:root {
    --color-primary: #4F46E5;
    --color-primary-dark: #4338CA;
    --color-primary-light: #818CF8;
    --color-primary-bg: #EEF2FF;
    --color-text: #1F2937;
    --color-text-secondary: #6B7280;
    --color-text-light: #9CA3AF;
    --color-bg: #FFFFFF;
    --color-bg-alt: #F9FAFB;
    --color-border: #E5E7EB;
    --color-success: #10B981;
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --shadow-sm: 0 1px 2px 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);
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --transition: 0.2s ease;
}

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

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
}

body {
    font-family: var(--font-sans);
    color: var(--color-text);
    background: var(--color-bg);
    line-height: 1.6;
}

.container {
    max-width: 1140px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ---- Nav ---- */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--color-border);
}

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

.nav__logo {
    display: flex;
    align-items: center;
    gap: 8px;
    text-decoration: none;
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--color-text);
}

.nav__logo-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    background: var(--color-primary);
    color: white;
    border-radius: var(--radius-sm);
    font-size: 1.1rem;
    font-weight: 800;
}

.nav__links {
    display: flex;
    list-style: none;
    gap: 32px;
}

.nav__links a {
    text-decoration: none;
    color: var(--color-text-secondary);
    font-size: 0.925rem;
    font-weight: 500;
    transition: color var(--transition);
}

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

.nav__toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}

.nav__toggle span {
    width: 22px;
    height: 2px;
    background: var(--color-text);
    border-radius: 2px;
    transition: var(--transition);
}

/* ---- Buttons ---- */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    border-radius: var(--radius-sm);
    font-size: 0.925rem;
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    transition: all var(--transition);
    border: 2px solid transparent;
    line-height: 1.4;
}

.btn__icon {
    width: 18px;
    height: 18px;
}

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

.btn--primary:hover {
    background: var(--color-primary-dark);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn--outline {
    border-color: var(--color-border);
    color: var(--color-text);
    background: transparent;
}

.btn--outline:hover {
    border-color: var(--color-primary);
    color: var(--color-primary);
}

.btn--ghost {
    color: var(--color-text-secondary);
    background: transparent;
}

.btn--ghost:hover {
    color: var(--color-primary);
    background: var(--color-primary-bg);
}

.btn--sm {
    padding: 6px 14px;
    font-size: 0.85rem;
}

.btn--lg {
    padding: 14px 28px;
    font-size: 1rem;
}

/* ---- Section shared ---- */
.section__title {
    font-size: 2rem;
    font-weight: 800;
    text-align: center;
    margin-bottom: 8px;
}

.section__subtitle {
    text-align: center;
    color: var(--color-text-secondary);
    font-size: 1.1rem;
    margin-bottom: 48px;
}

/* ---- Hero ---- */
.hero {
    padding: 140px 0 100px;
    text-align: center;
    background: linear-gradient(180deg, var(--color-primary-bg) 0%, var(--color-bg) 100%);
}

.hero__title {
    font-size: clamp(2.25rem, 5vw, 3.5rem);
    font-weight: 800;
    line-height: 1.15;
    margin-bottom: 20px;
    max-width: 720px;
    margin-left: auto;
    margin-right: auto;
}

.hero__highlight {
    color: var(--color-primary);
}

.hero__subtitle {
    font-size: 1.2rem;
    color: var(--color-text-secondary);
    max-width: 560px;
    margin: 0 auto 36px;
    line-height: 1.7;
}

.hero__actions {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 24px;
}

.hero__trust {
    font-size: 0.875rem;
    color: var(--color-text-light);
}

/* ---- Features ---- */
.features {
    padding: 100px 0;
}

.features__grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
}

.feature-card {
    padding: 32px 28px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    transition: all var(--transition);
}

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

.feature-card__icon {
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-primary-bg);
    border-radius: var(--radius-sm);
    margin-bottom: 16px;
}

.feature-card__icon svg {
    width: 22px;
    height: 22px;
    color: var(--color-primary);
}

.feature-card__title {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.feature-card__text {
    color: var(--color-text-secondary);
    font-size: 0.925rem;
    line-height: 1.65;
}

/* ---- How It Works ---- */
.how-it-works {
    padding: 100px 0;
    background: var(--color-bg-alt);
}

.steps {
    display: flex;
    align-items: flex-start;
    justify-content: center;
    gap: 0;
}

