/* ============================================
   大连博塔实验室科技 - 城市分站 V3 全屏大气版
   ============================================ */
:root{
  --bt-primary:#1a6dcc;--bt-primary-dark:#0e4f99;--bt-primary-light:#eaf2fd;
  --bt-accent:#e8590c;--bt-accent-dark:#c94d08;--bt-accent-light:#fff5ef;
  --bt-navy:#0f1c2e;--bt-navy-light:#1a2d42;
  --bt-text:#333;--bt-text-light:#777;--bt-text-muted:#999;
  --bt-bg:#f5f7fa;--bt-white:#fff;--bt-border:#e5e9ef;
  --bt-shadow:0 4px 20px rgba(0,0,0,.06);--bt-shadow-lg:0 16px 48px rgba(0,0,0,.12);
  --bt-radius:8px;--bt-radius-lg:12px;
  --bt-container:1200px;--bt-container-wide:1400px;
  --bt-header-h:76px;--bt-nav-h:48px;--bt-topbar-h:36px;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{font-family:"Microsoft YaHei","PingFang SC","Helvetica Neue",Arial,sans-serif;color:var(--bt-text);background:var(--bt-white);line-height:1.7;-webkit-font-smoothing:antialiased;overflow-x:hidden}
a{color:var(--bt-primary);transition:all .3s;text-decoration:none}a:hover{color:var(--bt-primary-dark);text-decoration:none}
h1,h2,h3,h4,h5,h6{color:var(--bt-navy);font-weight:700;margin-top:0;line-height:1.4}
img{max-width:100%;height:auto}
ul{list-style:none;padding:0;margin:0}
.bt-container{max-width:var(--bt-container);margin:0 auto;padding:0 20px}
.bt-container-wide{max-width:var(--bt-container-wide);margin:0 auto;padding:0 20px}

/* ====================== TOPBAR ====================== */
.bt-topbar{background:var(--bt-navy);color:rgba(255,255,255,.55);font-size:13px;height:var(--bt-topbar-h);position:relative;z-index:200}
.bt-topbar-inner{max-width:var(--bt-container-wide);margin:0 auto;padding:0 20px;display:flex;justify-content:space-between;align-items:center;height:100%}
.bt-topbar-left{display:flex;align-items:center;gap:16px}
.bt-topbar-right{display:flex;align-items:center;gap:4px}
.bt-topbar-right a{color:rgba(255,255,255,.55);font-size:13px;padding:4px 12px;border-radius:4px;transition:all .2s}
.bt-topbar-right a:hover{color:#fff;background:rgba(255,255,255,.08)}
.bt-topbar-welcome{font-size:12px}
.bt-city-badge{display:inline-flex;align-items:center;gap:5px;background:linear-gradient(135deg,rgba(26,109,204,.3),rgba(26,109,204,.15));color:#7db8f5;padding:3px 14px;border-radius:20px;font-size:12px;font-weight:600;border:1px solid rgba(26,109,204,.3)}

/* ====================== HEADER ====================== */
.bt-header{background:var(--bt-white);height:var(--bt-header-h);position:sticky;top:0;z-index:160;transition:all .3s}
.bt-header-inner{max-width:var(--bt-container-wide);margin:0 auto;padding:0 20px;display:flex;align-items:center;justify-content:space-between;height:100%;gap:20px}
.bt-header-scrolled{box-shadow:0 2px 20px rgba(0,0,0,.08)}
.bt-logo-area{flex-shrink:0}
.bt-logo-area img{height:52px;width:auto;transition:height .3s}
.bt-header-center{flex:1;min-width:0;display:flex;align-items:center;justify-content:center}
.bt-header-slogan{font-size:13px;color:var(--bt-text-light);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.bt-header-slogan i{color:var(--bt-accent);margin-right:6px}
.bt-header-right{display:flex;align-items:center;gap:16px;flex-shrink:0}
.bt-header-phone{display:flex;align-items:center;gap:10px;padding:8px 20px;background:linear-gradient(135deg,var(--bt-accent),#d44e08);border-radius:8px;color:#fff;transition:all .3s}
.bt-header-phone:hover{transform:translateY(-1px);box-shadow:0 4px 16px rgba(232,89,12,.35);color:#fff}
.bt-header-phone i{font-size:20px;color:#fff}
.bt-header-phone .num{font-size:20px;font-weight:800;color:#fff;letter-spacing:.5px;display:block;line-height:1.2}
.bt-header-phone .label{font-size:11px;color:rgba(255,255,255,.75);display:block}

/* ====================== HAMBURGER ====================== */
.bt-hamburger{display:none;width:40px;height:40px;flex-direction:column;justify-content:center;align-items:center;gap:5px;cursor:pointer;background:none;border:2px solid var(--bt-border);border-radius:8px;padding:8px;transition:all .3s}
.bt-hamburger span{display:block;width:22px;height:2.5px;background:var(--bt-navy);border-radius:2px;transition:all .3s}
.bt-hamburger.active span:nth-child(1){transform:rotate(45deg) translate(5px,5px)}
.bt-hamburger.active span:nth-child(2){opacity:0}
.bt-hamburger.active span:nth-child(3){transform:rotate(-45deg) translate(5px,-5px)}

