/* Teacher studio styles (Agent C). Depends on tokens from Agent B's tokens.css
   (base layer teacher-base.css). Only teacher-scoped classes. */

.t-shell { max-width: 1240px; margin: 0 auto; padding: 20px; }

/* --- topbar teacher extras --- */
.topbar .t-badge { display: inline-flex; }
.topbar .t-course {
  margin-left: auto;
  display: flex;
  gap: 8px;
  align-items: center;
}
.topbar .t-course input { width: 150px; }
.topbar .t-course input.lang { width: 54px; }

/* --- tabs --- */
.t-tabs { display: flex; gap: 6px; padding: 0 20px; background: var(--teacher-bar);
  border-bottom: 1px solid var(--line); flex-wrap: wrap; }
.t-tab { border: 0; background: none; font: inherit; font-weight: 600; color: var(--muted);
  padding: 12px 14px; cursor: pointer; border-bottom: 2px solid transparent; }
.t-tab.on { color: var(--green); border-bottom-color: var(--green); }
.t-tab:disabled { opacity: .4; cursor: default; }

.t-view { display: none; }
.t-view.on { display: block; }

/* --- shared layout: nav + main --- */
.t-cols { display: grid; grid-template-columns: 300px minmax(0,1fr); gap: 20px; align-items: start; }
@media (max-width: 860px) { .t-cols { grid-template-columns: 1fr; } }

.t-nav .eyebrow { margin: 0 0 10px; }
.t-lesson { border: 1px solid var(--line); border-radius: 9px; margin-bottom: 10px; overflow: hidden; }
.t-lesson-head { display: flex; align-items: center; gap: 6px; padding: 8px 10px;
  background: #f6f9f9; font-weight: 600; font-size: 14px; }
.t-lesson-head .ttl { flex: 1; cursor: pointer; }
.t-lesson.exam .t-lesson-head { background: #fff4e6; }
.t-task { display: flex; align-items: center; gap: 6px; padding: 6px 10px; font-size: 13px;
  cursor: pointer; border-top: 1px solid var(--line); }
.t-task:hover { background: #f2f7f6; }
.t-task.active { background: #e4f1ed; }
.t-task .tid { flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.t-task .dot { color: var(--green); font-size: 11px; }
.t-add { display: flex; gap: 6px; padding: 6px 8px; }
.t-arrows { display: flex; flex-direction: column; line-height: .8; }
.t-arrows button { border: 0; background: none; cursor: pointer; font-size: 11px; color: var(--muted); padding: 0 2px; }

.t-head { display: flex; align-items: center; gap: 10px; margin-bottom: 14px; }
.t-head .title { font-size: 16px; font-weight: 650; }
.t-head .spacer { flex: 1; }

.msg { margin-top: 12px; padding: 9px 12px; border-radius: 8px; font-size: 13px; display: none; }
.msg.ok { background: #e6f4ef; color: #0d5a45; display: block; }
.msg.err { background: #fbe9e7; color: #9b1c11; display: block; }

.t-empty { color: var(--muted); padding: 34px; text-align: center; border: 1px dashed var(--line);
  border-radius: var(--radius); }

.fld { flex: 1; min-width: 180px; }
.lbl { display: block; font-size: 12px; color: var(--muted); margin: 0 0 4px; }
.row { display: flex; gap: 12px; flex-wrap: wrap; align-items: flex-end; }

/* ===== 2a: task builder — stack of blocks ===== */
.stack { display: flex; flex-direction: column; gap: calc(var(--step) * 3); }
.stack-block { border: 1px solid var(--line); border-radius: var(--radius); padding: 14px; }
.stack-block .eyebrow { margin-bottom: 8px; display: flex; align-items: center; gap: 8px; }
.stack-block textarea.txt { min-height: 70px; resize: vertical; }
.slide-drop { background: #f5f8f8; border: 1px dashed var(--line); border-radius: 8px; min-height: 150px;
  display: flex; align-items: center; justify-content: center; overflow: hidden; }
.slide-drop img { width: 100%; height: auto; display: block; }
.slide-drop .empty { color: var(--muted); font-size: 12px; padding: 20px; text-align: center; }
.file-label { display: inline-block; margin-top: 8px; font-size: 12px; color: var(--green);
  cursor: pointer; border: 1px solid var(--green); border-radius: 8px; padding: 6px 10px; }
.file-label input { display: none; }

.settings { margin-top: 16px; }
.mode-pills { display: flex; gap: 8px; flex-wrap: wrap; }

/* upload-mode student preview (2b) */
.stu-preview { border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; max-width: 320px; }
.stu-preview .bar { background: var(--teacher-bar); font-size: 12px; padding: 6px 10px; color: var(--muted); border-bottom: 1px solid var(--line); }
.stu-preview .body { padding: 14px; }
.stu-preview .drop { border: 2px dashed var(--blue); border-radius: 10px; padding: 26px; text-align: center; color: var(--blue); font-size: 13px; }

