/* ============================================================
   龙铭特种作业考证服务中心 · 全站共享基础样式 base.css
   风格：极简潮鞋风（哑光黑 + 纯白 + 浅灰）· 对角斜线渐变体系
   说明：本文件为全站公共层（导航/页脚/按钮/渐入动画/响应式），
         每个页面各自的独特对角布局写在 css/pages/<页面名>.css 中。
   ============================================================ */

/* ---------- 设计令牌 ---------- */
:root{
  --ink:#0b0b0c;          /* 哑光黑（主底） */
  --ink-2:#131315;        /* 次级黑 */
  --ink-3:#1c1c1f;        /* 面板黑 */
  --paper:#f4f4f0;        /* 纯白偏暖（浅底） */
  --paper-2:#eaeae5;      /* 浅灰底 */
  --line:rgba(255,255,255,.09);   /* 深底分隔线 */
  --line-dark:rgba(11,11,12,.12); /* 浅底分隔线 */
  --txt-on-dark:#f2f2ee;
  --txt-on-light:#17171a;
  --muted-dark:#9c9c96;
  --muted-light:#5c5c58;
  --header-h:72px;
  --font:"PingFang SC","Microsoft YaHei","Segoe UI",system-ui,-apple-system,sans-serif;
  --ease:cubic-bezier(.22,.61,.36,1);
}

/* ---------- 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(--font);
  background:var(--ink);
  color:var(--txt-on-dark);
  line-height:1.75;
  font-size:16px;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
img{max-width:100%;display:block}
a{color:inherit;text-decoration:none}
ul,ol{list-style:none}
button{font-family:inherit;cursor:pointer;border:0;background:none;color:inherit}
input,select,textarea{font-family:inherit;font-size:inherit;color:inherit}
::selection{background:#fff;color:#000}

/* ---------- 布局容器 ---------- */
.container{width:min(1200px,92%);margin-inline:auto}
.section{position:relative;padding:96px 0}
.section-tight{padding:64px 0}

/* ---------- 区块标题体系 ---------- */
.sec-head{display:flex;align-items:flex-end;justify-content:space-between;gap:24px;margin-bottom:52px}
.sec-head .t-en{
  display:block;font-size:12px;letter-spacing:.34em;text-transform:uppercase;
  color:var(--muted-dark);margin-bottom:10px;font-weight:600;
}
.sec-title{font-size:clamp(26px,3.4vw,40px);line-height:1.25;font-weight:800;letter-spacing:.01em}
.sec-title b,.sec-title .hl{font-weight:900}
.sec-sub{max-width:640px;color:var(--muted-dark);font-size:15px;margin-top:12px}
.sec-more{
  flex:none;font-size:14px;color:var(--muted-dark);display:inline-flex;align-items:center;gap:8px;
  padding-bottom:4px;border-bottom:1px solid var(--line);transition:.35s var(--ease);
}
.sec-more:hover{color:#fff;border-color:#fff;gap:14px}
.light-sec .sec-more:hover{color:#000;border-color:#000}

/* ---------- 按钮 ---------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:10px;
  padding:14px 30px;font-size:15px;font-weight:700;letter-spacing:.04em;
  border-radius:4px;transition:all .35s var(--ease);position:relative;overflow:hidden;
}
.btn-lg{padding:17px 38px;font-size:16px}
.btn-solid{background:#fff;color:#0b0b0c}
.btn-solid:hover{background:#e7e7e2;transform:translateY(-2px);box-shadow:0 14px 34px rgba(255,255,255,.14)}
.btn-line{border:1px solid rgba(255,255,255,.42);color:#fff}
.btn-line:hover{border-color:#fff;background:rgba(255,255,255,.08);transform:translateY(-2px)}
.btn-white{background:#0b0b0c;color:#fff}
.btn-white:hover{background:#2a2a2e;transform:translateY(-2px)}
.btn-line-dark{border:1px solid rgba(11,11,12,.35);color:#17171a}
.btn-line-dark:hover{border-color:#000;background:rgba(11,11,12,.05)}

/* ---------- 小标签 / 角标 ---------- */
.tag{
  display:inline-flex;align-items:center;gap:8px;font-size:12px;letter-spacing:.18em;
  color:var(--muted-dark);border:1px solid var(--line);border-radius:999px;padding:7px 16px;
}
.tag i{width:6px;height:6px;border-radius:50%;background:#fff;box-shadow:0 0 10px #fff}
.light-sec .tag{color:var(--muted-light);border-color:var(--line-dark)}
.light-sec .tag i{background:#000}

/* ---------- 滚动渐入动画 ---------- */
.rv{opacity:0;transform:translateY(28px);transition:opacity .8s var(--ease),transform .8s var(--ease)}
.rv.in{opacity:1;transform:none}

