/* ==========================================================================
   北京龙超智业商贸有限公司 · 官方网站
   工业蓝 · 专业稳重风格
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. 设计变量 (Design Tokens)
   -------------------------------------------------------------------------- */
:root {
  /* 品牌色 */
  --navy-900: #07263f;
  --navy-800: #0a3557;
  --navy-700: #0e4370;
  --blue-600: #1b6cb8;
  --blue-500: #2b7fc9;
  --blue-100: #e2eef9;
  --blue-50:  #f0f6fc;

  /* 强调色（能源 / 电） */
  --amber-500: #f0a500;
  --amber-400: #ffb929;
  --amber-50:  #fff7e8;

  /* 中性色 */
  --ink-900: #12283b;
  --ink-700: #34495c;
  --ink-500: #5b6b7b;
  --steel-400: #94a6b6;
  --line:     #e3eaf1;
  --bg-100:   #f5f8fb;
  --bg-50:    #fafcfe;
  --white:    #ffffff;

  /* 字体 */
  --font-sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei",
               "Noto Sans SC", "Source Han Sans SC", system-ui, -apple-system,
               "Segoe UI", Roboto, sans-serif;
  --font-num:  "DIN Alternate", "Bahnschrift", "Segoe UI", var(--font-sans);

  /* 尺寸 */
  --container: 1200px;
  --radius: 14px;
  --radius-sm: 9px;
  --shadow-sm: 0 1px 3px rgba(7, 38, 63, 0.06), 0 1px 2px rgba(7, 38, 63, 0.04);
  --shadow-md: 0 6px 20px rgba(7, 38, 63, 0.08);
  --shadow-lg: 0 18px 45px rgba(7, 38, 63, 0.14);

  --header-h: 72px;
  --transition: 0.28s cubic-bezier(0.4, 0, 0.2, 1);
}

/* --------------------------------------------------------------------------
   2. 基础重置
   -------------------------------------------------------------------------- */
*,
*::before,
*::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  color: var(--ink-700);
  background: var(--white);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4, h5 {
  margin: 0;
  color: var(--ink-900);
  font-weight: 700;
  line-height: 1.28;
  letter-spacing: 0.2px;
}

p { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
button, input, textarea, select { font: inherit; color: inherit; }
button { cursor: pointer; border: none; background: none; }
input, textarea, select { outline: none; }

/* --------------------------------------------------------------------------
   3. 工具类
   -------------------------------------------------------------------------- */
.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}

.section { padding: 88px 0; }
.section--alt { background: var(--bg-100); }
.section--navy { background: var(--navy-800); color: #cfe0ef; }

.section-head {
  max-width: 680px;
  margin: 0 auto 52px;
  text-align: center;
}

.section-head--left { margin-left: 0; text-align: left; }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 16px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 2px;
  color: var(--blue-600);
  text-transform: uppercase;
}

.eyebrow::before {
  content: "";
  width: 22px;
  height: 2px;
  background: var(--amber-500);
  border-radius: 2px;
}

.section-title {
  font-size: clamp(26px, 3.4vw, 38px);
  letter-spacing: 0.5px;
}

.section-desc {
  margin-top: 16px;
  font-size: 16px;
  color: var(--ink-500);
}

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 30px;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.5px;
  border-radius: 8px;
  transition: transform var(--transition), box-shadow var(--transition),
              background var(--transition), color var(--transition);
  white-space: nowrap;
}

.btn svg { width: 18px; height: 18px; flex: none; }

.btn--primary {
  background: var(--amber-500);
  color: var(--navy-900);
}
.btn--primary:hover {
  background: var(--amber-400);
  transform: translateY(-2px);
  box-shadow: 0 10px 24px rgba(240, 165, 0, 0.34);
}

.btn--ghost {
  background: rgba(255, 255, 255, 0.06);
  color: var(--white);
  border: 1px solid rgba(255, 255, 255, 0.28);
}
.btn--ghost:hover {
  background: rgba(255, 255, 255, 0.14);
  border-color: rgba(255, 255, 255, 0.5);
  transform: translateY(-2px);
}

