/* ── site-header ── */
.site-header {
  position: relative;
  background: #fff;
  z-index: 100;
}

/* ── 顶部条 ── */
.top-bar {
  height: 34px;
  background: var(--gray-100);
  border-bottom: 1px solid var(--gray-200);
  font-size: var(--font-xs);
  color: var(--gray-600);
}

.top-bar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: var(--container-width);
  max-width: 100%;
  margin: 0 auto;
  height: 34px;
}

.top-stats {
  display: flex;
  gap: 20px;
}

.top-stats strong {
  color: var(--primary-orange);
  font-weight: 700;
  margin: 0 2px;
}

.top-nav {
  display: flex;
  align-items: center;
  gap: 14px;
}

.top-nav a {
  color: var(--gray-600);
  font-size: var(--font-xs);
  white-space: nowrap;
}

.top-nav a:hover {
  color: var(--primary-orange);
}
.top-nav-user {
  color: var(--gray-900);
  font-size: var(--font-xs);
  font-weight: 600;
  white-space: nowrap;
}

/* ── 主头部 ── */
.main-header {
  padding: 0;
  border-bottom: none;
}

.main-header-inner {
  display: flex;
  align-items: center;
  gap: 24px;
  width: var(--container-width);
  max-width: 100%;
  margin: 0 auto;
  height: 96px;
}

.brand-link {
  display: flex;
  align-items: center;
  gap: 10px;
  color: inherit;
  text-decoration: none;
  flex-shrink: 0;
  margin-right: auto;
}

.logo img {
  height: 48px;
  width: auto;
  object-fit: contain;
}

.brand-copy {
  display: flex;
  flex-direction: column;
}

.brand-copy strong {
  font-size: 18px;
  color: var(--gray-900);
  white-space: nowrap;
  font-weight: 700;
}

.brand-copy span {
  font-size: var(--font-xs);
  color: var(--gray-500);
  white-space: nowrap;
  margin-top: 2px;
}

/* ── 搜索区域 ── */
.search-wrap {
  width: 480px;
  flex-shrink: 0;
}

.search-box {
  display: flex;
  height: 42px;
  border: 2px solid var(--primary-orange);
  border-radius: var(--radius-sm);
  overflow: hidden;
  background: #fff;
}

.search-box input {
  flex: 1;
  min-width: 0;
  border: 0;
  padding: 0 16px;
  font-size: var(--font-base);
  outline: 0;
  background: transparent;
}

.search-box button {
  width: 100px;
  border: 0;
  background: var(--primary-gradient);
  color: #fff;
  font-size: var(--font-base);
  font-weight: 700;
  cursor: pointer;
  white-space: nowrap;
  transition: opacity .18s;
}

.search-box button:hover {
  opacity: 0.88;
}

/* ── 免费发布按钮 ── */
.header-publish-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 42px;
  padding: 0 24px;
  border-radius: var(--radius-sm);
  background: linear-gradient(135deg, var(--accent-orange), var(--accent-orange-dark));
  color: #fff;
  font-size: 15px;
  font-weight: 600;
  white-space: nowrap;
  text-decoration: none;
  transition: box-shadow .2s, transform .15s;
  flex-shrink: 0;
}

.header-publish-btn:hover {
  box-shadow: 0 4px 14px rgba(242, 106, 27, .3);
  transform: translateY(-1px);
  color: #fff;
}

/* ── 频道导航 ── */
.channel-nav {
  background: #fff;
  border-top: 1px solid var(--gray-200);
  border-bottom: 1px solid var(--gray-200);
}

.channel-nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: var(--container-width);
  max-width: 100%;
  margin: 0 auto;
  height: 44px;
}

.channel-nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
}

.channel-nav-links a {
  position: relative;
  display: inline-flex;
  align-items: center;
  line-height: 44px;
  font-size: var(--font-base);
  font-weight: 600;
  color: var(--gray-800);
  white-space: nowrap;
}

.channel-nav-links a::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background: var(--primary-orange);
  border-radius: 2px;
  transform: scaleX(0);
  transition: transform .2s;
}

