/* ==========================================================================
   enhancements.css — portable UI layer on top of style.css
   Dark-mode toggle · scroll progress · FABs · search palette · states ·
   loading utilities. All colours read the tokens already defined in style.css.
   ========================================================================== */

/* ---- Scroll progress bar (fixed, above the header) ---- */
.scroll-progress{
  position:fixed;top:0;left:0;right:0;height:3px;z-index:60;
  transform:scaleX(0);transform-origin:0 50%;
  background:linear-gradient(90deg,var(--accent),var(--iso));
  will-change:transform;transition:transform .08s linear;pointer-events:none;
}
@media (prefers-reduced-motion:reduce){.scroll-progress{transition:none}}

/* ---- Header gains a shadow once the page is scrolled ---- */
.site-header{transition:box-shadow .25s ease,background .25s ease}
.site-header.scrolled{box-shadow:0 1px 0 var(--line),0 6px 24px rgba(20,32,31,.10)}
:root[data-theme="dark"] .site-header.scrolled,
:root:not([data-theme="light"]) .site-header.scrolled{box-shadow:0 1px 0 var(--line),0 8px 28px rgba(0,0,0,.5)}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]) .site-header.scrolled{box-shadow:0 1px 0 var(--line),0 8px 28px rgba(0,0,0,.5)}}

/* ---- Icon buttons in the nav (theme toggle, search) ---- */
.icon-btn{
  display:inline-grid;place-items:center;width:40px;height:40px;flex:none;
  background:transparent;border:1px solid var(--line);border-radius:10px;color:var(--ink);
  cursor:pointer;transition:background .15s ease,border-color .15s ease,transform .1s ease,color .15s ease;
}
.icon-btn svg{width:19px;height:19px}
.icon-btn:hover{background:var(--surface-2);border-color:var(--accent);color:var(--accent-ink)}
.icon-btn:focus-visible{outline:2px solid var(--accent);outline-offset:2px}
.icon-btn:active{transform:scale(.92)}
.nav-utils{display:flex;align-items:center;gap:8px}
@media (min-width:861px){
  .nav-links{margin-left:auto}
  .nav-utils{margin-left:14px}
}
@media (max-width:860px){
  .nav-utils{margin-left:auto;margin-right:8px}
}
.search-btn .kbd{
  display:none;margin-left:2px;font-family:"IBM Plex Mono",monospace;font-size:10px;
  color:var(--muted);border:1px solid var(--line);border-radius:4px;padding:1px 5px;
}

/* theme toggle: show the icon for the theme you'll switch TO
   (light now -> moon "go dark"; dark now -> sun "go light") */
.theme-toggle .i-sun{display:none}
.theme-toggle .i-moon{display:block}
:root[data-theme="dark"] .theme-toggle .i-moon{display:none}
:root[data-theme="dark"] .theme-toggle .i-sun{display:block}
@media (prefers-color-scheme:dark){
  :root:not([data-theme="light"]) .theme-toggle .i-moon{display:none}
  :root:not([data-theme="light"]) .theme-toggle .i-sun{display:block}
}

/* ---- Global active/press feedback on interactive elements ---- */
.btn:active{transform:translateY(0) scale(.97)}
.fab:active{transform:scale(.92)}
a:active{opacity:.85}

/* ---- Floating action buttons (bottom-right) ---- */
.fab-stack{position:fixed;right:20px;bottom:20px;z-index:55;display:flex;flex-direction:column;gap:12px;align-items:flex-end}
.fab{
  width:50px;height:50px;border-radius:50%;border:0;cursor:pointer;display:grid;place-items:center;
  color:#fff;box-shadow:var(--shadow-md);transition:transform .15s ease,background .15s ease,opacity .2s ease,visibility .2s ease;
}
.fab svg{width:22px;height:22px}
.fab-contact{background:var(--primary)}
:root[data-theme="dark"] .fab-contact,
:root:not([data-theme="light"]) .fab-contact{color:#06201d}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]) .fab-contact{color:#06201d}}
.fab-contact:hover{background:var(--accent-ink)}
.fab-top{background:var(--surface);color:var(--ink);border:1px solid var(--line)}
.fab-top:hover{background:var(--surface-2);color:var(--accent-ink)}
.fab:focus-visible{outline:2px solid var(--accent);outline-offset:3px}
/* scroll-to-top hidden until scrolled */
.fab-top{opacity:0;visibility:hidden;transform:translateY(8px)}
.fab-top.show{opacity:1;visibility:visible;transform:none}

