/* ==========================================================================
   base.css — reset, typography, layout primitives, nav/footer, language
   switching, scroll-reveal primitives, accessibility. jankovic.phd
   ========================================================================== */

/* ---- Reset ---- */
*, *::before, *::after { box-sizing: border-box; }
* { margin: 0; }
html { -webkit-text-size-adjust: 100%; }
img, svg, video { display: block; max-width: 100%; }
input, button, textarea, select { font: inherit; color: inherit; }
button { background: none; border: none; padding: 0; cursor: pointer; }

html { scroll-behavior: smooth; scroll-padding-top: calc(var(--nav-height) + 16px); }

body {
  font-family: var(--font-body);
  font-size: var(--text-base);
  line-height: 1.65;
  color: var(--text-body);
  background-color: var(--bg-page);
  background-image: var(--nebula);
  background-attachment: fixed;
  background-repeat: no-repeat;
  background-size: cover;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

main { flex: 1; }

::selection { background: var(--selection-bg); color: var(--selection-text); }

/* ---- Language switching (EN / FR / KO / DE) ----
   Content carries real lang attributes; the html[data-lang] state hides every
   other language. Foreign-language islands that must always show (e.g. a
   French journal name inside English prose) opt out with .keep. */
[data-lang="en"] [lang]:not([lang="en"], .keep) { display: none !important; }
[data-lang="fr"] [lang]:not([lang="fr"], .keep) { display: none !important; }
[data-lang="ko"] [lang]:not([lang="ko"], .keep) { display: none !important; }
[data-lang="de"] [lang]:not([lang="de"], .keep) { display: none !important; }

/* ---- Typography ---- */
h1, h2, h3, h4 {
  font-family: var(--font-display);
  color: var(--text-heading);
  letter-spacing: -0.015em;
  text-wrap: balance;
}
h1 { font-size: var(--text-3xl); line-height: 1.08; font-weight: 700; }
h2 { font-size: var(--text-2xl); line-height: 1.2; font-weight: 700; }
h3 { font-size: var(--text-xl); line-height: 1.3; font-weight: 500; }
h4 { font-size: var(--text-lg); line-height: 1.45; font-weight: 500; }

p { max-width: 65ch; }

a { color: var(--text-link); text-decoration-thickness: 1px; text-underline-offset: 3px;
    transition: color var(--dur-1) var(--ease-out), text-underline-offset var(--dur-1) var(--ease-out); }
a:hover { color: var(--text-link-hover); text-underline-offset: 5px; }

code, pre, .mono { font-family: var(--font-mono); font-size: 0.92em; line-height: 1.55; }

.eyebrow {
  font-family: var(--font-display);
  font-size: var(--text-sm);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-eyebrow);
}

.muted { color: var(--text-muted); }
.small { font-size: var(--text-sm); }

/* ---- Focus / accessibility ---- */
:focus-visible { outline: 2px solid var(--focus-ring); outline-offset: 3px; border-radius: 2px; }
:focus:not(:focus-visible) { outline: none; }

.skip-link {
  position: absolute; left: 16px; top: -64px; z-index: 200;
  padding: 10px 18px; border-radius: var(--radius-btn);
  background: var(--accent-primary); color: var(--text-on-accent);
  font-family: var(--font-display); font-weight: 500; text-decoration: none;
  transition: top var(--dur-2) var(--ease-out);
}
.skip-link:focus { top: 12px; color: var(--text-on-accent); }

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

/* ---- Layout primitives ---- */
.container { max-width: var(--container); margin-inline: auto; padding-inline: clamp(1rem, 4vw, 2.5rem); }

.section { padding-block: var(--space-9); }
@media (max-width: 639px) { .section { padding-block: var(--space-8); } }

.section-head { display: flex; align-items: center; gap: 12px; margin-bottom: var(--space-6); }
.section-head .icon { width: 1.2em; height: 1.2em; font-size: var(--text-2xl); color: var(--text-heading); flex: none; }
.section-head .count { font-family: var(--font-mono); font-size: var(--text-sm); color: var(--text-muted); align-self: center; margin-top: 0.5em; }

/* Divider with mini orbital glyph sitting in a gap of the rule */
.divider { position: relative; height: 21px; margin-inline: auto; max-width: var(--container); padding-inline: clamp(1rem, 4vw, 2.5rem); }
.divider::before, .divider::after {
  content: ""; position: absolute; top: 10px; height: 1px; background: var(--border-hairline);
  width: calc(50% - 34px - clamp(1rem, 4vw, 2.5rem) / 2);
}
.divider::before { left: clamp(1rem, 4vw, 2.5rem); }
.divider::after { right: clamp(1rem, 4vw, 2.5rem); }
.divider .icon { position: absolute; left: 50%; transform: translateX(-50%); width: 20px; height: 20px; color: var(--text-muted); opacity: 0.8; }