.btn--outline {
  background: transparent;
  color: var(--blue-600);
  border: 1px solid var(--blue-600);
}
.btn--outline:hover {
  background: var(--blue-600);
  color: var(--white);
  transform: translateY(-2px);
}

/* 卡片 */
.card {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition), box-shadow var(--transition),
              border-color var(--transition);
}

/* 渐显动效 */
.reveal {
  opacity: 0;
  transform: translateY(26px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.reveal.in-view { opacity: 1; transform: none; }

/* --------------------------------------------------------------------------
   4. 顶部导航
   -------------------------------------------------------------------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-h);
  background: rgba(255, 255, 255, 0.97);
  border-bottom: 1px solid var(--line);
}

.site-header__inner {
  height: var(--header-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand { display: flex; align-items: center; gap: 12px; }
.brand__mark {
  width: 42px;
  height: 42px;
  flex: none;
  border-radius: 10px;
  display: grid;
  place-items: center;
  background: linear-gradient(135deg, var(--blue-600), var(--navy-800));
  box-shadow: var(--shadow-sm);
}
.brand__mark svg { width: 24px; height: 24px; }
.brand__text { line-height: 1.15; }
.brand__name { font-size: 18px; font-weight: 800; color: var(--ink-900); letter-spacing: 0.5px; }
.brand__sub {
  font-size: 10.5px;
  letter-spacing: 1.6px;
  color: var(--steel-400);
  text-transform: uppercase;
  margin-top: 2px;
}

.main-nav { display: flex; align-items: center; gap: 4px; }
.main-nav a {
  position: relative;
  padding: 8px 16px;
  font-size: 15px;
  font-weight: 500;
  color: var(--ink-700);
  border-radius: 7px;
  transition: color var(--transition), background var(--transition);
}
.main-nav a:hover { color: var(--blue-600); background: var(--blue-50); }
.main-nav a.active { color: var(--blue-600); font-weight: 700; }
.main-nav a.active::after {
  content: "";
  position: absolute;
  left: 16px;
  right: 16px;
  bottom: 2px;
  height: 2px;
  background: var(--amber-500);
  border-radius: 2px;
}

.header-cta { display: flex; align-items: center; gap: 12px; }
.header-phone {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  color: var(--navy-800);
  font-size: 15px;
  text-decoration: none;
}
.header-phone svg { width: 18px; height: 18px; color: var(--blue-600); }
.header-cta .btn { padding: 11px 22px; }

.nav-toggle {
  display: none;
  width: 42px;
  height: 42px;
  border-radius: 9px;
  border: 1px solid var(--line);
  place-items: center;
}
.nav-toggle svg { width: 22px; height: 22px; color: var(--ink-700); }

/* --------------------------------------------------------------------------
   5. Hero（首页主视觉）
   -------------------------------------------------------------------------- */
.hero {
  position: relative;
  overflow: hidden;
  color: var(--white);
  background:
    radial-gradient(1200px 600px at 85% -10%, rgba(43, 127, 201, 0.55), transparent 60%),
    radial-gradient(900px 500px at -10% 110%, rgba(240, 165, 0, 0.16), transparent 55%),
    linear-gradient(160deg, var(--navy-900) 0%, var(--navy-700) 60%, #0c2f4d 100%);
}

.hero__grid {
  position: relative;
  z-index: 2;
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 48px;
  align-items: center;
  padding: 108px 0 96px;
}

.hero__eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 7px 16px;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 1.5px;
  color: #ffd77a;
  background: rgba(240, 165, 0, 0.12);
  border: 1px solid rgba(240, 165, 0, 0.35);
  border-radius: 100px;
}
.hero__eyebrow svg { width: 15px; height: 15px; }

