/* --- 1. 设计系统 --- */
:root {
    --bg-deep: #050507;
    --bg-card: rgba(30, 30, 32, 0.7);
    --text-primary: #ffffff;
    --text-secondary: #98989d;
    --accent-gradient: linear-gradient(135deg, #2997ff 0%, #bf48ff 100%);
    --glass-border: 1px solid rgba(255, 255, 255, 0.12);
    --font-stack: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Helvetica Neue", sans-serif;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
body {
    font-family: var(--font-stack);
    background-color: var(--bg-deep);
    color: var(--text-primary);
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

/* --- 2. 导航栏 --- */
nav {
    position: fixed; top: 0; width: 100%; height: 60px;
    background: rgba(5, 5, 7, 0.8); backdrop-filter: blur(20px);
    border-bottom: var(--glass-border); z-index: 100;
    display: flex; justify-content: center; align-items: center;
}
.nav-inner {
    width: 90%; max-width: 1200px; display: flex; justify-content: space-between; align-items: center;
}
.logo-box {
    display: flex; align-items: center; gap: 10px; 
    font-weight: 700; font-size: 20px; color: white;
    text-decoration: none;
}
.nav-links a { color: var(--text-secondary); text-decoration: none; font-size: 14px; margin-left: 16px; transition: 0.3s; }
.nav-links a:hover { color: white; }

/* 移动端响应式调整 */
@media (max-width: 768px) {
    /* Hero Section */
    .hero {
        padding-top: 80px;
        padding-bottom: 40px;
    }
    .hero p {
        font-size: clamp(16px, 4vw, 18px);
        max-width: 90%;
    }
    .cta-group {
        flex-direction: column;
        gap: 15px;
        align-items: center;
    }
    .btn {
        width: 80%;
        max-width: 300px;
    }
    .hero-highlights {
        gap: 12px;
    }
    .highlight-pill {
        padding: 8px 16px;
        font-size: 13px;
    }

    /* 导航栏 */
    .nav-links {
        position: fixed;
        bottom: 0;
        left: 0;
        width: 100%;
        background: rgba(10, 10, 12, 0.9);
        backdrop-filter: blur(15px);
        border-top: var(--glass-border);
        display: flex;
        justify-content: space-around;
        align-items: center;
        height: 60px;
        padding: 0 10px;
        z-index: 101;
    }
    .nav-links a {
        margin-left: 0;
        font-size: 13px;
        flex: 1;
        text-align: center;
    }
        body { 
        padding-bottom: 60px; /* 为底部导航栏留出空间 */
    }

    /* 其他区块标题 */
    .section {
        padding: 80px 20px;
    }
    .section-title {
        font-size: 40px; /* 使用clamp确保标题不换行 */
        margin-bottom: 60px;
    }
    .feature-row, .feature-row.reverse {
        flex-direction: column;
        gap: 40px;
        margin-bottom: 80px; /* 减小移动端间距 */
    }
    .feature-visual {
        flex: none; /* 取消flex:1继承，避免尺寸计算问题 */
        width: 100%;
        height: 250px; /* 确保移动端有高度 */
    }
    .feature-text h2 {
        font-size: 32px;
    }

    /* 内容页面 (about, privacy, terms) */
    .content-section {
        padding: 80px 20px 60px;
    }
    .content-section h1 {
        font-size: 32px;
    }
    .content-section h2 {
        font-size: 24px;
    }

    /* 页脚 */
    .footer-grid {
        grid-template-columns: 1fr; /* 单列布局 */
        gap: 30px;
    }
    footer {
        padding: 60px 20px;
    }
}
/* --- 6. 页脚 --- */
footer {
    padding: 80px 24px; 
    border-top: var(--glass-border); 
    font-size: 14px; 
    color: #ccc; 
    background: #020202;
}
.footer-grid { 
    max-width: 1200px; 
    margin: 0 auto; 
    display: grid; 
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); 
    gap: 40px; 
}
.footer-col h4 { color: white; margin-bottom: 20px; }
.footer-col a { display: block; color: #ccc; text-decoration: none; margin-bottom: 10px; }
.footer-col p { margin-bottom: 10px; }

/* --- 通用内容样式 (用于 about, privacy, terms) --- */
.content-section {
    max-width: 800px;
    margin: 0 auto;
    padding: 120px 24px 80px;
}
.content-section h1 {
    font-size: 42px;
    font-weight: 700;
    margin-bottom: 40px;
    border-bottom: 1px solid var(--glass-border);
    padding-bottom: 20px;
}
.content-section h2 {
    font-size: 28px;
    font-weight: 600;
    color: var(--text-primary);
    margin: 40px 0 20px 0;
    padding-top: 8px;
}
.content-section p {
    font-size: 16px;
    line-height: 1.8;
    color: var(--text-secondary);
    margin-bottom: 20px;
}
.content-section ul, .content-section ol {
    padding-left: 24px;
    margin-bottom: 20px;
}
.content-section li {
    margin-bottom: 12px;
    color: var(--text-secondary);
}
.content-section a {
    color: #2997ff;
    text-decoration: none;
}
.content-section a:hover {
    text-decoration: underline;
}

.reveal { opacity: 0; transform: translateY(40px); transition: all 1s cubic-bezier(0.2, 0.8, 0.2, 1); }
.reveal.active { opacity: 1; transform: translateY(0); }