/* BangBang HVAC & Water Heater - Professional Styles */
:root {
  --primary: #1e40af;
  --primary-light: #3b82f6;
  --primary-dark: #1e3a8a;
  --orange: #f97316;
  --orange-light: #fb923c;
  --orange-dark: #ea580c;
  --dark: #111827;
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-500: #6b7280;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-800: #1f2937;
  --white: #ffffff;
  --success: #10b981;
  --danger: #ef4444;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 1px 3px rgba(0,0,0,.1);
  --shadow-md: 0 4px 6px rgba(0,0,0,.1);
  --shadow-lg: 0 10px 25px rgba(0,0,0,.12);
  --max-w: 1200px;
  --transition: .2s ease;
}
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif; color: var(--gray-800); line-height: 1.7; background: var(--white); }
a { color: var(--primary); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--orange); }
img { max-width: 100%; height: auto; }
.container { max-width: var(--max-w); margin: 0 auto; padding: 0 20px; }
.en { display: none; }
body.lang-en .zh { display: none !important; }
body.lang-en .en { display: inline !important; }
body.lang-en h1 .en, body.lang-en h2 .en, body.lang-en h3 .en, body.lang-en p .en, body.lang-en li .en, body.lang-en td .en, body.lang-en th .en { display: inline !important; }
body.lang-en span.en { display: inline !important; }
body.lang-en div.en { display: block !important; }

/* Notification Bar */
.notif-bar { background: var(--orange); color: white; text-align: center; padding: 10px 20px; font-size: 14px; }
.notif-bar a { color: white; background: var(--primary); padding: 4px 16px; border-radius: 20px; margin-left: 12px; font-weight: 600; }
.notif-bar a:hover { background: var(--primary-dark); }

/* Header */
.header { background: white; box-shadow: var(--shadow); position: sticky; top: 0; z-index: 100; }
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.logo { font-size: 22px; font-weight: 800; color: var(--dark); }
.logo span { color: var(--orange); }
.logo-icon { margin-right: 6px; }
.nav { display: flex; gap: 24px; }
.nav a { color: var(--gray-700); font-weight: 500; font-size: 15px; }
.nav a:hover { color: var(--primary); }
.header-cta { display: flex; align-items: center; gap: 12px; }
.phone-badge { background: var(--primary); color: white !important; padding: 6px 16px; border-radius: 24px; font-weight: 600; font-size: 14px; }
.phone-badge:hover { background: var(--primary-dark); color: white !important; }
.lang-btn { background: var(--gray-100); border: 1px solid var(--gray-300); padding: 4px 12px; border-radius: 16px; cursor: pointer; font-size: 13px; }
.btn { display: inline-block; padding: 10px 24px; border-radius: 24px; font-weight: 600; font-size: 15px; transition: all var(--transition); cursor: pointer; border: none; }
.btn-cta { background: var(--orange); color: white !important; }
.btn-cta:hover { background: var(--orange-dark); color: white !important; transform: translateY(-1px); }
.btn-primary { background: var(--primary); color: white !important; }
.btn-primary:hover { background: var(--primary-dark); color: white !important; }
.btn-outline { border: 2px solid white; color: white !important; background: transparent; }
.btn-outline:hover { background: white; color: var(--primary) !important; }
.btn-xl { padding: 16px 40px; font-size: 18px; }
.menu-toggle { display: none; background: none; border: none; cursor: pointer; padding: 8px; }
.menu-toggle span { display: block; width: 24px; height: 2px; background: var(--dark); margin: 5px 0; transition: var(--transition); }
.mobile-nav { display: none; background: white; border-top: 1px solid var(--gray-200); }
.mobile-nav.open { display: block; }
.mobile-nav a { display: block; padding: 12px 20px; color: var(--gray-700); border-bottom: 1px solid var(--gray-100); }

/* Breadcrumb */
.breadcrumb { background: var(--gray-50); padding: 12px 0; font-size: 14px; color: var(--gray-500); }
.breadcrumb a { color: var(--primary); }