/* ---------- 顶部导航 ---------- */
.site-header{
  position:fixed;inset:0 0 auto 0;z-index:999;height:var(--header-h);
  transition:background .4s var(--ease),box-shadow .4s var(--ease),border-color .4s var(--ease);
  border-bottom:1px solid transparent;
}
.site-header.scrolled{
  background:rgba(11,11,12,.86);backdrop-filter:blur(14px);-webkit-backdrop-filter:blur(14px);
  border-bottom-color:var(--line);box-shadow:0 10px 30px rgba(0,0,0,.35);
}
.header-inner{height:100%;display:flex;align-items:center;justify-content:space-between;gap:20px;width:min(1280px,94%);margin-inline:auto}
.brand{display:flex;align-items:center;gap:12px;flex:none}
.brand img{width:44px;height:44px;object-fit:cover;border-radius:6px}
.brand-name{font-size:20px;font-weight:900;letter-spacing:.02em;line-height:1.1;display:flex;flex-direction:column}
.brand-name small{font-size:11px;font-weight:500;color:var(--muted-dark);letter-spacing:.22em;margin-top:3px}
.main-nav{display:flex;align-items:center}
.main-nav>ul{display:flex;align-items:center;gap:4px}
.nav-link{
  display:block;padding:10px 14px;font-size:15px;font-weight:600;color:#d9d9d4;
  border-radius:4px;transition:.3s var(--ease);position:relative;
}
.nav-link:hover{color:#fff;background:rgba(255,255,255,.06)}
.nav-link.active{color:#fff}
.nav-link.active::after{
  content:"";position:absolute;left:14px;right:14px;bottom:5px;height:2px;background:#fff;
}
.has-drop{position:relative}
.has-drop>.nav-link .caret{display:inline-block;width:0;height:0;border-left:5px solid transparent;border-right:5px solid transparent;border-top:6px solid currentColor;margin-left:7px;vertical-align:2px;transition:.3s}
.has-drop:hover>.nav-link .caret{transform:rotate(180deg)}
.drop{
  position:absolute;top:calc(100% + 10px);left:50%;transform:translateX(-50%) translateY(8px);
  min-width:190px;background:rgba(19,19,21,.97);backdrop-filter:blur(16px);
  border:1px solid var(--line);border-radius:8px;padding:10px;opacity:0;visibility:hidden;
  transition:.3s var(--ease);box-shadow:0 24px 50px rgba(0,0,0,.5);
}
.has-drop:hover .drop{opacity:1;visibility:visible;transform:translateX(-50%) translateY(0)}
.drop a{
  display:block;padding:9px 14px;font-size:14px;color:#c9c9c4;border-radius:4px;transition:.25s;
}
.drop a:hover{color:#fff;background:rgba(255,255,255,.08);padding-left:20px}
.header-actions{display:flex;align-items:center;gap:14px;flex:none}
.header-tel{
  display:flex;align-items:center;gap:8px;font-size:15px;font-weight:800;color:#fff;
  padding:9px 16px;border:1px solid var(--line);border-radius:999px;transition:.3s var(--ease);
}
.header-tel:hover{border-color:#fff;background:rgba(255,255,255,.07)}
.hamburger{display:none;flex-direction:column;gap:5px;padding:10px;z-index:1002}
.hamburger span{width:24px;height:2px;background:#fff;transition:.35s var(--ease);border-radius:2px}
.hamburger.open span:nth-child(1){transform:translateY(7px) rotate(45deg)}
.hamburger.open span:nth-child(2){opacity:0}
.hamburger.open span:nth-child(3){transform:translateY(-7px) rotate(-45deg)}

/* ---------- 页脚 ---------- */
.site-footer{position:relative;background:var(--ink);border-top:1px solid var(--line);padding:72px 0 0;overflow:hidden}
.footer-main{display:grid;grid-template-columns:1.5fr 1fr 1fr 1.2fr;gap:44px;padding-bottom:56px}
.footer-brand img{width:52px;height:52px;object-fit:cover;border-radius:8px;margin-bottom:16px}
.footer-brand h3{font-size:19px;font-weight:800;margin-bottom:12px}
.footer-brand p{font-size:14px;color:var(--muted-dark);max-width:320px}
.footer-col h4{font-size:14px;font-weight:700;letter-spacing:.14em;margin-bottom:18px;color:#fff}
.footer-col a{
  display:block;font-size:14px;color:var(--muted-dark);padding:6px 0;transition:.25s;width:fit-content;
}
.footer-col a:hover{color:#fff;transform:translateX(4px)}
.footer-contact li{display:flex;gap:12px;align-items:flex-start;padding:8px 0;font-size:14px;color:var(--muted-dark)}
.footer-contact svg{flex:none;margin-top:4px;color:#fff}
.footer-contact a:hover{color:#fff}
.footer-bottom{
  display:flex;align-items:center;justify-content:space-between;gap:16px;flex-wrap:wrap;
  border-top:1px solid var(--line);padding:22px 0 26px;font-size:13px;color:var(--muted-dark);
}
.footer-bottom a:hover{color:#fff}

