/* --- 1. Design System --- */
:root {
    --primary: #0f172a;       
    --accent: #2563eb;        
    --accent-hover: #1d4ed8;
    --text-main: #1e293b;
    --text-muted: #64748b;
    --text-light: #94a3b8;
    --bg-white: #ffffff;
    --bg-light: #f8fafc;
    --max-width: 1200px;
    --radius: 8px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    color: var(--text-main);
    line-height: 1.6;
    background-color: var(--bg-white);
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

a { text-decoration: none; transition: 0.2s; }
img { display: block; width: 100%; height: auto; }
ul { list-style: none; }

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
}

.section { padding: 100px 0; }
#contact { padding-bottom: 60px; } /* 稍微增加一点底部距离，避免太挤 */
.bg-light { background-color: var(--bg-light); }

/* --- 2. Navigation --- */
header {
    position: fixed;
    top: 0; width: 100%; height: 80px; z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid #e2e8f0;
}
.nav-inner {
    height: 100%;
    display: grid;
    grid-template-columns: 240px 1fr auto; /* 右侧自适应 */
    align-items: center;
    gap: 20px;
}
.logo-wrapper { display: flex; flex-direction: column; justify-content: center; }
.logo { font-size: 1.1rem; font-weight: 800; color: var(--primary); line-height: 1.1; letter-spacing: -0.02em; }
.logo-tag { font-size: 0.65rem; text-transform: uppercase; letter-spacing: 2px; color: var(--text-muted); font-weight: 600; margin-top: 3px; }

.nav-menu { display: flex; justify-content: center; gap: 40px; }
.nav-menu a { font-size: 0.95rem; font-weight: 500; color: var(--text-main); position: relative; cursor: pointer; white-space: nowrap; }
.nav-menu a:hover { color: var(--accent); }
.nav-menu a::after { content: ''; position: absolute; bottom: -4px; left: 0; width: 0; height: 2px; background: var(--accent); transition: width 0.3s; }
.nav-menu a:hover::after { width: 100%; }

/* --- 右侧按钮组样式修复 --- */
.nav-actions { 
    display: flex; 
    justify-content: flex-end; 
    align-items: center; 
    gap: 12px; /* 按钮之间的间距 */
}

/* 修复开发者按钮：强制不换行，统一高度 */
.btn-nav { 
    background: var(--primary); 
    color: white; 
    padding: 0 20px; /* 左右内边距 */
    height: 40px;    /* 固定高度 */
    line-height: 40px; /* 文字垂直居中 */
    border-radius: 6px; 
    font-size: 0.9rem; 
    font-weight: 600; 
    border: 1px solid var(--primary); 
    white-space: nowrap; /* 核心修复：禁止文字换行 */
    display: inline-flex;
    align-items: center;
    justify-content: center;
}
.btn-nav:hover { background: white; color: var(--primary); }

/* --- Language Dropdown (精致小巧版) --- */
.lang-dropdown { 
    position: relative; 
    display: inline-flex; 
    align-items: center;  
    /* 容器高度跟随内容，靠 flex 居中 */
    z-index: 1100;
}

/* 当前语言显示按钮 */
.current-lang {
    background: transparent;
    border: 1px solid #e2e8f0;
    /* 调整：减小内边距 */
    padding: 0 10px;
    /* 调整：高度减小到 34px (比右边的 40px 按钮小一圈) */
    height: 34px;    
    border-radius: 6px;
    cursor: pointer;
    /* 调整：字体变小 */
    font-size: 0.85rem; 
    font-weight: 600;
    color: var(--text-main);
    display: flex; 
    align-items: center; 
    justify-content: center;
    gap: 6px;
    transition: all 0.2s;
    white-space: nowrap; 
    /* 调整：最小宽度减小 */
    min-width: 100px;
    background-color: #fff;
    margin: 0; 
}
.current-lang:hover { border-color: var(--accent); color: var(--accent); background-color: #f8fafc; }

.arrow-icon { opacity: 0.6; transition: transform 0.2s; flex-shrink: 0; width: 10px; height: 10px; /* 图标也稍微缩小 */ }

/* 下拉菜单容器 */
.lang-menu {
    display: block; 
    opacity: 0;
    visibility: hidden;
    position: absolute; 
    top: 100%; 
    right: 0; 
    margin-top: 8px; /* 间距微调 */
    background: #ffffff; 
    /* 调整：菜单宽度跟随按钮 */
    min-width: 100px;
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    border-radius: 8px; 
    border: 1px solid #e2e8f0; 
    transition: all 0.2s ease-in-out; 
    transform: translateY(-10px); 
}

