:root{font-family:Segoe UI,PingFang SC,Microsoft YaHei,sans-serif;color:#16212f;background:radial-gradient(circle at top left,rgba(255,197,117,.4),transparent 32%),linear-gradient(145deg,#f7f1e8,#dce9f8);line-height:1.5;font-weight:400;color-scheme:light}*{box-sizing:border-box}body{margin:0;min-width:320px;min-height:100vh}button,textarea{font:inherit}.page-shell{min-height:100vh;display:grid;place-items:center;padding:24px}.chat-card{width:min(960px,100%);min-height:80vh;display:grid;grid-template-rows:auto 1fr auto auto;gap:18px;padding:28px;border:1px solid rgba(255,255,255,.55);border-radius:28px;background:#fffaf4b8;box-shadow:0 24px 60px #36476329;-webkit-backdrop-filter:blur(18px);backdrop-filter:blur(18px)}.hero{display:grid;gap:10px}.hero h1,.hero p{margin:0}.eyebrow{color:#8b5e34;font-size:.82rem;line-height:1.4;letter-spacing:.12em;text-transform:uppercase}.hero h1{font-size:clamp(2rem,5vw,3.4rem);line-height:1.16}.subtitle{max-width:640px;color:#4d5b6b;line-height:1.65}.hero ::selection{background:#1f6feb38;color:inherit}.chat-body{overflow-y:auto;padding-right:8px}.message-row{display:grid;gap:8px;margin-bottom:18px}.message-row.user{justify-items:end}.message-meta{font-size:.9rem;color:#5e6a78}.message-bubble{max-width:min(78%,720px);padding:14px 16px;border-radius:20px;white-space:pre-wrap;box-shadow:0 8px 20px #29344814}.message-row.model .message-bubble{background:#fffefc;border-top-left-radius:8px}.message-row.user .message-bubble{background:linear-gradient(135deg,#1f6feb,#1c89d6);color:#fff;border-top-right-radius:8px}.typing{opacity:.78}.error-banner{margin:0;padding:12px 14px;border-radius:16px;background:#c534341f;color:#8c1d1d}.composer{display:grid;gap:12px}.composer-input{width:100%;resize:none;padding:16px 18px;border:1px solid rgba(25,48,78,.12);border-radius:20px;background:#ffffffd1;outline:none;transition:border-color .2s ease,box-shadow .2s ease}.composer-input:focus{border-color:#1f6febb3;box-shadow:0 0 0 4px #1f6feb1f}.send-button{justify-self:end;min-width:120px;border:none;border-radius:999px;padding:12px 20px;background:#16212f;color:#fff;cursor:pointer;transition:transform .18s ease,opacity .18s ease}.send-button:hover:enabled{transform:translateY(-1px)}.send-button:disabled{cursor:not-allowed;opacity:.58}@media(max-width:720px){.page-shell{padding:14px}.chat-card{min-height:100vh;padding:18px;border-radius:0}.message-bubble{max-width:92%}}