/* ============================================================
   ChemB2B - Header 导航 + Footer 样式 v3.0
   沉浸式导航 | 高级感页脚
   ============================================================ */

/* ---- 顶部导航栏 ---- */
.site-header {
  position: sticky; top: 0; z-index: 1000; height: var(--header-h);
  background: rgba(255,255,255,.92);
  backdrop-filter: blur(24px) saturate(180%);
  -webkit-backdrop-filter: blur(24px) saturate(180%);
  border-bottom: 1px solid rgba(226,232,240,.6);
  box-shadow: 0 1px 3px rgba(0,0,0,.03);
  transition: all var(--transition);
}
.site-header.scrolled {
  box-shadow: 0 4px 24px rgba(0,0,0,.08);
  border-bottom-color: transparent;
}

.header-inner {
  max-width: var(--max-width); margin: 0 auto; padding: 0 24px;
  display: flex; align-items: center; justify-content: space-between;
  height: 100%; gap: 28px;
}

/* Logo */
.logo { display: flex; align-items: center; gap: 10px; flex-shrink: 0; }
.logo-icon svg { display: block; }
.logo-text { 
  font-size: 1.5rem; font-weight: 900; color: var(--primary-dark); letter-spacing: -0.5px;
  background: linear-gradient(135deg, var(--primary-dark), var(--primary));
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}
.logo-text .accent { 
  background: linear-gradient(135deg, var(--accent), var(--accent-light));
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; 
}
.logo-sub { 
  font-size: .62rem; color: var(--text-muted); display: block; line-height: 1; 
  margin-top: 2px; letter-spacing: 0.5px;
}

/* Nav */
.main-nav { display: flex; align-items: center; gap: 2px; }
.nav-link {
  padding: 8px 15px; border-radius: var(--radius); font-size: .91rem; font-weight: 500;
  color: var(--text-secondary); transition: all var(--transition); white-space: nowrap;
  position: relative;
}
.nav-link::after {
  content: ''; position: absolute; bottom: -2px; left: 50%; transform: translateX(-50%);
  width: 0; height: 2px; background: var(--primary-gradient); border-radius: 2px;
  transition: width var(--transition);
}
.nav-link:hover { color: var(--primary); background: var(--primary-bg); }
.nav-link:hover::after { width: 60%; }
.nav-link.active { color: var(--primary); font-weight: 600; background: var(--primary-bg); }
.nav-link.active::after { width: 60%; }
.nav-link .nav-badge {
  position: absolute; top: -2px; right: -4px; min-width: 16px; height: 16px;
  padding: 0 5px; border-radius: 8px; background: var(--danger); color: #fff;
  font-size: .62rem; font-weight: 700; display: flex; align-items: center; justify-content: center;
  box-shadow: 0 2px 4px rgba(239,68,68,.3);
}

/* Header Actions */
.header-actions { display: flex; align-items: center; gap: 12px; flex-shrink: 0; }
.header-actions .btn { font-size: .88rem; padding: 8px 18px; border-radius: var(--radius); }

/* 通知铃铛 */
.notify-btn {
  width: 38px; height: 38px; border-radius: var(--radius); position: relative;
  background: var(--bg); color: var(--text-secondary); font-size: 1.1rem;
  display: flex; align-items: center; justify-content: center; transition: all var(--transition);
}
.notify-btn:hover { background: var(--primary-bg); color: var(--primary); }
.notify-dot {
  position: absolute; top: 6px; right: 6px; width: 8px; height: 8px;
  border-radius: 50%; background: var(--danger); border: 2px solid var(--white);
  box-shadow: 0 0 6px rgba(239,68,68,.4);
}

/* User Menu */
.user-menu { position: relative; display: flex; align-items: center; gap: 8px; cursor: pointer; padding: 5px 10px; border-radius: var(--radius); transition: all var(--transition); }
.user-menu:hover { background: var(--bg); }
.user-avatar {
  width: 38px; height: 38px; border-radius: 50%; 
  background: var(--primary-gradient); display: flex; align-items: center; justify-content: center;
  color: #fff; font-weight: 800; font-size: .88rem; box-shadow: 0 2px 8px rgba(3,105,161,.3);
}
.user-name { 
  font-size: .88rem; font-weight: 600; color: var(--text); 
  max-width: 100px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.user-dropdown {
  position: absolute; top: 100%; right: 0; margin-top: 10px;
  background: var(--white); border-radius: var(--radius-lg); box-shadow: var(--shadow-xl);
  border: 1px solid var(--border-light); min-width: 200px; padding: 8px 0;
  opacity: 0; visibility: hidden; transform: translateY(-10px);
  transition: all var(--transition); z-index: 100;
}
.user-menu:hover .user-dropdown { opacity: 1; visibility: visible; transform: translateY(0); }
.user-dropdown .dropdown-header {
  padding: 12px 18px; border-bottom: 1px solid var(--border-light);
  font-weight: 600; font-size: .85rem; color: var(--text);
}
.user-dropdown a {
  display: flex; align-items: center; gap: 10px; padding: 11px 18px; font-size: .88rem; 
  color: var(--text-secondary); transition: all var(--transition);
}
.user-dropdown a:hover { background: var(--primary-bg); color: var(--primary); }
.user-dropdown .dropdown-divider { height: 6px; background: var(--bg); }

/* Mobile Menu Btn */
.mobile-menu-btn {
  display: none; flex-direction: column; gap: 5px; background: none; padding: 8px;
  width: 38px; height: 38px; align-items: center; justify-content: center; border-radius: var(--radius-sm);
}
.mobile-menu-btn:hover { background: var(--bg); }
.mobile-menu-btn span {
  display: block; width: 22px; height: 2.5px; background: var(--text);
  border-radius: 2px; transition: all var(--transition); transform-origin: center;
}
.mobile-menu-btn.active span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
.mobile-menu-btn.active span:nth-child(2) { opacity: 0; width: 0; }
.mobile-menu-btn.active span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

