/* Cờ (/cong-cu/co). Tệp nạp ở mọi trang → mọi lớp có tiền tố co- (gốc là .co-goc, không dùng .co trần). */
.chinh:has(> .co-goc) { max-width: 1280px; }
.co-an-chu { position: absolute !important; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.co-dau h1 { margin: 0; }
.co-dau .phu { margin: 2px 0 12px; }

/* Tab loại cờ */
.co-tab { display: flex; gap: 6px; overflow-x: auto; margin-bottom: 12px; padding-bottom: 2px; }
.co-tab [role="tab"] { flex: none; min-height: 46px; padding: 8px 18px; border-radius: 999px; border: 1px solid var(--vien); background: var(--the);
  color: var(--chu); font: inherit; font-weight: 700; cursor: pointer; }
.co-tab [role="tab"]:hover { border-color: var(--c-vien); color: var(--c-dam); }
.co-tab [role="tab"][aria-selected="true"] { background: var(--c-dam); border-color: var(--c-dam); color: #fff; }

/* Khung: bàn cờ bên trái, bảng điều khiển bên phải (điện thoại: xếp dọc) */
.co-p { background: var(--the); border: 1px solid var(--vien); border-radius: var(--r); box-shadow: var(--bong); padding: clamp(10px, 2vw, 20px); }
.co-p:fullscreen { overflow: auto; border-radius: 0; background: var(--bg); padding: 16px; }
.co-khung { display: grid; gap: 16px; align-items: start; }
@media (min-width: 900px) { .co-khung { grid-template-columns: minmax(0, 1fr) 340px; } }
.co-ban-o { display: flex; flex-direction: column; align-items: center; min-width: 0; }
.co-ban { width: 100%; }
.co-ban--vua { max-width: min(100%, 680px, max(320px, calc(100vh - 275px))); aspect-ratio: 1; }
/* Chữ tọa độ của cm-chessboard nhạt quá trên màn chiếu → đậm hơn */
.co-ban--vua .cm-chessboard.default .coordinates .coordinate { font-weight: 700; }
.co-ban--vua .cm-chessboard.default .coordinates .coordinate.white { fill: #7a5a35; }
.co-ban--vua .cm-chessboard.default .coordinates .coordinate.black { fill: #fbf1dc; }
.co-p:fullscreen .co-ban--vua { max-width: min(100%, calc(100vh - 40px)); }
.co-ban--tuong { max-width: min(100%, 600px, max(300px, calc((100vh - 280px) * .9))); }
.co-p:fullscreen .co-ban--tuong { max-width: min(100%, calc((100vh - 90px) * .9)); }
.co-ban--vay { max-width: min(100%, 680px, max(320px, calc(100vh - 275px))); }
.co-p:fullscreen .co-ban--vay { max-width: min(100%, calc(100vh - 40px)); }
.co-ban--caro { max-width: min(100%, 640px, max(320px, calc(100vh - 275px))); }
.co-p:fullscreen .co-ban--caro { max-width: min(100%, calc(100vh - 40px)); }

.co-ben { display: flex; flex-direction: column; gap: 12px; min-width: 0; }
.co-tt { margin: 0; padding: 10px 14px; border-radius: var(--r-nho); background: var(--c-nhat); color: var(--c-dam); font-weight: 700; min-height: 46px; }
.co-cai { display: grid; gap: 10px; padding: 12px; border: 1px solid var(--vien); border-radius: var(--r-nho); background: var(--bg); }
.co-cai .nut { justify-self: start; }
.co-ben [hidden] { display: none !important; }
.co-h { font-size: 1rem; margin: 4px 0 0; }
.co-chu-thich { margin: 0; }

/* Danh sách nước đi */
.co-nuoc { margin: 0; padding: 6px 10px 6px 42px; max-height: 220px; min-height: 60px; overflow-y: auto; border: 1px solid var(--vien); border-radius: var(--r-nho);
  font-variant-numeric: tabular-nums; background: #fff; }
.co-nuoc li { padding: 1px 0; }
.co-nuoc li::marker { color: var(--phu); }
.co-nuoc span { display: inline-block; min-width: 8.5em; }
.co-nuoc:empty::before { content: "Chưa có nước nào."; color: var(--phu); margin-left: -32px; }