.hero__title {
  margin: 22px 0 20px;
  font-size: clamp(32px, 5vw, 52px);
  font-weight: 800;
  color: var(--white);
  letter-spacing: 1px;
  line-height: 1.22;
}
.hero__title .accent {
  color: var(--amber-400);
  position: relative;
}
.hero__sub {
  max-width: 520px;
  font-size: 17px;
  line-height: 1.85;
  color: #b9cfe2;
}
.hero__actions { display: flex; gap: 14px; margin-top: 34px; flex-wrap: wrap; }

.hero__stats {
  display: flex;
  gap: 40px;
  margin-top: 48px;
  padding-top: 30px;
  border-top: 1px solid rgba(255, 255, 255, 0.14);
}
.hero__stat .num {
  font-family: var(--font-num);
  font-size: 34px;
  font-weight: 800;
  color: var(--white);
  line-height: 1;
}
.hero__stat .num b { color: var(--amber-400); font-weight: 800; }
.hero__stat .label { margin-top: 8px; font-size: 13px; color: #93adc4; letter-spacing: 0.5px; }

/* Hero 右侧：发电机示意图 */
.hero__visual { position: relative; }
.hero__panel {
  position: relative;
  padding: 30px;
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.14);
  backdrop-filter: blur(4px);
}
.hero__panel svg { width: 100%; height: auto; }

.hero__badge {
  position: absolute;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 18px;
  background: rgba(255, 255, 255, 0.96);
  border-radius: 12px;
  box-shadow: var(--shadow-lg);
  color: var(--ink-900);
  animation: float 5s ease-in-out infinite;
}
.hero__badge--tl { top: -18px; left: -12px; }
.hero__badge--br { bottom: -18px; right: -8px; animation-delay: 1.4s; }
.hero__badge .ico {
  width: 40px;
  height: 40px;
  flex: none;
  border-radius: 9px;
  display: grid;
  place-items: center;
  background: var(--blue-50);
  color: var(--blue-600);
}
.hero__badge .ico svg { width: 22px; height: 22px; }
.hero__badge .t { font-size: 14px; font-weight: 700; }
.hero__badge .s { font-size: 12px; color: var(--ink-500); }

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

/* 网格底纹 */
.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.04) 1px, transparent 1px);
  background-size: 46px 46px;
  mask-image: radial-gradient(circle at 50% 40%, #000 0%, transparent 78%);
}

/* --------------------------------------------------------------------------
   6. 业务概览 / 服务卡片
   -------------------------------------------------------------------------- */
.service-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.service-card {
  padding: 34px 28px;
  overflow: hidden;
  position: relative;
}
.service-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
  border-color: transparent;
}
.service-card__icon {
  width: 60px;
  height: 60px;
  border-radius: 14px;
  display: grid;
  place-items: center;
  margin-bottom: 22px;
  background: linear-gradient(135deg, var(--blue-50), var(--blue-100));
  color: var(--blue-600);
  transition: background var(--transition), color var(--transition);
}
.service-card__icon svg { width: 30px; height: 30px; }
.service-card:hover .service-card__icon {
  background: linear-gradient(135deg, var(--blue-600), var(--navy-800));
  color: var(--white);
}
.service-card h3 { font-size: 19px; margin-bottom: 12px; }
.service-card p { font-size: 14.5px; color: var(--ink-500); }
.service-card__more {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-top: 20px;
  font-size: 14px;
  font-weight: 600;
  color: var(--blue-600);
}
.service-card__more svg { width: 16px; height: 16px; transition: transform var(--transition); }
.service-card:hover .service-card__more svg { transform: translateX(4px); }
.service-card__tag {
  position: absolute;
  top: 20px;
  right: -34px;
  transform: rotate(45deg);
  padding: 4px 36px;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 1px;
  color: var(--white);
  background: var(--amber-500);
}

/* --------------------------------------------------------------------------
   7. 核心优势
   -------------------------------------------------------------------------- */
.why-grid {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 56px;
  align-items: center;
}

