/* ============================================================
   zizhi-biangeng.css —— 资质变更页
   hero:对称 V 谷底缘;变更情形表;墨黑横向四步;
   雷区咬合;材料四宫格;案例;FAQ。
   ============================================================ */

/* ---------- Hero:对称 V 谷 ---------- */
.bg-hero{
  margin-top:var(--nav-h);
  background:
    linear-gradient(120deg, rgba(28,26,23,.88), rgba(74,55,40,.84)),
    url("../images/banner-zizhi.jpg") center/cover;
  color:var(--cream); padding:100px 0 150px;
  clip-path:polygon(0 0, 100% 0, 100% 90%, 50% 100%, 0 85%);
}
.bg-hero-in{ max-width:880px; }
.bg-keycap{ margin-bottom:22px; }
.bg-hero h1{ font-size:clamp(28px,4.2vw,50px); color:var(--cream); margin:12px 0 18px; }
.bg-sub{ font-size:16.5px; color:rgba(242,232,213,.88); max-width:740px; }
.bg-cta{ margin-top:28px; display:flex; flex-wrap:wrap; gap:14px; }
.bg-ghost{ border-color:rgba(242,232,213,.5); color:var(--cream); }
.bg-ghost:hover{ color:var(--tan); border-color:var(--tan); }

/* ---------- 通用 ---------- */
.bg-num{ font-family:var(--font-mono); font-size:13px; letter-spacing:4px; color:var(--brown-3); margin-bottom:10px; }
.bg-num-light{ font-family:var(--font-mono); font-size:13px; letter-spacing:4px; color:var(--tan); margin-bottom:10px; }
.bg-light-h{ color:var(--cream); }
.bg-note{ font-size:12.5px; color:var(--brown-3); margin-top:12px; }
.bg-table-wrap{ overflow-x:auto; }
.bg-tbl{ table-layout:fixed; }
.bg-tbl th,.bg-tbl td{ font-size:14px; }
.bg-tbl tbody tr:nth-child(even){ background:var(--paper-2); }

/* ---------- 板块 2:情形表 ---------- */
.bg-when{ padding:70px 0; background:var(--paper); }
.bg-when h2{ font-size:clamp(22px,2.6vw,32px); margin-bottom:24px; }

/* ---------- 板块 3:流程(墨黑横向) ---------- */
.bg-flow{ background:var(--ink); color:rgba(242,232,213,.88); padding:80px 0; }
.bg-flow h2{ font-size:clamp(22px,2.6vw,32px); color:var(--cream); margin-bottom:28px; }
.bg-steps{ display:grid; grid-template-columns:repeat(4,1fr); gap:18px; }
.bg-step{
  border:1px dashed rgba(242,232,213,.25); border-radius:var(--r-m); padding:22px 18px;
}
.bg-step span{
  display:inline-flex; width:36px; height:36px; border-radius:50%;
  background:var(--tan); color:var(--ink); font-family:var(--font-mono);
  align-items:center; justify-content:center; margin-bottom:12px; font-weight:700;
}
.bg-step h3{ color:var(--cream); font-size:16.5px; margin-bottom:6px; }
.bg-step p{ font-size:13.5px; color:rgba(242,232,213,.72); }

/* ---------- 板块 4:雷区 ---------- */
.bg-pit{ padding:70px 0; background:var(--paper-2); }
.bg-pit-grid{ display:grid; grid-template-columns:1.1fr 1fr; gap:50px; align-items:center; }
.bg-pit-txt h2{ font-size:clamp(22px,2.4vw,30px); margin-bottom:16px; }
.bg-pit-list{ margin:0; }
.bg-pit-list li{
  padding:12px 0 12px 26px; border-bottom:1px dashed var(--line); position:relative; color:var(--ink-2);
}
.bg-pit-list li::before{
  content:"!"; position:absolute; left:0; top:12px;
  width:18px; height:18px; border-radius:50%; background:var(--brown); color:var(--cream);
  font-family:var(--font-mono); font-size:12px; display:flex; align-items:center; justify-content:center;
}
.bg-pit-list b{ color:var(--ink); }
.bg-pit-list a{ color:var(--brown-2); text-decoration:underline; }
.bg-pit-img img{
  border-radius:var(--r-l); box-shadow:var(--shadow);
  clip-path:polygon(0 0, 100% 0, 94% 100%, 0 92%);
}

/* ---------- 板块 5:材料(墨黑) ---------- */
.bg-mat{ background:var(--ink); color:rgba(242,232,213,.88); padding:80px 0; }
.bg-mat h2{ font-size:clamp(22px,2.6vw,32px); color:var(--cream); margin-bottom:28px; }
.bg-mat-grid{ display:grid; grid-template-columns:repeat(2,1fr); gap:18px; }
.bg-mat-i{
  background:var(--ink-2); border:1px solid rgba(242,232,213,.14);
  border-radius:var(--r-m); padding:20px 22px;
}
.bg-mat-i b{ display:block; font-family:var(--font-head); font-size:17px; color:var(--tan); margin-bottom:8px; }
.bg-mat-i p{ font-size:14px; color:rgba(242,232,213,.74); }

