/* ============================================
   layout.css — 包印网商城 公共头部 / 底部
   头部：① 墨蓝深色顶条  ② 白底品牌行（logo + 方角搜索[左嵌分类下拉 + 橙按钮] + 描边购物车块）
        ③ 墨蓝实底 sticky 导航条（当前项橙色胶囊 + 左侧「全部商品分类」常驻竖排侧栏）
   底部：① 橙蓝斜切招商 CTA 区  ② 白底四宫格保障条（图标在上）
        ③ 暖纸白浅色主页脚（品牌 + 三列链接 + 联系备案卡 + 两平台独立说明）  ④ 墨蓝深色版权条
   配色：品牌墨蓝 #04539F + 亮蓝 #198DFB + 阳光橙 #F5871F + 暖纸白底 #F6F4F0 + 墨蓝深块 #0A2B52
   类名前缀：by_ （交互 ID 沿用 xy_hd_bar / zh_mb_* / xy_msearch / zh_feedback_btn 不变）
   ============================================ */

.by_hd { position: relative; z-index: 1000; background: #fff; }

/* ============================================
   ① 顶部细条 —— 墨蓝深色（与上一版浅蓝顶条明暗反相）
   ============================================ */
.by_top { background: var(--by-navy-deep); color: rgba(255,255,255,.72); font-size: 12.5px; }
.by_top_in { max-width: 1300px; margin: 0 auto; padding: 0 20px; height: 38px; display: flex; align-items: center; justify-content: space-between; gap: 20px; }
.by_top_l { display: flex; align-items: center; gap: 18px; min-width: 0; overflow: hidden; flex: 1; }
.by_top_ann { display: inline-flex; align-items: center; gap: 8px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.by_top_ann i { color: var(--by-orange-light); }
.by_top_tag { display: inline-flex; align-items: center; gap: 6px; flex-shrink: 0; font-size: 11.5px; color: var(--by-sky-soft); border: 1px solid rgba(169,212,254,.32); border-radius: var(--by-radius-sm); padding: 2px 9px; }

.by_top_r { display: flex; align-items: center; flex-shrink: 0; }
.by_top_r a, .by_top_tel { padding: 0 12px; color: rgba(255,255,255,.72); position: relative; white-space: nowrap; line-height: 1; }
.by_top_tel { display: inline-flex; align-items: center; gap: 6px; }
.by_top_tel strong { color: #fff; font-weight: 700; letter-spacing: .3px; }
.by_top_r a { transition: color .18s; }
.by_top_r a + a::before, .by_top_tel + a::before { content: ''; position: absolute; left: 0; top: 50%; transform: translateY(-50%); width: 1px; height: 11px; background: rgba(255,255,255,.16); }
.by_top_r a:hover { color: #fff; }
.by_top_r a i { margin-right: 5px; opacity: .8; }
.by_top_r a.by_top_join { color: #fff; background: var(--by-grad-orange); border-radius: var(--by-radius-sm); padding: 5px 14px; margin-left: 14px; font-weight: 700; }
.by_top_r a.by_top_join::before { display: none; }
.by_top_r a.by_top_join:hover { filter: brightness(1.08); }
.by_top_r a.by_top_join i { opacity: 1; }

/* ============================================
   ② 品牌行 —— 白底：logo + 方角搜索 + 描边购物车块
   ============================================ */
.by_main { background: #fff; position: relative; border-bottom: 1px solid var(--by-line); }
.by_main_in { max-width: 1300px; margin: 0 auto; padding: 0 20px; height: 96px; display: flex; align-items: center; gap: 28px; }

.by_burger { display: none; width: 42px; height: 42px; border: 1px solid var(--by-line); background: #fff; color: var(--by-blue); border-radius: var(--by-radius); font-size: 18px; align-items: center; justify-content: center; flex: 0 0 auto; }