/* --- 隐形桥梁 (保持交互顺滑) --- */
.lang-menu::before {
    content: "";
    position: absolute;
    top: -15px; 
    left: 0;
    width: 100%;
    height: 15px; 
    background: transparent; 
}

.lang-option { 
    /* 调整：选项内边距减小 */
    padding: 10px 14px; 
    /* 调整：字体变小 */
    font-size: 0.85rem; 
    color: var(--text-main); 
    cursor: pointer; 
    transition: background 0.2s; 
    font-weight: 500; 
    text-align: left; 
    white-space: nowrap; 
}

/* 圆角处理 */
.lang-option:first-child { border-top-left-radius: 8px; border-top-right-radius: 8px; }
.lang-option:last-child { border-bottom-left-radius: 8px; border-bottom-right-radius: 8px; }

.lang-option:hover { background-color: #f1f5f9; color: var(--accent); }

/* 鼠标悬停逻辑 */
.lang-dropdown:hover .lang-menu { 
    opacity: 1;
    visibility: visible;
    transform: translateY(0); 
}
.lang-dropdown:hover .arrow-icon { transform: rotate(180deg); }


/* --- 3. Hero --- */
.hero { position: relative; padding-top: 180px; padding-bottom: 120px; background: linear-gradient(180deg, #f0f9ff 0%, #ffffff 100%); overflow: hidden; text-align: center; }
.hero-bg-img { position: absolute; top: 0; left: 0; width: 100%; height: 100%; background-image: url('https://images.unsplash.com/photo-1451187580459-43490279c0fa?ixlib=rb-1.2.1&auto=format&fit=crop&w=1950&q=80'); background-size: cover; background-position: center; opacity: 0.1; z-index: 0; filter: grayscale(100%); }
.hero-content { position: relative; z-index: 2; max-width: 900px; margin: 0 auto; }
.hero-badge { display: inline-flex; align-items: center; gap: 8px; background: #eff6ff; border: 1px solid #dbeafe; color: var(--accent); padding: 8px 16px; border-radius: 50px; font-size: 0.85rem; font-weight: 600; margin-bottom: 32px; text-transform: uppercase; letter-spacing: 0.5px; }
.hero-badge::before { content: ''; width: 6px; height: 6px; background: var(--accent); border-radius: 50%; }
.hero h1 { font-size: 3.5rem; font-weight: 800; line-height: 1.1; margin-bottom: 24px; color: var(--primary); letter-spacing: -0.03em; }
.hero p { font-size: 1.25rem; color: var(--text-muted); margin-bottom: 40px; max-width: 650px; margin-left: auto; margin-right: auto; line-height: 1.6; }
.btn-hero { display: inline-flex; align-items: center; padding: 16px 40px; background: var(--accent); color: white; font-weight: 600; border-radius: 8px; font-size: 1.05rem; box-shadow: 0 10px 25px -5px rgba(37, 99, 235, 0.4); transition: 0.3s; }
.btn-hero:hover { background: var(--accent-hover); transform: translateY(-2px); box-shadow: 0 15px 30px -5px rgba(37, 99, 235, 0.5); }

/* --- 4. Security Bar --- */
.security-bar { background: #ffffff; padding: 20px 0 60px; border-bottom: 1px solid #e2e8f0; }
.sec-flex { display: flex; justify-content: center; gap: 60px; flex-wrap: wrap; }
.sec-item { display: flex; align-items: center; gap: 12px; font-weight: 600; color: var(--text-muted); font-size: 1rem; }
.sec-item svg { width: 22px; height: 22px; fill: var(--primary); opacity: 0.8; }

/* --- 5. Story --- */
.section-header { text-align: center; max-width: 700px; margin: 0 auto 60px; }
.section-header h2 { font-size: 2.25rem; color: var(--primary); margin-bottom: 16px; font-weight: 800; letter-spacing: -0.5px; }
.section-header p { font-size: 1.1rem; color: var(--text-muted); }
.story-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 80px; align-items: center; }
.story-text h3 { color: var(--accent); text-transform: uppercase; font-size: 0.85rem; letter-spacing: 1.2px; font-weight: 700; margin-bottom: 12px; }
.story-text h2 { font-size: 2.25rem; font-weight: 800; color: var(--primary); margin-bottom: 24px; line-height: 1.2; }
.story-text p { margin-bottom: 20px; color: var(--text-muted); font-size: 1.05rem; text-align: justify; }
.story-img { border-radius: 16px; overflow: hidden; box-shadow: 0 20px 40px -10px rgba(0,0,0,0.1); border: 1px solid #e2e8f0; }

