@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&display=swap');

:root {
    --vercel-black: #000;
    --vercel-white: #fff;
    --gray-50: #fafafa;
    --gray-100: #f5f5f5;
    --gray-200: #eaeaea;
    --gray-300: #999;
    --gray-400: #888;
    --gray-500: #666;
    --gray-600: #444;
    --gray-700: #333;
    --gray-800: #222;
    --gray-900: #111;
    --success: #0070f3;
    --error: #ee0000;
    --warning: #f5a623;
    --radius: 8px;
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Microsoft YaHei", "PingFang SC", sans-serif;
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.05);
    --shadow-lg: 0 12px 30px rgba(0,0,0,0.08);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    background: var(--vercel-white);
    color: var(--vercel-black);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

a {
    color: inherit;
    text-decoration: none;
}

.shell {
    width: min(1120px, calc(100vw - 32px));
    margin: 0 auto;
}

/* ===== Topbar ===== */
.topbar {
    position: sticky;
    top: 0;
    z-index: 20;
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    background: rgba(255, 255, 255, 0.85);
    border-bottom: 1px solid var(--gray-200);
}

.topbar-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    padding: 14px 0;
}

.brand {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
    font-size: 1.1rem;
    color: var(--vercel-black);
}

.brand-mark {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    color: var(--vercel-white);
    background: var(--vercel-black);
    border-radius: var(--radius);
}

.nav {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    align-items: center;
}

.nav a {
    padding: 8px 14px;
    border-radius: var(--radius);
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--gray-600);
    transition: all 0.15s ease;
}

.nav a:hover {
    background: var(--gray-100);
    color: var(--vercel-black);
}

.lang-switch {
    display: flex;
    gap: 4px;
    margin-left: 8px;
    padding-left: 12px;
    border-left: 1px solid var(--gray-200);
}

.lang-switch button {
    background: transparent;
    color: var(--gray-500);
    border: none;
    padding: 6px 10px;
    border-radius: var(--radius);
    font: inherit;
    font-size: 0.8rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.15s ease;
}

.lang-switch button:hover {
    color: var(--vercel-black);
    background: var(--gray-100);
}

.lang-switch button.active {
    background: var(--vercel-black);
    color: var(--vercel-white);
}

/* ===== Hero ===== */
.hero {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    padding: 80px 24px 60px;
    gap: 32px;
    max-width: 900px;
    margin: 0 auto;
}

.hero-copy {
    display: flex;
    flex-direction: column;
    align-items: center;
    background: transparent;
    border: none;
    box-shadow: none;
    padding: 0;
}

.eyebrow {
    display: inline-flex;
    padding: 6px 14px;
    border-radius: 999px;
    background: var(--gray-100);
    color: var(--gray-600);
    font-weight: 500;
    font-size: 0.85rem;
    letter-spacing: 0.02em;
    border: 1px solid var(--gray-200);
}

h1, h2, h3, h4 {
    margin: 0;
    line-height: 1.2;
    letter-spacing: -0.02em;
}

h1 {
    margin-top: 20px;
    font-size: clamp(2.5rem, 5vw, 4.5rem);
    font-weight: 800;
    letter-spacing: -0.03em;
    line-height: 1.1;
}

.lead {
    margin: 16px 0 0;
    font-size: 1.1rem;
    line-height: 1.7;
    color: var(--gray-500);
    max-width: 720px;
}

.cta-row {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 12px;
    margin-top: 32px;
}

.button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 44px;
    padding: 0 24px;
    border-radius: var(--radius);
    font-weight: 500;
    font-size: 0.9rem;
    transition: all 0.15s ease;
    cursor: pointer;
    border: none;
    font-family: var(--font-sans);
}

.button.primary {
    background: var(--vercel-black);
    color: var(--vercel-white);
}

.button.primary:hover {
    opacity: 0.8;
}

.button.secondary {
    background: var(--gray-100);
    color: var(--vercel-black);
    border: 1px solid var(--gray-200);
}

.button.secondary:hover {
    background: var(--gray-200);
    border-color: var(--gray-300);
}

/* ===== Stats Banner ===== */
.stats-banner {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
    padding: 40px 0;
    margin-bottom: 64px;
}