/* logo + 竖线副标题 */
.by_logo { flex: 0 0 auto; display: flex; align-items: center; gap: 16px; }
.by_logo img { height: 46px; width: auto; display: block; }
.by_logo_sub { display: flex; flex-direction: column; gap: 3px; padding-left: 16px; border-left: 1px solid var(--by-line); }
.by_logo_sub strong { font-size: 15px; font-weight: 700; color: var(--by-blue-deep); letter-spacing: .5px; line-height: 1; }
.by_logo_sub small { font-size: 11.5px; color: var(--by-ink-3); letter-spacing: .5px; line-height: 1; }

/* 搜索：方角矩形 + 左嵌分类下拉 + 橙色实心按钮 */
.by_search { flex: 1 1 auto; max-width: 590px; position: relative; display: flex; align-items: stretch; height: 46px; border: 2px solid var(--by-blue); border-radius: var(--by-radius); background: #fff; }
.by_search_cat { position: relative; flex: 0 0 auto; display: flex; align-items: center; }
.by_search_cat select { -webkit-appearance: none; appearance: none; border: none; outline: none; background: var(--by-blue-tint); color: var(--by-blue-deep); font-size: 13px; font-weight: 600; font-family: inherit; height: 100%; padding: 0 26px 0 14px; cursor: pointer; border-right: 1px solid var(--by-blue-tint2); }
.by_search_cat::after { content: '\f107'; font-family: 'Font Awesome 5 Free'; font-weight: 900; position: absolute; right: 10px; top: 50%; transform: translateY(-50%); font-size: 12px; color: var(--by-blue); pointer-events: none; }
.by_search input { flex: 1; border: none; outline: none; background: transparent; padding: 0 10px 0 16px; font-size: 14px; color: var(--by-ink); font-family: inherit; min-width: 0; }
.by_search input::placeholder { color: var(--by-ink-3); }
.by_search button { flex-shrink: 0; display: inline-flex; align-items: center; gap: 8px; padding: 0 30px; border: none; cursor: pointer; background: var(--by-grad-orange); color: #fff; font-size: 14.5px; font-weight: 700; letter-spacing: 2px; transition: filter .2s; }
.by_search button:hover { filter: brightness(1.07); }
.by_search_hot { position: absolute; top: calc(100% + 9px); left: 2px; display: flex; align-items: center; gap: 6px 12px; flex-wrap: wrap; font-size: 12px; color: var(--by-ink-3); white-space: nowrap; }
.by_search_hot a { color: var(--by-ink-2); transition: color .18s; }
.by_search_hot a:hover { color: var(--by-orange-deep); }

/* 右侧：客服热线 + 账户 + 购物车（描边按钮块） */
.by_main_r { flex: 0 0 auto; margin-left: auto; display: flex; align-items: center; gap: 14px; }
.by_msearch { display: none; width: 42px; height: 42px; border: 1px solid var(--by-line); background: #fff; color: var(--by-blue); border-radius: var(--by-radius); font-size: 17px; align-items: center; justify-content: center; }

.by_hot { display: flex; align-items: center; gap: 10px; padding-right: 14px; border-right: 1px solid var(--by-line); }
.by_hot_ic { width: 36px; height: 36px; flex-shrink: 0; border-radius: var(--by-radius); background: var(--by-blue-tint); color: var(--by-blue); display: inline-flex; align-items: center; justify-content: center; font-size: 16px; }
.by_hot_tx { display: flex; flex-direction: column; gap: 2px; line-height: 1; }
.by_hot_tx small { font-size: 11.5px; color: var(--by-ink-3); }
.by_hot_tx strong { font-size: 16px; font-weight: 800; color: var(--by-blue-deep); letter-spacing: .3px; }

.by_act { display: inline-flex; align-items: center; gap: 7px; height: 40px; padding: 0 16px; border: 1px solid var(--by-line); border-radius: var(--by-radius); font-size: 13.5px; font-weight: 600; color: var(--by-ink-2); transition: all .18s; }
.by_act:hover { border-color: var(--by-blue); color: var(--by-blue); }
.by_act i { font-size: 14px; }

