/* Sistem yazı tipi; dış kaynak yok. Boyutlar rem: tarayıcı yazı boyutuna uyar. */
:root {
  --bg: #ffffff;
  --fg: #1a1a1a;
  --muted: #4a4a4a;
  --link: #0a4fb8;
  --accent: #0a4fb8;
  --accent-fg: #ffffff;
  --card: #f4f5f7;
  --border: #c9ccd1;
  --focus: #b3261e;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #121212;
    --fg: #f0f0f0;
    --muted: #c4c4c4;
    --link: #8ab4ff;
    --accent: #8ab4ff;
    --accent-fg: #0b1a33;
    --card: #1e1f22;
    --border: #44474d;
    --focus: #ffb4ab;
  }
}

*, *::before, *::after { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 1.0625rem/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

main, .site-header nav, .site-footer {
  max-width: 44rem;
  margin: 0 auto;
  padding: 0 1rem;
}

main { padding-bottom: 3rem; }
main:focus { outline: none; }

h1, h2, h3 { line-height: 1.25; }
h1 { font-size: 2rem; margin: 1.5rem 0 .5rem; }
h2 { font-size: 1.5rem; margin: 2.5rem 0 .75rem; padding-top: .5rem; border-top: 1px solid var(--border); }
h3 { font-size: 1.2rem; margin: 1.75rem 0 .5rem; }

a { color: var(--link); text-underline-offset: .15em; }
a:hover { text-decoration-thickness: 2px; }

:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 2px;
  border-radius: 2px;
}

.skip {
  position: absolute;
  left: 1rem;
  top: -10rem;
  padding: .5rem 1rem;
  background: var(--accent);
  color: var(--accent-fg);
  z-index: 10;
}
.skip:focus { top: .5rem; }

.visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px;
  margin: -1px; padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

.site-header { border-bottom: 1px solid var(--border); }
.site-header nav {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem 1.5rem;
  align-items: center;
  min-height: 3.5rem;
}
.site-header a { padding: .5rem 0; }
.brand { font-weight: 600; color: var(--fg); text-decoration: none; }
.brand:hover { text-decoration: underline; }
.site-header .lang { margin-inline-start: auto; }

.lead { font-size: 1.2rem; color: var(--muted); }
.subtitle { color: var(--muted); margin-top: 0; }

.app-list { list-style: none; padding: 0; margin: 0; display: grid; gap: 1rem; }
.app-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: .75rem;
  padding: .25rem 1.25rem .75rem;
}
.app-card h3 { margin-top: .75rem; }

.facts { display: grid; gap: .25rem; margin: 1rem 0; }
.facts div { display: flex; flex-wrap: wrap; gap: 0 .5rem; }
.facts dt { font-weight: 600; }
.facts dt::after { content: ":"; }
.facts dd { margin: 0; }

.actions { list-style: none; padding: 0; display: flex; flex-wrap: wrap; gap: .75rem 1.25rem; align-items: center; }
.actions a { display: inline-block; padding: .5rem 0; min-height: 2.75rem; }
.button {
  background: var(--accent);
  color: var(--accent-fg) !important;
  text-decoration: none;
  border-radius: .5rem;
  padding: .6rem 1.1rem !important;
  font-weight: 600;
}
.button:hover { text-decoration: underline; }

.toc { background: var(--card); border: 1px solid var(--border); border-radius: .75rem; padding: .5rem 1.25rem; }
.toc ol { margin: .25rem 0 .75rem; padding-left: 1.5rem; }
.toc li { margin: .3rem 0; }

details {
  border: 1px solid var(--border);
  border-radius: .5rem;
  padding: .25rem 1rem;
  margin: 1rem 0;
}
summary { cursor: pointer; font-weight: 600; padding: .5rem 0; min-height: 2.75rem; }
details[open] summary { margin-bottom: .25rem; }

.top { font-size: .95rem; }

.site-footer { border-top: 1px solid var(--border); color: var(--muted); padding-top: 1rem; padding-bottom: 2rem; font-size: .95rem; }

@media (prefers-reduced-motion: no-preference) {
  html { scroll-behavior: smooth; }
}