:root {
  --bg: #faf7f2;
  --panel: #ffffff;
  --ink: #1d1a17;
  --muted: #6f675e;
  --line: #e6dfd4;
  --accent: #b4441f;
  --accent-ink: #ffffff;
  --soft: #f3ece1;
  --radius: 10px;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #15130f;
    --panel: #1e1b16;
    --ink: #f1ebe0;
    --muted: #a39a8c;
    --line: #34302a;
    --accent: #e0714a;
    --accent-ink: #15130f;
    --soft: #27231d;
  }
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 15px/1.55 Inter, system-ui, sans-serif; }
h1, h2, h3 { font-family: Fraunces, Georgia, serif; font-weight: 600; letter-spacing: -0.01em; margin: 0; }
button { font: inherit; cursor: pointer; }
input, textarea { font: inherit; color: inherit; background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: 10px 12px; width: 100%; }
textarea { resize: vertical; min-height: 90px; }
input:focus, textarea:focus, button:focus-visible { outline: 2px solid var(--accent); outline-offset: 1px; }
label { display: block; font-weight: 500; margin: 14px 0 4px; }
.hint { color: var(--muted); font-size: 13px; margin: 2px 0 0; }
.btn { background: var(--accent); color: var(--accent-ink); border: 0; border-radius: var(--radius); padding: 10px 16px; font-weight: 600; }
.btn:disabled { opacity: .55; cursor: wait; }
.btn.ghost { background: transparent; color: var(--ink); border: 1px solid var(--line); }
.btn.small { padding: 5px 10px; font-size: 13px; }
.error { color: #b3261e; margin: 10px 0 0; }

.auth { max-width: 380px; margin: 12vh auto; padding: 0 16px; }
.auth h1 { font-size: 32px; margin-bottom: 4px; }
.auth form { margin-top: 20px; }
.auth .btn { width: 100%; margin-top: 18px; }
.auth .switch { background: none; border: 0; color: var(--accent); padding: 0; margin-top: 14px; }

.shell { display: grid; grid-template-columns: 220px 1fr; min-height: 100vh; }
nav { border-right: 1px solid var(--line); padding: 20px 12px; background: var(--panel); position: sticky; top: 0; height: 100vh; overflow-y: auto; }
nav h1 { font-size: 20px; padding: 0 10px 14px; }
nav button.tab { display: block; width: 100%; text-align: left; background: none; border: 0; padding: 9px 10px; border-radius: 8px; color: var(--ink); }
nav button.tab:hover { background: var(--soft); }
nav button.tab.on { background: var(--soft); font-weight: 600; box-shadow: inset 3px 0 var(--accent); }
nav .sep { height: 1px; background: var(--line); margin: 10px 4px; }
nav .foot { margin-top: 16px; padding: 0 10px; color: var(--muted); font-size: 13px; }
nav .foot button { background: none; border: 0; color: var(--accent); padding: 0; }

main { padding: 28px clamp(16px, 4vw, 48px) 40px; max-width: 920px; width: 100%; }
main > header { margin-bottom: 18px; }
main > header h2 { font-size: 28px; }
main > header p { margin: 4px 0 0; color: var(--muted); }

.starters { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 16px; }
.chip { background: var(--soft); border: 1px solid var(--line); color: var(--ink); border-radius: 999px; padding: 6px 12px; font-size: 13px; }
.chip:hover { border-color: var(--accent); }

.msgs { display: flex; flex-direction: column; gap: 14px; margin-bottom: 18px; }
.msg { border: 1px solid var(--line); border-radius: var(--radius); padding: 12px 16px; background: var(--panel); }
.msg.user { background: var(--soft); align-self: flex-end; max-width: 85%; white-space: pre-wrap; }
.msg .actions { margin-top: 10px; display: flex; gap: 8px; }
.md > :first-child { margin-top: 0; }
.md > :last-child { margin-bottom: 0; }
.md table { border-collapse: collapse; display: block; overflow-x: auto; font-size: 14px; }
.md th, .md td { border: 1px solid var(--line); padding: 6px 10px; text-align: left; vertical-align: top; }
.md th { background: var(--soft); }
.md pre { background: var(--soft); padding: 10px; border-radius: 8px; overflow-x: auto; }
.md h1, .md h2, .md h3 { font-size: 19px; margin: 16px 0 6px; }

.composer { position: sticky; bottom: 0; background: var(--bg); padding: 10px 0 4px; display: flex; gap: 10px; align-items: flex-end; }
.composer textarea { min-height: 52px; max-height: 200px; }
.thinking { color: var(--muted); font-style: italic; }

.card { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: 16px 18px; margin-bottom: 14px; }
.card h3 { font-size: 18px; margin-bottom: 8px; }
.row { display: flex; gap: 10px; flex-wrap: wrap; align-items: center; margin-top: 14px; }

@media (max-width: 760px) {
  .shell { grid-template-columns: 1fr; }
  nav { position: static; height: auto; display: flex; flex-wrap: wrap; gap: 4px; border-right: 0; border-bottom: 1px solid var(--line); padding: 10px; }
  nav h1 { width: 100%; padding: 0 6px 6px; }
  nav button.tab { width: auto; }
  nav .sep { display: none; }
  nav .foot { width: 100%; margin: 6px 0 0; }
}