/* ===========================================================
   壹川文化 · 官网样式
   低饱和莫兰迪灰 + 浅银，微水泥颗粒肌理，克制的编辑式排版
   =========================================================== */

:root{
  --ink:#191817;
  --ink-soft:#3d3a36;
  --body:#57534d;
  --muted:#767169;
  --line:rgba(25,24,23,.13);
  --line-soft:rgba(25,24,23,.07);
  --paper:#f3f1ee;
  --paper-2:#eeece8;
  --mist:#e3e0da;
  --silver:#c8c4bd;
  --accent:#8c1b1f;
  --wrap:1240px;
  --ease:cubic-bezier(.22,.68,.16,1);
  --serif:"Source Han Serif CN","Songti SC","Noto Serif CJK SC","SimSun",serif;
  --sans:"PingFang SC","Hiragino Sans GB","Source Han Sans CN","Microsoft YaHei",-apple-system,sans-serif;
}

*{box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{
  margin:0;background:var(--paper);color:var(--body);
  font-family:var(--sans);font-size:16px;line-height:1.9;letter-spacing:.01em;
  -webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility;
  overflow-x:hidden;
}

/* 微水泥颗粒：极细噪点 + 柔和暗角 */
.grain{
  position:fixed;inset:0;z-index:60;pointer-events:none;
  opacity:.055;mix-blend-mode:multiply;
  background-image:url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='180' height='180'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='.82' numOctaves='3' stitchTiles='stitch'/><feColorMatrix type='saturate' values='0'/></filter><rect width='180' height='180' filter='url(%23n)' opacity='.55'/></svg>");
}
.grain::after{
  content:"";position:absolute;inset:0;
  background:radial-gradient(120% 90% at 50% 0%,rgba(255,255,255,.5),transparent 55%),
             radial-gradient(90% 60% at 50% 100%,rgba(25,24,23,.05),transparent 60%);
}

img{display:block;max-width:100%;height:auto}
a{color:inherit;text-decoration:none}
h1,h2,h3,h4{margin:0;font-family:var(--serif);font-weight:400;color:var(--ink);letter-spacing:.02em}
p{margin:0}
ul,ol,dl{margin:0;padding:0;list-style:none}

.wrap{width:min(100% - 8vw,var(--wrap));margin-inline:auto}

/* ---------- 通用标题排布 ---------- */
.eyebrow{
  display:flex;align-items:center;gap:.8em;
  font-family:var(--sans);font-size:11.5px;letter-spacing:.32em;text-transform:uppercase;
  color:var(--muted);margin:0 0 22px;
}
.eyebrow::before{content:"";width:26px;height:1px;background:var(--silver);flex:none}

h2{font-size:clamp(26px,3.4vw,42px);line-height:1.32}
.section-lead{max-width:44em;margin-top:18px;color:var(--body);font-size:15.5px}

.section{padding:clamp(72px,9vw,140px) 0;position:relative}
.section + .section{border-top:1px solid var(--line-soft)}
.section-head{max-width:760px;margin-bottom:clamp(34px,5vw,62px)}