.by_cart { position: relative; display: inline-flex; align-items: center; gap: 8px; height: 40px; padding: 0 20px; border: 1px solid var(--by-orange); border-radius: var(--by-radius); background: var(--by-orange-tint); color: var(--by-orange-deep); font-size: 13.5px; font-weight: 700; transition: all .18s; }
.by_cart:hover { background: var(--by-orange); color: #fff; }
.by_cart_badge { position: absolute; top: -8px; right: -8px; min-width: 19px; height: 19px; padding: 0 5px; border-radius: 999px; background: #E4572E; color: #fff; font-size: 11px; font-weight: 700; font-style: normal; display: inline-flex; align-items: center; justify-content: center; box-shadow: 0 2px 6px rgba(228,87,46,.4); }

/* ============================================
   ③ 导航行 —— 墨蓝实底 sticky + 橙色胶囊高亮 + 左侧全部分类
   ============================================ */
.by_nav { position: sticky; top: 0; z-index: 1000; background: var(--by-grad-navy-bar); }
.by_nav.is_stuck { box-shadow: 0 6px 20px rgba(6,32,64,.28); }
.by_nav_in { max-width: 1300px; margin: 0 auto; padding: 0 20px; height: 48px; display: flex; align-items: stretch; gap: 0; position: relative; }

/* 左侧「全部商品分类」 */
.by_allcat { position: relative; flex: 0 0 240px; }
.by_allcat_btn { width: 100%; height: 100%; display: flex; align-items: center; gap: 10px; padding: 0 18px; border: none; background: var(--by-orange); color: #fff; font-size: 15px; font-weight: 700; letter-spacing: 1px; font-family: inherit; cursor: pointer; }
.by_allcat_btn .by_allcat_ar { margin-left: auto; font-size: 13px; transition: transform .2s; }
.by_allcat:hover .by_allcat_ar { transform: rotate(-90deg); }

/* 竖排分类面板（默认悬停展开；首页由 home.css 设为常驻展开） */
.by_catpanel { display: none; position: absolute; top: 100%; left: 0; width: 240px; background: #fff; border: 1px solid var(--by-line); border-top: none; box-shadow: var(--by-shadow-lg); padding: 6px 0; }
.by_allcat:hover .by_catpanel { display: block; }
.by_cat_row { position: relative; }
.by_cat_link { display: flex; align-items: center; gap: 10px; padding: 0 18px; height: 44px; font-size: 14px; color: var(--by-ink); transition: background .16s, color .16s; }
.by_cat_link > i:first-child { width: 18px; text-align: center; font-size: 14px; color: var(--by-blue); flex-shrink: 0; }
.by_cat_link .by_cat_ar { margin-left: auto; font-size: 12px; color: var(--by-ink-3); }
.by_cat_row:hover .by_cat_link { background: var(--by-blue-tint); color: var(--by-blue-deep); }
.by_cat_row:hover .by_cat_link > i:first-child { color: var(--by-orange-deep); }

/* 二级：右侧飞出面板 */
.by_cat_fly { display: none; position: absolute; top: -7px; left: 100%; min-width: 420px; max-width: 520px; background: #fff; border: 1px solid var(--by-line); box-shadow: var(--by-shadow-lg); padding: 18px 22px; }
.by_cat_row:hover .by_cat_fly { display: block; }
.by_cat_fly_hd { display: flex; align-items: center; gap: 8px; font-size: 14px; font-weight: 700; color: var(--by-blue-deep); padding-bottom: 10px; margin-bottom: 12px; border-bottom: 1px dashed var(--by-line); }
.by_cat_fly_hd i { color: var(--by-orange); }
.by_cat_fly_subs { display: flex; flex-wrap: wrap; gap: 8px 10px; }
.by_cat_fly_subs a { font-size: 13px; color: var(--by-ink-2); padding: 5px 12px; background: var(--by-paper); border-radius: var(--by-radius-sm); transition: all .16s; }
.by_cat_fly_subs a:hover { background: var(--by-blue); color: #fff; }
.by_cat_fly_desc { margin-top: 12px; font-size: 12.5px; line-height: 1.8; color: var(--by-ink-3); }

