:root {
    --primary: #2563eb; /* 效率蓝 */
    --primary-hover: #1d4ed8;
    --bg-main: #f8fafc;
    --bg-white: #ffffff;
    --text-dark: #0f172a;
    --text-muted: #64748b;
    --border: #e2e8f0;
    --tab-bg: #f1f5f9;
    --tab-active: #ffffff;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 25px -5px rgba(0,0,0,0.1), 0 8px 10px -6px rgba(0,0,0,0.1);
}

* { margin: 0; padding: 0; box-sizing: border-box; }
body { 
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", sans-serif;
    color: var(--text-dark); background-color: var(--bg-main); line-height: 1.6;
}
a { text-decoration: none; color: inherit; transition: 0.2s; }
ul { list-style: none; }
img { max-width: 100%; display: block; }

.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }

/* 导航 */
header {
    background: var(--bg-white); border-bottom: 1px solid var(--border);
    position: sticky; top: 0; z-index: 100; box-shadow: var(--shadow-sm);
}
.nav-inner { display: flex; justify-content: space-between; align-items: center; height: 70px; }
.logo { font-size: 24px; font-weight: 800; color: var(--primary); display: flex; align-items: center; gap: 8px; }
.logo-icon { width: 24px; height: 24px; background: var(--primary); border-radius: 4px; display: inline-block; position: relative; }
.logo-icon::after { content: ''; position: absolute; top: 4px; left: 4px; width: 8px; height: 8px; background: #fff; border-radius: 2px; }
.nav-links { display: flex; gap: 30px; }
.nav-links a { font-size: 15px; font-weight: 600; color: var(--text-muted); }
.nav-links a:hover, .nav-links a.active { color: var(--primary); }

/* 按钮 */
.btn {
    display: inline-flex; align-items: center; justify-content: center;
    padding: 12px 28px; border-radius: 6px; font-weight: 600; font-size: 16px;
    cursor: pointer; border: none; transition: 0.3s;
}
.btn-primary { background: var(--primary); color: #fff; box-shadow: 0 4px 12px rgba(37,99,235,0.3); }
.btn-primary:hover { background: var(--primary-hover); transform: translateY(-2px); box-shadow: 0 6px 16px rgba(37,99,235,0.4); }
.btn-outline { background: var(--bg-white); color: var(--primary); border: 1px solid var(--primary); }
.btn-outline:hover { background: #eff6ff; }

/* Hero区 */
.hero { padding: 80px 0 100px; text-align: center; background: linear-gradient(180deg, #eff6ff 0%, var(--bg-main) 100%); }
.hero h1 { font-size: 52px; font-weight: 800; margin-bottom: 20px; color: var(--text-dark); letter-spacing: -1px; }
.hero p { font-size: 20px; color: var(--text-muted); margin-bottom: 40px; max-width: 700px; margin-left: auto; margin-right: auto; }
.hero-btns { display: flex; justify-content: center; gap: 20px; margin-bottom: 60px; }

/* 浏览器多标签 UI 模拟 */
.browser-mockup {
    max-width: 1000px; margin: 0 auto; background: var(--bg-white);
    border-radius: 12px; box-shadow: var(--shadow-lg); overflow: hidden;
    border: 1px solid var(--border);
}
.browser-top { background: var(--tab-bg); padding: 10px 10px 0 10px; display: flex; align-items: flex-end; border-bottom: 1px solid var(--border); }
.b-dot-group { display: flex; gap: 6px; padding: 0 15px 12px 5px; }
.b-dot { width: 12px; height: 12px; border-radius: 50%; background: #cbd5e1; }
.b-tabs { display: flex; flex: 1; gap: 5px; overflow: hidden; }
.b-tab {
    background: #e2e8f0; padding: 8px 20px; border-radius: 8px 8px 0 0; font-size: 13px;
    color: var(--text-muted); font-weight: 500; display: flex; align-items: center; gap: 8px;
    max-width: 200px; flex: 1; cursor: default;
}
.b-tab.active { background: var(--tab-active); color: var(--text-dark); position: relative; }
.b-tab.active::before { content: ''; position: absolute; top: 0; left: 0; width: 100%; height: 2px; background: var(--primary); }
.b-tab-close { margin-left: auto; font-size: 14px; opacity: 0.5; }
.browser-address { background: var(--bg-white); padding: 10px 20px; display: flex; border-bottom: 1px solid var(--border); }
.address-bar { flex: 1; background: var(--tab-bg); border-radius: 20px; height: 32px; display: flex; align-items: center; padding: 0 15px; font-size: 13px; color: var(--text-muted); }
.browser-content { position: relative; background: #fff; }
.browser-content img { width: 100%; height: auto; }

