/* ---------- Tokens ---------- */
:root {
  --bg: #f4f6f2;
  --bg-top: #e3edf9;
  --surface: #ffffff;
  --ink: #16202a;
  --muted: #5a6670;
  --line: #dfe4de;
  --accent: #1b5bb0;       /* Djurdjura sky / locomotive blue */
  --accent-soft: #e6effb;
  --green: #3a7a2a;        /* El Esnam fields */
  --green-soft: #e7f2e1;
  --ridge: #d7e2ef;
  --s1: #2a78d6; --s2: #eb6834; --s3: #1baf7a;
  --shadow: 0 1px 2px rgba(20, 30, 40, .06), 0 6px 24px rgba(20, 30, 40, .07);
  --radius: 14px;
  --serif: "Source Serif 4", Georgia, serif;
  --sans: "Inter", system-ui, -apple-system, "Segoe UI", sans-serif;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0e1318; --bg-top: #122033; --surface: #151c23; --ink: #e6ebef; --muted: #98a4ae;
    --line: #25303a; --accent: #74aaff; --accent-soft: #17273d; --green: #8cc972; --green-soft: #1a2a17;
    --ridge: #1a2634; --s1: #3987e5; --s2: #d95926; --s3: #199e70; --shadow: 0 1px 2px rgba(0,0,0,.3), 0 6px 24px rgba(0,0,0,.25);
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #0e1318; --bg-top: #122033; --surface: #151c23; --ink: #e6ebef; --muted: #98a4ae;
  --line: #25303a; --accent: #74aaff; --accent-soft: #17273d; --green: #8cc972; --green-soft: #1a2a17;
  --ridge: #1a2634; --s1: #3987e5; --s2: #d95926; --s3: #199e70; --shadow: 0 1px 2px rgba(0,0,0,.3), 0 6px 24px rgba(0,0,0,.25);
  color-scheme: dark;
}

/* ---------- Base ---------- */
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--ink);
  background: linear-gradient(180deg, var(--bg-top) 0, var(--bg) 520px) no-repeat, var(--bg);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
h1, h2, h3 { font-family: var(--serif); font-weight: 600; line-height: 1.25; margin: 0; }
.wrap { width: 100%; max-width: 1040px; margin: 0 auto; padding: 0 16px; }
main { flex: 1; }

/* ---------- Nav ---------- */
.nav {
  position: sticky; top: 0; z-index: 20;
  background: color-mix(in srgb, var(--surface) 82%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.nav .wrap { display: flex; align-items: center; gap: 16px; height: 60px; }
.brand { font-family: var(--serif); font-weight: 600; font-size: 1.15rem; color: var(--ink); white-space: nowrap; }
.brand:hover { text-decoration: none; }
.tabs { display: flex; gap: 2px; margin-left: auto; overflow-x: auto; scrollbar-width: none; }
.tabs::-webkit-scrollbar { display: none; }
.tabs a {
  color: var(--muted); font-size: .92rem; font-weight: 500;
  padding: 7px 12px; border-radius: 999px; white-space: nowrap;
}
.tabs a:hover { color: var(--ink); background: var(--accent-soft); text-decoration: none; }
.tabs a[aria-current="page"] { color: var(--accent); background: var(--accent-soft); }
.theme-btn {
  border: 1px solid var(--line); background: var(--surface); color: var(--muted);
  width: 34px; height: 34px; border-radius: 50%; cursor: pointer; flex: none; font-size: 15px;
}

/* ---------- Views ---------- */
.view { display: none; padding: 28px 0 56px; animation: fade .35s ease; }
.view.active { display: block; }
@keyframes fade { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: none; } }
.page-head { margin: 12px 0 28px; }
.page-head h1 { font-size: clamp(1.8rem, 4vw, 2.4rem); }
.page-head p { color: var(--muted); margin: 6px 0 0; max-width: 680px; }
.section-title {
  font-size: 1.35rem; margin: 44px 0 16px; padding-bottom: 8px; border-bottom: 1px solid var(--line);
}
.card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow); }

