/* ---- Fonts (self-hosted, latin subset) ---- */
@font-face {
  font-family: "IBM Plex Sans";
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url("fonts/ibm-plex-sans-latin-400-normal.woff2") format("woff2");
}
@font-face {
  font-family: "IBM Plex Sans";
  font-style: italic;
  font-weight: 400;
  font-display: swap;
  src: url("fonts/ibm-plex-sans-latin-400-italic.woff2") format("woff2");
}
@font-face {
  font-family: "IBM Plex Sans";
  font-style: normal;
  font-weight: 600;
  font-display: swap;
  src: url("fonts/ibm-plex-sans-latin-600-normal.woff2") format("woff2");
}

/* ---- Design tokens ---- */
:root {
  --accent: #14213d;
  --accent-link: #1c3a6e;
  --text: #1a1a1a;
  --text-muted: #5a5a5a;
  --bg: #ffffff;
  --surface: #faf9f7;
  --border: #e6e3dc;
  --maxw: 760px;
}

/* Dark theme is opt-in via the corner toggle (default is light). */
:root[data-theme="dark"] {
  --accent: #cdd9f0;
  --accent-link: #8fb3f0;
  --text: #e6e6e6;
  --text-muted: #a0a0a0;
  --bg: #14161a;
  --surface: #1b1e24;
  --border: #2a2e36;
}

/* ---- Reset / base ---- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: "IBM Plex Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  font-size: 17px;
  line-height: 1.65;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}
.container { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 1.5rem; }
a { color: var(--accent-link); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; height: auto; display: block; }
strong, b { font-weight: 600; } /* use the loaded semibold face rather than faux-bold */

.skip-link { position: absolute; left: -999px; top: 0; background: var(--accent); color: #fff; padding: 0.5rem 1rem; z-index: 10; }
.skip-link:focus { left: 0; }
:focus-visible { outline: 2px solid var(--accent-link); outline-offset: 2px; }

/* ---- Site nav ---- */
.site-nav { border-bottom: 1px solid var(--border); position: sticky; top: 0; background: var(--bg); z-index: 5; }
.site-nav__inner { display: flex; align-items: center; justify-content: space-between; gap: 1rem; padding-top: 0.9rem; padding-bottom: 0.9rem; }
.site-nav__brand { font-weight: 600; color: var(--accent); font-size: 1.02rem; }
.site-nav__brand:hover { text-decoration: none; }
.site-nav nav { display: flex; gap: 1.15rem; flex-wrap: wrap; }
.site-nav nav a { color: var(--text-muted); font-size: 0.93rem; }
.site-nav nav a:hover { color: var(--text); text-decoration: none; }
.site-nav nav a.is-active { color: var(--accent); font-weight: 600; }

/* ---- Hero ---- */
.hero { padding: 3.5rem 0 2rem; }
.hero__name { margin: 0; font-size: 2.1rem; font-weight: 600; letter-spacing: -0.02em; color: var(--accent); }
.hero__title { margin: 0.15rem 0 0; font-size: 1.05rem; color: var(--text-muted); }
.hero__tagline { margin: 0.9rem 0 0; max-width: 42ch; color: var(--text); }
.hero__contacts { margin-top: 1.4rem; display: flex; flex-wrap: wrap; gap: 0.5rem 1.25rem; align-items: center; }
.hero__contacts a { font-size: 0.95rem; }
.hero__photo { width: 140px; height: 140px; border-radius: 50%; object-fit: cover; border: 1px solid var(--border); margin-bottom: 1.1rem; }

.btn { display: inline-block; padding: 0.5rem 1rem; border: 1px solid var(--accent); border-radius: 8px; color: var(--accent); font-size: 0.9rem; line-height: 1; }
.btn:hover { background: var(--accent); color: var(--bg); text-decoration: none; }

/* ---- Theme toggle (fixed corner button) ---- */
.theme-toggle {
  position: fixed; right: 1rem; bottom: 1rem; z-index: 20;
  width: 42px; height: 42px; border-radius: 50%;
  display: inline-flex; align-items: center; justify-content: center;
  background: var(--surface); color: var(--text);
  border: 1px solid var(--border); cursor: pointer;
  font-size: 18px; line-height: 1;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.12);
}
.theme-toggle:hover { border-color: var(--accent-link); }
.theme-toggle__icon { pointer-events: none; }

