:root{font-family:"Aptos","Segoe UI","Microsoft YaHei",system-ui,sans-serif;color:#17314c;background:#dce9ef;font-synthesis:none;--blue:#1c78e8;--cyan:#30c9e8;--ink:#17314c;--muted:#718398;--line:#e3ebf1}
*{box-sizing:border-box}html,body{width:100%;height:100%;margin:0;overflow:hidden}button{font:inherit}button:focus-visible{outline:4px solid #6bd9ec;outline-offset:5px}[hidden]{display:none!important}
.classroom{width:100%;height:100dvh;min-height:560px;display:grid;grid-template-columns:minmax(330px,43%) minmax(470px,57%);background:#fff}
.robot-stage{position:relative;overflow:hidden;background:#ececec}
.robot-stage:before{content:"";position:absolute;inset:auto -15% -24% -15%;height:42%;border-radius:50%;background:#dedede;filter:blur(1px)}
.intro{position:absolute;z-index:3;top:clamp(28px,4.5vh,64px);left:clamp(28px,4vw,70px)}
.eyebrow{display:block;color:#6f8795;font-size:clamp(11px,1vw,15px);font-weight:700;letter-spacing:.22em;margin-bottom:11px}
h1{margin:0;font-size:clamp(30px,3vw,52px);line-height:1.12;font-weight:720;letter-spacing:-.025em;color:#17314c}h1 span{color:var(--cyan)}
.robot-media{position:absolute;inset:12% 6% 9%;display:grid;place-items:center}.robot-media img,.robot-media video{position:absolute;width:100%;height:100%;object-fit:contain;object-position:center center}.robot-media video{opacity:0}.robot-media.speaking video{opacity:1}.robot-media.speaking img{opacity:0}
.robot-state{position:absolute;z-index:3;left:50%;bottom:clamp(18px,3vh,36px);transform:translateX(-50%);display:flex;align-items:center;gap:12px;max-width:88%;width:max-content;padding:11px 18px;border:1px solid #d7e3e7;border-radius:999px;background:#fffffff0;box-shadow:0 8px 24px #4f788514;color:#5f7685;font-size:clamp(12px,1vw,15px);white-space:nowrap}
.voice-bars{display:flex;align-items:center;gap:3px;height:18px}.voice-bars i{display:block;width:3px;height:5px;border-radius:3px;background:var(--cyan)}.voice-bars.active i{animation:wave .65s ease-in-out infinite alternate}.voice-bars i:nth-child(2){animation-delay:.12s}.voice-bars i:nth-child(3){animation-delay:.28s}.voice-bars i:nth-child(4){animation-delay:.08s}.voice-bars i:nth-child(5){animation-delay:.2s}@keyframes wave{to{height:18px}}
.conversation{min-width:0;min-height:0;display:flex;flex-direction:column;background:linear-gradient(160deg,#fff 38%,#f6fbfd 100%);padding:clamp(30px,5vh,68px) clamp(30px,5vw,82px) clamp(22px,3vh,42px)}
.messages{flex:1;min-height:0;overflow:auto;padding:4px 8px 10px 0;scrollbar-width:thin;scrollbar-color:#cfdae2 transparent;overscroll-behavior:contain}
.message{display:flex;align-items:flex-start;gap:12px;margin:0 0 clamp(20px,3.4vh,38px)}.message-avatar{flex:0 0 42px;width:42px;height:42px;border-radius:14px;overflow:hidden;display:grid;place-items:center;background:#e7f7fb;color:#1b7795;font-size:13px;font-weight:750}.message-avatar img{width:100%;height:100%;object-fit:cover;object-position:center 18%;transform:scale(1.55);transform-origin:center 18%}.message-body{max-width:min(86%,720px)}.message-label{margin:0 0 8px;color:#8a9aaa;font-size:13px;font-weight:650;letter-spacing:.04em}.message-bubble{padding:16px 20px;border-radius:5px 20px 20px;background:#edf4f7;color:var(--ink);font-size:clamp(17px,1.55vw,25px);line-height:1.55;box-shadow:0 7px 22px #3151660a;white-space:pre-wrap;overflow-wrap:anywhere}.message.user{flex-direction:row-reverse}.message.user .message-body{display:flex;flex-direction:column;align-items:flex-end}.message.user .message-bubble{background:linear-gradient(135deg,#287ce7,#1e65d0);color:#fff;border-radius:20px 5px 20px 20px}.message.user .message-avatar{background:#eaf0f4;color:#607687}
.controls{flex:0 0 auto;display:flex;flex-direction:column;align-items:center;padding-top:13px;border-top:1px solid var(--line)}.mic{width:clamp(66px,6vw,84px);height:clamp(66px,6vw,84px);border:0;border-radius:50%;display:grid;place-items:center;background:linear-gradient(145deg,#35cae8,#1974e4);color:#fff;box-shadow:0 12px 30px #1974e43d;cursor:pointer;transition:transform .18s,box-shadow .18s}.mic:hover{transform:translateY(-2px);box-shadow:0 16px 36px #1974e44b}.mic:active{transform:translateY(1px) scale(.98)}.mic:disabled{cursor:default;opacity:.62;transform:none}.mic svg{width:34px;height:34px;fill:none;stroke:currentColor;stroke-width:1.8;stroke-linecap:round;stroke-linejoin:round}.mic.recording{background:linear-gradient(145deg,#ff7f73,#ef4f5d);animation:pulse 1.2s ease-out infinite}@keyframes pulse{50%{box-shadow:0 0 0 12px #ef4f5d1d,0 13px 30px #ef4f5d38}}
#micHint{margin:9px 0 0;color:#8293a1;font-size:13px}.notice{max-width:540px;margin:0 0 11px;padding:9px 14px;border-radius:10px;background:#fff4de;color:#8a6122;font-size:13px;line-height:1.45;text-align:center}
@media(max-width:900px){.classroom{grid-template-columns:40% 60%}.conversation{padding-left:28px;padding-right:28px}.robot-media{inset:17% 0 11%}.intro{left:24px}.message-body{max-width:88%}}
@media(max-width:650px){html,body{overflow:auto}.classroom{height:auto;min-height:100dvh;display:flex;flex-direction:column}.robot-stage{height:42vh;min-height:285px}.robot-media{inset:4% 2% 3%;left:38%}.intro{top:25px;left:24px;max-width:46%}.eyebrow{line-height:1.5}.robot-state{left:24px;bottom:25px;transform:none;white-space:normal;max-width:43%;padding:0;border:0;background:transparent;box-shadow:none}.conversation{height:58vh;min-height:430px;padding:26px 20px 18px}.message-avatar{width:34px;height:34px;flex-basis:34px;border-radius:11px}.message-bubble{font-size:17px;padding:13px 16px}.mic{width:64px;height:64px}.mic svg{width:29px;height:29px}}
@media(prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important}}