/* =========================================================================
   SLai · 导航栏精修 v7-nav
   -------------------------------------------------------------------------
   问题（对照截图）：
     右上角"简 / 繁 / EN"和"获取 SLai"发虚、对比度低。
   根因：
     1) .nav 用了 backdrop-filter: blur(14px)，把背后的极光层也"模糊化"了，
        文字边缘被半透明背景吃掉
     2) 导航背景 rgba(7,4,14,.82) 不够实，极光透上来削弱对比
     3) 语言按钮字号 11px、颜色偏灰，本身就不够清晰
   修法：
     · 去掉 backdrop-filter，改用更实的深色底 + 底部渐变
     · 文字提到 13px，纯白/接近纯白
     · 语言切换改成实心胶囊，选中态高亮
     · CTA 按钮加实底 + 边框，边界清晰
     · 所有交互元素加 8px 圆角统一
   ========================================================================= */

/* ---------- 1. 导航容器 ---------- */
.nav{
  position:sticky;
  top:0;
  z-index:100;
  display:flex;
  align-items:center;
  gap:32px;
  padding:14px 0;
  background:rgba(9,5,16,.96);          /* 更实，几乎不透 */
  border-bottom:1px solid rgba(168,85,247,.18);
  backdrop-filter:none;                  /* 关键：去掉模糊 */
  -webkit-backdrop-filter:none;
}
.nav.is-stuck{
  background:rgba(9,5,16,.99);
  border-bottom-color:rgba(192,132,252,.34);
  box-shadow:0 1px 0 rgba(255,255,255,.04) inset, 0 10px 30px -20px rgba(0,0,0,.9);
  padding-top:10px;
  padding-bottom:10px;
}

/* 导航内部容器对齐主内容 */
.nav > .brand,
.nav > .nav-links,
.nav > .nav-right{
  position:relative;
  z-index:2;
}

/* ---------- 2. 品牌 ---------- */
.nav .brand{
  gap:11px;
  flex:0 0 auto;
  text-decoration:none;
}
.nav .brand-mark{
  width:34px;height:34px;
  border-radius:9px;
  border:1px solid rgba(168,85,247,.4);
  background:linear-gradient(160deg,rgba(168,85,247,.28),rgba(124,58,237,.12));
  color:#E9D5FF;
  font-size:15px;
  font-weight:700;
  box-shadow:0 0 16px -6px rgba(168,85,247,.8);
}
.nav .brand-text{
  font-size:16px;
  font-weight:700;
  letter-spacing:.02em;
  color:#FFFFFF;                        /* 纯白 */
  line-height:1.1;
}
.nav .brand-text em{
  display:block;
  margin-top:2px;
  font-family:var(--mono);
  font-size:8.5px;
  font-style:normal;
  letter-spacing:.24em;
  color:rgba(246,243,252,.42);          /* 副标压暗，主标更突出 */
  text-transform:uppercase;
}

/* ---------- 3. 主导航链接 ---------- */
.nav .nav-links{
  display:flex;
  align-items:center;
  gap:4px;
  margin-left:auto;
  margin-right:auto;
}
.nav .nav-links a{
  position:relative;
  padding:8px 14px;
  border-radius:8px;
  font-size:13.5px;
  font-weight:500;
  color:rgba(246,243,252,.72);          /* 从 .5 提到 .72 */
  transition:color .18s ease, background .18s ease;
  text-decoration:none;
}
.nav .nav-links a:hover{
  color:#FFFFFF;
  background:rgba(168,85,247,.12);
}
/* 悬停下划线 */
.nav .nav-links a::after{
  content:"";
  position:absolute;
  left:14px;right:14px;bottom:3px;
  height:1.5px;
  border-radius:2px;
  background:linear-gradient(90deg,#C084FC,#67E8F9);
  transform:scaleX(0);
  transform-origin:left;
  transition:transform .22s cubic-bezier(.22,.61,.36,1);
}
.nav .nav-links a:hover::after{transform:scaleX(1)}

/* ---------- 4. 右侧操作区 ---------- */
.nav .nav-right{
  display:flex;
  align-items:center;
  gap:10px;
  flex:0 0 auto;
}

/* 语言切换：实心胶囊 */
.nav .lang{
  display:inline-flex;
  align-items:center;
  gap:2px;
  padding:3px;
  border:1px solid rgba(168,85,247,.28);
  border-radius:9px;
  background:rgba(20,13,34,.9);          /* 实底，不透 */
}
.nav .lang-btn{
  min-width:30px;
  height:26px;
  padding:0 8px;
  border:0;
  border-radius:6px;
  background:transparent;
  color:rgba(246,243,252,.72);
  font-size:12.5px;                      /* 从 11 提到 12.5 */
  font-weight:600;
  font-family:var(--mono);
  letter-spacing:.02em;
  cursor:pointer;
  transition:background .16s ease, color .16s ease;
  line-height:1;
}
.nav .lang-btn:hover{
  color:#FFFFFF;
  background:rgba(168,85,247,.18);
}
.nav .lang-btn.is-active,
.nav .lang-btn[aria-pressed="true"]{
  background:linear-gradient(160deg,rgba(192,132,252,.9),rgba(124,58,237,.85));
  color:#FFFFFF;
  box-shadow:0 2px 8px -2px rgba(124,58,237,.9);
}

/* CTA 按钮：实底 + 清晰边框 */
.nav .nav-right .btn{
  height:36px;
  padding:0 18px;
  display:inline-flex;
  align-items:center;
  justify-content:center;
  border-radius:9px;
  font-size:13.5px;
  font-weight:600;
  letter-spacing:.01em;
  white-space:nowrap;
  text-decoration:none;
  transition:transform .16s ease, background .18s ease, border-color .18s ease, box-shadow .18s ease;
}
.nav .nav-right .btn.btn-ghost{
  border:1px solid rgba(168,85,247,.42);
  background:rgba(124,58,237,.16);
  color:#F6F3FC;
}
.nav .nav-right .btn.btn-ghost:hover{
  border-color:rgba(216,180,254,.7);
  background:rgba(168,85,247,.26);
  color:#FFFFFF;
  transform:translateY(-1px);
}

/* ---------- 5. 高 DPI 下更锐利 ---------- */
.nav *{
  -webkit-font-smoothing:antialiased;
  -moz-osx-font-smoothing:grayscale;
  text-rendering:optimizeLegibility;
}
.nav .nav-links a,
.nav .lang-btn,
.nav .nav-right .btn{
  will-change:auto;      /* 不提前提升图层，避免栅格化发虚 */
}

/* ---------- 6. 窄屏 ---------- */
@media(max-width:1000px){
  .nav{gap:16px}
  .nav .nav-links{gap:0}
  .nav .nav-links a{padding:7px 9px;font-size:12.5px}
}
@media(max-width:760px){
  .nav{padding:10px 0}
  .nav .nav-links{display:none}          /* 手机端收起主导航 */
  .nav .nav-right{margin-left:auto}
  .nav .brand-text em{display:none}
}