/* ============================================================
   beikao.css · 备考题库总览（hub）
   题头形态①：全幅图 Banner + 居中标题
   区块：时间轴 / 方法卡 + 图 / 8 卡题库入口 / 真题图带 / 考前提醒 zigzag / FAQ / CTA
   ============================================================ */

/* ---------- 题头：全幅 Banner ---------- */
.bk-hero{
  position:relative; min-height:560px; display:flex; align-items:center;
  padding:120px 0 72px; overflow:hidden;
}
.bk-hero-bg{
  position:absolute; inset:0; width:100%; height:100%; object-fit:cover;
}
.bk-hero-mask{
  position:absolute; inset:0;
  background:linear-gradient(180deg, rgba(15,31,23,.72) 0%, rgba(15,31,23,.52) 55%, rgba(15,31,23,.78) 100%);
}
.bk-hero-inner{ position:relative; text-align:center; color:#fff; }
.bk-crumbs{ display:flex; justify-content:center; flex-wrap:wrap; gap:8px; font-size:13px; color:rgba(255,255,255,.72); margin-bottom:18px; }
.bk-crumbs a{ color:rgba(255,255,255,.85); }
.bk-crumbs a:hover{ color:var(--orange-2); }
.bk-crumbs .sep{ color:rgba(255,255,255,.4); }
.bk-kicker{
  display:inline-block; font-size:13px; font-weight:700; letter-spacing:3px;
  color:#fff; background:rgba(255,122,28,.9); padding:6px 16px; border-radius:999px; margin-bottom:18px;
}
.bk-title{ font-size:46px; font-weight:800; line-height:1.25; letter-spacing:1px; }
.bk-sub{ max-width:760px; margin:18px auto 0; font-size:16px; line-height:1.9; color:rgba(255,255,255,.9); }
.bk-actions{ margin-top:28px; display:flex; justify-content:center; flex-wrap:wrap; gap:14px; }
.bk-tags{ margin-top:30px; display:flex; justify-content:center; flex-wrap:wrap; gap:10px; }
.bk-tags li{
  font-size:13px; font-weight:600; color:#fff; padding:7px 16px; border-radius:999px;
  border:1px solid rgba(255,255,255,.35); background:rgba(255,255,255,.08); backdrop-filter:blur(4px);
}

/* ---------- 时间轴 ---------- */
.bk-tl{ background:var(--bg-soft); }
.bk-tl-wrap{ position:relative; margin-top:44px; }
.bk-tl-wrap::before{
  content:""; position:absolute; top:0; bottom:0; left:50%; width:3px; transform:translateX(-50%);
  background:linear-gradient(180deg, var(--orange), var(--green)); border-radius:3px;
}
.bk-tl-list{ position:relative; }
.bk-tl-list li{ position:relative; width:50%; padding:0 44px 36px 0; }
.bk-tl-list li:nth-child(even){ margin-left:50%; padding:0 0 36px 44px; }
.bk-tl-dot{
  position:absolute; top:4px; right:-27px; width:54px; height:54px; border-radius:50%;
  display:flex; align-items:center; justify-content:center; font-weight:800; font-size:15px; color:#fff;
  background:linear-gradient(135deg, var(--orange), var(--orange-deep)); box-shadow:0 8px 18px rgba(255,122,28,.35);
  z-index:2;
}
.bk-tl-list li:nth-child(even) .bk-tl-dot{ right:auto; left:-27px; background:linear-gradient(135deg, var(--green), var(--green-deep)); box-shadow:0 8px 18px rgba(18,183,106,.32); }
.bk-tl-card{
  background:#fff; border-radius:var(--radius); padding:22px 24px; box-shadow:var(--shadow-sm);
  border-top:4px solid var(--orange);
}
.bk-tl-list li:nth-child(even) .bk-tl-card{ border-top-color:var(--green); }
.bk-tl-card h3{ font-size:17px; margin-bottom:8px; }
.bk-tl-card p{ font-size:14.5px; color:var(--ink-2); line-height:1.85; }

