:root {
    --bg-main: #FFFFFF;
    --bg-gray: #F4F7FB;
    --primary-blue: #0066FF;
    --primary-dark: #0047D4;
    --speed-cyan: #00F0FF;
    --speed-orange: #FF6B00;
    --text-dark: #0F172A;
    --text-body: #475569;
    --text-muted: #94A3B8;
    --border-color: #E2E8F0;
    --shadow-speed: 0 10px 30px rgba(0, 102, 255, 0.15);
}

* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: -apple-system, "Segoe UI", Roboto, "Microsoft YaHei", sans-serif; background-color: var(--bg-main); color: var(--text-body); line-height: 1.6; overflow-x: hidden; }
a { text-decoration: none; color: inherit; transition: 0.3s; }
img { max-width: 100%; display: block; }

/* 速度光线背景动画 */
.speed-bg { position: fixed; top: 0; left: 0; width: 100%; height: 100vh; z-index: -1; background: linear-gradient(180deg, #F0F6FF 0%, #FFFFFF 100%); overflow: hidden; pointer-events: none; }
.speed-line { position: absolute; background: linear-gradient(90deg, transparent, rgba(0,102,255,0.2), transparent); height: 2px; width: 200px; animation: speedLine linear infinite; }
.speed-line:nth-child(1) { top: 10%; left: -200px; animation-duration: 3s; animation-delay: 0s; }
.speed-line:nth-child(2) { top: 30%; left: -200px; animation-duration: 4s; animation-delay: 1s; width: 300px; }
.speed-line:nth-child(3) { top: 60%; left: -200px; animation-duration: 2s; animation-delay: 0.5s; width: 150px; }
@keyframes speedLine { 0% { transform: translateX(-100vw); } 100% { transform: translateX(200vw); } }

/* 导航 */
.header { background: rgba(255,255,255,0.9); backdrop-filter: blur(8px); border-bottom: 2px solid var(--primary-blue); position: sticky; top: 0; z-index: 1000; }
.nav-wrap { max-width: 1200px; margin: 0 auto; display: flex; justify-content: space-between; align-items: center; height: 80px; padding: 0 20px; }
.logo { font-size: 26px; font-weight: 900; color: var(--primary-blue); display: flex; align-items: center; gap: 10px; font-style: italic; }
.logo img { width: 38px; height: 38px; }
.nav-links { display: flex; gap: 32px; align-items: center; }
.nav-links a { font-size: 16px; font-weight: 600; color: var(--text-dark); position: relative; }
.nav-links a:hover, .nav-links a.active { color: var(--primary-blue); }
.nav-links a::after { content: ''; position: absolute; bottom: -5px; left: 0; width: 0; height: 3px; background: var(--primary-blue); transition: 0.3s; }
.nav-links a:hover::after, .nav-links a.active::after { width: 100%; }

/* 下载进度条动画按钮 */
.btn-dl { display: inline-flex; align-items: center; justify-content: center; gap: 10px; padding: 18px 40px; border-radius: 50px; font-size: 20px; font-weight: 800; cursor: pointer; transition: 0.3s; position: relative; overflow: hidden; z-index: 1; border: none; }
.btn-dl::before { content: ''; position: absolute; top: 0; left: 0; height: 100%; width: 0%; z-index: -1; transition: 0.4s ease-out; }
.btn-dl:hover::before { width: 100%; }
.btn-primary { background: var(--primary-blue); color: #FFF; box-shadow: var(--shadow-speed); }
.btn-primary::before { background: var(--primary-dark); }
.btn-outline { background: #FFF; color: var(--primary-blue); border: 2px solid var(--primary-blue); }
.btn-outline::before { background: #EFF6FF; }
/* 下载箭头动画 */
.arrow-down { display: inline-block; animation: bounceDown 1.5s infinite; }
@keyframes bounceDown { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(5px); } }

/* 容器与标题 */
.container { max-width: 1200px; margin: 0 auto; padding: 100px 20px; position: relative; z-index: 10; }
.sec-title { text-align: center; font-size: 42px; font-weight: 900; color: var(--text-dark); margin-bottom: 20px; font-style: italic; letter-spacing: -1px; }
.sec-subtitle { text-align: center; font-size: 18px; color: var(--text-muted); margin-bottom: 60px; }

/* Hero区 */
.hero { text-align: center; padding: 80px 20px; overflow: hidden; }
.hero-content { max-width: 800px; margin: 0 auto 50px; }
.dl-status { display: inline-flex; align-items: center; gap: 8px; background: rgba(0, 102, 255, 0.1); color: var(--primary-blue); font-weight: bold; padding: 6px 16px; border-radius: 20px; margin-bottom: 20px; font-size: 14px; border: 1px solid rgba(0, 102, 255, 0.2); }
.dl-status i { display: inline-block; width: 8px; height: 8px; background: var(--speed-cyan); border-radius: 50%; box-shadow: 0 0 8px var(--speed-cyan); }
.hero h1 { font-size: 64px; font-weight: 900; color: var(--text-dark); margin-bottom: 20px; line-height: 1.1; font-style: italic; }
.hero .subtitle { font-size: 24px; color: var(--primary-blue); font-weight: 700; margin-bottom: 40px; }
.hero-btns { display: flex; justify-content: center; gap: 20px; margin-bottom: 50px; }
.hero-visual { max-width: 1000px; margin: 0 auto; position: relative; }
.hero-visual img { border-radius: 12px; box-shadow: 0 30px 60px rgba(0,0,0,0.1); border: 2px solid var(--border-color); border-bottom: 8px solid var(--primary-blue); }

