/* ==========================================================================
   Temel katman — sıfırlama, tipografi varsayılanları, düzen ilkelleri.
   Bölüme özgü hiçbir kural burada yer almaz (bkz. app.css).
   ========================================================================== */

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  /* Yapışkan başlık, hedefin üstünü kesmesin */
  scroll-padding-top: 5.5rem;
}

body,
h1, h2, h3, h4, h5, h6,
p, figure, blockquote, dl, dd,
ul, ol { margin: 0; }

ul[class], ol[class] { list-style: none; padding: 0; }

body {
  min-height: 100svh;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font-sans);
  font-size: var(--t-base);
  line-height: var(--lh-body);
  font-synthesis-weight: none;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
  transition: background var(--dur) var(--ease-out),
              color var(--dur) var(--ease-out);
}

img, picture, svg, video {
  display: block;
  max-width: 100%;
  height: auto;
}

input, button, textarea, select { font: inherit; color: inherit; }
button { background: none; border: 0; padding: 0; cursor: pointer; }

a {
  color: inherit;
  text-decoration: none;
}

:where(a, button, input, textarea, select, [tabindex]):focus-visible {
  outline: 2px solid var(--signal);
  outline-offset: 3px;
  border-radius: var(--r-sm);
}

::selection {
  background: var(--signal);
  color: var(--signal-ink);
}

hr {
  border: 0;
  border-top: 1px solid var(--line);
  margin: 0;
}

/* --- Tipografi ölçekleri -------------------------------------------------- */

.u-display {
  font-family: var(--font-display);
  font-weight: 600;
  line-height: var(--lh-tight);
  letter-spacing: var(--tr-tight);
  font-variation-settings: 'opsz' 72;
  text-wrap: balance;
}

.u-mono {
  font-family: var(--font-mono);
  font-size: var(--t-sm);
  font-weight: 400;
  letter-spacing: 0.01em;
  font-variant-numeric: tabular-nums;
}

/* Bölüm üstü küçük etiket — mono, aralıklı, sinyal renginde nokta ile */
.u-label {
  font-family: var(--font-mono);
  font-size: var(--t-xs);
  font-weight: 500;
  letter-spacing: var(--tr-wide);
  text-transform: uppercase;
  color: var(--fg-faint);
  display: inline-flex;
  align-items: center;
  gap: var(--s-2);
}

.u-label::before {
  content: '';
  width: 6px;
  height: 6px;
  flex: none;
  border-radius: 50%;
  background: var(--signal);
}

.u-prose {
  max-width: var(--prose-max);
  color: var(--fg-muted);
  font-size: var(--t-md);
  line-height: var(--lh-loose);
  text-wrap: pretty;
}

.u-muted { color: var(--fg-muted); }
.u-faint { color: var(--fg-faint); }

/* --- Düzen ilkelleri ------------------------------------------------------ */

.wrap {
  width: 100%;
  max-width: var(--page-max);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section {
  position: relative;
  padding-block: var(--section-y);
}

/* Bölümler arası ince ayraç — pano hissini veren yatay çizgi */
.section + .section::before {
  content: '';
  position: absolute;
  inset-inline: var(--gutter);
  top: 0;
  height: 1px;
  background: var(--line);
}

.section__head {
  display: grid;
  gap: var(--s-4);
  margin-bottom: var(--s-8);
}

@media (min-width: 60rem) {
  .section__head {
    grid-template-columns: minmax(0, 1fr) minmax(0, 26rem);
    align-items: end;
    gap: var(--s-7);
  }
}

.section__title {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: var(--t-2xl);
  line-height: var(--lh-tight);
  letter-spacing: var(--tr-tight);
  font-variation-settings: 'opsz' 64;
  text-wrap: balance;
}

.section__note {
  color: var(--fg-muted);
  font-size: var(--t-md);
  line-height: var(--lh-loose);
  text-wrap: pretty;
}

/* --- Erişilebilirlik ------------------------------------------------------ */

.visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
}

.skip-link {
  position: absolute;
  top: var(--s-3);
  left: var(--s-3);
  z-index: var(--z-overlay);
  padding: var(--s-3) var(--s-4);
  background: var(--signal);
  color: var(--signal-ink);
  font-family: var(--font-mono);
  font-size: var(--t-sm);
  border-radius: var(--r-sm);
  transform: translateY(-160%);
  transition: transform var(--dur-fast) var(--ease-out);
}
.skip-link:focus-visible { transform: translateY(0); }

/* --- Hareket tercihi ------------------------------------------------------ */

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}