/* pages/lesson.css —— 授课计划。
   外壳、校园页头、按钮、KPI、筛选胶囊与卡片皮肤复用全站组件；
   此处仅维护学期、部门目录、课程时间线与编辑器的专属布局。 */

/* 页头和部门导航：沿用 layout.css / components.css */
.page-lesson .lesson-plan-actions { margin-top: var(--space-4); }
.page-lesson .lesson-kpi strong { font-variant-numeric: tabular-nums; }
.page-lesson .lesson-kpi strong [data-count] { margin: 0; color: inherit; font: inherit; }
.page-lesson .lesson-department-nav { margin-bottom: var(--space-6); }
.page-lesson :is(.lesson-department-nav a, .lesson-department-card, .team-term-button, .lesson-links a, .lesson-subscription-toggle):focus-visible {
  outline: 2px solid var(--c-focus);
  outline-offset: 4px;
}

/* 学期选择与章节标题 */
.page-lesson .lesson-plan-toolbar {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: var(--space-4) var(--space-6);
  margin-bottom: var(--space-6);
}
.page-lesson .lesson-toolbar-intro .eyebrow { margin-bottom: var(--space-2); }
.page-lesson .lesson-toolbar-intro h2 { font-size: var(--fs-2xl); }
.page-lesson .lesson-toolbar-group { display: grid; gap: var(--space-2); min-width: 0; max-width: 100%; }
.page-lesson .lesson-toolbar-label { color: var(--c-text-2); font-size: var(--fs-xs); font-weight: 600; }
.page-lesson .team-term-button { gap: var(--space-2); min-height: 36px; }
.page-lesson .team-term-button > span { color: var(--c-text-3); font-size: var(--fs-xs); font-weight: 400; font-variant-numeric: tabular-nums; }
.page-lesson .team-term-button.is-active > span { color: var(--c-brand); }
.page-lesson .lesson-term-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: var(--space-2) var(--space-4);
  margin-bottom: var(--space-6);
  padding-bottom: var(--space-4);
  border-bottom: 1px solid var(--c-line);
}
.page-lesson .lesson-term-head h2 { font-size: var(--fs-2xl); }
.page-lesson .lesson-term-note { color: var(--c-text-2); font-size: var(--fs-sm); }
.page-lesson .lesson-term-stats {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1) var(--space-3);
  margin-left: auto;
  color: var(--c-text-3);
  font-size: var(--fs-xs);
  font-variant-numeric: tabular-nums;
}
.page-lesson .lesson-term-stats > span + span::before { content: "·"; margin-right: var(--space-3); }
.page-lesson .lesson-section-heading { margin-bottom: var(--space-5); }
.page-lesson .lesson-section-heading .eyebrow { margin-bottom: var(--space-2); }
.page-lesson .lesson-section-heading h3 { font-size: var(--fs-2xl); }
.page-lesson .lesson-section-heading p:not(.eyebrow) { max-width: var(--max-prose); margin-top: var(--space-3); color: var(--c-text-2); }

/* 部门课表目录：与项目页相同的两列卡片 */
.page-lesson .lesson-department-overview { margin-bottom: var(--section-gap); }
.page-lesson .lesson-department-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: var(--space-5); }
.page-lesson .lesson-department-card {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  min-width: 0;
  color: var(--c-text);
  overflow-wrap: anywhere;
}
.page-lesson .lesson-department-card-top { display: flex; align-items: center; justify-content: space-between; gap: var(--space-3); }
.page-lesson .lesson-department-index { color: var(--c-brand-strong); font-family: var(--font-mono); font-size: var(--fs-sm); font-variant-numeric: tabular-nums; }
.page-lesson .lesson-department-code { color: var(--c-text-3); font-family: var(--font-mono); font-size: var(--fs-xs); letter-spacing: .06em; }
.page-lesson .lesson-department-card h3 { font-size: var(--fs-xl); }
.page-lesson .lesson-department-theme { color: var(--c-text-2); white-space: pre-line; }
.page-lesson .lesson-department-card-foot { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: var(--space-3); margin-top: auto; padding-top: var(--space-3); border-top: 1px solid var(--c-line); }
.page-lesson .lesson-department-card-foot .meta { font-size: var(--fs-xs); }
.page-lesson .lesson-department-go { display: inline-flex; align-items: center; gap: var(--space-2); color: var(--c-brand-strong); font-size: var(--fs-sm); font-weight: 600; }
.page-lesson .lesson-department-card.is-public { grid-column: 1 / -1; }