/* ====================== NAV ====================== */
.bt-nav{background:var(--bt-primary);position:sticky;top:var(--bt-header-h);z-index:150;height:var(--bt-nav-h)}
.bt-nav-inner{max-width:var(--bt-container-wide);margin:0 auto;padding:0 20px;height:100%}
.bt-nav-list{display:flex;align-items:center;height:100%;justify-content:center}
.bt-nav-list li{flex:1;height:100%}
.bt-nav-link{display:flex;align-items:center;justify-content:center;height:100%;padding:0 12px;color:rgba(255,255,255,.88);font-size:15px;font-weight:500;position:relative;transition:all .2s;letter-spacing:.5px}
.bt-nav-link:hover,.bt-nav-link.active{color:#fff;background:rgba(255,255,255,.1)}
.bt-nav-link.active::after{content:'';position:absolute;bottom:0;left:50%;transform:translateX(-50%);width:32px;height:3px;background:#fff;border-radius:3px 3px 0 0}

/* ====================== MOBILE DRAWER ====================== */
.bt-mobile-overlay{display:none;position:fixed;inset:0;background:rgba(0,0,0,.55);z-index:998;opacity:0;transition:opacity .3s;backdrop-filter:blur(2px)}
.bt-mobile-overlay.show{display:block;opacity:1}
.bt-mobile-drawer{position:fixed;top:0;left:-320px;width:300px;height:100%;background:var(--bt-white);z-index:999;transition:left .35s cubic-bezier(.4,0,.2,1);overflow-y:auto;box-shadow:8px 0 30px rgba(0,0,0,.2)}
.bt-city-switch-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:10px;max-height:calc(100vh - 100px);padding:20px;overflow-y:auto}
.bt-city-switch-item{display:flex;align-items:center;justify-content:center;min-height:42px;padding:8px 10px;border:1px solid var(--bt-border);border-radius:6px;background:#f5f7fa;color:var(--bt-text);font-size:14px;text-align:center;transition:all .2s}
.bt-city-switch-item:hover,.bt-city-switch-item.active{border-color:var(--bt-primary);background:var(--bt-primary);color:#fff}
.bt-city-modal-open{overflow:hidden}
.bt-city-modal{position:fixed;inset:0;z-index:2000;display:flex;align-items:center;justify-content:center;padding:15px;background:rgba(0,0,0,.55)}
.bt-city-modal-dialog{display:flex;flex-direction:column;width:min(600px,100%);max-height:calc(100vh - 30px);overflow:hidden;border-radius:8px;background:#fff;box-shadow:0 20px 60px rgba(0,0,0,.3)}
.bt-city-modal-header{display:flex;align-items:center;justify-content:space-between;min-height:52px;padding:0 18px;border-bottom:1px solid var(--bt-border)}
.bt-city-modal-header h3{margin:0;color:var(--bt-navy);font-size:17px;font-weight:600}
.bt-city-modal-close{display:flex;align-items:center;justify-content:center;width:36px;height:36px;border:0;background:transparent;color:var(--bt-text-light);font-size:18px;cursor:pointer}
.bt-city-modal-close:hover{color:var(--bt-primary)}
.bt-city-modal-body{min-height:0;overflow-y:auto}
.bt-mobile-drawer.open{left:0}
.bt-drawer-header{padding:24px 20px;background:linear-gradient(135deg,var(--bt-primary),var(--bt-primary-dark));display:flex;align-items:center;justify-content:space-between}
.bt-drawer-logo img{height:40px}
.bt-drawer-close{width:32px;height:32px;background:rgba(255,255,255,.15);border:none;border-radius:50%;color:#fff;font-size:18px;cursor:pointer;display:flex;align-items:center;justify-content:center;transition:all .2s}
.bt-drawer-close:hover{background:rgba(255,255,255,.25)}
.bt-drawer-nav{padding:8px 0}
.bt-drawer-nav a{display:flex;align-items:center;gap:14px;padding:15px 24px;font-size:15px;color:var(--bt-text);border-bottom:1px solid var(--bt-border);transition:all .2s}
.bt-drawer-nav a:hover,.bt-drawer-nav a.active{color:var(--bt-primary);background:var(--bt-primary-light);border-left:3px solid var(--bt-primary)}
.bt-drawer-nav a > i:first-child{width:22px;text-align:center;font-size:17px;color:var(--bt-primary)}
.bt-drawer-arrow{margin-left:auto;font-size:16px;color:var(--bt-text-muted)}
.bt-drawer-contact{padding:20px;margin:16px;background:var(--bt-accent-light);border-radius:var(--bt-radius-lg);text-align:center}
.bt-drawer-phone-box{display:flex;align-items:center;gap:12px;justify-content:center;margin-bottom:12px}
.bt-drawer-phone-box i{font-size:24px;color:var(--bt-accent)}
.bt-drawer-phone-box span{font-size:12px;color:var(--bt-text-light);display:block}
.bt-drawer-phone-box strong{font-size:20px;color:var(--bt-accent);font-weight:800}
.bt-drawer-qq{font-size:13px;color:var(--bt-text-light)}

