/* ===========================================================
   LogicStorm 官网 · 极简黑白灰主题
   修改提示：颜色集中在 :root 变量，改这里即可全局换色
   =========================================================== */
:root{
  --bg:        #ffffff;
  --bg-alt:    #f6f6f5;
  --bg-dark:   #0e0e0e;
  --ink:       #111111;
  --ink-soft:  #5c5c5c;
  --ink-faint: #8a8a8a;
  --line:      #e4e4e2;
  --line-soft: #efefed;
  --accent:    #111111;
  --maxw:      1180px;
  --radius:    14px;
  --ease:      cubic-bezier(.22,.61,.36,1);
}

*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",Roboto,Helvetica,Arial,sans-serif;
  color:var(--ink);
  background:var(--bg);
  line-height:1.7;
  -webkit-font-smoothing:antialiased;
  font-size:16px;
}
img{max-width:100%;display:block}
a{color:inherit;text-decoration:none}
button{font-family:inherit;cursor:pointer;border:none;background:none}
.wrap{width:100%;max-width:var(--maxw);margin:0 auto;padding:0 24px}
.muted{color:var(--ink-soft)}
.center{text-align:center}

/* ---------- 语言切换：默认中文，html.en 显示英文 ---------- */
.lang-en{display:none}
html.en .lang-zh{display:none}
html.en .lang-en{display:inline}
html.en .lang-en.block{display:block}
html.en .lang-en.flex{display:flex}
.lang-en.block{display:none}
.lang-zh.block{display:block}

/* ---------- 顶部导航 ---------- */
.nav{
  position:sticky;top:0;z-index:50;
  background:rgba(255,255,255,.82);
  backdrop-filter:saturate(180%) blur(14px);
  border-bottom:1px solid var(--line);
}
.nav-inner{display:flex;align-items:center;justify-content:space-between;height:78px}
.brand{display:flex;align-items:center;gap:10px;font-weight:700;letter-spacing:.04em;font-size:18px}
.brand .mark{
  width:26px;height:26px;border-radius:7px;background:var(--ink);
  display:inline-flex;align-items:center;justify-content:center;color:#fff;font-size:14px;font-weight:800;
}
.brand.logo img{height:56px;width:auto;max-width:220px;display:block}
.footer .brand.logo img{height:28px}
.nav-links{display:flex;align-items:center;gap:30px}
.nav-links a{font-size:15px;color:var(--ink-soft);transition:color .2s}
.nav-links a:hover{color:var(--ink)}
.nav-right{display:flex;align-items:center;gap:14px}
.lang-btn{
  border:1px solid var(--line);border-radius:999px;padding:6px 14px;
  font-size:13px;color:var(--ink-soft);transition:.2s;
}
.lang-btn:hover{border-color:var(--ink);color:var(--ink)}
.btn{
  display:inline-flex;align-items:center;gap:8px;justify-content:center;
  padding:12px 22px;border-radius:999px;font-size:15px;font-weight:600;
  transition:.25s var(--ease);white-space:nowrap;
}
.btn-primary{background:var(--ink);color:#fff}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 10px 30px rgba(0,0,0,.18)}
.btn-ghost{border:1px solid var(--ink);color:var(--ink)}
.btn-ghost:hover{background:var(--ink);color:#fff}
.btn-sm{padding:9px 16px;font-size:14px}
.menu-toggle{display:none;width:42px;height:42px;border-radius:10px;border:1px solid var(--line);align-items:center;justify-content:center}
.menu-toggle span{display:block;width:18px;height:2px;background:var(--ink);position:relative}
.menu-toggle span::before,.menu-toggle span::after{content:"";position:absolute;left:0;width:18px;height:2px;background:var(--ink)}
.menu-toggle span::before{top:-6px}.menu-toggle span::after{top:6px}

