/* ============================
   粒刻 - Xiaomi MiMo 风格
   ============================ */

:root {
    --bg: #fcfaf8;
    --bg-card: #f3ede8;
    --border: #f0ebe5;
    --text-primary: #000;
    --text-secondary: #666;
    --text-muted: #999;
    --font-main: "PingFang SC", -apple-system, "Noto Sans SC", sans-serif;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-main);
    background: var(--bg);
    color: var(--text-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ---- Navigation ---- */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: rgba(252, 250, 248, 0.9);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid transparent;
    transition: all 0.3s ease;
}

.nav-inner {
    max-width: 1260px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 54px;
    padding: 0 28px;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 8px;
    text-decoration: none;
    color: var(--text-primary);
}

.nav-logo-icon {
    width: 28px;
    height: 28px;
    background: var(--text-primary);
    color: var(--bg);
    border-radius: 6px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 14px;
}

.nav-logo-text {
    font-size: 16px;
    font-weight: 700;
    letter-spacing: 0.02em;
}

.nav-links {
    display: flex;
    gap: 36px;
}

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 14px;
    font-weight: 400;
    transition: color 0.2s;
}

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

.nav-btn {
    display: inline-flex;
    align-items: center;
    padding: 8px 20px;
    background: var(--text-primary);
    color: var(--bg);
    border-radius: 20px;
    font-size: 13px;
    font-weight: 500;
    text-decoration: none;
    transition: opacity 0.2s;
}

.nav-btn:hover {
    opacity: 0.85;
}

/* ---- Hero ---- */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 120px 28px 80px;
    position: relative;
    overflow: hidden;
}

.hero-inner {
    max-width: 1260px;
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 60px;
    position: relative;
    z-index: 1;
}

.hero-content {
    flex: 1;
}

.hero-title {
    font-size: 120px;
    font-weight: 900;
    line-height: 1;
    letter-spacing: -0.03em;
    margin-bottom: 24px;
}

.hero-subtitle {
    font-size: 28px;
    font-weight: 300;
    color: var(--text-secondary);
    line-height: 1.4;
}

.hero-visual {
    flex-shrink: 0;
    width: 500px;
    height: 500px;
    position: relative;
}

#particleCanvas {
    width: 100%;
    height: 100%;
    position: absolute;
    top: 0;
    left: 0;
}

/* ---- Sections ---- */
.section {
    padding: 72px 28px;
}

.section-inner {
    max-width: 1260px;
    margin: 0 auto;
}

.section-header {
    margin-bottom: 48px;
}

.section-title {
    font-size: 36px;
    font-weight: 700;
    margin-bottom: 12px;
}

.section-desc {
    font-size: 16px;
    color: var(--text-secondary);
}

/* ---- Features Grid ---- */
.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
}

.feature-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 32px;
    transition: all 0.3s ease;
    cursor: default;
}

.feature-card:hover {
    background: var(--text-primary);
    color: var(--bg);
    border-color: var(--text-primary);
}

.feature-card:hover .feature-num {
    color: var(--text-muted);
}

.feature-card:hover h3 {
    color: var(--bg);
}

.feature-card:hover p {
    color: var(--text-muted);
}

.feature-num {
    font-size: 12px;
    font-weight: 500;
    color: var(--text-muted);
    margin-bottom: 16px;
    letter-spacing: 0.05em;
}

.feature-card h3 {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 10px;
}

.feature-card p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ---- Download ---- */
.section-download {
    background: var(--bg-card);
    border-top: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
}

.download-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
}

.download-card {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 32px 24px;
    text-align: center;
    transition: all 0.3s ease;
}

.download-card:hover {
    border-color: var(--text-primary);
}

.download-icon {
    font-size: 32px;
    margin-bottom: 16px;
    opacity: 0.6;
}

.download-card h3 {
    font-size: 16px;
    font-weight: 700;
    margin-bottom: 4px;
}

.download-card p {
    font-size: 13px;
    color: var(--text-muted);
    margin-bottom: 20px;
}

.download-btn {
    display: inline-block;
    padding: 8px 20px;
    background: var(--text-primary);
    color: var(--bg);
    border-radius: 20px;
    font-size: 13px;
    font-weight: 500;
    text-decoration: none;
    transition: opacity 0.2s;
}

.download-btn:hover {
    opacity: 0.85;
}

.download-btn-coming {
    background: transparent;
    color: var(--text-muted);
    border: 1px solid var(--border);
}

/* ---- About ---- */
.about-content {
    max-width: 640px;
}

.about-content p {
    font-size: 16px;
    color: var(--text-secondary);
    line-height: 1.9;
    margin-bottom: 16px;
}

/* ---- Privacy Link ---- */
.section-privacy {
    padding: 40px 28px;
}

.privacy-link a {
    color: var(--text-muted);
    text-decoration: none;
    font-size: 14px;
    transition: color 0.2s;
}

.privacy-link a:hover {
    color: var(--text-primary);
}

/* ---- Footer ---- */
.footer {
    border-top: 1px solid var(--border);
    padding: 24px 28px;
}

.footer-inner {
    max-width: 1260px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer-left {
    display: flex;
    align-items: center;
    gap: 16px;
}

.footer-logo {
    font-weight: 700;
    font-size: 14px;
}

.footer-copy {
    color: var(--text-muted);
    font-size: 13px;
}

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

.footer-links a {
    color: var(--text-muted);
    text-decoration: none;
    font-size: 13px;
    transition: color 0.2s;
}

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

/* ---- Responsive ---- */
@media (max-width: 1024px) {
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }

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

    .hero-title {
        font-size: 80px;
    }

    .hero-visual {
        width: 360px;
        height: 360px;
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
    }

    .nav-inner {
        padding: 0 20px;
    }

    .hero {
        padding: 100px 20px 60px;
        min-height: auto;
    }

    .hero-inner {
        flex-direction: column;
        text-align: center;
    }

    .hero-title {
        font-size: 64px;
    }

    .hero-subtitle {
        font-size: 20px;
    }

    .hero-visual {
        width: 300px;
        height: 300px;
    }

    .section {
        padding: 48px 20px;
    }

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

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

    .section-title {
        font-size: 28px;
    }

    .footer-inner {
        flex-direction: column;
        gap: 16px;
        text-align: center;
    }
}