/* ==========================================================
   BanYi CNC — main.css
   现代工业风 · 参考 www.accurl.com
   深蓝黑 #0d1421 + 工业红 #e8352e
   ========================================================== */

:root {
  --c-dark: #0d1421;
  --c-dark2: #16213e;
  --c-dark3: #1f2c4d;
  --c-accent: #e8352e;
  --c-accent2: #f04e23;
  --c-steel: #8a93a6;
  --c-bg: #ffffff;
  --c-bg-light: #f4f6fa;
  --c-bg-gray: #eceff5;
  --c-text: #1f2733;
  --c-text-2: #4a5568;
  --c-text-light: #6b7280;
  --c-border: #e2e8f0;
  --c-white: #ffffff;
  --radius: 6px;
  --radius-lg: 10px;
  --shadow: 0 4px 20px rgba(13, 20, 33, 0.08);
  --shadow-lg: 0 12px 40px rgba(13, 20, 33, 0.15);
  --trans: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --font-body: 'Roboto', -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-head: 'Oswald', 'Roboto', "PingFang SC", "Microsoft YaHei", sans-serif;
}

/* ---------- 基础 ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
  color: var(--c-text);
  background: var(--c-bg);
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--c-accent); text-decoration: none; transition: var(--trans); }
a:hover { color: var(--c-accent2); }
h1, h2, h3, h4 { font-family: var(--font-head); line-height: 1.25; color: var(--c-dark); font-weight: 600; }
.skip-link { position: absolute; left: -9999px; top: 0; background: var(--c-accent); color: #fff; padding: 8px 16px; z-index: 999; }
.skip-link:focus { left: 0; }
.by-container { max-width: 1280px; margin: 0 auto; padding: 0 24px; }
.by-icon { vertical-align: -2px; margin-right: 6px; }

/* ---------- 按钮 ---------- */
.by-btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  font-family: var(--font-body); font-weight: 700; font-size: 14px;
  letter-spacing: 0.5px; text-transform: uppercase;
  padding: 14px 30px; border-radius: 3px; cursor: pointer;
  transition: var(--trans); border: 2px solid transparent; text-align: center;
}
.by-btn-primary, .by-btn:not(.by-btn-outline):not(.by-btn-wa) {
  background: var(--c-accent); color: var(--c-white) !important;
}
.by-btn-primary:hover, .by-btn:not(.by-btn-outline):not(.by-btn-wa):hover {
  background: var(--c-accent2); color: var(--c-white) !important;
  transform: translateY(-2px); box-shadow: 0 8px 24px rgba(232, 53, 46, 0.35);
}
.by-btn-outline {
  background: transparent; color: var(--c-white) !important; border-color: rgba(255,255,255,0.6);
}
.by-btn-outline:hover { background: rgba(255,255,255,0.12); border-color: #fff; color: #fff !important; }
.by-btn-wa { background: #25d366; color: #fff !important; }
.by-btn-wa:hover { background: #1db854; transform: translateY(-2px); box-shadow: 0 8px 24px rgba(37,211,102,0.35); }
.by-btn-lg { padding: 16px 36px; font-size: 15px; }
.by-btn-sm { padding: 10px 20px; font-size: 13px; }

/* ---------- 顶部信息条 ---------- */
.by-topbar {
  background: var(--c-dark); color: #c9d2e0; font-size: 13px;
  border-bottom: 1px solid rgba(255,255,255,0.06);
}
.by-topbar-inner { display: flex; justify-content: space-between; align-items: center; min-height: 42px; gap: 16px; }
.by-topbar-left, .by-topbar-right { display: flex; align-items: center; gap: 20px; }
.by-topbar-item { color: #c9d2e0; display: inline-flex; align-items: center; }
.by-topbar-item:hover { color: var(--c-accent); }
.by-whatsapp:hover { color: #25d366; }
.by-lang-switch { display: flex; align-items: center; gap: 6px; }
.by-lang-switch a { color: #c9d2e0; font-weight: 500; padding: 2px 6px; border-radius: 2px; }
.by-lang-switch a.active { color: #fff; background: var(--c-accent); }
.by-lang-sep { color: #4a5568; }

/* ---------- 主导航 ---------- */
.by-header {
  background: var(--c-white);
  box-shadow: 0 2px 12px rgba(13,20,33,0.06);
  position: sticky; top: 0; z-index: 100;
}
.by-header-inner { display: flex; align-items: center; justify-content: space-between; min-height: 76px; gap: 24px; }
.by-logo { display: flex; align-items: center; flex-shrink: 0; }
.by-logo-text { font-family: var(--font-head); font-size: 30px; font-weight: 700; color: var(--c-dark); letter-spacing: -0.5px; }
.by-logo-text .by-logo-accent { color: var(--c-accent); }
.by-logo-sub { font-size: 13px; font-weight: 500; color: var(--c-steel); margin-left: 4px; vertical-align: 2px; letter-spacing: 2px; }
.by-logo img { max-height: 44px; width: auto; }