.why-list { display: grid; gap: 20px; }
.why-item {
  display: flex;
  gap: 18px;
  padding: 22px 24px;
  border-radius: var(--radius);
  background: var(--white);
  border: 1px solid var(--line);
  transition: transform var(--transition), box-shadow var(--transition);
}
.why-item:hover { transform: translateX(6px); box-shadow: var(--shadow-md); }
.why-item__num {
  font-family: var(--font-num);
  font-size: 30px;
  font-weight: 800;
  color: var(--blue-100);
  line-height: 1;
  min-width: 34px;
}
.why-item h4 { font-size: 17px; margin-bottom: 6px; }
.why-item p { font-size: 14px; color: var(--ink-500); }

.why-visual {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  background: linear-gradient(150deg, var(--navy-800), var(--navy-700));
  padding: 48px 40px;
  color: var(--white);
  box-shadow: var(--shadow-lg);
}
.why-visual::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: radial-gradient(rgba(255,255,255,0.08) 1px, transparent 1px);
  background-size: 20px 20px;
}
.why-visual h3 { color: var(--white); font-size: 24px; margin-bottom: 14px; }
.why-visual p { color: #bcd2e4; }
.why-visual__list { margin-top: 26px; display: grid; gap: 12px; position: relative; z-index: 2; }
.why-visual__list li {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 15px;
}
.why-visual__list svg { width: 20px; height: 20px; color: var(--amber-400); flex: none; }

/* --------------------------------------------------------------------------
   8. 数据统计条
   -------------------------------------------------------------------------- */
.stats-band { background: var(--navy-800); }
.stats-band__grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  padding: 56px 0;
}
.stat-block { text-align: center; color: var(--white); }
.stat-block__num {
  font-family: var(--font-num);
  font-size: clamp(34px, 4vw, 46px);
  font-weight: 800;
  line-height: 1;
  letter-spacing: 1px;
}
.stat-block__num b { color: var(--amber-400); }
.stat-block__label {
  margin-top: 12px;
  font-size: 14px;
  color: #9db6cb;
  letter-spacing: 1px;
}

/* --------------------------------------------------------------------------
   9. 服务流程
   -------------------------------------------------------------------------- */
.process-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 0;
  position: relative;
}
.process-step {
  position: relative;
  text-align: center;
  padding: 0 18px;
}
.process-step:not(:last-child)::after {
  content: "";
  position: absolute;
  top: 30px;
  right: -50%;
  width: 100%;
  height: 2px;
  background: repeating-linear-gradient(90deg, var(--blue-100) 0 6px, transparent 6px 12px);
}
.process-step__dot {
  position: relative;
  z-index: 2;
  width: 60px;
  height: 60px;
  margin: 0 auto 18px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  font-family: var(--font-num);
  font-size: 22px;
  font-weight: 800;
  color: var(--white);
  background: linear-gradient(135deg, var(--blue-600), var(--navy-800));
  box-shadow: 0 8px 20px rgba(27, 108, 184, 0.32);
}
.process-step h4 { font-size: 16px; margin-bottom: 6px; }
.process-step p { font-size: 13px; color: var(--ink-500); }

/* --------------------------------------------------------------------------
   10. 案例卡片
   -------------------------------------------------------------------------- */
.case-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.case-card { overflow: hidden; }
.case-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); }
.case-card__thumb {
  position: relative;
  height: 190px;
  display: grid;
  place-items: center;
  color: var(--white);
  background: linear-gradient(135deg, var(--navy-700), var(--blue-600));
  overflow: hidden;
}
.case-card__thumb svg { width: 72px; height: 72px; opacity: 0.9; }
.case-card__thumb::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image: linear-gradient(rgba(255,255,255,0.06) 1px, transparent 1px),
                    linear-gradient(90deg, rgba(255,255,255,0.06) 1px, transparent 1px);
  background-size: 28px 28px;
}
.case-card__cat {
  position: absolute;
  top: 14px;
  left: 14px;
  z-index: 2;
  padding: 4px 12px;
  font-size: 12px;
  font-weight: 600;
  color: var(--white);
  background: rgba(0, 0, 0, 0.32);
  border-radius: 100px;
  backdrop-filter: blur(4px);
}
.case-card__body { padding: 24px; }
.case-card__body h3 { font-size: 18px; margin-bottom: 10px; }
.case-card__body p { font-size: 14px; color: var(--ink-500); }
.case-card__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 16px;
}
.case-card__meta span {
  padding: 4px 10px;
  font-size: 12px;
  color: var(--ink-500);
  background: var(--bg-100);
  border: 1px solid var(--line);
  border-radius: 6px;
}