/* ---------- Hero (About) ---------- */
.hero { position: relative; }
.cover {
  position: relative; height: clamp(200px, 36vw, 360px);
  border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow);
}
.cover img { width: 100%; height: 100%; object-fit: cover; object-position: center 45%; display: block; }
.cover figcaption {
  position: absolute; right: 12px; bottom: 10px;
  font-size: .78rem; color: #fff; background: rgba(10, 20, 30, .45);
  padding: 4px 10px; border-radius: 999px; backdrop-filter: blur(4px);
}
.profile {
  display: grid; grid-template-columns: 250px 1fr; gap: 28px; align-items: end;
  margin-top: -110px; padding: 0 24px; position: relative;
}
.portrait {
  width: 250px; aspect-ratio: 640 / 862; object-fit: cover; display: block;
  border-radius: var(--radius); border: 5px solid var(--surface); box-shadow: var(--shadow);
  background: var(--surface);
}
.identity { padding-bottom: 6px; }
.identity h1 { font-size: clamp(2rem, 5vw, 2.8rem); }
.headline { font-size: 1.05rem; margin: 6px 0 2px; }
.location { color: var(--muted); font-size: .93rem; margin: 0 0 14px; }
.links { display: flex; flex-wrap: wrap; gap: 8px; }
.btn {
  display: inline-flex; align-items: center; gap: 7px;
  font-size: .88rem; font-weight: 500; padding: 7px 14px; border-radius: 999px;
  border: 1px solid var(--line); background: var(--surface); color: var(--ink);
}
.btn:hover { border-color: var(--accent); color: var(--accent); text-decoration: none; }
.btn.primary { background: var(--accent); border-color: var(--accent); color: #fff; }
.btn.primary:hover { color: #fff; filter: brightness(1.08); }
.btn svg { width: 16px; height: 16px; fill: currentColor; flex: none; }
.btn.soon { color: var(--muted); border-style: dashed; cursor: default; }
.btn.soon:hover { border-color: var(--line); color: var(--muted); }

.about-grid { display: grid; grid-template-columns: 1fr 300px; gap: 36px; margin-top: 40px; }
.bio p { margin: 0 0 14px; }
.chips { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 8px; }
.chip {
  font-size: .84rem; padding: 5px 12px; border-radius: 999px;
  background: var(--accent-soft); color: var(--accent); font-weight: 500;
}
.chip.green { background: var(--green-soft); color: var(--green); }
.label { font-size: .78rem; letter-spacing: .08em; text-transform: uppercase; color: var(--muted); font-weight: 600; margin: 26px 0 8px; }

/* Line portrait */
.sketch-card { padding: 16px 16px 12px; align-self: start; }
.sketch-card svg { width: 80%; height: auto; display: block; margin: 12px auto 4px; }
.sketch-card path {
  fill: none; stroke: var(--ink); stroke-width: 1.3; stroke-linecap: round; stroke-linejoin: round;
  stroke-dasharray: 1; stroke-dashoffset: 1;
}
.sketch-card.drawing path { animation: draw var(--dur, 1.2s) cubic-bezier(.45, .05, .35, 1) forwards; animation-delay: var(--delay, 0s); }
.sketch-card.done path { stroke-dashoffset: 0; }
@keyframes draw { to { stroke-dashoffset: 0; } }
.sketch-foot { display: flex; justify-content: space-between; align-items: center; margin-top: 6px; }
.sketch-foot span { font-size: .8rem; color: var(--muted); font-family: var(--serif); font-style: italic; }
.replay { white-space: nowrap; border: none; background: none; color: var(--accent); font-size: .82rem; cursor: pointer; padding: 4px 0; }
@media (prefers-reduced-motion: reduce) {
  .sketch-card path { stroke-dashoffset: 0; animation: none !important; }
  .view { animation: none; }
}

