/* ============================================================
   header.css — 导航栏样式（所有页面共用）
   结构：左侧 logo + 导航，右侧 主题切换 + 语言切换
   ============================================================ */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-h);
  background: var(--header-bg);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  gap: 1.6rem;
  height: var(--header-h);
}

/* ---------- 左侧：logo + 导航 ---------- */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  font-weight: 800;
  font-size: 1.1rem;
  letter-spacing: 0.02em;
  flex-shrink: 0;
}

.logo-mark {
  height: 34px;
  width: auto;
  border-radius: 9px;
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  flex: 1;
}

.nav-link {
  padding: 0.42rem 0.95rem;
  border-radius: 999px;
  color: var(--text-2);
  font-weight: 500;
  font-size: 0.95rem;
  transition: all 0.2s ease;
}

.nav-link:hover {
  color: var(--text);
  background: var(--surface-2);
}

.nav-link.active {
  color: var(--primary);
  background: var(--primary-soft);
  font-weight: 600;
}

/* ---------- 右侧：主题 + 语言 ---------- */
.header-actions {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  flex-shrink: 0;
}

/* 汉堡按钮：仅移动端显示，用于打开侧边抽屉导航 */
.header-burger {
  display: none;
  width: 38px;
  height: 38px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--surface);
  place-items: center;
  color: var(--text-2);
  transition: all 0.2s ease;
}

.header-burger:hover {
  color: var(--primary);
  border-color: var(--primary);
}

/* ---------- 字号快捷调节 ---------- */
.font-size-controls {
  display: inline-flex;
  align-items: center;
  height: 34px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--surface);
  overflow: hidden;
}

.font-size-btn {
  width: 30px;
  height: 34px;
  display: grid;
  place-items: center;
  color: var(--text-2);
  font-size: 0.82rem;
  transition: all 0.2s ease;
}

.font-size-btn:hover {
  color: var(--primary);
  background: var(--primary-soft);
}

.font-size-label {
  min-width: 38px;
  text-align: center;
  font-size: 0.72rem;
  color: var(--text-2);
  font-variant-numeric: tabular-nums;
}

/* ---------- 字体颜色主题快捷切换 ---------- */
.accent-wrap {
  position: relative;
}

.accent-btn {
  width: 34px;
  height: 34px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--surface);
  display: grid;
  place-items: center;
  color: var(--text-2);
  transition: all 0.2s ease;
}

.accent-btn:hover {
  color: var(--primary);
  border-color: var(--primary);
}

.accent-btn .grad-dot {
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--title-gradient);
}

.accent-popup {
  position: absolute;
  top: calc(100% + 10px);
  right: 0;
  min-width: 150px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-md);
  padding: 0.45rem;
  display: none;
  flex-direction: column;
  gap: 0.2rem;
  z-index: 160;
}

.accent-popup.open {
  display: flex;
}

.accent-option {
  display: flex;
  align-items: center;
  gap: 0.55rem;
  padding: 0.42rem 0.6rem;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  color: var(--text-2);
  cursor: pointer;
  transition: background 0.2s ease;
}

.accent-option:hover {
  background: var(--surface-2);
}

.accent-option.active {
  color: var(--primary);
  font-weight: 600;
}

.accent-swatch {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  flex-shrink: 0;
}

.theme-toggle {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--surface);
  display: grid;
  place-items: center;
  color: var(--text-2);
  transition: all 0.2s ease;
}

.theme-toggle:hover {
  color: var(--primary);
  border-color: var(--primary);
  box-shadow: var(--shadow-sm);
}

.theme-toggle .icon-moon {
  display: none;
}

[data-theme="dark"] .theme-toggle .icon-sun {
  display: none;
}

[data-theme="dark"] .theme-toggle .icon-moon {
  display: block;
}

.lang-switch {
  display: inline-flex;
  align-items: center;
  border: 1px solid var(--border);
  border-radius: 999px;
  overflow: hidden;
  background: var(--surface);
  font-size: 0.85rem;
}

.lang-divider {
  width: 1px;
  height: 14px;
  background: var(--border);
}

.lang-item {
  padding: 0.32rem 0.85rem;
  color: var(--text-2);
  font-weight: 500;
  transition: all 0.2s ease;
}

.lang-item:not(.active):hover {
  color: var(--primary);
  background: var(--primary-soft);
}

.lang-item.active {
  background: var(--primary);
  color: #fff;
  font-weight: 600;
}

/* ---------- 响应式 ---------- */
@media (max-width: 1100px) {
  .header-burger {
    display: grid;
  }

  /* 移动端顶栏只保留 logo + 汉堡，其余都收进抽屉 */
  .main-nav {
    display: none;
  }

  .header-inner {
    justify-content: space-between;
  }

  .header-actions .theme-toggle,
  .header-actions .lang-switch,
  .header-actions .font-size-controls,
  .header-actions .accent-wrap {
    display: none;
  }
}

@media (max-width: 720px) {
  .header-inner {
    gap: 0.8rem;
  }

  .main-nav {
    gap: 0;
  }

  .nav-link {
    padding: 0.4rem 0.62rem;
    font-size: 0.88rem;
  }

  .lang-item {
    padding: 0.3rem 0.6rem;
  }

  .theme-toggle {
    width: 36px;
    height: 36px;
  }
}

@media (max-width: 520px) {
  .brand-name {
    display: none;
  }
}