:root {
    --primary: #5DBCC3;
    --primary-dark: #4A9CA2;
    --primary-light: #7FD4DA;
    --accent: #FF8B94;
    --dark: #2C3E50;
    --light: #F8F9FA;
    --gray: #6C757D;
    --border: #E5E7EB;
    --shadow: 0 2px 8px rgba(0,0,0,0.1);
    --shadow-lg: 0 8px 24px rgba(0,0,0,0.15);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--dark);
    background: #F5F7F9;
}

/* Skip to content link for accessibility */
.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--primary);
    color: white;
    padding: 0.5rem 1rem;
    text-decoration: none;
    z-index: 200;
    border-radius: 0 0 4px 0;
}

.skip-link:focus {
    top: 0;
}

/* Focus styles for keyboard navigation */
a:focus,
button:focus,
summary:focus,
details:focus,
input:focus,
textarea:focus,
select:focus {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

/* Navigation */
.navbar {
    background: white;
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    text-decoration: none;
    color: var(--dark);
    font-size: 1.5rem;
    font-weight: 600;
}

.nav-icon {
    width: 40px;
    height: 40px;
}

.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-links a {
    color: var(--gray);
    text-decoration: none;
    transition: color 0.3s;
}

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

/* Hero Section */
.hero {
    padding: 3rem 2rem 4rem;
    background: linear-gradient(180deg, #FAFBFC 0%, #F5F7F9 100%);
    text-align: center;
    border-bottom: 1px solid var(--border);
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
}

.hero-mascot {
    width: 200px;
    height: 200px;
    margin-bottom: 2rem;
    filter: drop-shadow(0 4px 20px rgba(93, 188, 195, 0.25));
    animation: float 3s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    color: var(--dark);
}

.hero-subtitle {
    font-size: 1.15rem;
    margin-bottom: 2.5rem;
    color: var(--gray);
}

.download-section {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

.btn-primary {
    display: inline-flex;
    align-items: center;
    gap: 0.75rem;
    background: var(--primary);
    color: white;
    padding: 0.875rem 2rem;
    border-radius: 6px;
    text-decoration: none;
    font-size: 1rem;
    font-weight: 500;
    transition: background 0.3s;
}

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

.download-icon {
    width: 24px;
    height: 24px;
}

.version-info {
    font-size: 0.9rem;
    color: var(--gray);
}

.platform-note {
    color: var(--primary);
    font-style: italic;
}

.alt-downloads {
    color: var(--gray);
    font-size: 0.9rem;
    transition: color 0.3s;
}

.alt-downloads:hover {
    color: var(--primary);
}

/* Trust Signals */
.trust-signals {
    margin-top: 1rem;
    display: flex;
    gap: 1.5rem;
    justify-content: center;
    align-items: center;
    font-size: 0.9rem;
}

.changelog-link {
    color: var(--primary);
    text-decoration: none;
    transition: opacity 0.3s;
}

.changelog-link:hover {
    opacity: 0.8;
    text-decoration: underline;
}

.checksum-details {
    color: var(--gray);
}

.checksum-details summary {
    cursor: pointer;
    color: var(--primary);
    user-select: none;
    transition: opacity 0.3s;
}

.checksum-details summary:hover {
    opacity: 0.8;
}

.checksum-details[open] summary {
    margin-bottom: 0.5rem;
}

.checksum {
    display: block;
    margin-top: 0.5rem;
    padding: 0.5rem;
    background: rgba(0, 0, 0, 0.05);
    border-radius: 4px;
    font-family: 'Courier New', monospace;
    font-size: 0.85rem;
    word-break: break-all;
    color: var(--dark);
}

.checksum-note {
    margin-top: 0.5rem;
    font-size: 0.85rem;
    color: var(--gray);
}

/* Features Section */
.features {
    padding: 4rem 2rem;
    background: #FAFBFC;
}

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

.features h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: var(--dark);
}

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

.features-subtitle {
    text-align: center;
    font-size: 1.2rem;
    color: var(--gray);
    margin-bottom: 3rem;
    margin-top: -1rem;
}