/* --------------------------------------------------------------------------
   11. 合作领域
   -------------------------------------------------------------------------- */
.field-grid {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 16px;
}
.field-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  padding: 28px 12px;
  text-align: center;
  border-radius: var(--radius);
  background: var(--white);
  border: 1px solid var(--line);
  font-size: 14px;
  font-weight: 600;
  color: var(--ink-700);
  transition: transform var(--transition), box-shadow var(--transition), color var(--transition);
}
.field-item:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  color: var(--blue-600);
}
.field-item svg { width: 34px; height: 34px; color: var(--blue-600); }

/* --------------------------------------------------------------------------
   12. CTA 横幅
   -------------------------------------------------------------------------- */
.cta-band {
  position: relative;
  overflow: hidden;
  background: linear-gradient(120deg, var(--navy-800), var(--blue-600));
  color: var(--white);
}
.cta-band__inner {
  position: relative;
  z-index: 2;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 52px 0;
}
.cta-band h2 { color: var(--white); font-size: clamp(22px, 3vw, 30px); }
.cta-band p { margin-top: 8px; color: #cfe0ef; }
.cta-band .btn { flex: none; }

/* --------------------------------------------------------------------------
   13. 页面头部（内页通用）
   -------------------------------------------------------------------------- */
.page-hero {
  position: relative;
  overflow: hidden;
  color: var(--white);
  background: linear-gradient(150deg, var(--navy-900), var(--navy-700));
}
.page-hero__inner { position: relative; z-index: 2; padding: 76px 0 68px; }
.page-hero .eyebrow { color: #ffd77a; }
.page-hero .eyebrow::before { background: var(--amber-500); }
.page-hero h1 { color: var(--white); font-size: clamp(30px, 4.4vw, 44px); }
.page-hero p { margin-top: 14px; max-width: 640px; color: #b9cfe2; font-size: 16px; }
.page-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  background-image:
    linear-gradient(rgba(255,255,255,0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.04) 1px, transparent 1px);
  background-size: 46px 46px;
  mask-image: linear-gradient(90deg, #000 0%, transparent 90%);
}

.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: #93adc4;
}
.breadcrumb a:hover { color: var(--amber-400); }
.breadcrumb svg { width: 14px; height: 14px; }

/* --------------------------------------------------------------------------
   14. 关于我们
   -------------------------------------------------------------------------- */
.about-grid {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 56px;
  align-items: center;
}
.about-media {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  background: linear-gradient(140deg, var(--navy-700), var(--blue-600));
  min-height: 360px;
  display: grid;
  place-items: center;
  color: rgba(255, 255, 255, 0.9);
}
.about-media svg { width: 120px; height: 120px; opacity: 0.85; }
.about-media__tag {
  position: absolute;
  left: 22px;
  bottom: 22px;
  padding: 12px 20px;
  background: var(--white);
  border-radius: 10px;
  box-shadow: var(--shadow-md);
}
.about-media__tag b { display: block; font-size: 26px; font-family: var(--font-num); color: var(--navy-800); }
.about-media__tag span { font-size: 12px; color: var(--ink-500); }

.about-text h2 { font-size: 28px; margin-bottom: 18px; }
.about-text p { color: var(--ink-500); margin-bottom: 14px; }
.about-text p strong { color: var(--ink-900); }