.mobile-overlay {
  display: none; position: fixed; inset: 0; background: rgba(15,23,42,.5);
  backdrop-filter: blur(4px); z-index: 999; opacity: 0; transition: opacity var(--transition);
}
.mobile-overlay.active { opacity: 1; }


/* ============================================================
   页脚 Footer v3.0 - 高级感企业级
   ============================================================ */
.site-footer {
  background: linear-gradient(180deg, #0f172a 0%, #020617 100%);
  color: #94a3b8; padding: 0; margin-top: 80px; position: relative; z-index: 1;
}
.site-footer::before {
  content: ''; position: absolute; top: 0; left: 0; right: 0; height: 1px;
  background: linear-gradient(90deg, transparent, rgba(6,182,212,.3), transparent);
}

.footer-top {
  max-width: var(--max-width); margin: 0 auto; padding: 56px 24px 0;
  display: grid; grid-template-columns: 2fr 1fr 1fr 1fr 1fr; gap: 40px;
}

.footer-brand p { 
  margin: 14px 0 18px; font-size: .88rem; line-height: 1.75; 
  color: #64748b; max-width: 300px;
}
.footer-logo { 
  font-size: 1.5rem; font-weight: 900; color: #fff; display: block; margin-bottom: 4px; 
  letter-spacing: -0.5px;
}
.footer-logo .accent { 
  background: linear-gradient(135deg, var(--accent), var(--accent-light));
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}
.footer-logo-sub { font-size: .7rem; color: #475569; letter-spacing: 0.5px; }

.footer-contact { display: flex; flex-direction: column; gap: 8px; }
.footer-contact .contact-row {
  display: flex; align-items: center; gap: 10px; font-size: .85rem; color: #64748b;
}
.footer-contact .contact-icon {
  width: 32px; height: 32px; border-radius: var(--radius-sm); 
  background: rgba(255,255,255,.05); display: flex; align-items: center; justify-content: center;
  font-size: .9rem; flex-shrink: 0;
}

.footer-col h4 { 
  color: #e2e8f0; font-size: .95rem; margin-bottom: 18px; font-weight: 700;
  position: relative; padding-bottom: 12px;
}
.footer-col h4::after {
  content: ''; position: absolute; bottom: 0; left: 0;
  width: 28px; height: 2.5px; background: var(--accent-gradient); border-radius: 2px;
}
.footer-col a { 
  display: block; color: #64748b; font-size: .85rem; padding: 7px 0; 
  transition: all var(--transition);
}
.footer-col a:hover { color: var(--accent); padding-left: 4px; }

.footer-social { display: flex; gap: 10px; margin-top: 20px; }
.footer-social a {
  width: 38px; height: 38px; border-radius: var(--radius); 
  background: rgba(255,255,255,.05); color: #64748b;
  display: flex; align-items: center; justify-content: center; font-size: 1rem;
  transition: all var(--transition);
}
.footer-social a:hover { background: var(--accent); color: #fff; }

.footer-bottom {
  margin-top: 48px; border-top: 1px solid rgba(255,255,255,.06);
}
.footer-bottom-inner {
  max-width: var(--max-width); margin: 0 auto; padding: 24px;
  display: flex; align-items: center; justify-content: space-between;
  flex-wrap: wrap; gap: 12px; font-size: .82rem; color: #475569;
}
.footer-bottom-links { display: flex; gap: 20px; flex-wrap: wrap; }
.footer-bottom-links a { color: #475569; transition: color var(--transition); }
.footer-bottom-links a:hover { color: var(--accent); }

.footer-cert { display: flex; gap: 16px; flex-wrap: wrap; margin-top: 16px; }
.footer-cert span {
  padding: 4px 10px; border-radius: 4px; font-size: .72rem; 
  background: rgba(255,255,255,.04); color: #475569;
}


/* ============================================================
   响应式
   ============================================================ */
@media (max-width: 1024px) {
  .main-nav { gap: 0; }
  .nav-link { padding: 8px 10px; font-size: .84rem; }
  .footer-top { gap: 28px; }
}
@media (max-width: 768px) {
  .mobile-menu-btn { display: flex; }
  .main-nav {
    position: fixed; top: var(--header-h); left: 0; right: 0; bottom: 0;
    background: var(--white); flex-direction: column; align-items: stretch;
    padding: 12px; gap: 0; transform: translateX(-100%);
    transition: transform var(--transition-slow); z-index: 1000;
    overflow-y: auto; box-shadow: var(--shadow-xl);
  }
  .main-nav.active { transform: translateX(0); }
  .nav-link {
    padding: 15px 16px; font-size: .95rem; border-radius: var(--radius);
    border-bottom: 1px solid var(--border-light);
  }
  .nav-link::after { display: none; }
  .nav-link.active { border-radius: var(--radius); }
  .mobile-overlay.active { display: block; }
  .header-actions .btn { padding: 6px 14px; font-size: .82rem; }

  .footer-top { grid-template-columns: 1fr 1fr; gap: 32px; }
  .footer-brand { grid-column: 1 / -1; }
  .footer-bottom-inner { flex-direction: column; text-align: center; }
}
@media (max-width: 480px) {
  .footer-top { grid-template-columns: 1fr; text-align: center; }
  .footer-col h4::after { left: 50%; transform: translateX(-50%); }
  .footer-brand p { margin-left: auto; margin-right: auto; }
  .footer-contact { align-items: center; }
  .footer-social { justify-content: center; }
  .site-footer { padding: 40px 0 0; }
  .footer-bottom-links { justify-content: center; }
}