/* ===========================================================
   Yassir EL ATTAR — NLP/AI Research Portfolio
   Academic · minimalist · mobile-first · WCAG AA
   =========================================================== */

:root {
  /* Palette */
  --bg:        #FBFAF8;  /* warm off-white base */
  --bg-alt:    #F2F0EB;  /* alternating section band */
  --ink:       #1C2024;  /* primary text */
  --ink-soft:  #4A5159;  /* secondary text */
  --line:      #DBD8D1;  /* hairline rules */
  --accent:    #1D5C82;  /* research blue */
  --accent-dk: #154763;  /* hover / pressed */
  --accent-bg: #EAF1F5;  /* pale blue tint */

  /* Type */
  --serif: "Spectral", Georgia, serif;
  --sans:  "Inter", system-ui, sans-serif;
  --mono:  "IBM Plex Mono", ui-monospace, monospace;

  /* Rhythm */
  --maxw: 64rem;
  --pad: 1.25rem;
}

/* ---------- Reset / base ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 1rem;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3 { font-family: var(--serif); font-weight: 600; line-height: 1.15; margin: 0; }
p { margin: 0 0 1rem; }
a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-dk); text-decoration: underline; }

img { max-width: 100%; height: auto; display: block; }

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

.skip-link {
  position: absolute; left: -999px; top: 0;
  background: var(--accent); color: #fff;
  padding: .6rem 1rem; z-index: 200;
}
.skip-link:focus { left: 0; }

/* ---------- Shared bits ---------- */
.eyebrow {
  font-family: var(--mono);
  font-size: .75rem;
  letter-spacing: .06em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 1rem;
}

.btn {
  display: inline-block;
  font-family: var(--sans);
  font-weight: 500;
  font-size: .95rem;
  padding: .7rem 1.4rem;
  border-radius: 4px;
  border: 1.5px solid var(--accent);
  transition: background .18s ease, color .18s ease, border-color .18s ease;
}
.btn:hover { text-decoration: none; }
.btn--primary { background: var(--accent); color: #fff; }
.btn--primary:hover { background: var(--accent-dk); border-color: var(--accent-dk); color: #fff; }
.btn--ghost { background: transparent; color: var(--accent); }
.btn--ghost:hover { background: var(--accent-bg); color: var(--accent-dk); }

/* ---------- Header / Nav ---------- */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: color-mix(in srgb, var(--bg) 92%, transparent);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}
.nav {
  max-width: var(--maxw); margin: 0 auto;
  padding: .85rem var(--pad);
  display: flex; align-items: center; justify-content: space-between;
  flex-wrap: wrap;
}
.nav__brand {
  font-family: var(--serif); font-weight: 600; font-size: 1.05rem;
  color: var(--ink);
}
.nav__brand:hover { color: var(--accent); text-decoration: none; }

.nav__checkbox { display: none; }
.nav__burger {
  display: flex; flex-direction: column; gap: 5px;
  width: 28px; cursor: pointer; padding: 4px;
}
.nav__burger span {
  height: 2px; background: var(--ink); border-radius: 2px;
  transition: transform .2s ease, opacity .2s ease;
}

.nav__links {
  list-style: none; margin: 0; padding: 0;
  display: none; width: 100%;
  flex-direction: column; gap: .25rem;
  margin-top: .75rem;
}
.nav__checkbox:checked ~ .nav__links { display: flex; }
.nav__links a {
  display: block;
  font-family: var(--mono); font-size: .85rem;
  color: var(--ink-soft); padding: .5rem 0;
}
.nav__links a:hover { color: var(--accent); text-decoration: none; }

/* ---------- Layout helpers ---------- */
.hero, .section {
  max-width: var(--maxw); margin: 0 auto;
  padding: 3.5rem var(--pad);
}
.section--alt {
  max-width: none;
  background: var(--bg-alt);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.section--alt > * { } /* inner padding handled below */
.section--alt .section__head,
.section--alt .projects,
.section--alt .cv,
.section--alt .contact-list {
  max-width: var(--maxw); margin-left: auto; margin-right: auto;
}

/* ---------- Hero ---------- */
.hero { padding-top: 4.5rem; padding-bottom: 4rem; }
.hero__title {
  font-size: clamp(2rem, 6.5vw, 3.25rem);
  letter-spacing: -0.01em;
  margin-bottom: 1.25rem;
  max-width: 18ch;
}
.hero__lede {
  font-size: 1.1rem; color: var(--ink-soft);
  max-width: 56ch; margin-bottom: 2rem;
}
.hero__actions { display: flex; flex-wrap: wrap; gap: .75rem; }
.hero__links {
  font-family: var(--mono); font-size: .85rem; margin: 0;
  display: flex; flex-wrap: wrap; align-items: center; gap: .15rem .6rem;
}
.hero__links span { color: var(--line); }

/* ---------- Section heads ---------- */
.section__head { margin-bottom: 2.5rem; }
.section__title {
  font-size: clamp(1.6rem, 4.5vw, 2.2rem);
  margin-bottom: .75rem;
}
.section__intro { color: var(--ink-soft); max-width: 60ch; margin: 0; }
.section__note {
  margin-top: 2rem; padding: 1rem 1.25rem;
  background: var(--accent-bg); border-left: 3px solid var(--accent);
  font-size: .9rem; color: var(--ink-soft); border-radius: 0 4px 4px 0;
}