/* 发展历程 */
.timeline { position: relative; padding-left: 30px; }
.timeline::before {
  content: "";
  position: absolute;
  left: 8px;
  top: 4px;
  bottom: 4px;
  width: 2px;
  background: var(--blue-100);
}
.timeline__item { position: relative; padding-bottom: 32px; }
.timeline__item:last-child { padding-bottom: 0; }
.timeline__item::before {
  content: "";
  position: absolute;
  left: -30px;
  top: 6px;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--white);
  border: 4px solid var(--blue-600);
}
.timeline__year {
  font-family: var(--font-num);
  font-size: 20px;
  font-weight: 800;
  color: var(--blue-600);
}
.timeline__item h4 { font-size: 16px; margin: 4px 0 6px; }
.timeline__item p { font-size: 14px; color: var(--ink-500); }

/* 企业文化 */
.culture-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.culture-card { padding: 34px 30px; text-align: center; }
.culture-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); }
.culture-card__icon {
  width: 58px;
  height: 58px;
  margin: 0 auto 18px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: var(--blue-50);
  color: var(--blue-600);
}
.culture-card__icon svg { width: 28px; height: 28px; }
.culture-card h3 { font-size: 18px; margin-bottom: 10px; }
.culture-card p { font-size: 14px; color: var(--ink-500); }

/* 资质荣誉 */
.cert-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}
.cert-card {
  padding: 26px;
  display: flex;
  align-items: center;
  gap: 16px;
  border-radius: var(--radius);
  background: var(--white);
  border: 1px solid var(--line);
  transition: transform var(--transition), box-shadow var(--transition);
}
.cert-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); }
.cert-card__icon {
  width: 48px;
  height: 48px;
  flex: none;
  border-radius: 10px;
  display: grid;
  place-items: center;
  background: var(--amber-50);
  color: var(--amber-500);
}
.cert-card__icon svg { width: 26px; height: 26px; }
.cert-card b { display: block; font-size: 15px; color: var(--ink-900); }
.cert-card span { font-size: 13px; color: var(--ink-500); }

/* --------------------------------------------------------------------------
   15. 业务范围
   -------------------------------------------------------------------------- */
.service-detail {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}
.service-detail__card { padding: 36px 32px; }
.service-detail__card:hover { transform: translateY(-5px); box-shadow: var(--shadow-lg); }
.service-detail__head {
  display: flex;
  align-items: center;
  gap: 18px;
  margin-bottom: 18px;
}
.service-detail__icon {
  width: 62px;
  height: 62px;
  flex: none;
  border-radius: 14px;
  display: grid;
  place-items: center;
  background: linear-gradient(135deg, var(--blue-600), var(--navy-800));
  color: var(--white);
}
.service-detail__icon svg { width: 30px; height: 30px; }
.service-detail__head h3 { font-size: 21px; }
.service-detail__head .en {
  font-size: 12px;
  letter-spacing: 1.5px;
  color: var(--steel-400);
  text-transform: uppercase;
}
.service-detail__card > p { font-size: 14.5px; color: var(--ink-500); margin-bottom: 20px; }
.service-detail__list { display: grid; gap: 10px; }
.service-detail__list li {
  display: flex;
  gap: 10px;
  font-size: 14.5px;
  color: var(--ink-700);
}
.service-detail__list svg { width: 18px; height: 18px; color: var(--amber-500); flex: none; margin-top: 2px; }
.service-detail__tags { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 20px; }
.service-detail__tags span {
  padding: 5px 12px;
  font-size: 12.5px;
  color: var(--blue-600);
  background: var(--blue-50);
  border-radius: 100px;
}

/* --------------------------------------------------------------------------
   16. 成功案例页
   -------------------------------------------------------------------------- */
.case-filter {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  margin-bottom: 40px;
}
.case-filter button {
  padding: 9px 20px;
  font-size: 14px;
  font-weight: 600;
  color: var(--ink-700);
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 100px;
  transition: all var(--transition);
}
.case-filter button:hover { border-color: var(--blue-600); color: var(--blue-600); }
.case-filter button.active {
  background: var(--navy-800);
  border-color: var(--navy-800);
  color: var(--white);
}
.case-list { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.case-list .case-card { display: none; }
.case-list .case-card.show { display: block; }

