/* ==========================================================
   header.css - 头部样式
   所有样式作用于 .site-header 内，作用域隔离
   ========================================================== */

/* ---------- 顶部导航 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.82);
  -webkit-backdrop-filter: blur(18px);
  backdrop-filter: blur(18px);
  border-bottom: 1px solid var(--line);
}

.site-header .header-inner{
  display: flex;
  align-items: center;
  gap: 32px;
  height: 60px;
}

.site-header .main-nav{
  display: flex;
  align-items: center;
  gap: 4px;
  flex: 1 1 auto;
}
.site-header .main-nav-head{ display: none; }

.site-header .nav-link, .site-header .main-nav > a, .site-header .main-nav > .nav-item > a{
  padding: 6px 14px;
  font-size: 14px;
  color: var(--text-2);
  border-radius: 999px;
  transition: color 0.2s, background 0.2s;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  white-space: nowrap;
  flex-shrink: 0;
}

.site-header .nav-link:hover, .site-header .main-nav > a:hover, .site-header .main-nav > .nav-item > a:hover{ color: var(--text); background: rgba(0, 0, 0, 0.04); }
.site-header .nav-link.active, .site-header .main-nav > a.active{ color: var(--blue); font-weight: 600; }
.site-header .main-nav .nav-arrow{ width: 12px; height: 12px; opacity: .5; }
.site-header .main-nav .nav-item{ position: relative; }
.site-header .main-nav .nav-submenu{
  position: absolute; top: 100%; left: 0; min-width: 180px;
  background: #fff; border: 1px solid var(--line); border-radius: 12px;
  box-shadow: 0 12px 32px rgba(0,0,0,.1); padding: 6px; z-index: 50;
  opacity: 0; visibility: hidden; transform: translateY(-6px); transition: all .2s;
}
.site-header .main-nav .nav-item:hover > .nav-submenu{ opacity: 1; visibility: visible; transform: translateY(0); }
.site-header .main-nav .nav-submenu a{ display: block; padding: 8px 12px; font-size:14px; border-radius: 8px; }
.site-header .main-nav .nav-submenu a:hover{ background: var(--blue-light); color: var(--blue); }

.site-header .header-actions{
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}

.site-header .search-form{
  display: flex;
  align-items: center;
  gap: 8px;
  width: 260px;
  height: 34px;
  padding: 0 14px;
  background: rgba(0, 0, 0, 0.05);
  border-radius: 999px;
  transition: background 0.2s, box-shadow 0.2s;
}

.site-header .search-form:focus-within{
  background: #fff;
  box-shadow: 0 0 0 2px var(--blue);
}

.site-header .search-icon{ color: var(--text-3); flex-shrink: 0; }

.site-header .search-input{
  flex: 1 1 auto;
  border: none;
  outline: none;
  background: transparent;
  font-size:14px;
  font-family:inherit;
  color: var(--text);
}
.site-header .search-input::placeholder{ color: var(--text-3); font-family:inherit; }

.site-header .search-toggle{
  display: none;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  border: none;
  background: rgba(0,0,0,.05);
  color: var(--text-2);
  border-radius: 999px;
  cursor: pointer;
  transition: background .2s, color .2s;
  flex-shrink: 0;
}
.site-header .search-toggle:hover{ background: var(--blue); color: #fff; }

.site-header .header-search-panel{
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  background: #fff;
  box-shadow: 0 6px 20px rgba(0,0,0,.08);
  padding: 14px 0;
  z-index: 999;
  animation: searchPanelSlide .2s ease;
}
@keyframes searchPanelSlide {
  from { opacity: 0; transform: translateY(-8px); }
  to { opacity: 1; transform: translateY(0); }
}
.site-header .header-search-panel.active{ display: block; }
.site-header .header-search-panel-inner{
  display: flex;
  align-items: center;
  gap: 12px;
}
.site-header .header-search-panel-form{
  display: flex;
  align-items: center;
  gap: 10px;
  flex: 1;
  height: 42px;
  padding: 0 16px;
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: 999px;
  transition: border-color .2s, box-shadow .2s;
}
.site-header .header-search-panel-form:focus-within{
  border-color: var(--blue);
  box-shadow: 0 0 0 3px rgba(24,144,255,.12);
  background: #fff;
}
.site-header .header-search-panel-icon{ color: var(--text-3); flex-shrink: 0; }
.site-header .header-search-panel-input{
  flex: 1;
  border: none;
  outline: none;
  background: transparent;
  font-size: 15px;
  font-family: inherit;
  color: var(--text);
}
.site-header .header-search-panel-input::placeholder{ color: var(--text-3); font-family: inherit; }
.site-header .header-search-panel-btn{
  border: none;
  height: 32px;
  padding: 0 20px;
  background: var(--blue);
  color: #fff;
  font-size: 14px;
  font-weight: 500;
  border-radius: 999px;
  cursor: pointer;
  transition: background .2s;
  flex-shrink: 0;
}
.site-header .header-search-panel-btn:hover{ background: #096dd9; }
.site-header .header-search-panel-close{
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border: none;
  background: transparent;
  color: var(--text-3);
  border-radius: 50%;
  cursor: pointer;
  transition: background .2s, color .2s;
  flex-shrink: 0;
}
.site-header .header-search-panel-close:hover{ background: var(--bg); color: var(--text); }

.site-header .btn-login{
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 34px;
  padding: 0 18px;
  background: var(--blue);
  color: #fff;
  font-size:14px;
  font-weight: 500;
  border-radius: 999px;
  transition: background 0.2s, transform 0.1s;
}

.site-header .btn-login:hover{ background: var(--blue-dark); }
.site-header .btn-login:active{ transform: scale(0.97); }

.site-header .nav-toggle{
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  padding: 0 9px;
  border: none;
  background: transparent;
}