/* ---- Page header (secondary pages) ---- */
.page-head { padding: 2.5rem 0 0.5rem; }
.page-head h1 { margin: 0; font-size: 1.7rem; font-weight: 600; color: var(--accent); letter-spacing: -0.02em; }
.page-head p { margin: 0.5rem 0 0; color: var(--text-muted); max-width: 52ch; }

/* ---- Sections ---- */
.section { padding: 1.75rem 0; border-top: 1px solid var(--border); }
.section:first-of-type { border-top: none; }
.section__title { margin: 0 0 1rem; font-size: 0.9rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.08em; color: var(--text-muted); }
.section p { margin: 0 0 0.5rem; }

/* Keep prose at a comfortable reading measure (~66 chars) rather than full width. */
.section p, .entry__points, .paper p { max-width: 68ch; }

/* Skills */
.skills { display: grid; grid-template-columns: 1fr 1fr; gap: 1.25rem 2rem; }
.skills__label { margin: 0 0 0.25rem; font-size: 0.9rem; font-weight: 600; color: var(--accent); }
.skills__list { margin: 0; color: var(--text-muted); font-size: 0.95rem; }

/* ---- Section cards (home → nav into areas) ---- */
.cards { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
.card { display: block; padding: 1.1rem 1.25rem; background: var(--surface); border: 1px solid var(--border); border-radius: 12px; color: inherit; }
.card:hover { text-decoration: none; border-color: var(--accent-link); }
.card__title { font-size: 1.05rem; font-weight: 600; color: var(--accent); }
.card__desc { margin: 0.25rem 0 0; color: var(--text-muted); font-size: 0.93rem; }

/* ---- Experience / education entries ---- */
.entry { margin-bottom: 1.5rem; }
.entry:last-child { margin-bottom: 0; }
.entry__head { display: flex; justify-content: space-between; align-items: baseline; gap: 1rem; flex-wrap: wrap; }
.entry__role { margin: 0; font-size: 1.05rem; font-weight: 600; color: var(--accent); }
.entry__meta { color: var(--text-muted); font-size: 0.9rem; white-space: nowrap; }
.entry__points { margin: 0.5rem 0 0; padding-left: 1.1rem; }
.entry__points li { margin-bottom: 0.3rem; }

/* ---- Projects listing grid ---- */
.project-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 1.25rem; }
.project-card { display: block; background: var(--surface); border: 1px solid var(--border); border-radius: 12px; overflow: hidden; color: inherit; }
.project-card:hover { text-decoration: none; border-color: var(--accent-link); }
.project-card__thumb { width: 100%; aspect-ratio: 16 / 9; object-fit: cover; border-bottom: 1px solid var(--border); }

/* Default project image: swap to the dark variant under the dark theme.
   Scoped to the placeholder src, so real screenshots are never overridden. */
:root[data-theme="dark"] img[src$="placeholder.svg"] { content: url("img/placeholder-dark.svg"); }
.project-card__body { padding: 0.9rem 1.1rem 1.1rem; }
.project-card__name { font-size: 1.05rem; font-weight: 600; color: var(--accent); }
.project-card__desc { margin: 0.3rem 0 0.6rem; color: var(--text-muted); font-size: 0.93rem; }
.tags { display: flex; flex-wrap: wrap; gap: 0.4rem; }
.tag { font-size: 0.78rem; color: var(--text-muted); border: 1px solid var(--border); border-radius: 20px; padding: 0.15rem 0.6rem; }

