/* windthink.hk — shared styles. system fonts only, zero external requests. */

:root {
  /* cool paper, not cream — neutrals biased toward the teal accent */
  --bg:       #f9fafb;
  --surface:  #ffffff;
  --ink:      #191d22;
  --muted:    #566069;
  --faint:    #8b939c;
  --line:     #e5e9ec;
  --accent:   #2f6d74;
  --accent-2: #275f66;
  --focus:    #2f6d74;
  --sel:      #cfe6e6;

  --font-serif: "Iowan Old Style", "Charter", "Georgia", "Cambria", "Times New Roman", serif;
  --font-sans:  -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, "Helvetica Neue", Arial, sans-serif;

  --measure: 40rem;
  --gap: clamp(1.25rem, 4vw, 2rem);
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg:      #101317;
    --surface: #161a1f;
    --ink:     #e7eaed;
    --muted:   #9aa3ad;
    --faint:   #69727c;
    --line:    #262c33;
    --accent:  #6bb8bd;
    --accent-2:#8fd0d3;
    --focus:   #6bb8bd;
    --sel:     #234043;
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-serif);
  font-size: 1.1875rem;
  line-height: 1.72;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
::selection { background: var(--sel); }

.wrap { max-width: var(--measure); margin: 0 auto; padding: 0 var(--gap); }

a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-2); }
:focus-visible { outline: 2px solid var(--focus); outline-offset: 3px; border-radius: 2px; }

/* ---------- header ---------- */
.site-head { border-bottom: 1px solid var(--line); }
.site-head .wrap {
  display: flex; align-items: baseline; justify-content: space-between;
  gap: 1rem; padding-top: 1.4rem; padding-bottom: 1.4rem;
}
.brand {
  font-family: var(--font-sans);
  font-weight: 600; font-size: 1.06rem; letter-spacing: -0.01em;
  color: var(--ink);
}
.brand:hover { color: var(--ink); }
.brand .dot { color: var(--accent); }
nav.top { font-family: var(--font-sans); font-size: .86rem; display: flex; gap: 1.3rem; }
nav.top a { color: var(--muted); letter-spacing: .01em; }
nav.top a:hover { color: var(--ink); }
nav.top a[aria-current="page"] { color: var(--accent); }

/* ---------- main ---------- */
main { padding: clamp(2.5rem, 7vw, 4.5rem) 0 1rem; }

/* ---------- home ---------- */
.lede { font-size: 1.32rem; line-height: 1.55; margin: 0 0 .4rem; }
.lede .rule { display:block; width: 2.4rem; height: 2px; background: var(--accent); margin: 0 0 1.4rem; border-radius: 2px; }
.by { font-family: var(--font-sans); font-size: .84rem; color: var(--faint); margin: 0 0 3.2rem; }

.list-label {
  font-family: var(--font-sans); font-size: .72rem; text-transform: uppercase;
  letter-spacing: .12em; color: var(--faint); margin: 0 0 1.3rem;
}
ul.posts { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 2rem; }
.posts a.title {
  font-size: 1.28rem; font-weight: 600; letter-spacing: -0.01em; line-height: 1.3;
  color: var(--ink); display: inline-block; margin-bottom: .3rem;
}
.posts a.title:hover { color: var(--accent); }
.posts .dek { color: var(--muted); font-size: 1.02rem; line-height: 1.55; margin: 0; }
.posts .when {
  font-family: var(--font-sans); font-size: .76rem; letter-spacing: .02em;
  color: var(--faint); font-variant-numeric: tabular-nums; display: block; margin-bottom: .35rem;
}

/* ---------- article ---------- */
article h1 {
  font-size: clamp(1.7rem, 4.5vw, 2.15rem); line-height: 1.18; letter-spacing: -0.015em;
  text-wrap: balance; margin: 0 0 .7rem;
}
.meta {
  font-family: var(--font-sans); font-size: .78rem; letter-spacing: .02em; color: var(--faint);
  font-variant-numeric: tabular-nums; margin: 0 0 2.4rem;
}
article p { margin: 0 0 1.35rem; }
article h2 { font-size: 1.28rem; letter-spacing: -0.01em; margin: 2.6rem 0 1rem; line-height: 1.3; }
article ol { padding-left: 0; list-style: none; margin: 0 0 1.35rem; counter-reset: n; }
article ol li { counter-increment: n; position: relative; padding-left: 2.4rem; margin-bottom: 1.15rem; }
article ol li::before {
  content: counter(n); position: absolute; left: 0; top: .05rem;
  font-family: var(--font-sans); font-size: .8rem; font-weight: 600; color: var(--accent);
  font-variant-numeric: tabular-nums;
}
blockquote { margin: 1.6rem 0; padding-left: 1.2rem; border-left: 2px solid var(--line); color: var(--muted); font-style: italic; }
article a { text-decoration: underline; text-decoration-color: color-mix(in srgb, var(--accent) 45%, transparent); text-underline-offset: 2px; }
em { font-style: italic; }
.backlink { font-family: var(--font-sans); font-size: .84rem; display: inline-block; margin-top: 1.8rem; }
.backlink::before { content: "\2190\00a0"; }

/* ---------- now / about ---------- */
.page-title { font-size: clamp(1.6rem, 4.5vw, 2rem); letter-spacing: -0.015em; margin: 0 0 1.6rem; }
.updated { font-family: var(--font-sans); font-size: .78rem; color: var(--faint); margin: 0 0 2rem; }
ul.now { list-style: none; padding: 0; margin: 0 0 2rem; display: flex; flex-direction: column; gap: .95rem; }
ul.now li { position: relative; padding-left: 1.5rem; }
ul.now li::before { content: ""; position: absolute; left: 0; top: .78rem; width: .5rem; height: 2px; background: var(--accent); }
.aside { color: var(--muted); font-size: 1rem; }

/* ---------- 404 ---------- */
.notfound { text-align: left; }
.notfound .code { font-family: var(--font-sans); font-size: .8rem; letter-spacing: .12em; text-transform: uppercase; color: var(--faint); margin: 0 0 .8rem; }

/* ---------- footer ---------- */
.site-foot { border-top: 1px solid var(--line); margin-top: 4rem; }
.site-foot .wrap {
  padding-top: 2rem; padding-bottom: 3rem;
  display: flex; flex-wrap: wrap; gap: .4rem 1.4rem; align-items: baseline;
  font-family: var(--font-sans); font-size: .82rem; color: var(--faint);
}
.site-foot a { color: var(--muted); }
.site-foot a:hover { color: var(--ink); }
.site-foot .sep { color: var(--line); }
.site-foot .copy { margin-left: auto; }