/* 全局重置与基础变量 */
:root {
    --primary: #4A90D9;
    --primary-dark: #357ABD;
    --secondary: #6C757D;
    --light-bg: #F8FAFC;
    --white: #FFFFFF;
    --text: #1E293B;
    --text-light: #64748B;
    --border: #E2E8F0;
    --shadow: 0 4px 6px -1px rgba(0,0,0,0.1);
    --radius: 12px;
    --transition: 0.2s ease;
}

* { margin:0; padding:0; box-sizing:border-box; }
body { font-family: system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif; color:var(--text); background:var(--light-bg); line-height:1.6; }
.container { max-width:1200px; margin:0 auto; padding:0 20px; }
.skip-link { position:absolute; left:-999px; top:10px; background:var(--primary); color:#fff; padding:8px 16px; z-index:1000; }
.skip-link:focus { left:10px; }

/* 头部导航 */
.site-header { background:var(--white); box-shadow:0 1px 3px rgba(0,0,0,0.05); position:sticky; top:0; z-index:999; }
.header-container { display:flex; align-items:center; justify-content:space-between; height:70px; }
.logo-link { display:flex; align-items:center; gap:10px; text-decoration:none; color:var(--text); }
.logo-text { font-size:1.5rem; font-weight:700; color:var(--primary-dark); }
.nav-menu { display:flex; list-style:none; gap:25px; align-items:center; }
.nav-link { text-decoration:none; color:var(--text); font-weight:500; padding:8px 0; border-bottom:2px solid transparent; transition:var(--transition); }
.nav-link:hover, .nav-link.active { color:var(--primary); border-bottom-color:var(--primary); }
.nav-download-btn { background:var(--primary); color:#fff !important; padding:8px 20px; border-radius:20px; }
.mobile-menu-toggle { display:none; flex-direction:column; gap:5px; background:none; border:none; cursor:pointer; }
.hamburger-line { width:25px; height:3px; background:var(--text); border-radius:2px; }

/* 英雄区域 */
.hero-section { background:linear-gradient(135deg, #EBF3FB 0%, #D9E9FA 100%); padding:60px 0; }
.hero-container { display:flex; align-items:center; gap:40px; }
.hero-content { flex:1; }
.hero-badge { background:var(--primary); color:#fff; padding:4px 16px; border-radius:20px; font-size:0.9rem; display:inline-block; margin-bottom:15px; }
.hero-title { font-size:2.8rem; margin-bottom:15px; }
.highlight { color:var(--primary); }
.hero-subtitle { font-size:1.1rem; color:var(--text-light); margin-bottom:25px; }
.hero-stats { display:flex; gap:30px; margin-bottom:30px; }
.stat-item { text-align:center; }
.stat-number { font-size:2rem; font-weight:700; color:var(--primary-dark); }
.stat-label { display:block; font-size:0.9rem; color:var(--text-light); }
.hero-actions { display:flex; gap:15px; flex-wrap:wrap; }
.btn { display:inline-flex; align-items:center; gap:8px; padding:14px 32px; border-radius:30px; font-weight:600; text-decoration:none; transition:var(--transition); }
.btn-primary { background:var(--primary); color:#fff; }
.btn-primary:hover { background:var(--primary-dark); transform:translateY(-2px); box-shadow:var(--shadow); }
.btn-secondary { background:var(--white); color:var(--primary); border:2px solid var(--primary); }
.btn-secondary:hover { background:#F0F7FF; }
.hero-version-info { margin-top:20px; font-size:0.9rem; color:var(--text-light); }
.hero-image { flex:1; display:flex; justify-content:center; }
.hero-device-mockup { width:280px; height:400px; background:#fff; border-radius:30px; box-shadow:0 25px 50px -12px rgba(0,0,0,0.25); display:flex; align-items:center; justify-content:center; }
.mockup-screen { width:90%; height:90%; background:var(--light-bg); border-radius:20px; }

