    .download-options {
        grid-template-columns: repeat(2, 1fr);
    }
}

.download-card {
    background-color: white;
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
    text-align: center;
    transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.download-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
}

.download-card.primary {
    border: 3px solid var(--accent-color);
}

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

.download-card p {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
}

.download-info {
    font-size: 0.875rem;
    color: var(--text-light);
    margin-top: var(--spacing-md);
    margin-bottom: 0;
}

.download-features {
    background-color: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    max-width: 700px;
    margin: 0 auto;
}

.download-features h3 {
    color: white;
    margin-bottom: var(--spacing-md);
    text-align: center;
}

.download-features ul {
    list-style: none;
    padding: 0;
    text-align: left;
    max-width: 500px;
    margin: 0 auto;
}

.download-features ul li {
    color: rgba(255, 255, 255, 0.95);
    padding: var(--spacing-xs) 0;
    font-size: 1.05rem;
}

/* ============================================
   FAQ SECTION
   ============================================ */

.faq {
    background-color: var(--bg-primary);
}

.faq-list {
    max-width: 900px;
    margin: 0 auto;
    margin-top: var(--spacing-xl);
}

.faq-item {
    background-color: var(--bg-secondary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    margin-bottom: var(--spacing-md);
    border: 1px solid var(--border-color);
    transition: all var(--transition-base);
}

.faq-item:hover {
    box-shadow: var(--shadow-md);
    border-color: var(--primary-color);
}

.faq-item h3 {
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
    font-size: 1.125rem;
}

.faq-item p {
    color: var(--text-secondary);
    line-height: 1.7;
    margin: 0;
}

.faq-item a {
    color: var(--primary-color);
    font-weight: 600;
}

.faq-item code {
    background-color: var(--bg-tertiary);
    color: var(--primary-color);
}

/* ============================================
   HELP SECTION
   ============================================ */

.help-section {
    background-color: var(--bg-secondary);
}

.help-card {
    max-width: 700px;
    margin: 0 auto;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-hover));
    padding: var(--spacing-2xl);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    text-align: center;
    color: white;
}

.help-card h2 {
    color: white;
    margin-bottom: var(--spacing-md);
}

.help-card p {
    color: rgba(255, 255, 255, 0.95);
    font-size: 1.125rem;
    margin-bottom: var(--spacing-lg);
    line-height: 1.7;
}

.help-note {
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.85);
    margin-top: var(--spacing-lg);
    margin-bottom: 0;
}

/* ============================================
   FOOTER
   ============================================ */

.footer {
    background-color: var(--text-primary);
    color: white;
    padding: var(--spacing-2xl) 0 var(--spacing-lg);
}

.footer-content {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

@media (min-width: 640px) {
    .footer-content {
        grid-template-columns: repeat(3, 1fr);
    }
}

.footer-section h3 {
    color: white;
    margin-bottom: var(--spacing-md);
    font-size: 1.125rem;
}

.footer-section ul {
    list-style: none;
    padding: 0;
}

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

.footer-section a {
    color: rgba(255, 255, 255, 0.8);
    transition: color var(--transition-fast);
}

.footer-section a:hover {
    color: white;
}

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-lg);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-bottom p {
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.9rem;
    margin: 0;
}

/* ============================================
   RESPONSIVE UTILITIES
   ============================================ */

@media (max-width: 639px) {
    .cta-buttons {
        width: 100%;
    }
    
    .cta-buttons .btn {
        width: 100%;
    }
    
    section {
        padding: var(--spacing-xl) 0;
    }
    
    .hero {
        padding: var(--spacing-xl) 0;
    }
}

/* ============================================
   ACCESSIBILITY
   ============================================ */

@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
    
    html {
        scroll-behavior: auto;
    }
}

/* Focus styles for keyboard navigation */
a:focus-visible,
button:focus-visible {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* ============================================
   PRINT STYLES
   ============================================ */

@media print {
    .hero,
    .download,
    .help-section {
        background: white !important;
        color: black !important;
    }
    
    .btn {
        display: none;
    }
}