:root {
  --bg: #ffffff; --bg-soft: #f7f7f8; --hero: #ffffff; --fg: #111113; --muted: #6b6b73; --line: #ececee;
  --accent: #111113; --accent-hover: #34343a; --accent-fg: #fff; --link: #1d5fa8; --card: #fff; --warn: #b3261e; --ok: #1e6b3a;
  --radius: 10px;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #111113; --bg-soft: #1a1a1d; --hero: #111113; --fg: #ededf0; --muted: #a0a0a8; --line: #2a2a2f; --accent: #ededf0; --accent-hover: #ffffff; --accent-fg: #111113; --link: #7fb0ec; --card: #161618; --warn: #f2948c; --ok: #7fcf9a; }
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--fg); font: 15px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif; }
a { color: var(--link); text-decoration: none; }
a:hover { text-decoration: underline; }
.wrap { max-width: 960px; margin: 0 auto; padding: 0 16px; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.muted { color: var(--muted); }
.small { font-size: .82rem; }
code { font: .88em ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; background: var(--bg-soft); padding: 1px 4px; border-radius: 3px; }

/* top bar */
.topbar { border-bottom: 1px solid var(--line); background: var(--bg); }
.topbar-in { display: flex; align-items: center; justify-content: space-between; height: 54px; gap: 12px; }
.brand { display: inline-flex; align-items: center; gap: 8px; font-weight: 700; color: var(--fg); font-size: 1.02rem; }
.brand:hover { text-decoration: none; }
.topnav { display: flex; gap: 18px; font-size: .9rem; }
.topnav a { color: var(--muted); }
.topnav a:hover { color: var(--fg); text-decoration: none; }

/* hero + tool */
.hero { background: var(--hero); padding: 32px 0 26px; border-bottom: 1px solid var(--line); }
.hero h1 { font-size: clamp(1.55rem, 3.4vw, 2.05rem); line-height: 1.2; margin: 0 0 6px; text-align: center; letter-spacing: -.01em; }
.subtitle { text-align: center; color: var(--muted); margin: 0 auto 22px; max-width: 620px; }
.tool { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 18px; box-shadow: 0 1px 2px rgba(16, 24, 40, .05); }
.convert-row { display: flex; align-items: center; justify-content: center; gap: 10px; margin-bottom: 14px; }
.pill, .pill-select { min-width: 0; max-width: 46vw; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.pill { display: inline-block; padding: 6px 14px; border-radius: var(--radius); font-weight: 600; font-size: .92rem; border: 1px solid var(--line); background: var(--bg-soft); }
.arrow { color: var(--muted); font-size: 1.1rem; }
.pill-select { font: inherit; font-weight: 600; font-size: .92rem; padding: 6px 10px; border-radius: var(--radius); border: 1px solid var(--line); background: var(--card); color: var(--fg); cursor: pointer; }
.drop { border: 2px dashed var(--line); border-radius: var(--radius); padding: 28px 16px; text-align: center; cursor: pointer; display: flex; flex-direction: column; align-items: center; gap: 6px; background: var(--bg-soft); transition: border-color .15s, background .15s; }
.drop.over, .drop:focus-visible { border-color: var(--accent); background: var(--hero); outline: none; }
.btn-choose, .btn-primary { display: inline-block; background: var(--accent); color: var(--accent-fg); font-weight: 600; padding: 10px 26px; border-radius: var(--radius); border: 0; font-size: 1rem; cursor: pointer; }
.drop:hover .btn-choose, .btn-primary:hover { background: var(--accent-hover); }
.btn-primary:disabled { opacity: .6; cursor: progress; }
.drop-hint { color: var(--fg); font-size: .92rem; }
.drop-meta { color: var(--muted); font-size: .8rem; }
.status { min-height: 1.3em; margin: 12px 2px 0; font-size: .9rem; }
.status:empty { display: none; }
.status.busy { color: var(--muted); }
.status.busy::before { content: ""; display: inline-block; width: 10px; height: 10px; margin-right: 8px; border: 2px solid var(--line); border-top-color: var(--accent); border-radius: 50%; animation: spin .8s linear infinite; vertical-align: -1px; }
@keyframes spin { to { transform: rotate(360deg); } }
.status.error { color: var(--warn); }
.status.ok { color: var(--ok); }
.trust { list-style: none; display: flex; justify-content: center; flex-wrap: wrap; gap: 6px 22px; padding: 0; margin: 14px 0 0; font-size: .85rem; color: var(--muted); }
.trust li::before { content: "✓"; color: var(--ok); margin-right: 6px; font-weight: 700; }

