/* =========================================================
   IAIA 全站通用样式
   包含：基础重置 + 页头(sh) + 页脚(sf) + 多语言 + 断点
   ========================================================= */

/* ========== CSS 变量 ========== */
:root{
  --navy:#0b2545;
  --navy-2:#13335c;
  --ink:#16202e;
  --muted:#5b6b7d;
  --line:#e3e8ee;
  --bg:#ffffff;
  --bg-soft:#f5f7fa;
  --gold:#b8893a;
  --gold-soft:#f3ead6;
  --blue:#1f5fa8;
  --maxw:1180px;
}

/* ========== 全局重置 ========== */
*{box-sizing:border-box;margin:0;padding:0;}
html{scroll-behavior:smooth;}
body{
  font-family:"Inter","Segoe UI",-apple-system,BlinkMacSystemFont,"PingFang SC","Hiragino Sans GB","Microsoft YaHei","Noto Sans CJK SC","Noto Sans CJK TC",sans-serif;
  color:var(--ink);
  background:var(--bg);
  line-height:1.65;
  -webkit-font-smoothing:antialiased;
}
a{color:inherit;text-decoration:none;}
img{max-width:100%;height:auto;display:block;}
button{font-family:inherit;}

.container{max-width:var(--maxw);margin:0 auto;padding:0 28px;}

/* =========================================================
   全站通用顶栏 .sh
   ========================================================= */
.sh{background:#fff;border-bottom:1px solid var(--line);position:sticky;top:0;z-index:200;}
.sh-in{max-width:var(--maxw);margin:0 auto;padding:0 28px;display:flex;align-items:center;gap:26px;height:92px;}
.sh-logo{flex:0 0 auto;display:flex;align-items:center;}
.sh-logo img{height:60px;width:auto;display:block;}
.sh-nav{display:flex;align-items:center;gap:2px;flex:1 1 auto;}
.sh-item{position:relative;}
.sh-item > a{display:flex;align-items:center;gap:5px;font-size:14.5px;font-weight:500;color:var(--ink);
  letter-spacing:.02em;padding:34px 14px;border-bottom:2px solid transparent;transition:.15s;white-space:nowrap;}
.sh-item > a .chev{width:9px;height:9px;border-right:1.6px solid currentColor;border-bottom:1.6px solid currentColor;
  transform:rotate(45deg) translate(-1px,-1px);margin-left:1px;opacity:.55;transition:.15s;}
.sh-item:hover > a,.sh-item > a.active{color:var(--navy);border-bottom-color:var(--gold);}
.sh-item:hover > a .chev{transform:rotate(225deg) translate(-2px,-2px);}

/* 二级下拉 */
.sh-sub{position:absolute;top:100%;left:0;background:#fff;border:1px solid var(--line);
  border-radius:14px;box-shadow:0 20px 52px rgba(11,37,69,.15);padding:24px 26px 20px;display:none;z-index:300;}
.sh-item:hover .sh-sub{display:block;}
.sh-sub-cols{display:grid;gap:6px 26px;}
.sh-sub-cols.c1{grid-template-columns:minmax(190px,1fr);}
.sh-sub-cols.c2{grid-template-columns:repeat(2,minmax(170px,1fr));}
.sh-sub-cols.c3{grid-template-columns:repeat(3,minmax(190px,1fr));}
.sh-sub-cols.c4{grid-template-columns:repeat(4,minmax(150px,1fr));}
.sh-col-h{display:block;font-size:11px;letter-spacing:.14em;text-transform:uppercase;
  color:var(--gold);font-weight:700;margin-bottom:9px;padding-bottom:7px;border-bottom:1px solid var(--line);}
.sh-sub .sh-grp{display:block;font-size:11.5px;font-weight:700;letter-spacing:.06em;color:var(--ink);
  margin:11px 0 3px;padding:9px 0 0 0;border-top:1px solid var(--line);}
.sh-sub a{display:block;font-size:13.5px;color:var(--muted);padding:5px 0;transition:.14s;white-space:nowrap;}
.sh-sub a.sh-ind{padding-left:13px;position:relative;}
.sh-sub a.sh-ind:before{content:"";position:absolute;left:3px;top:12px;width:5px;height:5px;
  border-radius:50%;background:var(--gold);opacity:.7;}
.sh-sub a:hover{color:var(--navy);}