/* 部门学期主题：标准卡片上的浅蓝品牌强调 */
.page-lesson .lesson-term-theme {
  display: grid;
  gap: var(--space-3);
  margin-bottom: var(--space-6);
  border-color: rgba(var(--brand-rgb), .18);
  background: linear-gradient(110deg, var(--blue-50), var(--c-surface));
  overflow-wrap: anywhere;
}
.page-lesson .lesson-term-theme .eyebrow { margin: 0; }
.page-lesson .lesson-term-theme h3 { font-size: var(--fs-2xl); line-height: 1.5; white-space: pre-line; }
.page-lesson .lesson-term-theme p:not(.eyebrow) { color: var(--c-text-2); white-space: pre-line; }

/* 下一次课：日期牌与课程摘要 */
.page-lesson .lesson-highlight {
  display: grid;
  grid-template-columns: 160px minmax(0, 1fr);
  align-items: center;
  gap: var(--space-6);
  margin-bottom: var(--space-7);
  border-color: rgba(var(--brand-rgb), .18);
  background: linear-gradient(180deg, var(--blue-50), var(--c-surface));
}
.page-lesson .lesson-highlight-date {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: var(--space-4);
  border: 1px solid var(--c-line);
  border-radius: var(--r-lg);
  background: var(--c-surface);
  box-shadow: var(--shadow-sm);
  text-align: center;
}
.page-lesson .lesson-highlight-month { color: var(--c-text-3); font-family: var(--font-mono); font-size: var(--fs-2xs); letter-spacing: var(--tracking-eyebrow); text-transform: uppercase; }
.page-lesson .lesson-highlight-day { color: var(--c-brand-strong); font-family: var(--font-display); font-size: 64px; font-weight: 700; line-height: 1.1; font-variant-numeric: tabular-nums; letter-spacing: var(--tracking-display); }
.page-lesson .lesson-highlight-weekday { color: var(--c-text-2); font-size: var(--fs-sm); }
.page-lesson .lesson-highlight-countdown { margin-top: var(--space-3); padding: var(--space-1) var(--space-3); border-radius: var(--r-pill); background: var(--c-brand-soft); color: var(--c-brand-strong); font-size: var(--fs-xs); font-weight: 600; white-space: nowrap; }
.page-lesson .lesson-highlight-body { display: grid; gap: var(--space-4); min-width: 0; }
.page-lesson .lesson-highlight-head { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: var(--space-3); }
.page-lesson .lesson-highlight-head .eyebrow { margin: 0; }
.page-lesson .lesson-highlight h3 { font-size: var(--fs-2xl); line-height: 1.4; overflow-wrap: anywhere; }
.page-lesson .lesson-highlight .lesson-facts { display: flex; flex-wrap: wrap; padding-top: var(--space-4); border-top: 1px solid var(--c-line); }