.by-nav ul.menu, .by-nav > ul { display: flex; align-items: center; gap: 4px; list-style: none; }
.by-nav li { position: relative; }
.by-nav a {
  display: block; padding: 12px 16px; color: var(--c-text); font-weight: 500; font-size: 15px;
  border-bottom: 2px solid transparent;
}
.by-nav a:hover, .by-nav .current-menu-item > a { color: var(--c-accent); border-bottom-color: var(--c-accent); }
/* 下拉菜单 */
.by-nav .sub-menu {
  display: none; position: absolute; top: 100%; left: 0; min-width: 260px;
  background: var(--c-white); box-shadow: var(--shadow-lg); border-radius: 0 0 var(--radius) var(--radius);
  padding: 8px 0; z-index: 200; border-top: 3px solid var(--c-accent); list-style: none;
}
.by-nav li:hover > .sub-menu { display: block; }
.by-nav .sub-menu a { padding: 11px 20px; font-size: 14px; border-bottom: none; color: var(--c-text); }
.by-nav .sub-menu a:hover { background: var(--c-bg-light); color: var(--c-accent); }
.by-header-cta { flex-shrink: 0; }

/* 移动菜单按钮 */
.by-menu-toggle { display: none; flex-direction: column; gap: 5px; background: none; border: none; cursor: pointer; padding: 8px; }
.by-menu-toggle span { width: 26px; height: 3px; background: var(--c-dark); border-radius: 2px; transition: var(--trans); }

/* ---------- HERO ---------- */
.by-hero { position: relative; min-height: 92vh; display: flex; align-items: center; overflow: hidden; }
.by-hero-bg { position: absolute; inset: 0; background-size: cover; background-position: center; transform: scale(1.05); animation: heroZoom 20s ease-in-out infinite alternate; }
@keyframes heroZoom { from { transform: scale(1.02); } to { transform: scale(1.12); } }
.by-hero-overlay { position: absolute; inset: 0; background: linear-gradient(105deg, rgba(13,20,33,0.94) 0%, rgba(13,20,33,0.78) 45%, rgba(13,20,33,0.35) 100%); }
.by-hero-inner { position: relative; z-index: 2; padding-top: 90px; padding-bottom: 60px; }
.by-hero-badge {
  display: inline-block; background: rgba(232,53,46,0.15); border: 1px solid rgba(232,53,46,0.5);
  color: #ff8a85; padding: 8px 18px; border-radius: 30px; font-size: 13px; font-weight: 600;
  letter-spacing: 1.5px; text-transform: uppercase; margin-bottom: 26px;
}
.by-hero-title { font-size: clamp(38px, 6vw, 68px); font-weight: 700; color: var(--c-white); letter-spacing: 1px; text-transform: uppercase; margin-bottom: 20px; max-width: 820px; }
.by-hero-sub { font-size: clamp(16px, 2vw, 20px); color: #c9d2e0; max-width: 680px; margin-bottom: 36px; line-height: 1.8; }
.by-hero-actions { display: flex; gap: 16px; flex-wrap: wrap; margin-bottom: 56px; }
.by-hero-kpis { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1px; background: rgba(255,255,255,0.1); border: 1px solid rgba(255,255,255,0.14); border-radius: var(--radius-lg); overflow: hidden; max-width: 860px; backdrop-filter: blur(8px); }
.by-hero-kpi { background: rgba(13,20,33,0.55); padding: 22px 20px; text-align: center; }
.by-hero-kpi strong { display: block; font-family: var(--font-head); font-size: 30px; color: var(--c-white); font-weight: 700; }
.by-hero-kpi strong small { font-size: 16px; color: var(--c-accent); font-weight: 600; margin-left: 2px; }
.by-hero-kpi span { display: block; font-size: 12.5px; color: #9aa5b8; margin-top: 4px; letter-spacing: 0.5px; text-transform: uppercase; }

/* ---------- 数据条 ---------- */
.by-stats { background: var(--c-dark); border-bottom: 4px solid var(--c-accent); }
.by-stats-inner { display: grid; grid-template-columns: repeat(4, 1fr); }
.by-stat { padding: 40px 20px; text-align: center; border-left: 1px solid rgba(255,255,255,0.08); }
.by-stat:first-child { border-left: none; }
.by-stat strong { display: block; font-family: var(--font-head); font-size: 44px; font-weight: 700; color: var(--c-white); }
.by-stat strong span { color: var(--c-accent); }
.by-stat > span { display: block; color: #9aa5b8; font-size: 14px; margin-top: 6px; letter-spacing: 0.5px; text-transform: uppercase; }

