:root{font-family:system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif;line-height:1.4;font-weight:400;color:#0f172a;background-color:#e5e7eb;font-synthesis:none;text-rendering:optimizeLegibility;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}*,*:before,*:after{box-sizing:border-box}body{margin:0;min-width:320px;min-height:100vh;background:radial-gradient(circle at top,#fff,#e5e7eb)}#root{min-height:100vh}.app-root{min-height:100vh;display:flex;justify-content:center;align-items:stretch;padding:16px}.chat-page{background:#fff;color:#111827;border-radius:20px;box-shadow:0 18px 40px #0f172a1f,0 0 0 1px #0f172a0f;width:100%;max-width:480px;display:flex;flex-direction:column;overflow:hidden}.chat-header{padding:14px 16px 10px;border-bottom:1px solid #e5e7eb;background:linear-gradient(135deg,#eff6ff,#fff);display:flex;align-items:center;justify-content:space-between;gap:8px}.chat-header-main{display:flex;flex-direction:column}.chat-header-title{font-size:19px;font-weight:600;color:#111827}.chat-header-subtitle{font-size:12px;color:#6b7280;margin-top:2px}.chat-header-clear-btn{border:none;border-radius:999px;padding:6px 10px;font-size:11px;font-weight:500;cursor:pointer;background:#f3f4f6;color:#374151;display:inline-flex;align-items:center;justify-content:center;transition:background-color .15s ease,transform .05s ease,box-shadow .1s ease}.chat-header-clear-btn:hover{background:#e5e7eb}.chat-header-clear-btn:active{transform:translateY(1px);box-shadow:none}.chat-main{flex:1;display:flex;flex-direction:column;overflow:hidden;padding:8px 8px 0}.chat-empty{text-align:center;font-size:14px;color:#6b7280;padding:12px 16px}.chat-empty p{margin:4px 0}.chat-messages{flex:1;overflow-y:auto;padding:4px 4px 8px;display:flex;flex-direction:column;gap:6px}.message-row{display:flex}.message-row--user{justify-content:flex-end}.message-row--assistant{justify-content:flex-start}.message-bubble-wrapper{max-width:80%}.message-bubble{border-radius:16px;padding:8px 10px 6px;font-size:14px;line-height:1.4;position:relative;background:#f9fafb;border:1px solid #e5e7eb}.message-bubble--user{background:linear-gradient(135deg,#2563eb,#1d4ed8);color:#eff6ff;border-bottom-right-radius:4px}.message-bubble--assistant{background:#f9fafb;border:1px solid #e5e7eb;border-bottom-left-radius:4px}.message-bubble--assistant-teacher{background:#fefce8;border:1px dashed #facc15;border-bottom-left-radius:4px}.message-text{margin:0 0 2px;white-space:pre-wrap;word-wrap:break-word}.message-label{display:inline-block;margin-right:6px;padding:1px 6px;border-radius:999px;font-size:10px;text-transform:uppercase;letter-spacing:.03em;background:#eab30826;color:#92400e}.message-time{font-size:11px;opacity:.7;display:block;text-align:right}.message-meta-row{display:flex;align-items:center;justify-content:space-between;gap:6px}.message-tts-button{border:none;border-radius:999px;padding:2px 8px;font-size:10px;cursor:pointer;background:#2563ebd9;color:#e5e7eb;display:inline-flex;align-items:center;justify-content:center}.message-tts-button:disabled{opacity:.5;cursor:default}.message-tts-loader{display:inline-block;width:10px;height:10px;border-radius:999px;border:2px solid rgba(148,163,184,.4);border-top-color:#e5e7eb;animation:chat-spin .6s linear infinite}.chat-footer{padding:6px 8px 10px;border-top:1px solid #e5e7eb;background:#f9fafb}.chat-error{background:#f8717114;border:1px solid rgba(248,113,113,.35);color:#b91c1c;border-radius:10px;padding:6px 8px;font-size:12px;margin-bottom:6px;cursor:pointer}.chat-input-row{display:flex;align-items:center;gap:6px}.chat-input{flex:1;border-radius:999px;padding:8px 12px;border:1px solid #d1d5db;background:#fff;color:#111827;font-size:14px}.chat-input::placeholder{color:#9ca3af}.chat-send-btn,.chat-mic-btn{border-radius:999px;border:none;font-size:12px;font-weight:500;cursor:pointer;font-family:inherit;transition:background-color .15s ease,transform .05s ease,box-shadow .1s ease}.chat-icon-btn{width:36px;height:36px;padding:0;display:inline-flex;align-items:center;justify-content:center}.chat-send-btn{background:#2563eb;color:#f9fafb;box-shadow:0 6px 18px #2563eb59}.chat-send-btn:disabled{opacity:.4;cursor:default}.chat-mic-btn{background:#10b981;color:#ecfdf5}.chat-mic-btn--active{background:#ef4444}.chat-send-btn:not(:disabled):active,.chat-mic-btn:active{transform:translateY(1px);box-shadow:0 0 0 0 transparent}.chat-stop-btn{flex:1;border-radius:999px;border:none;padding:10px 14px;font-size:13px;font-weight:500;cursor:pointer;font-family:inherit;background:#ef4444;color:#fef2f2;display:inline-flex;align-items:center;justify-content:center;gap:6px;box-shadow:0 6px 18px #ef444459;transition:background-color .15s ease,transform .05s ease,box-shadow .1s ease}.chat-stop-btn:active{transform:translateY(1px);box-shadow:none}.chat-stop-icon{font-size:14px}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}.chat-status-row{margin-top:4px;min-height:18px}.chat-status-text{font-size:11px;color:#6b7280}.chat-status-spinner{display:inline-block;width:10px;height:10px;margin-right:6px;border-radius:999px;border:2px solid rgba(148,163,184,.4);border-top-color:#4b5563;animation:chat-spin .6s linear infinite}.chat-status-dot{display:inline-block;width:8px;height:8px;margin-right:6px;border-radius:999px;background:#f97316;box-shadow:0 0 0 4px #f8b16140}@keyframes chat-spin{0%{transform:rotate(0)}to{transform:rotate(360deg)}}@media(max-width:600px){.app-root{padding:12px}.chat-page{border-radius:18px}}