/* Mobify — "field notebook" visual identity.
   Parchment paper, moss + clay ink, squared cards, monospace specimen labels. */
:root {
  --paper: #f6f1e4;
  --paper-2: #efe8d6;
  --ink: #24211b;
  --ink-soft: #5d574a;
  --rule: #cdc3ab;
  --moss: #5f7742;
  --moss-dark: #3f5230;
  --clay: #a85c34;
  --card: #fbf8ef;
  --serif: Georgia, "Iowan Old Style", "Times New Roman", serif;
  --mono: ui-monospace, "SFMono-Regular", "Cascadia Mono", Consolas, monospace;
  --sans: "Segoe UI", system-ui, -apple-system, sans-serif;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background:
    repeating-linear-gradient(0deg, rgba(159,140,96,0.055) 0 27px, transparent 27px 28px),
    var(--paper);
  color: var(--ink);
  font: 17px/1.7 var(--sans);
  -webkit-font-smoothing: antialiased;
}

a { color: var(--moss-dark); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 3px; }

h1, h2, h3 { font-family: var(--serif); line-height: 1.22; color: var(--ink); }

.zh { color: var(--ink-soft); }

/* ---------- masthead ---------- */
.masthead { border-bottom: 3px double var(--rule); background: rgba(251,248,239,0.75); }
.masthead__bar {
  max-width: 1060px; margin: 0 auto; padding: 22px 22px 10px;
  display: flex; flex-wrap: wrap; align-items: baseline; gap: 8px 16px;
}
.brand { display: inline-flex; align-items: center; gap: 9px; }
.brand__mark { font-size: 22px; }
.brand__word {
  font-family: var(--serif); font-size: 30px; letter-spacing: 0.5px;
  color: var(--moss-dark); font-weight: 700;
}
.brand__sub { margin: 0; font-size: 13.5px; color: var(--ink-soft); letter-spacing: 0.04em; }
.tabs {
  max-width: 1060px; margin: 0 auto; padding: 0 14px 12px;
  display: flex; flex-wrap: wrap; gap: 2px;
}
.tab {
  font: 13.5px/1 var(--sans); letter-spacing: 0.03em;
  padding: 9px 13px; color: var(--ink-soft);
  border: 1px solid transparent; border-radius: 4px;
}
.tab:hover { background: var(--paper-2); text-decoration: none; color: var(--ink); }
.tab.is-active { color: var(--moss-dark); border-color: var(--rule); background: var(--card); font-weight: 600; }

.wrap { max-width: 1060px; margin: 0 auto; padding: 30px 22px 10px; }
.wrap--narrow { max-width: 760px; }

.crumb { font: 13px/1.6 var(--mono); color: var(--ink-soft); letter-spacing: 0.02em; margin: 0 0 18px; }
.crumb span { opacity: 0.6; }

/* ---------- hero ---------- */
.hero {
  max-width: 1060px; margin: 0 auto; padding: 54px 22px 34px;
  border-bottom: 1px dashed var(--rule);
}
.hero__kicker {
  font: 12.5px/1 var(--mono); text-transform: uppercase; letter-spacing: 0.18em;
  color: var(--clay); margin: 0 0 16px;
}
.hero__title { font-size: clamp(34px, 5.4vw, 58px); margin: 0 0 18px; font-weight: 700; }
.hero__title em { color: var(--moss); font-style: italic; }
.hero__lede { max-width: 60ch; font-size: 18.5px; color: var(--ink-soft); margin: 0 0 14px; }
.hero__meta { font: 13px/1.6 var(--mono); color: var(--clay); margin: 0; }

.section-title {
  font-family: var(--sans); font-size: 14px; font-weight: 700; text-transform: uppercase;
  letter-spacing: 0.16em; color: var(--ink-soft); max-width: 1060px;
  margin: 44px auto 20px; padding: 0 22px;
}
.section-title span { font-family: var(--mono); color: var(--clay); margin-right: 10px; }

/* ---------- chapters ---------- */
.chapter-grid {
  max-width: 1060px; margin: 0 auto; padding: 0 22px;
  list-style: none; display: grid; gap: 18px;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
}
.chapter {
  background: var(--card); border: 1px solid var(--rule);
  border-top: 4px solid var(--moss);
  padding: 18px 18px 14px; box-shadow: 4px 4px 0 rgba(95,119,66,0.10);
}
.chapter__head { color: inherit; }
.chapter__head:hover { text-decoration: none; }
.chapter__head h3 { margin: 4px 0 0; font-size: 20px; color: var(--moss-dark); }
.chapter:hover .chapter__head h3 { color: var(--clay); }
.chapter__no { font: 11.5px/1 var(--mono); letter-spacing: 0.14em; color: var(--clay); }
.chapter__intro { font-size: 15px; color: var(--ink-soft); margin: 10px 0; }
.chapter__count { font: 12px/1 var(--mono); color: var(--ink-soft); margin: 0 0 10px; }
.chapter__list { list-style: none; margin: 0; padding: 0; border-top: 1px dotted var(--rule); }
.chapter__list li { padding: 7px 0; border-bottom: 1px dotted var(--rule); font-size: 15px; }
.chapter__list .muted { color: var(--ink-soft); font-style: italic; }

