/* ============================================================
   智学云 · 统一站点导航样式（单一真源）
   仅作用于 .nav / .mobile-menu，变量作用域隔离，
   不会污染页面正文样式。所有静态页统一加载本文件。
   ============================================================ */
.nav, .mobile-menu{
  --navy:#0d1730;
  --navy-2:#14213f;
  --navy-line:rgba(13,23,48,.10);
  --gold:#b8893e;
  --gold-2:#d6a85c;
  --gold-deep:#8a6428;
  --gold-soft:rgba(184,137,62,.12);
  --ink:#16203a;
  --ink-mid:#41506e;
  --ink-soft:#3a445c;
  --ease:cubic-bezier(.22,.61,.36,1);
}

/* 顶部滚动进度条（与 motion.css 同源，缺省也有） */
.scroll-progress{position:fixed;top:0;left:0;height:3px;width:100%;transform:scaleX(0);transform-origin:left;z-index:90;
  background:linear-gradient(90deg,var(--gold),var(--gold-2));transition:transform .08s linear}

.nav .wrap, .nav.wrap{max-width:1300px;margin:0 auto;padding:0 34px}
/* 明亮配色方案 A · 晨曦蓝：#f7f9fc 冷调浅瓷白玻璃底 + 蓝/青微光 */
header.nav{position:sticky;top:0;z-index:50;isolation:isolate;
  --grid-color:rgba(13,23,48,.05);  /* 与「统一接入」模块一致：启用全局网格，密度/线色统一 */
  background:
    radial-gradient(120% 240% at 6% -80%, rgba(184,137,62,.12), transparent 60%),
    radial-gradient(120% 260% at 96% -60%, rgba(184,137,62,.14), transparent 58%),
    rgba(255,255,255,.82);           /* 提到白玻璃档：拉开与 hero #f4f7fd 的明度差，让 blur 有对比物 */
  -webkit-backdrop-filter:saturate(160%) blur(14px);backdrop-filter:saturate(160%) blur(14px);
  box-shadow:0 10px 30px -16px rgba(13,23,48,.18);   /* 投影改正值扩展：让导航栏浮在 hero 之上 */
  border-bottom:1px solid rgba(13,23,48,.10);         /* 常驻 1px 细分割线：金线仅作强调态（见 ::after） */
  transition:box-shadow .35s var(--ease)}
/* 导航栏背景 · 静态品牌微光（方案 C · 全静态克制）
   双角暗金单色微光，无呼吸 / 无漂移 / 无 16s 动画，去除蓝角与科技 Demo 感；
   与英雄区底部暗金网格、金线语言同源；金线(::after)仍保留滚动显现微互动；
   堆叠层级：网格(-1) < 本层(0) < 内容(.nav-inner,1) < 金线(::after,2) */
header.nav::before{content:"";position:absolute;inset:0;z-index:0;pointer-events:none;
  background:
    radial-gradient(58% 220% at 14% -40%, rgba(184,137,62,.11), transparent 60%),
    radial-gradient(50% 200% at 88% -30%, rgba(184,137,62,.11), transparent 58%);
  opacity:.55;transform:translate3d(0,0,0) scale(1)}
/* 底部 2px 渐变金线收口：与 logo 金标 / 金 CTA 同源（暗金细线点缀）；
   默认隐藏，滚动后 scaleX 显现（方案 C 微互动）；prefers-reduced-motion 下常驻可见 */
header.nav::after{content:"";position:absolute;left:0;right:0;bottom:0;height:2px;z-index:2;pointer-events:none;
  background:linear-gradient(90deg,rgba(184,137,62,0),rgba(184,137,62,.95) 50%,rgba(184,137,62,0));
  transform:scaleX(0);opacity:0;transform-origin:center;
  transition:transform .4s var(--ease),opacity .4s var(--ease)}
header.nav.scrolled::after{transform:scaleX(1);opacity:1}
/* 导航栏网格背景已统一交由全局 .gx-grid::before（theme.css）按 --grid* 变量绘制，
   锚定视口、与英雄区 / 统一接入模块共用同一坐标系，避免原 34px 与英雄区 42px 错配导致竖线错位 */
.nav-inner{display:flex;align-items:center;justify-content:center;gap:20px;height:68px;position:relative;z-index:1}
.logo{display:flex;flex:0 0 auto;align-items:center;gap:14px;color:#0d1730;text-decoration:none}