/* ====================== HERO ====================== */
.bt-hero{position:relative;min-height:560px;display:flex;align-items:center;overflow:hidden;color:#fff}
.bt-hero-bg{position:absolute;inset:0;background-size:cover;background-position:center;z-index:0}
.bt-hero-bg::after{content:'';position:absolute;inset:0;background:linear-gradient(135deg,rgba(15,28,46,.9) 0%,rgba(14,79,153,.75) 50%,rgba(26,109,204,.65) 100%)}
.bt-hero .bt-container{position:relative;z-index:1;padding-top:60px;padding-bottom:60px}
.bt-hero-city-tag{display:inline-flex;align-items:center;gap:8px;background:rgba(255,255,255,.1);backdrop-filter:blur(10px);padding:8px 20px;border-radius:24px;color:rgba(255,255,255,.9);font-size:14px;margin-bottom:24px;border:1px solid rgba(255,255,255,.15)}
.bt-hero h1{font-size:46px;font-weight:800;line-height:1.3;margin-bottom:16px;color:#fff}
.bt-hero h1 em{font-style:normal;color:#fbbf24}
.bt-hero p{font-size:17px;color:rgba(255,255,255,.7);line-height:1.9;max-width:560px;margin-bottom:32px}
.bt-hero-card{background:rgba(255,255,255,.07);backdrop-filter:blur(20px);border:1px solid rgba(255,255,255,.1);border-radius:var(--bt-radius-lg);padding:28px;color:#fff}
.bt-hero-card h3{font-size:17px;margin-bottom:18px;font-weight:600;color:#fff;padding-bottom:14px;border-bottom:1px solid rgba(255,255,255,.1)}
.bt-hero-card-item{display:flex;align-items:center;gap:14px;padding:12px 0;border-bottom:1px solid rgba(255,255,255,.06);font-size:14px;color:rgba(255,255,255,.85)}
.bt-hero-card-item:last-child{border-bottom:none}
.bt-hero-card-icon{width:42px;height:42px;border-radius:10px;flex-shrink:0;background:rgba(255,255,255,.08);display:flex;align-items:center;justify-content:center;font-size:18px}
.bt-btn-primary{background:var(--bt-accent);color:#fff;padding:14px 36px;border-radius:8px;font-size:15px;font-weight:600;display:inline-block;transition:all .3s;box-shadow:0 4px 20px rgba(232,89,12,.35);border:none;cursor:pointer;letter-spacing:.5px}
.bt-btn-primary:hover{transform:translateY(-2px);box-shadow:0 8px 30px rgba(232,89,12,.45);color:#fff}
.bt-btn-outline{border:2px solid rgba(255,255,255,.4);color:#fff;padding:12px 30px;border-radius:8px;font-size:15px;font-weight:500;display:inline-block;transition:all .3s;background:transparent;cursor:pointer}
.bt-btn-outline:hover{background:rgba(255,255,255,.12);border-color:rgba(255,255,255,.6);color:#fff}
.bt-btn-outline-dark{border:2px solid var(--bt-primary);color:var(--bt-primary);padding:12px 30px;border-radius:8px;font-size:15px;font-weight:500;display:inline-block;transition:all .3s;background:transparent;cursor:pointer}
.bt-btn-outline-dark:hover{background:var(--bt-primary);color:#fff}

/* ====================== CITY NAV ====================== */
.bt-city-nav{background:var(--bt-white);padding:16px 0;border-bottom:1px solid var(--bt-border)}
.bt-city-nav .bt-container{display:flex;align-items:center;gap:10px;flex-wrap:wrap}
.bt-city-nav-label{font-size:14px;font-weight:600;color:var(--bt-navy);white-space:nowrap;margin-right:4px}
.bt-city-nav a{display:inline-block;padding:6px 16px;border-radius:20px;font-size:13px;color:var(--bt-text-light);border:1px solid var(--bt-border);transition:all .2s}
.bt-city-nav a:hover{border-color:var(--bt-primary);color:var(--bt-primary);background:var(--bt-primary-light)}
.bt-city-nav a.active{background:var(--bt-primary);color:#fff;border-color:var(--bt-primary)}
.bt-city-nav a.more{color:var(--bt-primary);border:1px dashed var(--bt-primary)}

/* ====================== STATS ====================== */
.bt-stats{position:relative;padding:60px 0;overflow:hidden;color:#fff}
.bt-stats-bg{position:absolute;inset:0;background:url('../images/strength-workshop.jpg') center/cover;z-index:0}
.bt-stats-bg::after{content:'';position:absolute;inset:0;background:linear-gradient(135deg,rgba(14,79,153,.92),rgba(26,109,204,.88))}
.bt-stats .bt-container{position:relative;z-index:1}
.bt-stat-item{text-align:center;padding:20px 10px}
.bt-stat-num{font-size:50px;font-weight:800;color:#fff;line-height:1}
.bt-stat-num span{font-size:18px;font-weight:400;color:rgba(255,255,255,.7)}
.bt-stat-label{font-size:14px;color:rgba(255,255,255,.7);margin-top:8px}

/* ====================== SECTIONS ====================== */
.bt-section{padding:80px 0}
.bt-section-sm{padding:50px 0}
.bt-section-white{background:var(--bt-white)}
.bt-section-gray{background:var(--bt-bg)}
.bt-section-dark{background:var(--bt-navy);color:#fff}
.bt-section-img{position:relative;overflow:hidden}
.bt-section-img-bg{position:absolute;inset:0;background-size:cover;background-position:center;z-index:0}
.bt-section-img-bg::after{content:'';position:absolute;inset:0}
.bt-section-img > .bt-container,.bt-section-img > .bt-container-wide{position:relative;z-index:1}

/* section titles */
.bt-section-title{text-align:center;margin-bottom:50px}
.bt-section-title h2{font-size:34px;font-weight:700;color:var(--bt-navy);position:relative;display:inline-block;padding-bottom:16px}
.bt-section-title h2::after{content:'';position:absolute;bottom:0;left:50%;transform:translateX(-50%);width:60px;height:3px;background:var(--bt-primary);border-radius:3px}
.bt-section-title p{font-size:16px;color:var(--bt-text-light);margin-top:12px}
.bt-section-dark .bt-section-title h2{color:#fff}
.bt-section-dark .bt-section-title h2::after{background:#fbbf24}
.bt-section-dark .bt-section-title p{color:rgba(255,255,255,.6)}

