:root {
  --paper: #f6f0e4; --card: #fffaf0; --ink: #2a241d; --muted: #6b5f50; --line: #e2d6bf; --accent: #2f4f46; --accent-ink: #fffaf0;
  --brass: #b88a2e; --warn: #8e2f2f; --warn-bg: #f7e3dc; --info-bg: #e6eef0; --ok-bg: #e4efe4; --field: #fffdf8;
  --d-revolving: #2f6f7c; --d-swing: #8c5a2b; --d-stable: #3f6e4f; --d-trapdoor: #5a3424; --d-ink: #ffffff;
  --shadow: 0 1px 0 rgba(60, 40, 10, 0.06), 0 6px 18px rgba(60, 40, 10, 0.06);
  --bg: var(--paper); --panel: var(--card); --accent-btn: var(--accent);
}
html[data-theme="dark"] {
  --paper: #1b181d; --card: #242027; --ink: #efe6d8; --muted: #b6aa99; --line: #3a3340; --accent: #8fc2b1; --accent-ink: #13201c;
  --brass: #d6aa4e; --warn: #ff8f80; --warn-bg: #3a2222; --info-bg: #1f2d33; --ok-bg: #1f2e22; --field: #1d1a20;
  --d-revolving: #7fc1cd; --d-swing: #e0a56c; --d-stable: #8fcf9f; --d-trapdoor: #e7b39a; --d-ink: #17131a;
  --shadow: none;
}
* { box-sizing: border-box; }
html, body { margin: 0; }
body { background: var(--paper); color: var(--ink); font: 16px/1.5 "Avenir Next", "Segoe UI", Helvetica, Arial, sans-serif; }
a { color: var(--accent); }
h1, h2, h3, .brand strong { font-family: Georgia, "Iowan Old Style", serif; }
.hidden { display: none !important; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.small { font-size: 0.88rem; } .muted { color: var(--muted); }

.top, .bar { display: flex; align-items: center; gap: 12px; padding: 10px 18px; border-bottom: 2px solid var(--brass); background: var(--card); position: sticky; top: 0; z-index: 5; flex-wrap: wrap; }
.back { text-decoration: none; color: var(--muted); font-size: 0.9rem; }
.brand { display: flex; align-items: center; gap: 8px; font-size: 1.15rem; }
.logo { width: 24px; height: 24px; }
.lg-f { fill: var(--accent); } .lg-s { fill: #bfe0e6; } .lg-b { fill: #4c7a5b; } .lg-k { fill: var(--brass); }
.session { margin-left: auto; display: flex; gap: 6px; align-items: center; flex-wrap: wrap; }
.chip-s { font-size: 0.85rem; color: var(--muted); border: 1px solid var(--line); border-radius: 999px; padding: 4px 10px; }

.btn, .pill { font: inherit; font-size: 0.9rem; border: 1.5px solid var(--accent); color: var(--accent); background: transparent; border-radius: 6px; padding: 6px 12px; cursor: pointer; text-decoration: none; display: inline-block; line-height: 1.3; }
.btn:hover, .pill:hover { background: var(--info-bg); }
.btn.solid, .pill.solid { background: var(--accent); color: var(--accent-ink); }
.btn.solid:hover { filter: brightness(1.08); background: var(--accent); }
.btn.big { font-size: 1.05rem; padding: 10px 18px; }
.btn.tiny, .pill.tiny { font-size: 0.8rem; padding: 4px 9px; }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }

main { max-width: 1040px; margin: 0 auto; padding: 18px 16px 30px; }
.hero { padding: 14px 0 6px; }
.eyebrow { margin: 0; text-transform: uppercase; letter-spacing: 0.14em; font-size: 0.78rem; color: var(--brass); font-weight: 600; }
h1 { font-size: 2.4rem; margin: 4px 0 8px; line-height: 1.1; }
h1 .sub { display: block; font-size: 1.1rem; font-weight: 400; font-style: italic; color: var(--muted); margin-top: 6px; }
.lede { max-width: 720px; }
.samples { display: flex; gap: 8px; flex-wrap: wrap; align-items: center; margin: 8px 0 4px; }
.sample { font: inherit; font-size: 0.86rem; border: 1px dashed var(--brass); background: var(--card); color: var(--ink); border-radius: 4px 14px 14px 4px; padding: 5px 12px 5px 10px; cursor: pointer; }
.sample.on { border-style: solid; background: var(--brass); color: #20170a; }