.logo .mark{width:36px;height:36px;border-radius:9px;display:grid;place-items:center;
  background:linear-gradient(135deg,var(--gold),var(--gold-2));color:#1a1304;font-family:"Noto Serif SC";font-weight:700;font-size:19px}
.logo img.logo-mark{width:38px;height:38px;border-radius:10px;object-fit:cover;display:block;
  box-shadow:0 6px 16px rgba(0,0,0,.22)}
/* 品牌名：横向单行 · 华文行楷（楷体 → 衬线逐级回退，未装也能正常显示）
   配色改用金色系，与导航内的金色标识、金色 CTA 同源，冷调浅瓷白底上暖金更"搭"：
   默认古铜金 #8a6428（5.06:1）→ 悬停深金 #7a5520（6.33:1，与 logo 主色同金相、更深更饱和，醒目且过 AA）→ 激活墨棕 #4a3413（11.11:1）；
   悬停/键盘聚焦另加一条 logo 主色 #b8893e 的 2px 下划线由左向右擦入（纯装饰，不损文字对比），使「智学云」悬停态一眼可辨、且与激活态明确区分
   （原默认 #0d1730 相对亮度仅 0.9，视觉等同纯黑，故弃用；金色文字的浅色上限即 #8a6428，再浅会跌破 4.5）
   注：translateY(1.5px) 用于补偿行楷字形重心偏上——实测墨迹中心比标识中心高 1.5px */
.logo-txt{writing-mode:horizontal-tb;text-orientation:mixed;white-space:nowrap;line-height:1;letter-spacing:1.5px;
  transform:translateY(1.5px)}
.logo-txt b{font-family:"华文行楷","STXingkai","华文楷体","STKaiti","楷体","KaiTi","Kaiti SC","楷体_GB2312","SimKai","Noto Serif SC","Noto Serif CJK SC",serif;
  font-size:22px;font-weight:600;
  display:block;line-height:1;white-space:nowrap;
  color:#8a6428;transition:color .28s var(--ease)}
.logo:hover .logo-txt b,.logo:focus-visible .logo-txt b{color:var(--gold)}
.logo:active .logo-txt b{color:#4a3413}
.logo:focus-visible{outline:2px solid var(--gold-deep);outline-offset:5px;border-radius:8px}
.logo-txt small{font-size:11px;color:rgba(13,23,48,.55);letter-spacing:.08em;writing-mode:horizontal-tb}
.main{flex:0 0 auto;display:flex;align-items:center}
.nav-menu{display:flex;gap:12px;list-style:none;margin:0;padding:0}
.nav-link{display:block;padding:8px 10px;border-radius:9px;color:#41506e;font-size:14px;
  font-weight:400;transition:color .25s,background .25s;position:relative;text-decoration:none;white-space:nowrap}
.nav-link:hover,.nav-link.active{color:#0d1730;background:rgba(13,23,48,.055)}
/* 选中一级标题时标题下端的暗金高亮指示线（与 header.nav::after 底部金线同源）；
   默认隐藏，hover 弱显、active 全显（方案 C 微互动）。仅作用于一级 .nav-link，
   不影响下拉二级项（.dropdown .dp-list a 独立左指示）。light-surface.css 的
   !important 仅覆盖 background/color，未定义 ::after，故本规则不被覆盖。 */
.nav-link::after{content:"";position:absolute;left:10px;right:10px;bottom:5px;height:2px;border-radius:2px;
  background:linear-gradient(90deg,rgba(184,137,62,0),var(--gold) 50%,rgba(184,137,62,0));
  opacity:0;transform:scaleX(.35);transform-origin:center;pointer-events:none;
  transition:transform .32s var(--ease),opacity .32s var(--ease)}
.nav-link:hover::after{opacity:.5;transform:scaleX(.72)}
.nav-link.active::after{opacity:1;transform:scaleX(1)}
.nav-login{color:#41506e;font-size:14.5px;padding:8px 4px;text-decoration:none;white-space:nowrap}
.nav-login:hover{color:var(--gold-deep)}
.nav-cta{background:linear-gradient(135deg,var(--gold),var(--gold-2));color:#1a1304;font-weight:700;
  padding:10px 18px;border-radius:10px;font-size:14.5px;transition:transform .3s var(--ease);text-decoration:none;white-space:nowrap}
