/* ===== BangBang HVAC - Global Styles ===== */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
:root{
  --primary:#0066CC;--primary-dark:#004999;--primary-light:#3388DD;
  --accent:#FF6B00;--accent-light:#FF8533;--accent-dark:#CC5500;
  --dark:#1A1A2E;--dark2:#16213E;--dark3:#0F3460;
  --gray:#F5F7FA;--gray2:#E8ECF1;--gray3:#CBD5E0;
  --text:#2D3748;--text2:#718096;--white:#FFFFFF;
  --max-w:1200px;
  --shadow:0 2px 12px rgba(0,0,0,.08);--shadow-lg:0 8px 30px rgba(0,0,0,.12);
  --radius:10px;--radius-lg:16px;
  --transition:all .3s ease;
  --font-zh:-apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei",sans-serif;
  --font-en:'Inter',-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;
}
html{scroll-behavior:smooth}
body{font-family:var(--font-zh);color:var(--text);line-height:1.7;background:var(--white);-webkit-font-smoothing:antialiased}
a{color:var(--primary);text-decoration:none;transition:var(--transition)}
a:hover{color:var(--primary-dark)}
img{max-width:100%;height:auto;display:block}
.container{max-width:var(--max-w);margin:0 auto;padding:0 20px}
h1,h2,h3,h4{font-weight:700;line-height:1.3;color:var(--dark)}
h1{font-size:clamp(28px,5vw,42px)}
h2{font-size:clamp(24px,4vw,34px)}
h3{font-size:clamp(20px,3vw,26px)}
p{margin-bottom:1em}

/* ===== Top Bar ===== */
.top-bar{background:var(--dark);color:var(--white);font-size:14px;padding:8px 0}
.top-bar .container{display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:8px}
.top-bar a{color:var(--accent);font-weight:600}
.top-bar .top-info{display:flex;gap:20px;align-items:center;flex-wrap:wrap}
.top-bar .top-info span{display:flex;align-items:center;gap:4px}

/* ===== Header ===== */
.site-header{background:var(--white);border-bottom:3px solid var(--primary);position:sticky;top:0;z-index:1000;box-shadow:var(--shadow)}
.header-inner{display:flex;justify-content:space-between;align-items:center;padding:12px 20px;max-width:var(--max-w);margin:0 auto}
.logo{font-size:22px;font-weight:800;color:var(--dark);display:flex;align-items:center;gap:8px}
.logo span{color:var(--accent)}
.logo small{font-size:12px;font-weight:400;color:var(--text2);display:block}
.main-nav{display:flex;align-items:center;gap:4px}
.main-nav a{padding:8px 14px;border-radius:6px;font-size:15px;color:var(--text);font-weight:500;transition:var(--transition)}
.main-nav a:hover,.main-nav a.active{background:var(--primary);color:var(--white)}
.header-cta{background:var(--accent);color:var(--white)!important;padding:10px 20px;border-radius:8px;font-weight:700;font-size:14px;display:flex;align-items:center;gap:6px;white-space:nowrap}
.header-cta:hover{background:var(--accent-dark);color:var(--white)!important}
.menu-toggle{display:none;background:none;border:2px solid var(--primary);color:var(--primary);padding:6px 12px;border-radius:6px;font-size:20px;cursor:pointer}

/* ===== Buttons ===== */
.btn{display:inline-flex;align-items:center;gap:8px;padding:14px 28px;border-radius:var(--radius);font-weight:600;font-size:15px;transition:var(--transition);cursor:pointer;border:none;text-align:center;justify-content:center}
.btn-primary{background:var(--primary);color:var(--white)}.btn-primary:hover{background:var(--primary-dark);color:var(--white)}
.btn-accent{background:var(--accent);color:var(--white)}.btn-accent:hover{background:var(--accent-dark);color:var(--white)}
.btn-outline{background:transparent;border:2px solid var(--primary);color:var(--primary)}.btn-outline:hover{background:var(--primary);color:var(--white)}
.btn-white{background:var(--white);color:var(--dark)}.btn-white:hover{background:var(--gray);color:var(--dark)}
.btn-lg{padding:16px 36px;font-size:17px}

/* ===== Hero ===== */
.hero{background:linear-gradient(135deg,var(--dark) 0%,var(--dark2) 50%,var(--dark3) 100%);color:var(--white);padding:80px 0 70px;position:relative;overflow:hidden}
.hero::before{content:'';position:absolute;right:-120px;top:-120px;width:500px;height:500px;background:rgba(255,107,0,.06);border-radius:50%}
.hero::after{content:'';position:absolute;left:-80px;bottom:-80px;width:300px;height:300px;background:rgba(0,102,204,.06);border-radius:50%}
.hero .container{position:relative;z-index:1}
.hero h1{margin-bottom:16px}.hero h1 span{color:var(--accent)}
.hero p{font-size:18px;color:#ccc;max-width:600px;margin-bottom:30px}
.hero-badges{display:flex;gap:12px;flex-wrap:wrap;margin-bottom:30px}
.hero-badge{background:rgba(255,255,255,.1);border:1px solid rgba(255,255,255,.15);padding:6px 16px;border-radius:20px;font-size:13px;color:#ddd;display:flex;align-items:center;gap:6px}
.hero-buttons{display:flex;gap:12px;flex-wrap:wrap}
.hero-stats{display:flex;gap:40px;margin-top:40px;flex-wrap:wrap}
.hero-stat{text-align:center}.hero-stat strong{display:block;font-size:2rem;color:var(--accent)}.hero-stat span{font-size:13px;color:#aaa}

