/* ========================================
   花卷留德 v4 — 粒子开场/真实地图/案例页/hover切换/板块过渡
   ======================================== */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
:root{--blue:#1E4DB7;--blue-light:#2a5dd7;--gold:#C8A96E;--bg:#FAFAFA;--text:#1A1A1A;--sub:#5A5A5A;--white:#fff;--radius:16px}
html{scroll-behavior:smooth;font-size:16px}
body{font-family:-apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei",sans-serif;background:var(--bg);color:var(--text);line-height:1.7;-webkit-font-smoothing:antialiased;overflow-x:hidden}
a{color:inherit;text-decoration:none}img{max-width:100%}
.container{max-width:1200px;margin:0 auto;padding:0 24px}
::selection{background:rgba(30,77,183,.12);color:var(--blue)}

/* 无障碍 */
@media(prefers-reduced-motion:reduce){*,*::before,*::after{animation-duration:.01ms!important;animation-iteration-count:1!important;transition-duration:.01ms!important}}

/* 网格纹理 */
body::before{content:"";position:fixed;inset:0;z-index:-1;pointer-events:none;opacity:.03;
  background-image:linear-gradient(#1E4DB7 1px,transparent 1px),linear-gradient(90deg,#1E4DB7 1px,transparent 1px);
  background-size:40px 40px}

/* ===== 开场动画 ===== */
.intro-overlay{position:fixed;inset:0;z-index:9999;background:#fff;display:flex;align-items:center;justify-content:center;flex-direction:column;transition:opacity .5s,visibility .5s}
.intro-overlay.hidden{opacity:0;visibility:hidden;pointer-events:none}
.intro-logo{font-size:2.6rem;font-weight:300;letter-spacing:.2em;z-index:2;position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);transition:all .8s cubic-bezier(.4,0,.2,1)}
.intro-logo.nav-pos{top:22px;left:28px;transform:translate(0,0);font-size:1.1rem;letter-spacing:.05em;font-weight:400}
.intro-slogan{font-size:.9rem;color:var(--gold);letter-spacing:.3em;opacity:0;transition:opacity .5s;z-index:2}
.intro-slogan .char{display:inline-block;opacity:0;transition:opacity .3s}
.intro-light{position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);width:0;height:0;border-radius:50%;background:radial-gradient(circle,rgba(30,77,183,.08),transparent 70%);transition:all .7s ease-out;z-index:1}
.intro-light.expand{width:800px;height:800px}
.intro-particles{position:absolute;inset:0;pointer-events:none;z-index:0}
.intro-particle{position:absolute;border-radius:50%}

/* ===== 导航 ===== */
.nav{position:fixed;top:0;left:0;right:0;z-index:100;padding:16px 28px;display:flex;align-items:center;justify-content:space-between;transition:all .4s}
.nav.scrolled{background:rgba(255,255,255,.88);backdrop-filter:blur(16px);-webkit-backdrop-filter:blur(16px);box-shadow:0 1px 3px rgba(0,0,0,.05)}
.nav-logo{font-size:1.1rem;font-weight:400;letter-spacing:.05em;opacity:0;transition:opacity .4s}
.nav-links{display:none;gap:28px;align-items:center}
.nav-links a{font-size:.9rem;color:var(--sub);transition:color .25s;position:relative;padding-bottom:4px;opacity:0}
.nav-links a::after{content:"";position:absolute;bottom:0;left:0;width:0;height:2px;background:var(--gold);border-radius:1px;transition:width .3s cubic-bezier(.16,1,.3,1)}
.nav-links a:hover{color:var(--blue)}
.nav-links a:hover::after,.nav-links a.active::after{width:100%}
.nav-cta{background:var(--blue);color:#fff;padding:9px 22px;border-radius:24px;font-size:.9rem;font-weight:500;display:none;transition:all .3s;opacity:0}
.nav-cta:hover{background:var(--blue-light);box-shadow:0 0 0 6px rgba(30,77,183,.1)}
@media(min-width:768px){.nav-links,.nav-cta{display:flex}}
.nav-menu-item.visible,.nav-cta.visible{opacity:1!important;transition:opacity .3s}