.nav-cta:hover{transform:translateY(-2px)}
.nav-search{position:relative;display:flex;align-items:center;border:none;background:transparent}
.nav-search .s-field{display:flex;align-items:center;gap:6px;width:100px;height:30px;padding:0 10px;
  background:rgba(255,255,255,.92);border:1px solid rgba(13,23,48,.18);border-radius:9px;cursor:text;
  box-shadow:0 1px 2px rgba(13,23,48,.06);
  transition:border-color .25s var(--ease),box-shadow .25s var(--ease),width .3s var(--ease),background .25s var(--ease)}
/* 聚焦态：藏青主色描边 + 柔和藏青聚焦环（替代原金色，消除突兀黄色）；
   鼠标点击与键盘 Tab 聚焦均会触发 :focus-within，保留清晰的无障碍指示 */
.nav-search .s-field:focus-within{border-color:var(--ink);box-shadow:0 0 0 3px rgba(13,23,48,.16)}
/* 去除本项目全局/浏览器默认落在搜索框上的金色聚焦描边，改由上方 .s-field 聚焦环统一呈现，避免刺眼黄色。
   注意：light-surface.css 的全局 input:focus 用 !important 设金色描边+光晕，此处以更高特异性 + !important 覆盖；
   并压制其他遗留 CSS 的 .nav-search:focus-within 金框。确保搜索框聚焦后不再出现任何黄色视觉元素。 */
.nav-search.nav-search:focus-within{border-color:transparent;box-shadow:none;background:transparent}
.nav-search .s-field input:focus,
.nav-search .s-field input:focus-visible{outline:none!important;border-color:transparent!important;box-shadow:none!important}
/* 抑制 Chrome 自动填充（autofill）的黄色背景高亮：沿用搜索框底色与文字色，并延迟底色回闪使其不可见 */
.nav-search .s-field input:-webkit-autofill,
.nav-search .s-field input:-webkit-autofill:hover,
.nav-search .s-field input:-webkit-autofill:focus,
.nav-search .s-field input:-webkit-autofill:active{
  -webkit-text-fill-color:#16203a;
  caret-color:#16203a;
  -webkit-box-shadow:0 0 0 100px rgba(255,255,255,.72) inset;
  box-shadow:0 0 0 100px rgba(255,255,255,.72) inset;
  transition:background-color .2s ease-in-out 0s;
}
.nav-search .s-field svg{width:15px;height:15px;color:rgba(13,23,48,.45);flex:none}
.nav-search .s-field input{flex:1;min-width:0;height:100%;background:none;border:none;outline:none;color:#16203a;font-size:13.5px}
.nav-search .s-field input::placeholder{color:rgba(13,23,48,.42)}
.nav-search .s-panel{position:absolute;top:calc(100% + 14px);right:0;width:300px;max-width:82vw;
  background:linear-gradient(180deg,#ffffff,#f7f9fc);
  border:1px solid rgba(13,23,48,.12);border-radius:14px;padding:10px;
  box-shadow:0 22px 50px -12px rgba(13,23,48,.28);
  opacity:0;visibility:hidden;transform:translateY(8px) scale(.98);transform-origin:top right;
  transition:opacity .25s var(--ease),transform .25s var(--ease),visibility .25s var(--ease);z-index:82}
.nav-search.open .s-panel{opacity:1;visibility:visible;transform:translateY(0) scale(1)}
.nav-search .s-results{max-height:300px;overflow:auto}
.nav-search .s-results a{display:block;padding:10px 12px;border-radius:9px;color:#3a445c;font-size:13.5px;text-decoration:none;border-left:2px solid transparent;transition:background .2s var(--ease),color .2s var(--ease),border-color .2s var(--ease)}
.nav-search .s-results a b{color:#0d1730;font-weight:600}
