/* Lập trình kéo thả (/cong-cu/blockly). Tệp nạp ở mọi trang → mọi lớp có tiền tố bk-. Ưu tiên màn chiếu 1280–1920px. */
.chinh:has(> .bk) { max-width: 1700px; }
.bk-dau { margin-bottom: 12px; }
.bk-dau h1 { margin: 0; }
.bk-dau .phu { margin: 2px 0 0; }

.bk-ds { list-style: none; margin: 0 0 14px; padding: 0; display: grid; gap: 10px; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); }
.bk-o { display: flex; gap: 12px; align-items: center; width: 100%; height: 100%; padding: 10px 12px; border: 1px solid var(--vien); border-radius: var(--r);
  background: var(--the); color: var(--chu); font: inherit; text-align: left; cursor: pointer; box-shadow: var(--bong); }
.bk-o:hover { border-color: var(--c-vien); }
.bk-o[aria-pressed="true"] { border-color: var(--c-dam); box-shadow: 0 0 0 2px var(--c-dam); background: var(--c-nhat); }
.bk-o img { flex: none; width: 56px; height: 56px; border-radius: 50%; background: #fff; border: 2px solid var(--nhan); object-fit: cover; }
.bk-o__chu { display: flex; flex-direction: column; min-width: 0; }
.bk-o__chu b { color: var(--c-dam); }
.bk-o__chu small { font-size: .8125rem; color: var(--phu); line-height: 1.4; }

.bk-choi { background: var(--the); border: 1px solid var(--vien); border-radius: var(--r); box-shadow: var(--bong); overflow: hidden; display: flex; flex-direction: column;
  scroll-margin-top: 70px; }
.bk-choi:fullscreen { border-radius: 0; border: 0; }
.bk-thanh { display: flex; flex-wrap: wrap; justify-content: space-between; align-items: center; gap: 8px 12px; padding: 8px 14px; border-bottom: 1px solid var(--vien); }
.bk-thanh h2 { margin: 0; font-size: 1.1rem; }
.bk-thanh .hang-nut { margin: 0; }
.bk-khung { display: block; width: 100%; height: clamp(560px, calc(100vh - 140px), 1100px); border: 0; background: #fff; }
.bk-choi:fullscreen .bk-khung { flex: 1; height: auto; }

@media (max-width: 640px) {
  .bk-ds { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 8px; }
  .bk-o { flex-direction: column; align-items: flex-start; gap: 6px; padding: 10px; }
  .bk-o img { width: 44px; height: 44px; }
  .bk-o__chu small { display: none; }
  .bk-khung { height: calc(100vh - 120px); min-height: 520px; }
}