@charset "utf-8";
/* 淮南明科网络科技有限公司 — 首页改版 V2.0 */

:root {
  --bt-primary: #0A2463;
  --bt-secondary: #1565C0;
  --bt-accent: #FF6B35;
  --bt-accent-hover: #e85a28;
  --bt-bg: #F8FAFF;
  --bt-dark: #0A1628;
  --bt-text: #1A1A2E;
  --bt-muted: #6B7280;
  --bt-white: #fff;
  --bt-border: rgba(10, 36, 99, 0.08);
  --bt-radius: 12px;
  --bt-radius-lg: 20px;
  --bt-shadow: 0 4px 24px rgba(10, 36, 99, 0.08);
  --bt-shadow-hover: 0 12px 40px rgba(10, 36, 99, 0.16);
  --bt-transition: 0.3s ease;
  --bt-font: 'Noto Sans SC', 'Inter', system-ui, sans-serif;
  --bt-header-h: 72px;
}

/* ── keep sections only：不覆盖原站 header/footer/banner ── */
body.bt-site.bt-noscroll { overflow: hidden; }
.bt-story-quote { font-size: 16px; line-height: 1.85; color: var(--bt-text); border-left: 3px solid var(--bt-accent); padding-left: 16px; margin: 12px 0 0; font-weight: 600; }
.bt-cases-more { text-align: center; margin-top: 40px; }
body.bt-site a { color: inherit; text-decoration: none; transition: color var(--bt-transition); }
body.bt-site img { max-width: 100%; height: auto; display: block; }
body.bt-site ul, body.bt-site ol { margin: 0; padding: 0; list-style: none; }

/* ── Global ── */
.bt-container { width: 100%; max-width: 1200px; margin: 0 auto; padding: 0 24px; box-sizing: border-box; }
.bt-section { padding: 96px 0; }
.bt-section-head { text-align: center; margin-bottom: 56px; }
.bt-title { margin: 0 0 12px; font-size: clamp(28px, 4vw, 38px); font-weight: 700; line-height: 1.3; color: var(--bt-text); letter-spacing: -0.02em; }
.bt-sub { margin: 0 auto; max-width: 640px; font-size: 16px; line-height: 1.75; color: var(--bt-muted); }
.bt-eyebrow { display: inline-block; margin-bottom: 14px; padding: 6px 16px; border-radius: 999px; background: rgba(21, 101, 192, 0.08); color: var(--bt-secondary); font-size: 12px; font-weight: 700; letter-spacing: 0.12em; text-transform: uppercase; }

.bt-btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; padding: 14px 28px; border-radius: 8px; font: 600 15px/1 var(--bt-font); cursor: pointer; border: 2px solid transparent; transition: all var(--bt-transition); white-space: nowrap; }
.bt-btn-primary { background: var(--bt-accent); color: var(--bt-white); border-color: var(--bt-accent); box-shadow: 0 4px 16px rgba(255, 107, 53, 0.35); }
.bt-btn-primary:hover { background: var(--bt-accent-hover); border-color: var(--bt-accent-hover); transform: translateY(-2px); box-shadow: 0 8px 24px rgba(255, 107, 53, 0.45); color: var(--bt-white); }
.bt-btn-outline { background: transparent; color: var(--bt-white); border-color: rgba(255, 255, 255, 0.6); }
.bt-btn-outline:hover { background: rgba(255, 255, 255, 0.12); border-color: var(--bt-white); transform: translateY(-2px); color: var(--bt-white); }
.bt-btn-outline-dark { background: transparent; color: var(--bt-primary); border-color: var(--bt-primary); }
.bt-btn-outline-dark:hover { background: var(--bt-primary); color: var(--bt-white); transform: translateY(-2px); }

/* shared card lift */
.bt-svc-card, .bt-case-card, .bt-why-card, .bt-story-card, .bt-news-card { transition: all var(--bt-transition); }
.bt-svc-card:hover, .bt-case-card:hover, .bt-why-card:hover, .bt-story-card:hover, .bt-news-card:hover { transform: translateY(-4px); box-shadow: var(--bt-shadow-hover); }

