/* ============================================================
   常州昆超电气有限公司 - 科技企业官网 v2
   风格: 简洁高端 · 蓝白基调 · 呼吸感
   ============================================================ */

:root {
  --primary: #0f2b4a;
  --primary-light: #1a4a7a;
  --accent: #0077ff;
  --accent-light: #4a9eff;
  --accent-subtle: rgba(0,119,255,.06);
  --bg: #ffffff;
  --bg-alt: #f6f8fc;
  --bg-card: #ffffff;
  --text: #1a2332;
  --text-body: #4a5568;
  --text-dim: #8896a8;
  --border: #e8edf4;
  --border-light: #f0f4fa;
  --shadow-sm: 0 1px 3px rgba(0,0,0,.04);
  --shadow-md: 0 4px 20px rgba(0,0,0,.06);
  --shadow-lg: 0 12px 40px rgba(0,0,0,.08);
  --radius: 12px;
  --radius-lg: 20px;
}

* { margin:0;padding:0;box-sizing:border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: -apple-system, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

/* ─── Header ─── */
header {
  position: fixed; top:0; left:0; right:0; z-index:1000;
  background: rgba(255,255,255,.92);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-light);
  transition: all .3s;
}
header.scrolled { border-bottom-color: var(--border); box-shadow: var(--shadow-sm); }
.nav-inner {
  max-width: 1100px; margin:0 auto;
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 24px; height: 72px;
}
.logo {
  display: flex; align-items: center;
  text-decoration: none;
}
.logo-img { height: 36px; width: auto; display: block; }

.nav-links { display: flex; gap: 2px; }
.nav-links a {
  padding: 8px 18px; border-radius: 8px;
  color: var(--text-body); text-decoration: none;
  font-size: 14px; font-weight: 500;
  transition: all .2s;
}
.nav-links a:hover { color: var(--accent); background: var(--accent-subtle); }
.nav-links a.active { color: var(--accent); font-weight: 600; background: var(--accent-subtle); }
.nav-toggle { display: none; background: none; border: none; font-size: 22px; cursor: pointer; padding: 8px; color: var(--text); }

/* ─── Hero ─── */
.hero {
  padding: 160px 24px 100px;
  background: linear-gradient(180deg, #f0f6ff 0%, #fff 60%);
  position: relative; overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute; top: -50%; right: -20%;
  width: 800px; height: 800px;
  background: radial-gradient(circle, rgba(0,119,255,.04) 0%, transparent 70%);
  pointer-events: none;
}
.hero-inner { max-width: 1100px; margin: 0 auto; position: relative; }
.hero-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 60px; align-items: center; }
.hero-tag {
  display: inline-block;
  padding: 4px 16px;
  background: var(--accent-subtle);
  border-radius: 50px;
  font-size: 13px; font-weight: 600;
  color: var(--accent);
  letter-spacing: .5px;
  margin-bottom: 20px;
}
.hero h1 {
  font-size: clamp(32px, 4vw, 48px);
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 20px;
  color: var(--primary);
}
.hero h1 .hl { color: var(--accent); }
.hero p {
  font-size: 17px;
  color: var(--text-body);
  line-height: 1.8;
  margin-bottom: 32px;
  max-width: 480px;
}
.hero .btn-group { display: flex; gap: 12px; }

.btn {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 14px 28px; border-radius: 8px;
  font-size: 15px; font-weight: 600; text-decoration: none; cursor: pointer; border: none;
  transition: all .25s;
}
.btn-primary {
  background: var(--accent); color: #fff;
  box-shadow: 0 4px 14px rgba(0,119,255,.25);
}
.btn-primary:hover {
  background: #0066e6;
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(0,119,255,.35);
}
.btn-outline {
  background: transparent; color: var(--text);
  border: 1.5px solid var(--border);
}
.btn-outline:hover { border-color: var(--accent); color: var(--accent); }

