/* 汉堡按钮默认隐藏（≤820 块中启用） */
.nav-btn { display: none; }

/* ===== MBKFW 响应式（桌面优先，向下断点适配手机） ===== */

/* 基础流体容器 */
.wrap { width: min(1400px, 100% - 30px); margin: 0 auto; }

/* ---------- ≤1280px：小桌面/横屏平板 ---------- */
@media (max-width: 1280px) {
  .grid-4 { grid-template-columns: repeat(3, 1fr); }
  .grid-5 { grid-template-columns: repeat(4, 1fr); }
  .ai-grid { grid-template-columns: repeat(4, 1fr); }
  .homeslide .sart { width: 420px; height: 300px; }
  .layout .side { width: 270px; }
}

/* ---------- ≤1024px：竖屏平板 ---------- */
@media (max-width: 1024px) {
  /* 头部两行化 */
  .header .wrap { flex-wrap: wrap; gap: 12px 16px; }
  .logo { margin-right: 0; }
  .searchbox { order: 3; max-width: none; width: 100%; flex-basis: 100%; }
  .hotwords { display: none; }
  .header-actions { margin-left: auto; }
  .topbar .left em { display: none; }

  /* 布局纵向 */
  .layout, .member-layout, .mnews { flex-direction: column; }
  .layout .side, .member-side { width: 100%; }
  .layout .side { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
  .layout .side .panel { margin-bottom: 0; }

  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .grid-5 { grid-template-columns: repeat(3, 1fr); }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .ai-grid { grid-template-columns: repeat(3, 1fr); }

  .detail-top { flex-direction: column; }
  .dpic { width: 100%; }
  .dpic .mainpic { width: 100%; height: auto; }

  .homeslide { height: 440px; }
  .homeslide .sart { width: 360px; height: 260px; }
  .homeslide .slide .inner, .homeslide .inner { width: auto; padding: 0 16px; }
  .homeslide .stext h2 { font-size: 32px; }

  .vgrid { grid-template-columns: repeat(2, 1fr); }
  .cgrid { grid-template-columns: 1fr; }
  .sol-grid { grid-template-columns: repeat(2, 1fr); }
  .power-grid { grid-template-columns: repeat(2, 1fr); }
  .tst-grid { grid-template-columns: repeat(2, 1fr); }
  .news-grid { grid-template-columns: repeat(2, 1fr); }
  .logo-wall .lw-track span { min-width: 100px; }

  .asset-cards { grid-template-columns: repeat(2, 1fr); }
  .fg-list { flex-wrap: wrap; gap: 14px 26px; }
}

/* ---------- ≤820px：大屏手机/小平板 ---------- */
@media (max-width: 820px) {
  /* 顶部工具条精简 */
  .topbar .left { display: none; }
  .topbar .wrap { justify-content: center; }

  /* 导航折叠为汉堡 */
  .nav { min-height: 50px; }
  .nav .wrap { position: relative; display: block; }
  .nav-btn { display: flex; }
  .nav .wrap > ul {
    display: none;
    position: absolute; left: 0; right: 0; top: 100%;
    background: var(--c-panel);
    box-shadow: 0 18px 34px rgba(0, 0, 0, .18);
    flex-direction: column;
    padding: 8px 0;
    max-height: 70vh; overflow: auto;
  }
  .nav.open .wrap > ul { display: flex; animation: navDrop .25s ease; }
  .nav .wrap > ul > li > a { color: var(--c-text); line-height: 46px; font-size: 15px; border-bottom: 1px solid var(--c-border); border-radius: 0; }
  .nav .wrap > ul > li > a.active { color: var(--c-primary); }
  .nav .wrap > ul > li:hover > a { background: var(--c-tag-bg); color: var(--c-primary); }
  .nav .mega { position: static; display: none; box-shadow: none; min-width: 0; padding: 6px 18px 12px; border-radius: 0; background: var(--c-tag-bg); }
  .nav .wrap > ul > li:hover .mega { display: block; }
  .mega-grid { grid-template-columns: 1fr; }

  .layout .side { grid-template-columns: 1fr; }
  .mgrid { grid-template-columns: repeat(2, 1fr); }
  .grid-5 { grid-template-columns: repeat(2, 1fr); }
  .ai-grid { grid-template-columns: repeat(2, 1fr); }
  .sol-grid, .tst-grid, .news-grid, .power-grid, .vgrid { grid-template-columns: repeat(2, 1fr); }

