/* AI শিক্ষক (js/v2ai.js): the "AI দিয়ে বুঝুন" button, its answer sheet and the answer box of ai.php.
   Self-contained on purpose (own --ai-* colours, no generic class names), so it behaves the same inside exam.php (examsv2.css)
   and ai.php (v2theme.css). */
:root{--ai-brand:#4F46E5;--ai-brand-soft:#EEF0FF;--ai-line:#E6E8F0;--ai-muted:#667085;--ai-bg:#F5F6FB;--ai-text:#14162B;--ai-rose:#E11D48;--ai-rose-soft:#FFE8ED;--ai-amber:#D97706;--ai-amber-soft:#FFF0D4;--ai-green:#15803D}
.aibtn{display:inline-flex;align-items:center;gap:6px;padding:6px 14px;border-radius:999px;font-size:13px;font-weight:700;color:#fff;background:linear-gradient(135deg,#4F46E5,#7C3AED);box-shadow:0 4px 12px rgba(79,70,229,.25);transition:.15s}
.aibtn:hover{transform:translateY(-1px);box-shadow:0 6px 16px rgba(79,70,229,.34)}
.ai-q{background:var(--ai-bg);border-radius:11px;padding:12px 14px;margin-bottom:12px;font-size:14px;line-height:1.7;max-height:26vh;overflow:auto}
.ai-q .opt{cursor:default;margin:6px 0 0;padding:6px 10px;font-size:13px}.ai-q .ans-line{display:block;margin-top:8px;color:var(--ai-green);font-weight:700}
.ai-lang{display:flex;gap:6px;margin-bottom:12px;flex-wrap:wrap}
.ai-pill{padding:6px 14px;border-radius:999px;font-size:13px;font-weight:700;color:var(--ai-muted);background:var(--ai-bg);border:1.5px solid var(--ai-line)}
.ai-pill.on{color:#fff;background:var(--ai-brand);border-color:var(--ai-brand)}
.ai-out{font-size:15px;line-height:1.8;color:var(--ai-text);min-height:60px;overflow-wrap:anywhere}
.ai-out h3{font-size:15.5px;font-weight:800;margin:14px 0 6px;color:var(--ai-brand)}.ai-out h3:first-child{margin-top:0}
.ai-out p{margin:0 0 8px}.ai-out ul,.ai-out ol{margin:0 0 8px;padding-left:22px}.ai-out li{margin-bottom:4px}
.ai-out blockquote{margin:0 0 10px;padding:8px 12px;border-left:4px solid var(--ai-amber);background:var(--ai-amber-soft);border-radius:8px;font-size:13.5px}
.ai-out .mathblock{margin:6px 0;overflow-x:auto;text-align:center}
.ai-skel i{display:block;height:12px;border-radius:6px;margin:10px 0;background:linear-gradient(90deg,#EDEFF6,#F7F8FC,#EDEFF6);background-size:200% 100%;animation:aiskel 1.2s infinite}
.ai-skel i:nth-child(2){width:80%}.ai-skel i:nth-child(3){width:55%}
@keyframes aiskel{from{background-position:200% 0}to{background-position:-200% 0}}
.ai-wait{font-size:13px;color:var(--ai-muted);font-weight:600}
.ai-err{background:var(--ai-rose-soft);color:var(--ai-rose);border-radius:11px;padding:12px 14px;font-weight:600;line-height:1.6}.ai-err a{color:var(--ai-brand);text-decoration:underline}
.ai-meta{font-size:12.5px;color:var(--ai-muted);font-weight:600;margin-top:10px}
.ai-act{display:flex;gap:8px;flex-wrap:wrap;margin-top:12px}.ai-act[hidden],.ai-reasons[hidden]{display:none}
.ai-act button,.ai-reasons button{padding:6px 14px;border-radius:999px;font-size:13px;font-weight:700;color:var(--ai-muted);background:var(--ai-bg);border:1.5px solid var(--ai-line)}
.ai-act button.on{color:var(--ai-brand);border-color:var(--ai-brand);background:var(--ai-brand-soft)}
.ai-reasons{display:flex;gap:6px;flex-wrap:wrap;margin-top:8px}
.ai-note{font-size:12px;color:var(--ai-muted);margin:12px 0 0;line-height:1.6}
@media(prefers-reduced-motion:reduce){.ai-skel i{animation:none}}

/* the answer sheet (#aimodal) */
.ai-ovl{position:fixed;inset:0;background:rgba(15,16,40,.5);z-index:2147483000;display:flex;align-items:center;justify-content:center;padding:16px;backdrop-filter:blur(4px)}
.ai-ovl[hidden]{display:none}
.ai-card{background:#fff;border-radius:20px;max-width:580px;width:100%;max-height:92vh;overflow:auto;padding:22px;box-shadow:0 24px 60px rgba(0,0,0,.28);font-family:inherit;color:var(--ai-text);box-sizing:border-box}
.ai-head{display:flex;align-items:center;justify-content:space-between;font-size:16px;margin-bottom:12px}
.ai-close{width:34px;height:34px;border-radius:10px;font-size:15px;color:var(--ai-muted);background:var(--ai-bg);border:0;cursor:pointer}
.ai-close:hover{background:var(--ai-rose-soft);color:var(--ai-rose)}
.ai-q[hidden]{display:none}
.aibtn{border:0;cursor:pointer;font-family:inherit}
.aibtn[hidden]{display:none}