/* Self-hosted Google Sans (OFL, open-sourced by Google). Zero external CDN
   dependency so the site renders in China without hitting the GFW-blocked
   fonts.gstatic.com. Chinese glyphs fall through to system fonts below. */
@font-face {
    font-family: "Google Sans";
    font-style: normal;
    font-weight: 400;
    font-display: swap;
    src: url("fonts/google-sans-latin-400-normal.woff2") format("woff2");
}
@font-face {
    font-family: "Google Sans";
    font-style: normal;
    font-weight: 500;
    font-display: swap;
    src: url("fonts/google-sans-latin-500-normal.woff2") format("woff2");
}
@font-face {
    font-family: "Google Sans";
    font-style: normal;
    font-weight: 600;
    font-display: swap;
    src: url("fonts/google-sans-latin-600-normal.woff2") format("woff2");
}
@font-face {
    font-family: "Google Sans";
    font-style: normal;
    font-weight: 700;
    font-display: swap;
    src: url("fonts/google-sans-latin-700-normal.woff2") format("woff2");
}

:root {
    --bg: #08080a;
    --bg-2: #0d0d10;
    --bg-3: #121216;
    --panel: #131318;
    --panel-border: rgba(255, 255, 255, 0.08);
    --panel-hover: rgba(255, 255, 255, 0.12);
    --text: #ededf0;
    --text-2: #8a8a93;
    --text-3: #5c5c66;
    --accent: #3b82f6;
    --accent-hover: #2f6fe0;
    --radius: 14px;
    --radius-sm: 9px;
    --font: "Google Sans", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei",
            "Segoe UI", "Helvetica Neue", Arial, sans-serif;
    --mono: Consolas, "SF Mono", Menlo, ui-monospace, "Liberation Mono", "Courier New", monospace;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font);
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    overflow-x: hidden;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
}

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

.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    padding: 16px 0;
    border-bottom: 1px solid transparent;
    transition: background 0.25s ease, border-color 0.25s ease, backdrop-filter 0.25s ease;
}

.nav.scrolled {
    background: rgba(8, 8, 10, 0.8);
    backdrop-filter: blur(14px);
    border-bottom-color: var(--panel-border);
}

.nav-inner {
    max-width: 1120px;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 600;
    font-size: 1.05rem;
    letter-spacing: 0.02em;
}

.logo-mark {
    width: 30px;
    height: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 7px;
    background: var(--accent);
    color: #fff;
    font-family: var(--mono);
    font-weight: 600;
    font-size: 0.95rem;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 32px;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-2);
}

.nav-links a {
    transition: color 0.18s ease;
}

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

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 11px 22px;
    border-radius: var(--radius-sm);
    font-weight: 500;
    font-size: 0.9rem;
    transition: background 0.18s ease, border-color 0.18s ease, color 0.18s ease;
    border: 1px solid transparent;
    cursor: pointer;
}

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

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

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

.btn-secondary:hover {
    border-color: var(--panel-hover);
    background: rgba(255, 255, 255, 0.04);
}

.btn-ghost {
    padding: 7px 16px;
    border-color: var(--panel-border);
    color: var(--text-2);
    background: transparent;
    font-weight: 500;
}

.btn-ghost:hover {
    color: var(--text);
    border-color: var(--panel-hover);
}

.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 140px 24px 100px;
    gap: 64px;
    max-width: 1200px;
    margin: 0 auto;
}

.hero-content {
    flex: 1;
    max-width: 600px;
}

.eyebrow {
    display: inline-block;
    font-family: var(--mono);
    font-size: 0.74rem;
    font-weight: 500;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--accent);
    margin-bottom: 18px;
}

.hero-title {
    font-size: clamp(3rem, 7vw, 5rem);
    font-weight: 700;
    letter-spacing: -0.04em;
    line-height: 1;
    margin-bottom: 26px;
}

.hero-desc {
    font-size: 1.08rem;
    color: var(--text-2);
    max-width: 520px;
    margin-bottom: 34px;
    line-height: 1.75;
}

.hero-actions {
    display: flex;
    gap: 14px;
    margin-bottom: 52px;
    flex-wrap: wrap;
}

.hero-stats {
    display: flex;
    gap: 44px;
}

.stat {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.stat-value {
    font-family: var(--mono);
    font-size: 1.9rem;
    font-weight: 600;
    color: var(--text);
}

.stat-label {
    font-size: 0.8rem;
    color: var(--text-3);
    font-weight: 500;
}

.hero-terminal {
    width: 100%;
    max-width: 500px;
    background: var(--panel);
    border: 1px solid var(--panel-border);
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: 0 18px 60px rgba(0, 0, 0, 0.4);
}

.terminal-header {
    display: flex;
    align-items: center;
    gap: 7px;
    padding: 13px 16px;
    background: rgba(0, 0, 0, 0.25);
    border-bottom: 1px solid var(--panel-border);
}

.terminal-dot {
    width: 11px;
    height: 11px;
    border-radius: 50%;
}

.terminal-dot.red { background: #b8b8c0; }
.terminal-dot.yellow { background: #b8b8c0; }
.terminal-dot.green { background: #b8b8c0; }

.terminal-title {
    margin-left: 8px;
    font-size: 0.76rem;
    color: var(--text-2);
    font-family: var(--mono);
}

.terminal-body,
.download-code pre {
    padding: 20px;
    font-family: var(--mono);
    font-size: 0.82rem;
    line-height: 1.7;
    color: var(--text);
    background: transparent;
    white-space: pre-wrap;
    overflow: auto;
}