.nav-search .s-results a:hover,.nav-search .s-results a.active{background:linear-gradient(90deg,rgba(184,137,62,.14),rgba(184,137,62,.03));color:var(--gold-deep);border-left-color:var(--gold)}
.nav-search .s-results .s-sec{display:block;font-size:11px;color:#5a6478;margin-top:2px}
.nav-search .s-hint{padding:5px 12px;color:#5a6478;font-size:13px;white-space:nowrap;line-height:1.3}
.nav-search .s-foot{margin-top:6px;padding-top:8px;border-top:1px solid var(--navy-line);font-size:11.5px;color:#5a6478;text-align:center}
.menu-btn{display:none;flex-direction:column;gap:5px;background:none;border:none;cursor:pointer;padding:6px}
.menu-btn span{width:22px;height:2px;background:var(--ink-2);border-radius:2px;transition:.3s}
.menu-btn[aria-expanded="true"] span:nth-child(1){transform:translateY(7px) rotate(45deg)}
.menu-btn[aria-expanded="true"] span:nth-child(2){opacity:0}
.menu-btn[aria-expanded="true"] span:nth-child(3){transform:translateY(-7px) rotate(-45deg)}
.mobile-menu{position:fixed;inset:68px 0 auto 0;z-index:49;background:#f7f9fc;
  display:none;flex-direction:column;padding:14px 24px 26px;border-bottom:1px solid rgba(13,23,48,.08);
  box-shadow:0 22px 44px -20px rgba(13,23,48,.30)}
.mobile-menu a{padding:14px 6px;color:#2f3a54;border-bottom:1px solid rgba(13,23,48,.07);font-size:16px;text-decoration:none}
.mobile-menu .mm-cta{margin-top:14px;justify-content:center;color:#1a1304;border-bottom:none;
  background:linear-gradient(135deg,var(--gold),var(--gold-2));border-radius:10px;font-weight:700}

/* ---------- 二级下拉（与首页一致） ---------- */
.nav .has-menu{position:relative}
/* 悬停桥接：填补导航项与下拉间 12px 空隙，避免鼠标下移时 :hover 丢失导致二级菜单点不到 */
.nav .has-menu::after{content:"";position:absolute;left:0;right:0;top:100%;height:16px;z-index:79}
/* 锚点跳转时避开 sticky 导航遮挡 */
main [id],section[id]{scroll-margin-top:88px}
.nav .caret{display:inline-block;width:6px;height:6px;border-right:1.6px solid currentColor;border-bottom:1.6px solid currentColor;transform:rotate(45deg);margin-left:7px;margin-bottom:2px;opacity:.55;transition:transform .22s var(--ease),opacity .2s}
.nav .has-menu:hover .caret,.nav .has-menu.open .caret{transform:rotate(225deg);opacity:1;border-color:var(--gold-deep)}
.nav .dropdown{position:absolute;top:calc(100% + 12px);left:50%;transform:translateX(-50%) translateY(10px) scale(.985);min-width:0;width:fit-content;max-width:90vw;
  background:linear-gradient(180deg,#ffffff,#f7f9fc);
  -webkit-backdrop-filter:blur(18px) saturate(160%);backdrop-filter:blur(18px) saturate(160%);
  border:1px solid rgba(13,23,48,.12);border-radius:16px;
  box-shadow:0 26px 60px -16px rgba(13,23,48,.30);
  padding:8px;opacity:0;visibility:hidden;
  transition:opacity .26s var(--ease),transform .26s var(--ease),visibility .26s;z-index:80}
.nav .dropdown::before{display:none}
.nav .dropdown::after{content:"";position:absolute;inset:0;border-radius:16px;pointer-events:none;
  background:linear-gradient(115deg,transparent 32%,rgba(184,137,62,.10) 50%,transparent 68%);background-size:260% 100%;background-position:130% 0;opacity:0;transition:opacity .3s var(--ease)}
