/* ============================================================
   品粤 数字孪生安全监控 — 全局样式
   主色: #0A1628 (深蓝)  高亮: #00D4FF (青蓝)  告警: #FF4757 (橙红)
   ============================================================ */

:root {
  --bg-deep: #0A1628;
  --bg-dark: #0F1F3A;
  --bg-card: #132744;
  --bg-card-hover: #1A3358;
  --cyan: #00D4FF;
  --cyan-dim: rgba(0, 212, 255, 0.15);
  --red: #FF4757;
  --red-dim: rgba(255, 71, 87, 0.12);
  --text: #E0E8F0;
  --text-dim: #8899B4;
  --text-muted: #5A6E8A;
  --border: rgba(0, 212, 255, 0.1);
  --border-glow: rgba(0, 212, 255, 0.3);
  --radius: 8px;
  --radius-lg: 14px;
  --font-cn: 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', 'WenQuanYi Micro Hei', sans-serif;
  --font-en: 'Segoe UI', system-ui, -apple-system, 'Helvetica Neue', Arial, sans-serif;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-cn);
  background: var(--bg-deep);
  color: var(--text);
  line-height: 1.7;
  overflow-x: hidden;
}

/* ── Navigation ── */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  background: rgba(10, 22, 40, 0.92);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
  padding: 0 40px; height: 64px;
  display: flex; align-items: center; justify-content: space-between;
  transition: all 0.3s;
}
.nav.scrolled { background: rgba(10, 22, 40, 0.98); box-shadow: 0 4px 40px rgba(0,0,0,0.4); }

.logo {
  display: flex; align-items: center; gap: 10px;
  font-size: 1.25rem; font-weight: 700; color: var(--text);
  text-decoration: none;
}
.logo-icon {
  width: 36px; height: 36px; border-radius: 8px;
  background: linear-gradient(135deg, var(--cyan), #0088CC);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.1rem; color: #fff; font-weight: 900;
}

.nav-links { display: flex; gap: 32px; list-style: none; align-items: center; }
.nav-links a {
  color: var(--text-dim); text-decoration: none; font-size: 0.9rem;
  font-weight: 500; transition: color 0.25s; position: relative;
}
.nav-links a:hover, .nav-links a.active { color: var(--cyan); }
.nav-links a::after {
  content: ''; position: absolute; bottom: -4px; left: 0; width: 0; height: 2px;
  background: var(--cyan); transition: width 0.3s;
}
.nav-links a:hover::after, .nav-links a.active::after { width: 100%; }

.btn-nav {
  padding: 8px 22px; border-radius: 20px; font-size: 0.85rem;
  font-weight: 600; text-decoration: none; transition: all 0.3s;
}
.btn-demo {
  background: linear-gradient(135deg, var(--cyan), #0088CC);
  color: #fff; border: none;
}
.btn-demo:hover { transform: translateY(-1px); box-shadow: 0 6px 24px rgba(0,212,255,0.3); }

/* ── Hero Section ── */
.hero {
  position: relative; min-height: 100vh;
  display: flex; align-items: center; justify-content: center;
  overflow: hidden;
}
#hero-canvas {
  position: absolute; top: 0; left: 0; width: 100%; height: 100%; z-index: 0;
}
.hero-overlay {
  position: absolute; top: 0; left: 0; right: 0; bottom: 0;
  background: radial-gradient(ellipse at center, transparent 30%, rgba(10,22,40,0.7) 70%, var(--bg-deep) 100%);
  z-index: 1;
}
.hero-content {
  position: relative; z-index: 2; text-align: center; max-width: 800px; padding: 0 20px;
}
.hero-badge {
  display: inline-block; padding: 6px 20px; border-radius: 20px;
  background: var(--cyan-dim); border: 1px solid var(--border-glow);
  color: var(--cyan); font-size: 0.85rem; font-weight: 600;
  margin-bottom: 28px; letter-spacing: 2px;
}
.hero-content h1 {
  font-size: clamp(2rem, 5vw, 3.2rem); font-weight: 800;
  line-height: 1.3; margin-bottom: 20px;
}
.hero-content h1 .highlight {
  background: linear-gradient(135deg, var(--cyan), #00A8FF);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
}
.hero-content p {
  font-size: 1.15rem; color: var(--text-dim); margin-bottom: 36px;
  line-height: 1.8;
}
.hero-buttons { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.btn {
  display: inline-block; padding: 14px 36px; border-radius: 28px;
  font-size: 1rem; font-weight: 600; text-decoration: none;
  transition: all 0.3s; cursor: pointer; border: none;
}
.btn-primary {
  background: linear-gradient(135deg, var(--cyan), #0088CC);
  color: #fff;
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 32px rgba(0,212,255,0.35); }
.btn-outline {
  background: transparent; color: var(--cyan);
  border: 1.5px solid var(--border-glow);
}
.btn-outline:hover { background: var(--cyan-dim); transform: translateY(-2px); }