/* ---------- 板块 6:案例 ---------- */
.bg-case{ padding:70px 0; background:var(--paper); }
.bg-case-grid{ display:grid; grid-template-columns:1fr 1.1fr; gap:50px; align-items:center; }
.bg-case-img img{
  border-radius:var(--r-l); box-shadow:var(--shadow);
  clip-path:polygon(6% 0, 100% 8%, 100% 100%, 0 94%);
}
.bg-case-txt h2{ font-size:clamp(22px,2.4vw,30px); margin-bottom:14px; }
.bg-case-txt p{ color:var(--ink-2); }
.bg-case-txt a{ color:var(--brown-2); text-decoration:underline; }

/* ---------- 板块 7:FAQ ---------- */
.bg-faq{ padding:60px 0 80px; background:var(--paper-2); }
.bg-faq h2{ font-size:clamp(22px,2.6vw,32px); margin-bottom:24px; }
.bg-faq-list{ max-width:860px; }
.bg-faq-i{
  background:var(--paper); border:1px solid var(--line); border-radius:var(--r-m);
  margin-bottom:12px; overflow:hidden;
}
.bg-faq-i summary{
  cursor:pointer; padding:15px 20px; font-weight:600; color:var(--ink);
  list-style:none; position:relative; padding-right:40px;
}
.bg-faq-i summary::-webkit-details-marker{ display:none; }
.bg-faq-i summary::after{
  content:"+"; position:absolute; right:18px; top:50%; transform:translateY(-50%);
  font-family:var(--font-mono); font-size:20px; color:var(--brown-3);
}
.bg-faq-i[open] summary::after{ content:"–"; }
.bg-faq-i p{ padding:0 20px 16px; color:var(--ink-2); font-size:14.5px; }
.bg-faq-i p a{ color:var(--brown-2); text-decoration:underline; }

/* ---------- 板块 8:CTA ---------- */
.bg-cta{
  background:
    linear-gradient(110deg, rgba(74,55,40,.92), rgba(28,26,23,.9)),
    url("../images/scene-hetong.jpg") center/cover;
  color:var(--cream); padding:80px 0; text-align:center;
  clip-path:polygon(0 10%, 100% 0, 100% 100%, 0 100%);
}
.bg-cta h2{ color:var(--cream); font-size:clamp(22px,3vw,34px); margin-bottom:14px; }
.bg-cta p{ max-width:680px; margin:0 auto 24px; color:rgba(242,232,213,.85); }
.bg-cta-row{ display:flex; flex-wrap:wrap; gap:14px; justify-content:center; }
.bg-cta-links{ margin-top:22px; font-size:13.5px; color:rgba(242,232,213,.7); }
.bg-cta-links a{ color:var(--tan); text-decoration:underline; }

/* ---------- 响应式 ---------- */
@media (max-width:1080px){
  .bg-steps{ grid-template-columns:1fr 1fr; }
  .bg-pit-grid,.bg-case-grid{ grid-template-columns:1fr; gap:30px; }
  .bg-mat-grid{ grid-template-columns:1fr; }
}
@media (max-width:640px){
  .bg-steps{ grid-template-columns:1fr; }
  .bg-hero{ padding:70px 0 110px; }
}

/* ---------- 表格列宽(替代内联 style) ---------- */
.w24{ width:24%; }
.w40{ width:40%; }
.w36{ width:36%; }

/* ---------- 板块 6.5:变更期间衔接 ---------- */
.bg-live{ padding:60px 0; background:var(--paper-2); }
.bg-live h2{ font-size:clamp(22px,2.6vw,32px); margin-bottom:18px; }
.bg-live p{ font-size:15.5px; line-height:1.9; color:var(--ink-2); margin-bottom:14px; max-width:880px; }
.bg-live p b{ color:var(--ink); }
.bg-live p a{ color:var(--brown-2); text-decoration:underline; }

/* ---------- 板块 6.8:变更顺序(新增二轮) ---------- */
.bg-order{ padding:60px 0; background:var(--paper); }
.bg-order h2{ font-size:clamp(22px,2.6vw,32px); margin-bottom:18px; }
.bg-order > p{ font-size:15.5px; line-height:1.9; color:var(--ink-2); margin-bottom:18px; max-width:880px; }
.bg-order > p a{ color:var(--brown-2); text-decoration:underline; }
.bg-order-grid{ display:grid; grid-template-columns:repeat(2,1fr); gap:16px; margin-bottom:18px; }
.bg-order-i{
  background:var(--paper-2); border:1px solid var(--line); border-radius:var(--r-s);
  padding:18px 20px; border-left:4px solid var(--brown-2);
}
.bg-order-i span{ font-family:var(--font-mono); font-size:12px; color:var(--brown-3); letter-spacing:2px; }
.bg-order-i h3{ font-size:16px; margin:6px 0 6px; }
.bg-order-i p{ font-size:14px; color:var(--ink-2); line-height:1.8; }
@media (max-width:820px){ .bg-order-grid{ grid-template-columns:1fr; } }