/*
 * Schola — 导航 & 页脚样式
 * 依赖 design-system.css 中定义的 CSS 变量
 */

/* ============================================================
   顶部导航
   ============================================================ */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--color-bg);
  border-bottom: 1px solid var(--color-divider);
  transition: var(--transition-theme);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.site-nav .container {
  display: flex;
  flex-direction: column;
}

.site-nav nav {
  display: flex;
  align-items: center;
  gap: 1rem;
  height: 60px;
}

/* Logo */
.nav-logo {
  display: flex;
  align-items: center;
  flex-shrink: 0;
  text-decoration: none;
}
.logo-svg { height: 28px; width: auto; }

/* 导航链接列表 */
.nav-links {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  list-style: none;
  margin-left: 1.5rem;
  flex: 1;
}
.nav-link {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  padding: 0.375rem 0.75rem;
  border-radius: var(--radius-pill);
  transition: color var(--transition-btn), background-color var(--transition-btn);
  text-decoration: none;
}
.nav-link:hover,
.nav-link.active {
  color: var(--color-text-primary);
  background-color: var(--color-brand-light);
}

/* 右侧操作区 */
.nav-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-left: auto;
}

/* 主题切换按钮 */
.nav-theme-btn {
  padding: 0.5rem;
  min-height: auto;
  border-radius: var(--radius-pill);
  color: var(--color-text-secondary);
}
.nav-theme-btn:hover { color: var(--color-brand); }

/* 语言切换 */
.nav-lang-menu { position: relative; }

.nav-lang-btn {
  display: flex;
  align-items: center;
  gap: 5px;
  padding: 0.375rem 0.625rem;
  min-height: auto;
  font-size: var(--text-xs);
  font-weight: 500;
  color: var(--color-text-secondary);
  border-radius: var(--radius-pill);
}
.nav-lang-btn:hover { color: var(--color-brand); }
.nav-lang-label { font-size: 12px; }

.nav-lang-dropdown {
  min-width: 130px;
}
.nav-dropdown-item--active {
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: var(--color-brand);
  font-weight: 500;
}

/* 用户头像按钮 */
.nav-avatar-btn {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-pill);
  background-color: var(--color-brand);
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: opacity var(--transition-btn);
}
.nav-avatar-btn:hover { opacity: 0.85; }

.nav-avatar-initials {
  font-size: 14px;
  font-weight: 600;
  color: #fff;
  text-transform: uppercase;
  font-family: var(--font-body);
}

/* 用户下拉菜单 */
.nav-user-menu { position: relative; }

.nav-dropdown {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  min-width: 200px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-card);
  box-shadow: var(--shadow-lg);
  padding: 0.5rem;
  z-index: 200;
}
.nav-dropdown-user {
  padding: 0.375rem 0.75rem 0.625rem;
}
.nav-dropdown-email {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  display: block;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.nav-dropdown-item {
  display: block;
  width: 100%;
  padding: 0.5rem 0.75rem;
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  border-radius: 6px;
  border: none;
  background: none;
  cursor: pointer;
  text-align: left;
  text-decoration: none;
  font-family: var(--font-body);
  transition: background-color var(--transition-btn), color var(--transition-btn);
}
.nav-dropdown-item:hover {
  background-color: var(--color-brand-light);
  color: var(--color-brand);
}
.nav-dropdown-item--danger { color: var(--color-error); }
.nav-dropdown-item--danger:hover {
  background-color: #FDF0EF;
  color: var(--color-error);
}

/* 汉堡菜单按钮 */
.nav-hamburger {
  background: none;
  border: none;
  cursor: pointer;
  color: var(--color-text-secondary);
  padding: 0.375rem;
  border-radius: 6px;
  min-height: 44px;
  min-width: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.nav-hamburger:hover { background-color: var(--color-brand-light); }

/* 移动端展开菜单 */
.nav-mobile {
  display: flex;
  flex-direction: column;
  padding-bottom: 1rem;
  border-top: 1px solid var(--color-divider);
}
.nav-mobile-link {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  padding: 0.75rem 0;
  border-bottom: 1px solid var(--color-divider);
  text-decoration: none;
}
.nav-mobile-link:last-of-type { border-bottom: none; }
.nav-mobile-link:hover { color: var(--color-brand); }

/* ============================================================
   页脚
   ============================================================ */
.site-footer {
  background-color: var(--color-surface);
  border-top: 1px solid var(--color-divider);
  padding-block: 3rem 2rem;
  margin-top: var(--section-gap);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 2rem;
  margin-bottom: 2rem;
}

@media (max-width: 899px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
  .footer-brand {
    grid-column: 1 / -1;
  }
}

@media (max-width: 599px) {
  .footer-grid {
    grid-template-columns: 1fr;
  }
}

.footer-logo { margin-bottom: 0.875rem; }

.footer-tagline {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.6;
}

.footer-heading {
  font-size: var(--text-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-muted);
  margin-bottom: 0.875rem;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
.footer-links a {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  text-decoration: none;
  transition: color var(--transition-btn);
}
.footer-links a:hover { color: var(--color-brand); }

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 2rem;
  justify-content: space-between;
  align-items: flex-start;
}

.footer-copy {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
}
.footer-copy a { color: var(--color-text-muted); }
.footer-copy a:hover { color: var(--color-brand); }

.footer-disclaimer {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  max-width: 480px;
}