/* ===== Hero ===== */
.hero{min-height:100vh;display:flex;align-items:center;background:linear-gradient(135deg,rgba(232,240,254,.3),var(--bg));position:relative;overflow:hidden}
.hero-blobs{position:absolute;inset:0;pointer-events:none;z-index:0}
.hero-blob{position:absolute;border-radius:50%;background:radial-gradient(circle,rgba(30,77,183,.05),transparent 70%)}
.hero-grid{display:grid;grid-template-columns:1fr;gap:32px;align-items:center;padding-top:80px;padding-bottom:60px;width:100%;position:relative;z-index:1}
@media(min-width:768px){.hero-grid{grid-template-columns:3fr 2fr}}
.hero-tag{display:inline-block;background:rgba(255,255,255,.7);border:1px solid rgba(30,77,183,.1);border-radius:24px;padding:6px 18px;font-size:.8rem;color:var(--blue);margin-bottom:20px}
.hero-title{font-size:clamp(2.2rem,5.5vw,3.6rem);font-weight:300;line-height:1.18;letter-spacing:-.01em;margin-bottom:16px}
.hero-sub{font-size:1.05rem;color:var(--sub);margin-bottom:12px;max-width:400px}
.hero-sub::after{content:"";display:block;width:60px;height:1.5px;background:var(--gold);margin-top:12px}
.hero-btns{display:flex;flex-wrap:wrap;gap:12px;margin-bottom:18px}
.btn-primary{background:var(--blue);color:#fff;padding:14px 32px;border-radius:28px;font-size:1rem;font-weight:500;border:none;cursor:pointer;transition:all .35s;display:inline-block;text-align:center}
.btn-primary:hover{background:var(--blue-light);transform:translateY(-1px)}
.btn-outline{border:1px solid rgba(30,77,183,.2);color:var(--blue);padding:14px 32px;border-radius:28px;font-size:1rem;font-weight:500;transition:all .35s;display:inline-block;text-align:center}
.btn-outline:hover{background:rgba(30,77,183,.04)}
.hero-note{font-size:.9rem;color:var(--sub)}
.hero-map-wrap{display:none;position:relative;justify-content:center;align-items:center}
@media(min-width:768px){.hero-map-wrap{display:flex}}
.hero-map-wrap svg{width:300px;height:360px}
.map-label{position:absolute;bottom:8px;right:16px;font-size:10px;color:#ccc;letter-spacing:.1em}

/* ===== Sections ===== */
.section{padding:80px 0}
.section-white{background:var(--white)}
.section-tint{background:linear-gradient(180deg,var(--bg),rgba(232,240,254,.2))}
.section-header{text-align:center;margin-bottom:48px}
.section-title{font-size:clamp(1.8rem,3.5vw,2.3rem);font-weight:300;letter-spacing:-.01em;margin-bottom:8px}
.section-sub{color:var(--sub)}
.sec-reveal{opacity:0;transform:translateY(60px);transition:opacity .8s ease-out,transform .8s ease-out}
.sec-reveal.visible{opacity:1;transform:translateY(0)}

/* ===== 数据 ===== */
.data-row{display:flex;justify-content:center;gap:36px 56px;flex-wrap:wrap;text-align:center}
.data-num{font-size:3.2rem;font-weight:300}
.data-num.blue{color:var(--blue)}
.data-num.grad{background:linear-gradient(135deg,var(--blue),var(--gold));-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}
.data-label{color:var(--sub);margin-top:4px;font-size:.95rem}

/* ===== 卡片 ===== */
.cards{display:grid;gap:20px}
@media(min-width:768px){.cards-3{grid-template-columns:repeat(3,1fr)}}
@media(min-width:640px){.cards-4{grid-template-columns:repeat(2,1fr)}}
@media(min-width:900px){.cards-4{grid-template-columns:repeat(4,1fr)}}
.card{background:var(--white);border-radius:12px;padding:32px 28px;box-shadow:0 2px 12px rgba(0,0,0,.03);transition:all .5s cubic-bezier(.34,1.56,.64,1);cursor:default}
.card:hover{transform:translateY(-6px);box-shadow:0 20px 48px rgba(0,0,0,.08)}
.card-tag{font-size:.75rem;color:var(--blue);font-weight:500;margin-bottom:12px;transition:color .3s}
.card:hover .card-tag{color:var(--blue)}
.card-desc{font-size:.9rem;color:var(--sub);line-height:1.7}
.card-quote{border-top:1px solid #eee;margin-top:16px;padding-top:14px;font-size:.88rem;color:var(--sub);font-style:italic;line-height:1.65}
.trust-card{text-align:center;padding:36px 24px;position:relative}
.trust-card::after{content:"";position:absolute;right:0;top:20%;height:60%;width:1px;background:#E0E0E0}
.trust-card:last-child::after{display:none}
.trust-icon{width:48px;height:48px;background:rgba(30,77,183,.06);border-radius:12px;display:flex;align-items:center;justify-content:center;margin:0 auto 16px;font-size:1.3rem}
.trust-title{font-weight:500;margin-bottom:6px;font-size:1rem}
.trust-desc{font-size:.85rem;color:var(--sub);line-height:1.6}

