:root {
  --primary: #0891b2;
  --primary-dark: #0e7490;
  --primary-light: rgba(8,145,178,0.1);
  --primary-glow: rgba(8,145,178,0.2);
  --accent: #6366f1;
  --bg: #eef4fa;
  --bg-secondary: #f6f9fc;
  --bg-card: #ffffff;
  --bg-dark: #0f172a;
  --text: #0f172a;
  --text-secondary: #475569;
  --text-light: #64748b;
  --border: rgba(15,23,42,0.08);
  --border-strong: rgba(8,145,178,0.2);
  --radius: 14px;
  --radius-sm: 10px;
  --shadow: 0 2px 12px rgba(15,23,42,0.06);
  --shadow-md: 0 10px 34px rgba(15,23,42,0.10);
  --max-width: 1100px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; }
.container { max-width: var(--max-width); margin: 0 auto; padding: 0 24px; }

/* Nav */
.site-nav {
  position: sticky; top: 0; z-index: 50;
  background: rgba(238,244,250,0.85);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.brand img { height: 34px; width: auto; display: block; }
.site-nav nav a {
  font-size: 14px; font-weight: 600; color: var(--primary);
  text-decoration: none; padding: 8px 16px; border-radius: 8px;
  border: 1px solid var(--border-strong); transition: all .2s;
}
.site-nav nav a:hover { background: var(--primary-light); }

/* Hero */
.detail-hero { padding: 48px 0 28px; }
.back-link { display: inline-block; font-size: 14px; color: var(--text-light); text-decoration: none; margin-bottom: 22px; transition: color .2s; }
.back-link:hover { color: var(--primary); }
.detail-hero-inner { display: flex; align-items: center; gap: 22px; }
.product-icon {
  width: 72px; height: 72px; border-radius: 18px; flex-shrink: 0;
  display: flex; align-items: center; justify-content: center; font-size: 38px;
  background: var(--primary-light);
}
.tag {
  display: inline-block; background: rgba(8,145,178,0.1); color: var(--primary);
  padding: 3px 12px; border-radius: 999px; font-size: 13px; font-weight: 600;
  border: 1px solid var(--border-strong); margin-bottom: 10px;
}
.detail-hero h1 { font-size: 34px; line-height: 1.25; margin-bottom: 10px; }
.lead { font-size: 16px; color: var(--text-secondary); max-width: 720px; }

/* Sections */
.section { padding: 36px 0; }
.section h2 { font-size: 24px; margin-bottom: 20px; }

/* Media */
.pm-video-ph { width: 100%; aspect-ratio: 16 / 9; border-radius: var(--radius); border: none;
  position: relative; display: flex; align-items: center; justify-content: center;
  flex-direction: column; gap: 12px;
  background: linear-gradient(135deg, #0f172a, #1e293b); color: #cbd5e1;
}
.pm-video { width: 100%; height: auto; max-height: 560px; object-fit: contain; border-radius: var(--radius); border: none; display: block; background: #000; }
.pm-video-ph .play {
  width: 62px; height: 62px; border-radius: 50%;
  background: rgba(34,211,238,0.15); border: 2px solid rgba(34,211,238,0.5);
  display: flex; align-items: center; justify-content: center;
  color: #22d3ee; font-size: 24px;
}
.pm-video-ph p { font-size: 14px; margin: 0; color: #94a3b8; }
.pm-gallery { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin-top: 12px; }
.pm-shot, .pm-shot-ph {
  width: 100%; aspect-ratio: 9 / 16; border-radius: var(--radius-sm);
  object-fit: cover; background: #f1f5f9; border: 1px solid var(--border);
}
.pm-shot-ph {
  display: flex; align-items: center; justify-content: center;
  background: linear-gradient(135deg, #e2e8f0, #f1f5f9); color: var(--text-light);
  font-size: 13px; text-align: center; line-height: 1.5;
}
.media-note {
  margin-top: 16px; font-size: 13px; color: var(--text-light);
  background: var(--primary-light); border: 1px dashed var(--border-strong);
  border-radius: var(--radius-sm); padding: 12px 16px;
}

/* Features */
.feature-list { list-style: none; display: grid; grid-template-columns: 1fr 1fr; gap: 14px 28px; }
.feature-list li {
  position: relative; padding-left: 26px; font-size: 15px; color: var(--text-secondary);
}
.feature-list li::before {
  content: "✓"; position: absolute; left: 0; top: 0;
  width: 18px; height: 18px; border-radius: 50%;
  background: var(--primary); color: #fff; font-size: 11px; font-weight: 700;
  display: flex; align-items: center; justify-content: center;
}

/* CTA */
.detail-cta {
  background: linear-gradient(135deg, rgba(8,145,178,0.08), rgba(99,102,241,0.06));
  border-top: 1px solid var(--border); border-bottom: 1px solid var(--border);
}
.detail-cta h2 { margin-bottom: 8px; }
.detail-cta p { color: var(--text-secondary); margin-bottom: 20px; }
.cta-actions { display: flex; gap: 14px; flex-wrap: wrap; }

/* Buttons */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 12px 26px; border-radius: 10px; font-size: 15px; font-weight: 600;
  text-decoration: none; cursor: pointer; transition: all .2s; border: 1.5px solid transparent;
}
.btn-primary { background: var(--primary); color: #fff; box-shadow: 0 4px 14px var(--primary-glow); }
.btn-primary:hover { background: var(--primary-dark); transform: translateY(-1px); }
.btn-outline { background: transparent; color: var(--primary); border-color: var(--primary); }
.btn-outline:hover { background: var(--primary-light); }

/* Footer */
.site-footer { background: var(--bg-secondary); border-top: 1px solid var(--border); padding: 32px 0; margin-top: 20px; }
.footer-inner { text-align: center; }
.footer-inner p { font-size: 13px; color: var(--text-light); margin-bottom: 6px; }

@media (max-width: 720px) {
  .detail-hero-inner { flex-direction: column; align-items: flex-start; }
  .feature-list { grid-template-columns: 1fr; }
  .pm-gallery { grid-template-columns: repeat(3, 1fr); }
  .detail-hero h1 { font-size: 28px; }
}