/* ========== 全站统一导航（含悬停下拉、移动端侧栏） ========== */
/* 深色覆盖见 dark.css（.drop-menu / #nav-menu / #themeToggle 已全局适配） */

nav#navbar{position:fixed;top:0;left:0;right:0;z-index:1000;padding:20px 5%;background:rgba(255,255,255,.7);backdrop-filter:blur(20px);-webkit-backdrop-filter:blur(20px);transition:all .4s cubic-bezier(.4,0,.2,1);}
.nav-container{max-width:1440px;margin:0 auto;display:flex;justify-content:space-between;align-items:center;}
.nav-left{display:flex;align-items:center;}
.nav-logo{font-size:20px;font-weight:600;color:#1d1d1f;text-decoration:none;letter-spacing:-.5px;transition:all .3s;}
.nav-logo:hover{color:#06c;}
.nav-right{display:flex;align-items:center;gap:26px;}
#nav-menu{list-style:none;display:flex;align-items:center;gap:34px;margin:0;padding:0;}
#nav-menu > li > a{text-decoration:none;color:#1d1d1f;font-size:15px;letter-spacing:.3px;padding:8px 0;position:relative;transition:all .3s;}
#nav-menu > li > a::after{content:'';position:absolute;bottom:0;left:50%;width:0;height:1px;background:#1d1d1f;transition:all .3s;transform:translateX(-50%);}
#nav-menu > li > a:hover{color:#06c;}
#nav-menu > li > a:hover::after{width:100%;}

/* 下拉菜单（推送区） */
.has-drop{position:relative;}
.has-drop::after{content:'';position:absolute;top:100%;left:0;right:0;height:14px;}
.drop-toggle{display:inline-flex;align-items:center;gap:4px;}
.drop-toggle .arr{font-size:11px;color:#8a8a8f;transition:transform .25s ease;}
.has-drop:hover .drop-toggle .arr{transform:rotate(180deg);}
.drop-menu{visibility:hidden;opacity:0;position:absolute;top:calc(100% + 12px);left:0;min-width:160px;background:#fff;border-radius:14px;box-shadow:0 12px 32px rgba(0,0,0,.14);padding:8px;list-style:none;display:block;transform:translateY(10px);transition:all .25s ease;z-index:1200;margin:0;}
.has-drop:hover .drop-menu,.has-drop:focus-within .drop-menu{visibility:visible;opacity:1;transform:translateY(0);}
#navbar .drop-menu li{width:100%;}
#navbar .drop-menu a{display:block;padding:10px 16px;font-size:14px;color:#1d1d1f;text-decoration:none;border-radius:9px;white-space:nowrap;transition:all .2s;}
#navbar .drop-menu a::after{display:none;}
#navbar .drop-menu a:hover{background:#f2f5fa;color:#06c;}

/* 右侧登录态区 */
.nav-auth{display:flex;align-items:center;gap:12px;}
.user-chip{display:flex;align-items:center;gap:8px;font-size:14px;font-weight:500;color:#1d1d1f;text-decoration:none;padding:4px 14px 4px 5px;border-radius:20px;background:#f2f2f5;transition:all .3s;}
.user-chip:hover{background:#e8f2ff;color:#06c;}
.nav-avatar{width:28px;height:28px;border-radius:50%;object-fit:cover;}
.auth-link{background:none;border:1px solid rgba(0,102,204,.35);color:#06c;font-size:14px;font-weight:500;cursor:pointer;padding:7px 16px;border-radius:20px;text-decoration:none;transition:all .3s;}
.auth-link:hover{background:#06c;color:#fff;}
.hamburger{display:none;background:none;border:none;font-size:24px;color:#1d1d1f;cursor:pointer;z-index:1001;padding:4px 8px;}
.mobile-only{display:none;}

@media (max-width:768px){
  #nav-menu{gap:20px;}
  #nav-menu > li > a{font-size:14px;}
  #navbar .drop-menu a{font-size:13px;}
  .nav-logo{font-size:18px;}
}
@media (max-width:480px){
  .hamburger{display:block;}
  .nav-auth .nav-username,.nav-auth .auth-link{display:none;}
  .mobile-only{display:flex;flex-wrap:wrap;gap:26px;justify-content:center;}
  #nav-menu{display:none;position:fixed;top:0;right:0;width:240px;height:100vh;background:rgba(255,255,255,.96);backdrop-filter:blur(20px);flex-direction:column;justify-content:center;gap:24px;padding:30px 24px;box-shadow:-2px 0 10px rgba(0,0,0,.1);z-index:1000;}
  #nav-menu.active{display:flex;}
  #nav-menu > li > a{font-size:16px;}
  .has-drop::after{display:none;}
  .drop-menu{visibility:visible;opacity:1;transform:none;position:static;background:transparent;box-shadow:none;border-radius:0;padding:6px 0 0 18px;min-width:0;margin:0;}
  #navbar .drop-menu a{padding:7px 10px;color:#6e6e73;font-size:14px;}
  #navbar .drop-menu a:hover{background:transparent;color:#06c;}
}