:root{--bg: #0b0c10;--panel: #14161c;--line: #232733;--fg: #e7e9ee;--muted: #8b93a3;--accent: #5b8cff;font-family:ui-sans-serif,system-ui,-apple-system,Segoe UI,Roboto,sans-serif}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--fg)}.centered{min-height:100vh;display:flex;align-items:center;justify-content:center}.muted{color:var(--muted)}.signin-card{text-align:center;padding:2.5rem 3rem;border:1px solid var(--line);border-radius:16px;background:var(--panel)}.signin-card h1{margin:0 0 .25rem;font-size:1.6rem}.signin-card p{margin:0 0 1.5rem}button.primary,.composer button{background:var(--accent);color:#fff;border:none;border-radius:10px;padding:.6rem 1.2rem;font-size:.95rem;cursor:pointer}button:disabled{opacity:.5;cursor:default}.app{max-width:760px;margin:0 auto;min-height:100vh;display:flex;flex-direction:column}.bar{display:flex;align-items:center;gap:.75rem;padding:.9rem 1.1rem;border-bottom:1px solid var(--line)}.bar .brand{font-weight:600}.bar .who{margin-left:auto;font-size:.85rem;color:var(--muted)}.thread{flex:1;overflow-y:auto;padding:1.25rem;display:flex;flex-direction:column;gap:.75rem}.msg{max-width:80%;padding:.6rem .85rem;border-radius:12px;white-space:pre-wrap;line-height:1.4}.msg.user{align-self:flex-end;background:var(--accent);color:#fff}.msg.assistant{align-self:flex-start;background:var(--panel);border:1px solid var(--line)}.composer{display:flex;gap:.6rem;padding:1rem;border-top:1px solid var(--line)}.composer input{flex:1;background:var(--panel);border:1px solid var(--line);border-radius:10px;color:var(--fg);padding:.6rem .85rem;font-size:.95rem}