/* Dải số (bài tập, cờ vây, caro) */
.co-so { list-style: none; margin: 0; padding: 0; display: grid; gap: 8px; grid-template-columns: repeat(auto-fit, minmax(92px, 1fr)); }
.co-so li { background: var(--bg); border: 1px solid var(--vien); border-radius: var(--r-nho); padding: 6px 10px; display: flex; flex-direction: column; }
.co-so b { font-size: 1.35rem; color: var(--c-dam); line-height: 1.2; }
.co-so span { font-size: .8125rem; color: var(--phu); }
.co-kq { padding: 10px 14px; border-radius: var(--r-nho); border: 1px solid #f3d49b; background: var(--nhan-nhat); }
.co-kq p { margin: 0 0 4px; }

/* Cờ tướng: số cột, ô được chọn, nước đi được, nước vừa đi */
.co-xq-cot { display: grid; grid-template-columns: repeat(9, 1fr); width: 100%; max-width: inherit; font-size: .8125rem; font-weight: 700; color: var(--phu); text-align: center; }
.co-ban-o:has(> .co-ban--tuong) .co-xq-cot { max-width: min(100%, 600px, max(300px, calc((100vh - 280px) * .9))); }
.co-p:fullscreen .co-ban-o:has(> .co-ban--tuong) .co-xq-cot { max-width: min(100%, calc((100vh - 90px) * .9)); }
#co-tuong-ban [data-square] { position: relative; }
#co-tuong-ban .co-xq-cuoi::before { content: ""; position: absolute; inset: 8%; border-radius: 50%; background: rgba(29, 79, 145, .22); }
#co-tuong-ban .co-xq-chon::before { content: ""; position: absolute; inset: 2%; border-radius: 50%; box-shadow: 0 0 0 3px #1d4f91; background: rgba(29, 79, 145, .18); z-index: 3; pointer-events: none; }
#co-tuong-ban .co-xq-dich::after { content: ""; position: absolute; left: 36%; top: 36%; width: 28%; height: 28%; border-radius: 50%; background: rgba(29, 79, 145, .55); z-index: 3; pointer-events: none; }
#co-tuong-ban .co-xq-an::after { content: ""; position: absolute; inset: 4%; border-radius: 50%; box-shadow: 0 0 0 3px #b3261e; z-index: 3; pointer-events: none; }
#co-tuong-ban img { position: relative; z-index: 2; }

/* Cờ vây */
.co-ban--vay canvas { display: block; }

/* Cờ caro */
.co-ban--caro { display: grid; grid-template-rows: repeat(15, 1fr); aspect-ratio: 1; border: 2px solid #6b4a1f; background: #f6e7c1; user-select: none; }
.co-caro-hang { display: grid; grid-template-columns: repeat(15, 1fr); }
.co-caro-o { display: grid; place-items: center; min-width: 0; min-height: 0; padding: 0; border: 0; border-right: 1px solid #cfb27a; border-bottom: 1px solid #cfb27a;
  background: transparent; font: inherit; font-weight: 800; font-size: clamp(.8rem, 2.6vw, 1.5rem); line-height: 1; cursor: pointer; color: var(--chu); }
.co-caro-hang .co-caro-o:last-child { border-right: 0; }
.co-caro-hang:last-child .co-caro-o { border-bottom: 0; }
.co-caro-o:hover { background: rgba(29, 79, 145, .1); }
.co-caro-o:focus-visible { outline: 3px solid var(--c); outline-offset: -3px; }
.co-caro-o--x { color: #b3261e; }
.co-caro-o--o { color: #093166; }
.co-caro-o--cuoi { background: rgba(240, 190, 88, .45); }
.co-caro-o--thang { background: #c8e6c9; }
.co-p:fullscreen .co-caro-o { font-size: clamp(.9rem, 3.2vh, 2rem); }

@media (max-width: 640px) {
  .co-tab [role="tab"] { padding: 8px 14px; }
  .co-p { padding: 8px; }
  .co-nuoc { max-height: 160px; }
}