.hero-illustration {
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 12px;
  overflow: hidden;
  min-height: 320px;
  background: linear-gradient(135deg, #e8f0fe, #f0f4ff);
}
.hero-illustration img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: 12px;
}

/* ─── Sections ─── */
section { padding: 100px 24px; }
.section-inner { max-width: 1100px; margin: 0 auto; }
.section-header {
  text-align: center; margin-bottom: 56px;
}
.section-label {
  display: inline-block;
  font-size: 12px; font-weight: 700;
  color: var(--accent); letter-spacing: 2px; text-transform: uppercase;
  margin-bottom: 12px;
}
.section-title {
  font-size: clamp(26px, 3vw, 36px);
  font-weight: 800;
  color: var(--primary);
  margin-bottom: 12px;
}
.section-subtitle {
  font-size: 16px;
  color: var(--text-body);
  max-width: 560px;
  margin: 0 auto;
}

/* ─── Core Business ─── */
.services-grid {
  display: grid; grid-template-columns: repeat(2,1fr); gap: 24px;
}
.service-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 40px 28px;
  transition: all .3s;
}
.service-card:hover {
  border-color: var(--accent);
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
}
.service-icon {
  width: 52px; height: 52px;
  background: var(--accent-subtle);
  border-radius: 12px;
  display: flex; align-items: center; justify-content: center;
  font-size: 24px; margin-bottom: 20px;
}
.service-card h3 { font-size: 18px; font-weight: 700; margin-bottom: 4px; color: var(--primary); }
.service-tag {
  display: inline-block; padding: 2px 10px;
  background: var(--accent-subtle); border-radius: 4px;
  font-size: 12px; font-weight: 600; color: var(--accent);
  margin-bottom: 14px;
}
.service-card p { font-size: 14px; color: var(--text-body); line-height: 1.8; }

/* ─── Advantages (why us) ─── */
.section-alt { background: var(--bg-alt); }
.advantages-grid {
  display: grid; grid-template-columns: repeat(2,1fr); gap: 20px;
}
.advantage-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  display: flex; gap: 16px;
  transition: all .3s;
}
.advantage-card:hover { border-color: var(--accent); box-shadow: var(--shadow-sm); }
.advantage-icon {
  width: 44px; height: 44px; min-width:44px;
  background: var(--accent-subtle);
  border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  font-size: 18px;
}
.advantage-card h4 { font-size: 16px; font-weight: 700; margin-bottom: 4px; color: var(--primary); }
.advantage-card p { font-size: 14px; color: var(--text-body); line-height: 1.7; }

/* ─── Partners ─── */
.partners-wrap {
  display: flex; flex-wrap: wrap; justify-content: center; gap: 12px;
}
.partner-item {
  padding: 10px 24px;
  background: var(--bg-alt);
  border: 1px solid var(--border-light);
  border-radius: 50px;
  font-size: 14px; font-weight: 500; color: var(--text-body);
  transition: all .2s;
}
.partner-item:hover { border-color: var(--accent); color: var(--accent); background: var(--accent-subtle); }

/* ─── CTA ─── */
.cta-section {
  background: var(--bg-alt);
  text-align: center;
  border-top: 1px solid var(--border-light);
}
.cta-section h2 { font-size: clamp(22px,2.5vw,30px); font-weight: 800; color: var(--primary); margin-bottom: 8px; }
.cta-section p { color: var(--text-body); font-size: 16px; margin-bottom: 28px; }

/* ═══════════════════════════
   产品页
   ═══════════════════════════ */
.page-hero {
  padding: 140px 24px 60px;
  background: linear-gradient(180deg, #f0f6ff, #fff);
  text-align: center;
}
.page-hero h1 { font-size: clamp(28px,3.5vw,40px); font-weight: 800; color: var(--primary); margin-bottom: 8px; }
.page-hero p { color: var(--text-body); font-size: 16px; }