/* contact popover */
.fab-pop{
  position:absolute;right:0;bottom:62px;min-width:210px;background:var(--surface);
  border:1px solid var(--line);border-radius:14px;box-shadow:var(--shadow-md);padding:8px;
  opacity:0;visibility:hidden;transform:translateY(8px) scale(.98);transform-origin:bottom right;
  transition:opacity .18s ease,transform .18s ease,visibility .18s ease;
}
.fab-pop.open{opacity:1;visibility:visible;transform:none}
.fab-pop a{
  display:flex;align-items:center;gap:11px;padding:10px 12px;border-radius:9px;
  color:var(--ink);font-size:14px;font-weight:500;transition:background .12s ease;
}
.fab-pop a:hover{background:var(--surface-2);color:var(--accent-ink)}
.fab-pop a svg{width:17px;height:17px;color:var(--accent);flex:none}
.fab-pop .pop-head{font-family:"IBM Plex Mono",monospace;font-size:11px;letter-spacing:.08em;
  text-transform:uppercase;color:var(--muted);padding:6px 12px 8px}

/* ---- Search / command palette ---- */
.search-overlay{
  position:fixed;inset:0;z-index:70;background:rgba(10,17,16,.55);backdrop-filter:blur(3px);
  display:flex;align-items:flex-start;justify-content:center;padding:12vh 20px 20px;
  opacity:0;visibility:hidden;transition:opacity .18s ease,visibility .18s ease;
}
.search-overlay.open{opacity:1;visibility:visible}
.search-box{
  width:100%;max-width:600px;background:var(--surface);border:1px solid var(--line);
  border-radius:16px;box-shadow:var(--shadow-md);overflow:hidden;transform:translateY(-8px);
  transition:transform .18s ease;
}
.search-overlay.open .search-box{transform:none}
.search-head{display:flex;align-items:center;gap:12px;padding:16px 18px;border-bottom:1px solid var(--line)}
.search-head svg{width:20px;height:20px;color:var(--muted);flex:none}
.search-head input{
  flex:1;border:0;background:transparent;color:var(--ink);font-size:16px;
  font-family:inherit;outline:none;
}
.search-head input::placeholder{color:var(--muted)}
.search-head .esc{font-family:"IBM Plex Mono",monospace;font-size:11px;color:var(--muted);
  border:1px solid var(--line);border-radius:5px;padding:2px 7px}
.search-results{max-height:52vh;overflow-y:auto;padding:8px}
.search-results a{
  display:flex;align-items:center;gap:12px;padding:12px 14px;border-radius:10px;
  color:var(--ink);text-decoration:none;
}
.search-results a .r-ico{width:32px;height:32px;border-radius:8px;background:var(--accent-soft);
  color:var(--accent-ink);display:grid;place-items:center;flex:none}
.search-results a .r-ico svg{width:16px;height:16px}
.search-results a .r-txt{min-width:0}
.search-results a .r-title{font-weight:600;font-size:14.5px}
.search-results a .r-sub{font-size:12.5px;color:var(--muted)}
.search-results a:hover,.search-results a.active{background:var(--surface-2)}
.search-empty{padding:26px 16px;text-align:center;color:var(--muted);font-size:14px}
.search-foot{display:flex;gap:16px;padding:10px 18px;border-top:1px solid var(--line);
  font-size:11.5px;color:var(--muted);font-family:"IBM Plex Mono",monospace}
.search-foot kbd{border:1px solid var(--line);border-radius:4px;padding:1px 5px;background:var(--surface-2)}

/* ---- Loading utilities (available for future dynamic content) ---- */
.skeleton{
  background:linear-gradient(90deg,var(--surface-2) 25%,var(--line) 37%,var(--surface-2) 63%);
  background-size:400% 100%;border-radius:8px;animation:skeleton 1.4s ease infinite;
}
@keyframes skeleton{0%{background-position:100% 50%}100%{background-position:0 50%}}
.spinner{
  width:22px;height:22px;border-radius:50%;border:2.5px solid var(--line);
  border-top-color:var(--accent);animation:spin .7s linear infinite;display:inline-block;
}
@keyframes spin{to{transform:rotate(360deg)}}
@media (prefers-reduced-motion:reduce){.skeleton,.spinner{animation:none}}

/* subtle first-paint settle for the hero (visible at rest; no hidden content) */
@media (prefers-reduced-motion:no-preference){
  .hero-copy>*{animation:rise .5s ease both}
  .hero-copy>*:nth-child(2){animation-delay:.04s}
  .hero-copy>*:nth-child(3){animation-delay:.08s}
  .hero-copy>*:nth-child(4){animation-delay:.12s}
  @keyframes rise{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:none}}
}