/* ---------- 通用 Section ---------- */
.by-section { padding: 88px 0; }
.by-section-head { text-align: center; max-width: 760px; margin: 0 auto 54px; }
.by-section-label {
  display: inline-block; color: var(--c-accent); font-weight: 700; font-size: 13px;
  letter-spacing: 2.5px; text-transform: uppercase; margin-bottom: 14px;
  position: relative; padding: 0 34px;
}
.by-section-label::before, .by-section-label::after {
  content: ""; position: absolute; top: 50%; width: 24px; height: 2px; background: var(--c-accent);
}
.by-section-label::before { left: 0; }
.by-section-label::after { right: 0; }
.by-section-title { font-size: clamp(28px, 4vw, 42px); font-weight: 700; text-transform: uppercase; letter-spacing: 0.5px; }
.by-section-sub { color: var(--c-text-light); font-size: 17px; margin-top: 14px; }
.by-section-head-light .by-section-title, .by-section-head-light .by-section-sub { color: var(--c-white); }
.by-section-head-light .by-section-sub { color: #b8c2d4; }

/* ---------- 产品分类卡片（首页） ---------- */
.by-products-section { background: var(--c-bg-light); }
.by-cat-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.by-cat-card {
  background: var(--c-white); border-radius: var(--radius-lg); overflow: hidden;
  box-shadow: var(--shadow); transition: var(--trans); display: flex; flex-direction: column;
  position: relative; border-bottom: 3px solid transparent;
}
.by-cat-card:hover { transform: translateY(-8px); box-shadow: var(--shadow-lg); border-bottom-color: var(--c-accent); }
.by-cat-card-img { aspect-ratio: 16/10; overflow: hidden; background: var(--c-bg-gray); }
.by-cat-card-img img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.6s ease; }
.by-cat-card:hover .by-cat-card-img img { transform: scale(1.08); }
.by-cat-card-body { padding: 22px; flex: 1; display: flex; flex-direction: column; }
.by-cat-card-title { font-size: 17px; font-weight: 700; color: var(--c-dark); margin-bottom: 8px; text-transform: uppercase; letter-spacing: 0.3px; }
.by-cat-card-desc { font-size: 13.5px; color: var(--c-text-light); line-height: 1.6; flex: 1; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.by-cat-card-meta { display: flex; justify-content: space-between; align-items: center; margin-top: 14px; padding-top: 14px; border-top: 1px solid var(--c-border); font-size: 13px; font-weight: 700; color: var(--c-accent); text-transform: uppercase; letter-spacing: 0.5px; }
.by-cat-arrow { transition: transform 0.3s; font-size: 16px; }
.by-cat-card:hover .by-cat-arrow { transform: translateX(6px); }

/* ---------- 精选产品（深色区） ---------- */
.by-featured-section { background: var(--c-dark); position: relative; }
.by-featured-section::before {
  content: ""; position: absolute; inset: 0; opacity: 0.04;
  background-image: repeating-linear-gradient(45deg, #fff 0, #fff 1px, transparent 1px, transparent 12px);
}
.by-featured-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; position: relative; }
.by-featured-card { background: var(--c-dark2); border-radius: var(--radius-lg); overflow: hidden; transition: var(--trans); border: 1px solid rgba(255,255,255,0.07); }
.by-featured-card:hover { transform: translateY(-8px); border-color: var(--c-accent); box-shadow: 0 20px 50px rgba(0,0,0,0.4); }
.by-featured-card-img { position: relative; aspect-ratio: 4/3; overflow: hidden; background: var(--c-dark3); }
.by-featured-card-img img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.6s ease; }
.by-featured-card:hover .by-featured-card-img img { transform: scale(1.07); }
.by-featured-badge {
  position: absolute; top: 14px; left: 14px; background: var(--c-accent); color: #fff;
  font-family: var(--font-head); font-weight: 700; font-size: 15px; padding: 6px 14px; border-radius: 3px;
}
.by-featured-card-body { padding: 22px; }
.by-featured-card-title { font-size: 17px; color: var(--c-white); font-weight: 700; margin-bottom: 8px; text-transform: uppercase; }
.by-featured-card-tag { font-size: 13px; color: #9aa5b8; line-height: 1.6; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.by-featured-link { display: inline-block; margin-top: 14px; color: var(--c-accent); font-size: 13px; font-weight: 700; text-transform: uppercase; letter-spacing: 1px; }