/* ── Header ── */
.bt-header { position: fixed; top: 0; left: 0; right: 0; z-index: 1000; height: var(--bt-header-h); transition: background var(--bt-transition), box-shadow var(--bt-transition), backdrop-filter var(--bt-transition); }
.bt-header .bt-container { display: flex; align-items: center; justify-content: space-between; height: 100%; gap: 24px; }
.bt-header .bt-logo { flex-shrink: 0; }
.bt-header .bt-logo a { display: block; }
.bt-header .bt-logo img { height: 44px; width: auto; transition: filter var(--bt-transition); }
.bt-nav { display: flex; align-items: center; gap: 8px; flex: 1; justify-content: center; }
.bt-nav a { display: block; padding: 8px 10px; font-size: 14px; font-weight: 500; color: rgba(255, 255, 255, 0.88); border-radius: 6px; transition: all var(--bt-transition); }
.bt-nav a:hover, .bt-nav a.is-active { color: var(--bt-white); background: rgba(255, 255, 255, 0.1); }
.bt-header-actions { display: flex; align-items: center; gap: 16px; flex-shrink: 0; }
.bt-header-phone { display: flex; align-items: center; gap: 8px; font-size: 14px; font-weight: 600; color: rgba(255, 255, 255, 0.9); white-space: nowrap; }
.bt-header-actions .bt-btn-primary { padding: 10px 20px; font-size: 14px; }

.bt-header.is-scrolled { background: rgba(255, 255, 255, 0.95); backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px); box-shadow: 0 1px 0 var(--bt-border), 0 4px 24px rgba(10, 36, 99, 0.06); }
.bt-header.is-scrolled .bt-nav a { color: var(--bt-text); }
.bt-header.is-scrolled .bt-nav a:hover, .bt-header.is-scrolled .bt-nav a.is-active { color: var(--bt-secondary); background: rgba(21, 101, 192, 0.06); }
.bt-header.is-scrolled .bt-header-phone { color: var(--bt-text); }

.bt-burger { display: none; flex-direction: column; justify-content: center; gap: 5px; width: 40px; height: 40px; padding: 8px; background: none; border: none; cursor: pointer; z-index: 1002; }
.bt-burger span { display: block; width: 100%; height: 2px; background: var(--bt-white); border-radius: 2px; transition: all var(--bt-transition); }
.bt-header.is-scrolled .bt-burger span { background: var(--bt-primary); }
.bt-burger.is-open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.bt-burger.is-open span:nth-child(2) { opacity: 0; }
.bt-burger.is-open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

.bt-mnav { position: fixed; inset: 0; z-index: 1001; background: var(--bt-dark); display: flex; flex-direction: column; align-items: center; justify-content: center; opacity: 0; visibility: hidden; transition: all var(--bt-transition); }
.bt-mnav.is-open { opacity: 1; visibility: visible; }
.bt-mnav ul { text-align: center; }
.bt-mnav li { margin: 8px 0; }
.bt-mnav a { display: block; padding: 14px 24px; font-size: 20px; font-weight: 500; color: rgba(255, 255, 255, 0.85); transition: color var(--bt-transition); }
.bt-mnav a:hover { color: var(--bt-accent); }
.bt-mnav .bt-header-phone { margin-top: 32px; font-size: 18px; color: var(--bt-white); }
.bt-mnav .bt-btn-primary { margin-top: 16px; }