/* ===== Sections ===== */
.section{padding:70px 0}
.section-gray{background:var(--gray)}
.section-header{text-align:center;margin-bottom:45px}
.section-header h2{margin-bottom:10px}
.section-header p{color:var(--text2);font-size:1.05rem;max-width:600px;margin:0 auto}
.section-header::after{content:'';display:block;width:50px;height:3px;background:var(--accent);margin:15px auto 0}

/* ===== Service Cards ===== */
.services-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:20px}
.service-card{background:var(--white);border:1px solid var(--gray2);border-radius:var(--radius-lg);padding:30px 24px;transition:var(--transition);position:relative;overflow:hidden}
.service-card:hover{box-shadow:var(--shadow-lg);transform:translateY(-4px);border-color:var(--primary)}
.service-card-icon{width:56px;height:56px;background:linear-gradient(135deg,var(--primary),var(--primary-light));color:var(--white);border-radius:12px;display:flex;align-items:center;justify-content:center;font-size:24px;margin-bottom:16px}
.service-card h3{font-size:1.1rem;margin-bottom:8px}
.service-card p{color:var(--text2);font-size:.9rem;margin-bottom:16px}
.service-card .card-link{color:var(--primary);font-weight:600;font-size:.9rem;display:flex;align-items:center;gap:4px}
.service-card .card-link:hover{gap:8px}

/* ===== Why Choose Us ===== */
.why-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:20px}
.why-card{text-align:center;padding:30px 20px;background:var(--white);border-radius:var(--radius-lg);box-shadow:var(--shadow)}
.why-card-icon{font-size:2.5rem;margin-bottom:12px}
.why-card h4{font-size:1rem;margin-bottom:8px;color:var(--dark)}
.why-card p{color:var(--text2);font-size:.9rem}

/* ===== FAQ ===== */
.faq-list{max-width:800px;margin:0 auto}
.faq-item{border:1px solid var(--gray2);border-radius:var(--radius);margin-bottom:12px;overflow:hidden}
.faq-item summary{padding:18px 24px;font-weight:600;cursor:pointer;list-style:none;display:flex;justify-content:space-between;align-items:center;transition:var(--transition)}
.faq-item summary:hover{background:var(--gray)}
.faq-item summary::after{content:'+';font-size:1.4rem;color:var(--primary);font-weight:300;transition:var(--transition)}
.faq-item[open] summary::after{content:'-'}
.faq-item[open] summary{background:var(--primary);color:var(--white)}
.faq-item[open] summary::after{color:var(--white)}
.faq-answer{padding:16px 24px;color:var(--text2);line-height:1.8}

/* ===== CTA Section ===== */
.cta-section{background:linear-gradient(135deg,var(--primary),var(--primary-dark));padding:60px 0;text-align:center;color:var(--white)}
.cta-section h2{color:var(--white);margin-bottom:10px}
.cta-section p{font-size:1.05rem;margin-bottom:25px;opacity:.9}
.cta-buttons{display:flex;justify-content:center;gap:12px;flex-wrap:wrap}

/* ===== BangBang CTA ===== */
.bangbang-cta{background:linear-gradient(135deg,var(--accent),var(--accent-dark));padding:50px 0;text-align:center;color:var(--white);position:relative}
.bangbang-cta h2{color:var(--white);margin-bottom:8px}
.bangbang-cta p{opacity:.9;margin-bottom:20px;font-size:1.05rem}

/* ===== Location Cards ===== */
.location-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(200px,1fr));gap:14px}
.location-card{display:block;background:var(--white);border:1px solid var(--gray2);border-radius:var(--radius);padding:20px;text-align:center;font-weight:600;color:var(--text);transition:var(--transition)}
.location-card:hover{border-color:var(--primary);box-shadow:var(--shadow);transform:translateY(-3px);color:var(--primary)}