/* ---------- 核心技术 ---------- */
.by-tech-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.by-tech-item {
  background: var(--c-white); border: 1px solid var(--c-border); border-radius: var(--radius-lg);
  padding: 30px 26px; transition: var(--trans); position: relative; overflow: hidden;
}
.by-tech-item::before { content: ""; position: absolute; top: 0; left: 0; width: 100%; height: 4px; background: var(--c-accent); transform: scaleX(0); transform-origin: left; transition: transform 0.4s; }
.by-tech-item:hover { box-shadow: var(--shadow-lg); transform: translateY(-6px); }
.by-tech-item:hover::before { transform: scaleX(1); }
.by-tech-num { font-family: var(--font-head); font-size: 46px; font-weight: 700; color: var(--c-bg-gray); line-height: 1; display: block; margin-bottom: 14px; transition: var(--trans); }
.by-tech-item:hover .by-tech-num { color: var(--c-accent); }
.by-tech-title { font-size: 16.5px; font-weight: 700; margin-bottom: 10px; text-transform: uppercase; }
.by-tech-desc { font-size: 13.5px; color: var(--c-text-light); line-height: 1.7; }

/* ---------- 应用领域 ---------- */
.by-apps-section { background: var(--c-dark2); }
.by-apps-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 2px; background: rgba(255,255,255,0.08); }
.by-app-item { background: var(--c-dark2); padding: 32px 24px; text-align: center; transition: var(--trans); }
.by-app-item:hover { background: var(--c-accent); }
.by-app-title { display: block; font-family: var(--font-head); font-size: 18px; font-weight: 600; color: var(--c-white); text-transform: uppercase; letter-spacing: 1px; }
.by-app-sub { display: block; font-size: 12px; color: #8a93a6; margin-top: 4px; letter-spacing: 0.5px; }
.by-app-item:hover .by-app-sub { color: rgba(255,255,255,0.85); }
.by-apps-grid-lg { gap: 20px; background: none; }
.by-app-item-lg { background: var(--c-white); border: 1px solid var(--c-border); border-radius: var(--radius-lg); box-shadow: var(--shadow); }
.by-app-item-lg .by-app-title { color: var(--c-dark); }
.by-app-item-lg .by-app-desc { font-size: 13.5px; color: var(--c-text-light); margin-top: 12px; }
.by-app-item-lg:hover { background: var(--c-white); border-color: var(--c-accent); }

/* ---------- 客户案例 ---------- */
.by-cases-section { background: var(--c-bg-light); }
.by-cases-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.by-case-item { background: var(--c-white); border-radius: var(--radius-lg); padding: 24px; box-shadow: var(--shadow); border-left: 4px solid var(--c-accent); transition: var(--trans); }
.by-case-item:hover { transform: translateX(6px); }
.by-case-flag { font-weight: 700; color: var(--c-dark); font-size: 16px; margin-bottom: 6px; }
.by-case-desc { font-size: 14px; color: var(--c-text-light); }

/* ---------- CTA ---------- */
.by-cta {
  background: linear-gradient(120deg, var(--c-dark) 0%, var(--c-dark3) 100%);
  position: relative; overflow: hidden;
}
.by-cta::before {
  content: ""; position: absolute; right: -80px; top: -80px; width: 420px; height: 420px;
  background: var(--c-accent); opacity: 0.14; border-radius: 50%; filter: blur(60px);
}
.by-cta-inner { display: flex; align-items: center; justify-content: space-between; gap: 36px; padding: 64px 24px; position: relative; flex-wrap: wrap; }
.by-cta-text h2 { color: var(--c-white); font-size: clamp(26px, 3.5vw, 38px); text-transform: uppercase; margin-bottom: 10px; }
.by-cta-text p { color: #b8c2d4; font-size: 17px; }
.by-cta-actions { display: flex; gap: 14px; flex-wrap: wrap; }

