.student-chat-card{height:calc(100dvh - 170px);min-height:520px;background:#fff;border:1px solid var(--line);border-radius:24px;overflow:hidden;display:grid;grid-template-rows:auto auto minmax(0,1fr) auto auto;box-shadow:0 14px 36px rgba(62,43,95,.08)}.student-chat-head{display:flex;align-items:center;gap:12px;padding:15px 16px;border-bottom:1px solid var(--line);background:linear-gradient(180deg,#fff,#fbf9ff)}.student-chat-avatar{width:46px;height:46px;flex:0 0 46px;border-radius:50%;display:grid;place-items:center;background:linear-gradient(135deg,var(--p),var(--p2));color:#fff;font-weight:900;font-size:20px}.student-chat-head h2{font-size:16px;margin:0 0 3px}.student-chat-head p{font-size:11px;color:var(--muted);margin:0}.student-chat-live{margin-left:auto;font-size:10px;color:#36a268;background:#effaf3;padding:6px 8px;border-radius:999px;font-weight:800}.student-chat-history{overflow:auto;padding:18px 13px 12px;display:flex;flex-direction:column;gap:10px;scroll-behavior:smooth}.student-chat-bubble{max-width:82%;padding:10px 12px;border-radius:18px;line-height:1.42;box-shadow:0 3px 10px rgba(44,32,67,.04)}.student-chat-bubble.mine{align-self:flex-end;background:linear-gradient(135deg,#7048d8,#8c6ae4);color:#fff;border-bottom-right-radius:6px}.student-chat-bubble.teacher{align-self:flex-start;background:#f5f2fa;color:var(--ink);border:1px solid #ebe5f4;border-bottom-left-radius:6px}.student-chat-meta{display:flex;align-items:center;gap:8px;margin-bottom:4px;font-size:9px;opacity:.72}.student-chat-meta b{font-size:10px}.student-chat-text{white-space:pre-wrap;overflow-wrap:anywhere;font-size:14px}.student-chat-read{display:block;text-align:right;font-size:9px;margin-top:4px;opacity:.65}.student-chat-empty{margin:auto;text-align:center;display:grid;gap:5px;color:var(--muted);padding:28px}.student-chat-empty b{color:var(--ink)}.student-chat-compose{display:flex;align-items:flex-end;gap:8px;padding:10px 11px;background:#fff;border-top:1px solid var(--line)}.student-chat-compose textarea{resize:none;flex:1;min-height:46px;max-height:120px;border:1px solid #ddd5ed;background:#faf9fc;border-radius:17px;padding:12px 14px;outline:none;line-height:1.35}.student-chat-compose textarea:focus{border-color:var(--p);box-shadow:0 0 0 3px rgba(112,72,216,.1);background:#fff}.student-chat-compose button{width:46px;height:46px;flex:0 0 46px;border:0;border-radius:50%;background:var(--p);color:#fff;font-size:19px;font-weight:900}.student-chat-compose button:disabled{opacity:.55}.student-chat-state{min-height:0;padding:0 14px 8px;color:var(--muted);font-size:10px}.nav-item{position:relative}.chat-nav-badge{position:absolute;top:4px;left:calc(50% + 8px);min-width:17px;height:17px;padding:0 4px;border-radius:999px;background:#e84d67;color:#fff;font-style:normal;font-size:9px;font-weight:900;display:grid;place-items:center;border:2px solid #fff}.chat-nav-badge[hidden]{display:none}@media(min-width:700px){.student-chat-card{height:min(690px,calc(100dvh - 190px));min-height:560px}.student-chat-history{padding:22px}.student-chat-bubble{max-width:68%}}
.student-chat-photo{display:block;margin-top:8px}.student-chat-photo img{display:block;max-width:100%;max-height:360px;object-fit:contain;border-radius:13px;background:rgba(0,0,0,.05)}.student-chat-file{display:inline-flex;margin-top:8px;padding:7px 9px;border-radius:10px;background:rgba(255,255,255,.18);color:inherit;text-decoration:none;font-size:11px}

.student-chat-attach{width:42px;height:42px;flex:0 0 42px;border:1px solid var(--line);border-radius:50%;display:grid;place-items:center;cursor:pointer;background:#faf9fc}.student-chat-file-name{padding:0 14px 6px;font-size:10px;color:var(--muted);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}

.student-chat-compose.drag-over{outline:2px dashed #7450e8;outline-offset:3px;background:#f7f3ff}

.student-helper{padding:13px 16px 11px;border-bottom:1px solid var(--line);background:#fcfaff}.student-helper-title{display:flex;align-items:baseline;gap:8px;flex-wrap:wrap}.student-helper-title b{font-size:13px;color:var(--ink)}.student-helper-title small{font-size:10px;color:var(--muted)}.student-helper-topics{display:flex;gap:7px;overflow-x:auto;padding:9px 0 3px;scrollbar-width:thin}.student-helper-topics button{flex:0 0 auto;border:1px solid #ded5f3;background:#fff;color:#5e3aaf;border-radius:999px;padding:7px 10px;font-size:11px;font-weight:700;cursor:pointer}.student-helper-topics button:focus-visible{outline:2px solid var(--p);outline-offset:2px}.student-helper p{margin:6px 0 0;font-size:11px;line-height:1.4;color:var(--muted)}@media(max-width:700px){.student-helper{padding:10px 12px}.student-helper-title small{display:block}}