/* 核心卖点 */
.feature-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 20px; }
.f-box { background: #FFF; padding: 40px 20px; border-radius: 16px; text-align: center; box-shadow: var(--shadow-speed); transition: 0.3s; border: 1px solid var(--border-color); position: relative; overflow: hidden; }
.f-box:hover { transform: translateY(-8px); border-color: var(--primary-blue); }
/* 顶部进度条点缀 */
.f-box::before { content: ''; position: absolute; top: 0; left: 0; width: 100%; height: 4px; background: var(--border-color); }
.f-box::after { content: ''; position: absolute; top: 0; left: 0; width: 40%; height: 4px; background: var(--primary-blue); transition: width 0.3s; }
.f-box:hover::after { width: 100%; }
.f-box img { width: 64px; height: 64px; margin: 0 auto 20px; }
.f-box h3 { font-size: 20px; font-weight: 800; color: var(--text-dark); margin-bottom: 10px; font-style: italic; }
.f-box p { font-size: 14px; color: var(--text-body); }

/* 功能详情 - 极速加载风 */
.detail-item { display: flex; align-items: center; gap: 80px; margin-bottom: 100px; }
.detail-item:nth-child(even) { flex-direction: row-reverse; }
.d-text { flex: 1; }
.progress-bar-bg { width: 100%; height: 8px; background: var(--border-color); border-radius: 4px; margin-bottom: 20px; overflow: hidden; }
.progress-bar-fill { height: 100%; background: linear-gradient(90deg, var(--primary-blue), var(--speed-cyan)); width: 85%; animation: load 2s ease-out; }
@keyframes load { 0% { width: 0; } }
.d-text h3 { font-size: 36px; font-weight: 900; color: var(--text-dark); margin-bottom: 20px; font-style: italic; }
.d-text p { font-size: 18px; line-height: 1.8; color: var(--text-body); margin-bottom: 30px; }
.d-data { font-size: 28px; font-weight: 900; color: var(--primary-blue); }
.d-visual { flex: 1.2; position: relative; }
.d-visual img { border-radius: 12px; box-shadow: var(--shadow-speed); }
/* 模拟加载中遮罩 */
.d-visual::after { content: ''; position: absolute; bottom: -10px; right: -10px; width: 80px; height: 80px; background: var(--speed-orange); border-radius: 50%; opacity: 0.1; filter: blur(20px); }

/* 浏览器对比 */
.compare-box { background: #FFF; border-radius: 16px; box-shadow: var(--shadow-speed); overflow: hidden; border: 1px solid var(--border-color); }
.compare-table { width: 100%; border-collapse: collapse; text-align: left; }
.compare-table th, .compare-table td { padding: 25px 30px; border-bottom: 1px solid var(--border-color); }
.compare-table th { background: var(--bg-gray); font-size: 16px; font-weight: 800; color: var(--text-dark); text-transform: uppercase; }
.compare-table td { font-size: 16px; color: var(--text-body); }
.compare-table td.hl { background: rgba(0, 102, 255, 0.05); color: var(--primary-blue); font-weight: 800; border-left: 3px solid var(--primary-blue); }
.compare-table tr:last-child td { border-bottom: none; }

/* 数据背书 */
.data-panel { background: var(--text-dark); color: #FFF; padding: 80px 0; margin: 80px 0; position: relative; overflow: hidden; }
.data-panel::after { content: ''; position: absolute; top: 0; left: 0; width: 200%; height: 100%; background: repeating-linear-gradient(45deg, transparent, transparent 10px, rgba(255,255,255,0.03) 10px, rgba(255,255,255,0.03) 20px); }
.data-inner { max-width: 1200px; margin: 0 auto; display: flex; justify-content: space-around; text-align: center; position: relative; z-index: 2; }
.data-item h4 { font-size: 64px; font-weight: 900; font-style: italic; color: var(--speed-cyan); margin-bottom: 10px; text-shadow: 0 0 20px rgba(0,240,255,0.3); }
.data-item p { font-size: 18px; font-weight: 600; text-transform: uppercase; }

/* 下载选项卡片 */
.dl-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; }
.dl-card { background: #FFF; border: 2px solid var(--border-color); border-radius: 16px; padding: 50px 30px; text-align: center; transition: 0.3s; position: relative; }
.dl-card:hover { border-color: var(--primary-blue); transform: translateY(-10px); box-shadow: var(--shadow-speed); }
.dl-card.pro { border-color: var(--primary-blue); background: #F8FAFC; }
.dl-card.pro::before { content: '官方极速推荐'; position: absolute; top: -14px; left: 50%; transform: translateX(-50%); background: var(--speed-orange); color: #FFF; padding: 6px 20px; border-radius: 20px; font-weight: 800; font-size: 14px; font-style: italic; }
.dl-card h3 { font-size: 28px; font-weight: 900; color: var(--text-dark); margin-bottom: 15px; font-style: italic; }
.dl-card p { font-size: 16px; color: var(--text-body); margin-bottom: 40px; height: 50px; }
.dl-card .btn-dl { width: 100%; font-size: 18px; padding: 15px; }

/* FAQ */
.faq-wrap { max-width: 900px; margin: 0 auto; }
.faq-box { background: #FFF; border: 1px solid var(--border-color); border-radius: 12px; padding: 30px; margin-bottom: 20px; box-shadow: var(--shadow-speed); }
.faq-box h4 { font-size: 18px; font-weight: 800; color: var(--text-dark); margin-bottom: 15px; display: flex; align-items: center; gap: 10px; }
.faq-box h4 i { color: var(--primary-blue); font-style: normal; }
.faq-box p { font-size: 16px; color: var(--text-body); line-height: 1.7; padding-left: 28px; }

/* Footer */
.footer { text-align: center; padding: 60px 20px; background: #FFF; border-top: 1px solid var(--border-color); color: var(--text-muted); font-size: 14px; font-weight: 600; }