/* ---- Icons ---- */
.icon { width: 1em; height: 1em; fill: none; stroke: currentColor; stroke-width: 1.75;
        stroke-linecap: round; stroke-linejoin: round; flex: none; }
.icon--fill { fill: currentColor; stroke: none; }

/* ---- Nav ---- */
.site-nav {
  position: sticky; top: 0; z-index: 100;
  background: var(--bg-page); /* fallback when backdrop-filter unsupported */
  border-bottom: 1px solid transparent;
  transition: border-color var(--dur-2) var(--ease-out);
}
@supports (backdrop-filter: blur(12px)) {
  .site-nav { background: var(--nav-bg); backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px); }
}
.site-nav.is-scrolled { border-bottom-color: var(--border-hairline); }

.site-nav__inner {
  display: flex; align-items: center; gap: var(--space-5);
  min-height: var(--nav-height);
  max-width: var(--container); margin-inline: auto; padding-inline: clamp(1rem, 4vw, 2.5rem);
}

.site-nav__brand {
  display: flex; align-items: center; gap: 10px;
  font-family: var(--font-display); font-weight: 500; font-size: var(--text-base);
  color: var(--text-body); text-decoration: none; white-space: nowrap;
}
.site-nav__brand:hover { color: var(--text-heading); }
.site-nav__brand .icon { width: 24px; height: 24px; color: var(--text-heading); stroke-width: 2; }

.site-nav__links { display: flex; align-items: center; gap: var(--space-4); margin-left: auto; list-style: none; padding: 0; }
.site-nav__link {
  position: relative; display: inline-block; padding: 8px 2px;
  font-family: var(--font-body); font-weight: 500; font-size: var(--text-sm);
  color: var(--text-muted); text-decoration: none; white-space: nowrap;
}
.site-nav__link::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: 2px; height: 2px;
  background: var(--accent-primary); border-radius: 1px;
  transform: scaleX(0); transform-origin: left;
  transition: transform var(--dur-2) var(--ease-out);
}
.site-nav__link:hover { color: var(--text-body); }
.site-nav__link:hover::after { transform: scaleX(1); }
.site-nav__link:not(:hover)::after { transform-origin: right; }
.site-nav__link[aria-current="page"] { color: var(--text-body); }
.site-nav__link[aria-current="page"]::after { transform: scaleX(1); }

.site-nav__controls { display: flex; align-items: center; gap: var(--space-3); padding-left: var(--space-4); border-left: 1px solid var(--border-hairline); }

/* Language segmented pill — four options, flag + code */
.lang-toggle {
  display: inline-flex; border: 1px solid var(--border-strong);
  border-radius: var(--radius-pill); padding: 2px; background: transparent; gap: 2px;
}
.lang-toggle__opt {
  display: inline-flex; align-items: center; gap: 5px;
  padding: 3px 8px; border-radius: var(--radius-pill);
  font-family: var(--font-display); font-weight: 500; font-size: var(--text-xs);
  letter-spacing: 0.02em; color: var(--text-muted);
  transition: color var(--dur-2) var(--ease-out), background-color var(--dur-2) var(--ease-out);
}
.lang-toggle__opt:hover { color: var(--text-body); }
.lang-toggle__opt[aria-pressed="true"] { background: var(--accent-primary); color: var(--text-on-accent); }
.lang-toggle__opt .flag { width: 16px; height: 12px; border-radius: 2px; flex: none;
  box-shadow: 0 0 0 1px rgb(128 128 128 / 0.35); }
@media (max-width: 767px) {
  .lang-toggle__opt { padding: 3px 6px; }
  .lang-toggle__opt .code { display: none; } /* flags only on small screens */
}

/* Theme toggle: sun + moon overlaid */
.theme-toggle {
  position: relative; width: 36px; height: 36px; border-radius: var(--radius-btn);
  color: var(--text-muted); display: inline-grid; place-items: center;
  transition: color var(--dur-2) var(--ease-out), background-color var(--dur-2) var(--ease-out);
}
.theme-toggle:hover { color: var(--text-heading); background: var(--surface-raised); }
.theme-toggle .icon { position: absolute; width: 20px; height: 20px;
  transition: transform var(--dur-3) var(--ease-out), opacity var(--dur-3) var(--ease-out); }
:root[data-theme="dark"] .theme-toggle .icon--sun { transform: rotate(90deg) scale(0.6); opacity: 0; }
:root[data-theme="dark"] .theme-toggle .icon--moon { transform: rotate(0) scale(1); opacity: 1; }
:root[data-theme="light"] .theme-toggle .icon--sun { transform: rotate(0) scale(1); opacity: 1; }
:root[data-theme="light"] .theme-toggle .icon--moon { transform: rotate(-90deg) scale(0.6); opacity: 0; }

