/* ============================================================================
 * EduToolbox · layout.css
 * 职责：站点顶栏、顶栏下拉菜单、主体布局 grid、分类侧栏、面包屑、
 *       返回按钮、自研工具运行页（header + iframe 自适应）、页脚
 * 依赖：base.css
 * ========================================================================== */

/* ---------------------------------------------------------------------------
 * 1. 站点顶栏
 * ------------------------------------------------------------------------- */
.topnav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.88);
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--border);
  transition: background-color var(--t) var(--ease),
              border-color var(--t) var(--ease);
}

body.dark .topnav { background: rgba(20, 24, 33, 0.85); }

.topnav-inner {
  display: flex;
  align-items: center;
  gap: 28px;
  height: var(--topnav-h);
}

/* Logo */
.logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}

.logo:hover { color: inherit; }

.logo-mark {
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  font-size: 26px;
  color: inherit;
  background: transparent;
  border-radius: 0;
  box-shadow: none;
}

.logo-text {
  display: flex;
  flex-direction: column;
  line-height: 1.15;
}

.logo-text strong {
  font-size: 18px;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--text-1);
}

.logo-text small {
  font-size: 12px;
  color: var(--text-3);
}

/* 主导航 */
.nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 4px;
  flex: 1;
}

.nav-link {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 3px;
  padding: 8px 16px;
  font-size: 15px;
  font-weight: 500;
  color: var(--text-2);
  border-radius: var(--r-pill);
  transition: all var(--t-fast) var(--ease);
  white-space: nowrap;
}

.nav-link:hover {
  color: var(--primary);
  background: var(--primary-soft);
}

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

.caret {
  display: inline-block;
  width: 0;
  height: 0;
  margin-left: 4px;
  vertical-align: middle;
  border: 4px solid transparent;
  border-top-color: currentColor;
  border-bottom: none;
  transition: transform var(--t-fast) var(--ease);
}

.nav-dropdown.open .caret { transform: rotate(180deg); }

/* 顶栏右侧操作 */
.topnav-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}

.submit-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 9px 18px;
  font-size: 14px;
  font-weight: 600;
  color: var(--text-1);
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--r-pill);
  box-shadow: var(--shadow-sm);
  transition: all var(--t-fast) var(--ease);
  white-space: nowrap;
}

.submit-btn:hover {
  color: var(--primary);
  border-color: var(--primary-soft-2);
  transform: translateY(-1px);
  box-shadow: var(--shadow);
}

.theme-btn {
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  font-size: 17px;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 50%;
  box-shadow: var(--shadow-sm);
  transition: all var(--t-fast) var(--ease);
}

.theme-btn:hover {
  transform: translateY(-1px) rotate(15deg);
  box-shadow: var(--shadow);
}

/* ---------------------------------------------------------------------------
 * 2. 顶栏下拉菜单
 * ------------------------------------------------------------------------- */
.nav-dropdown { position: relative; }

.dropdown-menu {
  position: absolute;
  top: calc(100% + 12px);
  left: 50%;
  transform: translateX(-50%) translateY(-6px);
  min-width: 248px;
  max-width: min(320px, 86vw);
  padding: 8px;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--r);
  box-shadow: var(--shadow-lg);
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: all var(--t-fast) var(--ease);
  z-index: 200;
}

/* 悬停展开（桌面） */
@media (hover: hover) {
  .nav-dropdown:hover .dropdown-menu {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
    transform: translateX(-50%) translateY(0);
  }
  .nav-dropdown:hover .caret { transform: rotate(180deg); }
}

/* 触屏/点击展开 */
.nav-dropdown.open .dropdown-menu {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transform: translateX(-50%) translateY(0);
}

/* 长菜单（分类很多时）整体可滚动但不撑破视口 —— 唯一允许滚动的弹层 */
.dropdown-menu {
  max-height: min(70vh, 560px);
  overflow-y: auto;
}

