/* ============================================
   AooPower Design System v4.1 - Unified Clean Light
   Last updated: 2026-03-27
   ============================================ */

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

:root{
  --primary:#2563eb;
  --primary-dark:#1d4ed8;
  --secondary:#7c3aed;
  --success:#059669;
  --danger:#dc2626;
  --warning:#d97706;
  --bg:#f8fafc;
  --card-bg:#ffffff;
  --text:#1e293b;
  --text-light:#64748b;
  --text-lighter:#94a3b8;
  --border:#e2e8f0;
  --border-light:#f1f5f9;
  --shadow:0 4px 6px -1px rgba(0,0,0,0.1);
  --shadow-lg:0 10px 15px -3px rgba(0,0,0,0.1);
  --shadow-xl:0 20px 25px -5px rgba(0,0,0,0.1);
  --radius:12px;
  --radius-lg:16px;
  --max-w:1200px;
  --max-w-narrow:900px;
  --max-w-content:800px;
  --font:-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,'Helvetica Neue',Arial,sans-serif;
}

html{scroll-behavior:smooth}
body{font-family:var(--font);background:var(--bg);color:var(--text);line-height:1.6;-webkit-font-smoothing:antialiased}
a{color:var(--primary);text-decoration:none}
a:hover{text-decoration:underline}
img{max-width:100%;height:auto}

/* ===== 导航栏 ===== */
.navbar{background:var(--card-bg);border-bottom:1px solid var(--border);position:sticky;top:0;z-index:1000;box-shadow:0 1px 3px rgba(0,0,0,.08)}
.nav-inner{max-width:var(--max-w);margin:0 auto;padding:0 1.5rem;display:flex;justify-content:space-between;align-items:center;height:60px}
.nav-logo{font-size:1.5rem;font-weight:800;background:linear-gradient(135deg,var(--primary),var(--secondary));-webkit-background-clip:text;-webkit-text-fill-color:transparent;text-decoration:none}
.nav-logo:hover{text-decoration:none}
.nav-center{display:flex;align-items:center;gap:2rem}
.nav-links{display:flex;gap:1.75rem;list-style:none}
.nav-links a{color:var(--text);text-decoration:none;font-weight:500;font-size:.95rem;padding:.5rem 0;border-bottom:2px solid transparent;transition:all .2s}
.nav-links a:hover,.nav-links a.active{color:var(--primary);border-bottom-color:var(--primary);text-decoration:none}
.nav-right{display:flex;align-items:center;gap:1rem}
.lang-switch{display:flex;gap:2px;background:var(--border-light);border-radius:8px;padding:2px}
.lang-switch a{color:var(--text-light);text-decoration:none;font-size:13px;font-weight:600;padding:4px 10px;border-radius:6px;transition:all .2s}
.lang-switch a:hover{color:var(--text);text-decoration:none}
.lang-switch a.active{color:var(--primary);background:var(--card-bg);box-shadow:0 1px 2px rgba(0,0,0,.08)}
.nav-mobile-toggle{display:none;background:none;border:none;font-size:1.5rem;cursor:pointer;color:var(--text);padding:.5rem}

@media(max-width:768px){
  .nav-center{display:none}.nav-mobile-toggle{display:block}.nav-inner{height:52px;padding:0 1rem}
  .navbar.open .nav-center{display:flex;flex-direction:column;position:absolute;top:52px;left:0;right:0;background:var(--card-bg);border-bottom:1px solid var(--border);padding:1rem;box-shadow:var(--shadow-lg);z-index:999}
  .navbar.open .nav-links{flex-direction:column;gap:0}.navbar.open .nav-links a{padding:.75rem 0;border-bottom:1px solid var(--border-light)}
}

/* ===== 面包屑 ===== */
.breadcrumb{max-width:var(--max-w);margin:0 auto;padding:1rem 1.5rem;font-size:.85rem;color:var(--text-light)}
.breadcrumb a{color:var(--primary);text-decoration:none}.breadcrumb a:hover{text-decoration:underline}
.breadcrumb span{margin:0 .5rem;color:var(--border)}

/* ===== Hero 区域 ===== */
.hero{background:linear-gradient(135deg,var(--primary),var(--secondary));color:#fff;padding:4rem 1.5rem;text-align:center;margin:1.5rem auto;max-width:var(--max-w);border-radius:var(--radius-lg)}
.hero-inner h1{font-size:2.5rem;font-weight:800;margin-bottom:1rem;color:#fff}
.hero-inner p{font-size:1.25rem;opacity:0.9;margin-bottom:2rem}
.hero-features{display:flex;gap:1rem;justify-content:center;flex-wrap:wrap}
.feature-badge{background:rgba(255,255,255,0.2);padding:0.75rem 1.5rem;border-radius:8px;font-weight:500}