/* ---------- 页头 ---------- */
.site-head{
  position:fixed;inset:0 0 auto;z-index:50;
  transition:background .5s var(--ease),border-color .5s var(--ease),backdrop-filter .5s;
  border-bottom:1px solid transparent;
}
.site-head.is-solid{background:rgba(243,241,238,.86);backdrop-filter:blur(14px) saturate(1.1);border-bottom-color:var(--line-soft)}
.head-inner{display:flex;align-items:center;gap:clamp(16px,3vw,44px);height:76px}
.brand{display:flex;align-items:center;gap:12px;flex:none}
.brand-mark{height:38px;width:auto}
.brand-text{display:flex;flex-direction:column;line-height:1.1}
.brand-text strong{font-family:var(--serif);font-weight:400;font-size:17px;color:var(--ink);letter-spacing:.14em}
.brand-text em{font-style:normal;font-size:8.5px;letter-spacing:.36em;color:var(--muted);margin-top:5px}
.nav{display:flex;gap:clamp(18px,2.4vw,34px);margin-left:auto}
.nav a{
  position:relative;font-size:13.5px;letter-spacing:.12em;color:var(--ink);padding:6px 0;
}
.nav a::after{
  content:"";position:absolute;left:0;bottom:0;height:1px;width:0;background:var(--ink);
  transition:width .45s var(--ease);
}
.nav a:hover::after{width:100%}
.head-cta{
  flex:none;font-size:13px;font-weight:500;letter-spacing:.14em;color:#f6f4f1;
  background:var(--ink);border:1px solid var(--ink);border-radius:999px;padding:10px 22px;
  transition:background .4s var(--ease),color .4s,border-color .4s,transform .4s var(--ease);
}
.head-cta:hover{background:#000;border-color:#000;transform:translateY(-1px)}
.nav-toggle{display:none}

/* ---------- 首屏 ---------- */
.hero{position:relative;min-height:100svh;display:flex;align-items:flex-end;overflow:hidden}
.hero-media{position:absolute;inset:0;z-index:0}
.hero-media img{width:100%;height:100%;object-fit:cover;object-position:72% 55%}
.hero-media::after{
  content:"";position:absolute;inset:0;
  background:linear-gradient(100deg,rgba(243,241,238,.96) 0%,rgba(243,241,238,.88) 40%,rgba(243,241,238,.24) 66%,rgba(243,241,238,0) 86%),
             linear-gradient(0deg,rgba(243,241,238,.85) 0%,rgba(243,241,238,0) 42%);
}
.hero-inner{position:relative;z-index:1;padding:150px 0 clamp(46px,6vw,76px)}
.hero h1{
  font-size:clamp(38px,6.4vw,86px);line-height:1.14;letter-spacing:.02em;
  color:var(--ink);margin:0 0 26px;text-wrap:balance;
}
.hero .lead{max-width:30em;font-size:clamp(14.5px,1.1vw,16.5px);color:var(--ink-soft);line-height:2.05;text-wrap:pretty}
.hero-actions{display:flex;flex-wrap:wrap;gap:14px;margin:34px 0 0}

.btn{
  display:inline-flex;align-items:center;gap:.6em;
  font-size:13.5px;letter-spacing:.14em;padding:14px 30px;border-radius:999px;
  border:1px solid transparent;transition:transform .5s var(--ease),background .4s,color .4s,border-color .4s;
}
.btn:hover{transform:translateY(-2px)}
.btn-solid{background:var(--ink);color:#f6f4f1}
.btn-solid:hover{background:#000}
.btn-ghost{border-color:rgba(25,24,23,.28);color:var(--ink)}
.btn-ghost:hover{background:rgba(25,24,23,.05);border-color:var(--ink)}

.stats{
  display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:clamp(14px,3vw,40px);
  margin:clamp(40px,6vw,68px) 0 0;padding-top:26px;border-top:1px solid var(--line);
  max-width:760px;
}
.stats dt{font-family:var(--serif);font-size:clamp(24px,2.6vw,34px);color:var(--ink);line-height:1}
.stats dt span{font-size:.44em;margin-left:.18em;color:var(--muted);letter-spacing:.1em}
.stats dd{margin:10px 0 0;font-size:12px;letter-spacing:.22em;color:#57534d}

.scroll-cue{
  position:absolute;right:calc(4vw);bottom:34px;z-index:2;
  display:flex;align-items:center;gap:10px;
  font-size:9.5px;letter-spacing:.4em;color:#7d7870;
  writing-mode:vertical-rl;
}
.scroll-cue span{display:block;width:1px;height:56px;background:linear-gradient(var(--silver),transparent)}