/* ---------- 页脚 ---------- */
.by-footer { background: #0a0f1a; color: #9aa5b8; padding-top: 64px; }
.by-footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1.2fr; gap: 44px; padding-bottom: 48px; }
.by-footer-logo { font-family: var(--font-head); font-size: 28px; font-weight: 700; color: var(--c-white); margin-bottom: 16px; }
.by-footer-logo .by-logo-accent { color: var(--c-accent); }
.by-footer-logo .by-logo-sub { font-size: 12px; color: var(--c-steel); letter-spacing: 2px; }
.by-footer-desc { font-size: 14px; line-height: 1.8; margin-bottom: 22px; }
.by-footer-stats { display: flex; gap: 28px; }
.by-footer-stat strong { display: block; font-family: var(--font-head); font-size: 26px; color: var(--c-accent); }
.by-footer-stat span { font-size: 12px; text-transform: uppercase; letter-spacing: 0.5px; }
.by-footer-title { color: var(--c-white); font-size: 16px; font-weight: 700; text-transform: uppercase; letter-spacing: 1px; margin-bottom: 20px; padding-bottom: 12px; position: relative; }
.by-footer-title::after { content: ""; position: absolute; left: 0; bottom: 0; width: 34px; height: 3px; background: var(--c-accent); }
.by-footer-links { list-style: none; }
.by-footer-links li { margin-bottom: 10px; }
.by-footer-links a { color: #9aa5b8; font-size: 14px; }
.by-footer-links a:hover { color: var(--c-accent); padding-left: 5px; }
.by-footer-contact { list-style: none; margin-bottom: 20px; }
.by-footer-contact li { display: flex; align-items: flex-start; gap: 10px; margin-bottom: 14px; font-size: 14px; }
.by-footer-contact svg { color: var(--c-accent); flex-shrink: 0; margin-top: 3px; }
.by-footer-contact a { color: #9aa5b8; }
.by-footer-contact a:hover { color: var(--c-accent); }
.by-footer-bottom { border-top: 1px solid rgba(255,255,255,0.07); padding: 22px 0; }
.by-footer-bottom-inner { display: flex; justify-content: space-between; align-items: center; gap: 16px; flex-wrap: wrap; font-size: 13px; }
.by-footer-bottom-links a { color: #9aa5b8; }
.by-footer-bottom-links a:hover { color: var(--c-accent); }
.by-footer-bottom-links span { margin: 0 8px; color: #4a5568; }

/* ---------- 面包屑 ---------- */
.by-breadcrumb { padding: 18px 24px 0; font-size: 13.5px; color: var(--c-text-light); }
.by-breadcrumb a { color: var(--c-text-light); }
.by-breadcrumb a:hover { color: var(--c-accent); }
.by-bc-sep { margin: 0 8px; color: var(--c-border); }
.by-bc-current { color: var(--c-text); font-weight: 500; }

/* ---------- 分类/技术 Hero ---------- */
.by-cat-hero { position: relative; background-size: cover; background-position: center; padding: 90px 0; }
.by-cat-hero-plain { background: var(--c-dark); }
.by-cat-hero-overlay { position: absolute; inset: 0; background: linear-gradient(100deg, rgba(13,20,33,0.93) 0%, rgba(13,20,33,0.72) 100%); }
.by-cat-hero-inner { position: relative; z-index: 2; }
.by-cat-hero-num { font-family: var(--font-head); font-size: 64px; font-weight: 700; color: var(--c-accent); line-height: 1; display: block; margin-bottom: 8px; }
.by-cat-hero-title { font-size: clamp(30px, 4.5vw, 48px); color: var(--c-white); text-transform: uppercase; font-weight: 700; }
.by-cat-hero-sub { font-size: clamp(16px, 2.2vw, 22px); color: var(--c-accent); font-weight: 600; margin-top: 8px; }
.by-cat-hero-desc { color: #c9d2e0; font-size: 16.5px; max-width: 720px; margin-top: 16px; line-height: 1.8; }
.by-cat-hero-count { display: inline-block; margin-top: 20px; background: var(--c-accent); color: #fff; font-weight: 700; font-size: 14px; padding: 7px 18px; border-radius: 30px; text-transform: uppercase; letter-spacing: 1px; }

/* ---------- 产品卡片（分类页/总览页） ---------- */
.by-cat-block { margin-bottom: 72px; }
.by-cat-block-head { display: flex; justify-content: space-between; align-items: flex-end; gap: 20px; margin-bottom: 28px; padding-bottom: 18px; border-bottom: 3px solid var(--c-accent); }
.by-cat-block-title { font-size: clamp(22px, 3vw, 30px); text-transform: uppercase; }
.by-cat-block-sub { color: var(--c-text-light); margin-top: 4px; }
.by-cat-block-count { background: var(--c-dark); color: #fff; font-weight: 700; font-size: 14px; padding: 8px 18px; border-radius: 30px; white-space: nowrap; }

.by-product-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; }
.by-product-card { background: var(--c-white); border: 1px solid var(--c-border); border-radius: var(--radius-lg); overflow: hidden; transition: var(--trans); display: flex; flex-direction: column; }
.by-product-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-8px); border-color: var(--c-accent); }
.by-product-card-img { position: relative; aspect-ratio: 16/10; overflow: hidden; background: var(--c-bg-gray); }
.by-product-card-img img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.6s ease; }
.by-product-card:hover .by-product-card-img img { transform: scale(1.07); }
.by-product-card-badge { position: absolute; top: 14px; left: 14px; background: var(--c-accent); color: #fff; font-family: var(--font-head); font-weight: 700; font-size: 15px; padding: 6px 14px; border-radius: 3px; }
.by-product-card-body { padding: 24px; flex: 1; display: flex; flex-direction: column; }
.by-product-card-title { font-size: 17.5px; font-weight: 700; color: var(--c-dark); margin-bottom: 4px; }
.by-product-card-title-alt { font-size: 13px; color: var(--c-steel); margin-bottom: 10px; }
.by-product-card-tag { font-size: 14px; color: var(--c-text-light); line-height: 1.65; flex: 1; }
.by-product-card-kws { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; margin: 16px 0; padding: 14px 0; border-top: 1px solid var(--c-border); }
.by-product-card-kw { text-align: center; }
.by-product-card-kw strong { display: block; font-family: var(--font-head); font-size: 17px; color: var(--c-accent); }
.by-product-card-kw span { display: block; font-size: 11px; color: var(--c-text-light); text-transform: uppercase; letter-spacing: 0.3px; margin-top: 2px; }
.by-product-card-link { color: var(--c-accent); font-weight: 700; font-size: 13.5px; text-transform: uppercase; letter-spacing: 0.8px; }