/* ---------- 备考方法 ---------- */
.bk-m-grid{ display:grid; grid-template-columns:repeat(3,1fr); gap:22px; margin-top:36px; }
.bk-m-card{
  background:#fff; border:1px solid var(--line); border-radius:var(--radius-lg); padding:28px 26px;
  box-shadow:var(--shadow-sm); transition:transform .3s ease, box-shadow .3s ease;
}
.bk-m-card:hover{ transform:translateY(-6px); box-shadow:var(--shadow-md); }
.bk-m-num{
  display:inline-flex; width:44px; height:44px; border-radius:12px; align-items:center; justify-content:center;
  font-weight:800; font-size:17px; color:#fff; background:linear-gradient(135deg,var(--green),var(--green-deep)); margin-bottom:16px;
}
.bk-m-card:nth-child(2) .bk-m-num{ background:linear-gradient(135deg,var(--orange),var(--orange-deep)); }
.bk-m-card h3{ font-size:18px; margin-bottom:10px; }
.bk-m-card p{ font-size:14.5px; color:var(--ink-2); line-height:1.85; }
.bk-m-photo{ margin-top:40px; border-radius:var(--radius-lg); overflow:hidden; box-shadow:var(--shadow-md); }
.bk-m-photo img{ width:100%; height:280px; object-fit:cover; }
.bk-m-photo figcaption{
  background:var(--ink); color:#cfe3d8; font-size:13.5px; padding:12px 20px; letter-spacing:.5px;
}

/* ---------- 题库 8 卡 ---------- */
.bk-grid{ background:var(--bg-orange); }
.bk-g-grid{ display:grid; grid-template-columns:repeat(4,1fr); gap:18px; margin-top:36px; }
.bk-g-card{
  position:relative; background:#fff; border-radius:var(--radius); padding:24px 20px 20px;
  box-shadow:var(--shadow-sm); display:flex; flex-direction:column; gap:8px; overflow:hidden;
  transition:transform .3s ease, box-shadow .3s ease;
}
.bk-g-card::before{
  content:""; position:absolute; top:0; left:0; right:0; height:5px;
}
.bk-g-card.g-orange::before{ background:linear-gradient(90deg,var(--orange),var(--orange-2)); }
.bk-g-card.g-green::before{ background:linear-gradient(90deg,var(--green),var(--green-2)); }
.bk-g-card:hover{ transform:translateY(-6px); box-shadow:var(--shadow-md); }
.bk-g-no{ font-size:13px; font-weight:800; letter-spacing:2px; color:var(--ink-3); }
.bk-g-card b{ font-size:18px; }
.bk-g-card p{ font-size:13.5px; color:var(--ink-2); line-height:1.7; flex:1; }
.bk-g-more{ font-style:normal; font-size:13.5px; font-weight:700; color:var(--orange-deep); }
.bk-g-card.g-green .bk-g-more{ color:var(--green-deep); }
.bk-inline-link{ color:var(--green-deep); font-weight:700; border-bottom:1px dashed var(--green); }
.bk-inline-link:hover{ color:var(--orange-deep); }

/* ---------- 真题图带 ---------- */
.bk-zhenti{ position:relative; overflow:hidden; }
.bk-zhenti-bg{ position:absolute; inset:0; width:100%; height:100%; object-fit:cover; }
.bk-zhenti-mask{ position:absolute; inset:0; background:linear-gradient(90deg, rgba(11,143,86,.92) 0%, rgba(11,143,86,.78) 55%, rgba(15,31,23,.55) 100%); }
.bk-zhenti-inner{ position:relative; padding:80px 0; }
.bk-zhenti-copy{ max-width:620px; color:#fff; }
.bk-zhenti-kicker{ font-size:13px; font-weight:700; letter-spacing:3px; margin-bottom:12px; color:#d8ffe9; }
.bk-zhenti-copy h2{ font-size:32px; font-weight:800; line-height:1.4; margin-bottom:16px; }
.bk-zhenti-copy p{ font-size:15px; line-height:1.9; color:rgba(255,255,255,.92); margin-bottom:26px; }

