:root {
    --blue: #1877f2;
    --blue-dark: #166fe0;
    --blue-soft: #e7f3ff;
    --text: #1c1e21;
    --text-muted: #65676b;
    --bg: #f0f2f5;
    --surface: #ffffff;
    --border: #dddfe2;
    --shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.12);
    --radius: 12px;
    --radius-sm: 8px;
    --max-width: 1120px;
    --font: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

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

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    font-family: var(--font);
    font-size: 16px;
    line-height: 1.6;
    color: var(--text);
    background: var(--bg);
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

a {
    color: var(--blue);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

.container {
    width: min(100% - 2rem, var(--max-width));
    margin-inline: auto;
}

.logo {
    font-size: 1.35rem;
    font-weight: 700;
    color: var(--blue);
    letter-spacing: -0.02em;
}

.logo--footer {
    display: block;
    margin-bottom: 0.35rem;
}

.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
}

.site-header__inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    min-height: 56px;
}

.site-nav {
    display: flex;
    align-items: center;
    gap: 0.75rem 1.25rem;
    flex-wrap: wrap;
    justify-content: flex-end;
}

.site-nav__link {
    font-size: 0.9375rem;
    font-weight: 600;
    color: var(--text);
    text-decoration: none;
}

.site-nav__link:hover {
    color: var(--blue);
    text-decoration: none;
}

.lang-switch {
    display: inline-flex;
    padding: 3px;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 999px;
}

.lang-switch__btn {
    padding: 0.3rem 0.75rem;
    font-size: 0.8125rem;
    font-weight: 600;
    color: var(--text-muted);
    border-radius: 999px;
    text-decoration: none;
}

.lang-switch__btn:hover {
    color: var(--text);
    text-decoration: none;
}

.lang-switch__btn.is-active {
    background: var(--surface);
    color: var(--blue);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
}

.hero {
    padding: 3rem 0 4rem;
}

.hero__grid {
    display: grid;
    gap: 2.5rem;
    align-items: center;
}

.hero__copy h1 {
    margin: 0.75rem 0 1rem;
    font-size: clamp(1.85rem, 4vw, 2.75rem);
    line-height: 1.15;
    letter-spacing: -0.03em;
}

.lead {
    margin: 0;
    font-size: 1.125rem;
    color: var(--text-muted);
    max-width: 54ch;
}

.badge {
    display: inline-block;
    margin: 0;
    padding: 0.35rem 0.75rem;
    font-size: 0.8125rem;
    font-weight: 700;
    letter-spacing: 0.02em;
    text-transform: uppercase;
    color: var(--blue);
    background: var(--blue-soft);
    border-radius: 999px;
}

.hero__actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin-top: 1.75rem;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.7rem 1.15rem;
    font-size: 0.9375rem;
    font-weight: 600;
    line-height: 1.2;
    border-radius: var(--radius-sm);
    border: 1px solid transparent;
    text-decoration: none;
    transition: background 0.15s ease, border-color 0.15s ease, transform 0.15s ease;
}

.btn:hover {
    text-decoration: none;
    transform: translateY(-1px);
}

.btn--primary {
    color: #fff;
    background: var(--blue);
}

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

.btn--secondary {
    color: var(--blue);
    background: var(--surface);
    border-color: var(--border);
}

.btn--secondary:hover {
    background: var(--blue-soft);
    border-color: #bcd9ff;
}

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

.btn--ghost:hover {
    background: rgba(0, 0, 0, 0.04);
}

.btn--large {
    padding: 0.85rem 1.35rem;
    font-size: 1rem;
}

.hero__screenshot {
    margin: 0;
}

.hero__screenshot img {
    border-radius: var(--radius);
    border: 1px solid var(--border);
    box-shadow: var(--shadow-lg);
}

.hero__screenshot figcaption {
    margin-top: 0.85rem;
    font-size: 0.875rem;
    color: var(--text-muted);
    text-align: center;
}

.stack {
    padding: 0 0 3.5rem;
}

.stack__inner {
    display: grid;
    gap: 2rem;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: calc(var(--radius) + 4px);
    padding: clamp(1.5rem, 4vw, 2.25rem);
    box-shadow: var(--shadow);
}

.stack__intro h2 {
    margin: 0 0 0.75rem;
    font-size: clamp(1.35rem, 3vw, 1.85rem);
    letter-spacing: -0.02em;
}

.stack__intro p {
    margin: 0;
    color: var(--text-muted);
    font-size: 1.0625rem;
    max-width: 58ch;
}

