:root {
  --navy: #0a2161; --blue: #0b7ac9; --ink: #1f2933; --muted: #5f6b76; --line: #e3e7eb; --bg: #f5f7f9;
  --card: #ffffff; --red: #b42318; --mine: #e8f2fb;
}
@media (prefers-color-scheme: dark) {
  :root {
    --navy: #9db8ff; --blue: #5cb3f0; --ink: #e6e9ec; --muted: #9aa5b1; --line: #2c3540; --bg: #12171d;
    --card: #1a2129; --red: #ff8a80; --mine: #1d3044;
  }
}
* { box-sizing: border-box; }
html, body { margin: 0; }
body { background: var(--bg); color: var(--ink); font: 15px/1.5 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif; }
.bar { display: flex; justify-content: space-between; align-items: center; gap: 12px; padding: 12px 16px; background: var(--card); border-bottom: 1px solid var(--line); }
.brand { font-weight: 700; color: var(--navy); }
.brand span { font-weight: 400; color: var(--muted); margin-left: 6px; }
#who { color: var(--muted); font-size: 13px; text-align: right; }
h1 { font-size: 20px; color: var(--navy); margin: 0 0 6px; }
.muted { color: var(--muted); }
.small { font-size: 13px; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 10px; padding: 24px; margin: 40px auto; }
.narrow { max-width: 420px; margin-left: 16px; margin-right: 16px; }
@media (min-width: 460px) { .narrow { margin-left: auto; margin-right: auto; } }
input, textarea { width: 100%; font: inherit; color: var(--ink); background: var(--bg); border: 1px solid var(--line); border-radius: 8px; padding: 10px 12px; }
input:focus, textarea:focus { outline: 2px solid var(--blue); outline-offset: 1px; }
button { font: inherit; font-weight: 600; color: #fff; background: var(--blue); border: 0; border-radius: 8px; padding: 10px 16px; cursor: pointer; }
button:disabled { opacity: .6; cursor: default; }
button.link { background: none; color: var(--muted); font-weight: 400; padding: 4px 6px; }
button.link:hover { color: var(--blue); }
#login { display: flex; flex-direction: column; gap: 10px; margin-top: 16px; }
.msg { min-height: 1.5em; margin: 12px 0 0; }
.msg.err { color: var(--red); }
.chat { max-width: 780px; margin: 0 auto; padding: 16px; display: flex; flex-direction: column; min-height: calc(100vh - 50px); }
.log { flex: 1; display: flex; flex-direction: column; gap: 12px; padding-bottom: 12px; }
.intro { padding: 8px 0 4px; }
.m { max-width: 92%; padding: 10px 14px; border-radius: 10px; border: 1px solid var(--line); background: var(--card); overflow-wrap: anywhere; }
.m.me { align-self: flex-end; background: var(--mine); border-color: transparent; white-space: pre-wrap; }
.m p { margin: 0 0 8px; }
.m p:last-child, .m ul:last-child { margin-bottom: 0; }
.m ul { margin: 0 0 8px; padding-left: 20px; }
.m.err { color: var(--red); }
.m.wait { color: var(--muted); font-style: italic; }
.pdf { display: inline-block; margin-top: 8px; margin-right: 8px; padding: 6px 12px; border: 1px solid var(--blue); border-radius: 8px; color: var(--blue); text-decoration: none; font-weight: 600; font-size: 14px; }
.ask { display: flex; gap: 8px; align-items: flex-end; position: sticky; bottom: 0; background: var(--bg); padding: 8px 0; }
.ask textarea { resize: vertical; min-height: 46px; }
.tools { display: flex; justify-content: flex-end; gap: 8px; }