.step {
    text-align: center;
    max-width: 260px;
    padding: 0 20px;
}

.step__number {
    width: 52px;
    height: 52px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-primary);
    color: white;
    border-radius: 50%;
    font-size: 1.25rem;
    font-weight: 800;
    margin: 0 auto 16px;
}

.step__title {
    font-size: 1.15rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.step__text {
    color: var(--color-text-secondary);
    font-size: 0.925rem;
    line-height: 1.65;
}

.step__connector {
    width: 60px;
    height: 2px;
    background: var(--color-border);
    margin-top: 26px;
    flex-shrink: 0;
}

/* ---- Install ---- */
.install {
    padding: 100px 0;
}

.install__card {
    text-align: center;
    padding: 60px 40px;
    background: linear-gradient(135deg, var(--color-primary-bg) 0%, #E0E7FF 100%);
    border-radius: var(--radius-lg);
}

.install__title {
    font-size: 2rem;
    font-weight: 800;
    margin-bottom: 8px;
}

.install__subtitle {
    color: var(--color-text-secondary);
    font-size: 1.1rem;
    margin-bottom: 40px;
}

.install__browsers {
    display: flex;
    gap: 20px;
    justify-content: center;
    flex-wrap: wrap;
}

.install__browser {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    padding: 24px 36px;
    background: white;
    border-radius: var(--radius-md);
    text-decoration: none;
    color: var(--color-text);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition);
    border: 2px solid transparent;
}

.install__browser:hover {
    border-color: var(--color-primary);
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.install__browser--coming-soon {
    opacity: 0.6;
    cursor: default;
}

.install__browser--coming-soon:hover {
    border-color: transparent;
    box-shadow: var(--shadow-sm);
    transform: none;
}

.install__browser-icon {
    width: 40px;
    height: 40px;
    color: var(--color-text-secondary);
}

.install__browser-name {
    font-weight: 600;
    font-size: 1rem;
}

.install__browser-status {
    font-size: 0.8rem;
    color: var(--color-success);
    font-weight: 600;
}

.install__browser--coming-soon .install__browser-status {
    color: var(--color-text-light);
}

/* ---- Open Source ---- */
.open-source {
    padding: 100px 0;
    background: var(--color-bg-alt);
}

.open-source__content {
    max-width: 640px;
    margin: 0 auto;
    text-align: center;
}

.open-source__text {
    color: var(--color-text-secondary);
    font-size: 1.1rem;
    line-height: 1.75;
    margin-bottom: 32px;
}

.open-source__actions {
    display: flex;
    gap: 12px;
    justify-content: center;
}

/* ---- Footer ---- */
.footer {
    padding: 60px 0 40px;
    border-top: 1px solid var(--color-border);
}

.footer__grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 48px;
}

.footer__tagline {
    color: var(--color-text-secondary);
    font-size: 0.925rem;
    margin-top: 12px;
}

.footer__links h4 {
    font-size: 0.85rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-light);
    margin-bottom: 16px;
}

.footer__links ul {
    list-style: none;
}

.footer__links li + li {
    margin-top: 10px;
}

.footer__links a {
    text-decoration: none;
    color: var(--color-text-secondary);
    font-size: 0.925rem;
    transition: color var(--transition);
}

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

.footer__bottom {
    border-top: 1px solid var(--color-border);
    padding-top: 24px;
    text-align: center;
}

.footer__bottom p {
    color: var(--color-text-light);
    font-size: 0.85rem;
}

/* ---- Responsive ---- */
@media (max-width: 768px) {
    .nav__links,
    .nav .btn {
        display: none;
    }

    .nav__toggle {
        display: flex;
    }

    .nav.nav--open .nav__links {
        display: flex;
        flex-direction: column;
        position: absolute;
        top: 64px;
        left: 0;
        right: 0;
        background: white;
        padding: 20px 24px;
        border-bottom: 1px solid var(--color-border);
        gap: 16px;
    }

    .features__grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }

    .steps {
        flex-direction: column;
        align-items: center;
    }

    .step__connector {
        width: 2px;
        height: 32px;
        margin: 8px auto;
    }

    .footer__grid {
        grid-template-columns: 1fr 1fr;
        gap: 32px;
    }

    .footer__brand {
        grid-column: span 2;
    }

    .hero__title {
        font-size: 2rem;
    }
}

@media (max-width: 480px) {
    .hero__actions {
        flex-direction: column;
        align-items: center;
    }

    .install__browsers {
        flex-direction: column;
        align-items: center;
    }

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

    .footer__brand {
        grid-column: span 1;
    }
}