/* ===== unified task editor: block canvas + settings ===== */
.tb-tools { display: flex; gap: 12px; align-items: flex-start; flex-wrap: wrap; margin-bottom: 14px; }
.tb-tools .palette { display: flex; flex-wrap: wrap; gap: 6px; flex: 1; }
.tb-main { display: grid; grid-template-columns: minmax(0,1fr) 260px; gap: 16px; align-items: start; }
@media (max-width: 980px) { .tb-main { grid-template-columns: 1fr; } }
.tb-side { position: sticky; top: 16px; }
.tb-tools .palette .pal-item { margin-bottom: 0; }

.palette .pal-item { display: flex; align-items: center; gap: 8px; border: 1px solid var(--line);
  border-radius: 8px; padding: 8px 10px; margin-bottom: 6px; cursor: grab; font-size: 13px; background: var(--paper); }
.palette .pal-item:active { cursor: grabbing; }
.canvas { background: repeating-linear-gradient(90deg,#fff,#fff calc(8.333% - 1px),#f3f5f4 8.333%);
  border: 1px solid var(--line); border-radius: var(--radius); min-height: 360px; padding: 10px;
  display: flex; flex-wrap: wrap; gap: 8px; align-content: flex-start; }
.cv-block { border: 1px solid var(--line); border-radius: 8px; background: var(--paper); padding: 8px 10px;
  min-height: 44px; display: flex; flex-direction: column; gap: 4px; cursor: grab; position: relative; }
.cv-block.sel { border-color: var(--green); box-shadow: 0 0 0 2px #e9f4f1; }
.cv-block .cv-type { font-size: 11px; text-transform: uppercase; letter-spacing: .05em; color: var(--muted); }
.cv-block .cv-x { position: absolute; top: 4px; right: 6px; border: 0; background: none; color: var(--muted); cursor: pointer; }
.cv-drag-over { outline: 2px dashed var(--blue); }

/* ===== unified task editor: Editor.js document (WYSIWYG) ===== */
.tb-doc-wrap { display: grid; grid-template-columns: minmax(0,1fr) 260px; gap: 16px; align-items: start; }
@media (max-width: 980px) { .tb-doc-wrap { grid-template-columns: 1fr; } }
.tb-side { position: sticky; top: 16px; }

.tb-doc { border: 1px solid var(--line); border-radius: var(--radius); background: var(--paper);
  min-height: 300px; padding: 8px 12px; }
.tb-doc:focus-within { border-color: var(--green); box-shadow: 0 0 0 2px #e9f4f1; }
.tb-doc-actions { margin-top: 10px; display: flex; gap: 8px; align-items: center; }

/* Editor.js internals tuned to the design system. */
.tb-doc .ce-block__content,
.tb-doc .ce-toolbar__content { max-width: none; }
.tb-doc .cdx-block { padding: 4px 0; }
.tb-doc .ce-paragraph, .tb-doc .ce-header { color: var(--ink); }
.tb-doc .ce-toolbar__plus,
.tb-doc .ce-toolbar__settings-btn { color: var(--green); }
.tb-doc .ce-popover__item-icon,
.tb-doc .ce-inline-toolbar { color: var(--ink); }

/* Custom block-tool cards */
.tb-doc .ne-tool { border: 1px solid var(--line); border-left: 3px solid var(--green);
  border-radius: 8px; background: #fafcfb; padding: 10px 12px; margin: 6px 0;
  display: flex; flex-direction: column; gap: 8px; }
.tb-doc .ne-tool-tag { font-size: 11px; text-transform: uppercase; letter-spacing: .05em;
  color: var(--green); font-weight: 700; }
.tb-doc .ne-tool-note { color: var(--muted); font-size: 13px; }
.tb-doc .ne-field { display: flex; flex-direction: column; gap: 3px; }
.tb-doc .ne-field-lbl { font-size: 12px; color: var(--muted); }
.tb-doc .ne-field-inp { border: 1px solid var(--line); border-radius: 7px; padding: 6px 9px;
  font: inherit; background: var(--paper); color: var(--ink); }
.tb-doc textarea.ne-field-inp { min-height: 60px; resize: vertical; }
.tb-doc .ne-check { display: inline-flex; gap: 8px; align-items: center; font-size: 13px; cursor: pointer; }
.tb-doc .ne-formula-preview { border: 1px dashed var(--line); border-radius: 7px; padding: 10px;
  background: var(--paper); overflow-x: auto; min-height: 40px; }
.tb-doc .ne-slide-preview { margin: 0; }
.tb-doc .ne-slide-preview img { max-width: 100%; border: 1px solid var(--line); border-radius: 7px; display: block; }
.tb-doc .ne-slide-preview.bad img { display: none; }
.tb-doc .ne-slide-preview.bad::after { content: "image unavailable"; color: var(--muted); font-size: 12px; }
.tb-doc .ne-tool-spacer { border-left-color: var(--line); text-align: center; }