/* 主导航 */
.by_nav_menu { flex: 1 1 auto; min-width: 0; display: flex; align-items: center; gap: 4px; padding-left: 16px; overflow: hidden; }
.by_nav_menu a { position: relative; display: inline-flex; align-items: center; height: 32px; padding: 0 16px; border-radius: var(--by-radius-lg); font-size: 14.5px; font-weight: 600; color: rgba(255,255,255,.82); white-space: nowrap; transition: all .18s; }
.by_nav_menu a:hover { color: #fff; background: rgba(255,255,255,.1); }
.by_nav_menu a.active { color: #fff; background: var(--by-orange); box-shadow: 0 3px 12px rgba(245,135,31,.4); }

.by_nav_cta { flex: 0 0 auto; display: inline-flex; align-items: center; gap: 7px; align-self: center; padding: 0 16px; height: 32px; border: 1px solid rgba(255,255,255,.34); border-radius: var(--by-radius); color: #fff; font-size: 13.5px; font-weight: 600; white-space: nowrap; transition: all .18s; }
.by_nav_cta:hover { background: #fff; color: var(--by-blue-deep); border-color: #fff; }

/* ============================================
   ④ 底部 —— 橙蓝斜切招商 CTA 区
   ============================================ */
.by_ft_cta { position: relative; overflow: hidden; background: var(--by-grad-navy); }
.by_ft_cta::before { content: ''; position: absolute; top: 0; right: 0; bottom: 0; width: 46%; background: var(--by-grad-orange); transform: skewX(-14deg); transform-origin: top; right: -6%; }
.by_ft_cta::after { content: ''; position: absolute; inset: 0; background: radial-gradient(circle at 20% 120%, rgba(25,141,251,.35) 0%, transparent 46%); }
.by_ft_cta_in { position: relative; z-index: 1; max-width: 1300px; margin: 0 auto; padding: 38px 20px; display: flex; align-items: center; justify-content: space-between; gap: 28px; flex-wrap: wrap; }
.by_ft_cta_tx { display: flex; align-items: center; gap: 18px; min-width: 0; }
.by_ft_cta_tx > i { width: 54px; height: 54px; flex-shrink: 0; border-radius: var(--by-radius); background: rgba(255,255,255,.14); border: 1px solid rgba(255,255,255,.24); color: #fff; display: inline-flex; align-items: center; justify-content: center; font-size: 22px; }
.by_ft_cta_txt strong { display: block; font-size: 22px; font-weight: 800; color: #fff; letter-spacing: .5px; }
.by_ft_cta_txt span { display: block; margin-top: 7px; font-size: 13.5px; color: rgba(255,255,255,.78); letter-spacing: .5px; }
.by_ft_cta_btns { display: flex; align-items: center; gap: 12px; flex-shrink: 0; }
.by_ft_cta_main { display: inline-flex; align-items: center; gap: 8px; height: 46px; padding: 0 28px; border-radius: var(--by-radius); background: #fff; color: var(--by-blue-deep); font-size: 15px; font-weight: 700; box-shadow: 0 8px 22px rgba(6,32,64,.24); transition: transform .18s; }
.by_ft_cta_main:hover { transform: translateY(-2px); color: var(--by-blue-deep); }
.by_ft_cta_ghost { display: inline-flex; align-items: center; gap: 8px; height: 46px; padding: 0 24px; border-radius: var(--by-radius); border: 1px solid rgba(255,255,255,.5); color: #fff; font-size: 14.5px; font-weight: 600; transition: all .18s; }
.by_ft_cta_ghost:hover { background: rgba(255,255,255,.14); color: #fff; }