.products-grid {
  display: grid; grid-template-columns: repeat(3,1fr); gap: 24px;
}
.product-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: all .3s;
}
.product-card:hover { border-color: var(--accent); box-shadow: var(--shadow-md); transform: translateY(-4px); }
.product-icon {
  height: 160px;
  display: flex; align-items: center; justify-content: center;
  overflow: hidden;
  background: #0f172a;
}
.product-icon img { width: 100%; height: 100%; object-fit: cover; }
.product-body { padding: 24px; }
.product-body h3 { font-size: 17px; font-weight: 700; color: var(--primary); margin-bottom: 2px; }
.product-tag { display: inline-block; padding: 2px 10px; background: var(--accent-subtle); border-radius: 4px; font-size: 12px; color: var(--accent); font-weight: 600; margin-bottom: 12px; }
.product-body ul { list-style: none; padding: 0; }
.product-body ul li { padding: 4px 0; font-size: 14px; color: var(--text-body); position: relative; padding-left: 16px; }
.product-body ul li::before { content: '✓'; position: absolute; left:0; color: var(--accent); font-weight: 700; }
.product-cta-box {
  text-align: center; margin-top: 60px; padding: 40px;
  background: var(--bg-alt); border: 1px solid var(--border-light);
  border-radius: var(--radius);
}

/* ═══════════════════════════
   解决方案
   ═══════════════════════════ */
.solutions-list { display: flex; flex-direction: column; gap: 20px; }
.solution-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 36px;
  display: grid; grid-template-columns: 64px 1fr; gap: 28px;
  transition: all .3s;
}
.solution-item:hover { border-color: var(--accent); box-shadow: var(--shadow-sm); }
.solution-icon {
  width: 64px; height: 64px;
  background: var(--accent-subtle);
  border-radius: 14px;
  display: flex; align-items: center; justify-content: center;
  font-size: 28px;
}
.solution-text h3 { font-size: 18px; font-weight: 700; color: var(--primary); margin-bottom: 12px; }
.solution-text ul { list-style: none; padding: 0; columns: 2; column-gap: 32px; }
.solution-text ul li { padding: 4px 0; font-size: 14px; color: var(--text-body); padding-left: 16px; position: relative; break-inside: avoid; }
.solution-text ul li::before { content: '▸'; position: absolute; left:0; color: var(--accent); }
.solution-cta-text { color: var(--accent); font-weight: 600; margin-top: 14px; font-size: 14px; }

/* ═══════════════════════════
   关于
   ═══════════════════════════ */
.about-wrap { max-width: 760px; margin: 0 auto; }
.about-text { font-size: 15px; line-height: 2; color: var(--text-body); }
.about-text p { margin-bottom: 20px; }
.stats-row {
  display: grid; grid-template-columns: repeat(3,1fr); gap: 16px;
  margin: 48px 0;
}
.stat-item {
  text-align: center; padding: 28px 16px;
  background: var(--bg-alt); border: 1px solid var(--border-light);
  border-radius: var(--radius);
}
.stat-num { font-size: 36px; font-weight: 800; color: var(--accent); }
.stat-label { font-size: 14px; color: var(--text-body); margin-top: 2px; }
.about-footer-card {
  text-align: center; margin-top: 32px; padding: 36px;
  background: var(--bg-alt); border: 1px solid var(--border-light);
  border-radius: var(--radius);
}
.about-footer-card p { color: var(--text-body); line-height: 2; }