/* 状态胶囊与课程信息 */
.page-lesson .lesson-status { display: inline-flex; align-items: center; flex: none; gap: 6px; min-height: 24px; padding: 2px 10px; border: 1px solid var(--c-line); border-radius: var(--r-pill); background: var(--c-surface); color: var(--c-text-2); font-size: var(--fs-xs); font-weight: 600; white-space: nowrap; }
.page-lesson .lesson-status::before { content: ""; width: 6px; height: 6px; border-radius: 50%; }
.page-lesson .lesson-status.is-planned { border-color: rgba(var(--brand-rgb), .3); color: var(--c-brand-strong); }
.page-lesson .lesson-status.is-planned::before { border: 1.5px solid var(--c-brand); }
.page-lesson .lesson-status.is-completed { border-color: transparent; background: var(--c-brand-soft); color: var(--c-brand-strong); }
.page-lesson .lesson-status.is-completed::before { background: var(--c-brand); }
.page-lesson .lesson-status.is-cancelled { background: var(--c-surface-2); color: var(--c-text-3); }
.page-lesson .lesson-status.is-cancelled::before { background: var(--c-text-3); }
.page-lesson .lesson-facts { display: grid; gap: var(--space-2) var(--space-5); margin: 0; }
.page-lesson .lesson-fact { display: flex; align-items: baseline; gap: var(--space-2); min-width: 0; }
.page-lesson .lesson-fact dt { flex: none; color: var(--c-text-3); font-size: var(--fs-xs); font-weight: 500; }
.page-lesson .lesson-fact dd { margin: 0; min-width: 0; color: var(--c-text); font-size: var(--fs-sm); overflow-wrap: anywhere; }

/* 每次课的资料：标题与直达按钮单独成行，下一次课和时间线共用。 */
.page-lesson .lesson-resources {
  display: grid;
  grid-template-columns: max-content minmax(0, 1fr);
  align-items: start;
  gap: var(--space-3) var(--space-4);
  min-width: 0;
  padding-top: var(--space-4);
  border-top: 1px solid var(--c-line);
}
.page-lesson .lesson-resources-title {
  display: flex;
  align-items: center;
  min-height: 40px;
  margin: 0;
  color: var(--c-text-2);
  font-size: var(--fs-sm);
  font-weight: 500;
}
.page-lesson .lesson-links { display: flex; flex-wrap: wrap; gap: var(--space-2); min-width: 0; }
.page-lesson .lesson-links a {
  display: inline-flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  min-width: 0;
  min-height: 40px;
  max-width: 100%;
  padding: var(--space-2) var(--space-4);
  border: 1px solid var(--c-line);
  border-radius: var(--r-pill);
  background: var(--c-brand-soft);
  color: var(--c-brand-strong);
  font-size: var(--fs-sm);
  font-weight: 600;
  line-height: var(--lh-heading);
  transition: border-color var(--motion), color var(--motion), background-color var(--motion);
}
.page-lesson .lesson-links a:hover { border-color: var(--c-brand); background: var(--c-surface); color: var(--c-brand-hover); }
.page-lesson .lesson-link-label { min-width: 0; overflow-wrap: anywhere; }

/* 日历订阅：标准卡片内按需展开 */
.page-lesson .lesson-subscription { margin-bottom: var(--space-6); padding-block: var(--space-3); }
.page-lesson .lesson-subscription-toggle { display: flex; flex-wrap: wrap; align-items: center; gap: var(--space-2) var(--space-3); min-height: 44px; color: var(--c-brand-strong); font-size: var(--fs-sm); font-weight: 600; list-style: none; cursor: pointer; }
.page-lesson .lesson-subscription-toggle::-webkit-details-marker { display: none; }
.page-lesson .lesson-subscription-toggle::after { content: "+"; margin-left: auto; font-family: var(--font-mono); font-size: var(--fs-lg); font-weight: 400; }
.page-lesson .lesson-subscription[open] > .lesson-subscription-toggle::after { content: "−"; }
.page-lesson .lesson-subscription-toggle .meta { color: var(--c-text-3); font-size: var(--fs-xs); font-weight: 400; }
.page-lesson .lesson-subscription-body { display: grid; gap: var(--space-3); padding-block: var(--space-3); border-top: 1px solid var(--c-line); }
.page-lesson .lesson-subscription-actions { display: flex; flex-wrap: wrap; gap: var(--space-2); }
.page-lesson .lesson-subscription .meta { margin: 0; }
.page-lesson .lesson-subscription-fallback input { width: 100%; margin-top: var(--space-2); }