/* 通用区块 */
.section-header { text-align:center; margin-bottom:40px; }
.section-header h2 { font-size:2rem; margin-bottom:10px; }
.section-header p { color:var(--text-light); max-width:600px; margin:0 auto; }
.features-grid { display:grid; grid-template-columns:repeat(auto-fit, minmax(300px,1fr)); gap:25px; }
.feature-card { background:var(--white); padding:30px; border-radius:var(--radius); box-shadow:var(--shadow); transition:transform var(--transition); }
.feature-card:hover { transform:translateY(-5px); }
.feature-icon { font-size:2.5rem; margin-bottom:15px; }
.feature-card h3 { margin-bottom:10px; }

.faq-list { max-width:800px; margin:0 auto; }
.faq-item { background:var(--white); border-radius:8px; margin-bottom:10px; padding:15px 20px; box-shadow:0 1px 2px rgba(0,0,0,0.05); }
.faq-item summary { font-weight:600; cursor:pointer; outline:none; }

/* 页脚 */
.site-footer { background:#1E293B; color:#CBD5E1; padding:40px 0 20px; margin-top:60px; }
.footer-grid { display:grid; grid-template-columns:repeat(auto-fit, minmax(200px,1fr)); gap:30px; margin-bottom:20px; }
.footer-col h3 { color:#fff; margin-bottom:15px; }
.footer-col ul { list-style:none; }
.footer-col a { color:#94A3B8; text-decoration:none; }
.footer-bottom { border-top:1px solid #334155; padding-top:20px; text-align:center; font-size:0.9rem; }

/* 功能详情页 */
.page-hero { background:var(--primary); color:#fff; padding:60px 0; text-align:center; }
.features-detailed { padding:60px 0; }
.feature-row { display:flex; align-items:center; gap:40px; margin-bottom:60px; }
.feature-row.reverse { flex-direction:row-reverse; }
.feature-img { flex:1; text-align:center; }
.feature-info { flex:1; }

/* 教程页 */
.tutorial-list { padding:60px 0; max-width:800px; }
.tutorial-step { display:flex; gap:30px; margin-bottom:40px; background:var(--white); padding:30px; border-radius:var(--radius); box-shadow:var(--shadow); }
.step-number { font-size:2.5rem; font-weight:700; color:var(--primary); min-width:70px; }

/* 移动端适配 */
@media (max-width: 768px) {
    .hero-container, .feature-row, .feature-row.reverse { flex-direction:column; }
    .mobile-menu-toggle { display:flex; }
    .nav-menu { display:none; position:absolute; top:70px; left:0; right:0; background:var(--white); flex-direction:column; padding:20px; box-shadow:var(--shadow); }
    .nav-menu.active { display:flex; }
}



/* 手机屏幕内部模拟内容 */
.mockup-screen {
    background: #fff;
    border-radius: 20px;
    padding: 15px;
    display: flex;
    flex-direction: column;
    gap: 18px;
    font-family: system-ui, sans-serif;
    color: #1e293b;
    width: 100%;
    height: 100%;
    box-sizing: border-box;
    overflow: hidden;
}

.screen-status-bar {
    display: flex;
    justify-content: space-between;
    font-size: 0.7rem;
    font-weight: 600;
    padding-bottom: 5px;
    border-bottom: 1px solid #e2e8f0;
}

.screen-device-card {
    background: #f0f7ff;
    border-radius: 14px;
    padding: 15px;
    text-align: center;
}

.screen-device-icon {
    font-size: 2.2rem;
    margin-bottom: 5px;
}

.screen-device-name {
    font-weight: 700;
    font-size: 1rem;
}

.screen-device-status {
    color: #16a34a;
    font-weight: 600;
    font-size: 0.8rem;
}

.screen-storage-info {
    background: #f8fafc;
    border-radius: 12px;
    padding: 12px;
}

.storage-row {
    display: flex;
    justify-content: space-between;
    font-size: 0.7rem;
    margin-bottom: 3px;
}

.storage-bar {
    width: 100%;
    height: 4px;
    background: #e2e8f0;
    border-radius: 2px;
    margin-bottom: 10px;
}

.storage-bar span {
    display: block;
    height: 100%;
    background: #4A90D9;
    border-radius: 2px;
}

.screen-quick-actions {
    display: flex;
    gap: 10px;
    justify-content: center;
}

.action-btn {
    background: #4A90D9;
    color: #fff;
    font-size: 0.7rem;
    font-weight: 600;
    padding: 6px 14px;
    border-radius: 20px;
    text-align: center;
}