.dropdown-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 9px 12px;
  font-size: 14px;
  font-weight: 500;
  color: var(--text-2);
  border-radius: var(--r-sm);
  transition: all var(--t-fast) var(--ease);
}

.dropdown-item:hover {
  color: var(--primary);
  background: var(--primary-soft);
}

.dropdown-item-icon {
  display: grid;
  place-items: center;
  width: 30px;
  height: 30px;
  font-size: 16px;
  background: var(--bg-soft);
  border-radius: 9px;
  flex-shrink: 0;
}

.dropdown-item:hover .dropdown-item-icon {
  background: #fff;
  transform: scale(1.06);
}

body.dark .dropdown-item:hover .dropdown-item-icon { background: var(--primary-soft); }

.dropdown-item-count {
  margin-left: auto;
  font-size: 12px;
  color: var(--text-3);
}

/* ---------------------------------------------------------------------------
 * 3. 主体布局
 * ------------------------------------------------------------------------- */
.main { padding: 28px 0 64px; flex: 1; }

.layout {
  display: grid;
  grid-template-columns: 232px minmax(0, 1fr);
  gap: 28px;
  align-items: start;
}

.layout.no-sidebar { grid-template-columns: minmax(0, 1fr); }

/* 分类侧栏 */
.sidebar {
  position: sticky;
  top: calc(var(--topnav-h) + 20px);
  padding: 14px;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--r);
  box-shadow: var(--shadow-sm);
}

.sidebar-title {
  padding: 6px 10px 12px;
  font-size: 14px;
  font-weight: 700;
  color: var(--text-1);
}

.cat-list li + li { margin-top: 2px; }

.cat-item {
  display: flex;
  align-items: center;
  gap: 9px;
  padding: 9px 12px;
  font-size: 14px;
  color: var(--text-2);
  border-radius: var(--r-sm);
  transition: all var(--t-fast) var(--ease);
}

.cat-item:hover {
  color: var(--primary);
  background: var(--primary-soft);
}

.cat-item.active {
  color: #fff;
  background: var(--primary-grad);
  font-weight: 600;
  box-shadow: var(--shadow-primary);
}

.cat-icon { font-size: 16px; }
.cat-name { flex: 1; }

.cat-count {
  font-size: 12px;
  color: var(--text-3);
  padding: 1px 8px;
  background: var(--bg-soft);
  border-radius: var(--r-pill);
}

.cat-item.active .cat-count {
  color: #fff;
  background: rgba(255, 255, 255, 0.22);
}

/* 内容列 */
.content { min-width: 0; }

.content-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 20px;
}

.content-head h2 { font-size: 22px; }

.result-count {
  font-size: 13px;
  color: var(--text-3);
}

/* ---------------------------------------------------------------------------
 * 4. 面包屑 / 返回按钮 / 分类页头部
 * ------------------------------------------------------------------------- */
.cp-breadcrumb,
.breadcrumb {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  font-size: 13px;
  color: var(--text-3);
  margin-bottom: 16px;
}

.cp-breadcrumb a,
.breadcrumb a {
  color: var(--text-2);
  transition: color var(--t-fast) var(--ease);
}

.cp-breadcrumb a:hover,
.breadcrumb a:hover { color: var(--primary); }

.cp-breadcrumb .sep,
.breadcrumb .sep { color: var(--text-3); }

.cp-breadcrumb-cur,
.breadcrumb .current { color: var(--text-1); font-weight: 500; }

.cp-breadcrumb-static { margin-bottom: 14px; }

.back-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-bottom: 18px;
  padding: 9px 20px;
  font-size: 14px;
  font-weight: 600;
  color: var(--text-2);
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--r-pill);
  box-shadow: var(--shadow-sm);
  transition: all var(--t-fast) var(--ease);
}

.back-btn:hover {
  color: var(--primary);
  border-color: var(--primary-soft-2);
  transform: translateX(-2px);
}

/* 分类页动态头部：面包屑左对齐，标题副标题居中 */
.category-page-header {
  margin-bottom: 26px;
  text-align: center;
}