.site-header .nav-toggle span{
  display: block;
  height: 2px;
  width: 100%;
  background: var(--text);
  border-radius: 2px;
  transition: transform 0.25s, opacity 0.25s;
}

.site-header .nav-toggle.open span:nth-child(1){ transform: translateY(7px) rotate(45deg); }
.site-header .nav-toggle.open span:nth-child(2){ opacity: 0; }
.site-header .nav-toggle.open span:nth-child(3){ transform: translateY(-7px) rotate(-45deg); }

@media (max-width: 1240px) {
    .site-header .search-form{ display: none; }
    .site-header .search-toggle{ display: flex; }
}

@media (max-width: 900px) {
    .site-header {
      -webkit-backdrop-filter: none;
      backdrop-filter: none;
      background: #fff;
    }
    .site-header .header-inner{
      flex-wrap: wrap;
      height: auto;
      padding: 10px 0 12px;
      gap: 10px 16px;
      position: relative;
    }
    .site-header .nav-toggle{ display: flex; order: 2; margin-left: auto; }
    .site-header .header-actions{
      order: 3;
      width: 100%;
      justify-content: center;
      gap: 10px;
      padding-top: 8px;
      border-top: 1px solid var(--line);
    }
    .site-header .nav-overlay{
      position: fixed;
      inset: 0;
      background: rgba(0, 0, 0, 0.5);
      z-index: 200;
      cursor: pointer;
      animation: fadeIn .2s ease;
    }
    @keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }
    .site-header .main-nav{
      position: fixed;
      top: 0;
      right: 0;
      bottom: 0;
      width: 300px;
      max-width: 85vw;
      flex-direction: column;
      align-items: stretch;
      gap: 0;
      background: #fff;
      box-shadow: -8px 0 40px rgba(0, 0, 0, 0.18);
      padding: 0;
      display: none;
      z-index: 201;
      max-height: 100vh;
      overflow-y: auto;
      -webkit-overflow-scrolling: touch;
      border-radius: 0;
    }
    .site-header .main-nav::-webkit-scrollbar{ width: 4px; }
    .site-header .main-nav::-webkit-scrollbar-thumb{ background: #ddd; border-radius: 4px; }
    .site-header .main-nav-head{
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 16px 18px;
      background: #1a1a2e;
      color: #fff;
      flex-shrink: 0;
    }
    .site-header .main-nav-title{
      font-size: 15px;
      font-weight: 600;
      color: #fff;
    }
    .site-header .main-nav-close{
      width: 30px;
      height: 30px;
      display: flex;
      align-items: center;
      justify-content: center;
      border: none;
      background: rgba(255,255,255,0.12);
      border-radius: 50%;
      color: #fff;
      cursor: pointer;
      transition: background .15s, transform .15s;
    }
    .site-header .main-nav-close:hover{
      background: rgba(255,255,255,0.25);
      transform: rotate(90deg);
    }
    .site-header .main-nav.open{
      display: flex;
      animation: menuSlideIn .26s cubic-bezier(.2,.8,.2,1);
    }
    @keyframes menuSlideIn {
      from { opacity: 0; transform: translateX(100%); }
      to { opacity: 1; transform: translateX(0); }
    }
    .site-header .nav-link, .site-header .main-nav > a, .site-header .main-nav > .nav-item > a{
      padding: 14px 18px;
      font-size: 15px;
      font-weight: 500;
      border-radius: 0;
      color: var(--text);
      display: flex;
      align-items: center;
      gap: 10px;
      position: relative;
      transition: background .15s, color .15s;
      border-bottom: 1px solid #f0f0f0;
      white-space: nowrap;
      flex-shrink: 0;
    }
    .site-header .nav-link:hover, .site-header .main-nav > a:hover, .site-header .main-nav > .nav-item > a:hover{
      background: #f5f7fa;
      color: var(--blue);
    }
    .site-header .nav-link.active, .site-header .main-nav > a.active{
      color: var(--blue);
      background: #f0f7ff;
      font-weight: 600;
      border-left: 3px solid var(--blue);
      padding-left: 15px;
    }
    .site-header .main-nav .nav-item{ border-radius: 0; }
    .site-header .main-nav .nav-arrow{
      margin-left: auto;
      width: 14px;
      height: 14px;
      opacity: .5;
      transition: transform .2s;
      fill: none;
      stroke: currentColor;
      stroke-width: 2;
      stroke-linecap: round;
      stroke-linejoin: round;
    }
    .site-header .main-nav .nav-item:hover .nav-arrow{ transform: rotate(180deg); opacity: .8; }
    .site-header .main-nav .nav-submenu{
      position: static;
      opacity: 1;
      visibility: visible;
      transform: none;
      box-shadow: none;
      padding: 0;
      margin: 0;
      background: #fafbfc;
      border-radius: 0;
      display: flex;
      flex-direction: column;
      gap: 0;
      border-bottom: 1px solid #f0f0f0;
    }
    .site-header .main-nav .nav-submenu a{
      padding: 10px 18px 10px 34px;
      font-size: 14px;
      color: var(--text-2);
      border-radius: 0;
      transition: background .15s, color .15s;
      border-bottom: 1px solid #f5f5f5;
      display: block;
    }
    .site-header .main-nav .nav-submenu a:last-child{ border-bottom: none; }
    .site-header .main-nav .nav-submenu a:hover{
      background: #f0f7ff;
      color: var(--blue);
    }
}

@media (max-width: 640px) {
    .site-header .header-inner{ gap: 8px 12px; padding: 8px 0 10px; }
    .site-header .header-actions{ gap: 8px; padding-top: 6px; }
    .site-header .search-form{ display: none; }
    .site-header .btn-login{ height: 32px; padding: 0 10px; font-size: 13px; }
}