/* 三级飞入 */
.sh-fly{position:relative;}
.sh-fly-t{display:flex;align-items:center;justify-content:space-between;gap:8px;font-size:13.5px;
  color:var(--muted);padding:5px 0;transition:.14s;white-space:nowrap;cursor:default;}
.sh-fly-t .sh-fly-c{width:6px;height:6px;border-right:1.4px solid currentColor;border-top:1.4px solid currentColor;
  transform:rotate(45deg);opacity:.6;flex:0 0 auto;margin-right:3px;transition:.15s;}
.sh-fly:hover .sh-fly-t{color:var(--navy);}
.sh-fly-p{display:none;position:absolute;left:calc(100% + 10px);top:-10px;min-width:218px;background:#fff;
  border:1px solid var(--line);border-radius:12px;box-shadow:0 18px 44px rgba(11,37,69,.16);
  padding:12px 16px 14px;z-index:320;}
.sh-fly-p:before{content:"";position:absolute;left:-11px;top:0;width:12px;height:100%;}
.sh-fly:hover .sh-fly-p,.sh-fly:focus-within .sh-fly-p{display:block;}
.sh-fly-p a{display:block;font-size:13.5px;color:var(--muted);padding:5px 0;transition:.14s;white-space:nowrap;}
.sh-fly-p a:hover{color:var(--navy);}

/* 右侧功能区 */
.sh-right{display:flex;align-items:center;gap:12px;flex:0 0 auto;}

/* 语言切换 */
.sh-lang{position:relative;}
.sh-lang-btn{display:flex;align-items:center;justify-content:space-between;gap:9px;min-width:106px;
  border:1px solid var(--line);background:#fff;border-radius:8px;padding:8px 12px;font-size:13px;
  color:var(--ink);cursor:pointer;font-family:inherit;line-height:1.2;}
.sh-lang-btn .caret{flex:0 0 auto;width:0;height:0;border-left:4px solid transparent;border-right:4px solid transparent;
  border-top:5px solid var(--muted);}
.sh-lang-btn:hover{border-color:var(--navy);}
.sh-lang-menu{position:absolute;top:calc(100% + 7px);right:0;background:#fff;border:1px solid var(--line);
  border-radius:10px;box-shadow:0 16px 40px rgba(11,37,69,.14);min-width:140px;padding:6px;display:none;z-index:310;}
.sh-lang.open .sh-lang-menu{display:block;}
.sh-lang-menu button{display:block;width:100%;text-align:left;border:0;background:none;padding:8px 11px;
  font-size:13px;color:var(--muted);border-radius:6px;cursor:pointer;font-family:inherit;}
.sh-lang-menu button:hover{background:var(--bg-soft);color:var(--navy);}
.sh-lang-menu button.active{color:var(--navy);font-weight:600;background:var(--bg-soft);}

/* 登录/加入/账户 */
.sh-login{font-size:13.5px;color:var(--navy);font-weight:500;padding:9px 10px;white-space:nowrap;}
.sh-login:hover{color:var(--gold);}
.sh-join{background:var(--navy);color:#fff;font-size:13.5px;font-weight:600;padding:10px 18px;
  border-radius:8px;letter-spacing:.02em;white-space:nowrap;transition:.16s;display:inline-block;}
.sh-join:hover{background:var(--navy-2);}
.sh-acc{display:none;align-items:center;gap:8px;}
body.acc-in .sh-acc{display:flex;}
body.acc-in .sh-right > .sh-login,body.acc-in .sh-right > .sh-join{display:none;}
.sh-acc-b{font-size:13.5px;font-weight:600;color:var(--navy);padding:9px 14px;border-radius:8px;
  background:var(--bg-soft);white-space:nowrap;transition:.16s;display:inline-block;}
.sh-acc-b:hover{background:#e9eef5;}
.sh-acc-o{border:1px solid var(--line);background:#fff;border-radius:8px;padding:9px 13px;font-size:13px;
  color:var(--muted);font-family:inherit;cursor:pointer;white-space:nowrap;transition:.16s;display:inline-block;}
.sh-acc-o:hover{border-color:var(--navy);color:var(--navy);}

/* 汉堡按钮 */
.sh-burger{display:none;width:42px;height:38px;border:1px solid var(--line);border-radius:8px;background:#fff;
  cursor:pointer;flex-direction:column;align-items:center;justify-content:center;gap:4px;padding:0;}
.sh-burger span{display:block;width:18px;height:2px;background:var(--navy);border-radius:2px;transition:.2s;}
.sh-burger.on span:nth-child(1){transform:translateY(6px) rotate(45deg);}
.sh-burger.on span:nth-child(2){opacity:0;}
.sh-burger.on span:nth-child(3){transform:translateY(-6px) rotate(-45deg);}