/* ---- Conferences & presenting gallery (extensible) ---- */
.events-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(270px,1fr));gap:16px;margin-top:6px}
.event-card{
  margin:0;background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);
  overflow:hidden;box-shadow:var(--shadow-sm);transition:transform .16s ease,box-shadow .16s ease;
}
.event-card:hover{transform:translateY(-3px);box-shadow:var(--shadow-md)}
.event-card img{width:100%;height:auto;aspect-ratio:3/2;object-fit:cover;display:block;background:var(--surface-2)}
.event-cap{padding:14px 16px}
.event-cap .t{display:block;font-weight:600;font-size:14.5px;color:var(--ink)}
.event-cap .s{display:block;margin-top:5px;font-family:"IBM Plex Mono",monospace;font-size:11px;
  letter-spacing:.04em;text-transform:uppercase;color:var(--muted)}

.event-card{cursor:pointer}
.event-card:focus-visible{outline:2px solid var(--accent);outline-offset:3px}
.event-card .event-cap .zoom{
  float:right;color:var(--accent);opacity:.7;transition:opacity .15s ease;
}
.event-card:hover .event-cap .zoom{opacity:1}
.event-card .zoom svg{width:15px;height:15px;vertical-align:-2px}

/* ---- Photo lightbox ---- */
.lightbox{
  position:fixed;inset:0;z-index:80;background:rgba(8,14,13,.93);backdrop-filter:blur(2px);
  display:flex;align-items:center;justify-content:center;padding:44px 20px;
  opacity:0;visibility:hidden;transition:opacity .2s ease,visibility .2s ease;
}
.lightbox.open{opacity:1;visibility:visible}
.lb-figure{margin:0;display:flex;flex-direction:column;gap:14px;max-width:min(1040px,94vw)}
.lb-figure img{
  max-width:100%;max-height:78vh;object-fit:contain;border-radius:10px;
  box-shadow:0 24px 70px rgba(0,0,0,.55);background:#0b1110;
}
.lb-cap{text-align:center}
.lb-cap .t{display:block;font-weight:600;font-size:16px;color:#eef2ef}
.lb-cap .s{display:block;margin-top:5px;font-family:"IBM Plex Mono",monospace;font-size:11.5px;
  letter-spacing:.05em;text-transform:uppercase;color:#9fb0ab}
.lb-btn{
  position:fixed;display:grid;place-items:center;width:46px;height:46px;border-radius:50%;
  background:rgba(255,255,255,.12);border:1px solid rgba(255,255,255,.22);color:#fff;cursor:pointer;
  transition:background .15s ease,transform .12s ease;
}
.lb-btn:hover{background:rgba(255,255,255,.24)}
.lb-btn:active{transform:scale(.92)}
.lb-btn:focus-visible{outline:2px solid #fff;outline-offset:2px}
.lb-btn svg{width:22px;height:22px}
.lb-close{top:18px;right:18px}
.lb-prev{left:16px;top:50%;margin-top:-23px}
.lb-next{right:16px;top:50%;margin-top:-23px}
@media (max-width:600px){
  .lb-prev{left:10px}.lb-next{right:10px}
  .lb-btn{width:42px;height:42px}
}
@media print{.lightbox{display:none!important}}

/* ---- Credential: certificate thumbnail + link ---- */
.cred .cert-thumb{
  display:block;max-width:230px;margin-top:12px;border:1px solid var(--line);border-radius:10px;
  overflow:hidden;box-shadow:var(--shadow-sm);transition:transform .16s ease,box-shadow .16s ease;
}
.cred .cert-thumb:hover{transform:translateY(-2px);box-shadow:var(--shadow-md)}
.cred .cert-thumb img{display:block;width:100%;height:auto}
.cred .cert-link{display:inline-flex;align-items:center;gap:7px;margin-top:10px;font-size:13px;font-weight:600}
.cred .cert-link svg{width:15px;height:15px}

/* ---- Footer last-updated ---- */
.footer-meta{font-family:"IBM Plex Mono",monospace;font-size:12px;color:var(--muted)}

/* ---- Print: hide all the new chrome ---- */
@media print{
  .scroll-progress,.fab-stack,.search-overlay,.nav-utils,.icon-btn{display:none!important}
  .hero-copy>*{animation:none!important}
}

/* ---- Mobile ---- */
@media (max-width:860px){
  .search-btn .kbd{display:none}
  .fab-stack{right:16px;bottom:16px}
}
@media (min-width:861px){
  .search-btn{display:inline-flex;align-items:center;width:auto;padding:0 12px;gap:8px}
  .search-btn .kbd{display:inline-block}
}