:root {
  --bg: #faf9f6; --panel: #fff; --ink: #1f2328; --muted: #6b7280; --line: #e5e3dd;
  --accent: #2563eb; --accent-ink: #fff; --del-bg: #fde8e8; --del: #b91c1c; --ins-bg: #dcfce7; --ins: #15803d;
  --mark: #fef3c7; --key-bg: #f3f4f6; --key-line: #c9ccd1;
}
* { box-sizing: border-box; }
html, body { margin: 0; height: 100%; }
body { font: 17px/1.55 -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif; color: var(--ink); background: var(--bg); }
a { color: var(--accent); }
button { font: inherit; }
h1 { font-size: 1.6rem; margin: 0 0 .25rem; }
h2 { font-size: 1.1rem; margin: 1.6rem 0 .6rem; color: var(--muted); font-weight: 600; text-transform: uppercase; letter-spacing: .04em; font-size: .8rem; }
.muted { color: var(--muted); }
kbd { display: inline-block; min-width: 1.9em; padding: .1em .45em; text-align: center; font: 600 .85em/1.5 ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  color: var(--ink); background: var(--key-bg); border: 1px solid var(--key-line); border-bottom-width: 3px; border-radius: 6px; margin: 0 .15em; vertical-align: middle; }
.btn { display: inline-flex; align-items: center; gap: .5em; padding: .55em 1em; border-radius: 8px; border: 1px solid var(--line); background: var(--panel); color: var(--ink); cursor: pointer; text-decoration: none; }
.btn.primary { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); }
.btn:hover { filter: brightness(.97); }
.btn kbd { margin-left: .2em; }
.primary kbd { background: rgba(255,255,255,.2); border-color: rgba(255,255,255,.35); color: #fff; }

/* login */
body.login { display: flex; align-items: center; justify-content: center; }
.login-box { background: var(--panel); border: 1px solid var(--line); border-radius: 12px; padding: 2rem; width: min(420px, 92vw); display: flex; flex-direction: column; gap: .8rem; }
.login-box input { font: inherit; padding: .6em .8em; border: 1px solid var(--key-line); border-radius: 8px; }
.login-box button { padding: .6em; border-radius: 8px; border: 0; background: var(--accent); color: #fff; cursor: pointer; }
.err { color: var(--del); margin: 0; }

/* layout */
#app { min-height: 100%; }
.home { display: grid; grid-template-columns: 300px 1fr; min-height: 100vh; }
nav.chapters { border-right: 1px solid var(--line); background: var(--panel); padding: 1.2rem 0; overflow-y: auto; }
nav.chapters .title { padding: 0 1.2rem .8rem; font-weight: 600; }
nav.chapters a { display: flex; justify-content: space-between; gap: .6rem; padding: .45rem 1.2rem; color: var(--ink); text-decoration: none; font-size: .95rem; }
nav.chapters a:hover { background: var(--bg); }
nav.chapters a.empty { color: var(--muted); }
nav.chapters .count { color: var(--muted); font-variant-numeric: tabular-nums; white-space: nowrap; }
nav.chapters .count.done { color: var(--ins); }
main.content { padding: 2rem 3rem; max-width: 900px; }
.progress { height: 8px; background: var(--line); border-radius: 4px; overflow: hidden; margin: .8rem 0 .3rem; }
.progress > div { height: 100%; background: var(--ins); }
.actions { display: flex; gap: .8rem; flex-wrap: wrap; margin: 1rem 0; }
.slider { display: grid; grid-template-columns: 1fr auto; gap: .5rem 1rem; align-items: center; background: var(--panel); border: 1px solid var(--line); border-radius: 10px; padding: 1rem 1.2rem; }
.slider input[type=range] { width: 100%; }
.slider .ends { display: flex; justify-content: space-between; font-size: .8rem; color: var(--muted); }
.slider output { font-variant-numeric: tabular-nums; white-space: nowrap; }
.legend { display: grid; grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); gap: .5rem 2rem; }
.legend div { display: flex; gap: .8rem; align-items: baseline; padding: .3rem 0; }
.legend .keys { min-width: 5.5em; text-align: right; }
.downloads a { display: block; padding: .4rem 0; }
.chat { background: var(--panel); border: 1px solid var(--line); border-radius: 10px; padding: 1rem 1.2rem; }
.chat > p { margin: 0 0 .8rem; font-size: .95rem; }
.chat .messages { max-height: 22rem; overflow-y: auto; display: flex; flex-direction: column; gap: .6rem; padding: .2rem 0 .6rem; }
.chat .msg { max-width: 85%; padding: .5rem .8rem; border-radius: 10px; background: var(--bg); }
.chat .msg.dad { align-self: flex-end; background: #e8effd; }
.chat .msg .who { font-size: .75rem; color: var(--muted); margin-bottom: .15rem; }
.chat .msg .body { white-space: pre-wrap; }
.chat form { display: flex; gap: .6rem; align-items: flex-end; }
.chat textarea { flex: 1; font: inherit; padding: .5em .7em; border: 1px solid var(--key-line); border-radius: 8px; resize: vertical; }