.feature-card {
    padding: 1.5rem;
    background: white;
    border: 1px solid #E2E8F0;
    border-radius: 8px;
    transition: all 0.3s;
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
}

.feature-card:hover {
    border-color: var(--primary);
    box-shadow: 0 4px 12px rgba(93, 188, 195, 0.15);
    transform: translateY(-2px);
}

.feature-card h3 {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
    color: var(--dark);
}

.feature-card p {
    color: var(--gray);
    line-height: 1.5;
    font-size: 0.95rem;
}

/* Demo Video Section */
.demo-video {
    padding: 4rem 2rem;
    background: #FFFFFF;
    text-align: center;
}

.demo-video h2 {
    font-size: 2rem;
    margin-bottom: 0.5rem;
    color: var(--dark);
}

.demo-subtitle {
    color: var(--muted);
    font-size: 1.125rem;
    margin-bottom: 2rem;
}

.video-container {
    max-width: 900px;
    margin: 0 auto 1.5rem;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    border: 1px solid #E2E8F0;
    background: #000;
}

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

.video-caption {
    color: var(--muted);
    font-size: 0.95rem;
    font-style: italic;
}

/* CTA Section */
.cta {
    padding: 3rem 2rem;
    background: linear-gradient(180deg, #F5F7F9 0%, #EDF2F7 100%);
    text-align: center;
    border-top: 1px solid #E2E8F0;
}

.cta h2 {
    font-size: 2rem;
    margin-bottom: 0.75rem;
    color: var(--dark);
}

.cta p {
    font-size: 1.1rem;
    margin-bottom: 2rem;
    color: var(--gray);
}

.cta-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    align-items: center;
    flex-wrap: wrap;
}

.btn-secondary {
    display: inline-block;
    background: var(--dark);
    color: white;
    padding: 0.75rem 1.75rem;
    border-radius: 6px;
    text-decoration: none;
    font-weight: 500;
    transition: opacity 0.3s;
}

.btn-secondary:hover {
    opacity: 0.9;
}

.btn-discord {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: #5865F2;
    color: white;
    padding: 0.75rem 1.75rem;
    border-radius: 6px;
    text-decoration: none;
    font-weight: 500;
    transition: opacity 0.3s;
}

.btn-discord:hover {
    opacity: 0.9;
}

/* Footer */
footer {
    background: var(--dark);
    color: white;
    padding: 3rem 2rem 1.5rem;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 3rem;
    margin-bottom: 2rem;
}

.footer-brand {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
}

.footer-brand h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: white;
}

.footer-section h4 {
    margin-bottom: 1rem;
    color: var(--primary-light);
}

.footer-section a {
    display: block;
    color: rgba(255,255,255,0.7);
    text-decoration: none;
    margin-bottom: 0.5rem;
    transition: color 0.3s;
}

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

.footer-logo {
    width: 80px;
    height: 80px;
    margin-bottom: 1rem;
    filter: drop-shadow(0 2px 8px rgba(0,0,0,0.3));
}

.footer-bottom {
    border-top: 1px solid rgba(255,255,255,0.1);
    padding-top: 1.5rem;
    text-align: center;
    color: rgba(255,255,255,0.6);
    font-size: 0.9rem;
}

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

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

/* Return to Top Button */
#return-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 48px;
    height: 48px;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
    opacity: 0;
    visibility: hidden;
    z-index: 99;
}

#return-to-top:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(93, 188, 195, 0.4);
}

#return-to-top:active {
    transform: translateY(0);
}

#return-to-top.visible {
    opacity: 1;
    visibility: visible;
}

/* Smooth scroll behavior */
html {
    scroll-behavior: smooth;
}

/* Responsive */
@media (max-width: 1024px) {
    .footer-content {
        grid-template-columns: 1fr 1fr;
    }
    