/* ---------- note list ---------- */
.note-list { list-style: none; margin: 0; padding: 0; }
.note {
  display: grid; grid-template-columns: 46px 1fr; gap: 16px;
  padding: 18px 0; border-bottom: 1px solid var(--rule);
}
.note__no {
  font: 15px/1.4 var(--mono); color: #fff; background: var(--moss);
  width: 34px; height: 34px; display: grid; place-items: center; border-radius: 50%;
}
.note__title { margin: 2px 0 4px; font-size: 22px; }
.note__title a { color: var(--ink); }
.note__title a:hover { color: var(--clay); text-decoration: none; }
.note__cat { font: 12px/1.4 var(--mono); color: var(--ink-soft); margin: 0 0 6px; text-transform: uppercase; letter-spacing: 0.06em; }
.note__desc { margin: 0; color: var(--ink-soft); font-size: 15.5px; }
.empty { padding: 20px 0; color: var(--ink-soft); font-style: italic; }
.latest { padding-bottom: 30px; }

/* ---------- chapter page ---------- */
.chapter-hero { border-left: 5px solid var(--moss); padding: 4px 0 4px 18px; margin: 0 0 30px; }
.chapter-hero h1 { font-size: clamp(30px, 4.4vw, 44px); margin: 0 0 10px; }
.chapter-hero__intro { font-size: 17.5px; color: var(--ink-soft); margin: 0 0 10px; max-width: 62ch; }
.chapter-hero__count { font: 12.5px/1 var(--mono); color: var(--clay); margin: 0; }

/* ---------- article ---------- */
.note-art { max-width: 1060px; margin: 0 auto; }
.note-art__head { border-bottom: 3px double var(--rule); padding-bottom: 20px; margin-bottom: 26px; }
.note-art__head h1 { font-size: clamp(31px, 4.6vw, 46px); margin: 0 0 6px; }
.note-art__zh { font-family: var(--serif); color: var(--clay); font-size: 17px; margin: 0 0 12px; }
.note-art__lede { font-size: 19px; color: var(--ink-soft); margin: 0; max-width: 68ch; }

.label {
  float: right; width: 300px; margin: 0 0 22px 30px;
  background: var(--paper-2); border: 1px solid var(--rule);
  padding: 16px 18px; box-shadow: 4px 4px 0 rgba(168,92,52,0.12);
}
.label__cap {
  font: 11.5px/1 var(--mono); text-transform: uppercase; letter-spacing: 0.18em;
  color: var(--clay); margin: 0 0 12px; border-bottom: 1px dashed var(--rule); padding-bottom: 8px;
}
.label__rows { display: grid; grid-template-columns: auto 1fr; gap: 8px 14px; margin: 0; }
.label__rows dt { font: 12px/1.5 var(--mono); color: var(--ink-soft); text-transform: uppercase; letter-spacing: 0.05em; }
.label__rows dd { margin: 0; font-size: 15px; font-weight: 600; }

.sec { margin: 0 0 30px; }
.sec h2 { font-size: 24px; margin: 0 0 12px; display: flex; align-items: baseline; gap: 12px; }
.sec__no { font: 13px/1 var(--mono); color: var(--clay); }
.sec p { margin: 0 0 15px; }

.seealso {
  clear: both; margin-top: 40px; padding: 20px 22px;
  background: var(--card); border: 1px solid var(--rule); border-left: 5px solid var(--clay);
}
.seealso h2 { font-family: var(--sans); font-size: 13px; text-transform: uppercase; letter-spacing: 0.14em; color: var(--ink-soft); margin: 0 0 12px; }
.seealso ul { margin: 0; padding-left: 18px; }
.seealso li { padding: 4px 0; }

/* ---------- legal ---------- */
.legal-title { font-size: clamp(30px, 4.6vw, 44px); margin: 0 0 20px; }
.prose p { margin: 0 0 15px; color: var(--ink-soft); }

/* ---------- footer ---------- */
.foot { border-top: 3px double var(--rule); margin-top: 46px; background: rgba(239,232,214,0.6); }
.foot__inner { max-width: 1060px; margin: 0 auto; padding: 28px 22px; }
.foot__note { margin: 0 0 14px; color: var(--ink-soft); font-size: 15px; max-width: 66ch; }
.foot__links { display: flex; flex-wrap: wrap; gap: 18px; margin: 0 0 12px; }
.foot__links a { font-size: 14px; letter-spacing: 0.03em; }
.foot__mail { font: 13px/1.6 var(--mono); color: var(--ink-soft); margin: 0; }

@media (max-width: 720px) {
  .label { float: none; width: auto; margin: 0 0 22px; }
  .note { grid-template-columns: 34px 1fr; gap: 12px; }
}