/* ── 桌面端顶部导航栏 ── */
.top-nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-height);
  background: var(--nav-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--nav-border);
  z-index: 100;
  transition: background var(--transition-fast);
}
.nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  gap: 2rem;
}
.nav-brand {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--color-brand);
  text-decoration: none;
  white-space: nowrap;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 6px;
}
.nav-brand:hover { opacity: 0.85; }
.nav-links {
  display: flex;
  gap: 2rem;
  margin: 0 auto;
}
.nav-link {
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--text-secondary);
  text-decoration: none;
  padding: 0 2px 4px;
  position: relative;
  cursor: pointer;
  transition: color var(--transition-fast);
  white-space: nowrap;
}
.nav-link:hover { color: var(--color-brand); }
.nav-link.active {
  color: var(--color-brand);
  font-weight: 600;
}
.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: -2px; left: 0;
  width: 100%; height: 2px;
  background: var(--color-brand);
  transform: scaleX(1);
  transition: transform var(--transition-fast);
}
.nav-link::after {
  content: '';
  position: absolute;
  bottom: -2px; left: 0;
  width: 100%; height: 2px;
  background: var(--color-brand);
  transform: scaleX(0);
  transition: transform var(--transition-fast);
}
.nav-link:hover::after { transform: scaleX(1); }
.nav-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-left: auto;
}
.theme-btn {
  width: 32px; height: 32px;
  border-radius: 50%;
  border: none;
  background: transparent;
  font-size: 1rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
  transition: background var(--transition-fast);
}
.theme-btn:hover { background: rgba(212, 165, 116, 0.1); }
.nav-team-link {
  font-size: 0.875rem;
  color: var(--text-secondary);
  text-decoration: none;
  cursor: pointer;
  font-weight: 500;
  transition: color var(--transition-fast);
}
.nav-team-link:hover { color: var(--color-brand); }

/* ── 移动端底部标签栏 ── */
.bottom-nav {
  display: none;
  position: fixed;
  bottom: 0; left: 0; right: 0;
  height: 64px;
  background: var(--bg-card);
  border-top: 0.5px solid var(--border-card);
  z-index: 100;
  padding-bottom: env(safe-area-inset-bottom);
  transition: background var(--transition-slow);
}
.bottom-nav-inner {
  display: flex;
  height: 100%;
}
.nav-tab {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
  cursor: pointer;
  border: none;
  background: transparent;
  color: var(--text-tertiary);
  transition: color var(--transition-fast), transform var(--transition-fast);
  -webkit-tap-highlight-color: transparent;
  min-height: 44px;
}
.nav-tab .tab-icon {
  width: 24px; height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  transition: transform var(--transition-fast);
}
.nav-tab .tab-label {
  font-size: 0.6875rem;
  font-weight: 500;
  transition: color var(--transition-fast);
}
.nav-tab.active {
  color: var(--color-brand);
}
.nav-tab.active .tab-label {
  font-weight: 600;
  color: var(--color-brand);
}
.nav-tab.active .tab-icon {
  transform: translateY(-2px) scale(1.1);
}
.nav-tab:active .tab-icon {
  transform: scale(0.95);
}

/* ── 移动端顶部条（默认隐藏，仅 ≤768px 显示）── */
.mobile-top-bar {
  display: none;
}

/* ── 响应式切换 ── */
@media (max-width: 768px) {
  body { --bottom-nav-height: 64px; }
  .top-nav { display: none; }
  .bottom-nav { display: block; }

  /* 移动端紧凑顶部条：logo + 主题 */
  .mobile-top-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: fixed;
    top: 0; left: 0; right: 0;
    height: 44px;
    padding: 0 16px;
    padding-top: env(safe-area-inset-top);
    background: var(--nav-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 0.5px solid var(--border-card);
    z-index: 101;
    transition: background var(--transition-fast);
  }
  .mobile-top-bar .mobile-brand {
    font-size: 0.9375rem;
    font-weight: 700;
    color: var(--color-brand);
    text-decoration: none;
    cursor: pointer;
  }
  .mobile-top-bar .mobile-theme-btn {
    width: 32px; height: 32px;
    border-radius: 50%;
    border: none;
    background: transparent;
    font-size: 1.1rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    -webkit-tap-highlight-color: transparent;
  }
}

/* 移动端顶部条高度变量 */
@media (max-width: 768px) {
  body { --nav-height: 44px; }
  @supports (padding-top: env(safe-area-inset-top)) {
    body { --nav-height: calc(44px + env(safe-area-inset-top)); }
  }
}

/* ── 认证 UI ── */
.auth-area {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

.auth-login-btn {
  background: var(--color-brand, #6b8f44);
  color: #fff;
  border: none;
  border-radius: 8px;
  padding: 0.35rem 0.85rem;
  font-size: 0.85rem;
  cursor: pointer;
  white-space: nowrap;
  transition: opacity 0.2s;
}
.auth-login-btn:hover { opacity: 0.85; }

.auth-user-info {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.85rem;
}
.auth-avatar {
  width: 24px; height: 24px;
  border-radius: 50%;
  object-fit: cover;
}
.auth-avatar-placeholder {
  font-size: 1.2rem;
}
.auth-logout-btn {
  background: none;
  border: 1px solid var(--border-card);
  border-radius: 6px;
  padding: 0.15rem 0.5rem;
  font-size: 0.75rem;
  color: var(--text-tertiary);
  cursor: pointer;
}
.auth-logout-btn:hover { color: var(--text-primary); }