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

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

/* Focus management */
.download-btn:focus,
.version-link:focus,
.footer-link:focus {
    outline: 2px solid #007AFF;
    outline-offset: 2px;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    .download-btn {
        border: 2px solid currentColor;
    }
    
    .use-case,
    .feature {
        border: 1px solid currentColor;
    }
}

/* Reduced motion support */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
    
    .rainbow-border {
        animation: none;
        background: linear-gradient(45deg, #ff1744, #ff9800, #ffeb3b, #4caf50, #2196f3, #9c27b0, #ff1744);
    }
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: #333;
    background: linear-gradient(135deg, #007AFF 0%, #0056CC 100%);
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
header {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    padding: 1rem 0;
}

/* Hero Logo */
.hero-logo {
    display: flex;
    align-items: center;
    justify-content: flex-start;
    gap: 16px;
    margin-bottom: 1rem;
}

.hero-logo-img {
    width: 60px;
    height: 60px;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

.hero-logo h1 {
    color: white;
    font-size: 2.5rem;
    font-weight: 700;
    margin: 0;
}

/* Hero Section */
.hero {
    padding: 4rem 0;
    color: white;
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.hero-text {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    text-align: left;
    gap: 1.5rem;
}

.hero-content h2 {
    font-size: 3rem;
    font-weight: 700;
    margin: 0;
    line-height: 1.2;
}

.hero-content p {
    font-size: 1.2rem;
    margin: 0;
    opacity: 0.9;
    line-height: 1.5;
}

.cta-section {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.download-btn {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    background: linear-gradient(135deg, #2c2c2c 0%, #1a1a1a 100%);
    color: white;
    padding: 16px 32px;
    border: none;
    border-radius: 12px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    width: fit-content;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
    position: relative;
}

.download-btn:hover {
    background: linear-gradient(135deg, #1a1a1a 0%, #000000 100%);
    transform: translateY(-2px);
    box-shadow: 0 6px 25px rgba(0, 0, 0, 0.4);
}

.system-req {
    font-size: 0.75rem;
    opacity: 0;
    margin-top: 0.4rem;
    transition: opacity 0.3s ease;
    color: rgba(255, 255, 255, 0.7);
    margin-bottom: 0;
}

.cta-section {
    position: relative;
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    margin-bottom: 2rem;
}

.download-btn:hover + .system-req {
    opacity: 1;
}

/* Version Subtitle Section */
.version-subtitle {
    margin-top: 1rem;
}

.version-text {
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.7);
}

.version-link {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    border-bottom: 1px solid rgba(255, 255, 255, 0.3);
    transition: all 0.3s ease;
}

.version-link:hover {
    color: white;
    border-bottom-color: rgba(255, 255, 255, 0.8);
}

/* Usage Steps */
.usage-steps {
    display: flex;
    align-items: center;
    justify-content: flex-start;
    gap: 1.5rem;
    margin: 0;
    flex-wrap: wrap;
}

.step {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    color: white;
}

.step-number {
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.2);
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.1rem;
}

.step p {
    margin: 0;
    font-size: 0.9rem;
    text-align: center;
    opacity: 0.9;
}

.step-arrow {
    color: rgba(255, 255, 255, 0.6);
    font-size: 1.5rem;
    font-weight: bold;
}

.usage-tagline {
    color: rgba(255, 255, 255, 0.8);
    font-size: 0.7rem;
    text-align: left;
    margin: 0;
    font-style: italic;
}

/* App Preview */
.app-preview {
    display: flex;
    justify-content: center;
}

.preview-window {
    background: rgba(255, 255, 255, 0.95);
    border-radius: 12px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
    overflow: hidden;
    max-width: 500px;
    width: 100%;
}

.window-controls {
    display: flex;
    gap: 8px;
    padding: 12px 16px;
    background: rgba(0, 0, 0, 0.05);
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
}

.control {
    width: 12px;
    height: 12px;
    border-radius: 50%;
}

.control.red { background: #ff5f57; }
.control.yellow { background: #ffbd2e; }
.control.green { background: #28ca42; }

.window-content {
    padding: 24px;
}

.explanation-demo {
    display: flex;
    flex-direction: column;
    gap: 16px;
    position: relative;
}

.selected-text {
    padding: 12px;
    background: rgba(0, 122, 255, 0.1);
    border: 1px solid rgba(0, 122, 255, 0.2);
    border-radius: 8px;
}

.highlight {
    background: rgba(0, 122, 255, 0.2);
    padding: 2px 4px;
    border-radius: 4px;
    color: #007AFF;
    font-weight: 600;
}

.explanation-box {
    padding: 16px;
    background: rgba(0, 0, 0, 0.02);
    border: 1px solid rgba(0, 0, 0, 0.1);
    border-radius: 8px;
}

.explanation-box p {
    color: #333;
    line-height: 1.5;
}

.thinking-mode {
    display: none;
    align-items: center;
    gap: 8px;
    padding: 12px 16px;
    background: rgba(0, 0, 0, 0.02);
    border: 1px solid rgba(0, 0, 0, 0.1);
    border-radius: 8px;
    font-size: 14px;
    color: #666;
}

.thinking-mode.active {
    display: flex;
}

.rainbow-border {
    position: relative;
    border-radius: 8px;
    background: linear-gradient(45deg, 
        #ff1744, #ff9800, #ffeb3b, #4caf50, 
        #2196f3, #9c27b0, #ff1744);
    background-size: 400% 400%;
    animation: rainbow-transform 3s ease-in-out infinite;
    padding: 2px;
    will-change: transform;
}