/* ── Hero ── */
.bt-hero { position: relative; min-height: 100vh; min-height: 100dvh; display: flex; align-items: center; padding: calc(var(--bt-header-h) + 48px) 0 120px; background: linear-gradient(135deg, var(--bt-primary) 0%, var(--bt-secondary) 100%); overflow: hidden; color: var(--bt-white); }
.bt-hero::before { content: ''; position: absolute; inset: 0; background-image: repeating-linear-gradient(0deg, rgba(255,255,255,.04) 0 1px, transparent 1px 60px), repeating-linear-gradient(90deg, rgba(255,255,255,.04) 0 1px, transparent 1px 60px); pointer-events: none; }
.bt-hero::after { content: ''; position: absolute; top: -30%; right: -10%; width: 60%; height: 80%; background: radial-gradient(ellipse, rgba(255,107,53,.15) 0%, transparent 70%); pointer-events: none; }
.bt-hero .bt-container { position: relative; z-index: 1; display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: center; }
.bt-hero-copy h1 { margin: 0 0 20px; font-size: clamp(32px, 5vw, 52px); font-weight: 800; line-height: 1.15; letter-spacing: -0.03em; }
.bt-hero-copy h1 em { font-style: normal; color: var(--bt-accent); }
.bt-hero-copy p { margin: 0 0 32px; font-size: 18px; line-height: 1.75; color: rgba(255,255,255,.82); max-width: 520px; }
.bt-hero-btns { display: flex; flex-wrap: wrap; gap: 16px; }

.bt-hero-slider { position: relative; border-radius: var(--bt-radius-lg); overflow: hidden; box-shadow: 0 24px 64px rgba(0,0,0,.3); aspect-ratio: 16/11; }
.bt-hero-slider .swiper-slide img { width: 100%; height: 100%; object-fit: cover; }
.bt-hero-slider .swiper-pagination-bullet { background: var(--bt-white); opacity: .4; }
.bt-hero-slider .swiper-pagination-bullet-active { opacity: 1; background: var(--bt-accent); }

.bt-trust { position: absolute; bottom: 0; left: 0; right: 0; z-index: 2; background: rgba(10,22,40,.6); backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px); border-top: 1px solid rgba(255,255,255,.08); }
.bt-trust .bt-container { display: flex; align-items: center; justify-content: center; gap: 48px; padding: 20px 24px; }
.bt-trust-item { display: flex; align-items: center; gap: 10px; font-size: 14px; font-weight: 500; color: rgba(255,255,255,.9); }
.bt-trust-item::before { content: '✓'; display: flex; align-items: center; justify-content: center; width: 22px; height: 22px; border-radius: 50%; background: var(--bt-accent); font-size: 11px; font-weight: 700; flex-shrink: 0; }

/* ── Stats ── */
.bt-stats { position: relative; background: var(--bt-dark); color: var(--bt-white); padding: 128px 0 80px; clip-path: polygon(0 48px, 100% 0, 100% 100%, 0 100%); }
.bt-stats-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 32px; text-align: center; }
.bt-stat-num { display: block; font-size: clamp(36px, 5vw, 56px); font-weight: 800; line-height: 1; color: var(--bt-accent); margin-bottom: 8px; letter-spacing: -0.02em; }
.bt-stat-num sup, .bt-stat-num span { font-size: .5em; font-weight: 600; }
.bt-stat-label { font-size: 15px; color: rgba(255,255,255,.65); line-height: 1.5; }

/* ── Services ── */
.bt-svc { background: var(--bt-bg); }
.bt-tabs { display: flex; justify-content: center; gap: 8px; margin-bottom: 48px; flex-wrap: wrap; border-bottom: 1px solid var(--bt-border); }
.bt-tab { position: relative; padding: 14px 24px; font: 600 15px var(--bt-font); color: var(--bt-muted); background: none; border: none; cursor: pointer; transition: color var(--bt-transition); }
.bt-tab::after { content: ''; position: absolute; bottom: -1px; left: 50%; transform: translateX(-50%) scaleX(0); width: 100%; height: 3px; background: var(--bt-accent); border-radius: 3px 3px 0 0; transition: transform var(--bt-transition); }
.bt-tab:hover { color: var(--bt-text); }
.bt-tab.is-active { color: var(--bt-accent); }
.bt-tab.is-active::after { transform: translateX(-50%) scaleX(1); }
.bt-tab-panel { display: none; animation: btFadeIn .4s ease; }
.bt-tab-panel.is-active { display: block; }
@keyframes btFadeIn { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: translateY(0); } }