/* ---------- 通用区块 ---------- */
section{padding:96px 0}
.sec-alt{background:var(--bg-alt)}
.eyebrow{
  font-size:13px;letter-spacing:.18em;text-transform:uppercase;
  color:var(--ink-faint);font-weight:600;margin-bottom:14px;
}
.h-sec{font-size:34px;line-height:1.25;font-weight:700;letter-spacing:-.01em}
.h-sec .thin{font-weight:300;color:var(--ink-soft)}
.sec-head{max-width:680px;margin-bottom:54px}
.sec-head p{margin-top:14px;color:var(--ink-soft);font-size:17px}

/* ---------- 首屏 Hero ---------- */
.hero{padding:120px 0 100px;background:
  radial-gradient(1200px 500px at 80% -10%, #f1f1f0 0%, transparent 60%),
  var(--bg);}
.hero h1{font-size:clamp(38px,5.4vw,62px);line-height:1.12;font-weight:700;letter-spacing:-.02em}
.hero h1 .accent{position:relative;white-space:nowrap}
.hero h1 .accent::after{content:"";position:absolute;left:0;right:0;bottom:6px;height:10px;background:#e9e9e7;z-index:-1}
.hero p.lead{margin:26px 0 36px;font-size:19px;color:var(--ink-soft);max-width:600px}
.hero-cta{display:flex;gap:14px;flex-wrap:wrap}
.hero-meta{margin-top:48px;display:flex;gap:34px;flex-wrap:wrap;color:var(--ink-faint);font-size:14px}
.hero-meta b{color:var(--ink);font-weight:700}

/* ---------- 数据指标 ---------- */
.stats{display:grid;grid-template-columns:repeat(4,1fr);gap:24px;border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.stat{padding:38px 8px}
.stat .num{font-size:42px;font-weight:700;letter-spacing:-.02em}
.stat .lab{margin-top:6px;color:var(--ink-soft);font-size:14px}

/* ---------- 卡片网格 ---------- */
.grid{display:grid;gap:22px}
.grid-3{grid-template-columns:repeat(3,1fr)}
.grid-2{grid-template-columns:repeat(2,1fr)}
.card{
  border:1px solid var(--line);border-radius:var(--radius);padding:30px;
  background:var(--bg);transition:.25s var(--ease);position:relative;overflow:hidden;
}
.card:hover{transform:translateY(-4px);border-color:var(--ink);box-shadow:0 18px 40px rgba(0,0,0,.07)}
.card .idx{font-size:13px;color:var(--ink-faint);font-weight:600;letter-spacing:.1em}
.card h3{font-size:20px;margin:14px 0 10px;font-weight:700}
.card p{color:var(--ink-soft);font-size:15px}
.card .tags{margin-top:18px;display:flex;flex-wrap:wrap;gap:8px}
.tag{font-size:12px;border:1px solid var(--line);border-radius:999px;padding:4px 11px;color:var(--ink-soft)}
.card .more{margin-top:18px;font-size:14px;font-weight:600;display:inline-flex;align-items:center;gap:6px}
.card .more::after{content:"→";transition:transform .2s}
.card:hover .more::after{transform:translateX(4px)}

/* ---------- 流程 ---------- */
.process{display:grid;grid-template-columns:repeat(5,1fr);gap:0;counter-reset:step}
.step{padding:28px 20px 28px 0;border-top:2px solid var(--ink);position:relative}
.step .n{counter-increment:step;font-size:13px;color:var(--ink-faint);font-weight:700;letter-spacing:.1em}
.step .n::before{content:"0" counter(step)}
.step h4{margin:12px 0 8px;font-size:17px;font-weight:700}
.step p{font-size:14px;color:var(--ink-soft)}

