* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
:root {
  --bg: #ffffff;
  --text: #222222;
  --gray: #666;
  --light-gray: #f4f4f4;
  --accent: #111;
  --font: "Inter", system-ui, -apple-system, "Segoe UI", sans-serif;
}
body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
.container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 24px;
}
/* Navigation */
header {
  position: sticky;
  top: 0;
  background: rgba(255,255,255,0.94);
  backdrop-filter: blur(8px);
  z-index: 99;
  border-bottom: 1px solid #eee;
}
.nav-wrap {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 72px;
}
.logo {
  font-size: 20px;
  font-weight: 600;
  text-decoration: none;
  color: var(--text);
  letter-spacing: 1px;
}
.nav-links {
  display: flex;
  gap: 36px;
  align-items: center;
}
.nav-links a {
  text-decoration: none;
  color: var(--gray);
  font-size: 14px;
  font-weight: 500;
  transition: color .2s;
}
.nav-links a:hover { color: #000; }
.lang-switch {
  border: 1px solid #111;
  padding: 7px 16px;
  border-radius: 99px;
  background: #111;
  color: #fff;
  cursor: pointer;
  font-size: 13px;
  font-weight: 500;
  transition: all .2s;
  white-space: nowrap;
}
.lang-switch:hover { background: #333; }

/* Hero / Product grid */
.hero-product { padding: 60px 0; }
.section-title {
  font-size: 32px;
  font-weight: 500;
  margin-bottom: 40px;
}
.product-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(480px, 1fr));
  gap: 48px;
}
.product-card {
  cursor: pointer;
  text-decoration: none;
  color: inherit;
  display: block;
}
.product-card__img {
  width: 100%;
  aspect-ratio: 16/10;
  object-fit: cover;
  background: var(--light-gray);
  margin-bottom: 18px;
  transition: transform .3s ease;
}
.product-card:hover .product-card__img {
  transform: translateY(-6px);
}
.product-card h3 {
  font-size: 22px;
  font-weight: 500;
  margin-bottom: 8px;
}
.product-card p {
  color: var(--gray);
  max-width: 460px;
  font-size: 15px;
}

/* Inner pages */
.page-content {
  padding: 80px 0;
  min-height: calc(100vh - 72px - 120px);
}
.placeholder-block {
  background: var(--light-gray);
  padding: 120px 24px;
  text-align: center;
  color: #999;
  border-radius: 4px;
}

/* Product detail */
.product-detail-wrap {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: start;
}
.product-detail-img {
  width: 100%;
  aspect-ratio: 4/3;
  object-fit: cover;
  background: var(--light-gray);
  border-radius: 4px;
}
.product-detail-text h1 {
  font-size: 36px;
  font-weight: 500;
  margin-bottom: 20px;
}
.spec-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 16px;
  margin-bottom: 24px;
}
.spec-table td {
  border-bottom: 1px solid #eee;
  padding: 10px 8px;
  font-size: 14px;
}
.spec-table tr:first-child td {
  font-weight: 500;
  background: #fafafa;
}
h3 {
  margin: 28px 0 10px;
  font-weight: 500;
  font-size: 18px;
}
ul {
  padding-left: 20px;
  color: var(--gray);
  margin-bottom: 16px;
  font-size: 15px;
}
ul li { margin-bottom: 4px; }

/* Contact form */
form { max-width: 600px; margin-top: 32px; }
.form-item { margin-bottom: 20px; }
.form-item label {
  display: block;
  margin-bottom: 8px;
  font-size: 14px;
}
.form-item input,
.form-item textarea {
  width: 100%;
  border: 1px solid #ddd;
  padding: 12px 14px;
  border-radius: 4px;
  font: inherit;
  font-size: 14px;
}
.form-item input:focus,
.form-item textarea:focus {
  outline: none;
  border-color: #999;
}
button {
  padding: 14px 36px;
  background: #111;
  color: #fff;
  border: 0;
  cursor: pointer;
  font-size: 14px;
  border-radius: 4px;
  transition: background .2s;
}
button:hover { background: #333; }

footer {
  border-top: 1px solid #eee;
  padding: 40px 0;
  font-size: 13px;
  color: #999;
}

/* Language toggle: default English, Chinese hidden */
.cn { display: none; }
.en { display: block; }
body.cn-mode .cn { display: block; }
body.cn-mode .en { display: none; }

@media (max-width: 768px) {
  .nav-links { gap: 16px; }
  .product-grid { grid-template-columns: 1fr; }
  .product-detail-wrap { grid-template-columns: 1fr; gap: 32px; }
  .section-title { font-size: 26px; }
}