.card { background: var(--card); border: 1px solid var(--line); border-radius: 10px; padding: 16px 18px; margin: 16px 0; box-shadow: var(--shadow); }
.ch { margin: 0 0 10px; font-size: 1.3rem; display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.no { display: inline-grid; place-items: center; width: 28px; height: 28px; border-radius: 50%; background: var(--accent); color: var(--accent-ink); font-size: 0.95rem; }
.free, .paid { font-family: "Avenir Next", Helvetica, Arial, sans-serif; font-size: 0.72rem; text-transform: uppercase; letter-spacing: 0.08em; border-radius: 4px; padding: 2px 7px; }
.free { background: var(--ok-bg); color: var(--d-stable); } .paid { background: var(--warn-bg); color: var(--warn); }
.fld { margin: 8px 0; }
.lab { display: block; font-size: 0.85rem; font-weight: 600; margin-bottom: 3px; }
.inp { width: 100%; font: inherit; color: var(--ink); background: var(--field); border: 1px solid var(--line); border-radius: 6px; padding: 7px 9px; }
.inp:focus { outline: 2px solid var(--accent); outline-offset: 1px; }
select.inp { padding: 6px 6px; }
.actions { display: flex; gap: 8px; flex-wrap: wrap; align-items: center; margin: 10px 0 4px; }
.note { background: var(--info-bg); border-left: 3px solid var(--accent); padding: 8px 10px; border-radius: 4px; font-size: 0.9rem; }

.rows { list-style: none; padding: 0; margin: 8px 0; counter-reset: row; }
.row { border: 1px solid var(--line); border-left: 6px solid var(--line); border-radius: 8px; padding: 10px 12px; margin: 10px 0; background: var(--paper); }
.row.d-revolving { border-left-color: var(--d-revolving); } .row.d-swing { border-left-color: var(--d-swing); }
.row.d-stable { border-left-color: var(--d-stable); } .row.d-trapdoor { border-left-color: var(--d-trapdoor); }
.rowtop { display: flex; gap: 8px; align-items: center; }
.rowno { font-family: Georgia, serif; font-weight: 700; min-width: 1.4em; }
.rowtop .inp { flex: 1; }
.rowq { display: grid; grid-template-columns: repeat(5, 1fr); gap: 8px; margin-top: 8px; }
.rowq .lab { font-weight: 500; font-size: 0.78rem; color: var(--muted); }
.rownote { margin-top: 6px; }
.rowdoor { font-size: 0.82rem; margin-top: 6px; }
.x { font: inherit; border: none; background: transparent; color: var(--muted); cursor: pointer; font-size: 1.2rem; line-height: 1; padding: 4px 6px; }
.x:hover { color: var(--warn); }

.dtag { display: inline-block; font-size: 0.78rem; font-weight: 700; border-radius: 3px; padding: 1px 7px; color: var(--d-ink); white-space: nowrap; }
.dtag.d-revolving { background: var(--d-revolving); } .dtag.d-swing { background: var(--d-swing); }
.dtag.d-stable { background: var(--d-stable); } .dtag.d-trapdoor { background: var(--d-trapdoor); }
.stall { color: var(--warn); font-weight: 600; }

.drawing { width: 100%; border-radius: 8px; overflow: hidden; border: 1px solid var(--line); }
.drawing svg { width: 100%; height: auto; display: block; }
.tablewrap { overflow-x: auto; margin-top: 10px; }
table.doors { width: 100%; border-collapse: collapse; font-size: 0.9rem; }
table.doors th, table.doors td { text-align: left; padding: 6px 8px; border-bottom: 1px solid var(--line); vertical-align: top; }
table.doors td.none { color: var(--muted); font-style: italic; }

.progress { border: 1px dashed var(--brass); border-radius: 8px; padding: 10px 12px; margin: 10px 0; }
.steps { list-style: none; padding: 0; margin: 6px 0; }
.step { color: var(--muted); } .step.done { color: var(--d-stable); } .step.active { color: var(--ink); font-weight: 600; }
.step-ic { display: inline-block; width: 1em; font-family: monospace; }
.raw { white-space: pre-wrap; background: var(--paper); padding: 10px; border-radius: 6px; font-size: 0.82rem; max-height: 320px; overflow: auto; }

