/* concept-rf.com 官网样式 —— 与成本系统/物流页视觉统一 */
:root {
  --accent: #007F78;
  --accent-dark: #006460;
  --dark-bar: #252D31;
  --bg: #F7F9FA;
  --card-bg: #FFFFFF;
  --card-border: #DDE3E6;
  --text: #2B3236;
  --text-light: #66757C;
  --radius: 10px;
}

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

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

body {
  font-family: "Microsoft YaHei", "PingFang SC", "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

img { max-width: 100%; display: block; }

.container { max-width: 1080px; margin: 0 auto; padding: 0 16px; }

/* ===== 顶部导航 ===== */
.site-header {
  background: #fff;
  border-bottom: 1px solid var(--card-border);
  color: var(--text);
  position: sticky;
  top: 0;
  z-index: 100;
}
.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 56px;
  flex-wrap: wrap;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  font-size: 18px;
  font-weight: bold;
  text-decoration: none;
}
.brand:hover { text-decoration: none; }
.brand img.logo { height: 30px; width: auto; }
@media (max-width: 720px) { .brand img.logo { height: 24px; } }
.brand .brand-en { font-weight: normal; font-size: 13px; color: #9FB0B8; }

.nav-links { display: flex; gap: 4px; }
.nav-links a {
  color: var(--text-light);
  padding: 8px 14px;
  border-radius: 6px;
  font-size: 15px;
  text-decoration: none;
}
.nav-links a:hover, .nav-links a.active { color: var(--accent); background: rgba(0,127,120,.08); }

/* 移动端导航：汉堡 */
.menu-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text);
  font-size: 24px;
  cursor: pointer;
  padding: 8px;
}
@media (max-width: 720px) {
  .menu-toggle { display: block; }
  .nav-links {
    display: none;
    width: 100%;
    flex-direction: column;
    padding-bottom: 8px;
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 12px 14px; }
}

/* ===== 按钮 ===== */
.btn {
  display: inline-block;
  background: var(--accent);
  color: #fff;
  padding: 10px 22px;
  border-radius: 6px;
  border: none;
  font-size: 15px;
  cursor: pointer;
  text-decoration: none;
  transition: background .15s;
}
.btn:hover { background: var(--accent-dark); text-decoration: none; color: #fff; }
.btn-outline {
  background: transparent;
  color: var(--accent);
  border: 1px solid var(--accent);
}
.btn-outline:hover { background: rgba(0,127,120,.08); color: var(--accent-dark); }

/* ===== 首页 Hero 轮播（参考 Keysight 风格）===== */
.hero {
  position: relative;
  background: var(--dark-bar);
  color: #fff;
  overflow: hidden;
}
.carousel-track { display: flex; transition: transform .5s ease; }

.hero-slide {
  min-width: 100%;
  position: relative;
  min-height: 420px;
  display: flex;
  align-items: center;
}
/* 通栏背景大图（Keysight 风格） */
.hero-slide .bg {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-position: center;
}
/* 背景为空时的兜底底色 */
.hero-slide .bg.empty { background: linear-gradient(120deg, #37454C 0%, #2A383F 100%); }
/* 文字底部压深色渐变，保证可读 */
.hero-slide .overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, rgba(21,27,30,.78) 0%, rgba(21,27,30,.45) 45%, rgba(21,27,30,.15) 100%);
}
/* 轮播文字贴近屏幕左侧（与页面内容栅格无关），整体更靠左 */
.hero-slide .container {
  position: relative;
  z-index: 2;
  width: 100%;
  max-width: none;
  margin: 0;
  padding-top: 72px;
  padding-bottom: 88px;
  padding-left: clamp(16px, 6vw, 110px);
  padding-right: 16px;
}
@media (max-width: 760px) {
  .hero-slide { min-height: 360px; }
  .hero-slide .overlay { background: rgba(21,27,30,.55); }
  .hero-slide .container { padding-top: 44px; padding-bottom: 88px; }
}