.bt-svc-cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.bt-svc-card { background: var(--bt-white); border: 1px solid var(--bt-border); border-radius: var(--bt-radius); padding: 32px 28px; box-shadow: var(--bt-shadow); }
.bt-svc-card:hover { border-color: rgba(21,101,192,.15); }
.bt-svc-card-icon { width: 52px; height: 52px; border-radius: 14px; background: linear-gradient(135deg, rgba(21,101,192,.1), rgba(10,36,99,.06)); display: flex; align-items: center; justify-content: center; margin-bottom: 20px; color: var(--bt-secondary); font-size: 24px; }
.bt-svc-card h3 { margin: 0 0 10px; font-size: 18px; font-weight: 700; color: var(--bt-text); }
.bt-svc-card p { margin: 0 0 16px; font-size: 14px; line-height: 1.7; color: var(--bt-muted); }
.bt-svc-card a { font-size: 14px; font-weight: 600; color: var(--bt-secondary); }
.bt-svc-card a:hover { color: var(--bt-accent); }

/* ── Process ── */
.bt-process { background: var(--bt-white); }
.bt-process-steps { display: flex; align-items: flex-start; justify-content: space-between; }
.bt-process-step { flex: 1; text-align: center; position: relative; padding: 0 12px; }
.bt-process-step::after { content: ''; position: absolute; top: 28px; left: calc(50% + 28px); width: calc(100% - 56px); border-top: 2px dashed rgba(21,101,192,.25); }
.bt-process-step:last-child::after { display: none; }
.bt-process-num { display: flex; align-items: center; justify-content: center; width: 56px; height: 56px; margin: 0 auto 16px; border-radius: 50%; background: linear-gradient(135deg, var(--bt-primary), var(--bt-secondary)); color: var(--bt-white); font-size: 18px; font-weight: 700; box-shadow: 0 4px 16px rgba(10,36,99,.2); position: relative; z-index: 1; }
.bt-process-step h4 { margin: 0 0 6px; font-size: 15px; font-weight: 700; color: var(--bt-text); }
.bt-process-step p { margin: 0; font-size: 13px; color: var(--bt-muted); line-height: 1.5; }

/* ── Cases ── */
.bt-cases { background: var(--bt-bg); }
.bt-filter { display: flex; flex-wrap: wrap; justify-content: center; gap: 10px; margin-bottom: 40px; }
.bt-filter-btn, .bt-filter button { padding: 8px 20px; border-radius: 999px; font: 500 14px var(--bt-font); color: var(--bt-muted); background: var(--bt-white); border: 1px solid var(--bt-border); cursor: pointer; transition: all var(--bt-transition); }
.bt-filter-btn:hover, .bt-filter-btn.is-active, .bt-filter button:hover, .bt-filter button.is-active { background: var(--bt-primary); border-color: var(--bt-primary); color: var(--bt-white); }
.bt-cases-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.bt-case-card { position: relative; border-radius: var(--bt-radius); overflow: hidden; background: var(--bt-white); box-shadow: var(--bt-shadow); }
.bt-case-card-img { position: relative; aspect-ratio: 16/10; overflow: hidden; }
.bt-case-card-img img { width: 100%; height: 100%; object-fit: cover; transition: transform .5s ease; }
.bt-case-card:hover .bt-case-card-img img { transform: scale(1.05); }
.bt-case-card-overlay { position: absolute; inset: 0; background: linear-gradient(to top, rgba(10,36,99,.85) 0%, transparent 60%); display: flex; align-items: flex-end; justify-content: center; padding: 24px; opacity: 0; transition: opacity var(--bt-transition); }
.bt-case-card:hover .bt-case-card-overlay { opacity: 1; }
.bt-case-card-overlay a { padding: 10px 24px; background: var(--bt-accent); color: var(--bt-white); border-radius: 6px; font-size: 14px; font-weight: 600; transform: translateY(12px); transition: all var(--bt-transition); }
.bt-case-card:hover .bt-case-card-overlay a { transform: translateY(0); }
.bt-case-card-body { padding: 20px 24px; }
.bt-case-card-tag { display: inline-block; margin-bottom: 8px; padding: 3px 10px; border-radius: 4px; background: rgba(21,101,192,.08); color: var(--bt-secondary); font-size: 12px; font-weight: 600; }
.bt-case-card-body h3 { margin: 0 0 6px; font-size: 17px; font-weight: 700; color: var(--bt-text); }
.bt-case-card-body p { margin: 0; font-size: 13px; color: var(--bt-muted); }