/* ============================================
   ⑤ 服务保障条 —— 白底四宫格（图标在上、文字在下 + 竖分隔线）
   ============================================ */
.by_ft_assure { background: #fff; border-bottom: 1px solid var(--by-line); }
.by_ft_assure_in { max-width: 1300px; margin: 0 auto; padding: 34px 20px; display: grid; grid-template-columns: repeat(4, 1fr); }
.by_ft_assure_item { position: relative; display: flex; flex-direction: column; align-items: center; text-align: center; gap: 12px; padding: 0 16px; }
.by_ft_assure_item + .by_ft_assure_item::before { content: ''; position: absolute; left: 0; top: 8px; bottom: 8px; width: 1px; background: var(--by-line); }
.by_ft_assure_ic { width: 50px; height: 50px; border-radius: var(--by-radius); background: var(--by-blue-tint); color: var(--by-blue); display: inline-flex; align-items: center; justify-content: center; font-size: 21px; transition: all .2s; }
.by_ft_assure_item:hover .by_ft_assure_ic { background: var(--by-orange); color: #fff; }
.by_ft_assure_tx strong { display: block; font-size: 15px; font-weight: 700; color: var(--by-ink); }
.by_ft_assure_tx small { display: block; margin-top: 5px; font-size: 12.5px; color: var(--by-ink-3); }

/* ============================================
   ⑥ 主页脚 —— 暖纸白浅色底（与上一版深藏蓝大页脚深浅反相）
   ============================================ */
.by_ft_main { background: var(--by-paper); border-top: 3px solid var(--by-blue); }
.by_ft_main_in { max-width: 1300px; margin: 0 auto; padding: 46px 20px 34px; display: grid; grid-template-columns: 1.5fr 1fr 1fr 1.4fr; gap: 40px; }

.by_ft_brand { min-width: 0; }
.by_ft_logo img { height: 42px; width: auto; display: block; }
.by_ft_desc { margin-top: 16px; font-size: 13px; line-height: 2; color: var(--by-ink-2); }
.by_ft_hot { display: inline-flex; align-items: center; gap: 11px; margin-top: 18px; padding: 10px 16px; background: #fff; border: 1px solid var(--by-line); border-radius: var(--by-radius); }
.by_ft_hot_ic { width: 34px; height: 34px; flex-shrink: 0; border-radius: var(--by-radius-sm); background: var(--by-orange-tint); color: var(--by-orange-deep); display: inline-flex; align-items: center; justify-content: center; font-size: 15px; }
.by_ft_hot_tx { display: flex; flex-direction: column; gap: 3px; line-height: 1; }
.by_ft_hot_tx small { font-size: 11.5px; color: var(--by-ink-3); }
.by_ft_hot_tx strong { font-size: 17px; font-weight: 800; color: var(--by-blue-deep); letter-spacing: .3px; }

.by_ft_col h4 { font-size: 15px; font-weight: 700; color: var(--by-ink); padding-bottom: 12px; margin-bottom: 14px; border-bottom: 1px solid var(--by-line); position: relative; }
.by_ft_col h4::after { content: ''; position: absolute; left: 0; bottom: -1px; width: 34px; height: 2px; background: var(--by-orange); }
.by_ft_col ul { list-style: none; }
.by_ft_col li { margin-bottom: 11px; }
.by_ft_col a, .by_ft_li { display: inline-flex; align-items: flex-start; gap: 7px; font-size: 13px; color: var(--by-ink-2); line-height: 1.7; transition: color .18s; }
.by_ft_col a i, .by_ft_li i { font-size: 11px; color: var(--by-ink-3); margin-top: 5px; flex-shrink: 0; }
.by_ft_col a:hover { color: var(--by-blue); }
.by_ft_col a:hover i { color: var(--by-orange); }