/* --------------------------------------------------------------------------
   17. 联系我们
   -------------------------------------------------------------------------- */
.contact-grid {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 28px;
}
.contact-card {
  display: flex;
  gap: 18px;
  padding: 24px;
  border-radius: var(--radius);
  background: var(--white);
  border: 1px solid var(--line);
}
.contact-card__icon {
  width: 50px;
  height: 50px;
  flex: none;
  border-radius: 12px;
  display: grid;
  place-items: center;
  background: var(--blue-50);
  color: var(--blue-600);
}
.contact-card__icon svg { width: 24px; height: 24px; }
.contact-card h4 { font-size: 15px; color: var(--ink-500); font-weight: 500; margin-bottom: 4px; }
.contact-card b { font-size: 17px; color: var(--ink-900); }
.contact-card p { font-size: 14px; color: var(--ink-500); margin-top: 2px; }

.form-card { padding: 38px 36px; }
.form-card h3 { font-size: 20px; margin-bottom: 6px; }
.form-card > p { font-size: 14px; color: var(--ink-500); margin-bottom: 24px; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.form-field { margin-bottom: 18px; }
.form-field label {
  display: block;
  margin-bottom: 7px;
  font-size: 14px;
  font-weight: 600;
  color: var(--ink-900);
}
.form-field label em { color: #e5484d; font-style: normal; margin-left: 3px; }
.form-field input,
.form-field textarea,
.form-field select {
  width: 100%;
  padding: 12px 14px;
  font-size: 15px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--bg-50);
  transition: border-color var(--transition), box-shadow var(--transition);
}
.form-field input:focus,
.form-field textarea:focus,
.form-field select:focus {
  border-color: var(--blue-600);
  box-shadow: 0 0 0 3px rgba(27, 108, 184, 0.12);
  background: var(--white);
}
.form-field textarea { resize: vertical; min-height: 120px; }
.form-hint { margin-top: -8px; margin-bottom: 16px; font-size: 12.5px; color: var(--steel-400); }
.form-msg { display: none; margin-top: 16px; padding: 13px 16px; border-radius: 8px; font-size: 14px; }
.form-msg.ok { display: block; background: #ecfdf3; color: #1a7f46; border: 1px solid #b7e6c8; }
.form-msg.err { display: block; background: #fdf0f0; color: #c0343a; border: 1px solid #f3c8ca; }

.map-placeholder {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  background: linear-gradient(135deg, #dbe7f1, #c4d6e6);
  min-height: 320px;
  display: grid;
  place-items: center;
}
.map-placeholder__inner { text-align: center; color: var(--ink-500); }
.map-placeholder__inner svg { width: 60px; height: 60px; color: var(--blue-600); margin: 0 auto 14px; }
.map-placeholder__inner p { font-size: 14px; }

/* --------------------------------------------------------------------------
   18. 页脚
   -------------------------------------------------------------------------- */
.site-footer {
  background: var(--navy-900);
  color: #9db6cb;
}
.site-footer__top {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1.2fr;
  gap: 40px;
  padding: 64px 0 48px;
}
.footer-brand .brand__name { color: var(--white); }
.footer-brand .brand__sub { color: #64819c; }
.footer-brand p { margin-top: 18px; font-size: 14px; line-height: 1.8; max-width: 300px; }
.footer-col h4 {
  color: var(--white);
  font-size: 15px;
  letter-spacing: 1px;
  margin-bottom: 20px;
}
.footer-col ul { display: grid; gap: 12px; }
.footer-col ul a { font-size: 14px; color: #9db6cb; transition: color var(--transition); }
.footer-col ul a:hover { color: var(--amber-400); }
.footer-contact li {
  display: flex;
  gap: 10px;
  font-size: 14px;
  line-height: 1.6;
}
.footer-contact svg { width: 17px; height: 17px; color: var(--amber-400); flex: none; margin-top: 4px; }
.site-footer__bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding: 22px 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  font-size: 13px;
  color: #64819c;
}
.site-footer__bottom a { color: #8aa4bc; }
.site-footer__bottom a:hover { color: var(--amber-400); }