/* ===== Section Titles ===== */
.section-title{font-size:1.5rem;font-weight:700;color:var(--text);margin:2rem 0 1.5rem;text-align:center;padding-bottom:0.5rem}

/* ===== Tools Section ===== */
.tools-section{max-width:var(--max-w);margin:3rem auto;padding:0 1.5rem}
.tools-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(250px,1fr));gap:1.5rem}
.tool-card{background:var(--card-bg);padding:1.5rem;border-radius:var(--radius);box-shadow:var(--shadow);text-decoration:none;color:inherit;transition:transform 0.2s;border:1px solid var(--border)}
.tool-card:hover{transform:translateY(-4px);box-shadow:var(--shadow-lg);border-color:var(--primary);text-decoration:none}
.tool-icon{font-size:2.5rem;margin-bottom:0.75rem}
.tool-name{font-size:1.2rem;font-weight:600;margin-bottom:0.5rem;color:var(--text)}
.tool-desc{font-size:0.9rem;color:var(--text-light);line-height:1.5}
.section-footer{text-align:center;margin:2.5rem 0}

/* ===== Features Section ===== */
.features{max-width:var(--max-w);margin:3rem auto;padding:0 1.5rem}
.features-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(250px,1fr));gap:2rem}
.feature-item{text-align:center}
.feature-icon{font-size:3rem;margin-bottom:1rem}
.feature-item h3{font-size:1.2rem;font-weight:600;margin-bottom:0.5rem;color:var(--text)}
.feature-item p{color:var(--text-light);line-height:1.6}

/* ===== Internal Links ===== */
.internal-links{max-width:var(--max-w);margin:3rem auto;padding:0 1.5rem}
.links-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:1rem;text-align:center}
.link-card{color:var(--primary);text-decoration:none;padding:1rem;background:var(--card-bg);border-radius:var(--radius);border:1px solid var(--border);transition:all 0.2s;font-weight:500}
.link-card:hover{transform:translateY(-2px);box-shadow:var(--shadow);border-color:var(--primary);text-decoration:none}

/* ===== Content Pages ===== */
.content-wrapper{max-width:var(--max-w-content);margin:2rem auto;padding:0 1.5rem;line-height:1.8}
.content-wrapper h2{font-size:1.5rem;font-weight:700;color:var(--text);margin:2rem 0 1rem;padding-bottom:0.5rem;border-bottom:2px solid var(--border)}
.content-wrapper h3{font-size:1.2rem;font-weight:600;color:var(--text);margin:1.5rem 0 0.75rem}
.content-wrapper p{margin:0.75rem 0;color:var(--text-light)}
.content-wrapper ul,.content-wrapper ol{margin:0.75rem 0 1rem 1.5rem;color:var(--text-light)}
.content-wrapper li{margin:0.5rem 0;line-height:1.7}
.content-wrapper a{color:var(--primary)}

/* ===== FAQ Pages ===== */
.faq-section{max-width:var(--max-w-narrow);margin:2rem auto;padding:0 1.5rem}
.faq-item{background:var(--card-bg);padding:1.5rem;border-radius:var(--radius);margin-bottom:1rem;border:1px solid var(--border);transition:all 0.2s}
.faq-item:hover{border-color:var(--primary);box-shadow:var(--shadow)}
.faq-item h3{font-size:1.1rem;font-weight:600;color:var(--text);margin-bottom:0.75rem}
.faq-item p{color:var(--text-light);line-height:1.7}

/* ===== Contact Form ===== */
.contact-form{max-width:600px;margin:2rem auto;padding:2rem;background:var(--card-bg);border-radius:var(--radius-lg);box-shadow:var(--shadow)}
.contact-form h2{margin-bottom:1.5rem;text-align:center;color:var(--text)}
.contact-form input,.contact-form textarea{width:100%;padding:0.75rem;border:2px solid var(--border);border-radius:8px;font-size:16px;font-family:var(--font);margin-bottom:1rem;transition:border-color 0.2s}
.contact-form input:focus,.contact-form textarea:focus{outline:none;border-color:var(--primary)}