/* ===== 服务 ===== */
.service-tags{display:flex;flex-wrap:wrap;justify-content:center;gap:10px;margin-bottom:32px}
.service-tag{padding:10px 24px;border-radius:24px;font-size:.9rem;font-weight:500;border:none;cursor:pointer;transition:all .3s;background:#eee;color:var(--sub)}
.service-tag:hover,.service-tag.active{background:var(--blue);color:#fff}
.service-panel{max-width:560px;margin:0 auto;color:var(--sub);line-height:1.8;font-size:.95rem;display:none;opacity:0;transition:opacity .25s}
.service-panel.active{display:block;opacity:1}

/* ===== CTA ===== */
.cta-section{text-align:center;padding:100px 0}
.cta-title{font-size:clamp(1.8rem,4vw,2.4rem);font-weight:300;margin-bottom:28px}
.cta-btn{display:inline-block;background:var(--blue);color:#fff;padding:16px 44px;border-radius:30px;font-size:1.1rem;font-weight:500;transition:all .35s;border:none;cursor:pointer}
.cta-btn:hover{background:var(--gold)}

/* ===== 案例页 ===== */
.cases-hero{background:linear-gradient(180deg,#E8F0FE,var(--bg));padding:100px 0 60px;text-align:center}
.cases-filters{display:flex;flex-wrap:wrap;justify-content:center;gap:8px;margin-bottom:36px}
.cases-filter{padding:8px 18px;border-radius:20px;font-size:.85rem;font-weight:500;border:1px solid #ddd;cursor:pointer;background:#fff;color:var(--sub);transition:all .25s}
.cases-filter:hover{color:var(--blue);border-color:var(--blue)}
.cases-filter.active{color:var(--gold);border-color:var(--gold);border-bottom-width:2px}
.case-card-detail{cursor:pointer}

/* 模态框 */
.modal-overlay{position:fixed;inset:0;z-index:200;background:rgba(0,0,0,.4);display:flex;align-items:center;justify-content:center;opacity:0;visibility:hidden;transition:all .3s}
.modal-overlay.open{opacity:1;visibility:visible}
.modal-content{background:#fff;border-radius:16px;padding:40px;max-width:560px;width:90%;max-height:80vh;overflow-y:auto;position:relative;transform:translateY(20px);transition:transform .4s cubic-bezier(.16,1,.3,1)}
.modal-overlay.open .modal-content{transform:translateY(0)}
.modal-close{position:absolute;top:16px;right:20px;font-size:1.5rem;border:none;background:none;cursor:pointer;color:var(--sub);transition:color .2s}
.modal-close:hover{color:var(--text)}

/* ===== 回到顶部 ===== */
.back-to-top{position:fixed;bottom:32px;right:32px;z-index:90;width:44px;height:44px;border-radius:50%;background:var(--blue);color:#fff;border:none;cursor:pointer;font-size:1.2rem;transform:scale(0);transition:transform .35s cubic-bezier(.34,1.56,.64,1);box-shadow:0 4px 16px rgba(30,77,183,.25)}
.back-to-top.visible{transform:scale(1)}
.back-to-top:hover{background:var(--blue-light)}

/* ===== 页脚 ===== */
.footer{background:#2D2D2D;color:#fff;padding:48px 0;text-align:center}
.footer p{font-size:.88rem}
.footer .muted{color:#999;margin-top:6px;font-size:.82rem}

/* 响应式简化 */
@media(max-width:768px){
  .hero-blobs{display:none}
  .section{padding:56px 0}
}