/* Hero */
.hero, .service-hero { background: linear-gradient(135deg, var(--primary-dark), var(--primary)); color: white; padding: 60px 0 80px; text-align: center; }
.hero h1, .service-hero h1 { font-size: 42px; font-weight: 800; margin-bottom: 20px; line-height: 1.2; }
.accent-orange { color: var(--orange); }
.accent-blue { color: var(--primary-light); }
.hero-sub, .service-lead { font-size: 18px; max-width: 800px; margin: 0 auto 30px; opacity: .9; line-height: 1.8; }
.hero-badges, .trust-row { display: flex; flex-wrap: wrap; justify-content: center; gap: 12px; margin: 24px 0; }
.badge { background: rgba(255,255,255,.15); padding: 6px 16px; border-radius: 20px; font-size: 14px; font-weight: 500; }
.hero-pill { padding: 8px 20px; border-radius: 24px; font-size: 14px; font-weight: 600; }
.hero-pill-warm { background: rgba(249,115,22,.2); border: 1px solid rgba(249,115,22,.4); }
.hero-pill-blue { background: rgba(59,130,246,.2); border: 1px solid rgba(59,130,246,.4); }
.hero-search-wrap { max-width: 600px; margin: 0 auto 24px; display: flex; background: white; border-radius: 30px; overflow: hidden; box-shadow: var(--shadow-lg); }
.hero-search { flex: 1; border: none; padding: 14px 24px; font-size: 16px; outline: none; color: var(--dark); }
.hero-search-btn { background: var(--orange); color: white; border: none; padding: 14px 24px; cursor: pointer; font-size: 18px; }
.hero-chips { display: flex; flex-wrap: wrap; justify-content: center; gap: 8px; margin-bottom: 30px; }
.chip { background: rgba(255,255,255,.15); color: white; padding: 8px 18px; border-radius: 20px; font-size: 14px; border: 1px solid rgba(255,255,255,.25); transition: var(--transition); }
.chip:hover { background: rgba(255,255,255,.25); color: white; }
.hero-main-cta { margin-top: 20px; }
.hero-cta-note { display: block; margin-top: 10px; font-size: 13px; opacity: .8; }

/* Sections */
.section { padding: 60px 0; }
.section-alt { background: var(--gray-50); }
.section-title { font-size: 30px; font-weight: 700; text-align: center; margin-bottom: 40px; color: var(--dark); }
.section-title span.en { display: none; }

/* Service Cards */
.service-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.service-card { background: white; border-radius: var(--radius); padding: 32px 24px; box-shadow: var(--shadow); transition: var(--transition); border: 1px solid var(--gray-200); }
.service-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); border-color: var(--primary); }
.service-card .icon { font-size: 40px; margin-bottom: 16px; }
.service-card h3 { font-size: 18px; font-weight: 700; margin-bottom: 12px; color: var(--dark); }
.service-card p { font-size: 15px; color: var(--gray-600); margin-bottom: 16px; }
.service-card .price { color: var(--orange); font-weight: 700; font-size: 16px; }
.service-card .card-link { color: var(--primary); font-weight: 600; }

/* Content Layout */
.content-layout { display: grid; grid-template-columns: 1fr 320px; gap: 40px; padding: 40px 0; }
.content-main { min-width: 0; }
.content-main h2 { font-size: 24px; font-weight: 700; margin: 32px 0 16px; color: var(--dark); }
.content-main h3 { font-size: 20px; font-weight: 600; margin: 24px 0 12px; color: var(--gray-800); }
.content-main p { margin-bottom: 16px; color: var(--gray-700); line-height: 1.8; }
.content-main ul, .content-main ol { margin: 0 0 16px 24px; color: var(--gray-700); }
.content-main li { margin-bottom: 8px; line-height: 1.7; }