.stat {
    padding: 24px;
    border: 1px solid var(--gray-200);
    border-radius: var(--radius);
    text-align: center;
    transition: box-shadow 0.2s;
}

.stat:hover {
    box-shadow: var(--shadow-md);
}

.stat strong {
    display: block;
    font-size: 1rem;
    font-weight: 700;
    color: var(--vercel-black);
    margin-bottom: 6px;
}

.stat span {
    font-size: 0.85rem;
    color: var(--gray-500);
    line-height: 1.5;
}

/* ===== Panels / Cards ===== */
.panel {
    background: var(--vercel-white);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius);
    padding: 28px;
    transition: box-shadow 0.2s;
}

.panel:hover {
    box-shadow: var(--shadow-md);
}

.section {
    padding: 28px;
}

.section h2 {
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    margin-bottom: 4px;
}

.section-stack {
    display: flex;
    flex-direction: column;
    gap: 48px;
    padding-bottom: 80px;
}

/* ===== Feature / Support / Contact Grids ===== */
.feature-grid,
.support-grid,
.contact-grid {
    display: grid;
    gap: 20px;
    margin-top: 20px;
}

.feature-grid {
    grid-template-columns: repeat(3, 1fr);
}

.support-grid {
    grid-template-columns: repeat(2, 1fr);
}

.contact-grid {
    grid-template-columns: repeat(3, 1fr);
}

.legal-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
    margin-top: 20px;
}

.feature-card,
.support-card,
.download-card {
    padding: 24px;
    border: 1px solid var(--gray-200);
    border-radius: var(--radius);
    transition: all 0.2s;
}

.feature-card:hover,
.support-card:hover {
    box-shadow: var(--shadow-md);
}

.feature-card h3,
.support-card h3 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 8px;
}

.feature-card p,
.support-card p,
.download-card p {
    color: var(--gray-500);
    line-height: 1.6;
    font-size: 0.9rem;
}

/* ===== Download List ===== */
.download-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-top: 20px;
}

.download-card {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 18px;
}

.download-card h3 {
    font-size: 0.95rem;
    font-weight: 600;
    margin-bottom: 4px;
}

.download-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    font-size: 0.82rem;
    color: var(--gray-400);
}

/* ===== Legal Pages ===== */
.legal-card {
    padding: 40px;
}

.legal-card h1 {
    margin-bottom: 24px;
}

.legal-card p,
.legal-card li {
    color: var(--gray-500);
    line-height: 1.7;
    font-size: 0.95rem;
}

.legal-card ul {
    margin: 12px 0 0;
    padding-left: 20px;
}

/* ===== Footer ===== */
.footer {
    padding: 24px 0 40px;
    color: var(--gray-500);
    font-size: 0.85rem;
}

.footer-bar {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    padding-top: 20px;
    border-top: 1px solid var(--gray-200);
}

.footer-links {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
}

.footer-links a {
    color: var(--gray-600);
    font-weight: 500;
    transition: color 0.15s;
}

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

/* ===== Language Visibility ===== */
[data-lang] {
    display: none;
}

body.lang-en [data-lang="en"],
body.lang-zh [data-lang="zh"],
body.lang-ms [data-lang="ms"] {
    display: block;
}

body.lang-en [data-lang-inline="en"],
body.lang-zh [data-lang-inline="zh"],
body.lang-ms [data-lang-inline="ms"] {
    display: inline;
}

[data-lang-inline] {
    display: none;
}

/* ===== Responsive ===== */
@media (max-width: 900px) {
    .hero {
        padding: 48px 16px 40px;
    }

    .stats-banner {
        grid-template-columns: repeat(2, 1fr);
        gap: 16px;
        padding: 24px 0;
        margin-bottom: 40px;
    }

    .feature-grid,
    .support-grid,
    .contact-grid,
    .legal-grid {
        grid-template-columns: 1fr;
    }

    .download-card {
        flex-direction: column;
        align-items: flex-start;
    }

    .topbar-inner {
        flex-direction: column;
        align-items: flex-start;
    }

    .nav {
        justify-content: flex-start;
        width: 100%;
    }

    .lang-switch {
        margin-left: 0;
        padding-left: 0;
        border-left: none;
    }

    .legal-card {
        padding: 24px;
    }
}

@media (max-width: 480px) {
    .stats-banner {
        grid-template-columns: 1fr;
    }
}