/* ---------- 案例 ---------- */
.case{
  border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;
  background:var(--bg);transition:.25s var(--ease);display:flex;flex-direction:column;
}
.case:hover{transform:translateY(-4px);box-shadow:0 18px 40px rgba(0,0,0,.07)}
.case .thumb{position:relative;aspect-ratio:16/10;background:linear-gradient(135deg,#ededeb,#f7f7f6);display:flex;align-items:flex-end;padding:18px;overflow:hidden}
.case .thumb .thumb-icon{position:absolute;inset:0;display:flex;align-items:center;justify-content:center;overflow:hidden}
.case .thumb .thumb-icon img{width:100%;height:100%;object-fit:cover}
.case .thumb .cat{position:relative;z-index:1;font-size:12px;background:var(--ink);color:#fff;padding:5px 12px;border-radius:999px;letter-spacing:.04em}
.case .body{padding:24px;flex:1;display:flex;flex-direction:column}
.case h3{font-size:19px;font-weight:700;margin-bottom:8px}
.case p{color:var(--ink-soft);font-size:14px;flex:1}
.case .foot{margin-top:18px;display:flex;justify-content:space-between;align-items:center;font-size:13px;color:var(--ink-faint)}
.filters{display:flex;flex-wrap:wrap;gap:10px;margin-bottom:34px}
.filter{border:1px solid var(--line);border-radius:999px;padding:8px 16px;font-size:14px;color:var(--ink-soft);transition:.2s}
.filter:hover{border-color:var(--ink);color:var(--ink)}
.filter.active{background:var(--ink);color:#fff;border-color:var(--ink)}

/* ---------- 评价 ---------- */
.quote{border:1px solid var(--line);border-radius:var(--radius);padding:34px;background:var(--bg-alt)}
.quote p{font-size:19px;line-height:1.6;font-weight:500}
.quote .who{margin-top:20px;font-size:14px;color:var(--ink-soft)}
.quote .who b{color:var(--ink)}

/* ---------- CTA 带 ---------- */
.cta-band{background:var(--bg-dark);color:#fff;border-radius:22px;padding:64px 48px;text-align:center}
.cta-band h2{font-size:34px;font-weight:700;letter-spacing:-.01em}
.cta-band p{margin:14px auto 30px;color:#bdbdbd;max-width:560px;font-size:17px}
.cta-band .btn-primary{background:#fff;color:var(--ink)}
.cta-band .btn-primary:hover{box-shadow:0 10px 30px rgba(255,255,255,.18)}

/* ---------- 关于页 ---------- */
.about-hero{padding:110px 0 70px}
.about-hero h1{font-size:clamp(34px,4.6vw,52px);font-weight:700;letter-spacing:-.02em;max-width:820px}
.about-hero p{margin-top:22px;font-size:18px;color:var(--ink-soft);max-width:680px}
.values{display:grid;grid-template-columns:repeat(3,1fr);gap:22px;margin-top:20px}
.value{border:1px solid var(--line);border-radius:var(--radius);padding:28px}
.value .ico{width:40px;height:40px;border-radius:10px;background:var(--bg-alt);display:flex;align-items:center;justify-content:center;font-size:20px;margin-bottom:16px}
.value h3{font-size:18px;font-weight:700;margin-bottom:8px}
.value p{color:var(--ink-soft);font-size:14px}
.timeline{margin-top:10px;border-left:2px solid var(--line)}
.timeline .row{padding:0 0 30px 28px;position:relative}
.timeline .row::before{content:"";position:absolute;left:-7px;top:4px;width:12px;height:12px;border-radius:50%;background:var(--ink)}
.timeline .yr{font-weight:700;font-size:15px}
.timeline p{color:var(--ink-soft);font-size:14px;margin-top:4px}

