/* renshikaoshi.com 基础样式
   设计系统见 design/02-UI设计规范.md，全站复用，不新增色值 */
:root{
  --blue:#2563EB; --blue-d:#1E40AF; --blue-l:#EFF6FF; --ink:#0F172A;
  --cyan:#06B6D4; --orange:#F97316; --orange-l:#FB923C;
  --t1:#0F172A; --t2:#475569; --t3:#94A3B8; --line:#E2E8F0; --bg:#F8FAFC;
  --green:#047857; --green-l:#ECFDF5;
  --r:14px; --r-lg:20px;
  --sh:0 1px 2px rgba(15,23,42,.04), 0 8px 24px rgba(15,23,42,.06);
  --sh-lg:0 4px 12px rgba(15,23,42,.06), 0 24px 48px rgba(15,23,42,.10);
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{font-family:-apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei","Segoe UI",Roboto,sans-serif;
  color:var(--t1);background:#fff;line-height:1.6;-webkit-font-smoothing:antialiased}
a{color:inherit;text-decoration:none}
img{display:block;max-width:100%}
button{font-family:inherit;cursor:pointer;border:none;background:none;font-size:inherit}
input,select,textarea{font-family:inherit}
.wrap{width:100%;max-width:1200px;margin:0 auto;padding:0 24px}
.mid{width:100%;max-width:880px;margin:0 auto;padding:0 24px}

.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;height:48px;padding:0 26px;
  border-radius:12px;font-size:15px;font-weight:500;transition:.18s;white-space:nowrap}
.btn-main{background:linear-gradient(135deg,#FB923C,#F97316);color:#fff;box-shadow:0 6px 18px rgba(249,115,22,.28)}
.btn-main:hover{transform:translateY(-1px);box-shadow:0 10px 26px rgba(249,115,22,.36)}
.btn-blue{background:var(--blue);color:#fff;box-shadow:0 6px 18px rgba(37,99,235,.24)}
.btn-blue:hover{background:var(--blue-d);transform:translateY(-1px)}
.btn-ghost{background:#fff;color:var(--t1);border:1px solid var(--line)}
.btn-ghost:hover{border-color:#CBD5E1;background:var(--bg)}
.btn-lg{height:56px;font-size:16px;padding:0 34px;border-radius:14px}
.btn-sm{height:38px;padding:0 18px;font-size:14px;border-radius:10px}
.btn-block{display:flex;width:100%}
.btn:disabled{opacity:.55;cursor:not-allowed;transform:none}

/* 导航 */
.nav{position:sticky;top:0;z-index:60;background:rgba(255,255,255,.88);backdrop-filter:blur(12px);
  border-bottom:1px solid var(--line)}
.nav-in{display:flex;align-items:center;height:64px;gap:36px}
.logo{display:flex;align-items:center;gap:10px;font-size:18px;font-weight:600;letter-spacing:-.2px}
.logo-m{width:32px;height:32px;border-radius:9px;background:linear-gradient(135deg,#2563EB,#06B6D4);
  display:flex;align-items:center;justify-content:center;color:#fff;font-size:15px;font-weight:600}
.nav-links{display:flex;gap:28px;font-size:15px;color:var(--t2)}
.nav-links a:hover{color:var(--blue)}
.nav-cta{margin-left:auto;display:flex;align-items:center;gap:12px}

/* 表单控件 */
.field{margin-bottom:14px}
.field label{display:block;font-size:13px;color:var(--t2);margin-bottom:6px;font-weight:500}
select,input[type=text],input[type=tel],input[type=password]{width:100%;height:46px;padding:0 13px;
  border:1px solid var(--line);border-radius:10px;font-size:14px;color:var(--t1);background:#fff;
  outline:none;transition:.15s}
select:focus,input:focus{border-color:var(--blue);box-shadow:0 0 0 3px rgba(37,99,235,.12)}