/* ====================== PAGE BANNER ====================== */
.bt-page-banner{position:relative;padding:80px 0 60px;color:#fff;overflow:hidden}
.bt-page-banner-bg{position:absolute;inset:0;background-size:cover;background-position:center;z-index:0}
.bt-page-banner-bg::after{content:'';position:absolute;inset:0;background:linear-gradient(135deg,rgba(15,28,46,.92),rgba(14,79,153,.82))}
.bt-page-banner .bt-container{position:relative;z-index:1}
.bt-page-banner h1{font-size:36px;font-weight:800;color:#fff;margin-bottom:10px}
.bt-breadcrumb{font-size:14px;color:rgba(255,255,255,.6)}.bt-breadcrumb a{color:rgba(255,255,255,.8)}.bt-breadcrumb a:hover{color:#fff}

/* ====================== SERVICE CARDS ====================== */
.bt-service-card{background:var(--bt-white);border-radius:var(--bt-radius-lg);padding:36px 28px;text-align:center;box-shadow:var(--bt-shadow);transition:all .35s;border:1px solid var(--bt-border);height:100%}
.bt-service-card:hover{transform:translateY(-8px);box-shadow:var(--bt-shadow-lg);border-color:var(--bt-primary)}
.bt-service-icon{width:72px;height:72px;border-radius:18px;background:var(--bt-primary-light);margin:0 auto 20px;display:flex;align-items:center;justify-content:center;font-size:32px;color:var(--bt-primary);transition:all .3s}
.bt-service-card:hover .bt-service-icon{background:var(--bt-primary);color:#fff}
.bt-service-card h3{font-size:18px;color:var(--bt-navy);margin-bottom:12px;font-weight:600}
.bt-service-card p{font-size:14px;color:var(--bt-text-light);line-height:1.8}
.bt-service-tag{display:inline-block;margin-top:16px;padding:5px 16px;border-radius:14px;background:var(--bt-accent-light);color:var(--bt-accent);font-size:12px;font-weight:600}

/* ====================== PRODUCT CARDS ====================== */
.bt-product-card{background:var(--bt-white);border-radius:var(--bt-radius-lg);overflow:hidden;box-shadow:var(--bt-shadow);transition:all .35s;border:1px solid var(--bt-border);height:100%}
.bt-product-card:hover{transform:translateY(-8px);box-shadow:var(--bt-shadow-lg);border-color:var(--bt-primary)}
.bt-product-img{height:240px;overflow:hidden;position:relative}
.bt-product-img img{width:100%;height:100%;object-fit:cover;transition:transform .5s}
.bt-product-card:hover .bt-product-img img{transform:scale(1.08)}
.bt-product-img .bt-local-tag{position:absolute;top:12px;right:12px;background:var(--bt-accent);color:#fff;padding:4px 14px;border-radius:14px;font-size:11px;font-weight:600;z-index:1}
.bt-product-img .bt-placeholder{width:100%;height:100%;background:linear-gradient(135deg,#e8f0fe,#dbeafe);display:flex;align-items:center;justify-content:center}
.bt-product-img .bt-placeholder i{font-size:52px;color:var(--bt-primary);opacity:.2}
.bt-product-info{padding:22px}
.bt-product-info h3{font-size:17px;color:var(--bt-navy);font-weight:600;margin-bottom:8px}
.bt-product-info p{font-size:14px;color:var(--bt-text-light);line-height:1.7;margin-bottom:0}
.bt-product-info .bt-price-row{display:flex;justify-content:space-between;align-items:center;margin-top:16px;padding-top:16px;border-top:1px solid var(--bt-border)}
.bt-product-info .bt-price{font-size:14px;color:var(--bt-accent);font-weight:600}

/* ====================== CASE CARDS ====================== */
.bt-case-card{border-radius:var(--bt-radius-lg);overflow:hidden;position:relative;height:260px;cursor:pointer}
.bt-case-card img{width:100%;height:100%;object-fit:cover;transition:transform .6s}
.bt-case-card:hover img{transform:scale(1.1)}
.bt-case-card .bt-case-overlay{position:absolute;inset:0;background:linear-gradient(to top,rgba(0,0,0,.85) 0%,rgba(0,0,0,.15) 55%,transparent 100%);display:flex;flex-direction:column;justify-content:flex-end;padding:22px;transition:all .35s}
.bt-case-card:hover .bt-case-overlay{background:linear-gradient(to top,rgba(26,109,204,.92) 0%,rgba(26,109,204,.3) 55%,transparent 100%)}
.bt-case-card h4{font-size:17px;font-weight:600;color:#fff;margin-bottom:6px}
.bt-case-card .bt-case-loc{font-size:12px;color:rgba(255,255,255,.65)}
.bt-case-card .bt-case-placeholder{width:100%;height:100%;background:linear-gradient(135deg,#2c3e50,#1a2332);display:flex;align-items:center;justify-content:center}
.bt-case-card .bt-case-placeholder i{font-size:40px;color:rgba(255,255,255,.12)}

/* ====================== NEWS ====================== */
.bt-news-col h3{font-size:20px;color:var(--bt-navy);font-weight:600;padding-bottom:14px;border-bottom:3px solid var(--bt-primary);margin-bottom:20px;display:flex;justify-content:space-between;align-items:center}
.bt-news-col h3 a{font-size:13px;color:var(--bt-primary);font-weight:400}
.bt-news-item{display:flex;gap:18px;padding:16px 0;border-bottom:1px dashed var(--bt-border)}
.bt-news-date{flex-shrink:0;width:62px;text-align:center;padding:10px 0;background:var(--bt-primary-light);border-radius:var(--bt-radius)}
.bt-news-date .day{font-size:26px;font-weight:700;color:var(--bt-primary);display:block}
.bt-news-date .month{font-size:11px;color:var(--bt-text-light)}
.bt-news-content h4{font-size:15px;color:var(--bt-navy);font-weight:500;line-height:1.5;margin-bottom:6px;cursor:pointer}
.bt-news-content h4:hover{color:var(--bt-primary)}
.bt-news-content p{font-size:13px;color:var(--bt-text-muted)}
.bt-news-content .bt-news-desc{font-size:13px;color:var(--bt-text-light);line-height:1.6;margin-bottom:6px;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}