/* ---- Project detail (case study) ---- */
.back-link { display: inline-block; margin: 1.5rem 0 0; font-size: 0.9rem; }
.case__title { margin: 0.75rem 0 0.25rem; font-size: 1.9rem; font-weight: 600; color: var(--accent); letter-spacing: -0.02em; }
.case__summary { margin: 0; color: var(--text-muted); font-size: 1.05rem; max-width: 55ch; }
.case__meta { display: flex; flex-wrap: wrap; gap: 0.75rem 1.5rem; margin: 1.25rem 0; padding: 1rem 0; border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); font-size: 0.9rem; }
.case__meta dt { color: var(--text-muted); margin: 0; font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.06em; }
.case__meta dd { margin: 0.2rem 0 0; }
.case__cover { width: 100%; border: 1px solid var(--border); border-radius: 12px; margin: 1.5rem 0; }
.case h2 { font-size: 1.15rem; font-weight: 600; margin: 2rem 0 0.6rem; }
.gallery { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; margin-top: 1rem; }
.gallery img { border: 1px solid var(--border); border-radius: 10px; }
.gallery figcaption { font-size: 0.85rem; color: var(--text-muted); margin-top: 0.35rem; }

/* ---- Events list ---- */
.event { display: grid; grid-template-columns: 7.5rem 1fr; gap: 0.5rem 1.25rem; padding: 1.1rem 0; border-top: 1px solid var(--border); }
.event:first-child { border-top: none; }
.event__date { color: var(--text-muted); font-size: 0.9rem; }
.event__name { margin: 0; font-size: 1.05rem; font-weight: 600; color: var(--accent); }
.event__meta { color: var(--text-muted); font-size: 0.88rem; margin: 0.15rem 0 0.4rem; }
.event__desc { margin: 0; color: var(--text); font-size: 0.95rem; }
.badge { display: inline-block; font-size: 0.75rem; font-weight: 600; color: var(--accent); background: var(--surface); border: 1px solid var(--border); border-radius: 20px; padding: 0.1rem 0.55rem; }

/* ---- Papers list ---- */
.paper { padding: 1.1rem 0; border-top: 1px solid var(--border); }
.paper:first-child { border-top: none; }
.paper__title { margin: 0; font-size: 1.02rem; font-weight: 600; color: var(--accent); }
.paper__authors { margin: 0.25rem 0 0; font-size: 0.93rem; color: var(--text); }
.paper__authors .me { font-weight: 600; }
.paper__venue { margin: 0.15rem 0 0.5rem; font-size: 0.9rem; color: var(--text-muted); font-style: italic; }
.paper__links { display: flex; gap: 1rem; font-size: 0.88rem; }

/* ---- Footer ---- */
.footer { padding: 2rem 0 3rem; border-top: 1px solid var(--border); margin-top: 1.5rem; }
.footer p { margin: 0; color: var(--text-muted); font-size: 0.9rem; display: flex; gap: 0.6rem; flex-wrap: wrap; }

/* ---- Responsive ---- */
@media (max-width: 560px) {
  body { font-size: 16px; }
  .hero { padding: 2.25rem 0 1.5rem; }
  .hero__name { font-size: 1.8rem; }
  .skills, .cards, .project-grid, .gallery { grid-template-columns: 1fr; }
  .entry__meta { white-space: normal; }
  .event { grid-template-columns: 1fr; gap: 0.15rem; }
  .site-nav__inner { flex-direction: column; align-items: flex-start; gap: 0.2rem; }
  /* Roomier tap targets on touch: stacked nav links and the CV button. */
  .site-nav nav { gap: 0 1.15rem; }
  .site-nav nav a { padding: 0.45rem 0; }
  .btn { padding: 0.8rem 1.1rem; }
}

/* ---- Touch: guarantee 44px tap targets on coarse pointers ---- */
@media (pointer: coarse) {
  .site-nav nav a,
  .hero__contacts a,
  .paper__links a,
  .footer p a,
  .back-link {
    display: inline-flex;
    align-items: center;
    min-height: 44px;
  }
  .theme-toggle { width: 44px; height: 44px; }
}

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

/* ---- Print ---- */
@media print {
  :root { --bg: #fff; --text: #000; --text-muted: #333; --accent: #14213d; --border: #ccc; --surface: #fff; }
  .site-nav, .btn, .skip-link, .back-link, .theme-toggle { display: none; }
  .section, .hero { padding: 0.8rem 0; }
  a { color: #000; text-decoration: none; }
}