.hero-slide .text h1 { font-size: 32px; line-height: 1.3; margin-bottom: 14px; text-shadow: 0 1px 4px rgba(0,0,0,.4); }
.hero-slide .text .sub { color: #E3EAED; font-size: 16px; margin-bottom: 26px; max-width: 560px; text-shadow: 0 1px 3px rgba(0,0,0,.4); }
.hero-slide .text .actions { display: flex; gap: 12px; flex-wrap: wrap; }
@media (max-width: 760px) { .hero-slide .text h1 { font-size: 24px; } }

/* 轮播左右箭头 */
.carousel-btn {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  background: rgba(255,255,255,.12);
  border: none;
  color: #fff;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  font-size: 20px;
  cursor: pointer;
  transition: background .15s;
  z-index: 5;
  display: flex;
  align-items: center;
  justify-content: center;
}
.carousel-btn:hover { background: rgba(255,255,255,.28); }
.carousel-btn.prev { left: 10px; }
.carousel-btn.next { right: 10px; }

/* 轮播圆点 */
.carousel-dots {
  position: absolute;
  bottom: 22px;
  left: 0;
  right: 0;
  display: flex;
  justify-content: center;
  gap: 10px;
}
.carousel-dots button {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  border: none;
  background: rgba(255,255,255,.35);
  cursor: pointer;
  padding: 0;
  transition: background .15s;
}
.carousel-dots button.active { background: #fff; }

/* ===== 卡片 / 区块 ===== */
.section { padding: 44px 0; }
.section-title {
  font-size: 22px;
  margin-bottom: 22px;
  padding-left: 12px;
  border-left: 4px solid var(--accent);
}

.card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  padding: 22px;
}

/* 网格 */
.grid { display: grid; gap: 18px; }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
@media (max-width: 860px) { .grid-3 { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 600px) { .grid-3, .grid-2 { grid-template-columns: 1fr; } }

/* ===== 产品卡片 ===== */
.product-card {
  display: flex;
  flex-direction: column;
  overflow: hidden;
  padding: 0;
  transition: box-shadow .15s, transform .15s;
}
.product-card:hover {
  box-shadow: 0 4px 16px rgba(37,45,49,.10);
  transform: translateY(-2px);
}
.product-card .thumb {
  background: #fff;
  aspect-ratio: 1/1;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}
.product-card .thumb img { width: 100%; height: 100%; object-fit: contain; }
.product-card .thumb .no-img { color: #A9B8BF; font-size: 14px; }
.product-card .body { padding: 16px 18px 18px; flex: 1; display: flex; flex-direction: column; }
.product-card h3 { font-size: 17px; margin-bottom: 4px; }
.product-card .code { color: var(--text-light); font-size: 13px; margin-bottom: 10px; }
.product-card .desc {
  color: var(--text-light);
  font-size: 14px;
  flex: 1;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.product-card .more { margin-top: 12px; font-size: 14px; }

/* ===== 详情页 ===== */
.detail-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1.2fr);
  gap: 24px;
  align-items: start;
}
@media (max-width: 760px) { .detail-layout { grid-template-columns: 1fr; } }
.detail-img {
  background: #fff;
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  aspect-ratio: 1/1;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}
.detail-img img { width: 100%; height: 100%; object-fit: contain; }
.detail-info h1 { font-size: 24px; margin-bottom: 4px; }
.detail-info .code { color: var(--text-light); margin-bottom: 16px; }
.detail-info .desc { margin-bottom: 20px; }

/* 下载列表 */
.download-list { list-style: none; }
.download-list li {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 12px 0;
  border-bottom: 1px solid var(--card-border);
}
.download-list li:last-child { border-bottom: none; }
.file-name { font-size: 15px; word-break: break-all; }
.file-meta { color: var(--text-light); font-size: 12px; }

/* ===== 物流入口横幅 ===== */
.logistics-banner {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-left: 4px solid var(--accent);
  border-radius: var(--radius);
  padding: 20px 22px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

/* ===== 页脚 ===== */
.site-footer {
  background: var(--dark-bar);
  color: #9FB0B8;
  padding: 28px 0;
  font-size: 13px;
  margin-top: 44px;
}
.site-footer a { color: #C9D3D8; }

/* 面包屑 */
.breadcrumb { font-size: 13px; color: var(--text-light); margin-bottom: 18px; }

.empty-tip { color: var(--text-light); text-align: center; padding: 40px 0; }