.rainbow-border .explanation-box {
    background: white;
    border: none;
    margin: 0;
}

@keyframes rainbow-transform {
    0%, 100% { 
        transform: rotate(0deg) scale(1);
        background-position: 0% 50%;
    }
    25% {
        background-position: 100% 0%;
    }
    50% { 
        transform: rotate(1deg) scale(1.02);
        background-position: 100% 50%;
    }
    75% {
        background-position: 0% 100%;
    }
}

.spinner {
    width: 14px;
    height: 14px;
    border: 2px solid #ddd;
    border-top: 2px solid #007AFF;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Use Cases Section */
.use-cases {
    background: white;
    padding: 4rem 0;
}

.use-cases h3 {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: #333;
}

.use-cases-subtitle {
    text-align: center;
    font-size: 1.2rem;
    color: #666;
    margin-bottom: 3rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.use-cases-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.use-case {
    text-align: center;
    padding: 2rem;
    border-radius: 16px;
    background: rgba(0, 122, 255, 0.02);
    border: 1px solid rgba(0, 122, 255, 0.08);
    transition: all 0.3s ease;
}

.use-case:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 25px rgba(0, 122, 255, 0.1);
    border-color: rgba(0, 122, 255, 0.15);
}

.use-case-icon {
    width: 60px;
    height: 60px;
    margin: 0 auto 1.5rem auto;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(0, 122, 255, 0.1);
    border-radius: 12px;
}

.use-case-icon img {
    width: 40px;
    height: 40px;
}

.use-case h4 {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: #333;
}

.use-case p {
    color: #666;
    line-height: 1.5;
    margin: 0;
}

/* Features Section */
.features {
    background: #f8f9fa;
    padding: 4rem 0;
}

.features h3 {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: #333;
}

.features-subtitle {
    text-align: center;
    font-size: 1.2rem;
    color: #666;
    margin-bottom: 3rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.feature {
    text-align: center;
    padding: 2rem;
    border-radius: 16px;
    background: rgba(0, 122, 255, 0.02);
    border: 1px solid rgba(0, 122, 255, 0.08);
    transition: all 0.3s ease;
}

.feature:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 25px rgba(0, 122, 255, 0.1);
    border-color: rgba(0, 122, 255, 0.15);
}

.feature-icon {
    width: 60px;
    height: 60px;
    margin: 0 auto 1.5rem auto;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(0, 122, 255, 0.1);
    border-radius: 12px;
}

.feature-icon img {
    width: 40px;
    height: 40px;
}

.feature h4 {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: #333;
}

.feature p {
    color: #666;
    line-height: 1.5;
    margin: 0;
}

/* Footer */
footer {
    background: rgba(0, 0, 0, 0.1);
    backdrop-filter: blur(20px);
    color: white;
    text-align: center;
    padding: 2rem 0;
}

.footer-links {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1rem;
}

.footer-link {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s ease;
    padding: 0.25rem 0.5rem;
    border-radius: 6px;
}

.footer-link:hover {
    color: white;
    background: rgba(255, 255, 255, 0.1);
}

.footer-separator {
    color: rgba(255, 255, 255, 0.5);
    font-weight: 300;
}

footer p {
    opacity: 0.8;
    margin: 0.5rem 0;
}

.developer-credit {
    font-size: 0.9rem;
    margin-top: 0.5rem;
}

/* Mobile Responsiveness */
@media (max-width: 768px) {
    .hero-content {
        grid-template-columns: 1fr;
        gap: 2rem;
        text-align: center;
    }
    
    .hero-text {
        align-items: center;
        text-align: center;
    }
    
    .hero-logo {
        justify-content: center;
    }
    
    .usage-steps {
        justify-content: center;
    }
    
    .usage-tagline {
        text-align: center;
    }
    
    .hero-content h2 {
        font-size: 2.2rem;
    }
    
    .hero-logo h1 {
        font-size: 2rem;
    }
    
    .hero-logo-img {
        width: 50px;
        height: 50px;
    }
    
    .usage-steps {
        gap: 1rem;
    }
    
    .step-arrow {
        display: none;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .use-cases-grid {
        grid-template-columns: 1fr;
    }
    
    .container {
        padding: 0 16px;
    }
    
    .preview-window {
        max-width: 100%;
        margin: 0 16px;
    }
    
    .footer-links {
        flex-direction: column;
        gap: 0.5rem;
    }
    
    .footer-separator {
        display: none;
    }
}
    
    .preview-window {
        max-width: 100%;
        margin: 0 16px;
    }
    
    .version-subtitle {
        text-align: center;
    }


@media (max-width: 480px) {
    .hero {
        padding: 2rem 0;
    }
    
    .hero-content h2 {
        font-size: 1.8rem;
    }
    
    .hero-content p {
        font-size: 1rem;
    }
    
    .hero-logo {
        gap: 12px;
    }
    
    .hero-logo h1 {
        font-size: 1.6rem;
    }
    
    .hero-logo-img {
        width: 40px;
        height: 40px;
    }
    
    .usage-steps {
        flex-direction: column;
        gap: 1.5rem;
    }
    
    .download-btn {
        padding: 14px 24px;
        font-size: 1rem;
    }
    
    .features, .use-cases {
        padding: 2rem 0;
    }
    
    .features h3, .use-cases h3 {
        font-size: 2rem;
        margin-bottom: 2rem;
    }
    
    .version-subtitle {
        margin-top: 0.75rem;
    }
    
    .version-text {
        font-size: 0.8rem;
    }
}