/* ==========================================================================
   尧图网站建设 rkmt.cn · 主样式表 style.css
   设计语言：锯齿线条叠加分割 + 单人沙发风（浅灰 / 米白 / 原木色）
   ========================================================================== */

/* ---------- 设计变量 ---------- */
:root{
  /* 原木色系 */
  --wood:#B89968;
  --wood-light:#D4BC95;
  --wood-deep:#9A7D4F;
  --wood-soft:#E5D5B8;
  /* 浅灰色系 */
  --gray:#8B8680;
  --gray-mid:#A09A92;
  --gray-light:#D8D4CE;
  --gray-bg:#EDE9E3;
  /* 米白 / 纸张 */
  --cream:#F7F4EF;
  --paper:#FDFBF7;
  --cream-deep:#EFE9DF;
  /* 墨色文字 */
  --ink:#2C2924;
  --ink-soft:#5C5750;
  --ink-mute:#8A857C;
  /* 功能色 */
  --line:rgba(155,125,79,.18);
  --line-strong:rgba(155,125,79,.35);
  --shadow:0 24px 60px -28px rgba(60,50,30,.28);
  --shadow-soft:0 14px 36px -20px rgba(60,50,30,.22);
  --radius:14px;
  --radius-sm:8px;
  --maxw:1240px;
  --nav-h:74px;
  --ease:cubic-bezier(.22,.61,.36,1);
  --serif:Georgia,"Songti SC","STSong","Source Han Serif SC",serif;
  --sans:"Helvetica Neue",-apple-system,"PingFang SC","Microsoft YaHei",sans-serif;
}

/* ---------- 基础重置 ---------- */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{
  font-family:var(--sans);
  font-size:15.5px;
  line-height:1.75;
  color:var(--ink);
  background:var(--cream);
  overflow-x:hidden;
  -webkit-font-smoothing:antialiased;
}
img{max-width:100%;height:auto;display:block}
a{color:inherit;text-decoration:none;transition:color .25s var(--ease)}
ul,ol{list-style:none}
button{font-family:inherit;cursor:pointer;border:none;background:none}
input,textarea,select{font-family:inherit;font-size:inherit;color:inherit}

/* ---------- 排版 ---------- */
h1,h2,h3,h4,h5{font-family:var(--serif);font-weight:700;color:var(--ink);line-height:1.28;letter-spacing:.3px}
h1{font-size:clamp(2rem,4.6vw,3.4rem)}
h2{font-size:clamp(1.6rem,3.2vw,2.4rem)}
h3{font-size:clamp(1.25rem,2vw,1.6rem)}
h4{font-size:1.1rem}
p{color:var(--ink-soft)}
.accent{color:var(--wood-deep);font-style:italic;font-family:var(--serif)}

/* ---------- 容器 ---------- */
.container{width:100%;max-width:var(--maxw);margin:0 auto;padding:0 28px}
.section{position:relative;padding:96px 0}
.section.tight{padding:60px 0}
.section.narrow{padding:80px 0}
.bg-cream{background:var(--cream)}
.bg-paper{background:var(--paper)}
.bg-wood{background:linear-gradient(135deg,var(--wood-soft),var(--wood-light));color:var(--ink)}
.bg-gray{background:var(--gray-bg)}
.bg-ink{background:#2C2924;color:var(--cream)}