/* ===== 5a: skill graph editor ===== */
.graph-wrap { display: grid; grid-template-columns: minmax(0,1fr) 280px; gap: 16px; align-items: start; }
@media (max-width: 860px) { .graph-wrap { grid-template-columns: 1fr; } }
.graph-canvas { position: relative; border: 1px solid var(--line); border-radius: var(--radius);
  background: var(--paper); height: 520px; overflow: auto; }
.graph-canvas svg { position: absolute; inset: 0; width: 100%; height: 100%; pointer-events: none; z-index: 0; }
.gnode { position: absolute; z-index: 1; border: 1px solid var(--line); border-radius: 10px;
  background: var(--paper); padding: 8px 10px; min-width: 120px; cursor: grab; font-size: 13px; user-select: none; }
.gnode.sel { border-color: var(--green); box-shadow: 0 0 0 2px #e9f4f1; }
.gnode .port { position: absolute; width: 12px; height: 12px; border-radius: 50%;
  background: var(--paper); border: 2px solid var(--blue); top: 50%; transform: translateY(-50%); cursor: crosshair; }
.gnode .port.in { left: -7px; }
.gnode .port.out { right: -7px; }
.slider-row { display: flex; align-items: center; gap: 8px; }
.slider-row input[type=range] { flex: 1; }

/* ===== 6a: review queue ===== */
.review-wrap { display: grid; grid-template-columns: 300px minmax(0,1fr) 300px; gap: 16px; align-items: start; }
@media (max-width: 1040px) { .review-wrap { grid-template-columns: 1fr; } }
.rq-item { border: 1px solid var(--line); border-radius: 9px; padding: 10px; margin-bottom: 8px; cursor: pointer; }
.rq-item:hover { background: #f2f7f6; }
.rq-item.active { border-color: var(--green); background: #e9f4f1; }
.rq-item .who { font-weight: 600; font-size: 13px; }
.rq-item .meta { font-size: 12px; color: var(--muted); margin-top: 2px; }
.rq-photo { width: 100%; border: 1px solid var(--line); border-radius: 10px; background: #f5f8f8;
  min-height: 300px; display: flex; align-items: center; justify-content: center; overflow: hidden; }
.rq-photo img { width: 100%; height: auto; display: block; }
.rq-photo .empty { color: var(--muted); font-size: 13px; padding: 30px; }
.ai-box { border: 1px solid var(--line); border-radius: 9px; padding: 10px; font-size: 13px; background: #fafcfb; }
.ai-box .verdict { font-weight: 600; }
.ai-box .verdict.correct { color: var(--green); }
.ai-box .verdict.incorrect { color: var(--red); }
.verdict-pills { display: flex; gap: 8px; flex-wrap: wrap; margin: 8px 0; }
.verdict-pills .pill.on.correct { border-color: var(--green); color: var(--green); background: #e9f4f1; }
.verdict-pills .pill.on.incorrect { border-color: var(--red); color: var(--red); background: #fbe9e7; }
.verdict-pills .pill.on.redo { border-color: var(--blue); color: var(--blue); background: #e8f0f8; }

/* ---- Course landing (course picker) ---------------------------------- */
.t-home { max-width: 1000px; margin: 24px auto; padding: 0 20px; }
.t-home-head { display: flex; align-items: center; justify-content: space-between; gap: 16px; margin-bottom: 16px; }
.t-muted { color: var(--muted); font-size: 13px; }
.t-current { font-weight: 600; color: var(--ink); }
.t-course-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 14px; }
.t-course-card { display: flex; flex-direction: column; gap: 12px; cursor: pointer; transition: border-color .12s, box-shadow .12s; }
.t-course-card:hover { border-color: var(--green); box-shadow: 0 2px 10px rgba(16,107,92,.12); }
.t-course-card-body { flex: 1; }
.t-course-card .btn { align-self: flex-start; }
.t-course-card { position: relative; }
.t-course-card--drill { justify-content: space-between; }
.t-rename { position: absolute; top: 8px; right: 8px; background: none; border: 0; cursor: pointer; font-size: 15px; line-height: 1; opacity: .5; padding: 4px; border-radius: 6px; }
.t-rename:hover { opacity: 1; background: rgba(16,107,92,.10); }
.t-course-chev { align-self: flex-start; color: var(--muted); font-size: 20px; font-weight: 800; }

/* Teacher hierarchy breadcrumbs */
.t-crumbs { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; margin: 6px 0 14px; font-size: 14px; }
.t-crumbs[hidden] { display: none; }
.t-crumb { background: none; border: 0; padding: 0; font: inherit; color: var(--green); cursor: pointer; }
.t-crumb:hover { text-decoration: underline; }
.t-crumb--current { color: var(--muted); cursor: default; }
.t-crumb__sep { color: var(--muted); }