/* 课程时间线：日期列、节点和全站标准卡片。
   竖线挂在每个课次自己的 li 上（104px 日期列 + 40px 节点列，中线在 123px），
   从本课次的节点连到下一课次的节点，最后一张不再往下画：
   既不会在第一颗节点上方留一截线头，也不会越过最后一颗节点继续往卡片旁边伸。 */
.page-lesson .lesson-timeline { display: grid; gap: var(--space-4); margin: 0; padding: 0; list-style: none; }
.page-lesson .lesson-card { position: relative; display: grid; grid-template-columns: 104px 40px minmax(0, 1fr); align-items: start; }
.page-lesson .lesson-card::before {
  content: "";
  position: absolute;
  top: 30px;
  left: 123px;
  width: 1px;
  height: calc(100% + var(--space-4));
  background: var(--c-line-strong);
}
.page-lesson .lesson-card:last-child::before { content: none; }
.page-lesson .lesson-when { display: grid; justify-items: end; gap: var(--space-1); padding-top: var(--space-5); text-align: right; }
.page-lesson .lesson-date { color: var(--c-text); font-family: var(--font-display); font-size: var(--fs-xl); font-weight: 600; line-height: 1.1; font-variant-numeric: tabular-nums; letter-spacing: var(--tracking-heading); }
.page-lesson .lesson-date.is-tbd { color: var(--c-text-3); font-size: var(--fs-lg); }
.page-lesson .lesson-weekday { color: var(--c-text-3); font-family: var(--font-mono); font-size: var(--fs-xs); white-space: nowrap; }
.page-lesson .lesson-node { position: relative; z-index: 1; justify-self: center; width: 11px; height: 11px; margin-top: 30px; border: 2px solid var(--c-brand); border-radius: 50%; background: var(--c-surface); }
.page-lesson .lesson-card.is-completed .lesson-node { background: var(--c-brand); }
.page-lesson .lesson-card.is-cancelled .lesson-node { border-color: var(--c-line-strong); background: var(--c-surface-2); }
.page-lesson .lesson-card.is-next .lesson-node { background: var(--c-brand); box-shadow: 0 0 0 4px rgba(var(--brand-rgb), .15); }
.page-lesson .lesson-card-body { display: grid; gap: var(--space-3); min-width: 0; }
.page-lesson .lesson-card.is-next .lesson-card-body { border-color: rgba(var(--brand-rgb), .35); background: linear-gradient(180deg, var(--blue-50), var(--c-surface) 70%); }
.page-lesson .lesson-card-top { display: flex; align-items: center; justify-content: space-between; gap: var(--space-3); }
.page-lesson .lesson-card-tags { display: flex; flex-wrap: wrap; align-items: center; gap: var(--space-2); min-width: 0; }
.page-lesson .lesson-card-tags:empty { display: none; }
.page-lesson .lesson-session { color: var(--c-brand-strong); font-family: var(--font-mono); font-size: var(--fs-xs); font-weight: 600; white-space: nowrap; }
.page-lesson .lesson-card-body > h3 { font-size: var(--fs-lg); line-height: 1.4; overflow-wrap: anywhere; }
.page-lesson .lesson-card-body > .lesson-facts { display: flex; flex-wrap: wrap; }
.page-lesson .lesson-card-time { color: var(--c-text-2); font-size: var(--fs-sm); }
.page-lesson .lesson-card.is-cancelled .lesson-card-body { background: var(--c-surface-2); }
.page-lesson .lesson-card.is-cancelled .lesson-card-body > h3,
.page-lesson .lesson-card.is-cancelled .lesson-date,
.page-lesson .lesson-card.is-cancelled .lesson-fact dd { color: var(--c-text-3); }
.page-lesson .lesson-card.is-cancelled .lesson-card-body > h3 s { text-decoration-thickness: 1px; }
.page-lesson .lesson-term-empty { margin-top: var(--space-4); }