/* 右侧联系与备案卡 */
.by_ft_card { background: #fff; border: 1px solid var(--by-line); border-radius: var(--by-radius); padding: 20px; }
.by_ft_card h4 { font-size: 15px; font-weight: 700; color: var(--by-ink); margin-bottom: 14px; display: flex; align-items: center; gap: 8px; }
.by_ft_card h4 i { color: var(--by-blue); }
.by_ft_card_row { display: flex; align-items: flex-start; gap: 10px; font-size: 12.5px; line-height: 1.85; color: var(--by-ink-2); padding: 9px 0; border-bottom: 1px dashed var(--by-line); }
.by_ft_card_row:last-child { border-bottom: none; }
.by_ft_card_row > i { width: 15px; text-align: center; color: var(--by-blue); margin-top: 4px; flex-shrink: 0; }
.by_ft_card_row b { font-weight: 700; color: var(--by-ink); }
.by_ft_card_row a { color: var(--by-ink-2); }
.by_ft_card_row a:hover { color: var(--by-blue); }

/* ============================================
   ⑦ 版权条 —— 墨蓝深色收口
   ============================================ */
.by_ft_copy { background: var(--by-navy-deep); color: rgba(255,255,255,.6); font-size: 12.5px; }
.by_ft_copy_in { max-width: 1300px; margin: 0 auto; padding: 16px 20px; display: flex; align-items: center; justify-content: center; flex-wrap: wrap; gap: 8px 22px; text-align: center; }
.by_ft_copy a { color: rgba(255,255,255,.6); transition: color .18s; }
.by_ft_copy a:hover { color: #fff; }
.by_ft_copy_pwd { color: rgba(255,255,255,.35); }

/* ============================================
   响应式
   ============================================ */
@media (max-width: 1200px) {
    .by_logo_sub { display: none; }
    .by_allcat { flex: 0 0 180px; }
    .by_catpanel { width: 180px; }
    .by_ft_main_in { grid-template-columns: 1.4fr 1fr 1.2fr; }
    .by_ft_main_in .by_ft_col:nth-of-type(3) { display: none; }
}

@media (max-width: 992px) {
    .by_top_l { display: none; }
    .by_top_in { justify-content: flex-end; }
    .by_hot { display: none; }
    .by_main_in { height: 78px; gap: 18px; }
    .by_search { max-width: none; }
    .by_search_cat { display: none; }
    .by_search_hot { display: none; }
    .by_act span { display: none; }
    .by_act { padding: 0 13px; }
    .by_cart span { display: none; }
    .by_cart { padding: 0 15px; }
    .by_ft_main_in { grid-template-columns: 1fr 1fr; gap: 28px; }
    .by_ft_main_in .by_ft_col:nth-of-type(3) { display: block; }
    .by_ft_cta_in { padding: 30px 20px; }
    .by_ft_cta_txt strong { font-size: 19px; }
}

@media (max-width: 768px) {
    /* 顶条只保留「客服电话 + 商家入驻」，其余链接抽屉里已有，避免右侧溢出 */
    .by_top { overflow: hidden; }
    .by_top_in { padding: 0 14px; }
    .by_top_r a:not(.by_top_join) { display: none; }
    .by_top_tel { padding-left: 0; }
    .by_top_r a.by_top_join { margin-left: 10px; }

    .by_burger { display: inline-flex; }
    .by_msearch { display: inline-flex; }
    .by_main_in { height: 62px; gap: 12px; padding: 0 14px; }
    .by_logo img { height: 34px; }
    .by_search { display: none; }
    .by_main_r { gap: 8px; }
    .by_act { display: none; }
    .by_nav { display: none; }
    .by_ft_assure_in { grid-template-columns: repeat(2, 1fr); gap: 26px 0; padding: 26px 14px; }
    .by_ft_assure_item:nth-child(odd)::before { display: none; }
    .by_ft_assure_item:nth-child(3)::before { display: block; }
    .by_ft_main_in { grid-template-columns: 1fr; gap: 24px; padding: 32px 16px 24px; }
    .by_ft_cta_in { flex-direction: column; align-items: flex-start; gap: 20px; }
    .by_ft_cta::before { width: 100%; right: -40%; }
    .by_ft_cta_btns { width: 100%; }
    .by_ft_cta_main, .by_ft_cta_ghost { flex: 1; justify-content: center; padding: 0 14px; }
    .by_ft_copy_in { padding: 14px 16px; gap: 6px 14px; font-size: 12px; }
}