/* ---------- 关于 ---------- */
.split{display:grid;grid-template-columns:1.05fr .82fr;gap:clamp(30px,6vw,86px);align-items:center}
.split-text h2{margin-bottom:26px}
.prose p + p{margin-top:1.1em}
.prose{max-width:36em}
.split-media{margin:0}
.split-media img{
  width:100%;aspect-ratio:3/4;object-fit:cover;
  filter:saturate(.96);
}
.split-media figcaption{
  margin-top:10px;font-size:11.5px;letter-spacing:.16em;color:var(--muted);
  padding-left:14px;border-left:1px solid var(--silver);line-height:1.8;
}

/* ---------- 业务卡片 ---------- */
.cards{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:clamp(14px,1.6vw,22px)}
.cards-3{grid-template-columns:repeat(3,minmax(0,1fr))}
.card{
  position:relative;padding:clamp(26px,3vw,40px);
  background:linear-gradient(160deg,rgba(255,255,255,.62),rgba(255,255,255,.16));
  border:1px solid var(--line-soft);
  transition:border-color .5s var(--ease),background .5s var(--ease),transform .6s var(--ease);
}
.card:hover{border-color:rgba(25,24,23,.22);transform:translateY(-3px)}
.card .num{
  display:block;font-family:var(--serif);font-size:12px;letter-spacing:.3em;color:var(--accent);
  margin-bottom:clamp(20px,2.6vw,32px);
}
.card h3{font-size:clamp(20px,2vw,25px);margin-bottom:14px}
.card p{font-size:14.5px;line-height:1.95;color:var(--body);max-width:32em}
.tags{display:flex;flex-wrap:wrap;gap:8px;margin-top:24px}
.tags li{
  font-size:11.5px;letter-spacing:.1em;color:#655f57;
  border:1px solid rgba(25,24,23,.16);border-radius:999px;padding:5px 12px;
}
.footnote{
  margin-top:clamp(24px,3vw,38px);font-size:12.5px;letter-spacing:.06em;color:var(--muted);
  padding-left:16px;border-left:1px solid var(--silver);
}

/* ---------- 案例 ---------- */
.case-split{display:grid;grid-template-columns:1.32fr .68fr;gap:clamp(28px,4.4vw,64px);align-items:start}
.case-list li{padding:22px 0;border-top:1px solid var(--line-soft)}
.case-list li:first-child{border-top:0;padding-top:0}
.case-list h4{
  font-family:var(--sans);font-size:12.5px;font-weight:600;letter-spacing:.2em;color:var(--ink);
  margin-bottom:10px;
}
.case-list p{font-size:14px;line-height:2.05;color:#4f4b45;text-indent:0}
.case-media{margin:0;position:sticky;top:104px}
.case-media img{width:100%;aspect-ratio:4/5;object-fit:cover;filter:saturate(.94) contrast(1.02)}
.case-media figcaption{
  margin-top:12px;font-size:11px;letter-spacing:.14em;color:#7c766e;
  padding-left:12px;border-left:1px solid var(--silver);line-height:1.8;
}

/* ---------- 流程 ---------- */
.steps{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:clamp(18px,2.4vw,34px) clamp(20px,3vw,44px)}
.steps li{padding-top:22px;border-top:1px solid var(--line);position:relative}
.steps span{
  display:block;font-family:var(--serif);font-size:11px;letter-spacing:.3em;color:var(--accent);margin-bottom:14px;
}
.steps h3{font-size:19px;margin-bottom:8px}
.steps p{font-size:13.5px;line-height:1.95;color:var(--body)}

/* ---------- 联系 ---------- */
.contact{
  background:linear-gradient(180deg,var(--paper) 0%,var(--paper-2) 100%);
}
.contact-inner{max-width:900px}
.contact h2{font-size:clamp(30px,4.6vw,54px);line-height:1.28;margin-bottom:22px}
.contact .lead{max-width:36em;color:var(--ink-soft)}
.contact-actions{display:flex;align-items:center;flex-wrap:wrap;gap:18px;margin:36px 0 0}
.contact-alt{font-size:12px;letter-spacing:.16em;color:var(--muted)}
.contact-meta{
  display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px 26px;
  margin-top:clamp(40px,5vw,64px);padding-top:26px;border-top:1px solid var(--line);
  font-size:13px;color:var(--body);
}
.contact-meta span{
  display:block;font-size:11px;letter-spacing:.22em;color:#6b665f;margin-bottom:8px;
}
.contact-meta a{border-bottom:1px solid var(--line);padding-bottom:2px;transition:border-color .3s}
.contact-meta a:hover{border-color:var(--ink)}