/* ---------- 考前提醒 ---------- */
.bk-kaoqian{ background:var(--bg-green); }
.bk-kq-grid{ display:grid; grid-template-columns:1fr 1.2fr; gap:48px; align-items:start; }
.bk-kq-list{ display:flex; flex-direction:column; gap:16px; }
.bk-kq-list li{
  display:flex; gap:16px; background:#fff; border-radius:var(--radius); padding:18px 20px;
  box-shadow:var(--shadow-sm);
}
.bk-kq-ic{
  flex-shrink:0; width:44px; height:44px; border-radius:12px; display:flex; align-items:center; justify-content:center;
  font-weight:800; color:#fff; background:linear-gradient(135deg,var(--orange),var(--orange-deep));
}
.bk-kq-list li:nth-child(even) .bk-kq-ic{ background:linear-gradient(135deg,var(--green),var(--green-deep)); }
.bk-kq-list b{ font-size:15.5px; }
.bk-kq-list p{ font-size:14px; color:var(--ink-2); margin-top:4px; line-height:1.75; }

/* ---------- FAQ 手风琴 ---------- */
.bk-faq-wrap{ max-width:860px; margin:36px auto 0; }
.acc-item{
  background:#fff; border:1px solid var(--line); border-radius:var(--radius); margin-bottom:14px; overflow:hidden;
}
.acc-head{
  width:100%; text-align:left; padding:18px 22px; font-size:16px; font-weight:700; color:var(--ink);
  display:flex; justify-content:space-between; align-items:center; gap:14px;
}
.acc-head::after{
  content:"+"; flex-shrink:0; width:30px; height:30px; border-radius:50%;
  display:flex; align-items:center; justify-content:center; font-size:18px; font-weight:700;
  background:var(--orange-soft); color:var(--orange-deep); transition:transform .3s ease, background .3s ease;
}
.acc-item.open .acc-head::after{ transform:rotate(45deg); background:var(--green-soft); color:var(--green-deep); }
.acc-panel{ display:none; padding:0 22px 20px; }
.acc-item.open .acc-panel{ display:block; }
.acc-panel p{ font-size:14.5px; color:var(--ink-2); line-height:1.9; }

/* ---------- 底部 CTA ---------- */
.bk-cta{
  background:linear-gradient(120deg, var(--orange-deep) 0%, var(--orange) 55%, var(--green-deep) 130%);
}
.bk-cta-inner{
  display:grid; grid-template-columns:1.4fr 1fr; gap:32px; align-items:center;
  padding:64px 0; color:#fff;
}
.bk-cta-copy h2{ font-size:30px; font-weight:800; margin-bottom:12px; }
.bk-cta-copy p{ font-size:15px; line-height:1.9; color:rgba(255,255,255,.92); max-width:560px; }
.bk-cta-act{ display:flex; flex-wrap:wrap; gap:14px; justify-content:flex-end; }

/* ---------- 响应式 ---------- */
@media (max-width:980px){
  .bk-title{ font-size:34px; }
  .bk-m-grid{ grid-template-columns:1fr; }
  .bk-g-grid{ grid-template-columns:repeat(2,1fr); }
  .bk-kq-grid{ grid-template-columns:1fr; gap:28px; }
  .bk-cta-inner{ grid-template-columns:1fr; }
  .bk-cta-act{ justify-content:flex-start; }
  .bk-tl-wrap::before{ left:27px; }
  .bk-tl-list li, .bk-tl-list li:nth-child(even){ width:100%; margin-left:0; padding:0 0 30px 64px; }
  .bk-tl-dot, .bk-tl-list li:nth-child(even) .bk-tl-dot{ left:0; right:auto; }
}
@media (max-width:640px){
  .bk-hero{ min-height:480px; padding:110px 0 56px; }
  .bk-title{ font-size:28px; }
  .bk-g-grid{ grid-template-columns:1fr; }
  .bk-zhenti-copy h2{ font-size:24px; }
}