/* ---------- Publications ---------- */
.pub-list { list-style: none; margin: 0; padding: 0; }
.pub {
  padding: 1.5rem 0;
  border-top: 1px solid var(--line);
}
.pub:first-child { border-top: none; padding-top: 0; }
.pub__venue {
  font-family: var(--mono); font-size: .75rem; letter-spacing: .04em;
  text-transform: uppercase; color: var(--ink-soft); margin: 0 0 .4rem;
}
.pub__title { font-size: 1.25rem; margin-bottom: .4rem; }
.pub__authors { font-size: .95rem; margin-bottom: .5rem; }
.pub__abstract { color: var(--ink-soft); font-size: .95rem; margin-bottom: .6rem; }
.pub__links { font-family: var(--mono); font-size: .82rem; margin: 0; }
.pub__links span { color: var(--line); margin: 0 .5rem; }

/* ---------- Projects ---------- */
.projects { display: grid; grid-template-columns: 1fr; gap: 1.25rem; }
.card {
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 1.5rem;
  transition: border-color .18s ease, transform .18s ease;
}
.card:hover { border-color: var(--accent); transform: translateY(-2px); }
.card__tag {
  display: inline-block;
  font-family: var(--mono); font-size: .72rem; letter-spacing: .04em;
  text-transform: uppercase; color: var(--accent);
  background: var(--accent-bg); padding: .25rem .6rem;
  border-radius: 3px; margin: 0 0 .9rem;
}
.card__title { font-size: 1.3rem; margin-bottom: .5rem; }
.card__meta {
  font-family: var(--mono); font-size: .72rem; color: var(--ink-soft);
  margin: 0 0 1rem;
}
.card--ghost { border-style: dashed; background: transparent; }
.card--ghost:hover { transform: none; border-color: var(--ink-soft); }
.card__body { margin: 0 0 1rem; }
.card__body dt {
  font-family: var(--mono); font-size: .7rem; letter-spacing: .05em;
  text-transform: uppercase; color: var(--ink-soft);
  margin-top: .8rem;
}
.card__body dd { margin: .15rem 0 0; color: var(--ink); font-size: .95rem; }
.card__links { font-family: var(--mono); font-size: .82rem; margin: 0; }
.card__links span { color: var(--line); margin: 0 .5rem; }

/* ---------- Résumé / CV ---------- */
.cv { display: grid; grid-template-columns: 1fr; gap: 2.5rem; }
.cv__heading {
  font-family: var(--mono); font-size: .78rem; letter-spacing: .05em;
  text-transform: uppercase; color: var(--accent); font-weight: 500;
  margin: 0 0 1rem;
}
.cv__list { list-style: none; margin: 0; padding: 0; }
.cv__list li { margin-bottom: 1.1rem; }
.cv__list--compact li { margin-bottom: .5rem; display: flex; gap: .75rem; align-items: baseline; }
.cv__date {
  display: block; font-family: var(--mono); font-size: .72rem;
  color: var(--ink-soft); margin-bottom: .15rem;
}
.cv__primary { display: block; font-weight: 600; }
.cv__list--compact .cv__primary { width: 5.5rem; flex-shrink: 0; }
.cv__secondary { display: block; font-size: .9rem; color: var(--ink-soft); }
.cv__certs { font-size: .9rem; color: var(--ink-soft); margin-top: 1.25rem; }
.cv__subhead {
  font-family: var(--mono); font-size: .72rem; letter-spacing: .04em;
  text-transform: uppercase; color: var(--ink-soft);
  margin: 1.75rem 0 .75rem;
}
.cv__subhead:first-of-type { margin-top: 0; }

.tag-list {
  list-style: none; margin: 0 0 .25rem; padding: 0;
  display: flex; flex-wrap: wrap; gap: .5rem;
}
.tag-list li {
  font-size: .85rem; padding: .3rem .75rem;
  border: 1px solid var(--line); border-radius: 20px; color: var(--ink-soft);
}

/* ---------- Contact ---------- */
.contact-list { list-style: none; margin: 0; padding: 0; }
.contact-list li {
  display: flex; flex-direction: column; gap: .15rem;
  padding: 1rem 0; border-top: 1px solid var(--line);
}
.contact-list li:first-child { border-top: none; }
.contact-list__label {
  font-family: var(--mono); font-size: .72rem; letter-spacing: .05em;
  text-transform: uppercase; color: var(--ink-soft);
}

/* ---------- Footer ---------- */
.site-footer {
  border-top: 1px solid var(--line);
  padding: 2rem var(--pad);
  text-align: center;
}
.site-footer p {
  margin: 0; font-family: var(--mono); font-size: .78rem; color: var(--ink-soft);
}

/* ===========================================================
   Responsive — tablet & up
   =========================================================== */
@media (min-width: 640px) {
  .contact-list li { flex-direction: row; align-items: baseline; gap: 1.5rem; }
  .contact-list__label { width: 7rem; flex-shrink: 0; }
}
@media (min-width: 768px) {
  .nav__burger { display: none; }
  .nav__links {
    display: flex; flex-direction: row; width: auto;
    margin-top: 0; gap: 1.75rem;
  }
  .nav__links a { padding: 0; }
  .projects { grid-template-columns: repeat(2, 1fr); gap: 1.5rem; }
  .cv {
    display: grid;                        /* ← add this line */
    grid-template-columns: repeat(3, 1fr);
    column-gap: 2.5rem;
    row-gap: 3.5rem;
  }
  .cv__block--wide { grid-column: 1 / span 2; }
  .hero, .section { padding-top: 5rem; padding-bottom: 5rem; }
}

/* ===========================================================
   Reduced motion
   =========================================================== */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; }
}