.result { margin-top: 12px; border-top: 2px solid var(--brass); padding-top: 10px; }
.result.empty .rcards, .result.empty #rReconH, .result.empty .recon { display: none; }
.rhead { display: flex; justify-content: space-between; gap: 10px; align-items: center; flex-wrap: wrap; }
.badge { font-size: 0.75rem; letter-spacing: 0.08em; border: 1px solid var(--line); border-radius: 4px; padding: 2px 8px; color: var(--muted); }
.badge.on { border-color: var(--accent); color: var(--accent); }
.headline { font-family: Georgia, serif; font-size: 1.2rem; margin: 10px 0; }
.rcards { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; }
.rcard { border: 1px solid var(--line); border-top: 5px solid var(--line); border-radius: 8px; padding: 10px 12px; background: var(--paper); }
.rcard.d-revolving { border-top-color: var(--d-revolving); } .rcard.d-swing { border-top-color: var(--d-swing); }
.rcard.d-stable { border-top-color: var(--d-stable); } .rcard.d-trapdoor { border-top-color: var(--d-trapdoor); }
.rcard h4 { margin: 0 0 6px; font-family: Georgia, serif; font-size: 1.02rem; }
.rcard dl { margin: 0; font-size: 0.88rem; }
.rcard dt { font-weight: 700; font-size: 0.74rem; text-transform: uppercase; letter-spacing: 0.06em; color: var(--muted); margin-top: 6px; }
.rcard dd { margin: 1px 0 0; }
.rcard .moved { background: var(--info-bg); border-radius: 4px; padding: 4px 6px; margin-top: 6px; font-size: 0.85rem; }
.rcard .copy1 { margin-top: 8px; }
.recon { padding-left: 18px; font-size: 0.9rem; }
.recon li.bad { color: var(--warn); font-weight: 600; } .recon li.warn { color: var(--warn); } .recon li.none { color: var(--muted); list-style: none; margin-left: -18px; }
.saved { list-style: none; padding: 0; margin: 8px 0; }
.hrow { display: flex; gap: 10px; justify-content: space-between; align-items: center; border-bottom: 1px solid var(--line); padding: 8px 0; }
.hrow.none { color: var(--muted); font-style: italic; }
.hinfo { display: flex; flex-direction: column; min-width: 0; } .hinfo b { overflow-wrap: anywhere; }
.hbtns { display: flex; gap: 6px; flex-shrink: 0; }
.about p { max-width: 820px; }
.foot { max-width: 1040px; margin: 0 auto; padding: 8px 16px 40px; font-size: 0.85rem; color: var(--muted); }
.toasts { position: fixed; right: 14px; bottom: 14px; display: flex; flex-direction: column; gap: 8px; z-index: 20; max-width: min(380px, calc(100vw - 28px)); }
.toast { background: var(--card); border: 1px solid var(--line); border-left: 4px solid var(--accent); border-radius: 6px; padding: 8px 12px; font-size: 0.9rem; box-shadow: 0 4px 14px rgba(0, 0, 0, 0.15); transition: opacity 0.5s; }
.toast.err { border-left-color: var(--warn); } .toast.gone { opacity: 0; }

@media (max-width: 760px) {
  .rowq { grid-template-columns: repeat(2, 1fr); }
  .rcards { grid-template-columns: 1fr; }
  h1 { font-size: 2rem; }
}
@media (max-width: 420px) {
  .drawing { overflow-x: auto; }
  .drawing svg { min-width: 680px; }
  .top { padding: 8px 12px; gap: 8px; }
  .back-t { display: none; }
  .brand { font-size: 1rem; }
  .btn { padding: 5px 9px; }
  .card { padding: 12px 12px; }
  .rowq { grid-template-columns: 1fr 1fr; gap: 6px; }
  table.doors th:nth-child(4), table.doors td:nth-child(4) { display: none; }
}
@media print {
  .top, .samples, .actions, .exports, #runBtn, .toasts, .foot, .hero .lede { display: none !important; }
  .card { box-shadow: none; break-inside: avoid; }
}