/* 通用区块 */
.sec-head{text-align:center;max-width:660px;margin:0 auto 40px}
.sec-head h2{font-size:32px;font-weight:600;letter-spacing:-.6px;margin-bottom:12px}
.sec-head p{font-size:16px;color:var(--t2)}
.tag{display:inline-flex;align-items:center;gap:5px;font-size:12px;padding:4px 10px;border-radius:6px;
  background:var(--blue-l);color:var(--blue)}
.tag-green{background:var(--green-l);color:var(--green)}
.tag-gray{background:var(--bg);color:var(--t3)}

/* 页脚 */
footer{background:#0B1220;color:#8FA0BE;padding:44px 0 32px;font-size:13px;margin-top:0}
.foot-in{display:grid;grid-template-columns:2fr 1fr 1fr 1fr;gap:32px;margin-bottom:28px}
footer h4{color:#fff;font-size:14px;font-weight:500;margin-bottom:14px}
footer a{display:block;padding:5px 0;color:#8FA0BE}
footer a:hover{color:#fff}
.foot-b{border-top:1px solid rgba(255,255,255,.08);padding-top:20px;display:flex;gap:16px;flex-wrap:wrap}

/* 深色 CTA 区 */
.dark{background:linear-gradient(135deg,#0F172A,#1E3A8A);color:#fff;position:relative;overflow:hidden}
.dark::after{content:"";position:absolute;inset:0;
  background:radial-gradient(520px 300px at 50% 0%,rgba(6,182,212,.22),transparent 70%)}
.dark>*{position:relative;z-index:2}

@media(max-width:1024px){
  .nav-links{display:none}
  .foot-in{grid-template-columns:1fr 1fr}
}
@media(max-width:640px){
  .wrap,.mid{padding:0 16px}
  .sec-head h2{font-size:25px}
  .foot-in{grid-template-columns:1fr}
}

/* 登录注册弹窗（全站公共组件） */
.mask{position:fixed;inset:0;background:rgba(15,23,42,.55);z-index:100;display:none;
  align-items:center;justify-content:center;padding:20px;backdrop-filter:blur(3px)}
.mask.on{display:flex}
.modal{background:#fff;border-radius:var(--r-lg);width:100%;max-width:420px;padding:28px;position:relative;
  box-shadow:0 24px 60px rgba(2,6,23,.35);max-height:92vh;overflow:auto}
.modal .close{position:absolute;right:16px;top:14px;width:30px;height:30px;border-radius:8px;
  color:var(--t3);display:flex;align-items:center;justify-content:center;font-size:20px}
.modal .close:hover{background:var(--bg);color:var(--t1)}
.modal h3{font-size:20px;font-weight:600;margin-bottom:6px}
.modal .msub{font-size:13px;color:var(--t3);margin-bottom:18px}
.perks{background:var(--bg);border-radius:12px;padding:14px 16px;margin-bottom:18px}
.perks li{list-style:none;display:flex;gap:8px;font-size:13px;color:var(--t2);padding:3px 0}
.perks li b{color:var(--green);font-weight:600}
.tabs{display:flex;gap:6px;background:var(--bg);border-radius:10px;padding:4px;margin-bottom:18px}
.tabs button{flex:1;height:36px;border-radius:8px;font-size:14px;color:var(--t2)}
.tabs button.on{background:#fff;color:var(--t1);box-shadow:var(--sh);font-weight:500}
.err{font-size:13px;color:#DC2626;margin-bottom:10px;display:none}
.err.on{display:block}

/* 会员入口（导航高亮） */
.nav-vip{color:var(--orange)!important;font-weight:600;display:inline-flex;align-items:center;gap:4px}
.nav-vip::after{content:"VIP";font-size:10px;padding:1px 5px;border-radius:4px;background:#FFF7ED;
  border:1px solid #FED7AA;color:var(--orange);font-weight:600}
.nav-vip:hover{color:#EA580C!important}