/* Theme cross-fade: applied briefly by JS on toggle */
html.theming *, html.theming *::before, html.theming *::after {
  transition: background-color 300ms var(--ease-out), color 300ms var(--ease-out),
              border-color 300ms var(--ease-out), fill 300ms var(--ease-out),
              stroke 300ms var(--ease-out), box-shadow 300ms var(--ease-out) !important;
}

/* Mobile nav: two rows, scrollable pill row — no hamburger */
@media (max-width: 639px) {
  .site-nav__inner { flex-wrap: wrap; row-gap: 0; padding-block: 8px; }
  .site-nav__brand { margin-right: auto; }
  .site-nav__controls { order: 2; border-left: none; padding-left: 0; }
  .site-nav__links {
    order: 3; width: 100%; margin: 0; padding-bottom: 8px;
    overflow-x: auto; scrollbar-width: none;
    -webkit-mask-image: linear-gradient(90deg, transparent, #000 24px, #000 calc(100% - 24px), transparent);
            mask-image: linear-gradient(90deg, transparent, #000 24px, #000 calc(100% - 24px), transparent);
  }
  .site-nav__links::-webkit-scrollbar { display: none; }
  .site-nav__link { padding: 6px 12px; border: 1px solid var(--border-hairline); border-radius: var(--radius-pill); }
  .site-nav__link::after { display: none; }
  .site-nav__link[aria-current="page"] { border-color: var(--accent-primary); color: var(--text-body); }
}

/* ---- Footer ---- */
.site-footer { background: var(--bg-subtle); border-top: 1px solid var(--border-hairline); margin-top: var(--space-8); }
.site-footer__grid {
  display: grid; grid-template-columns: 2fr 1fr 1fr; gap: var(--space-6);
  padding-block: var(--space-8);
}
.site-footer h4 { font-size: var(--text-xs); text-transform: uppercase; letter-spacing: 0.1em; color: var(--text-heading); margin-bottom: var(--space-3); }
.site-footer ul { list-style: none; padding: 0; display: grid; gap: var(--space-2); }
.site-footer a { color: var(--text-muted); text-decoration: none; font-size: var(--text-sm); }
.site-footer a:hover { color: var(--text-link); }
.site-footer__bio { color: var(--text-muted); font-size: var(--text-sm); max-width: 38ch; }
.site-footer__icons { display: flex; gap: var(--space-2); margin-top: var(--space-4); flex-wrap: wrap; }
.site-footer__bottom {
  border-top: 1px solid var(--border-hairline); padding-block: var(--space-4);
  font-family: var(--font-mono); font-size: var(--text-xs); color: var(--text-muted);
  display: flex; justify-content: space-between; gap: var(--space-4); flex-wrap: wrap;
}
@media (max-width: 959px) { .site-footer__grid { grid-template-columns: 1fr 1fr; } }
@media (max-width: 639px) { .site-footer__grid { grid-template-columns: 1fr; } }

/* ---- Scroll reveal (activated only when JS present) ---- */
html.js [data-reveal] {
  opacity: 0; translate: 0 16px;
  transition: opacity var(--dur-4) var(--ease-out), translate var(--dur-4) var(--ease-out);
  transition-delay: var(--reveal-delay, 0ms);
}
html.js [data-reveal].is-in { opacity: 1; translate: 0 0; }

/* Page-load hero stagger (CSS only; .is-loaded added on DOMContentLoaded) */
html.js .load-rise { opacity: 0; translate: 0 20px;
  transition: opacity var(--dur-4) var(--ease-out), translate var(--dur-4) var(--ease-out);
  transition-delay: var(--load-delay, 0ms); }
html.js body.is-loaded .load-rise { opacity: 1; translate: 0 0; }

/* Cross-document view transitions (progressive enhancement) */
@view-transition { navigation: auto; }
::view-transition-old(root), ::view-transition-new(root) { animation-duration: 180ms; }

/* ---- Back to top ---- */
.back-to-top {
  position: fixed; right: 24px; bottom: 24px; z-index: 90;
  width: 44px; height: 44px; border-radius: 50%;
  background: var(--surface-raised); border: 1px solid var(--border-strong);
  color: var(--text-heading); display: grid; place-items: center;
  opacity: 0; translate: 0 12px; pointer-events: none;
  transition: opacity var(--dur-2) var(--ease-out), translate var(--dur-2) var(--ease-out);
}
.back-to-top.is-visible { opacity: 1; translate: 0 0; pointer-events: auto; }
.back-to-top .icon { width: 20px; height: 20px; }
@media (hover: hover) { .back-to-top:hover { translate: 0 -2px; } }
@media (max-width: 639px) { .back-to-top { width: 40px; height: 40px; right: 16px; bottom: 16px; } }

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

/* ---- Print ---- */
@media print {
  .site-nav, .site-footer, .back-to-top, .skip-link { display: none !important; }
  body { background: #fff; color: #111517; }
}