/* ===== Blog Cards ===== */
.blog-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(320px,1fr));gap:24px}
.blog-card{background:var(--white);border:1px solid var(--gray2);border-radius:var(--radius-lg);overflow:hidden;transition:var(--transition)}
.blog-card:hover{box-shadow:var(--shadow-lg);transform:translateY(-3px)}
.blog-card-img{height:200px;background:linear-gradient(135deg,var(--dark2),var(--dark3));display:flex;align-items:center;justify-content:center;color:var(--accent);font-size:3rem}
.blog-card-body{padding:24px}
.blog-card-body h3{font-size:1.1rem;margin-bottom:8px}
.blog-card-body h3 a{color:var(--dark)}.blog-card-body h3 a:hover{color:var(--primary)}
.blog-card-body p{color:var(--text2);font-size:.9rem;margin-bottom:12px}
.blog-card-meta{font-size:.8rem;color:var(--text2)}

/* ===== Article ===== */
.article-content{max-width:800px;margin:0 auto}
.article-content h1{margin-bottom:16px}
.article-content h2{margin:32px 0 12px;font-size:1.5rem}
.article-content h3{margin:24px 0 10px;font-size:1.2rem}
.article-content p{margin-bottom:16px;line-height:1.9}
.article-content ul,.article-content ol{margin:16px 0;padding-left:24px}
.article-content li{margin-bottom:8px;line-height:1.8}
.article-meta{color:var(--text2);font-size:.9rem;margin-bottom:24px;padding-bottom:16px;border-bottom:1px solid var(--gray2)}
.article-tags{display:flex;gap:8px;flex-wrap:wrap;margin-top:24px}
.article-tags a{background:var(--gray);padding:4px 12px;border-radius:20px;font-size:.8rem;color:var(--text2)}

/* ===== Page Hero ===== */
.page-hero{background:linear-gradient(135deg,var(--dark) 0%,var(--dark2) 100%);color:var(--white);padding:60px 0 50px;text-align:center}
.page-hero h1{margin-bottom:10px}.page-hero h1 span{color:var(--accent)}
.page-hero p{color:#ccc;max-width:600px;margin:0 auto;font-size:1.05rem}
.breadcrumb{display:flex;justify-content:center;gap:8px;margin-bottom:16px;font-size:.85rem;color:#999}
.breadcrumb a{color:var(--accent)}

/* ===== Contact Form ===== */
.form-card{background:var(--white);border-radius:var(--radius-lg);padding:40px;box-shadow:var(--shadow-lg);max-width:600px;margin:0 auto}
.form-group{margin-bottom:20px}
.form-group label{display:block;font-weight:600;margin-bottom:6px;font-size:.9rem}
.form-group input,.form-group select,.form-group textarea{width:100%;padding:12px 16px;border:1px solid var(--gray2);border-radius:8px;font-size:15px;font-family:inherit;transition:var(--transition)}
.form-group input:focus,.form-group select:focus,.form-group textarea:focus{outline:none;border-color:var(--primary);box-shadow:0 0 0 3px rgba(0,102,204,.1)}

/* ===== Footer ===== */
.site-footer{background:var(--dark);color:#ccc;padding:50px 0 20px}
.footer-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:30px;margin-bottom:30px}
.site-footer h3{color:var(--accent);margin-bottom:16px;font-size:18px}
.site-footer a{color:#ccc;transition:var(--transition)}.site-footer a:hover{color:var(--accent)}
.footer-links{list-style:none;display:flex;flex-direction:column;gap:8px}
.footer-bottom{border-top:1px solid rgba(255,255,255,.1);padding-top:20px}
.partner-links{text-align:center;padding:12px 0 8px;border-top:1px solid rgba(255,255,255,.08);margin-bottom:16px}
.partner-links span{color:#999;font-size:13px}
.partner-links a{color:#ccc;margin:0 10px;font-size:13px}
.copyright{text-align:center;font-size:14px}

/* ===== Floating CTA ===== */
.floating-cta{position:fixed;bottom:20px;right:20px;z-index:999;display:flex;flex-direction:column;gap:10px}
.floating-btn{width:56px;height:56px;border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:24px;color:var(--white);box-shadow:0 4px 20px rgba(0,0,0,.25);transition:var(--transition);border:none;cursor:pointer}
.floating-btn.call{background:var(--accent)}
.floating-btn.quote{background:var(--primary)}
.floating-btn:hover{transform:scale(1.1)}

/* ===== Responsive ===== */
@media(max-width:768px){
  .main-nav{display:none;position:absolute;top:100%;left:0;right:0;background:var(--white);flex-direction:column;padding:16px;box-shadow:var(--shadow-lg);border-top:1px solid var(--gray2)}
  .main-nav.open{display:flex}
  .menu-toggle{display:block}
  .hero{padding:50px 0 40px}
  .hero-stats{gap:20px}
  .section{padding:50px 0}
  .services-grid{grid-template-columns:1fr}
  .blog-grid{grid-template-columns:1fr}
  .footer-grid{grid-template-columns:1fr}
  .header-cta{display:none}
  .header-inner{padding:10px 16px}
}
@media(max-width:480px){
  .hero h1{font-size:26px}
  .hero-buttons{flex-direction:column}
  .cta-buttons{flex-direction:column;align-items:center}
}