  .homeslide { height: 380px; }
  .homeslide .sart { display: none; }
  .homeslide .stext h2 { font-size: 26px; }
  .homeslide .stext p { font-size: 14px; }

  .dinfo h1 { font-size: 19px; }
  .dinfo .pricebox .p { font-size: 22px; }
  .buyrow { flex-wrap: wrap; }
  .buyrow .btn { flex: 1 1 46%; text-align: center; }

  .muban-hero { flex-direction: column; align-items: flex-start; gap: 14px; padding: 24px 22px; }
  .muban-hero h1 { font-size: 20px; }

  /* 表格横向滚动（面板承载） */
  .panel, .tabcon { overflow-x: auto; }
  .stable, .cart-table, .paramtable { min-width: 620px; }
  .tabs { overflow-x: auto; }
  .tabs a { white-space: nowrap; padding: 12px 16px; }

  .footer .cols { flex-wrap: wrap; gap: 22px 30px; }
  .footer .qrs { margin-left: 0; }
  .footer-guarantee .fg-list { display: none; }

  .floatbar { display: none; }
  .pages { flex-wrap: wrap; }
}

/* ---------- ≤560px：手机 ---------- */
@media (max-width: 560px) {
  body { font-size: 13px; }
  .header { padding: 12px 0; }
  .header .wrap { gap: 10px; }
  .logo svg { height: 42px; }
  .header .slogan { display: none; }
  .header-actions { gap: 8px; }
  .btn-signin { padding: 7px 12px; font-size: 13px; }
  .btn-cart { padding: 8px 14px; font-size: 13px; }
  .searchbox select { display: none; }
  .searchbox button { width: 76px; letter-spacing: 2px; }

  .grid-4, .grid-3, .grid-5, .ai-grid, .sol-grid, .tst-grid, .news-grid, .power-grid, .vgrid, .mfeat-grid { grid-template-columns: 1fr; }
  .pcard .thumb { height: 170px; }

  .homeslide { height: 320px; }
  .homeslide .stext h2 { font-size: 21px; margin-bottom: 10px; }
  .homeslide .stext p { font-size: 13px; line-height: 1.8; }
  .homeslide .stext .k { font-size: 12px; margin-bottom: 10px; }
  .homeslide .arr { display: none; }

  .filterbar { padding: 2px 12px; }
  .frow { flex-direction: column; padding: 8px 0; }
  .frow .fl { line-height: 22px; margin-bottom: 4px; }
  .frow .fopts a { padding: 3px 10px; margin: 0 4px 6px 0; }
  .sortbar { flex-wrap: wrap; }

  .mcard { padding: 18px 14px; }
  .mp-now b { font-size: 26px; }
  .mdur button { flex: 1; padding: 9px 0; }
  .mhero-btns { flex-wrap: wrap; }
  .mhero-btns .btn { flex: 1 1 46%; text-align: center; }

  .asset-cards { grid-template-columns: repeat(2, 1fr); gap: 10px; }
  .asset { padding: 14px 8px; }
  .asset .num { font-size: 20px; }

  .tabs { padding: 0 6px; }
  .tabcon { padding: 16px 14px; }
  .detail-top { padding: 16px 14px; }
  .buyrow .btn { flex: 1 1 100%; }
  .cart-total-bar { flex-wrap: wrap; gap: 10px; justify-content: center; text-align: center; }

  .footer .cols { gap: 18px 22px; }
  .footer .cols > div { min-width: 42%; }
  .footer .qrs { flex-wrap: wrap; }
  .vip-strip { flex-wrap: wrap; gap: 8px 16px; }
  .notice-bar .wrap { font-size: 12px; }
}

/* ---------- 汉堡按钮 ---------- */
.nav-btn {
  position: absolute; right: 14px; top: 7px; z-index: 220;
  width: 46px; height: 38px; border: 1px solid rgba(255,255,255,.65); border-radius: 6px;
  background: rgba(255,255,255,.22); cursor: pointer; box-shadow: 0 2px 8px rgba(0,0,0,.18);
  flex-direction: column; align-items: center; justify-content: center; gap: 5px;
}
.nav-btn span { display: block; width: 20px; height: 2px; background: #fff; border-radius: 2px; transition: .25s; }
.nav.open .nav-btn span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav.open .nav-btn span:nth-child(2) { opacity: 0; }
.nav.open .nav-btn span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }
.nav { position: sticky; }
@keyframes navDrop { from { opacity: 0; transform: translateY(-8px); } to { opacity: 1; transform: none; } }