.channel-nav-links a:hover,
.channel-nav-links a.is-active {
  color: var(--primary-orange);
}

.channel-nav-links a:hover::after,
.channel-nav-links a.is-active::after {
  transform: scaleX(1);
}

.channel-nav-hot {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: var(--font-sm);
}

.channel-nav-hot::before {
  content: "热门";
  display: inline-block;
  padding: 1px 6px;
  background: var(--primary-orange-light);
  color: var(--primary-orange);
  font-size: var(--font-xs);
  font-weight: 600;
  border-radius: 3px;
  margin-right: 4px;
}

.channel-nav-hot a {
  display: inline-block;
  padding: 2px 10px;
  color: var(--gray-700);
  white-space: nowrap;
  border-radius: 3px;
  transition: background .15s, color .15s;
}

.channel-nav-hot a:hover {
  color: var(--primary-orange);
  background: var(--primary-orange-light);
}

/* ── 吸顶 slim 模式 ── */
.site-header.is-sticky {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  box-shadow: var(--shadow-sm);
  animation: headerSlideDown .25s ease;
}

.site-header.is-sticky .top-bar {
  display: none;
}

.site-header.is-sticky .main-header-inner {
  height: 56px;
}

.site-header.is-sticky .logo img {
  height: 36px;
  width: auto;
}

.site-header.is-sticky .search-box {
  height: 36px;
  border-radius: var(--radius-sm);
}

.site-header.is-sticky .header-publish-btn {
  height: 36px;
  padding: 0 16px;
  font-size: var(--font-sm);
}

.site-header.is-sticky .channel-nav {
  display: none;
}

@keyframes headerSlideDown {
  from { transform: translateY(-100%); }
  to { transform: translateY(0); }
}

/* ── header 占位（吸顶时防跳） ── */
.header-placeholder {
  display: none;
}

.header-placeholder.is-visible {
  display: block;
}

/* ── 汉堡菜单按钮 ── */
.mobile-menu-btn {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 36px;
  height: 36px;
  padding: 0;
  border: none;
  background: none;
  cursor: pointer;
  flex-shrink: 0;
}
.mobile-menu-btn span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--gray-800);
  border-radius: 2px;
  transition: transform .2s, opacity .2s;
}
.mobile-menu-btn.is-active span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.mobile-menu-btn.is-active span:nth-child(2) { opacity: 0; }
.mobile-menu-btn.is-active span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ── 响应式 ── */
@media (max-width: 1220px) {
  .top-bar-inner,
  .main-header-inner,
  .channel-nav-inner {
    width: 1000px;
    max-width: 100%;
  }
  .channel-nav-links { gap: 24px; }
  .main-header-inner { gap: 24px; }
}

@media (max-width: 1024px) {
  .main-header-inner {
    flex-wrap: wrap;
    height: auto;
    padding: 12px 0;
  }
  .search-wrap {
    max-width: 100%;
    order: 3;
    width: 100%;
  }
  .header-publish-btn { order: 2; }
}

@media (max-width: 768px) {
  .top-bar { display: none; }
  .main-header-inner {
    height: 56px;
    padding: 0 12px;
    gap: 10px;
    flex-wrap: nowrap;
  }
  .brand-copy { display: none; }
  .logo img { height: 32px; }
  .search-wrap { flex: 1; min-width: 0; width: auto; order: unset; }
  .search-box { height: 36px; }
  .search-box button { width: 64px; font-size: 13px; }
  .header-publish-btn { display: none; }
  .mobile-menu-btn { display: flex; }
  .channel-nav {
    display: none;
    border-top: 1px solid var(--gray-200);
  }
  .channel-nav.is-open { display: block; }
  .channel-nav-inner {
    flex-direction: column;
    height: auto;
    padding: 8px 0;
    align-items: stretch;
  }
  .channel-nav-links {
    flex-direction: column;
    gap: 0;
  }
  .channel-nav-links a {
    line-height: 44px;
    padding: 0 16px;
    border-bottom: 1px solid var(--gray-100);
  }
  .channel-nav-links a::after { display: none; }
  .channel-nav-hot { display: none; }
}