/* 模块通用 */
section { padding: 90px 0; border-bottom: 1px solid var(--border); }
.sec-title { text-align: center; font-size: 36px; font-weight: 800; margin-bottom: 60px; color: var(--text-dark); }
.sec-title span { color: var(--primary); }

/* 核心卖点 */
.feature-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 20px; }
.f-card { background: var(--bg-white); padding: 30px 20px; border-radius: 12px; text-align: center; border: 1px solid var(--border); transition: 0.3s; }
.f-card:hover { transform: translateY(-5px); box-shadow: var(--shadow-lg); border-color: #bfdbfe; }
.f-card img { width: 50px; height: 50px; margin: 0 auto 15px; }
.f-card h3 { font-size: 18px; font-weight: 700; margin-bottom: 10px; color: var(--text-dark); }
.f-card p { font-size: 13px; color: var(--text-muted); }

/* 功能详情 (带分屏设计感) */
.detail-item { display: flex; align-items: center; gap: 50px; margin-bottom: 80px; }
.detail-item:nth-child(even) { flex-direction: row-reverse; }
.d-text { flex: 1; }
.d-text h3 { font-size: 28px; font-weight: 800; margin-bottom: 20px; color: var(--text-dark); }
.d-text p { font-size: 16px; color: var(--text-muted); line-height: 1.8; margin-bottom: 20px; }
.d-tag { display: inline-block; background: #eff6ff; color: var(--primary); padding: 6px 12px; border-radius: 4px; font-size: 14px; font-weight: 600; }
.d-img { flex: 1; display: grid; grid-template-columns: 1fr; border-radius: 12px; overflow: hidden; box-shadow: var(--shadow-lg); border: 1px solid var(--border); background: var(--bg-white); padding: 5px; }
.d-img img { border-radius: 8px; border: 1px solid var(--border); }
.split-img { grid-template-columns: 1fr 1fr; gap: 5px; } /* 分屏类 */

/* 对比 */
.compare-box { background: var(--bg-white); border-radius: 16px; border: 1px solid var(--border); overflow: hidden; box-shadow: var(--shadow-sm); }
.compare-table { width: 100%; border-collapse: collapse; text-align: center; }
.compare-table th, .compare-table td { padding: 20px; border-bottom: 1px solid var(--border); }
.compare-table th { background: #f8fafc; font-weight: 700; color: var(--text-dark); }
.compare-table .hl { background: #eff6ff; color: var(--primary); font-weight: 800; }

/* 版本 */
.v-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; }
.v-card { background: var(--bg-white); border: 1px solid var(--border); padding: 40px 30px; border-radius: 12px; text-align: center; transition: 0.3s; position: relative; }
.v-card:hover { border-color: var(--primary); box-shadow: var(--shadow-lg); transform: translateY(-5px); }
.v-card.rec { border-top: 4px solid var(--primary); }
.v-card h3 { font-size: 24px; font-weight: 800; margin-bottom: 15px; color: var(--text-dark); }
.v-card p { font-size: 14px; color: var(--text-muted); margin-bottom: 30px; height: 42px; }

/* 数据展示 */
.data-sec { background: var(--text-dark); color: #fff; padding: 60px 0; border: none; }
.data-flex { display: flex; justify-content: space-around; flex-wrap: wrap; gap: 30px; text-align: center; }
.data-item h4 { font-size: 50px; font-weight: 900; color: #60a5fa; margin-bottom: 5px; }
.data-item p { font-size: 16px; font-weight: 500; }

/* FAQ */
.faq-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; }
.faq-item { background: var(--bg-white); border: 1px solid var(--border); padding: 25px; border-radius: 8px; border-left: 4px solid var(--primary); }
.faq-item h4 { font-size: 16px; font-weight: 700; color: var(--text-dark); margin-bottom: 12px; }
.faq-item p { font-size: 14px; color: var(--text-muted); }

footer { padding: 40px 0; text-align: center; background: #fff; color: var(--text-muted); font-size: 14px; }