/* ====================== FAQ ====================== */
.bt-faq-item{background:var(--bt-white);border-radius:var(--bt-radius-lg);padding:26px 30px;margin-bottom:16px;box-shadow:var(--bt-shadow);border-left:4px solid var(--bt-primary);transition:all .3s}
.bt-faq-item:hover{box-shadow:var(--bt-shadow-lg);transform:translateX(4px)}
.bt-faq-item h4{font-size:16px;color:var(--bt-navy);font-weight:600;margin-bottom:10px}
.bt-faq-item p{font-size:14px;color:var(--bt-text-light);line-height:1.9;margin-bottom:0}

/* ====================== CTA (Full-width) ====================== */
.bt-cta{position:relative;padding:70px 0;text-align:center;color:#fff;overflow:hidden}
.bt-cta-bg{position:absolute;inset:0;background:url('../images/strength-workshop.jpg') center/cover;z-index:0}
.bt-cta-bg::after{content:'';position:absolute;inset:0;background:linear-gradient(135deg,rgba(26,109,204,.93),rgba(14,79,153,.96))}
.bt-cta .bt-container{position:relative;z-index:1}
.bt-cta h2{font-size:34px;font-weight:700;margin-bottom:14px;color:#fff}
.bt-cta p{font-size:16px;opacity:.85;margin-bottom:30px;color:rgba(255,255,255,.85)}
.bt-cta-phone{display:inline-flex;align-items:center;gap:10px;background:#fff;color:var(--bt-primary);padding:16px 40px;border-radius:8px;font-size:20px;font-weight:700;transition:all .3s}
.bt-cta-phone:hover{transform:translateY(-3px);box-shadow:0 10px 30px rgba(0,0,0,.2);color:var(--bt-primary-dark)}
.bt-cta-consult{display:inline-flex;align-items:center;gap:10px;border:2px solid rgba(255,255,255,.5);color:#fff;padding:14px 32px;border-radius:8px;font-size:16px;font-weight:500;transition:all .3s;background:transparent;margin-left:12px}
.bt-cta-consult:hover{background:rgba(255,255,255,.12);color:#fff;border-color:rgba(255,255,255,.7)}

/* ====================== FOOTER ====================== */
.bt-footer{background:var(--bt-navy);color:rgba(255,255,255,.6);padding-top:0}
.bt-footer-main{max-width:var(--bt-container-wide);margin:0 auto;padding:50px 20px 30px}
.bt-footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr 1.5fr;gap:40px}
.bt-footer h4{font-size:17px;color:#fff;font-weight:600;margin-bottom:20px;padding-bottom:12px;border-bottom:2px solid var(--bt-primary);display:inline-block}
.bt-footer p{font-size:14px;line-height:1.9;color:rgba(255,255,255,.55)}
.bt-footer-contact-line{font-size:13px;color:rgba(255,255,255,.5);padding:3px 0}
.bt-footer-contact-line i{width:18px;color:var(--bt-primary);margin-right:4px}
.bt-footer-col a{color:rgba(255,255,255,.5);display:block;padding:4px 0;font-size:14px;transition:all .2s}
.bt-footer-col a:hover{color:#fff;transform:translateX(4px)}
.bt-footer-city-tags{display:flex;flex-wrap:wrap;gap:6px;margin-top:12px}
.bt-footer-city-tags a{display:inline-block;padding:5px 14px;background:rgba(255,255,255,.05);border-radius:14px;font-size:12px;color:rgba(255,255,255,.4);border:1px solid rgba(255,255,255,.06)}
.bt-footer-city-tags a:hover{background:rgba(26,109,204,.25);color:#7db8f5;border-color:rgba(26,109,204,.3)}
.bt-footer-bottom{border-top:1px solid rgba(255,255,255,.06);padding:18px 20px;text-align:center;font-size:13px;color:rgba(255,255,255,.3)}

/* ====================== FLOAT SIDEBAR ====================== */
.bt-float-sidebar{position:fixed;right:16px;top:50%;transform:translateY(-50%);z-index:120;display:flex;flex-direction:column;gap:2px}
.bt-float-btn{width:52px;height:52px;display:flex;flex-direction:column;align-items:center;justify-content:center;background:var(--bt-primary);color:#fff;font-size:10px;gap:3px;cursor:pointer;transition:all .2s;text-decoration:none}
.bt-float-btn:first-child{border-radius:10px 10px 0 0}.bt-float-btn:last-child{border-radius:0 0 10px 10px}
.bt-float-btn:hover{background:var(--bt-primary-dark);color:#fff}
.bt-float-btn i{font-size:18px}.bt-float-btn.accent{background:var(--bt-accent)}.bt-float-btn.accent:hover{background:var(--bt-accent-dark)}