/* ===== Tool Pages ===== */
.tool-wrap{max-width:var(--max-w-narrow);margin:1.5rem auto;padding:0 1rem}
.tool-container{background:var(--card-bg);border-radius:var(--radius-lg);box-shadow:var(--shadow-xl);overflow:hidden}
.tool-header{color:#fff;padding:2rem 1.5rem;text-align:center}
.tool-header h1{font-size:1.5rem;font-weight:700;margin-bottom:.5rem}
.tool-header p{font-size:.9rem;opacity:.9}
.tool-body{padding:1.5rem}

/* 表单 */
.field{margin-bottom:1rem}
.field label{display:block;margin-bottom:.375rem;font-weight:600;font-size:.875rem;color:var(--text)}
.field input,.field select,.field textarea{width:100%;padding:.75rem 1rem;border:2px solid var(--border);border-radius:10px;font-size:.95rem;font-family:var(--font);transition:border-color .2s;background:#fff;color:var(--text)}
.field input:focus,.field select:focus,.field textarea:focus{outline:none;border-color:var(--primary);box-shadow:0 0 0 3px rgba(37,99,235,.08)}
.field-row{display:grid;grid-template-columns:1fr 1fr;gap:1rem}

/* 按钮 */
.btn-primary{display:inline-block;width:100%;padding:1rem;background:linear-gradient(135deg,var(--primary),var(--secondary));color:#fff;border:none;border-radius:10px;cursor:pointer;font-size:1.05rem;font-weight:600;font-family:var(--font);margin:.75rem 0 1.25rem;transition:opacity .2s;text-align:center}
.btn-primary:hover{opacity:.92;text-decoration:none}
.btn-primary:hover{text-decoration:none}

/* 结果 */
.result-hero{padding:1.5rem;border-radius:var(--radius-lg);text-align:center;margin-bottom:1.25rem}
.result-value{font-size:2.25rem;font-weight:800}
.result-label{font-size:.85rem;color:var(--text-light);margin:.25rem 0}
.metric-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(140px,1fr));gap:.75rem;margin:1rem 0}
.metric-card{background:var(--bg);padding:1rem;border-radius:var(--radius);text-align:center}
.metric-card .val{font-size:1.25rem;font-weight:700}
.metric-card .lbl{font-size:.75rem;color:var(--text-light);margin-top:.25rem}

/* 表格 */
.data-table{width:100%;border-collapse:collapse;margin:1rem 0}
.data-table th,.data-table td{padding:.625rem .75rem;text-align:left;border-bottom:1px solid var(--border-light);font-size:.875rem}
.data-table th{background:var(--bg);font-weight:600;font-size:.8rem;text-transform:uppercase;letter-spacing:.03em;color:var(--text-light)}
.data-table tr:hover{background:var(--border-light)}

/* 广告 */
.ad-slot{background:var(--border-light);border-radius:8px;padding:.75rem;text-align:center;margin:1.5rem 0;min-height:90px}
.hidden{display:none}

/* ===== SEO 内容 ===== */
.seo-content{max-width:var(--max-w-narrow);margin:2.5rem auto;padding:0 1.5rem;line-height:1.85;color:#444}
.seo-content h2{font-size:1.35rem;font-weight:700;color:var(--text);margin:2rem 0 .75rem;padding-bottom:.5rem;border-bottom:2px solid var(--border)}
.seo-content h3{font-size:1.05rem;font-weight:600;color:var(--text);margin:1.5rem 0 .5rem}
.seo-content p{margin:.75rem 0}
.seo-content ul,.seo-content ol{margin:.5rem 0 1rem 1.5rem;line-height:1.9}
.seo-content a{color:var(--primary)}
.faq-item{margin-bottom:1.25rem}

/* ===== 文章页 ===== */
.article-wrap{max-width:var(--max-w-content);margin:0 auto;padding:0 1.5rem}
.article-header{padding:2rem 0 1.5rem}
.article-header h1{font-size:2rem;font-weight:800;line-height:1.3;margin-bottom:1rem;color:var(--text)}
.article-meta{display:flex;gap:1.5rem;color:var(--text-light);font-size:.85rem;flex-wrap:wrap}
.article-body{background:var(--card-bg);border-radius:var(--radius-lg);padding:2.5rem;box-shadow:var(--shadow);margin-bottom:2rem}
.article-body h2{font-size:1.5rem;font-weight:700;color:var(--text);margin:2rem 0 1rem;padding-bottom:.5rem;border-bottom:2px solid var(--border)}
.article-body h3{font-size:1.2rem;font-weight:600;color:var(--text);margin:1.75rem 0 .75rem}
.article-body p{margin:.875rem 0;line-height:1.8;color:#444}
.article-body ul,.article-body ol{margin:.75rem 0 1rem 1.5rem}
.article-body li{margin:.5rem 0;line-height:1.7}
.article-body a{color:var(--primary)}
.article-body table{width:100%;border-collapse:collapse;margin:1.5rem 0}
.article-body th,.article-body td{border:1px solid var(--border);padding:.75rem;text-align:left;font-size:.9rem}
.article-body th{background:var(--bg);font-weight:600}
.article-body blockquote{border-left:4px solid var(--primary);padding:1rem 1.5rem;margin:1.5rem 0;background:var(--border-light);border-radius:0 8px 8px 0;color:var(--text-light);font-style:italic}
.article-body code{background:var(--bg);padding:.15rem .4rem;border-radius:4px;font-size:.875rem}
.article-body pre{background:var(--text);color:#e2e8f0;padding:1.25rem;border-radius:8px;overflow-x:auto;margin:1rem 0;font-size:.85rem;line-height:1.6}