/* ── Why Us ── */
.bt-why { background: var(--bt-white); }
.bt-why-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.bt-why-card { padding: 32px 28px; border-radius: var(--bt-radius); border: 1px solid var(--bt-border); background: var(--bt-bg); }
.bt-why-card:hover { background: var(--bt-white); border-color: rgba(255,107,53,.2); }
.bt-why-card-num { display: inline-flex; align-items: center; justify-content: center; width: 36px; height: 36px; border-radius: 10px; background: var(--bt-accent); color: var(--bt-white); font-size: 14px; font-weight: 700; margin-bottom: 16px; }
.bt-why-card h3 { margin: 0 0 10px; font-size: 17px; font-weight: 700; color: var(--bt-text); }
.bt-why-card p { margin: 0; font-size: 14px; line-height: 1.7; color: var(--bt-muted); }

/* ── Stories ── */
.bt-stories { background: var(--bt-bg); }
.bt-stories-list { display: flex; flex-direction: column; gap: 32px; }
.bt-story-card { display: grid; grid-template-columns: 340px 1fr; gap: 40px; align-items: center; background: var(--bt-white); border-radius: var(--bt-radius-lg); overflow: hidden; box-shadow: var(--bt-shadow); }
.bt-story-card-img { height: 100%; min-height: 220px; overflow: hidden; }
.bt-story-card-img img { width: 100%; height: 100%; object-fit: cover; }
.bt-story-card-body { padding: 32px 32px 32px 0; }
.bt-story-card-body h3 { margin: 0 0 12px; font-size: 20px; font-weight: 700; color: var(--bt-text); }
.bt-story-card-body p { margin: 0 0 16px; font-size: 15px; line-height: 1.75; color: var(--bt-muted); }
.bt-story-card-meta { font-size: 13px; color: var(--bt-secondary); font-weight: 600; }

/* ── Logo Wall ── */
.bt-logos { background: var(--bt-white); padding: 72px 0; overflow: hidden; }
.bt-logos .bt-section-head { margin-bottom: 40px; }
.bt-logo-tracks { display: flex; flex-direction: column; gap: 24px; }
.bt-logo-track { display: flex; width: max-content; animation: btMarquee 40s linear infinite; }
.bt-logo-track:nth-child(2) { animation-direction: reverse; animation-duration: 35s; }
.bt-logo-track:hover { animation-play-state: paused; }
@keyframes btMarquee { 0% { transform: translateX(0); } 100% { transform: translateX(-50%); } }
.bt-logo-track-inner { display: flex; align-items: center; gap: 48px; padding: 0 24px; }
.bt-logo-item { flex-shrink: 0; width: 140px; height: 60px; display: flex; align-items: center; justify-content: center; filter: grayscale(100%); opacity: .55; transition: all var(--bt-transition); }
.bt-logo-item img { max-width: 100%; max-height: 100%; object-fit: contain; }
.bt-logo-item:hover { filter: grayscale(0); opacity: 1; }

/* ── News ── */
.bt-news { background: var(--bt-bg); }
.bt-news-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.bt-news-card { background: var(--bt-white); border-radius: var(--bt-radius); overflow: hidden; border: 1px solid var(--bt-border); }
.bt-news-card-img { aspect-ratio: 16/9; overflow: hidden; }
.bt-news-card-img img { width: 100%; height: 100%; object-fit: cover; transition: transform .5s ease; }
.bt-news-card:hover .bt-news-card-img img { transform: scale(1.04); }
.bt-news-card-body { padding: 24px; }
.bt-news-date { font-size: 13px; color: var(--bt-muted); margin-bottom: 8px; }
.bt-news-card-body h3 { margin: 0 0 10px; font-size: 17px; font-weight: 700; line-height: 1.4; color: var(--bt-text); display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.bt-news-card-body h3 a:hover { color: var(--bt-secondary); }
.bt-news-card-body p { margin: 0; font-size: 14px; line-height: 1.6; color: var(--bt-muted); display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }

/* ── CTA Form ── */
.bt-cta { background: var(--bt-dark); color: var(--bt-white); padding: 96px 0; }
.bt-cta .bt-container { display: grid; grid-template-columns: 1fr 1fr; gap: 64px; align-items: center; }
.bt-cta-copy h2 { margin: 0 0 16px; font-size: clamp(28px, 4vw, 36px); font-weight: 700; line-height: 1.25; }
.bt-cta-copy p { margin: 0 0 24px; font-size: 16px; line-height: 1.75; color: rgba(255,255,255,.7); }
.bt-cta-copy .bt-header-phone { font-size: 20px; color: var(--bt-accent); }

.bt-form { background: rgba(255,255,255,.04); border: 1px solid rgba(255,255,255,.1); border-radius: var(--bt-radius-lg); padding: 36px; }
.bt-form-group { margin-bottom: 16px; }
.bt-form-group label { display: block; margin-bottom: 6px; font-size: 13px; font-weight: 500; color: rgba(255,255,255,.7); }
.bt-form-group input, .bt-form-group textarea, .bt-form-group select { width: 100%; padding: 12px 16px; border: 1px solid rgba(255,255,255,.15); border-radius: 8px; background: rgba(255,255,255,.06); color: var(--bt-white); font: 15px var(--bt-font); box-sizing: border-box; transition: border-color var(--bt-transition); }
.bt-form-group input::placeholder, .bt-form-group textarea::placeholder { color: rgba(255,255,255,.35); }
.bt-form-group input:focus, .bt-form-group textarea:focus, .bt-form-group select:focus { outline: none; border-color: var(--bt-accent); }
.bt-form-group textarea { min-height: 100px; resize: vertical; }
.bt-form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.bt-form .bt-btn-primary { width: 100%; margin-top: 8px; padding: 16px; font-size: 16px; }

/* ── Footer ── */
.bt-footer { background: #060d18; color: rgba(255,255,255,.7); padding-top: 72px; }
.bt-footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1fr; gap: 40px; padding-bottom: 48px; }
.bt-footer-brand img { height: 40px; margin-bottom: 16px; }
.bt-footer-brand p { margin: 0; font-size: 14px; line-height: 1.7; max-width: 280px; }
.bt-footer-col h4 { margin: 0 0 20px; font-size: 15px; font-weight: 700; color: var(--bt-white); }
.bt-footer-col ul li { margin-bottom: 10px; }
.bt-footer-col a { font-size: 14px; color: rgba(255,255,255,.6); transition: color var(--bt-transition); }
.bt-footer-col a:hover { color: var(--bt-accent); }
.bt-footer-contact li { display: flex; align-items: flex-start; gap: 10px; font-size: 14px; line-height: 1.6; }
.bt-footer-bar { border-top: 1px solid rgba(255,255,255,.08); padding: 20px 0; text-align: center; font-size: 13px; color: rgba(255,255,255,.4); }
.bt-footer-bar a { color: rgba(255,255,255,.5); }
.bt-footer-bar a:hover { color: var(--bt-accent); }

/* ── Float ── */
.bt-float { position: fixed; right: 24px; bottom: 32px; z-index: 999; display: flex; flex-direction: column; gap: 12px; }
.bt-float-btn { display: flex; align-items: center; justify-content: center; width: 52px; height: 52px; border-radius: 50%; background: var(--bt-white); color: var(--bt-primary); box-shadow: 0 4px 20px rgba(10,36,99,.18); cursor: pointer; border: none; font-size: 22px; transition: all var(--bt-transition); position: relative; }
.bt-float-btn:hover { transform: translateY(-4px); box-shadow: 0 8px 28px rgba(10,36,99,.24); background: var(--bt-accent); color: var(--bt-white); }
.bt-float-btn-phone { background: var(--bt-accent); color: var(--bt-white); }
.bt-float-btn-phone:hover { background: var(--bt-accent-hover); }
.bt-float-tip { position: absolute; right: calc(100% + 12px); top: 50%; transform: translateY(-50%); padding: 8px 14px; background: var(--bt-dark); color: var(--bt-white); font-size: 13px; white-space: nowrap; border-radius: 6px; opacity: 0; visibility: hidden; transition: all var(--bt-transition); pointer-events: none; }
.bt-float-btn:hover .bt-float-tip { opacity: 1; visibility: visible; }

