/* ==========================================================================
   墨白互联 · service-seo.html 专属样式（SEO优化服务）
   布局指纹：F21 套环式（圆环相互交叠，环环相扣）
   模块：页首 Banner → 套环核心区 → 优化清单 → 五步流程 → 交付周期
         → 相关案例 → 配套服务 → FAQ → 套环 CTA
   ========================================================================== */

/* ===== 页首 Banner ===== */
.seo-hero{position:relative;min-height:480px;display:flex;align-items:center;overflow:hidden}
.seo-hero-bg{position:absolute;inset:0;width:100%;height:100%;object-fit:cover}
.seo-hero-mask{position:absolute;inset:0;background:linear-gradient(100deg,rgba(29,52,38,.8) 0%,rgba(29,52,38,.42) 55%,rgba(38,37,31,.12) 100%)}
.seo-hero-inner{position:relative;z-index:2;padding-block:clamp(76px,9vw,120px);color:var(--moon-100)}
.seo-hero .kicker{color:var(--moon-200)}
.seo-hero .kicker::before{background:var(--moon-200)}
.seo-hero h1{color:#fff;font-size:clamp(32px,4.6vw,54px);letter-spacing:.1em;line-height:1.3;margin-top:20px}
.seo-hero-sub{margin-top:20px;max-width:600px;color:rgba(247,245,238,.88);font-size:clamp(15px,1.5vw,18px);line-height:2}
.seo-hero-actions{margin-top:36px;display:flex;gap:16px;flex-wrap:wrap;align-items:center}
.seo-phone-btn svg{width:18px;height:18px;fill:currentColor}
.seo-crumb-wrap{padding-top:26px}

/* ===== F21 套环核心区 ===== */
.seo-rings{position:relative;display:flex;justify-content:center;align-items:flex-start;gap:0;margin-top:60px;flex-wrap:nowrap}
.seo-ring{position:relative;width:230px;background:var(--moon-50);border:2px solid var(--bamboo-500);
  border-radius:50%;aspect-ratio:1;display:flex;flex-direction:column;justify-content:center;align-items:center;
  text-align:center;padding:26px;z-index:2;transition:transform .3s ease,z-index 0s}
.seo-ring h3{font-size:19px;color:var(--bamboo-700);letter-spacing:.08em}
.seo-ring p{font-size:12.5px;color:var(--ink-500);line-height:1.8;margin-top:8px}
/* 交叠：每一环叠到前一环上 */
.seo-ring-1{margin-right:-48px;z-index:1}
.seo-ring-2{margin-right:-48px;z-index:2;background:var(--moon-200)}
.seo-ring-3{margin-right:-48px;z-index:1}
.seo-ring-4{z-index:2;background:var(--bamboo-700);border-color:var(--cinnabar-500)}
.seo-ring-4 h3{color:var(--moon-100)}
.seo-ring-4 p{color:rgba(247,245,238,.75)}
.seo-ring:hover{transform:translateY(-8px);z-index:5}

/* 适合谁 */
.seo-who{max-width:880px;margin:64px auto 0;background:var(--moon-50);border:1px solid var(--line-soft);
  border-radius:var(--radius);padding:30px 34px;box-shadow:var(--shadow-soft)}
.seo-who h3{font-size:20px;margin-bottom:14px}
.seo-who ul{display:grid;grid-template-columns:1fr 1fr;gap:10px 28px}
.seo-who li{position:relative;padding-left:22px;font-size:14.5px;color:var(--ink-700);line-height:1.9}
.seo-who li::before{content:"";position:absolute;left:0;top:.2em;width:12px;height:12px;border:2px solid var(--bamboo-500);
  border-radius:50%}

/* ===== 优化清单（环形描边条目） ===== */
.seo-detail-sec{background:var(--moon-200)}
.seo-detail-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:22px;margin-top:44px}
.seo-d-item{background:var(--moon-50);border:1px solid var(--line-soft);border-radius:var(--radius);padding:26px 24px;
  position:relative;transition:transform .3s ease,box-shadow .3s ease}
.seo-d-item:hover{transform:translateY(-6px);box-shadow:var(--shadow-lift)}
.seo-d-item h3{font-size:18.5px;letter-spacing:.05em;padding-left:16px;border-left:3px solid var(--cinnabar-500)}
.seo-d-item p{margin-top:12px;font-size:14px;color:var(--ink-500);line-height:1.9}

/* ===== 流程简版 5 步（环串） ===== */
.seo-flow{display:flex;gap:0;margin-top:48px;align-items:stretch}
.seo-flow li{flex:1;background:var(--moon-50);border:1px solid var(--line-soft);padding:24px 18px 22px;
  margin-right:-1px;text-align:center;position:relative}
.seo-flow-num{display:inline-flex;width:44px;height:44px;align-items:center;justify-content:center;border-radius:50%;
  border:2px solid var(--bamboo-500);color:var(--bamboo-700);font-family:var(--serif);font-weight:700;background:var(--moon-100)}
.seo-flow h3{font-size:16.5px;margin-top:12px}
.seo-flow p{font-size:13px;color:var(--ink-500);line-height:1.8;margin-top:6px}