/* ====================== DETAIL PAGES ====================== */
.bt-detail-sidebar{background:var(--bt-white);border-radius:var(--bt-radius-lg);box-shadow:var(--bt-shadow);padding:28px;position:sticky;top:160px}
.bt-detail-sidebar h4{font-size:17px;color:var(--bt-navy);font-weight:600;padding-bottom:14px;border-bottom:2px solid var(--bt-primary);margin-bottom:14px}
.bt-detail-sidebar .list-group-item{border:none;padding:12px 16px;border-radius:var(--bt-radius);margin-bottom:4px;font-size:14px;color:var(--bt-text);transition:all .2s}
.bt-detail-sidebar .list-group-item:hover,.bt-detail-sidebar .list-group-item.active{background:var(--bt-primary-light);color:var(--bt-primary);font-weight:600}
.bt-detail-content{background:var(--bt-white);border-radius:var(--bt-radius-lg);box-shadow:var(--bt-shadow);padding:40px}
.bt-detail-content h2{font-size:26px;margin-bottom:10px}
.bt-detail-meta{font-size:13px;color:var(--bt-text-light);margin-bottom:28px;padding-bottom:18px;border-bottom:1px solid var(--bt-border)}
.bt-detail-body{font-size:15px;line-height:2;color:var(--bt-text)}
.bt-detail-body h3{font-size:20px;margin:32px 0 16px;padding-left:14px;border-left:4px solid var(--bt-primary)}
.bt-detail-body img{border-radius:var(--bt-radius);margin:16px 0}
.bt-prenext{display:flex;flex-direction:column;gap:10px;margin-top:30px;padding-top:20px;border-top:1px solid var(--bt-border);font-size:14px}
.bt-prenext-item{color:var(--bt-text-light);line-height:1.7}
.bt-prenext-item strong{color:var(--bt-navy)}
.bt-prenext-item a{color:var(--bt-text);transition:color .2s}
.bt-prenext-item a:hover{color:var(--bt-primary)}
.bt-block-title{font-size:20px;margin:30px 0 20px;padding-left:12px;border-left:4px solid var(--bt-primary);color:var(--bt-navy)}
.bt-news-card{background:var(--bt-white);padding:18px;border-radius:var(--bt-radius);box-shadow:var(--bt-shadow);border:1px solid var(--bt-border);transition:all .3s;height:100%}
.bt-news-card:hover{transform:translateY(-4px);box-shadow:var(--bt-shadow-lg);border-color:var(--bt-primary)}
.bt-news-card h4{font-size:15px;line-height:1.6;margin-bottom:8px}
.bt-news-card h4 a{color:var(--bt-navy)}
.bt-news-card p{font-size:13px;color:var(--bt-text-light);margin-bottom:0}

/* ====================== ABOUT ====================== */
.bt-about-feature{text-align:center;padding:28px 20px;background:var(--bt-white);border-radius:var(--bt-radius-lg);box-shadow:var(--bt-shadow);transition:all .3s;border:1px solid var(--bt-border);height:100%}
.bt-about-feature:hover{transform:translateY(-6px);box-shadow:var(--bt-shadow-lg);border-color:var(--bt-primary)}
.bt-about-feature img{width:100%;height:160px;object-fit:cover;border-radius:var(--bt-radius);margin-bottom:16px}
.bt-about-feature i{font-size:40px;color:var(--bt-primary);margin-bottom:16px}
.bt-about-feature h4{font-size:16px;color:var(--bt-navy);font-weight:600;margin-bottom:6px}
.bt-about-feature p{font-size:13px;color:var(--bt-text-light);margin-bottom:0}
.bt-team-features{display:grid;grid-template-columns:1fr 1fr;gap:14px}
.bt-team-feature{display:flex;align-items:center;gap:12px;padding:14px 18px;background:var(--bt-primary-light);border-radius:var(--bt-radius);font-size:14px;color:var(--bt-navy)}
.bt-team-feature i{font-size:22px;color:var(--bt-primary)}

/* ====================== PROCESS ====================== */
.bt-process-step{text-align:center;position:relative;padding:24px}
.bt-process-num{width:64px;height:64px;border-radius:50%;background:var(--bt-primary);color:#fff;display:flex;align-items:center;justify-content:center;font-size:24px;font-weight:700;margin:0 auto 18px;transition:all .3s;box-shadow:0 4px 16px rgba(26,109,204,.3)}
.bt-process-step:hover .bt-process-num{background:var(--bt-accent);transform:scale(1.12);box-shadow:0 6px 20px rgba(232,89,12,.3)}
.bt-process-step h4{font-size:16px;color:var(--bt-navy);font-weight:600;margin-bottom:8px}
.bt-process-step p{font-size:13px;color:var(--bt-text-light);margin-bottom:0}
.bt-process-arrow{position:absolute;right:-14px;top:40px;font-size:18px;color:var(--bt-primary);z-index:1}
.bt-process-row>div:last-child .bt-process-arrow{display:none}

/* ====================== CONTACT ====================== */
.bt-contact-info{background:var(--bt-white);border-radius:var(--bt-radius-lg);padding:36px;box-shadow:var(--bt-shadow);height:100%;border:1px solid var(--bt-border)}
.bt-contact-item{display:flex;gap:18px;padding:18px 0;border-bottom:1px solid var(--bt-border)}
.bt-contact-item:last-child{border-bottom:none}
.bt-contact-icon{width:52px;height:52px;border-radius:14px;flex-shrink:0;background:var(--bt-primary-light);display:flex;align-items:center;justify-content:center;font-size:22px;color:var(--bt-primary)}
.bt-contact-text h4{font-size:16px;color:var(--bt-navy);font-weight:600;margin-bottom:4px}
.bt-contact-text p{font-size:14px;color:var(--bt-text-light);margin-bottom:0}