/* Sidebar */
.sidebar { position: sticky; top: 80px; }
.sidebar-cta { background: var(--primary); color: white; padding: 32px 24px; border-radius: var(--radius); text-align: center; }
.sidebar-cta h3 { font-size: 20px; margin-bottom: 12px; }
.sidebar-cta p { opacity: .9; margin-bottom: 20px; font-size: 14px; }
.sidebar-cta .btn { width: 100%; margin-bottom: 10px; display: block; }
.sidebar-links { background: var(--gray-50); padding: 24px; border-radius: var(--radius); margin-top: 20px; }
.sidebar-links h4 { font-size: 16px; font-weight: 700; margin-bottom: 12px; }
.sidebar-links a { display: block; padding: 8px 0; color: var(--primary); font-size: 14px; border-bottom: 1px solid var(--gray-200); }

/* Price Table */
.price-table { overflow-x: auto; margin: 20px 0; }
.price-table table { width: 100%; border-collapse: collapse; }
.price-table th { background: var(--primary); color: white; padding: 12px 16px; text-align: left; font-size: 14px; }
.price-table td { padding: 12px 16px; border-bottom: 1px solid var(--gray-200); font-size: 14px; }
.price-table tr:hover { background: var(--gray-50); }
td.price { color: var(--orange); font-weight: 700; white-space: nowrap; }

/* FAQ */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item { border: 1px solid var(--gray-200); border-radius: var(--radius-sm); margin-bottom: 12px; overflow: hidden; }
.faq-q { padding: 16px 20px; font-weight: 600; cursor: pointer; display: flex; justify-content: space-between; align-items: center; background: white; transition: var(--transition); }
.faq-q:hover { background: var(--gray-50); }
.faq-q::after { content: "+"; font-size: 20px; color: var(--primary); font-weight: 700; transition: var(--transition); }
.faq-q.open::after { content: "−"; }
.faq-a { padding: 0 20px; max-height: 0; overflow: hidden; transition: max-height .3s ease, padding .3s ease; color: var(--gray-600); line-height: 1.8; }
.faq-a.open { padding: 0 20px 20px; max-height: 500px; }

/* Steps */
.steps-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; text-align: center; }
.step { padding: 24px; }
.step-num { width: 56px; height: 56px; background: var(--primary); color: white; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 24px; font-weight: 700; margin: 0 auto 16px; }
.step h3 { font-size: 16px; margin-bottom: 8px; }
.step p { font-size: 14px; color: var(--gray-600); }

/* Testimonials */
.testimonial-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.testimonial-card { background: white; padding: 24px; border-radius: var(--radius); box-shadow: var(--shadow); border: 1px solid var(--gray-200); }
.testimonial-card .stars { color: var(--orange); margin-bottom: 12px; }
.testimonial-card p { font-style: italic; color: var(--gray-600); margin-bottom: 12px; font-size: 14px; line-height: 1.7; }
.testimonial-card .author { font-weight: 600; font-size: 14px; color: var(--dark); }

/* Location Cards */
.location-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.location-card { background: white; padding: 24px; border-radius: var(--radius); box-shadow: var(--shadow); text-align: center; border: 1px solid var(--gray-200); transition: var(--transition); }
.location-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-lg); }
.location-card h3 { font-size: 18px; margin-bottom: 8px; }
.location-card p { font-size: 14px; color: var(--gray-600); }

/* Blog Cards */
.blog-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.blog-card { background: white; border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow); border: 1px solid var(--gray-200); transition: var(--transition); }
.blog-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-lg); }
.blog-card-body { padding: 20px; }
.blog-card h3 { font-size: 16px; font-weight: 600; margin-bottom: 8px; line-height: 1.4; }
.blog-card h3 a { color: var(--dark); }
.blog-card h3 a:hover { color: var(--primary); }
.blog-card p { font-size: 14px; color: var(--gray-600); line-height: 1.6; }
.blog-card .meta { font-size: 12px; color: var(--gray-500); margin-top: 12px; }
.blog-tag { display: inline-block; background: var(--gray-100); padding: 2px 10px; border-radius: 12px; font-size: 12px; color: var(--primary); margin-right: 6px; }

