:root {
    /* 颜色系统 - 设计令牌 */
    --primary: #0d6efd;
    --primary-hover: #0b5ed7;
    --primary-light: #3d8bfd;
    --dark: #1a1d21;
    --dark-secondary: #2d3748;
    --bg: #ffffff;
    --bg-alt: #f8f9fa;
    --text: #333333;
    --text-secondary: #6c757d;
    --border: #e9ecef;
    /* 渐变 */
    --gradient-hero: linear-gradient(135deg, var(--dark) 0%, var(--dark-secondary) 100%);
    /* 阴影 */
    --shadow-card: 0 0.5rem 1rem rgba(0,0,0,0.1);
    --shadow-card-hover: 0 0.5rem 1rem rgba(0,0,0,0.15);
    /* 圆角 */
    --radius-card: 12px;
    --radius-btn: 8px;
}
body { font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Microsoft YaHei", sans-serif; color: var(--text); }
.navbar-brand { font-weight: 700; font-size: 1.3rem; }
.navbar-brand i { color: var(--primary); }
.hero { background: var(--gradient-hero); color: var(--bg); padding: 4rem 0; }
.hero h1 { font-weight: 800; }
.section-title { font-weight: 700; margin-bottom: 1.5rem; padding-bottom: 0.5rem; border-bottom: 2px solid var(--primary); display: inline-block; }
.card { transition: transform 0.2s, box-shadow 0.2s; border: none; }
.card:hover { transform: translateY(-3px); box-shadow: var(--shadow-card-hover); }
.card-img-top { height: 200px; object-fit: cover; }
footer { background: var(--dark); color: rgba(255,255,255,0.6); padding: 2rem 0; }
footer a { color: rgba(255,255,255,0.6); text-decoration: none; }
footer a:hover { color: var(--bg); }
.breadcrumb { background: transparent; padding: 0; }
/* V2.9.2 分类导航选中态：用左边框+浅蓝底替代Bootstrap默认蓝色填充，与card-header区分 */
#cateTree .list-group-item.active {
    background: #eef2ff !important;
    color: #4f46e5 !important;
    font-weight: 600;
    border-left: 3px solid #4f46e5 !important;
    box-shadow: inset 0 0 0 1px rgba(79,70,229,.12);
    z-index: 1;
}
#cateTree .list-group-item {
    border-left: 3px solid transparent;
    transition: all .15s ease;
}

/* V2.9.44 Banner 轮播图：统一高度 + 背景填充（修复首张 banner 显示异常） */
.banner-slide {
    height: 450px;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}
.banner-img {
    max-height: 450px;
    width: auto;
    display: block;
    margin: 0 auto;
}
.carousel-caption {
    background: rgba(0, 0, 0, 0.4);
    border-radius: 8px;
    padding: 1rem;
}

/* 轮播图左右箭头：半透明圆形背景确保白色箭头在任何背景上都可见 */
#homeBanner .carousel-control-prev,
#homeBanner .carousel-control-next {
    width: 44px;
    height: 44px;
    top: 50%;
    transform: translateY(-50%);
    background: rgba(0, 0, 0, 0.35);
    border-radius: 50%;
    opacity: 0.6;
    transition: opacity 0.2s, background 0.2s;
}
#homeBanner .carousel-control-prev {
    left: 16px;
}
#homeBanner .carousel-control-next {
    right: 16px;
}
#homeBanner .carousel-control-prev:hover,
#homeBanner .carousel-control-next:hover {
    background: rgba(0, 0, 0, 0.55);
    opacity: 1;
}