/* ====================== CONSULT FORM ====================== */
.bt-form-card{background:var(--bt-white);border-radius:var(--bt-radius-lg);box-shadow:var(--bt-shadow-lg);padding:44px 48px;max-width:780px;margin:0 auto;border:1px solid var(--bt-border)}
.bt-form-grid{display:grid;grid-template-columns:1fr 1fr;gap:22px 26px}
.bt-form-field{display:flex;flex-direction:column}
.bt-form-field.full{grid-column:1/-1}
.bt-form-label{font-size:14px;font-weight:600;color:var(--bt-navy);margin-bottom:8px}
.bt-form-label .req{color:var(--bt-accent);margin-left:3px}
.bt-form-control{width:100%;height:46px;padding:0 16px;border:1.5px solid var(--bt-border);border-radius:var(--bt-radius);font-size:14px;color:var(--bt-text);background:var(--bt-white);transition:border-color .25s,box-shadow .25s;outline:none;font-family:inherit;line-height:1.5}
.bt-form-control::placeholder{color:var(--bt-text-muted)}
.bt-form-control:hover{border-color:#c3d5ec}
.bt-form-control:focus{border-color:var(--bt-primary);box-shadow:0 0 0 3px rgba(26,109,204,.12)}
textarea.bt-form-control{height:auto;min-height:120px;padding:12px 16px;resize:vertical;line-height:1.6}
select.bt-form-control{appearance:none;-webkit-appearance:none;-moz-appearance:none;background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath fill='%23777' d='M6 8L0 0h12z'/%3E%3C/svg%3E");background-repeat:no-repeat;background-position:right 16px center;padding-right:42px;cursor:pointer}
select.bt-form-control option[value=""]{color:var(--bt-text-muted)}
.bt-region-wrap{display:flex;flex-direction:column;gap:10px}
.bt-form-actions{text-align:center;margin-top:30px}
.bt-form-submit{display:inline-flex;align-items:center;justify-content:center;gap:10px;min-width:220px;height:50px;padding:0 36px;border:none;border-radius:var(--bt-radius);background:linear-gradient(135deg,var(--bt-accent),#d44e08);color:#fff;font-size:17px;font-weight:600;letter-spacing:1px;cursor:pointer;transition:all .3s;font-family:inherit}
.bt-form-submit:hover{transform:translateY(-2px);box-shadow:0 8px 24px rgba(232,89,12,.35)}
.bt-form-submit i{font-size:16px}
.bt-form-tip{font-size:13px;color:var(--bt-text-muted);margin-top:14px}

/* ====================== CATEGORY TABS ====================== */
.bt-category-tabs{background:var(--bt-white);border-radius:var(--bt-radius-lg);padding:18px 28px;box-shadow:var(--bt-shadow);margin-bottom:32px;border:1px solid var(--bt-border)}
.bt-category-tabs .nav-link{color:var(--bt-text-light);padding:10px 22px;border-radius:6px;font-size:14px;font-weight:500;transition:all .2s}
.bt-category-tabs .nav-link:hover{color:var(--bt-primary);background:var(--bt-primary-light)}
.bt-category-tabs .nav-link.active{background:var(--bt-primary);color:#fff}

/* ====================== PAGINATION ====================== */
.bt-pagination .page-link{color:var(--bt-primary);border-color:var(--bt-border);border-radius:6px;margin:0 3px;padding:8px 16px}
.bt-pagination .page-item.active .page-link{background:var(--bt-primary);border-color:var(--bt-primary)}

/* ====================== TIMELINE SWIPER ====================== */
.bt-swiper-timeline{overflow:visible;position:relative;padding-bottom:10px}
.bt-swiper-timeline .swiper-slide{height:auto;padding-top:20px}
.bt-swiper-timeline .swiper-slide::before{content:'';position:absolute;top:38px;left:0;right:0;height:3px;background:linear-gradient(90deg,var(--bt-primary),var(--bt-primary-dark));z-index:0}
.bt-swiper-timeline .swiper-button-next,.bt-swiper-timeline .swiper-button-prev{width:36px;height:36px;border-radius:50%;background:var(--bt-white);box-shadow:0 2px 12px rgba(0,0,0,.1)}
.bt-swiper-timeline .swiper-button-next::after,.bt-swiper-timeline .swiper-button-prev::after{font-size:13px;color:var(--bt-primary);font-weight:700}
.bt-swiper-timeline .swiper-button-next{right:-18px}.bt-swiper-timeline .swiper-button-prev{left:-18px}
.bt-timeline-h-dot{width:16px;height:16px;border-radius:50%;background:var(--bt-primary);border:3px solid var(--bt-white);box-shadow:0 0 0 3px var(--bt-primary);margin:30px auto 14px;position:relative;z-index:1}
.bt-timeline-h-year{font-size:18px;font-weight:800;color:var(--bt-accent);margin-bottom:8px;text-align:center}
.bt-timeline-h-card{background:var(--bt-white);border-radius:var(--bt-radius);padding:16px 12px;box-shadow:var(--bt-shadow);border:1px solid var(--bt-border);transition:all .3s;min-height:100px}
.bt-timeline-h-card:hover{transform:translateY(-4px);box-shadow:var(--bt-shadow-lg);border-color:var(--bt-primary)}
.bt-timeline-h-card h4{font-size:15px;color:var(--bt-navy);font-weight:600;margin-bottom:6px}
.bt-timeline-h-card p{font-size:12px;color:var(--bt-text-light);line-height:1.6;margin-bottom:0}