/* ---------- 产品详情页 ---------- */
.by-pd-hero { background: var(--c-bg-light); padding: 54px 0 64px; border-bottom: 1px solid var(--c-border); }
.by-pd-hero-grid { display: grid; grid-template-columns: 1.1fr 1fr; gap: 56px; align-items: center; }
.by-pd-cat-badge { display: inline-block; background: var(--c-dark); color: #fff; font-size: 12.5px; font-weight: 700; padding: 6px 14px; border-radius: 3px; text-transform: uppercase; letter-spacing: 1px; margin-bottom: 18px; }
.by-pd-title { font-size: clamp(26px, 3.6vw, 42px); font-weight: 700; text-transform: uppercase; line-height: 1.15; }
.by-pd-title-zh { font-size: clamp(17px, 2.2vw, 24px); color: var(--c-accent); font-weight: 600; margin-top: 8px; }
.by-pd-tagline { color: var(--c-text-2); font-size: 16.5px; margin: 18px 0 26px; line-height: 1.75; }
.by-pd-kpis { display: grid; grid-template-columns: repeat(auto-fit, minmax(110px, 1fr)); gap: 12px; margin-bottom: 30px; }
.by-pd-kpi { background: var(--c-white); border: 1px solid var(--c-border); border-top: 3px solid var(--c-accent); border-radius: var(--radius); padding: 16px 12px; text-align: center; }
.by-pd-kpi strong { display: block; font-family: var(--font-head); font-size: 21px; color: var(--c-dark); }
.by-pd-kpi span { display: block; font-size: 11.5px; color: var(--c-text-light); margin-top: 4px; text-transform: uppercase; letter-spacing: 0.3px; }
.by-pd-actions { display: flex; gap: 14px; flex-wrap: wrap; }
.by-pd-actions .by-btn-outline { color: var(--c-dark) !important; border-color: var(--c-dark); }
.by-pd-actions .by-btn-outline:hover { background: var(--c-dark); color: #fff !important; }
.by-pd-hero-img { background: var(--c-white); border-radius: var(--radius-lg); overflow: hidden; box-shadow: var(--shadow-lg); }
.by-pd-hero-img img { width: 100%; }

.by-pd-overview { max-width: 880px; }
.by-pd-overview p { font-size: 16.5px; line-height: 1.85; color: var(--c-text-2); margin-bottom: 18px; }

.by-features-section { background: var(--c-dark); }
.by-pd-features-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; }
.by-pd-feature-card { background: var(--c-dark2); border: 1px solid rgba(255,255,255,0.08); border-radius: var(--radius-lg); padding: 30px; transition: var(--trans); position: relative; }
.by-pd-feature-card:hover { border-color: var(--c-accent); transform: translateY(-5px); }
.by-pd-feature-num { font-family: var(--font-head); font-size: 40px; font-weight: 700; color: rgba(232,53,46,0.35); display: block; margin-bottom: 12px; }
.by-pd-feature-title { font-size: 18px; color: var(--c-white); margin-bottom: 4px; text-transform: uppercase; }
.by-pd-feature-title-alt { font-size: 13px; color: var(--c-accent); margin-bottom: 12px; }
.by-pd-feature-desc { font-size: 14.5px; color: #a8b3c5; line-height: 1.75; }

.by-pd-specs-wrap { background: var(--c-white); border: 1px solid var(--c-border); border-radius: var(--radius-lg); overflow: hidden; box-shadow: var(--shadow); }
.by-pd-specs { width: 100%; border-collapse: collapse; }
.by-pd-specs th, .by-pd-specs td { padding: 15px 22px; text-align: left; border-bottom: 1px solid var(--c-border); }
.by-pd-specs thead th { background: var(--c-dark); color: var(--c-white); font-family: var(--font-head); font-size: 15px; letter-spacing: 1px; text-transform: uppercase; }
.by-pd-specs tbody tr:hover { background: var(--c-bg-light); }
.by-pd-specs tbody tr:last-child td { border-bottom: none; }
.by-spec-key .by-spec-en { display: block; font-weight: 600; color: var(--c-dark); font-size: 14.5px; }
.by-spec-key .by-spec-zh { display: block; font-size: 12.5px; color: var(--c-text-light); }
.by-spec-val { font-family: var(--font-head); color: var(--c-dark); font-weight: 600; font-size: 15px; }