/* layer table */
.table-wrap { overflow-x: auto; }
table { border-collapse: collapse; width: 100%; font-size: .9rem; }
.layers { margin-top: 14px; }
.layers th, .layers td, .spec th, .spec td { text-align: left; padding: 8px 10px; border-bottom: 1px solid var(--line); vertical-align: middle; }
.layers thead th, .spec thead th { font-size: .78rem; text-transform: uppercase; letter-spacing: .04em; color: var(--muted); font-weight: 600; background: var(--bg-soft); }
.layers td.lname { font-weight: 600; overflow-wrap: anywhere; }
.layers td.num, .layers th.num { text-align: right; font-variant-numeric: tabular-nums; }
.layers .c-check { width: 32px; }
.layers tr.is-table td { color: var(--muted); }
.link { background: none; border: none; color: var(--link); cursor: pointer; font: inherit; padding: 0; }
.link:hover { text-decoration: underline; }
.actions { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; margin-top: 14px; }
.actions-note { color: var(--muted); font-size: .82rem; }
.map { height: 360px; border-radius: var(--radius); margin-top: 14px; border: 1px solid var(--line); }
table.attr { font-size: .78rem; }
table.attr th { text-align: left; padding-right: 8px; }

/* content */
.content { padding-top: 8px; padding-bottom: 24px; max-width: 760px; }
.content h2 { font-size: 1.15rem; margin: 32px 0 10px; }
.intro p { color: var(--fg); }
.steps { padding-left: 20px; }
.steps li { margin-bottom: 6px; }
details { border-bottom: 1px solid var(--line); padding: 10px 0; }
details p { margin: 8px 0 2px; color: var(--muted); }
summary { cursor: pointer; font-weight: 600; }
.compare th, .compare td { border-bottom: 1px solid var(--line); padding: 8px 6px; text-align: left; }
.linkgrid { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 8px; }
.linkgrid a { display: block; padding: 9px 12px; border: 1px solid var(--line); border-radius: var(--radius); color: var(--fg); font-size: .9rem; background: var(--card); }
.linkgrid a:hover { border-color: var(--accent); color: var(--accent); text-decoration: none; }

/* footer */
.footer { border-top: 1px solid var(--line); background: var(--bg-soft); padding: 22px 0 18px; margin-top: 36px; }
.footer-in { display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; }
.footer-links { display: flex; gap: 18px; font-size: .9rem; align-items: flex-start; }
.footer-links a { color: var(--muted); }
.legal { margin-top: 14px; }
.prose { max-width: 720px; padding-top: 24px; padding-bottom: 24px; }

@media (max-width: 560px) {
  .topnav { gap: 12px; font-size: .85rem; }
  .hero { padding-top: 22px; }
  .layers th:nth-child(5), .layers td:nth-child(5) { display: none; }
}

/* ---- Style A: minimal white (chosen 2026-11-03) ---- */
body { font-size: 15.5px; }
.topbar { border-bottom: 0; }
.hero { border-bottom: 0; padding: 56px 0 12px; }
.hero h1 { font-size: clamp(1.7rem, 4vw, 2.3rem); font-weight: 650; letter-spacing: -.025em; }
.subtitle { font-size: 1.02rem; margin-bottom: 30px; }
.tool { border: 0; box-shadow: none; padding: 0; background: transparent; max-width: 720px; margin: 0 auto; }
.convert-row { margin-bottom: 18px; }
.pill, .pill-select { border: 0; background: var(--bg-soft); border-radius: 999px; padding: 7px 16px; }
.drop { border: 1.5px dashed var(--line); background: var(--bg-soft); border-radius: 14px; padding: 44px 16px; }
.drop.over, .drop:focus-visible { border-color: var(--fg); background: var(--bg-soft); }
.btn-choose, .btn-primary { border-radius: 999px; padding: 11px 30px; }
.trust { margin-top: 22px; }
.trust li::before { color: var(--fg); }
.layers thead th, .spec thead th { background: transparent; }
.status.busy::before { border-top-color: var(--fg); }
.content { padding-top: 32px; }
.intro p { color: var(--muted); }
.linkgrid a { border: 0; background: var(--bg-soft); }
.linkgrid a:hover { color: var(--link); }
.footer { background: var(--bg); border-top: 1px solid var(--line); }
@media (max-width: 560px) { .hero { padding-top: 32px; } .drop { padding: 32px 12px; } }
.fileinfo { margin: 14px 0 0; font-weight: 600; }
pre { white-space: pre-wrap; background: var(--bg-soft); padding: 12px; border-radius: 8px; }
.beta { font-size: .45em; vertical-align: middle; padding: 3px 9px; border-radius: 999px; background: var(--bg-soft); color: var(--muted); font-weight: 600; letter-spacing: 0; }
.warnbox { border-left: 3px solid var(--warn); padding: 8px 12px; background: var(--bg-soft); border-radius: 6px; margin: 14px 0 0; }
.spec th { width: 34%; color: var(--muted); font-weight: 500; }
.err { color: var(--warn); }
.drop-hint a { color: var(--link); text-decoration: underline; }