.stack__tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: 1.25rem;
}

.stack__tag {
    display: inline-block;
    padding: 0.4rem 0.75rem;
    font-size: 0.8125rem;
    font-weight: 700;
    font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
    color: var(--blue);
    background: var(--blue-soft);
    border: 1px solid #cfe3ff;
    border-radius: 999px;
}

.stack__list {
    margin: 0;
    padding: 0;
    list-style: none;
    display: grid;
    gap: 0.85rem;
}

.stack__list li {
    position: relative;
    padding-left: 1.6rem;
    color: var(--text);
    font-size: 0.9375rem;
}

.stack__list li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 0.55rem;
    width: 0.55rem;
    height: 0.55rem;
    border-radius: 50%;
    background: var(--blue);
}

.stack__note {
    margin: 1.25rem 0 1rem;
    padding: 0.85rem 1rem;
    font-size: 0.9375rem;
    font-weight: 600;
    color: var(--text);
    background: var(--bg);
    border-left: 3px solid var(--blue);
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.section-header {
    max-width: 42rem;
    margin-bottom: 2rem;
}

.section-header h2,
.highlights h2,
.cta h2 {
    margin: 0 0 0.75rem;
    font-size: clamp(1.5rem, 3vw, 2rem);
    letter-spacing: -0.02em;
}

.section-header p,
.cta p {
    margin: 0;
    color: var(--text-muted);
    font-size: 1.0625rem;
}

.features {
    padding: 1rem 0 3.5rem;
}

.feature-grid {
    display: grid;
    gap: 1rem;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.feature-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.35rem;
    box-shadow: var(--shadow);
}

.feature-card__icon {
    width: 2.5rem;
    height: 2.5rem;
    display: grid;
    place-items: center;
    margin-bottom: 0.85rem;
    color: var(--blue);
    background: var(--blue-soft);
    border-radius: 10px;
}

.feature-card__icon svg {
    width: 1.35rem;
    height: 1.35rem;
}

.feature-card h3 {
    margin: 0 0 0.5rem;
    font-size: 1.0625rem;
}

.feature-card p {
    margin: 0;
    color: var(--text-muted);
    font-size: 0.9375rem;
}

.highlights {
    padding: 0 0 3.5rem;
}

.highlights__inner {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 2rem;
    box-shadow: var(--shadow);
}

.highlights__list {
    margin: 0;
    padding: 0;
    list-style: none;
    display: grid;
    gap: 0.75rem;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
}

.highlights__list li {
    position: relative;
    padding-left: 1.6rem;
    color: var(--text-muted);
}

.highlights__list li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 0.55rem;
    width: 0.55rem;
    height: 0.55rem;
    border-radius: 50%;
    background: var(--blue);
}

.cta {
    padding: 0 0 4rem;
}

.cta__inner {
    text-align: center;
    background: linear-gradient(135deg, #1877f2 0%, #0d5dc7 100%);
    color: #fff;
    border-radius: calc(var(--radius) + 4px);
    padding: clamp(2rem, 5vw, 3rem);
    box-shadow: var(--shadow-lg);
}

.cta__inner h2,
.cta__inner p {
    color: inherit;
}

.cta__inner p {
    max-width: 52ch;
    margin-inline: auto;
    opacity: 0.92;
}

.cta__actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    justify-content: center;
    margin-top: 1.5rem;
}

.cta .btn--primary {
    background: #fff;
    color: var(--blue);
}

.cta .btn--primary:hover {
    background: #f5f8ff;
}

.cta .btn--secondary {
    background: transparent;
    color: #fff;
    border-color: rgba(255, 255, 255, 0.45);
}

.cta .btn--secondary:hover {
    background: rgba(255, 255, 255, 0.1);
}

.site-footer {
    border-top: 1px solid var(--border);
    background: var(--surface);
    padding: 2rem 0;
}

.site-footer__inner {
    display: flex;
    flex-wrap: wrap;
    gap: 1.5rem;
    justify-content: space-between;
    align-items: flex-start;
}

.site-footer p,
.site-footer__links {
    margin: 0;
    color: var(--text-muted);
    font-size: 0.875rem;
}

.site-footer__links {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem 1.25rem;
    align-items: center;
}

@media (min-width: 960px) {
    .hero__grid {
        grid-template-columns: 0.95fr 1.05fr;
    }

    .hero__copy {
        padding-right: 1rem;
    }

    .stack__inner {
        grid-template-columns: 1fr 1fr;
        align-items: start;
    }
}

@media (max-width: 640px) {
    .site-header__inner {
        flex-direction: column;
        align-items: stretch;
        padding-block: 0.75rem;
    }

    .site-nav {
        justify-content: space-between;
    }

    .hero {
        padding-top: 2rem;
    }
}