/* ===== CSS变量与主题 ===== */
:root {
    --bg: #ffffff;
    --text: #1a1a2e;
    --primary: #2c3e50;
    --secondary: #e74c3c;
    --card-bg: #ffffff;
    --border: #e0e0e0;
    --shadow: 0 4px 20px rgba(0,0,0,0.08);
    --radius: 16px;
    --transition: 0.3s ease;
    --hero-bg: linear-gradient(135deg, #2c3e50 0%, #3498db 100%);
    --hero-text: #ffffff;
    --footer-bg: #1a1a2e;
    --footer-text: #ffffff;
    --navbar-bg: rgba(255,255,255,0.95);
    --hover-bg: #f0f0f0;
}

[data-theme="dark"] {
    --bg: #0f0f23;
    --text: #e0e0e0;
    --primary: #3498db;
    --secondary: #e74c3c;
    --card-bg: #1a1a2e;
    --border: #333;
    --shadow: 0 4px 20px rgba(0,0,0,0.3);
    --hero-bg: linear-gradient(135deg, #0f0f23 0%, #1a1a2e 100%);
    --hero-text: #e0e0e0;
    --footer-bg: #0f0f23;
    --footer-text: #e0e0e0;
    --navbar-bg: rgba(15,15,35,0.95);
    --hover-bg: #2a2a3e;
}

/* ===== 模板主题 ===== */
[data-template="modern"] { --primary: #2c3e50; --secondary: #e74c3c; }
[data-template="tech"] { --primary: #00d2ff; --secondary: #ff6b6b; }
[data-template="fashion"] { --primary: #e84393; --secondary: #fdcb6e; }
[data-template="food"] { --primary: #e17055; --secondary: #00b894; }

/* ===== 全局样式 ===== */
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    transition: background var(--transition), color var(--transition);
}
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }
a { color: var(--primary); text-decoration: none; transition: var(--transition); }
a:hover { color: var(--secondary); }
img { max-width: 100%; height: auto; display: block; border-radius: var(--radius); }
h1, h2, h3, h4 { line-height: 1.3; }

/* ===== 导航栏 ===== */
.navbar {
    position: fixed; top: 0; left: 0; right: 0;
    background: var(--navbar-bg);
    backdrop-filter: blur(12px);
    z-index: 1000;
    box-shadow: 0 2px 20px rgba(0,0,0,0.1);
    padding: 12px 0;
    transition: background var(--transition);
}
.navbar .container { display: flex; align-items: center; justify-content: space-between; }
.logo { font-size: 1.5rem; font-weight: 700; color: var(--primary); display: flex; align-items: center; gap: 8px; }
.nav-links { display: flex; align-items: center; gap: 24px; }
.nav-links a { font-weight: 500; padding: 8px 0; position: relative; }
.nav-links a.active::after { content: ''; position: absolute; bottom: 0; left: 0; right: 0; height: 3px; background: var(--secondary); border-radius: 3px; }
.nav-actions { display: flex; align-items: center; gap: 12px; }
.theme-toggle, .template-toggle { background: none; border: 2px solid var(--border); border-radius: 50%; width: 40px; height: 40px; display: flex; align-items: center; justify-content: center; cursor: pointer; font-size: 1.2rem; color: var(--text); transition: var(--transition); }
.theme-toggle:hover, .template-toggle:hover { background: var(--hover-bg); transform: scale(1.1); }
.hamburger { display: none; background: none; border: none; font-size: 1.5rem; color: var(--text); cursor: pointer; }

/* ===== 按钮 ===== */
.btn-primary, .btn-outline, .btn-secondary {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 12px 28px; border-radius: 50px; font-weight: 600;
    transition: var(--transition); cursor: pointer; border: none;
}
.btn-primary { background: var(--primary); color: white; }
.btn-primary:hover { background: var(--secondary); transform: translateY(-2px); box-shadow: 0 8px 25px rgba(0,0,0,0.2); }
.btn-outline { background: transparent; border: 2px solid var(--primary); color: var(--primary); }
.btn-outline:hover { background: var(--primary); color: white; }
.btn-secondary { background: rgba(255,255,255,0.2); color: var(--hero-text); border: 2px solid rgba(255,255,255,0.5); }
.btn-secondary:hover { background: rgba(255,255,255,0.3); transform: translateY(-2px); }