.category-page-header .cp-breadcrumb {
  justify-content: flex-start;
}

.category-page-header .cp-title {
  text-align: center;
}

.category-page-header .cp-desc {
  margin-left: auto;
  margin-right: auto;
}

.cp-title {
  font-size: clamp(26px, 3.4vw, 36px);
  font-weight: 800;
  letter-spacing: -0.01em;
  margin-bottom: 10px;
}

.cp-desc {
  font-size: 15px;
  color: var(--text-2);
  max-width: 760px;
}

/* ---------------------------------------------------------------------------
 * 5. 自研工具运行页（iframe 高度自适应：不设固定高度，不出现内部滚动条）
 * ------------------------------------------------------------------------- */
.tool-run-header {
  padding: 28px 32px;
  margin-bottom: 22px;
  text-align: center;
  background: var(--primary-grad);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow-primary);
  color: #fff;
}

.tool-run-title-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  margin-bottom: 8px;
}

.tool-run-icon { font-size: 38px; line-height: 1; }

.tool-run-title-row h1 {
  color: #fff;
  font-size: clamp(24px, 3vw, 32px);
  font-weight: 800;
}

.tool-run-badge {
  padding: 3px 12px;
  font-size: 12px;
  font-weight: 700;
  color: #fff;
  background: rgba(255, 255, 255, 0.25);
  border: 1px solid rgba(255, 255, 255, 0.4);
  border-radius: var(--r-pill);
}

.tool-run-sub {
  color: rgba(255, 255, 255, 0.92);
  font-size: 14.5px;
  line-height: 1.7;
  max-width: 880px;
  margin: 0 auto 14px;
}

.tool-run-features {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
}

.tool-feature {
  padding: 6px 16px;
  font-size: 13px;
  font-weight: 600;
  color: #fff;
  background: rgba(255, 255, 255, 0.18);
  border: 1px solid rgba(255, 255, 255, 0.28);
  border-radius: var(--r-pill);
}

/* iframe 外框：随工具内容自动撑高（router.js 用 ResizeObserver 同步高度） */
.tool-iframe-wrap {
  position: relative;
  width: 100%;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow);
  overflow: hidden; /* 裁掉 iframe 圆角；高度随内容增长，不产生滚动条 */
}

#toolIframe {
  display: block;
  width: 100%;
  min-width: 100%;
  border: 0;
  /* JS 按内容实际高度同步；兜底最小高度保证空内容时也有展示区 */
  min-height: 70vh;
  background: var(--bg);
  overflow: hidden; /* 正常高度同步下不显示 iframe 内滚动条 */
}

/* ---------------------------------------------------------------------------
 * 6. 通用页面（.page 切换由 router 控制 hidden）
 * ------------------------------------------------------------------------- */
.page { padding-bottom: 64px; }

.page-title {
  font-size: clamp(24px, 3vw, 32px);
  font-weight: 800;
  margin-bottom: 8px;
}

.page-desc {
  font-size: 15px;
  color: var(--text-2);
  margin-bottom: 28px;
}

/* 空状态（布局兜底，主要样式见 components.css） */
.empty-state { margin-top: 60px; }

/* ---------------------------------------------------------------------------
 * 7. 页脚
 * ------------------------------------------------------------------------- */
#app {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.footer {
  margin-top: auto;
  padding: 40px 0 48px;
  background: var(--card-bg);
  border-top: 1px solid var(--border);
  color: var(--text-3);
}

.footer-inner {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 40px;
  flex-wrap: wrap;
}

.footer strong {
  display: block;
  font-size: 16px;
  color: var(--text-1);
  margin-bottom: 8px;
}

.footer p {
  max-width: 560px;
  font-size: 13px;
  line-height: 1.8;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 22px;
  font-size: 14px;
}

.footer-links a { color: var(--text-2); }
.footer-links a:hover { color: var(--primary); }