/* 回到顶部 */
.to-top {
  position: fixed;
  right: 26px;
  bottom: 26px;
  z-index: 90;
  width: 46px;
  height: 46px;
  border-radius: 12px;
  display: grid;
  place-items: center;
  color: var(--white);
  background: var(--navy-800);
  box-shadow: var(--shadow-lg);
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: all var(--transition);
}
.to-top.show { opacity: 1; visibility: visible; transform: none; }
.to-top:hover { background: var(--blue-600); }
.to-top svg { width: 20px; height: 20px; }

/* --------------------------------------------------------------------------
   19. 响应式
   -------------------------------------------------------------------------- */
@media (max-width: 1024px) {
  .service-grid, .case-grid, .case-list { grid-template-columns: repeat(2, 1fr); }
  .field-grid { grid-template-columns: repeat(3, 1fr); }
  .process-grid { grid-template-columns: repeat(3, 1fr); gap: 28px 0; }
  .process-step:not(:last-child)::after { display: none; }
  .why-grid, .about-grid { grid-template-columns: 1fr; gap: 36px; }
  .contact-grid { grid-template-columns: 1fr; }
  .site-footer__top { grid-template-columns: 1fr 1fr; }
  .hero__grid { grid-template-columns: 1fr; gap: 40px; padding: 72px 0; }
  .hero__visual { max-width: 480px; margin: 0 auto; }
  .cert-grid { grid-template-columns: repeat(2, 1fr); }
  .stats-band__grid { grid-template-columns: repeat(2, 1fr); gap: 36px; }
}

@media (max-width: 768px) {
  :root { --header-h: 64px; }
  .section { padding: 64px 0; }

  /* 手机端品牌名缩短显示（不折行） */
  .site-header__inner { gap: 14px; }
  .site-header .brand__name { font-size: 0; white-space: nowrap; }
  .site-header .brand__name::after { content: "北京龙超智业"; font-size: 16px; white-space: nowrap; }

  .main-nav {
    position: fixed;
    inset: var(--header-h) 0 0 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 16px 24px 32px;
    background: var(--white);
    border-top: 1px solid var(--line);
    transform: translateX(100%);
    transition: transform var(--transition);
    overflow-y: auto;
  }
  .main-nav.open { transform: translateX(0); }
  .main-nav a { padding: 14px 12px; font-size: 16px; border-bottom: 1px solid var(--bg-100); }
  .main-nav a.active::after { display: none; }
  .main-nav a.active { background: var(--blue-50); border-radius: 8px; }
  .nav-toggle { display: grid; }
  .header-cta .btn { display: none; }
  .header-phone { font-size: 14px; }

  .service-grid, .case-grid, .case-list,
  .service-detail, .culture-grid, .cert-grid { grid-template-columns: 1fr; }
  .field-grid { grid-template-columns: repeat(2, 1fr); }
  .stats-band__grid { grid-template-columns: repeat(2, 1fr); }
  .process-grid { grid-template-columns: 1fr 1fr; }
  .form-row { grid-template-columns: 1fr; }
  .site-footer__top { grid-template-columns: 1fr; gap: 32px; }
  .cta-band__inner { flex-direction: column; text-align: center; }
  .hero__stats { flex-wrap: wrap; gap: 24px; }
  .hero__badge--tl { left: 0; }
  .hero__badge--br { right: 0; }
}

@media (max-width: 480px) {
  .container { padding: 0 18px; }
  .hero__actions { flex-direction: column; }
  .hero__actions .btn { width: 100%; }
  .field-grid { grid-template-columns: 1fr 1fr; }
  .stats-band__grid { grid-template-columns: 1fr 1fr; }
}