/* ── Responsive 1100px ── */
@media (max-width: 1100px) {
  .bt-section { padding: 72px 0; }
  .bt-hero .bt-container { grid-template-columns: 1fr; gap: 40px; text-align: center; }
  .bt-hero-copy p { margin-left: auto; margin-right: auto; }
  .bt-hero-btns { justify-content: center; }
  .bt-hero-slider { max-width: 560px; margin: 0 auto; }
  .bt-stats-grid { grid-template-columns: repeat(2, 1fr); gap: 40px; }
  .bt-svc-cards, .bt-cases-grid, .bt-why-grid, .bt-news-grid { grid-template-columns: repeat(2, 1fr); }
  .bt-process-steps { flex-wrap: wrap; gap: 24px; justify-content: center; }
  .bt-process-step { flex: 0 0 calc(33.333% - 16px); }
  .bt-process-step::after { display: none; }
  .bt-story-card { grid-template-columns: 280px 1fr; gap: 28px; }
  .bt-cta .bt-container { grid-template-columns: 1fr; gap: 40px; }
  .bt-footer-grid { grid-template-columns: repeat(2, 1fr); }
}

/* ── Responsive 768px ── */
@media (max-width: 768px) {
  :root { --bt-header-h: 60px; }
  .bt-container { padding: 0 16px; }
  .bt-section { padding: 56px 0; }
  .bt-section-head { margin-bottom: 36px; }
  .bt-nav, .bt-header-actions .bt-header-phone, .bt-header-actions .bt-btn-primary { display: none; }
  .bt-burger { display: flex; }
  .bt-header .bt-logo img { height: 36px; }
  .bt-hero { min-height: auto; padding: calc(var(--bt-header-h) + 32px) 0 100px; }
  .bt-trust .bt-container { flex-direction: column; gap: 12px; align-items: flex-start; }
  .bt-stats { clip-path: none; padding-top: 56px; }
  .bt-stats-grid { gap: 28px; }
  .bt-tabs { gap: 4px; overflow-x: auto; justify-content: flex-start; flex-wrap: nowrap; -webkit-overflow-scrolling: touch; scrollbar-width: none; }
  .bt-tabs::-webkit-scrollbar { display: none; }
  .bt-tab { padding: 12px 16px; font-size: 14px; white-space: nowrap; }
  .bt-svc-cards, .bt-cases-grid, .bt-why-grid, .bt-news-grid { grid-template-columns: 1fr; }
  .bt-process-steps { flex-direction: column; align-items: stretch; gap: 0; padding-left: 28px; border-left: 2px dashed rgba(21,101,192,.25); }
  .bt-process-step { flex: none; text-align: left; padding: 0 0 32px 24px; }
  .bt-process-step::after { display: none; }
  .bt-process-num { position: absolute; left: -28px; top: 0; width: 48px; height: 48px; margin: 0; transform: translateX(-50%); font-size: 16px; }
  .bt-story-card { grid-template-columns: 1fr; }
  .bt-story-card-img { min-height: 200px; }
  .bt-story-card-body { padding: 24px; }
  .bt-form-row { grid-template-columns: 1fr; }
  .bt-form { padding: 24px; }
  .bt-footer-grid { grid-template-columns: 1fr; gap: 32px; }
  .bt-float { right: 16px; bottom: 20px; }
  .bt-float-btn { width: 46px; height: 46px; font-size: 20px; }
  .bt-float-tip { display: none; }
}