/* ---------- 锯齿线条叠加分割（核心视觉特征） ---------- */
/* 顶部锯齿分割线：三层叠加 */
.zig-top{position:relative}
.zig-top::before,.zig-top::after{
  content:"";position:absolute;left:0;right:0;top:-1px;height:18px;
  background-image:linear-gradient(135deg,transparent 49.5%,var(--cream) 50%),
                   linear-gradient(-135deg,transparent 49.5%,var(--cream) 50%);
  background-size:36px 18px;background-repeat:repeat-x;background-position:0 0,18px 0;
}
.zig-top::after{
  height:10px;top:6px;opacity:.5;
  background-image:linear-gradient(135deg,transparent 49.5%,var(--wood-light) 50%),
                   linear-gradient(-135deg,transparent 49.5%,var(--wood-light) 50%);
  background-size:24px 10px;background-position:0 0,12px 0;
}
/* 反向锯齿（向下） */
.zig-bottom{position:relative}
.zig-bottom::before,.zig-bottom::after{
  content:"";position:absolute;left:0;right:0;bottom:-1px;height:18px;
  background-image:linear-gradient(45deg,var(--cream) 49.5%,transparent 50%),
                   linear-gradient(-45deg,var(--cream) 49.5%,transparent 50%);
  background-size:36px 18px;background-repeat:repeat-x;background-position:0 0,18px 0;
}
.zig-bottom::after{
  height:10px;bottom:6px;opacity:.5;
  background-image:linear-gradient(45deg,var(--wood-light) 49.5%,transparent 50%),
                   linear-gradient(-45deg,var(--wood-light) 49.5%,transparent 50%);
  background-size:24px 10px;background-position:0 0,12px 0;
}
/* 暗底锯齿 */
.bg-ink.zig-top::before,.bg-ink.zig-bottom::before{--cream:#2C2924}
.bg-ink.zig-top::after,.bg-ink.zig-bottom::after{--wood-light:rgba(184,153,104,.25)}
/* 木色底锯齿 */
.bg-wood.zig-top::before,.bg-wood.zig-bottom::before{--cream:var(--wood-soft)}
.bg-wood.zig-top::after,.bg-wood.zig-bottom::after{--wood-light:var(--wood-deep)}

/* 装饰性多层锯齿线条（独立元素） */
.zig-deco{
  display:block;width:100%;height:14px;
  background-image:
    linear-gradient(135deg,transparent 49.5%,var(--wood-deep) 50%,var(--wood-deep) 51%,transparent 51.5%),
    linear-gradient(-135deg,transparent 49.5%,var(--gray-mid) 50%,var(--gray-mid) 51%,transparent 51.5%),
    linear-gradient(135deg,transparent 49.5%,var(--wood-light) 50%,var(--wood-light) 51%,transparent 51.5%);
  background-size:48px 14px,48px 14px,32px 10px;
  background-repeat:repeat-x;
  background-position:0 0,24px 4px,0 8px;
  opacity:.6;
}
.zig-deco.thin{height:8px;background-size:32px 8px,32px 8px,24px 6px}

/* ---------- 顶部固定导航栏 ---------- */
.topbar{
  position:fixed;top:0;left:0;right:0;z-index:1000;
  height:var(--nav-h);
  display:flex;align-items:center;
  transition:background .4s var(--ease),box-shadow .4s var(--ease),backdrop-filter .4s;
  background:transparent;
}
.topbar.scrolled{
  background:rgba(253,251,247,.92);
  backdrop-filter:blur(14px);
  -webkit-backdrop-filter:blur(14px);
  box-shadow:0 6px 30px -16px rgba(60,50,30,.25);
  border-bottom:1px solid var(--line);
}
.topbar .nav-wrap{
  width:100%;max-width:var(--maxw);margin:0 auto;padding:0 24px;
  display:flex;align-items:center;justify-content:space-between;gap:18px;
}
.topbar .brand{display:flex;align-items:center;gap:10px;flex-shrink:0}
.topbar .brand img{height:38px;width:auto}
.topbar .brand .brand-mark{
  width:38px;height:38px;display:flex;align-items:center;justify-content:center;
}
.nav-menu{display:flex;align-items:center;gap:1px;flex:1;justify-content:center}
.nav-menu > li{position:relative;flex-shrink:0}
.nav-menu > li > a{
  display:flex;align-items:center;gap:4px;
  padding:9px 11px;font-size:14px;font-weight:500;color:var(--ink);white-space:nowrap;
  border-radius:var(--radius-sm);transition:all .25s var(--ease);
}
.nav-menu > li > a .en{display:none}
.topbar:not(.scrolled) .nav-menu > li > a{color:var(--paper)}
.nav-menu > li > a:hover{color:var(--wood-deep)}
.topbar:not(.scrolled) .nav-menu > li > a:hover{color:var(--wood-light)}
.nav-menu > li > a.active{color:var(--wood-deep)}
.topbar:not(.scrolled) .nav-menu > li > a.active{color:var(--wood-light)}
/* 二级菜单 */
.has-sub > a::after{content:"";display:inline-block;width:0;height:0;border:4px solid transparent;border-top-color:currentColor;margin-left:3px;opacity:.5}
.sub-menu{
  position:absolute;top:calc(100% + 8px);left:50%;transform:translateX(-50%) translateY(8px);
  min-width:170px;background:var(--paper);border:1px solid var(--line);
  border-radius:var(--radius);box-shadow:var(--shadow-soft);padding:8px;
  opacity:0;visibility:hidden;transition:all .28s var(--ease);
}
.has-sub:hover .sub-menu{opacity:1;visibility:visible;transform:translateX(-50%) translateY(0)}
.sub-menu a{display:block;padding:9px 14px;font-size:13px;color:var(--ink-soft);border-radius:var(--radius-sm);white-space:nowrap}
.sub-menu a:hover{background:var(--cream-deep);color:var(--wood-deep)}