/* ===== 英雄区 ===== */
.hero {
    min-height: 90vh;
    background: var(--hero-bg);
    color: var(--hero-text);
    display: flex; align-items: center;
    padding: 120px 0 80px;
    position: relative;
    overflow: hidden;
}
.hero .container { display: grid; grid-template-columns: 1fr 1fr; gap: 60px; align-items: center; }
.hero-content h1 { font-size: 3rem; font-weight: 800; margin-bottom: 20px; line-height: 1.2; }
.hero-content p { font-size: 1.2rem; opacity: 0.9; margin-bottom: 32px; max-width: 500px; }
.hero-buttons { display: flex; gap: 16px; flex-wrap: wrap; }
.hero-image img { width: 100%; border-radius: 24px; box-shadow: 0 20px 60px rgba(0,0,0,0.3); transform: perspective(800px) rotateY(-5deg); transition: var(--transition); }
.hero-image img:hover { transform: perspective(800px) rotateY(0deg); }

/* ===== 搜索筛选 ===== */
.search-filter { padding: 60px 0; background: var(--bg); }
.search-filter h2 { text-align: center; margin-bottom: 32px; font-size: 2rem; }
.filter-bar { display: flex; gap: 16px; flex-wrap: wrap; justify-content: center; margin-bottom: 16px; }
.search-box { position: relative; flex: 1; min-width: 250px; max-width: 400px; }
.search-box i { position: absolute; left: 16px; top: 50%; transform: translateY(-50%); color: #999; }
.search-box input { width: 100%; padding: 14px 20px 14px 48px; border: 2px solid var(--border); border-radius: 50px; background: var(--card-bg); color: var(--text); font-size: 1rem; transition: var(--transition); }
.search-box input:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 4px rgba(52,152,219,0.2); }
.filter-group { display: flex; gap: 12px; flex-wrap: wrap; }
.filter-group select { padding: 12px 20px; border: 2px solid var(--border); border-radius: 50px; background: var(--card-bg); color: var(--text); cursor: pointer; transition: var(--transition); }
.filter-group select:focus { outline: none; border-color: var(--primary); }
.active-filters { display: flex; gap: 8px; flex-wrap: wrap; justify-content: center; min-height: 40px; }

/* ===== 项目展示 ===== */
.projects { padding: 80px 0; background: var(--bg); }
.section-header { text-align: center; margin-bottom: 48px; }
.section-header h2 { font-size: 2.5rem; margin-bottom: 12px; }
.section-header p { color: #888; font-size: 1.1rem; }
.project-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 30px;
}
.project-card {
    background: var(--card-bg);
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
    cursor: pointer;
    border: 1px solid var(--border);
}
.project-card:hover { transform: translateY(-8px); box-shadow: 0 12px 40px rgba(0,0,0,0.15); }
.card-image { position: relative; overflow: hidden; height: 220px; }
.card-image img { width: 100%; height: 100%; object-fit: cover; transition: var(--transition); }
.project-card:hover .card-image img { transform: scale(1.08); }
.card-overlay {
    position: absolute; top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(0,0,0,0.5);
    display: flex; flex-direction: column; justify-content: space-between;
    padding: 16px; opacity: 0; transition: var(--transition);
}
.project-card:hover .card-overlay { opacity: 1; }
.card-category { background: var(--secondary); color: white; padding: 4px 12px; border-radius: 20px; font-size: 0.85rem; align-self: flex-start; }
.card-actions { display: flex; gap: 8px; justify-content: flex-end; }
.btn-view { background: white; color: var(--text); padding: 8px 20px; border-radius: 20px; font-weight: 600; }
.btn-share { background: rgba(255,255,255,0.9); border: none; border-radius: 50%; width: 40px; height: 40px; display: flex; align-items: center; justify-content: center; cursor: pointer; color: var(--text); }
.card-body { padding: 20px; }
.card-body h3 { font-size: 1.2rem; margin-bottom: 8px; }
.card-body p { color: #888; font-size: 0.9rem; margin-bottom: 12px; }
.card-meta { display: flex; justify-content: space-between; align-items: center; margin-bottom: 12px; }
.price { font-weight: 700; color: var(--secondary); font-size: 1.1rem; }
.rating { color: #f39c12; }
.card-tags { display: flex; gap: 6px; flex-wrap: wrap; }
.tag { background: var(--hover-bg); padding: 4px 12px; border-radius: 20px; font-size: 0.8rem; color: var(--text); }

