/* My Notes — shared stylesheet
   Layout: single centred column, generous whitespace, one accent.  */
:root {
  --bg: #ffffff;
  --bg-subtle: #f7f7f5;
  --fg: #37352f;
  --fg-muted: #787774;
  --border: #e9e9e7;
  --accent: #2383e2;
  --accent-soft: #e7f0fb;
  --radius: 8px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Sans",
          "Hiragino Kaku Gothic ProN", "Noto Sans JP", Meiryo, sans-serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #191919;
    --bg-subtle: #202020;
    --fg: #d4d4d4;
    --fg-muted: #9b9b9b;
    --border: #2f2f2f;
    --accent: #529cca;
    --accent-soft: #1f2d3a;
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.75;
  letter-spacing: .01em;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ---- header ---- */
.site-header {
  position: sticky; top: 0; z-index: 10;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: saturate(180%) blur(8px);
  border-bottom: 1px solid var(--border);
}
.site-header .inner {
  max-width: 760px; margin: 0 auto; padding: 0 24px;
  height: 52px; display: flex; align-items: center; gap: 24px;
}
.site-header .brand { color: var(--fg); font-weight: 600; }
.site-header nav { display: flex; gap: 16px; margin-left: auto; font-size: 14px; }
.site-header nav a { color: var(--fg-muted); }
.site-header nav a:hover, .site-header nav a[aria-current] { color: var(--fg); text-decoration: none; }

/* ---- main ---- */
main { max-width: 760px; margin: 0 auto; padding: 48px 24px 96px; }
.breadcrumb { font-size: 13px; color: var(--fg-muted); margin-bottom: 16px; }
.breadcrumb a { color: var(--fg-muted); }
h1 { font-size: 34px; line-height: 1.25; font-weight: 700; letter-spacing: -.01em; margin: 0 0 8px; }
h2 { font-size: 20px; font-weight: 600; margin: 48px 0 12px; padding-bottom: 6px; border-bottom: 1px solid var(--border); }
h3 { font-size: 16px; font-weight: 600; margin: 24px 0 8px; }
p  { margin: 0 0 16px; }
.lead { color: var(--fg-muted); font-size: 17px; margin-bottom: 40px; }
.meta { color: var(--fg-muted); font-size: 13px; font-family: var(--mono); margin-bottom: 32px; }
ul, ol { padding-left: 1.4em; }
li { margin: 4px 0; }
hr { border: 0; border-top: 1px solid var(--border); margin: 40px 0; }
code { font-family: var(--mono); font-size: .9em; background: var(--bg-subtle); padding: 2px 5px; border-radius: 4px; }
pre { background: var(--bg-subtle); border: 1px solid var(--border); border-radius: var(--radius); padding: 16px; overflow-x: auto; }
pre code { background: none; padding: 0; }
blockquote { margin: 0 0 16px; padding: 4px 0 4px 16px; border-left: 3px solid var(--border); color: var(--fg-muted); }
table { border-collapse: collapse; width: 100%; font-size: 15px; margin: 0 0 16px; }
th, td { text-align: left; padding: 8px 12px; border-bottom: 1px solid var(--border); }
th { font-weight: 600; color: var(--fg-muted); font-size: 13px; }
details { border: 1px solid var(--border); border-radius: var(--radius); padding: 12px 16px; margin: 12px 0; }
summary { cursor: pointer; font-weight: 600; }

/* ---- cards (hub) ---- */
.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 16px; list-style: none; padding: 0; margin: 0; }
.cards li { margin: 0; }
.cards a {
  display: block; height: 100%; padding: 20px 22px;
  border: 1px solid var(--border); border-radius: var(--radius);
  color: var(--fg); transition: border-color .15s, background .15s;
}
.cards a:hover { border-color: var(--accent); background: var(--bg-subtle); text-decoration: none; }
.cards strong { display: block; font-size: 17px; margin-bottom: 4px; }
.cards span { color: var(--fg-muted); font-size: 14px; }

/* ---- entry list ---- */
.entries { list-style: none; padding: 0; margin: 0; border-top: 1px solid var(--border); }
.entries li { margin: 0; border-bottom: 1px solid var(--border); }
.entries a { display: flex; gap: 16px; align-items: baseline; padding: 12px 4px; color: var(--fg); }
.entries a:hover { background: var(--bg-subtle); text-decoration: none; }
.entries time { flex: 0 0 auto; font-family: var(--mono); font-size: 13px; color: var(--fg-muted); }
.entries .title { font-weight: 500; }
.entries .preview { color: var(--fg-muted); font-size: 14px; margin-left: auto; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; max-width: 45%; }
.empty { color: var(--fg-muted); font-size: 15px; padding: 24px 0; }

/* ---- calendar strip (study) ---- */
.calendar { display: grid; grid-template-columns: repeat(7, 1fr); gap: 6px; list-style: none; padding: 0; margin: 0; }
.calendar li { margin: 0; }
.calendar a, .calendar span {
  display: block; text-align: center; padding: 8px 0; font-size: 13px; font-family: var(--mono);
  border: 1px solid var(--border); border-radius: 6px; color: var(--fg);
}
.calendar a { background: var(--accent-soft); border-color: transparent; }
.calendar a:hover { text-decoration: none; border-color: var(--accent); }
.calendar span { color: var(--fg-muted); }

/* ---- misc ---- */
.badge { display: inline-block; font-size: 12px; padding: 1px 8px; border-radius: 999px; background: var(--accent-soft); color: var(--accent); font-weight: 600; vertical-align: middle; }
.note { border: 1px solid var(--border); background: var(--bg-subtle); border-radius: var(--radius); padding: 14px 18px; margin: 16px 0; }
.site-footer { max-width: 760px; margin: 0 auto; padding: 0 24px 48px; color: var(--fg-muted); font-size: 13px; }
.back { display: inline-block; margin-top: 48px; font-size: 14px; }
@media (max-width: 600px) {
  h1 { font-size: 28px; }
  main { padding: 32px 18px 64px; }
  .entries .preview { display: none; }
}