/* ── Section Common ── */
.section { padding: 100px 40px; max-width: 1200px; margin: 0 auto; }
.section-header { text-align: center; margin-bottom: 64px; }
.section-tag {
  display: inline-block; padding: 4px 16px; border-radius: 12px;
  background: var(--cyan-dim); color: var(--cyan);
  font-size: 0.8rem; font-weight: 600; letter-spacing: 1px;
  margin-bottom: 16px;
}
.section-header h2 { font-size: 2.2rem; font-weight: 800; margin-bottom: 12px; }
.section-header p { color: var(--text-dim); font-size: 1.05rem; max-width: 600px; margin: 0 auto; }

/* ── Solution Cards ── */
.cards-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(340px, 1fr)); gap: 28px; }
.card {
  background: var(--bg-card); border-radius: var(--radius-lg);
  border: 1px solid var(--border); padding: 36px 30px;
  transition: all 0.35s; position: relative; overflow: hidden;
}
.card::before {
  content: ''; position: absolute; top: 0; left: 0; right: 0; height: 3px;
  background: linear-gradient(90deg, var(--cyan), transparent);
  opacity: 0; transition: opacity 0.35s;
}
.card:hover {
  background: var(--bg-card-hover); border-color: var(--border-glow);
  transform: translateY(-4px); box-shadow: 0 12px 48px rgba(0,0,0,0.3);
}
.card:hover::before { opacity: 1; }

.card-icon { font-size: 2.5rem; margin-bottom: 18px; }
.card h3 { font-size: 1.3rem; font-weight: 700; margin-bottom: 10px; }
.card p { color: var(--text-dim); font-size: 0.92rem; line-height: 1.7; margin-bottom: 16px; }
.card-features { list-style: none; margin-bottom: 20px; }
.card-features li {
  color: var(--text-dim); font-size: 0.88rem; padding: 5px 0;
  padding-left: 20px; position: relative;
}
.card-features li::before {
  content: '▸'; position: absolute; left: 0; color: var(--cyan);
}
.card-link {
  color: var(--cyan); text-decoration: none; font-weight: 600;
  font-size: 0.9rem; display: inline-flex; align-items: center; gap: 6px;
  transition: gap 0.3s;
}
.card-link:hover { gap: 12px; }

/* ── Value Props (icon row) ── */
.value-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 32px; }
.value-item { text-align: center; padding: 30px 20px; }
.value-icon { font-size: 2.8rem; margin-bottom: 14px; }
.value-item h4 { font-size: 1.05rem; font-weight: 700; margin-bottom: 8px; }
.value-item p { color: var(--text-dim); font-size: 0.88rem; }

/* ── Stats ── */
.stats-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 24px; }
.stat-card {
  background: var(--bg-card); border-radius: var(--radius-lg);
  border: 1px solid var(--border); padding: 32px 20px; text-align: center;
}
.stat-number {
  font-size: 2.8rem; font-weight: 800;
  background: linear-gradient(135deg, var(--cyan), #00A8FF);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
}
.stat-label { color: var(--text-dim); font-size: 0.9rem; margin-top: 6px; }

/* ── Case cards ── */
.case-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(380px, 1fr)); gap: 32px; }
.case-card {
  background: var(--bg-card); border-radius: var(--radius-lg);
  border: 1px solid var(--border); overflow: hidden;
  transition: all 0.35s;
}
.case-card:hover { border-color: var(--border-glow); transform: translateY(-4px); }
.case-img {
  height: 200px; background: linear-gradient(135deg, #0F1F3A, #162A4A);
  display: flex; align-items: center; justify-content: center; font-size: 3rem;
}
.case-body { padding: 28px; }
.case-body h3 { font-size: 1.2rem; margin-bottom: 8px; }
.case-meta { color: var(--text-muted); font-size: 0.82rem; margin-bottom: 12px; }
.case-stats { display: flex; gap: 20px; margin: 16px 0; }
.case-stat { text-align: center; }
.case-stat-num { font-size: 1.3rem; font-weight: 700; color: var(--cyan); }
.case-stat-label { font-size: 0.75rem; color: var(--text-muted); }

/* ── Tech stack pills ── */
.tech-section { margin: 20px 0; }
.tech-section h4 { font-size: 0.9rem; color: var(--cyan); margin-bottom: 10px; }
.tech-pills { display: flex; flex-wrap: wrap; gap: 8px; }
.tech-pill {
  padding: 4px 14px; border-radius: 14px; font-size: 0.8rem;
  background: var(--cyan-dim); color: var(--cyan);
  border: 1px solid rgba(0,212,255,0.15); font-weight: 500;
}