/* ═══════════════════════════
   联系
   ═══════════════════════════ */
.contact-grid {
  display: grid; grid-template-columns: 1fr 1.2fr; gap: 48px;
}
.contact-item {
  display: flex; gap: 14px; margin-bottom: 24px;
}
.contact-icon {
  width: 44px; height: 44px; min-width:44px;
  background: var(--accent-subtle);
  border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  font-size: 18px;
}
.contact-item h4 { font-size: 13px; font-weight: 600; color: var(--text-dim); margin-bottom: 1px; }
.contact-item p { font-size: 15px; color: var(--text); }
.contact-form-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 36px;
}
.contact-form-card h3 { font-size: 18px; font-weight: 700; color: var(--primary); margin-bottom: 20px; }
.contact-form label { display: block; margin-bottom: 4px; font-size: 13px; font-weight: 600; color: var(--text-body); }
.contact-form input,
.contact-form textarea {
  width: 100%; padding: 12px 16px;
  border: 1.5px solid var(--border);
  border-radius: 8px;
  font-size: 15px; font-family: inherit;
  color: var(--text); background: var(--bg);
  margin-bottom: 16px;
  transition: border-color .2s;
}
.contact-form input:focus,
.contact-form textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(0,119,255,.08);
}
.contact-form textarea { height: 120px; resize: vertical; }
.contact-form .btn { width: 100%; justify-content: center; }

/* ─── Toast ─── */
.toast-msg {
  position: fixed; bottom: 32px; left: 50%; transform: translateX(-50%);
  background: var(--primary); color: #fff;
  padding: 12px 24px; border-radius: 8px;
  font-size: 14px; z-index: 9999;
  box-shadow: var(--shadow-lg);
  transition: opacity .3s; opacity: 0;
}

/* ═══════════════════════════
   页脚
   ═══════════════════════════ */
footer {
  background: var(--primary); color: rgba(255,255,255,.7);
  padding: 48px 24px 28px;
  margin-top: 0;
}
.footer-inner { max-width: 1100px; margin: 0 auto; display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 48px; }
footer h5 { font-size: 13px; font-weight: 700; color: #fff; margin-bottom: 14px; letter-spacing: .5px; text-transform: uppercase; }
footer a { color: rgba(255,255,255,.6); text-decoration: none; display: block; margin-bottom: 6px; font-size: 14px; transition: color .2s; }
footer a:hover { color: #fff; }
.footer-desc { font-size: 14px; line-height: 1.8; color: rgba(255,255,255,.5); }
.footer-contact { font-size: 14px; line-height: 1.8; color: rgba(255,255,255,.5); }
.footer-bottom {
  max-width: 1100px; margin: 32px auto 0;
  padding-top: 20px; border-top: 1px solid rgba(255,255,255,.1);
  text-align: center; font-size: 13px; color: rgba(255,255,255,.4);
}

/* ═══════════════════════════
   隐藏页
   ═══════════════════════════ */
.hidden-state {
  text-align: center; padding: 60px 20px;
}
.hidden-state h2 { font-size: 20px; color: var(--text-body); margin-bottom: 8px; font-weight: 600; }
.hidden-state p { color: var(--text-dim); }

/* ═══════════════════════════
   响应式
   ═══════════════════════════ */
@media (max-width: 768px) {
  .nav-links {
    display: none; position: absolute; top:72px; left:0; right:0;
    background: rgba(255,255,255,.98); flex-direction: column;
    padding: 16px; border-bottom: 1px solid var(--border);
    backdrop-filter: blur(16px);
  }
  .nav-links.open { display: flex; }
  .nav-toggle { display: block; }
  .hero-grid { grid-template-columns: 1fr; gap: 40px; }
  .hero-illustration { min-height: 240px; }
  .hero { padding: 120px 20px 60px; }
  .services-grid { grid-template-columns: 1fr; }
  .advantages-grid { grid-template-columns: 1fr; }
  .products-grid { grid-template-columns: 1fr; }
  .solution-item { grid-template-columns: 1fr; gap: 16px; }
  .solution-text ul { columns: 1; }
  .contact-grid { grid-template-columns: 1fr; }
  .stats-row { grid-template-columns: 1fr; }
  .footer-inner { grid-template-columns: 1fr; gap: 32px; }
  section { padding: 60px 20px; }
}