.nav-cta{
  display:inline-flex;align-items:center;gap:6px;
  padding:9px 18px;font-size:13px;font-weight:600;color:#fff;white-space:nowrap;
  background:var(--wood-deep);border-radius:30px;transition:all .25s var(--ease);flex-shrink:0;
}
.nav-cta:hover{background:var(--wood);transform:translateY(-1px)}

/* 汉堡按钮 */
.hamburger{
  display:none;width:42px;height:42px;position:relative;
}
.hamburger span{
  position:absolute;left:10px;right:10px;height:2px;background:var(--ink);
  border-radius:2px;transition:all .3s var(--ease);
}
.topbar:not(.scrolled) .hamburger span{background:var(--paper)}
.hamburger span:nth-child(1){top:14px}
.hamburger span:nth-child(2){top:20px}
.hamburger span:nth-child(3){top:26px}
.hamburger.open span:nth-child(1){top:20px;transform:rotate(45deg)}
.hamburger.open span:nth-child(2){opacity:0}
.hamburger.open span:nth-child(3){top:20px;transform:rotate(-45deg)}

/* 移动端抽屉 */
.mobile-drawer{
  position:fixed;top:0;right:0;z-index:999;
  width:min(86vw,360px);height:100vh;background:var(--paper);
  transform:translateX(100%);transition:transform .4s var(--ease);
  display:flex;flex-direction:column;padding:calc(var(--nav-h) + 16px) 24px 24px;
  overflow-y:auto;box-shadow:-20px 0 60px -30px rgba(0,0,0,.3);
}
.mobile-drawer.open{transform:translateX(0)}
.mobile-drawer .m-nav{display:flex;flex-direction:column;gap:2px}
.mobile-drawer .m-nav > a,.mobile-drawer .m-nav .m-has-sub > .m-title{
  display:flex;justify-content:space-between;align-items:center;
  padding:14px 12px;font-size:15px;color:var(--ink);
  border-bottom:1px solid var(--line);cursor:pointer;
}
.mobile-drawer .m-nav .m-sub{display:none;flex-direction:column;padding-left:16px}
.mobile-drawer .m-nav .m-has-sub.open .m-sub{display:flex}
.mobile-drawer .m-nav .m-sub a{padding:10px 12px;font-size:13.5px;color:var(--ink-soft)}
.mobile-drawer .m-cta{margin-top:20px;text-align:center}
.mobile-drawer .m-contact{margin-top:auto;padding-top:20px;border-top:1px solid var(--line);font-size:13px;color:var(--ink-mute)}
.drawer-overlay{position:fixed;inset:0;z-index:998;background:rgba(44,41,36,.4);opacity:0;visibility:hidden;transition:all .3s}
.drawer-overlay.open{opacity:1;visibility:visible}

/* ---------- 区块标题 ---------- */
.sec-head{margin-bottom:48px;position:relative}
.sec-head.center{text-align:center;margin-left:auto;margin-right:auto;max-width:680px}
.sec-head .eyebrow{
  display:inline-flex;align-items:center;gap:8px;
  font-size:12px;font-weight:600;letter-spacing:3px;text-transform:uppercase;
  color:var(--wood-deep);margin-bottom:14px;
}
.sec-head .eyebrow::before{content:"";width:24px;height:2px;background:var(--wood)}
.sec-head h2{margin-bottom:14px}
.sec-head p{font-size:15px;color:var(--ink-mute);max-width:60ch}
.sec-head.center p{margin-left:auto;margin-right:auto}

/* ---------- 滚动渐入动画 ---------- */
.reveal{opacity:0;transform:translateY(28px);transition:opacity .8s var(--ease),transform .8s var(--ease)}
.reveal.in{opacity:1;transform:none}
.reveal.d1{transition-delay:.1s}
.reveal.d2{transition-delay:.2s}
.reveal.d3{transition-delay:.3s}
.reveal.d4{transition-delay:.4s}