/* ========== 移动端抽屉 ========== */
.sh-drawer{display:none;position:fixed;top:92px;left:0;right:0;bottom:0;background:#fff;z-index:190;
  overflow-y:auto;padding-bottom:40px;border-top:1px solid var(--line);}
.sh-drawer.on{display:block;}
.sh-dl{border-bottom:1px solid var(--line);}
.sh-dl > a,.sh-dl > button{display:flex;align-items:center;justify-content:space-between;width:100%;
  text-align:left;background:none;border:0;padding:16px 28px;font-size:15.5px;font-weight:600;
  color:var(--navy);font-family:inherit;cursor:pointer;letter-spacing:.02em;}
.sh-dl > button .pm{font-size:18px;font-weight:400;color:var(--muted);}
.sh-dsub{display:none;padding:0 28px 16px;}
.sh-dsub.on{display:block;}
.sh-dsub-h{display:block;font-size:11px;letter-spacing:.14em;text-transform:uppercase;color:var(--gold);
  font-weight:700;padding:12px 0 5px;}
.sh-dsub a{display:block;padding:8px 0;font-size:14px;color:var(--muted);}
.sh-dsub .sh-dgrp{display:block;font-size:12px;font-weight:700;color:var(--navy);
  padding:12px 0 4px;margin-top:4px;border-top:1px solid var(--line);letter-spacing:.04em;}
.sh-dsub a.sh-dind{padding-left:12px;}
.sh-dauth{display:flex;gap:10px;padding:22px 28px 14px;}
.sh-dauth .sh-login,.sh-dauth .sh-join{flex:1;text-align:center;padding:13px 10px;border-radius:8px;}
.sh-dauth .sh-login{border:1px solid var(--line);color:var(--navy);}
.sh-dauth-acc{display:none;gap:10px;padding:22px 28px 14px;}
body.acc-in .sh-dauth-acc{display:flex;}
body.acc-in .sh-dauth{display:none;}
.sh-dauth-acc .sh-acc-b,.sh-dauth-acc .sh-acc-o{flex:1;text-align:center;padding:13px 10px;border-radius:8px;}
.sh-dlang{display:flex;gap:8px;padding:0 28px 22px;flex-wrap:wrap;}
.sh-dlang button{border:1px solid var(--line);background:#fff;border-radius:8px;padding:9px 15px;
  font-size:13px;color:var(--muted);font-family:inherit;cursor:pointer;}
.sh-dlang button.active{background:var(--navy);border-color:var(--navy);color:#fff;font-weight:600;}

/* =========================================================
   全站通用页脚 .sf
   ========================================================= */
.sf{background:#0a1d36;color:#aebccd;padding:60px 0 28px;font-size:14px;}
.sf-in{max-width:var(--maxw);margin:0 auto;padding:0 28px;}
.sf-cols{display:grid;grid-template-columns:1.55fr 1fr 1fr 1fr;gap:40px;}
.sf h4{color:#fff;font-size:15px;font-weight:600;letter-spacing:.04em;margin-bottom:18px;}
.sf a{color:#aebccd;display:block;margin-bottom:10px;font-size:13.8px;transition:.14s;}
.sf a:hover{color:#fff;}
.sf-brand .sf-mark{font-size:25px;font-weight:700;color:#fff;letter-spacing:.07em;line-height:1;}
.sf-brand .sf-org{font-size:13.8px;color:#cdd8e6;margin:12px 0 18px;letter-spacing:.02em;}
.sf-brand p{margin-bottom:9px;font-size:13.4px;line-height:1.62;}
.sf-brand b{color:#8fa3bb;font-weight:600;margin-right:5px;}
.sf-brand a{display:inline;color:#cdd8e6;}
.sf-bottom{border-top:1px solid rgba(255,255,255,.12);margin-top:44px;padding-top:20px;
  color:#7e8da0;font-size:13px;letter-spacing:.02em;}

/* =========================================================
   多语言显隐
   ========================================================= */
body.lang-en .lang-zh,body.lang-en .lang-tw{display:none;}
body.lang-zh .lang-en,body.lang-zh .lang-tw{display:none;}
body.lang-tw .lang-en,body.lang-tw .lang-zh{display:none;}

/* =========================================================
   断点：1080 / 900 / 760
   ========================================================= */
@media(max-width:1080px){
  .sh-nav,.sh-right .sh-lang,.sh-right .sh-login{display:none;}
  .sh-burger{display:flex;}
  .sf-cols{grid-template-columns:1fr 1fr;gap:34px;}
}
@media(max-width:900px){
  /* 页面级样式由各页面自行定义 */
}
@media(max-width:760px){
  .sh-in{height:72px;padding:0 18px;gap:12px;}
  .sh-logo img{height:46px;}
  .sh-drawer{top:72px;}
  .container{padding:0 20px;}
  .sf-cols{grid-template-columns:1fr;gap:30px;}
}