/* ===== 服务特色 ===== */
.features { padding: 80px 0; background: var(--bg); }
.features-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 30px; }
.feature-card {
    text-align: center; padding: 40px 20px;
    background: var(--card-bg); border-radius: var(--radius);
    box-shadow: var(--shadow); transition: var(--transition);
    border: 1px solid var(--border);
}
.feature-card:hover { transform: translateY(-5px); }
.feature-card i { font-size: 2.5rem; color: var(--primary); margin-bottom: 16px; }

/* ===== 数据统计 ===== */
.stats { padding: 60px 0; background: var(--primary); color: white; }
.stats .container { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 30px; text-align: center; }
.stat-item { padding: 20px; }
.stat-number { font-size: 3rem; font-weight: 800; display: block; }
.stat-label { font-size: 1rem; opacity: 0.8; }

/* ===== 热力图 ===== */
.heatmap { padding: 60px 0; background: var(--bg); }
.heatmap h2 { text-align: center; margin-bottom: 32px; }
.heatmap-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
    gap: 8px;
    max-width: 800px;
    margin: 0 auto;
}
.heatmap-item {
    aspect-ratio: 1;
    border-radius: 8px;
    display: flex; align-items: center; justify-content: center;
    font-size: 0.8rem; font-weight: 600;
    transition: var(--transition);
    cursor: default;
}
.heatmap-item:hover { transform: scale(1.05); }

/* ===== 页脚 ===== */
.footer { background: var(--footer-bg); color: var(--footer-text); padding: 60px 0 20px; }
.footer-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 40px; margin-bottom: 40px; }
.footer-brand h3 { font-size: 1.5rem; margin-bottom: 16px; }
.social-links { display: flex; gap: 12px; margin-top: 16px; }
.social-links a { color: var(--footer-text); font-size: 1.5rem; transition: var(--transition); }
.social-links a:hover { color: var(--secondary); transform: translateY(-3px); }
.footer-links h4 { margin-bottom: 16px; }
.footer-links a { display: block; color: #aaa; margin-bottom: 8px; }
.footer-links a:hover { color: white; }
.footer-contact p { margin-bottom: 8px; color: #aaa; }
.footer-bottom { border-top: 1px solid #333; padding-top: 20px; text-align: center; color: #888; display: flex; justify-content: space-between; flex-wrap: wrap; gap: 12px; }
.footer-bottom a { color: #aaa; }
.footer-bottom a:hover { color: white; }

/* ===== 响应式 ===== */
@media (max-width: 768px) {
    .hamburger { display: block; }
    .nav-links {
        display: none;
        position: fixed; top: 70px; left: 0; right: 0;
        background: var(--navbar-bg); backdrop-filter: blur(12px);
        flex-direction: column; padding: 20px; gap: 16px;
        box-shadow: 0 4px 20px rgba(0,0,0,0.1);
    }
    .nav-links.active { display: flex; }
    .hero .container { grid-template-columns: 1fr; text-align: center; }
    .hero-content h1 { font-size: 2rem; }
    .hero-content p { margin: 0 auto 32px; }
    .hero-buttons { justify-content: center; }
    .hero-image { display: none; }
    .filter-bar { flex-direction: column; align-items: stretch; }
    .search-box { max-width: 100%; }
    .filter-group { flex-direction: column; }
    .project-grid { grid-template-columns: 1fr; }
    .features-grid { grid-template-columns: 1fr; }
    .stats .container { grid-template-columns: repeat(2, 1fr); }
    .footer-grid { grid-template-columns: 1fr; }
    .footer-bottom { flex-direction: column; text-align: center; }
}

@media (max-width: 480px) {
    .hero-content h1 { font-size: 1.6rem; }
    .section-header h2 { font-size: 1.8rem; }
    .project-grid { gap: 16px; }
}

/* ===== 滚动动画 ===== */
.fade-in { opacity: 0; transform: translateY(30px); transition: opacity 0.6s ease, transform 0.6s ease; }
.fade-in.visible { opacity: 1; transform: translateY(0); }