/* ===================================================================
   WotOPT — Apple 风格 · 一屏下载页
   设计语言：SF Pro 字体栈 / 深色满屏 Hero / 毛玻璃吸顶导航 /
   蓝链药丸按钮 / 滚动渐显动画 / 极简页脚
   =================================================================== */

:root {
    --bg-white: #ffffff;
    --bg-gray: #f5f5f7;
    --bg-dark: #000000;

    --text-primary: #1d1d1f;
    --text-secondary: #6e6e73;
    --text-invert: #f5f5f7;
    --text-invert-dim: #a1a1a6;

    --accent-blue: #2997ff;
    --btn-blue: #0071e3;
    --btn-blue-hover: #0077ed;

    --border-light: #d2d2d7;

    --nav-height: 48px;
    --max-content: 980px;
    --max-wide: 1200px;

    --font-sf: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text",
               "Helvetica Neue", "PingFang SC", "Hiragino Sans GB",
               "Microsoft YaHei", "Segoe UI", Roboto, sans-serif;
}

* { box-sizing: border-box; }

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

body {
    margin: 0;
    font-family: var(--font-sf);
    color: var(--text-primary);
    background: var(--bg-white);
    line-height: 1.5;
    letter-spacing: -0.01em;
    overflow-x: hidden;
}

/* ===================== 吸顶毛玻璃导航 ===================== */
.nav {
    position: sticky;
    top: 0;
    z-index: 1000;
    height: var(--nav-height);
    background: rgba(255, 255, 255, 0.72);
    backdrop-filter: saturate(180%) blur(20px);
    -webkit-backdrop-filter: saturate(180%) blur(20px);
    border-bottom: 1px solid rgba(0, 0, 0, 0.08);
    transition: background 0.3s ease;
}
.nav-scrolled { background: rgba(255, 255, 255, 0.85); }
.nav-inner {
    max-width: var(--max-wide);
    height: 100%;
    margin: 0 auto;
    padding: 0 22px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}
.nav-brand {
    font-size: 19px;
    font-weight: 600;
    letter-spacing: -0.02em;
    color: var(--text-primary);
    text-decoration: none;
}
.nav-cta {
    font-size: 13px;
    color: #fff;
    background: var(--btn-blue);
    padding: 6px 14px;
    border-radius: 980px;
    text-decoration: none;
    transition: background 0.2s ease;
}
.nav-cta:hover { background: var(--btn-blue-hover); }

/* ===================== 按钮 ===================== */
.btn {
    display: inline-block;
    font-size: 17px;
    font-weight: 400;
    padding: 12px 26px;
    border-radius: 980px;
    text-decoration: none;
    transition: background 0.2s ease, transform 0.2s ease;
    cursor: pointer;
}
.btn-primary { background: var(--btn-blue); color: #fff; }
.btn-primary:hover { background: var(--btn-blue-hover); transform: translateY(-1px); }
.btn-lg { font-size: 19px; padding: 16px 38px; }

/* ===================== 一屏 Hero ===================== */
.hero {
    position: relative;
    background: var(--bg-dark);
    color: var(--text-invert);
    text-align: center;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 100px 22px;
    overflow: hidden;
}
.hero-content {
    position: relative;
    z-index: 2;
    max-width: var(--max-content);
    margin: 0 auto;
}
.hero-eyebrow {
    font-size: 19px;
    font-weight: 600;
    color: var(--accent-blue);
    margin: 0 0 10px;
    letter-spacing: 0.01em;
}
.hero-title {
    font-size: clamp(56px, 11vw, 110px);
    font-weight: 700;
    line-height: 1.02;
    margin: 0 0 14px;
    letter-spacing: -0.03em;
    background: linear-gradient(180deg, #ffffff 30%, #b0b0b8 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}
.hero-subtitle {
    font-size: clamp(22px, 4vw, 38px);
    font-weight: 600;
    line-height: 1.12;
    margin: 0 0 20px;
    letter-spacing: -0.02em;
}
.hero-desc {
    font-size: 18px;
    line-height: 1.6;
    color: var(--text-invert-dim);
    max-width: 600px;
    margin: 0 auto 36px;
}
.hero-actions {
    display: flex;
    align-items: center;
    justify-content: center;
    flex-wrap: wrap;
}
.hero-points {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 12px 32px;
    margin: 52px 0 0;
    padding: 0;
}
.hero-points li {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-size: 15px;
    color: var(--text-invert-dim);
}
.hero-points li span { font-size: 18px; }

/* Hero 光晕 */
.hero-glow {
    position: absolute;
    top: -10%;
    left: 50%;
    transform: translateX(-50%);
    width: 900px;
    height: 600px;
    background: radial-gradient(circle, rgba(41,151,255,0.28), transparent 60%);
    filter: blur(40px);
    z-index: 1;
    pointer-events: none;
}

/* ===================== 极简页脚 ===================== */
.site-footer {
    background: var(--bg-gray);
    border-top: 1px solid var(--border-light);
    padding: 22px 22px;
    font-size: 12px;
    color: var(--text-secondary);
}
.footer-inner { max-width: var(--max-wide); margin: 0 auto; text-align: center; }
.footer-links {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 24px;
    margin-bottom: 10px;
}
.footer-links a, .footer-qq {
    color: var(--text-secondary);
    text-decoration: none;
    transition: color 0.2s ease;
}
.footer-links a:hover { color: var(--text-primary); }
.footer-fine { color: #86868b; margin: 0; }

/* ===================== 滚动渐显 ===================== */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s cubic-bezier(0.22, 1, 0.36, 1),
                transform 0.8s cubic-bezier(0.22, 1, 0.36, 1);
    will-change: opacity, transform;
}
.reveal.is-visible { opacity: 1; transform: translateY(0); }

/* ===================== 响应式 ===================== */
@media (max-width: 640px) {
    .hero { padding: 90px 18px; }
    .hero-actions { flex-direction: column; gap: 18px; }
    .hero-points { gap: 10px 18px; margin-top: 40px; }
}