/* 相关 */
.related-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:1rem;margin:1rem 0}
.related-card{background:var(--card-bg);border:1px solid var(--border);border-radius:var(--radius);padding:1.25rem;text-decoration:none;color:var(--text);transition:all .2s;display:block}
.related-card:hover{transform:translateY(-2px);box-shadow:var(--shadow);border-color:var(--primary);text-decoration:none}
.related-card h4{font-size:.95rem;font-weight:600;margin-bottom:.5rem;color:var(--text)}
.related-card p{font-size:.8rem;color:var(--text-light);line-height:1.5}

/* ===== 页脚 ===== */
.site-footer{background:var(--text);color:rgba(255,255,255,.9);padding:3rem 1.5rem 2rem;margin-top:4rem}
.footer-inner{max-width:var(--max-w);margin:0 auto}
.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr 1fr;gap:2rem;margin-bottom:2rem}
.footer-brand .footer-logo{font-size:1.25rem;font-weight:700;margin-bottom:.75rem}
.footer-brand p{font-size:.85rem;opacity:.7;line-height:1.6}
.footer-col h4{font-size:.85rem;font-weight:600;text-transform:uppercase;letter-spacing:.05em;margin-bottom:1rem;opacity:.9}
.footer-col ul{list-style:none}.footer-col li{margin-bottom:.5rem}
.footer-col a{color:rgba(255,255,255,.7);font-size:.9rem;text-decoration:none;transition:opacity .2s}
.footer-col a:hover{opacity:1;color:#fff}
.footer-bottom{border-top:1px solid rgba(255,255,255,.15);padding-top:1.5rem;display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:1rem}
.footer-bottom p{font-size:.8rem;opacity:.6}
.footer-bottom-links{display:flex;gap:1.5rem}
.footer-bottom-links a{color:rgba(255,255,255,.6);font-size:.8rem;text-decoration:none}
.footer-bottom-links a:hover{opacity:1;color:#fff}

/* ===== 响应式 ===== */
@media(max-width:768px){
  .hero{padding:3rem 1rem}.hero-inner h1{font-size:2rem}
  .tool-wrap{padding:0 .75rem;margin:1rem auto}.tool-header{padding:1.5rem 1rem}.tool-header h1{font-size:1.25rem}.tool-body{padding:1rem}
  .field-row{grid-template-columns:1fr}
  .field input,.field select,.field textarea{font-size:16px;padding:.875rem 1rem}
  .btn-primary{padding:.875rem;font-size:1rem;min-height:48px}
  .result-value{font-size:1.75rem}.metric-grid{grid-template-columns:1fr 1fr}
  .data-table{display:block;overflow-x:auto;-webkit-overflow-scrolling:touch}
  .article-body{padding:1.5rem}.article-header h1{font-size:1.5rem}
  .article-wrap{padding:0 1rem}.seo-content{padding:0 1rem}.breadcrumb{padding:.75rem 1rem}
  .footer-grid{grid-template-columns:1fr 1fr;gap:1.5rem}.footer-bottom{flex-direction:column;text-align:center}
  .related-grid{grid-template-columns:1fr}
  .content-wrapper{padding:0 1rem}
  .faq-section{padding:0 1rem}
  .contact-form{padding:1.5rem;margin:1.5rem auto}
}
@media(max-width:480px){
  .metric-grid{grid-template-columns:1fr}.footer-grid{grid-template-columns:1fr}
  .hero-inner h1{font-size:1.75rem}
  .tools-grid{grid-template-columns:1fr}
  .features-grid{grid-template-columns:1fr}
  .links-grid{grid-template-columns:1fr}
}