/* 空课表 */
.page-lesson .lesson-plan-empty { display: grid; justify-items: center; gap: var(--space-3); max-width: var(--max-prose); margin-inline: auto; padding: var(--space-7) var(--space-5); border: 1px dashed var(--c-line-strong); border-radius: var(--r-xl); background: linear-gradient(180deg, var(--blue-50), var(--c-surface)); text-align: center; }
.page-lesson .lesson-plan-empty-mark { position: relative; width: 44px; height: 40px; margin-bottom: var(--space-2); border: 1.5px solid var(--c-brand); border-top-width: 6px; border-radius: var(--r-sm); }
.page-lesson .lesson-plan-empty-mark::after { content: ""; position: absolute; left: 8px; right: 8px; top: 10px; height: 1.5px; background: var(--c-brand); box-shadow: 0 8px 0 var(--c-brand); }
.page-lesson .lesson-plan-empty h2 { font-size: var(--fs-2xl); }
.page-lesson .lesson-plan-empty > p { max-width: 520px; color: var(--c-text-2); }
.page-lesson .lesson-plan-empty .hero-actions { justify-content: center; margin-top: var(--space-3); }
.page-lesson .lesson-plan-empty-hint { padding: var(--space-3) var(--space-4); border: 1px solid rgba(var(--brand-rgb), .2); border-radius: var(--r-md); background: var(--c-surface); color: var(--c-brand-strong); font-size: var(--fs-sm); }

/* 编辑弹窗 */
.page-lesson .modal-overlay[data-lesson-plan-editor] .modal { max-width: 900px; }
.page-lesson .lesson-plan-editor [data-lesson-plan-terms] { display: grid; gap: var(--space-5); }

.page-lesson .lesson-editor-themes {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--space-3);
}
.page-lesson .lesson-editor-theme {
  display: grid;
  align-content: start;
  gap: var(--space-3);
  min-width: 0;
  margin: 0;
  padding: var(--space-4);
  border: 1px solid var(--c-line);
  border-radius: var(--r-md);
  background: var(--c-surface-2);
}
.page-lesson .lesson-editor-theme h4 { font-size: var(--fs-base); }
.page-lesson .lesson-editor-theme textarea.admin-input { min-height: 90px; resize: vertical; }

.page-lesson .lesson-term-editor {
  display: grid;
  gap: var(--space-4);
  min-width: 0;
  margin: 0;
  padding: var(--space-5);
  border: 1px solid var(--c-line);
  border-radius: var(--r-lg);
  background: var(--c-surface);
  box-shadow: var(--shadow-xs);
}
.page-lesson .lesson-term-editor legend {
  padding: 0 var(--space-2);
  color: var(--c-text);
  font-size: var(--fs-base);
  font-weight: 600;
}
.page-lesson .lesson-term-editor .grid,
.page-lesson .lesson-editor-row .grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--space-3);
}

.page-lesson .lesson-editor-list { display: grid; gap: var(--space-3); counter-reset: lesson-row; }
.page-lesson .lesson-editor-row {
  display: grid;
  gap: var(--space-3);
  padding: var(--space-4);
  border: 1px solid var(--c-line);
  border-radius: var(--r-md);
  background: var(--c-surface-2);
  counter-increment: lesson-row;
}
.page-lesson .lesson-editor-row-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  padding-bottom: var(--space-3);
  border-bottom: 1px solid var(--c-line);
}
.page-lesson .lesson-editor-row-index::before {
  content: "课次 " counter(lesson-row, decimal-leading-zero);
  color: var(--c-brand-strong);
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  font-weight: 600;
  letter-spacing: .06em;
}
.page-lesson .lesson-editor-row .select-input { width: 100%; min-width: 0; }
.page-lesson .lesson-editor-row textarea.admin-input { min-height: 80px; }
.page-lesson .lesson-editor-row-actions { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: var(--space-2); }
.page-lesson .lesson-editor-empty {
  padding: var(--space-4);
  border: 1px dashed var(--c-line-strong);
  border-radius: var(--r-md);
  text-align: center;
}

.page-lesson .lesson-term-adder {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr) auto;
  align-items: end;
  gap: var(--space-3);
  padding: var(--space-4);
  border: 1px dashed rgba(var(--brand-rgb), .3);
  border-radius: var(--r-lg);
  background: var(--blue-50);
}
.page-lesson .lesson-term-adder .btn { height: 40px; }
.page-lesson .lesson-plan-editor [data-lesson-plan-message]:empty { display: none; }