/* Article */
.article-header { padding: 40px 0; text-align: center; }
.article-header h1 { font-size: 36px; max-width: 800px; margin: 0 auto 16px; }
.article-meta { font-size: 14px; color: var(--gray-500); }
.article-body { max-width: 800px; margin: 0 auto; padding: 40px 20px; }
.article-body h2 { font-size: 26px; margin: 36px 0 16px; color: var(--dark); border-bottom: 2px solid var(--gray-200); padding-bottom: 8px; }
.article-body h3 { font-size: 20px; margin: 28px 0 12px; color: var(--gray-800); }
.article-body p { margin-bottom: 18px; color: var(--gray-700); line-height: 1.9; font-size: 16px; }
.article-body ul, .article-body ol { margin: 0 0 18px 28px; }
.article-body li { margin-bottom: 8px; line-height: 1.8; font-size: 16px; color: var(--gray-700); }
.article-cta { background: var(--primary); color: white; padding: 32px; border-radius: var(--radius); text-align: center; margin: 40px 0; }
.article-cta h3 { font-size: 22px; margin-bottom: 12px; }
.article-cta p { opacity: .9; margin-bottom: 16px; }

/* Map placeholder */
.map-placeholder { background: var(--gray-100); border: 2px dashed var(--gray-300); border-radius: var(--radius); padding: 60px 20px; text-align: center; color: var(--gray-500); margin: 20px 0; }

/* Footer */
.footer { background: var(--dark); color: rgba(255,255,255,.8); padding: 50px 0 20px; }
.footer-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 40px; margin-bottom: 30px; }
.footer-col h4 { color: white; font-size: 16px; margin-bottom: 16px; }
.footer-col ul { list-style: none; }
.footer-col li { margin-bottom: 8px; }
.footer-col a { color: rgba(255,255,255,.7); font-size: 14px; }
.footer-col a:hover { color: var(--orange); }
.footer-bottom { border-top: 1px solid rgba(255,255,255,.1); padding-top: 20px; display: flex; justify-content: space-between; align-items: center; font-size: 13px; color: rgba(255,255,255,.5); }

/* Sticky Phone */
.sticky-phone { position: fixed; bottom: 0; left: 0; right: 0; background: var(--orange); text-align: center; padding: 12px; z-index: 200; }
.sticky-phone a { color: white; font-weight: 600; font-size: 16px; }

/* Feature list */
.feature-list { list-style: none; padding: 0; }
.feature-list li { display: flex; gap: 16px; padding: 16px 0; border-bottom: 1px solid var(--gray-200); }
.feature-icon { font-size: 28px; flex-shrink: 0; }

/* Trust Section */
.trust-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; text-align: center; }
.trust-item { padding: 24px; }
.trust-item .icon { font-size: 36px; margin-bottom: 12px; }
.trust-item h3 { font-size: 16px; margin-bottom: 6px; }
.trust-item p { font-size: 13px; color: var(--gray-600); }

/* Responsive */
@media (max-width: 1024px) {
  .service-grid, .testimonial-grid, .blog-grid { grid-template-columns: repeat(2, 1fr); }
  .content-layout { grid-template-columns: 1fr; }
  .sidebar { position: static; }
  .steps-grid { grid-template-columns: repeat(2, 1fr); }
  .trust-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 768px) {
  .nav, .header-cta .phone-badge, .header-cta .btn-cta { display: none; }
  .menu-toggle { display: block; }
  .hero h1, .service-hero h1 { font-size: 28px; }
  .hero-sub, .service-lead { font-size: 16px; }
  .service-grid, .testimonial-grid, .location-grid, .blog-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .footer-bottom { flex-direction: column; gap: 8px; text-align: center; }
  .section-title { font-size: 24px; }
  .steps-grid { grid-template-columns: 1fr; }
  .trust-grid { grid-template-columns: 1fr; }
  .content-main h2 { font-size: 20px; }
  body { padding-bottom: 50px; }
  .article-header h1 { font-size: 26px; }
}
@media print { .notif-bar, .sticky-phone, .header, .sidebar-cta { display: none; } }