.nav .has-menu:hover .dropdown,.nav .has-menu.open .dropdown{opacity:1;visibility:visible;transform:translateX(-50%) translateY(0) scale(1)}
.nav .has-menu:hover .dropdown::after,.nav .has-menu.open .dropdown::after{opacity:1;animation:dpSheen 1.15s var(--ease) .08s}
@keyframes dpSheen{from{background-position:130% 0}to{background-position:-40% 0}}
.nav .dropdown .dp-list{display:flex;flex-direction:column;padding-top:2px;position:relative;z-index:2}
.nav .dropdown .dp-list a{display:block;padding:8px 14px;border-radius:9px;color:#3a445c;font-size:14px;font-weight:400;white-space:nowrap;
  border-left:2px solid transparent;opacity:0;transform:translateY(7px);
  transition:opacity .3s var(--ease),transform .3s var(--ease),background .22s var(--ease),color .22s var(--ease),border-color .22s var(--ease);text-decoration:none}
.nav .has-menu:hover .dp-list a,.nav .has-menu.open .dp-list a{opacity:1;transform:translateY(0)}
.nav .has-menu:hover .dp-list a:nth-child(1),.nav .has-menu.open .dp-list a:nth-child(1){transition-delay:.04s}
.nav .has-menu:hover .dp-list a:nth-child(2),.nav .has-menu.open .dp-list a:nth-child(2){transition-delay:.08s}
.nav .has-menu:hover .dp-list a:nth-child(3),.nav .has-menu.open .dp-list a:nth-child(3){transition-delay:.12s}
.nav .has-menu:hover .dp-list a:nth-child(4),.nav .has-menu.open .dp-list a:nth-child(4){transition-delay:.16s}
.nav .has-menu:hover .dp-list a:nth-child(5),.nav .has-menu.open .dp-list a:nth-child(5){transition-delay:.20s}
.nav .dropdown .dp-list a:hover{background:linear-gradient(90deg,rgba(184,137,62,.14),rgba(184,137,62,.03));color:#8a6428;border-left-color:var(--gold);transform:translateX(4px)}
@media (prefers-reduced-motion:reduce){
  .nav .dropdown{transform:translateX(-50%) translateY(0) scale(1)}
  .nav .dropdown .dp-list a{opacity:1;transform:none}
  .nav .dropdown::after{display:none}
  header.nav{transition:none}
  header.nav::after{transform:scaleX(1);opacity:1}
  header.nav::before{animation:none;opacity:.6}   /* 关闭动效、保留静态柔光，避免"突然变死板" */
}
/* 非首页下拉/搜索面板：保持完全不透明，确保浅色页内容下文字清晰可读
   （导航栏本身已与首页统一使用 nav.css 基础 header.nav 的浅色渐变玻璃背景） */
body:not([data-page="home"]) .nav .dropdown{
  background:linear-gradient(180deg,#ffffff,#f7f9fc);
  box-shadow:0 26px 60px -16px rgba(13,23,48,.34)}
body:not([data-page="home"]) .nav .dropdown .dp-list a{color:#2f3a54}
body:not([data-page="home"]) .nav-search .s-panel{
  background:#ffffff;
  box-shadow:0 22px 50px -12px rgba(13,23,48,.30)}
body:not([data-page="home"]) .nav-search .s-results a{color:#2f3a54}

/* 移动端：收起横向导航，显示汉堡按钮与抽屉；顶栏恢复 logo 左 / 汉堡右的常规对称布局
   断点与首页 platform.css 的 (max-width:980px) 对齐，确保全站响应式表现一致 */
@media (max-width:980px){
  .nav-inner{justify-content:space-between}
  .main,.nav-search{display:none}
  .nav-cta--bar{display:none}
  .menu-btn{display:flex}
  .mobile-menu.open{display:flex}
}