/* focus */
.focus { max-width: 760px; margin: 0 auto; padding: 1.5rem 1.2rem 4rem; }
.focus .top { display: flex; justify-content: space-between; align-items: baseline; gap: 1rem; color: var(--muted); font-size: .9rem; margin-bottom: 1.4rem; }
.chip { display: inline-block; padding: .1em .55em; border-radius: 999px; font-size: .78rem; background: var(--key-bg); color: var(--ink); margin-left: .4em; vertical-align: middle; }
.chip.hi { background: var(--ins-bg); color: var(--ins); } .chip.mid { background: var(--mark); color: #92400e; } .chip.lo { background: var(--key-bg); color: var(--muted); }
.diff { font-family: Georgia, "Times New Roman", serif; font-size: 1.35rem; line-height: 1.6; background: var(--panel); border: 1px solid var(--line); border-radius: 12px; padding: 1.4rem 1.6rem; white-space: pre-wrap; word-wrap: break-word; }
.diff .ctx { color: var(--muted); font-size: 1rem; line-height: 1.5; margin: 0 0 .8rem; }
.diff .ctx.after { margin: .8rem 0 0; }
del { background: var(--del-bg); color: var(--del); text-decoration: line-through; text-decoration-thickness: 2px; border-radius: 3px; padding: 0 .1em; }
ins { background: var(--ins-bg); color: var(--ins); text-decoration: none; border-radius: 3px; padding: 0 .1em; font-weight: 600; }
mark { background: var(--mark); border-radius: 3px; padding: 0 .1em; }
.sp { display: inline-block; width: .5em; text-align: center; color: inherit; opacity: .55; }
.sp::before { content: "·"; }
.inv { display: inline-block; font: 600 .6em/1.4 -apple-system, "Segoe UI", sans-serif; letter-spacing: .03em; text-transform: uppercase; border: 1px solid currentColor; border-radius: 4px; padding: 0 .35em; margin: 0 .15em; vertical-align: middle; opacity: .8; }
.note { margin: .8rem .2rem 0; color: var(--muted); font-size: .95rem; }
.editor-wrap { margin-top: 1.2rem; }
.editor-wrap label { display: flex; justify-content: space-between; font-size: .8rem; color: var(--muted); text-transform: uppercase; letter-spacing: .04em; margin: 0 .2rem .35rem; }
textarea.editor { width: 100%; font: 1.15rem/1.55 Georgia, "Times New Roman", serif; padding: .9rem 1.1rem; border: 2px solid var(--line); border-radius: 12px; background: var(--panel); color: var(--ink); resize: vertical; min-height: 5.5rem; }
textarea.editor:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 4px rgba(37,99,235,.15); }
textarea.editor.changed { border-color: var(--ins); }
.status { margin: .6rem .2rem 0; font-size: .9rem; min-height: 1.4em; }
.status.err { color: var(--del); }
.hint { margin-top: 1.6rem; color: var(--muted); font-size: .85rem; display: flex; flex-wrap: wrap; gap: .4rem 1.4rem; }
.hint span { white-space: nowrap; }

/* review + log */
.page { max-width: 900px; margin: 0 auto; padding: 1.5rem 1.2rem 4rem; }
.page .top { display: flex; justify-content: space-between; align-items: center; gap: 1rem; flex-wrap: wrap; }
.filters { display: flex; gap: .4rem; }
.filters button { border: 1px solid var(--line); background: var(--panel); border-radius: 999px; padding: .25em .9em; cursor: pointer; }
.filters button.on { background: var(--ink); color: #fff; border-color: var(--ink); }
.review h2 { margin-top: 1.8rem; }
.row { display: grid; grid-template-columns: 6.5rem 1fr; gap: 1rem; padding: .7rem .8rem; border: 1px solid var(--line); border-radius: 10px; background: var(--panel); margin-bottom: .5rem; cursor: pointer; font-family: Georgia, "Times New Roman", serif; }
.row:hover { border-color: var(--accent); }
.row .st { font-family: -apple-system, "Segoe UI", Roboto, sans-serif; font-size: .8rem; text-transform: uppercase; letter-spacing: .04em; color: var(--muted); padding-top: .2em; }
.row.changed .st { color: var(--ins); } .row.kept .st { color: var(--muted); } .row.pending .st { color: #92400e; } .row.skipped .st { color: var(--accent); }
.hint.editing { color: var(--accent); }
.hint[hidden] { display: none; }
.row .snippet { white-space: pre-wrap; }
table.log { width: 100%; border-collapse: collapse; font-size: .9rem; }
table.log td, table.log th { text-align: left; padding: .4rem .5rem; border-bottom: 1px solid var(--line); vertical-align: top; }
table.log td.t { white-space: nowrap; color: var(--muted); }
.empty { color: var(--muted); padding: 2rem 0; }
@media (max-width: 760px) {
  .home { grid-template-columns: 1fr; }
  nav.chapters { border-right: 0; border-bottom: 1px solid var(--line); max-height: 40vh; }
  main.content { padding: 1.2rem; }
}