/* ====================== WOW STAGGER DELAYS ====================== */
.bt-service-card.wow,.bt-product-card.wow,.bt-about-feature.wow,.bt-case-card.wow,.bt-faq-item.wow,.bt-process-step.wow,.bt-contact-item.wow{visibility:hidden}
.row>.col-lg-3:nth-child(2)>.wow,.row>.col-lg-4:nth-child(2)>.wow,.row>.col-md-6:nth-child(2)>.wow,.bt-faq-grid>.bt-faq-item:nth-child(2),.row>.col-lg-2:nth-child(2)>.wow{animation-delay:.1s}
.row>.col-lg-3:nth-child(3)>.wow,.row>.col-lg-4:nth-child(3)>.wow,.row>.col-md-6:nth-child(3)>.wow,.bt-faq-grid>.bt-faq-item:nth-child(3),.row>.col-lg-2:nth-child(3)>.wow{animation-delay:.2s}
.row>.col-lg-3:nth-child(4)>.wow,.row>.col-lg-4:nth-child(4)>.wow,.row>.col-md-6:nth-child(4)>.wow,.bt-faq-grid>.bt-faq-item:nth-child(4),.row>.col-lg-2:nth-child(4)>.wow{animation-delay:.3s}
.row>.col-lg-3:nth-child(5)>.wow,.row>.col-lg-4:nth-child(5)>.wow,.row>.col-md-6:nth-child(5)>.wow,.row>.col-lg-2:nth-child(5)>.wow{animation-delay:.4s}
.row>.col-lg-3:nth-child(6)>.wow,.row>.col-lg-4:nth-child(6)>.wow,.row>.col-md-6:nth-child(6)>.wow,.row>.col-lg-2:nth-child(6)>.wow{animation-delay:.5s}

/* ====================== SWIPER CUSTOM ====================== */
.bt-swiper-case .swiper-slide{height:auto}
.bt-swiper-case .swiper-button-next,.bt-swiper-case .swiper-button-prev{width:44px;height:44px;border-radius:50%;box-shadow:0 2px 12px rgba(0,0,0,.1)}
.bt-swiper-case .swiper-button-next::after,.bt-swiper-case .swiper-button-prev::after{font-size:15px;color:var(--bt-primary);font-weight:700}

/* ====================== FULL-WIDTH FEATURE SECTIONS ====================== */
.bt-fullwidth-img{position:relative;padding:80px 0;overflow:hidden}
.bt-fullwidth-img-bg{position:absolute;inset:0;background-size:cover;background-position:center}
.bt-fullwidth-img-bg::after{content:'';position:absolute;inset:0;background:rgba(0,0,0,.45)}
.bt-fullwidth-img .bt-container{position:relative;z-index:1;color:#fff}

/* split layout: image left/right + content */
.bt-split{display:flex;align-items:stretch;min-height:480px}
.bt-split-img{flex:1;min-height:400px;background-size:cover;background-position:center}
.bt-split-content{flex:1;display:flex;align-items:center;padding:60px 80px}
.bt-split-content-inner{max-width:480px}

/* ====================== RESPONSIVE — TABLET ====================== */
@media(max-width:1199px){
  .bt-footer-grid{grid-template-columns:1.5fr 1fr 1fr 1.5fr;gap:30px}
  .bt-hero h1{font-size:38px}
  .bt-nav-link{padding:0 20px;font-size:14px}
}
@media(max-width:991px){
  .bt-hero{min-height:auto}
  .bt-hero h1{font-size:30px}
  .bt-stat-num{font-size:38px}
  .bt-float-sidebar{display:none}
  .bt-hamburger{display:flex}
  .bt-nav{display:none!important}
  .bt-topbar{display:none}
  .bt-header{top:0;height:60px;min-height:60px}
  .bt-header-inner{height:60px}
  .bt-logo-area,.bt-logo-area a,.bt-header-right{height:100%;display:flex;align-items:center}
  .bt-header-scrolled{top:0}
  .bt-header-phone{display:none}
  .bt-header-slogan{display:none}
  .bt-section{padding:50px 0}
  .bt-section-title h2{font-size:26px}
  .bt-page-banner{padding:50px 0 40px}
  .bt-page-banner h1{font-size:26px}
  .bt-process-arrow{display:none}
  .bt-footer-grid{grid-template-columns:1fr 1fr;gap:24px}
  .bt-split{flex-direction:column}
  .bt-split-content{padding:40px 20px}
  .bt-cta h2{font-size:26px}
  .bt-cta-phone{font-size:18px;padding:14px 30px}
  .bt-cta-consult{margin-left:0;margin-top:12px}
}

/* ====================== RESPONSIVE — MOBILE ====================== */
@media(max-width:767px){
  .bt-city-switch-grid{grid-template-columns:repeat(3,minmax(0,1fr));gap:8px;padding:15px}
  .bt-hero .bt-container{padding-top:36px;padding-bottom:36px}
  .bt-hero h1{font-size:24px}
  .bt-hero p{font-size:14px}
  .bt-section{padding:40px 0}
  .bt-section-title{margin-bottom:30px}
  .bt-section-title h2{font-size:22px}
  .bt-logo-area img{height:38px}
  .bt-header-phone .num{font-size:14px}
  .bt-page-banner{padding:30px 0}
  .bt-page-banner h1{font-size:22px}
  .bt-city-nav .bt-container{gap:6px}
  .bt-city-nav a{padding:4px 10px;font-size:12px}
  .bt-case-card{height:200px}
  .bt-product-img{height:200px}
  .bt-cta{padding:50px 0}
  .bt-cta h2{font-size:22px}
  .bt-cta p{font-size:14px}
  .bt-cta-phone{font-size:16px;padding:12px 24px}
  .bt-stats{padding:36px 0}
  .bt-stat-num{font-size:30px}
  .bt-stat-label{font-size:12px}
  .bt-detail-sidebar{position:static;margin-bottom:20px}
  .bt-team-features{grid-template-columns:1fr}
  .bt-hero-card{margin-top:24px}
  .bt-footer-grid{grid-template-columns:1fr;gap:20px}
  .bt-footer-main{padding:30px 20px 20px}
  .bt-detail-content{padding:24px}
  .bt-swiper-timeline .swiper-button-next,.bt-swiper-timeline .swiper-button-prev{display:none}
  .bt-form-card{padding:28px 22px}
  .bt-form-grid{grid-template-columns:1fr;gap:18px}
  .bt-form-submit{width:100%}
}