/* ---------- 返回顶部 ---------- */
.back-top{
  position:fixed;right:24px;bottom:24px;z-index:900;
  width:46px;height:46px;border-radius:50%;
  background:var(--wood-deep);color:#fff;display:flex;align-items:center;justify-content:center;
  opacity:0;visibility:hidden;transform:translateY(12px);transition:all .3s var(--ease);
  box-shadow:var(--shadow-soft);
}
.back-top.show{opacity:1;visibility:visible;transform:none}
.back-top:hover{background:var(--wood)}

/* ---------- 页脚 ---------- */
.site-foot{background:#26231F;color:var(--cream);padding:72px 0 0;position:relative}
.site-foot .zig-deco{position:absolute;top:0;left:0;right:0;opacity:.35}
.foot-grid{display:grid;grid-template-columns:1.6fr 1fr 1fr 1.3fr;gap:40px;padding-bottom:48px}
.foot-col h4{color:#fff;margin-bottom:18px;font-size:15px;font-family:var(--sans);letter-spacing:1px}
.foot-col p{color:rgba(247,244,239,.6);font-size:13.5px;line-height:1.8}
.foot-brand{display:flex;align-items:center;gap:10px;margin-bottom:14px}
.foot-brand img{height:36px;width:auto;filter:brightness(0) invert(1)}
.foot-brand strong{color:#fff;font-size:17px}
.foot-col ul li{margin-bottom:10px}
.foot-col ul li a{font-size:13.5px;color:rgba(247,244,239,.65);transition:color .2s}
.foot-col ul li a:hover{color:var(--wood-light)}
.foot-contact li{display:flex;align-items:flex-start;gap:9px;color:rgba(247,244,239,.7);font-size:13.5px;margin-bottom:12px;line-height:1.6}
.foot-contact svg{flex-shrink:0;margin-top:3px}
.foot-bottom{
  border-top:1px solid rgba(247,244,239,.12);padding:22px 0;
  display:flex;align-items:center;justify-content:space-between;gap:16px;flex-wrap:wrap;
}
.foot-bottom p{font-size:12.5px;color:rgba(247,244,239,.5)}
.foot-bottom .icp{color:var(--wood-light)}
.foot-links{display:flex;gap:18px}
.foot-links a{font-size:12.5px;color:rgba(247,244,239,.55)}
.foot-links a:hover{color:var(--wood-light)}

/* ---------- 面包屑 ---------- */
.breadcrumb{display:flex;align-items:center;gap:8px;font-size:13px;color:var(--ink-mute);margin-bottom:32px;flex-wrap:wrap}
.breadcrumb a:hover{color:var(--wood-deep)}
.breadcrumb span{opacity:.5}
.breadcrumb .current{color:var(--ink)}

/* ---------- 页面顶部 hero（内页） ---------- */
.page-hero{
  position:relative;padding:calc(var(--nav-h) + 64px) 0 56px;
  background:linear-gradient(135deg,var(--cream-deep),var(--cream));
  overflow:hidden;
}
.page-hero::before{
  content:"";position:absolute;top:30%;right:-8%;width:380px;height:380px;
  background:radial-gradient(circle,rgba(184,153,104,.12),transparent 70%);border-radius:50%;
}
.page-hero .eyebrow{
  display:inline-block;font-size:12px;font-weight:600;letter-spacing:3px;text-transform:uppercase;
  color:var(--wood-deep);margin-bottom:16px;
}
.page-hero h1{margin-bottom:14px}
.page-hero p{font-size:16px;color:var(--ink-soft);max-width:60ch}

/* ---------- 响应式 ---------- */
@media (max-width:1150px){
  :root{--nav-h:64px}
  .nav-menu,.nav-cta{display:none}
  .hamburger{display:block}
}
@media (max-width:1080px){
  .foot-grid{grid-template-columns:1fr 1fr;gap:32px}
}
@media (max-width:880px){
  :root{--nav-h:62px}
  .section{padding:72px 0}
  .foot-grid{grid-template-columns:1fr;gap:28px}
  .foot-bottom{flex-direction:column;align-items:flex-start}
}
@media (max-width:560px){
  .container{padding:0 20px}
  body{font-size:14.5px}
  .section{padding:60px 0}
  .zig-top::before,.zig-bottom::before{height:12px;background-size:24px 12px}
  .zig-top::after,.zig-bottom::after{height:7px;background-size:16px 7px}
}