:root {
  --bg: #f4f6f8; --card: #ffffff; --ink: #14202b; --muted: #5b6b7a; --line: #dde3e9;
  --brand: #0b5cad; --brand-ink: #ffffff; --brand-soft: #e6f0fa; --ok: #1b7f4a; --warn: #a15c00; --bad: #b42318;
  --radius: 14px; --shadow: 0 1px 2px rgba(16,24,40,.06), 0 1px 3px rgba(16,24,40,.08);
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0f1419; --card: #182029; --ink: #e8edf2; --muted: #9aa8b5; --line: #2a3542;
    --brand: #5aa2ec; --brand-ink: #0b1620; --brand-soft: #1b2b3c; --ok: #4cc38a; --warn: #f0b35a; --bad: #f97066;
  }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0; background: var(--bg); color: var(--ink);
  font: 16px/1.6 "Noto Sans Thai", system-ui, -apple-system, "Segoe UI", sans-serif;
}
a { color: var(--brand); }
.wrap { max-width: 760px; margin: 0 auto; padding: 0 16px 48px; }
header.top {
  position: sticky; top: 0; z-index: 10; background: var(--card); border-bottom: 1px solid var(--line);
}
header.top .wrap { display: flex; align-items: center; gap: 12px; padding-top: 10px; padding-bottom: 10px; }
.logo { font-weight: 700; font-size: 1.05rem; letter-spacing: .2px; text-decoration: none; color: var(--ink); }
.logo b { color: var(--brand); }
.spacer { flex: 1; }
.who { font-size: .85rem; color: var(--muted); max-width: 45vw; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow); padding: 20px; margin-top: 16px; }
.card h1, .card h2 { margin: 0 0 6px; line-height: 1.35; }
.card h1 { font-size: 1.35rem; } .card h2 { font-size: 1.1rem; }
.muted { color: var(--muted); font-size: .92rem; }
.btn {
  appearance: none; border: 0; border-radius: 10px; padding: 12px 18px; font: inherit; font-weight: 600;
  background: var(--brand); color: var(--brand-ink); cursor: pointer; min-height: 46px;
}
.btn.secondary { background: var(--brand-soft); color: var(--brand); }
.btn.ghost { background: transparent; color: var(--muted); padding: 8px 10px; min-height: 0; font-weight: 500; }
.btn:disabled { opacity: .55; cursor: progress; }
.btn.block { width: 100%; }
.tabs { display: flex; gap: 6px; margin-top: 16px; overflow-x: auto; }
.tab { flex: 1 0 auto; border: 1px solid var(--line); background: var(--card); color: var(--ink); border-radius: 999px; padding: 10px 16px; font: inherit; cursor: pointer; }
.tab[aria-selected="true"] { background: var(--brand); color: var(--brand-ink); border-color: var(--brand); }
.grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px 14px; }
.grid .full { grid-column: 1 / -1; }
@media (max-width: 520px) { .grid { grid-template-columns: 1fr; } }
label { display: block; font-size: .9rem; font-weight: 600; margin-bottom: 4px; }
input, select, textarea {
  width: 100%; font: inherit; color: var(--ink); background: var(--bg); border: 1px solid var(--line);
  border-radius: 10px; padding: 11px 12px; min-height: 46px;
}
textarea { min-height: 140px; resize: vertical; }
input:focus, select:focus, textarea:focus { outline: 2px solid var(--brand); outline-offset: 1px; }
.hint { font-size: .8rem; color: var(--muted); margin-top: 3px; }
.result { border-left: 4px solid var(--brand); }
.big { font-size: 2rem; font-weight: 700; color: var(--brand); line-height: 1.2; margin: 4px 0 8px; font-variant-numeric: tabular-nums; }
.steps { margin: 8px 0 0; padding-left: 20px; font-size: .9rem; color: var(--muted); }
.steps li { margin: 3px 0; word-break: break-word; }
.row { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 14px; }
.row .btn { flex: 1 1 180px; }
.err { color: var(--bad); font-size: .92rem; margin-top: 10px; }
.notice { background: var(--brand-soft); border-radius: 10px; padding: 12px 14px; font-size: .9rem; margin-top: 12px; }
.badge { display: inline-block; font-size: .78rem; padding: 2px 10px; border-radius: 999px; background: var(--brand-soft); color: var(--brand); font-weight: 600; }
.badge.ok { color: var(--ok); } .badge.warn { color: var(--warn); } .badge.bad { color: var(--bad); }
.links { display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: 8px; margin-top: 10px; }
.links a { display: block; padding: 10px 12px; border: 1px solid var(--line); border-radius: 10px; text-decoration: none; color: var(--ink); background: var(--bg); font-size: .9rem; }
table { width: 100%; border-collapse: collapse; font-size: .85rem; }
th, td { text-align: left; padding: 8px 6px; border-bottom: 1px solid var(--line); vertical-align: top; }
.table-scroll { overflow-x: auto; }
[hidden] { display: none !important; }
footer { margin-top: 28px; font-size: .8rem; color: var(--muted); text-align: center; }

.chat { display: flex; flex-direction: column; gap: 10px; max-height: 60vh; overflow-y: auto; padding: 4px 2px; }
.msg { padding: 10px 14px; border-radius: 12px; max-width: 92%; word-break: break-word; font-size: .95rem; }
.msg.user { align-self: flex-end; background: var(--brand); color: var(--brand-ink); white-space: pre-wrap; }
.msg.model { align-self: flex-start; background: var(--bg); border: 1px solid var(--line); }
.msg.model table { margin: 6px 0; font-size: .85rem; }
.msg.model p { margin: 6px 0; } .msg.model ul, .msg.model ol { margin: 6px 0; padding-left: 20px; }
.msg .tools { font-size: .78rem; color: var(--muted); margin-top: 6px; border-top: 1px dashed var(--line); padding-top: 6px; }