/* ---------- 页脚 ---------- */
.site-foot{padding:clamp(46px,6vw,70px) 0 clamp(34px,4vw,48px);background:var(--paper-2);border-top:1px solid var(--line-soft)}
.foot-inner{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:30px}
.foot-brand img{height:60px;width:auto;opacity:.9}
.foot-meta{text-align:right}
.foot-line{font-size:12px;letter-spacing:.22em;color:var(--ink-soft);margin-bottom:10px}
.foot-small{font-size:11.5px;letter-spacing:.1em;color:var(--muted);line-height:2}
.foot-small a{border-bottom:1px solid var(--line)}

/* ---------- 滚动入场 ---------- */
.reveal{opacity:0;transform:translateY(16px);transition:opacity 1s var(--ease) var(--d,0ms),transform 1s var(--ease) var(--d,0ms)}
.reveal.in{opacity:1;transform:none}

:focus-visible{outline:1px solid var(--ink);outline-offset:4px}

/* ---------- 响应式 ---------- */
@media (max-width:1080px){
  .case-split{grid-template-columns:1fr}
  .case-media{position:static;order:-1}
  .case-media img{aspect-ratio:16/10}
  .steps{grid-template-columns:repeat(2,minmax(0,1fr))}
  .cards-3{grid-template-columns:1fr}
}

@media (max-width:860px){
  .nav,.head-cta{display:none}
  .nav-toggle{
    display:flex;flex-direction:column;justify-content:center;gap:5px;margin-left:auto;
    width:44px;height:44px;padding:0 10px;background:none;border:1px solid var(--line);border-radius:999px;
  }
  .nav-toggle span{display:block;height:1px;background:var(--ink);transition:transform .4s var(--ease),opacity .3s}
  body.nav-open .nav-toggle span:first-child{transform:translateY(3px) rotate(45deg)}
  body.nav-open .nav-toggle span:last-child{transform:translateY(-3px) rotate(-45deg)}
  body.nav-open .nav{
    display:flex;flex-direction:column;gap:0;
    position:fixed;inset:76px 0 auto;background:rgba(243,241,238,.97);
    backdrop-filter:blur(16px);padding:8px 6vw 26px;border-bottom:1px solid var(--line);
  }
  body.nav-open .nav a{padding:16px 0;border-bottom:1px solid var(--line-soft);font-size:15px;letter-spacing:.16em}
  .split{grid-template-columns:1fr}
  .split-media img{aspect-ratio:4/3}
  .cards{grid-template-columns:1fr}
  .hero{min-height:auto}
  .hero-inner{padding:132px 0 54px}
  .hero-media img{object-position:62% 50%}
  .hero-media::after{background:linear-gradient(0deg,rgba(243,241,238,.97) 6%,rgba(243,241,238,.86) 46%,rgba(243,241,238,.42) 100%)}
  .stats{grid-template-columns:repeat(2,minmax(0,1fr));gap:22px}
  .scroll-cue{display:none}
  .contact-meta{grid-template-columns:1fr}
  .contact-actions{gap:14px}
  .contact-alt{flex-basis:100%;font-size:11.5px;letter-spacing:.12em}
  .foot-small{font-size:11px;letter-spacing:.06em;word-break:break-word}
  .foot-inner{flex-direction:column;align-items:flex-start}
  .foot-meta{text-align:left}
  .foot-brand img{height:54px}
}

@media (max-width:520px){
  .steps{grid-template-columns:1fr}
  .hero h1{font-size:clamp(32px,9vw,44px)}
}