/* ---------- 联系页 ---------- */
.contact-grid{display:grid;grid-template-columns:1.1fr .9fr;gap:48px;align-items:start}
.form{display:grid;gap:18px}
.field label{display:block;font-size:14px;font-weight:600;margin-bottom:8px}
.field input,.field textarea,.field select{
  width:100%;border:1px solid var(--line);border-radius:10px;padding:13px 14px;
  font-size:15px;color:var(--ink);background:var(--bg);transition:.2s;font-family:inherit;
}
.field input:focus,.field textarea:focus,.field select:focus{outline:none;border-color:var(--ink)}
.field textarea{resize:vertical;min-height:120px}
.form-2{display:grid;grid-template-columns:1fr 1fr;gap:18px}
.info-card{border:1px solid var(--line);border-radius:var(--radius);padding:30px;background:var(--bg-alt)}
.info-card h3{font-size:17px;font-weight:700;margin-bottom:18px}
.info-row{display:flex;gap:12px;padding:12px 0;border-bottom:1px solid var(--line-soft);font-size:15px}
.info-row:last-child{border-bottom:none}
.info-row .k{color:var(--ink-faint);min-width:78px}
.form-note{font-size:13px;color:var(--ink-faint);margin-top:6px}
.ok-msg{display:none;background:var(--bg-alt);border:1px solid var(--line);border-radius:10px;padding:16px;font-size:14px;color:var(--ink-soft)}
.ok-msg.show{display:block}

/* ---------- 页脚 ---------- */
.footer{background:var(--bg-dark);color:#cfcfcf;padding:64px 0 30px;margin-top:40px}
.footer a{color:#cfcfcf;transition:.2s}
.footer a:hover{color:#fff}
.footer .top{display:grid;grid-template-columns:1.4fr 1fr 1fr 1fr;gap:30px;padding-bottom:40px;border-bottom:1px solid #2a2a2a}
.footer .brand{color:#fff}
.footer h5{color:#fff;font-size:14px;margin-bottom:16px;letter-spacing:.04em}
.footer ul{list-style:none;display:grid;gap:10px;font-size:14px}
.footer .desc{margin-top:16px;font-size:14px;color:#9a9a9a;max-width:300px}
.footer .bottom{display:flex;justify-content:space-between;flex-wrap:wrap;gap:12px;padding-top:24px;font-size:13px;color:#8a8a8a}

/* ---------- 浮动咨询按钮 ---------- */
.fab{
  position:fixed;right:24px;bottom:24px;z-index:60;
  background:var(--ink);color:#fff;border-radius:999px;padding:14px 22px;
  font-weight:600;font-size:15px;display:flex;align-items:center;gap:9px;
  box-shadow:0 12px 32px rgba(0,0,0,.22);transition:.25s var(--ease);
}
.fab:hover{transform:translateY(-3px);box-shadow:0 18px 40px rgba(0,0,0,.28)}
.fab .dot{width:8px;height:8px;border-radius:50%;background:#4ade80}

/* ---------- 响应式 ---------- */
@media(max-width:900px){
  .stats{grid-template-columns:repeat(2,1fr)}
  .grid-3,.grid-2{grid-template-columns:1fr}
  .process{grid-template-columns:1fr 1fr}
  .values{grid-template-columns:1fr}
  .contact-grid{grid-template-columns:1fr;gap:32px}
  .footer .top{grid-template-columns:1fr 1fr}
  .nav-links{
    position:fixed;inset:78px 0 auto 0;background:#fff;flex-direction:column;
    align-items:stretch;gap:0;padding:10px 24px 22px;border-bottom:1px solid var(--line);
    transform:translateY(-130%);transition:transform .3s var(--ease);box-shadow:0 20px 40px rgba(0,0,0,.06);
  }
  .nav-links.open{transform:translateY(0)}
  .nav-links a{padding:14px 0;border-bottom:1px solid var(--line-soft);font-size:16px}
  .menu-toggle{display:flex}
  .nav-links .btn{margin-top:12px}
  section{padding:70px 0}
  .cta-band{padding:48px 24px}
  .form-2{grid-template-columns:1fr}
}
@media(max-width:560px){
  .stats{grid-template-columns:1fr}
  .process{grid-template-columns:1fr}
  .footer .top{grid-template-columns:1fr}
  .h-sec{font-size:28px}
}