/* --- 6. Features --- */
.features-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px; }
.feature-card { background: white; padding: 40px 32px; border-radius: 16px; border: 1px solid #e2e8f0; transition: 0.3s; box-shadow: 0 1px 3px rgba(0,0,0,0.05); }
.feature-card:hover { transform: translateY(-5px); border-color: var(--accent); box-shadow: 0 20px 25px -5px rgba(0,0,0,0.1); }
.icon-box { width: 56px; height: 56px; background: #eff6ff; color: var(--accent); border-radius: 14px; display: flex; align-items: center; justify-content: center; margin-bottom: 24px; }
.icon-box svg { width: 28px; height: 28px; fill: currentColor; }
.feature-card h3 { font-size: 1.25rem; font-weight: 700; margin-bottom: 12px; color: var(--primary); }
.feature-card p { font-size: 1rem; color: var(--text-muted); line-height: 1.6; }

/* --- 7. Contact --- */
.contact-box { display: grid; grid-template-columns: 380px 1fr; background: white; border-radius: 20px; overflow: hidden; border: 1px solid #e2e8f0; box-shadow: 0 20px 25px -5px rgba(0,0,0,0.1); }
.contact-info { padding: 60px; background: #f8fafc; border-right: 1px solid #e2e8f0; }
.contact-info h3 { font-size: 1.5rem; font-weight: 800; color: var(--primary); margin-bottom: 32px; }
.info-row { margin-bottom: 28px; }
.info-row label { display: block; font-size: 0.75rem; text-transform: uppercase; font-weight: 700; letter-spacing: 0.5px; color: #94a3b8; margin-bottom: 6px; }
.info-row p, .info-row a { font-size: 1.05rem; font-weight: 600; color: var(--primary); }
.info-row a { color: var(--accent); }
.contact-map iframe { width: 100%; height: 100%; min-height: 450px; border: 0; }

/* --- 8. Footer (Compact) --- */
footer { background-color: var(--bg-white); border-top: 1px solid #e2e8f0; padding: 24px 0; margin-top: auto; }
.footer-flex { display: flex; justify-content: space-between; align-items: center; }
.copyright { font-size: 0.85rem; color: var(--text-light); font-weight: 500; }
.footer-links { display: flex; gap: 24px; }
.footer-links a { font-size: 0.85rem; color: var(--text-muted); font-weight: 500; }
.footer-links a:hover { color: var(--primary); }

/* --- Privacy Page Specifics --- */
.back-link { color: #64748b; text-decoration: none; font-size: 0.95rem; font-weight: 500; transition: 0.2s; }
.back-link:hover { color: #2563eb; }
.page-header { border-bottom: 1px solid #e2e8f0; padding-bottom: 20px; margin-bottom: 40px; }
.page-header h2 { margin-top: 0; font-size: 2.2rem; color: #0f172a; font-weight: 800; letter-spacing: -0.02em; }
.last-updated { color: #64748b; font-size: 1rem; margin-top: 10px; }
main { padding: 60px 24px; max-width: 900px; margin: 0 auto; }
main p { margin-bottom: 24px; font-size: 16px; line-height: 1.6; color: #334155; text-align: justify; }
main strong { color: #0f172a; font-weight: 700; font-size: 16px; display: block; margin-bottom: 8px; margin-top: 32px; }
main p:first-of-type strong { margin-top: 0; }
main a { color: #2563eb; text-decoration: none; }
main a:hover { text-decoration: underline; }
.contact-box-privacy { background: #f8fafc; border: 1px solid #e2e8f0; padding: 35px; border-radius: 12px; margin-top: 40px; }
.contact-box-privacy p { margin-bottom: 10px; font-size: 16px; margin-top: 0; }
.contact-box-privacy strong { margin-top: 0; margin-bottom: 15px; font-size: 18px; color: #2563eb; display: block; }

/* Responsive */
@media (max-width: 1024px) {
    .nav-inner { grid-template-columns: 1fr auto; }
    .nav-menu { display: none; }
    .hero h1 { font-size: 2.8rem; }
    .story-grid, .features-grid, .contact-box { grid-template-columns: 1fr; }
    .footer-flex { flex-direction: column; gap: 15px; text-align: center; }
}