/* koray-erkan.com — "technical manual" layout: headings sit in the left margin
   (side heads) on wide screens and fold back above the text on narrow ones. */

:root {
  --paper: #f7f8fa;
  --ink: #1a2330;
  --muted: #5a6573;
  --rule: #d8dde4;
  --accent: #0b5394;
  --accent-soft: #e3ecf6;

  --sans: "Public Sans", system-ui, sans-serif;
  --serif: "Literata", Georgia, serif;

  --measure: 36rem;   /* text column, ~70 characters */
  --margin: 11rem;    /* side-head column */
  --gap: 2.5rem;
}
:root[data-theme="dark"] { color-scheme: dark; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #12171e;
    --ink: #e2e7ee;
    --muted: #97a3b2;
    --rule: #2c3540;
    --accent: #83b6ee;
    --accent-soft: #1b2939;
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 400 1.0625rem/1.7 var(--serif);
  font-optical-sizing: auto;
}

/* Page frame: margin column + text column, left-aligned like a manual page. */
.masthead, .page, .colophon {
  max-width: calc(var(--margin) + var(--gap) + var(--measure));
  margin: 0 auto;
  padding: 0 1rem;
}
@media (min-width: 60rem) {
  .masthead, .page, .colophon {
    max-width: calc(var(--margin) + var(--gap) + var(--measure) + 4rem);
    padding: 0 2rem;
  }
}

a { color: var(--accent); text-underline-offset: .18em; text-decoration-thickness: 1px; }
a:hover { text-decoration-thickness: 2px; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 2px; }

.skip { position: absolute; left: -999px; }
.skip:focus { left: 1rem; top: 1rem; background: var(--paper); padding: .5rem 1rem; z-index: 1; }

/* Masthead */
.masthead {
  display: flex; flex-wrap: wrap; align-items: baseline; justify-content: space-between;
  gap: .5rem 1.5rem;
  padding-top: 1.75rem; padding-bottom: 1.75rem;
  font-family: var(--sans);
}
.brand { font-weight: 800; color: var(--ink); text-decoration: none; letter-spacing: -.01em; }
nav { display: flex; gap: 1.25rem; }
nav a { color: var(--muted); text-decoration: none; font-size: .95rem; }
nav a:hover, nav a[aria-current="page"] { color: var(--ink); }
nav a[aria-current="page"] { box-shadow: inset 0 -2px var(--accent); }

/* Headings */
h1, h2, h3 { font-family: var(--sans); line-height: 1.2; color: var(--ink); }
h1 { font-size: 2.25rem; font-weight: 800; letter-spacing: -.02em; margin: 0 0 1rem; }
h2 { font-size: 1rem; font-weight: 600; margin: 3rem 0 .75rem; color: var(--accent); }
h3 { font-size: 1.125rem; font-weight: 600; margin: 1.75rem 0 .25rem; }
h3 + p { margin-top: 0; }
p, ul, ol { margin: 0 0 1rem; }

/* Hero: the name large, set flush with the text column. */
.hero { padding: 3rem 0 2rem; border-top: 1px solid var(--rule); }
.hero h1 { font-size: clamp(2.5rem, 7vw, 4.25rem); line-height: 1; letter-spacing: -.035em; margin: 0 0 1.25rem; }
.lede { font-size: 1.3rem; line-height: 1.5; max-width: 32rem; margin: 0; }

/* Side heads: on wide screens the text column is indented and each h2 is
   floated into the margin. A float starts level with the text beside it, so
   the gap between sections goes on whatever comes *before* the h2. */
@media (min-width: 60rem) {
  .hero, .doc { padding-left: calc(var(--margin) + var(--gap)); }
  .doc > h2 {
    float: left; clear: left;
    width: var(--margin);
    margin: .3rem 0 0 calc(-1 * (var(--margin) + var(--gap)));
    text-align: right;
  }
  .doc > h2 + * { margin-top: 0; }
  .doc > :has(+ h2) { margin-bottom: 3rem; }
}
.doc { max-width: calc(var(--margin) + var(--gap) + var(--measure)); padding-bottom: 3rem; }
.doc > h1 { margin-top: 2.5rem; }

/* Lists of posts */
.posts { list-style: none; padding: 0; }
.posts li { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 0 1rem;
            padding: .6rem 0; border-bottom: 1px solid var(--rule); }
.posts li:first-child { border-top: 1px solid var(--rule); }
time, .meta { font-family: var(--sans); color: var(--muted); font-size: .875rem; }

/* Prose details */
ul { padding-left: 1.2rem; }
li { margin: .25rem 0; }
code { font-size: .9em; background: var(--accent-soft); padding: .1em .3em; border-radius: 3px; }
pre { overflow-x: auto; padding: 1rem; background: var(--accent-soft); border-radius: 4px; line-height: 1.5; }
pre code { background: none; padding: 0; }
blockquote { margin: 1.5rem 0; padding-left: 1rem; border-left: 3px solid var(--accent); color: var(--muted); }

/* Colophon */
.colophon { font-family: var(--sans); font-size: .9rem; color: var(--muted);
            padding-top: 1.5rem; padding-bottom: 3rem; }
.colophon p:first-child { display: flex; flex-wrap: wrap; gap: .5rem 1.5rem;
                          padding-top: 1.5rem; border-top: 1px solid var(--rule); }
.small { font-size: .8rem; }

@media (max-width: 30rem) {
  body { font-size: 1rem; }
  .lede { font-size: 1.15rem; }
}