/* ── CTA Banner ── */
.cta-banner {
  background: linear-gradient(135deg, #0D2340, #102848);
  border-radius: var(--radius-lg); padding: 60px 40px;
  text-align: center; border: 1px solid var(--border);
  position: relative; overflow: hidden;
}
.cta-banner::before {
  content: ''; position: absolute; top: -50%; left: -50%; width: 200%; height: 200%;
  background: radial-gradient(circle at 70% 30%, rgba(0,212,255,0.06), transparent 60%);
}
.cta-banner h3 { font-size: 1.8rem; font-weight: 800; margin-bottom: 14px; position: relative; }
.cta-banner p { color: var(--text-dim); margin-bottom: 28px; position: relative; }

/* ── Footer ── */
.footer {
  background: var(--bg-dark); border-top: 1px solid var(--border);
  padding: 60px 40px 30px;
}
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; max-width: 1200px; margin: 0 auto 40px; }
.footer-col h4 { font-size: 0.95rem; font-weight: 700; margin-bottom: 18px; color: var(--text); }
.footer-col a { display: block; color: var(--text-dim); text-decoration: none; font-size: 0.85rem; padding: 4px 0; transition: color 0.2s; }
.footer-col a:hover { color: var(--cyan); }
.footer-bottom {
  max-width: 1200px; margin: 0 auto; padding-top: 24px;
  border-top: 1px solid var(--border); text-align: center;
  color: var(--text-muted); font-size: 0.8rem;
}

/* ── Page Banner (inner pages) ── */
.page-banner {
  padding: 120px 40px 60px; text-align: center;
  background: radial-gradient(ellipse at 50% 0%, rgba(0,212,255,0.08), transparent 60%);
}
.page-banner h1 { font-size: 2.5rem; font-weight: 800; margin-bottom: 12px; }
.page-banner p { color: var(--text-dim); font-size: 1.05rem; }

/* ── Feature block (solutions detail) ── */
.feature-block {
  display: grid; grid-template-columns: 1fr 1fr; gap: 60px;
  align-items: center; padding: 60px 0; border-bottom: 1px solid var(--border);
}
.feature-block.reverse { direction: rtl; }
.feature-block.reverse .feature-text { direction: ltr; }
.feature-text h3 { font-size: 1.5rem; font-weight: 700; margin-bottom: 14px; }
.feature-text p { color: var(--text-dim); margin-bottom: 12px; line-height: 1.8; }
.feature-visual {
  background: var(--bg-card); border-radius: var(--radius-lg);
  border: 1px solid var(--border); min-height: 260px;
  display: flex; align-items: center; justify-content: center;
  font-size: 5rem; direction: ltr;
}

/* ── Security highlight box ── */
.security-box {
  background: var(--red-dim); border: 1px solid rgba(255,71,87,0.2);
  border-radius: var(--radius-lg); padding: 30px; margin: 20px 0;
}
.security-box h4 { color: var(--red); font-size: 1.1rem; margin-bottom: 12px; }
.security-box p { color: var(--text-dim); font-size: 0.9rem; }

/* ── Alert timeline ── */
.timeline { position: relative; padding-left: 30px; }
.timeline::before { content: ''; position: absolute; left: 8px; top: 0; bottom: 0; width: 2px; background: var(--border); }
.timeline-item { position: relative; margin-bottom: 24px; padding-left: 20px; }
.timeline-item::before {
  content: ''; position: absolute; left: -26px; top: 6px;
  width: 10px; height: 10px; border-radius: 50%; background: var(--cyan);
}
.timeline-time { font-size: 0.78rem; color: var(--text-muted); }
.timeline-text { font-size: 0.92rem; color: var(--text-dim); }

/* ── Contact form (if we add one) ── */
.contact-form { max-width: 560px; margin: 0 auto; }
.form-group { margin-bottom: 20px; }
.form-group label { display: block; font-size: 0.88rem; color: var(--text-dim); margin-bottom: 6px; }
.form-group input, .form-group textarea {
  width: 100%; padding: 12px 16px; border-radius: var(--radius);
  background: var(--bg-card); border: 1px solid var(--border);
  color: var(--text); font-family: var(--font-cn); font-size: 0.95rem;
  transition: border-color 0.3s;
}
.form-group input:focus, .form-group textarea:focus { outline: none; border-color: var(--cyan); }
.form-group textarea { min-height: 120px; resize: vertical; }

/* ── Responsive ── */
@media (max-width: 768px) {
  .nav { padding: 0 20px; }
  .nav-links { display: none; }
  .section { padding: 60px 20px; }
  .feature-block { grid-template-columns: 1fr; gap: 30px; }
  .feature-block.reverse { direction: ltr; }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 30px; }
  .cards-grid, .case-grid { grid-template-columns: 1fr; }
}