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

:root {
    --color-bg: #151519;
    --color-surface: rgba(255, 255, 255, 0.06);
    --color-border: rgba(255, 255, 255, 0.12);
    --color-text: #ffffff;
    --color-text-muted: rgba(255, 255, 255, 0.5);
    --color-accent: #5CADB6;
    --color-accent-hover: #74c2ca;
    --color-danger: #ED1832;
    --radius: 12px;
    --max-width: 1080px;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
}

/* Nav */

header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: rgba(21, 21, 25, 0.8);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--color-border);
}

nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}

.logo {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-text);
    text-decoration: none;
}

.nav-links {
    display: flex;
    gap: 32px;
}

.nav-links a {
    color: var(--color-text-muted);
    text-decoration: none;
    font-size: 0.9rem;
    transition: color 0.2s;
}

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

/* Hero */

.hero {
    padding: 160px 0 100px;
    text-align: center;
}

.hero h1 {
    font-size: clamp(2.5rem, 6vw, 4rem);
    font-weight: 800;
    line-height: 1.1;
    letter-spacing: -0.02em;
    margin-bottom: 24px;
}

.subtitle {
    font-size: 1.2rem;
    color: var(--color-text-muted);
    max-width: 520px;
    margin: 0 auto 40px;
}

.cta-buttons {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

.store-badge {
    height: 48px;
    display: block;
}

/* Buttons */

.btn {
    display: inline-block;
    text-decoration: none;
    border-radius: var(--radius);
    transition: all 0.2s;
}

.btn-primary {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    padding: 8px 16px;
}

.btn-primary:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.2);
}

.btn-secondary {
    color: var(--color-accent);
    padding: 12px 32px;
    border: 1px solid var(--color-accent);
    border-radius: var(--radius);
    font-size: 1rem;
}

.btn-secondary:hover {
    background: rgba(92, 173, 182, 0.1);
}

/* Features */

.features {
    padding: 100px 0;
}

.features h2,
.programs h2,
.download h2,
.contact h2 {
    text-align: center;
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 16px;
}

.section-subtitle {
    text-align: center;
    color: var(--color-text-muted);
    max-width: 520px;
    margin: 0 auto;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 24px;
    margin-top: 48px;
}

.feature-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    padding: 32px 24px;
}

.feature-icon {
    font-size: 2rem;
    display: block;
    margin-bottom: 16px;
}

.feature-card h3 {
    font-size: 1.1rem;
    margin-bottom: 8px;
}

.feature-card p {
    color: var(--color-text-muted);
    font-size: 0.95rem;
}

/* Programs */

.programs {
    padding: 80px 0;
}

.program-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 24px;
    margin-top: 48px;
}

.program-category {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    padding: 32px 24px;
}

.program-category h3 {
    font-size: 1.1rem;
    margin-bottom: 16px;
    color: var(--color-accent);
}

.program-category ul {
    list-style: none;
    padding: 0;
}

.program-category li {
    color: var(--color-text-muted);
    font-size: 0.95rem;
    padding: 6px 0;
    border-bottom: 1px solid var(--color-border);
}

.program-category li:last-child {
    border-bottom: none;
}

/* Download */

.download {
    padding: 80px 0;
    text-align: center;
}

.download p {
    color: var(--color-text-muted);
    margin-bottom: 32px;
}

/* Contact */

.contact {
    padding: 80px 0;
    text-align: center;
}

.contact p {
    color: var(--color-text-muted);
    margin-bottom: 24px;
}

/* Footer */

footer {
    border-top: 1px solid var(--color-border);
    padding: 32px 0;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 16px;
}

.footer-content p {
    color: var(--color-text-muted);
    font-size: 0.85rem;
}

.footer-links {
    display: flex;
    gap: 24px;
}

.footer-links a {
    color: var(--color-text-muted);
    text-decoration: none;
    font-size: 0.85rem;
    transition: color 0.2s;
}

.footer-links a:hover {
    color: var(--color-text);
}

/* Mobile overlay (dim left side, tap to close) */

.mobile-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 9998;
    opacity: 0;
    transition: opacity 0.35s ease;
    pointer-events: none;
}

.mobile-overlay.open {
    opacity: 1;
    pointer-events: auto;
}

/* Mobile menu (lives outside header to avoid stacking context issues) */

.mobile-menu {
    display: none;
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    width: 75%;
    max-width: 320px;
    background: var(--color-bg);
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 40px;
    z-index: 9999;
    transform: translateX(100%);
    transition: transform 0.35s ease;
    border-left: 1px solid var(--color-border);
}

.mobile-menu.open {
    transform: translateX(0);
}

.mobile-menu-close {
    position: absolute;
    top: 16px;
    right: 20px;
    background: none;
    border: none;
    color: var(--color-text);
    font-size: 2rem;
    cursor: pointer;
    padding: 8px;
    line-height: 1;
}

.mobile-menu a {
    font-size: 1.25rem;
    color: var(--color-text);
    text-decoration: none;
    transition: color 0.2s;
}

.mobile-menu a:hover {
    color: var(--color-accent);
}

/* Menu toggle */

.menu-toggle {
    display: none;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    z-index: 10000;
    position: relative;
}

.menu-toggle span {
    display: block;
    width: 22px;
    height: 2px;
    background: var(--color-text);
    border-radius: 2px;
    transition: all 0.3s;
}

.menu-toggle[aria-expanded="true"] span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.menu-toggle[aria-expanded="true"] span:nth-child(2) {
    opacity: 0;
}

.menu-toggle[aria-expanded="true"] span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

/* Mobile */

@media (max-width: 640px) {
    .menu-toggle {
        display: flex;
    }

    .nav-links--desktop {
        display: none;
    }

    .mobile-menu {
        display: flex;
    }

    .mobile-overlay {
        display: block;
    }

    .hero {
        padding: 120px 0 60px;
    }

    .feature-grid {
        grid-template-columns: 1fr;
    }

    .program-grid {
        grid-template-columns: 1fr;
    }

    .footer-content {
        flex-direction: column;
        text-align: center;
    }
}