/* ===== 交付 / 周期 ===== */
.seo-deliver{background:var(--moon-100);border-top:1px solid var(--line-soft)}
.seo-deliver-inner{display:grid;grid-template-columns:1.2fr 1fr;gap:clamp(28px,5vw,70px);align-items:center;
  padding-block:clamp(44px,6vw,72px)}
.seo-deliver-text p{margin-top:16px;font-size:14.5px;line-height:2;color:var(--ink-700)}
.seo-deliver-img{border-radius:var(--radius);box-shadow:var(--shadow-lift);width:100%;aspect-ratio:3/2;object-fit:cover}

/* ===== 相关案例 ===== */
.seo-case-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:22px;margin-top:44px}
.seo-case{border-radius:var(--radius);overflow:hidden;background:var(--moon-50);border:1px solid var(--line-soft);
  transition:transform .3s ease,box-shadow .3s ease}
.seo-case:hover{transform:translateY(-6px);box-shadow:var(--shadow-lift)}
.seo-case img{width:100%;aspect-ratio:3/2;object-fit:cover}
.seo-case-body{padding:18px 20px}
.seo-case-body h3{font-size:17px}
.seo-case-body p{font-size:13.5px;color:var(--ink-500);line-height:1.8;margin-top:6px}

/* ===== 配套服务互链 ===== */
.seo-relate{background:var(--moon-200)}
.seo-relate-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:16px;margin-top:40px}
.seo-relate-grid a{display:flex;flex-direction:column;gap:4px;padding:22px;background:var(--moon-50);
  border:1px solid var(--line-soft);border-radius:50% 50% 12px 12px/24px 24px 12px 12px;font-family:var(--serif);
  font-size:16.5px;letter-spacing:.05em;color:var(--ink-900)}
.seo-relate-grid a span{font-family:var(--sans);font-size:13px;color:var(--ink-500);letter-spacing:0}
.seo-relate-grid a:hover{border-color:var(--cinnabar-500);transform:translateY(-3px)}

/* ===== FAQ（圆环编号问答） ===== */
.seo-faq{max-width:960px;margin:44px auto 0;display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.seo-faq-item{background:var(--moon-50);border:1px solid var(--line-soft);border-radius:var(--radius);padding:26px 24px}
.seo-faq-item h3{font-size:16.5px;line-height:1.6;padding-top:38px;position:relative}
.seo-faq-item h3::before{content:"问";position:absolute;left:0;top:0;width:32px;height:32px;border-radius:50%;
  background:var(--cinnabar-500);color:#FFF3EC;display:flex;align-items:center;justify-content:center;
  font-family:var(--serif);font-size:14px}
.seo-faq-item p{margin-top:10px;font-size:14px;color:var(--ink-500);line-height:1.95}

/* ===== CTA（同心环） ===== */
.seo-cta{position:relative;overflow:hidden;background:
  radial-gradient(700px 360px at 50% 120%,rgba(192,47,43,.22),transparent 60%),var(--bamboo-900)}
.seo-cta-inner{position:relative;text-align:center;padding-block:clamp(56px,8vw,88px)}
.seo-cta-ringwrap{position:absolute;left:50%;top:50%;transform:translate(-50%,-50%);pointer-events:none}
.seo-cta-ring-1{position:absolute;left:50%;top:50%;width:360px;height:360px;transform:translate(-50%,-50%);
  border:1.5px solid rgba(247,245,238,.14);border-radius:50%}
.seo-cta-ring-2{position:absolute;left:50%;top:50%;width:520px;height:520px;transform:translate(-50%,-50%);
  border:1.5px dashed rgba(192,47,43,.28);border-radius:50%}
.seo-cta h2{color:var(--moon-100);font-size:clamp(26px,3.2vw,38px);letter-spacing:.08em;position:relative}
.seo-cta p{margin-top:12px;color:rgba(247,245,238,.7);font-size:15px;position:relative}
.seo-cta-btn{margin-top:28px;position:relative}

/* ===== 响应式 ===== */
@media (max-width:1080px){
  .seo-rings{flex-wrap:wrap;gap:16px}
  .seo-ring{margin:0 !important;border-radius:var(--radius);aspect-ratio:auto;width:calc(50% - 8px)}
  .seo-detail-grid{grid-template-columns:1fr 1fr}
  .seo-flow{flex-wrap:wrap}
  .seo-flow li{flex:1 1 33%}
  .seo-deliver-inner{grid-template-columns:1fr}
  .seo-case-grid{grid-template-columns:1fr 1fr}
  .seo-faq{grid-template-columns:1fr}
  .seo-relate-grid{grid-template-columns:1fr 1fr}
}
@media (max-width:640px){
  .seo-rings{flex-direction:column;align-items:stretch}
  .seo-ring{width:auto;border-radius:var(--radius)}
  .seo-detail-grid{grid-template-columns:1fr}
  .seo-flow{flex-direction:column}
  .seo-case-grid{grid-template-columns:1fr}
  .seo-relate-grid{grid-template-columns:1fr}
  .seo-who ul{grid-template-columns:1fr}
  .seo-hero{min-height:400px}
  .seo-cta-ring-2{width:320px;height:320px}
}