/* 断点 */
@media (max-width: 1024px) {
  .page-lesson .lesson-term-adder { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
  .page-lesson .lesson-term-adder .btn { grid-column: 1 / -1; justify-self: start; }
}

@media (max-width: 720px) {
  .page-lesson .lesson-department-nav .filter-chip,
  .page-lesson .team-term-button,
  .page-lesson .lesson-links a { min-height: 44px; }
  .page-lesson .lesson-plan-toolbar { align-items: stretch; gap: var(--space-4); }
  .page-lesson .lesson-toolbar-intro,
  .page-lesson .lesson-toolbar-group { width: 100%; }
  .page-lesson .lesson-term-head { display: grid; gap: var(--space-2); margin-bottom: var(--space-5); }
  .page-lesson .lesson-term-stats { margin-left: 0; }
  .page-lesson .lesson-department-grid { grid-template-columns: 1fr; gap: var(--space-4); }
  .page-lesson .lesson-department-card,
  .page-lesson .lesson-term-theme { padding: var(--space-4); }
  .page-lesson .lesson-term-theme h3 { font-size: var(--fs-xl); }
  .page-lesson .lesson-highlight { grid-template-columns: minmax(0, 1fr); gap: var(--space-5); padding: var(--space-4); }
  .page-lesson .lesson-highlight-date { display: grid; grid-template-columns: auto minmax(0, 1fr); grid-template-areas: "day month" "day weekday" "day countdown"; justify-items: start; gap: 0 var(--space-4); text-align: left; }
  .page-lesson .lesson-highlight-day { grid-area: day; align-self: center; }
  .page-lesson .lesson-highlight-month { grid-area: month; align-self: end; }
  .page-lesson .lesson-highlight-weekday { grid-area: weekday; }
  .page-lesson .lesson-highlight-countdown { grid-area: countdown; margin-top: var(--space-1); }
  .page-lesson .lesson-highlight h3 { font-size: var(--fs-xl); }
  .page-lesson .lesson-resources { grid-template-columns: minmax(0, 1fr); gap: var(--space-2); }
  .page-lesson .lesson-resources-title { min-height: 0; font-size: var(--fs-xs); }
  .page-lesson .lesson-card { grid-template-columns: 20px minmax(0, 1fr); grid-template-areas: "node when" ". body"; column-gap: var(--space-3); row-gap: var(--space-2); }
  .page-lesson .lesson-card::before { top: 6px; left: 9px; }
  .page-lesson .lesson-node { grid-area: node; margin-top: 6px; }
  .page-lesson .lesson-when { grid-area: when; display: flex; flex-wrap: wrap; align-items: baseline; gap: var(--space-2); padding-top: 0; text-align: left; }
  .page-lesson .lesson-date { font-size: var(--fs-lg); }
  .page-lesson .lesson-card-body { grid-area: body; padding: var(--space-4); }
  .page-lesson .lesson-card-top { flex-wrap: wrap; }
  .page-lesson .lesson-plan-empty .hero-actions { width: 100%; }
  .page-lesson .lesson-editor-themes { grid-template-columns: 1fr; }
  .page-lesson .lesson-term-editor,
  .page-lesson .lesson-editor-row { padding: var(--space-3); }
  .page-lesson .lesson-term-editor .grid,
  .page-lesson .lesson-editor-row .grid,
  .page-lesson .lesson-term-adder { grid-template-columns: 1fr; }
  .page-lesson .lesson-term-adder .btn { justify-self: stretch; }
  .page-lesson .lesson-editor-row-head { flex-direction: column; align-items: flex-start; }
  .page-lesson .lesson-editor-row-actions { justify-content: flex-start; }
}

@media (hover: none) {
  .page-lesson .lesson-links a { min-height: 44px; }
}

@media (prefers-reduced-motion: reduce) {
  .page-lesson .lesson-department-card.is-interactive:hover { transform: none; }
}