/* ---------- 悬浮元素 ---------- */
.back-top{
  position:fixed;right:26px;bottom:92px;z-index:900;width:46px;height:46px;border-radius:50%;
  background:#fff;color:#000;display:flex;align-items:center;justify-content:center;
  box-shadow:0 12px 30px rgba(0,0,0,.4);opacity:0;visibility:hidden;transform:translateY(12px);
  transition:.35s var(--ease);
}
.back-top.show{opacity:1;visibility:visible;transform:none}
.back-top:hover{background:#e7e7e2}
.float-tel{
  position:fixed;right:26px;bottom:28px;z-index:900;display:flex;align-items:center;gap:9px;
  background:#fff;color:#000;font-weight:800;font-size:15px;padding:13px 22px;border-radius:999px;
  box-shadow:0 14px 36px rgba(0,0,0,.45);transition:.3s var(--ease);
}
.float-tel:hover{transform:translateY(-3px);box-shadow:0 20px 44px rgba(0,0,0,.5)}

/* ---------- 表单基础 ---------- */
.lmnt-toast{
  position:fixed;left:50%;bottom:48px;transform:translateX(-50%) translateY(20px);z-index:2000;
  background:#fff;color:#0b0b0c;font-size:14px;font-weight:700;padding:14px 26px;border-radius:6px;
  box-shadow:0 18px 44px rgba(0,0,0,.45);opacity:0;visibility:hidden;transition:.35s var(--ease);
  max-width:90%;text-align:center;
}
.lmnt-toast.show{opacity:1;visibility:visible;transform:translateX(-50%) translateY(0)}
.form-grid{display:grid;grid-template-columns:1fr 1fr;gap:18px}
.form-item{display:flex;flex-direction:column;gap:8px}
.form-item label{font-size:13px;font-weight:700;letter-spacing:.06em}
.form-item input,.form-item select,.form-item textarea{
  background:rgba(255,255,255,.05);border:1px solid var(--line);border-radius:6px;
  padding:13px 16px;color:#fff;outline:none;transition:.3s;width:100%;
}
.form-item input:focus,.form-item select:focus,.form-item textarea:focus{border-color:#fff;background:rgba(255,255,255,.08)}
.form-item textarea{resize:vertical;min-height:110px}
.form-item select option{background:#1c1c1f;color:#fff}
.form-item input::placeholder,.form-item textarea::placeholder{color:#6e6e68}
.form-tip{font-size:12px;color:var(--muted-dark)}

/* ---------- 面包屑 ---------- */
.crumbs{display:flex;flex-wrap:wrap;gap:8px;font-size:13px;color:var(--muted-dark);align-items:center}
.crumbs a:hover{color:#fff}
.crumbs .sep{color:#555}

/* ---------- 响应式 ---------- */
@media (max-width:1080px){
  .main-nav{position:fixed;inset:0;background:rgba(11,11,12,.98);backdrop-filter:blur(18px);
    flex-direction:column;align-items:flex-start;justify-content:flex-start;
    padding:110px 8% 40px;transform:translateX(100%);transition:transform .45s var(--ease);overflow-y:auto;z-index:1000}
  .nav-open .main-nav{transform:none}
  .main-nav>ul{flex-direction:column;align-items:stretch;width:100%;gap:2px}
  .nav-link{padding:14px 8px;font-size:17px}
  .nav-link.active::after{display:none}
  .has-drop .drop{
    position:static;transform:none;opacity:1;visibility:visible;min-width:0;
    background:transparent;border:0;box-shadow:none;padding:0 0 6px 18px;display:none;
  }
  .has-drop .drop.open{display:block}
  .has-drop:hover .drop{transform:none}
  .hamburger{display:flex}
  .footer-main{grid-template-columns:1fr 1fr;gap:36px}
}
@media (max-width:640px){
  .section{padding:64px 0}
  .sec-head{flex-direction:column;align-items:flex-start;margin-bottom:36px}
  .header-tel span{display:none}
  .footer-main{grid-template-columns:1fr;gap:30px}
  .footer-bottom{flex-direction:column;align-items:flex-start}
  .form-grid{grid-template-columns:1fr}
  .back-top{right:16px;bottom:96px}
  .float-tel{right:16px;bottom:26px;padding:12px 16px;font-size:14px}
}
@media (prefers-reduced-motion:reduce){
  *,*::before,*::after{transition:none!important;animation:none!important}
  .rv{opacity:1;transform:none}
  .hw{opacity:1;transform:none}
  html{scroll-behavior:auto}
}