    .footer-brand {
        grid-column: 1 / -1;
    }
}

@media (max-width: 768px) {
    /* Navigation */
    .nav-container {
        padding: 1rem;
    }
    
    .nav-links {
        gap: 0.5rem;
        font-size: 0.85rem;
    }
    
    .nav-links a {
        padding: 0.4rem 0.6rem;
    }
    
    .nav-cta {
        padding: 0.4rem 0.8rem !important;
        font-size: 0.85rem;
    }
    
    /* Hero Section */
    .hero {
        padding: 3rem 1rem 4rem;
    }
    
    .hero h1 {
        font-size: 2.5rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
        margin-bottom: 1.5rem;
    }
    
    .hero-mascot {
        width: 120px;
        height: 120px;
    }
    
    .download-section {
        margin-top: 1.5rem;
    }
    
    .btn-primary {
        padding: 0.875rem 1.5rem;
        font-size: 1rem;
    }
    
    .version-info {
        font-size: 0.85rem;
    }
    
    .trust-signals {
        flex-direction: column;
        gap: 0.75rem;
        margin-top: 0.75rem;
    }
    
    /* Features Section */
    .features {
        padding: 3rem 1rem;
    }
    
    .features h2 {
        font-size: 1.75rem;
        margin-bottom: 0.5rem;
    }
    
    .features-subtitle {
        font-size: 0.95rem;
        margin-bottom: 2rem;
    }
    
    .feature-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .feature-card {
        padding: 1.25rem;
    }
    
    .feature-card h3 {
        font-size: 1.1rem;
    }
    
    .feature-card p {
        font-size: 0.95rem;
    }
    
    /* Demo Video Section */
    .demo-video {
        padding: 3rem 1rem;
    }

    .demo-video h2 {
        font-size: 1.75rem;
    }

    .demo-subtitle {
        font-size: 1rem;
        margin-bottom: 1.5rem;
    }

    .video-container {
        margin: 0 auto 1rem;
    }

    .video-caption {
        font-size: 0.875rem;
    }

    /* CTA Section */
    .cta {
        padding: 3rem 1rem;
    }
    
    .cta h2 {
        font-size: 1.75rem;
    }
    
    .cta p {
        font-size: 1rem;
    }
    
    .cta-buttons {
        flex-direction: column;
        gap: 1rem;
        width: 100%;
        max-width: 300px;
        margin: 0 auto;
    }
    
    .btn-secondary,
    .btn-discord {
        width: 100%;
        justify-content: center;
    }
    
    /* Footer */
    footer {
        padding: 2rem 1rem 1rem;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 2rem;
    }
    
    .footer-brand {
        align-items: center;
    }
    
    .footer-section {
        display: flex;
        flex-direction: column;
        gap: 0.5rem;
    }
    
    .footer-bottom {
        flex-direction: column;
        gap: 0.5rem;
        font-size: 0.85rem;
        text-align: center;
    }
    
    /* Return to top button */
    #return-to-top {
        bottom: 1rem;
        right: 1rem;
        width: 40px;
        height: 40px;
    }
    
    #return-to-top svg {
        width: 20px;
        height: 20px;
    }
}

@media (max-width: 480px) {
    /* Very small mobile optimizations */
    .nav-logo span {
        font-size: 1rem;
    }
    
    .nav-icon {
        width: 28px;
        height: 28px;
    }
    
    .nav-links {
        gap: 0.3rem;
        font-size: 0.8rem;
    }
    
    .nav-links a {
        padding: 0.3rem 0.4rem;
    }
    
    .nav-cta {
        padding: 0.35rem 0.6rem !important;
        font-size: 0.8rem;
    }
    
    .hero h1 {
        font-size: 2rem;
    }
    
    .hero-mascot {
        width: 100px;
        height: 100px;
    }
    
    .btn-primary {
        padding: 0.75rem 1.25rem;
        font-size: 0.95rem;
    }
    
    .features h2 {
        font-size: 1.5rem;
    }
    
    .cta h2 {
        font-size: 1.5rem;
    }
}
}