.terminal-body .cmd {
    color: var(--accent);
}

.terminal-body .ans {
    color: var(--text-2);
}

section {
    padding: 110px 24px;
}

.section-inner {
    max-width: 1120px;
    margin: 0 auto;
}

.section-header {
    margin-bottom: 64px;
    max-width: 600px;
}

.section-header.centered {
    margin-left: auto;
    margin-right: auto;
    text-align: center;
}

.section-title {
    font-size: clamp(1.8rem, 3.6vw, 2.6rem);
    font-weight: 600;
    letter-spacing: -0.02em;
    line-height: 1.2;
}

.features {
    background: var(--bg-2);
    border-top: 1px solid var(--panel-border);
    border-bottom: 1px solid var(--panel-border);
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 18px;
}

.feature-card {
    background: var(--panel);
    border: 1px solid var(--panel-border);
    border-radius: var(--radius);
    padding: 28px;
    transition: border-color 0.2s ease, transform 0.2s ease;
}

.feature-card:hover {
    border-color: var(--panel-hover);
    transform: translateY(-3px);
}

.feature-icon {
    color: var(--accent);
    margin-bottom: 18px;
}

.feature-icon svg {
    width: 26px;
    height: 26px;
}

.feature-card h3 {
    font-size: 1.12rem;
    font-weight: 600;
    margin-bottom: 10px;
}

.feature-card p {
    color: var(--text-2);
    line-height: 1.7;
    font-size: 0.94rem;
}

.architecture {
    background: var(--bg);
}

.arch-diagram {
    display: flex;
    flex-direction: column;
    max-width: 680px;
    margin: 0 auto;
}

.arch-layer {
    background: var(--panel);
    border: 1px solid var(--panel-border);
    border-radius: var(--radius);
    padding: 24px 28px;
    text-align: center;
    transition: border-color 0.2s ease;
}

.arch-layer:hover {
    border-color: var(--panel-hover);
}

.arch-title {
    font-weight: 600;
    font-size: 1.02rem;
    margin-bottom: 6px;
}

.arch-desc {
    color: var(--text-2);
    font-size: 0.9rem;
}

.arch-connector {
    width: 1px;
    height: 30px;
    background: var(--panel-border);
    margin: 0 auto;
}

.roadmap {
    background: var(--bg-3);
    border-top: 1px solid var(--panel-border);
    border-bottom: 1px solid var(--panel-border);
}

.timeline {
    position: relative;
    max-width: 680px;
    margin: 0 auto;
    padding-left: 22px;
    border-left: 1px solid var(--panel-border);
}

.timeline-item {
    position: relative;
    padding: 0 0 42px 36px;
    opacity: 0.55;
    transition: opacity 0.3s ease;
}

.timeline-item:last-child {
    padding-bottom: 0;
}

.timeline-item.done,
.timeline-item.active {
    opacity: 1;
}

.timeline-dot {
    position: absolute;
    left: -33px;
    top: 3px;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--bg-3);
    border: 2px solid var(--text-3);
    transition: border-color 0.3s ease;
}

.timeline-item.done .timeline-dot {
    background: var(--accent);
    border-color: var(--accent);
}

.timeline-item.active .timeline-dot {
    background: var(--bg-3);
    border-color: var(--accent);
}

.timeline-phase {
    font-family: var(--mono);
    font-size: 0.7rem;
    color: var(--accent);
    letter-spacing: 0.08em;
    text-transform: uppercase;
    margin-bottom: 5px;
}

.timeline-content h3 {
    font-size: 1.12rem;
    margin-bottom: 7px;
}

.timeline-content p {
    color: var(--text-2);
    font-size: 0.92rem;
    line-height: 1.65;
}

.download {
    padding-bottom: 150px;
}

.download-card {
    display: flex;
    gap: 44px;
    align-items: center;
    background: var(--panel);
    border: 1px solid var(--panel-border);
    border-radius: var(--radius);
    padding: 52px;
}

.download-text {
    flex: 1;
}

.download-text p {
    color: var(--text-2);
    margin-bottom: 26px;
    max-width: 500px;
}

.download-actions {
    display: flex;
    gap: 14px;
    margin-bottom: 26px;
    flex-wrap: wrap;
}

.download-meta {
    font-family: var(--mono);
    font-size: 0.76rem;
    color: var(--text-3);
    display: flex;
    gap: 10px;
    align-items: center;
}

.download-meta .sep {
    opacity: 0.4;
}

.download-code {
    flex: 0 0 400px;
    background: var(--bg);
    border: 1px solid var(--panel-border);
    border-radius: var(--radius-sm);
    overflow: hidden;
}

.download-code pre {
    margin: 0;
}

.download-code code {
    font-family: var(--mono);
    color: var(--text);
}

.footer {
    border-top: 1px solid var(--panel-border);
    padding: 56px 24px;
    text-align: center;
}

.footer-inner {
    max-width: 1120px;
    margin: 0 auto;
}

.footer-brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-size: 1.02rem;
    font-weight: 600;
    margin-bottom: 14px;
}

.footer-copy {
    color: var(--text-2);
    font-size: 0.86rem;
    line-height: 1.8;
}

.footer-copy a {
    color: var(--accent);
}

@media (max-width: 900px) {
    .hero {
        flex-direction: column;
        padding-top: 130px;
        gap: 48px;
    }

    .hero-terminal {
        max-width: 100%;
    }

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

    .download-code {
        flex: 1 1 auto;
        width: 100%;
    }

    .nav-links {
        display: none;
    }
}

@media (max-width: 560px) {
    .hero-actions,
    .download-actions {
        flex-direction: column;
        width: 100%;
    }

    .btn {
        width: 100%;
    }

    .hero-stats {
        gap: 22px;
    }

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

    .download-card {
        padding: 26px;
    }

    section {
        padding: 80px 24px;
    }
}