/* ---------- 相关产品 ---------- */
.by-related-section { background: var(--c-bg-light); }
.by-related-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.by-related-card { background: var(--c-white); border-radius: var(--radius-lg); overflow: hidden; box-shadow: var(--shadow); transition: var(--trans); }
.by-related-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); }
.by-related-card-img { aspect-ratio: 16/10; overflow: hidden; background: var(--c-bg-gray); }
.by-related-card-img img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.5s; }
.by-related-card:hover img { transform: scale(1.06); }
.by-related-card-body { padding: 20px; }
.by-related-card-body h4 { font-size: 16px; color: var(--c-dark); margin-bottom: 6px; }
.by-related-card-body p { font-size: 13px; color: var(--c-text-light); }

/* ---------- 技术列表/详情 ---------- */
.by-tech-list-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.by-tech-list-card { background: var(--c-white); border: 1px solid var(--c-border); border-radius: var(--radius-lg); padding: 30px 26px; transition: var(--trans); display: flex; flex-direction: column; }
.by-tech-list-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-6px); border-top: 4px solid var(--c-accent); }
.by-tech-list-num { font-family: var(--font-head); font-size: 44px; font-weight: 700; color: var(--c-bg-gray); line-height: 1; margin-bottom: 14px; }
.by-tech-list-card:hover .by-tech-list-num { color: var(--c-accent); }
.by-tech-list-title { font-size: 17px; font-weight: 700; margin-bottom: 10px; text-transform: uppercase; }
.by-tech-list-desc { font-size: 13.5px; color: var(--c-text-light); flex: 1; line-height: 1.7; }
.by-tech-list-link { color: var(--c-accent); font-size: 13px; font-weight: 700; margin-top: 14px; text-transform: uppercase; letter-spacing: 1px; }
.by-tech-content { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: center; }
.by-tech-img { border-radius: var(--radius-lg); overflow: hidden; box-shadow: var(--shadow-lg); }
.by-tech-en { font-size: 16.5px; line-height: 1.85; color: var(--c-text-2); margin-bottom: 18px; }
.by-tech-zh { font-size: 15.5px; line-height: 1.85; color: var(--c-text-light); }

/* ---------- 关于页 ---------- */
.by-about-grid { display: grid; grid-template-columns: 1.6fr 1fr; gap: 48px; }
.by-about-text p { font-size: 16px; line-height: 1.85; color: var(--c-text-2); margin-bottom: 16px; }
.by-about-stats { display: flex; gap: 36px; margin-top: 30px; }
.by-about-stats .by-stat { padding: 0; text-align: left; border: none; }
.by-about-stats .by-stat strong { color: var(--c-accent); font-size: 36px; }
.by-about-stats .by-stat > span { color: var(--c-text-light); }
.by-about-card { background: var(--c-dark); border-radius: var(--radius-lg); padding: 32px; }
.by-about-card h3 { color: var(--c-white); font-size: 19px; margin-bottom: 20px; text-transform: uppercase; }
.by-about-list { list-style: none; }
.by-about-list li { padding: 14px 0; border-bottom: 1px solid rgba(255,255,255,0.08); }
.by-about-list li:last-child { border-bottom: none; }
.by-about-list strong { display: block; color: var(--c-white); font-size: 15px; }
.by-about-list span { display: block; font-size: 13px; color: #9aa5b8; margin-top: 3px; }

/* ---------- 联系页 ---------- */
.by-contact-grid { display: grid; grid-template-columns: 1fr 1.3fr; gap: 48px; }
.by-contact-items { margin: 24px 0 30px; }
.by-contact-item { display: flex; gap: 18px; align-items: flex-start; padding: 20px 0; border-bottom: 1px solid var(--c-border); }
.by-contact-icon { width: 48px; height: 48px; background: var(--c-dark); color: var(--c-accent); border-radius: var(--radius); display: flex; align-items: center; justify-content: center; flex-shrink: 0; }
.by-contact-item strong { display: block; color: var(--c-dark); font-size: 15px; margin-bottom: 3px; }
.by-contact-item a, .by-contact-item span { color: var(--c-text-light); font-size: 14.5px; }
.by-contact-form { background: var(--c-bg-light); border: 1px solid var(--c-border); border-radius: var(--radius-lg); padding: 36px; }
.by-contact-form label { display: block; font-weight: 600; font-size: 14px; color: var(--c-dark); margin-bottom: 16px; }
.by-contact-form input, .by-contact-form textarea {
  width: 100%; margin-top: 7px; padding: 12px 15px; border: 1px solid var(--c-border);
  border-radius: var(--radius); font-family: var(--font-body); font-size: 15px; transition: var(--trans);
  background: var(--c-white);
}
.by-contact-form input:focus, .by-contact-form textarea:focus { outline: none; border-color: var(--c-accent); box-shadow: 0 0 0 3px rgba(232,53,46,0.12); }
.by-form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }

/* ---------- 通用页面 ---------- */
.by-page-content { max-width: 860px; }
.by-page-title { font-size: 34px; text-transform: uppercase; margin-bottom: 26px; padding-bottom: 18px; border-bottom: 3px solid var(--c-accent); }
.by-page-body { font-size: 16px; line-height: 1.85; color: var(--c-text-2); }
.by-page-body h2 { margin: 30px 0 14px; font-size: 24px; }
.by-page-body h3 { margin: 24px 0 12px; font-size: 19px; }
.by-page-body p { margin-bottom: 14px; }
.by-page-body ul, .by-page-body ol { margin: 0 0 16px 24px; }
.by-page-body img { border-radius: var(--radius-lg); }
.by-notfound { text-align: center; padding: 120px 24px; }
.by-notfound h1 { font-size: 80px; color: var(--c-accent); }
.by-posts-list .by-post-item { padding: 28px 0; border-bottom: 1px solid var(--c-border); }
.by-posts-list h2 { font-size: 22px; }

/* ---------- 响应式 ---------- */
@media (max-width: 1100px) {
  .by-cat-grid, .by-featured-grid, .by-tech-grid, .by-tech-list-grid { grid-template-columns: repeat(2, 1fr); }
  .by-product-grid, .by-related-grid, .by-cases-grid { grid-template-columns: repeat(2, 1fr); }
  .by-footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 860px) {
  .by-header-cta { display: none; }
  .by-menu-toggle { display: flex; }
  .by-nav { position: fixed; top: 0; right: -100%; width: min(320px, 85vw); height: 100vh; background: var(--c-white); box-shadow: -10px 0 40px rgba(0,0,0,0.2); padding: 90px 0 30px; transition: right 0.35s ease; overflow-y: auto; z-index: 150; }
  .by-nav.open { right: 0; }
  .by-nav ul.menu, .by-nav > ul { flex-direction: column; align-items: stretch; gap: 0; }
  .by-nav a { padding: 15px 26px; border-bottom: 1px solid var(--c-border); }
  .by-nav .sub-menu { position: static; display: block; box-shadow: none; border-top: none; padding-left: 16px; }
  .by-menu-toggle.active span:nth-child(1) { transform: translateY(8px) rotate(45deg); }
  .by-menu-toggle.active span:nth-child(2) { opacity: 0; }
  .by-menu-toggle.active span:nth-child(3) { transform: translateY(-8px) rotate(-45deg); }
  .by-hero { min-height: auto; }
  .by-hero-kpis { grid-template-columns: repeat(2, 1fr); }
  .by-stats-inner { grid-template-columns: repeat(2, 1fr); }
  .by-pd-hero-grid, .by-tech-content, .by-about-grid, .by-contact-grid { grid-template-columns: 1fr; }
  .by-pd-features-grid { grid-template-columns: 1fr; }
  .by-topbar-left { display: none; }
  .by-topbar-inner { justify-content: center; }
}
@media (max-width: 560px) {
  .by-section { padding: 60px 0; }
  .by-cat-grid, .by-featured-grid, .by-tech-grid, .by-tech-list-grid,
  .by-product-grid, .by-related-grid, .by-cases-grid, .by-apps-grid { grid-template-columns: 1fr; }
  .by-footer-grid { grid-template-columns: 1fr; gap: 30px; }
  .by-form-row { grid-template-columns: 1fr; }
  .by-contact-form { padding: 24px; }
  .by-hero-actions .by-btn { width: 100%; }
  .by-cta-inner { flex-direction: column; text-align: center; justify-content: center; }
  .by-cat-block-head { flex-direction: column; align-items: flex-start; }
}

/* reveal-on-scroll animation */
.by-reveal{opacity:0;transform:translateY(24px);transition:opacity .6s ease,transform .6s ease}
.by-reveal.by-visible{opacity:1;transform:none}
.by-header.scrolled{box-shadow:0 4px 24px rgba(0,0,0,.35)}
.by-nav .menu-item-has-children.sub-open>.sub-menu{display:block}
body.by-nav-open{overflow:hidden}