/* News */
.news { list-style: none; padding: 0; margin: 0; }
.news li { display: grid; grid-template-columns: 96px 1fr; gap: 16px; padding: 12px 0; border-bottom: 1px dashed var(--line); }
.news li:last-child { border-bottom: none; }
.news time { font-size: .85rem; font-weight: 600; color: var(--green); padding-top: 1px; }

/* ---------- Publications ---------- */
.pub { padding: 22px 24px; margin-bottom: 16px; display: grid; grid-template-columns: 110px 1fr; gap: 20px; }
.pub-tag {
  font-family: var(--serif); font-weight: 700; font-size: 1.15rem; color: var(--accent);
  background: var(--accent-soft); border-radius: 10px; height: 74px;
  display: flex; align-items: center; justify-content: center; text-align: center; padding: 6px;
}
.pub.related .pub-tag { color: var(--green); background: var(--green-soft); }
.pub h3 { font-size: 1.15rem; margin-bottom: 6px; }
.authors { font-size: .93rem; color: var(--muted); margin: 0; }
.authors b { color: var(--ink); font-weight: 600; }
.venue { font-size: .9rem; margin: 4px 0 10px; }
.venue em { color: var(--muted); }
.venue strong { color: var(--green); font-weight: 600; }
.pub .summary { font-size: .95rem; margin: 0 0 12px; }
.pub .links .btn { padding: 5px 12px; font-size: .83rem; }
.why { font-size: .9rem; margin: 0 0 12px; padding: 8px 12px; border-left: 3px solid var(--green); background: var(--green-soft); border-radius: 0 8px 8px 0; }

/* ---------- Publication animations ---------- */
.viz { margin: 4px 0 16px; border: 1px solid var(--line); border-radius: 12px; background: var(--bg); padding: 12px 14px 10px; }
.viz-head { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-bottom: 4px; }
.viz-title { font-family: var(--serif); font-weight: 600; font-size: 1.05rem; }
.viz-btn {
  flex: none; border: 1px solid var(--line); background: var(--surface); color: var(--ink);
  font: 500 .8rem var(--sans); padding: 4px 11px; border-radius: 999px; cursor: pointer;
}
.viz-btn:hover { border-color: var(--accent); color: var(--accent); }
.viz-stage canvas { display: block; width: 100%; }
.viz figcaption { display: flex; flex-wrap: wrap; justify-content: space-between; align-items: baseline; gap: 4px 12px; margin-top: 6px; }
.viz-caption { font-size: .92rem; min-height: 1.6em; }
.viz-caption.final { font-family: var(--serif); font-weight: 600; font-size: 1rem; }
.viz-note { font-size: .74rem; color: var(--muted); }

.plasma { padding: 14px; margin-bottom: 16px; display: grid; grid-template-columns: 260px 1fr; gap: 20px; align-items: center; }
.plasma h3 { font-size: 1.1rem; }
.plasma p { margin: 4px 0 6px; font-size: .95rem; }
.plasma-media { position: relative; }
.plasma-canvas { display: block; width: 100%; aspect-ratio: 2 / 1; border-radius: 10px; background: var(--line); }
.plasma-btn {
  position: absolute; right: 8px; bottom: 8px; width: 28px; height: 28px; border-radius: 50%;
  border: none; background: rgba(15, 20, 25, .5); color: #fff; font-size: 11px; cursor: pointer;
}

/* ---------- Courses ---------- */
.courses { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.course { padding: 22px; display: flex; flex-direction: column; }
.course .num { font-family: var(--serif); font-size: 2rem; color: var(--accent); line-height: 1; margin-bottom: 12px; }
.course h3 { font-size: 1.2rem; margin-bottom: 8px; }
.course p { font-size: .93rem; color: var(--muted); margin: 0 0 14px; }
.course ul { font-size: .9rem; margin: 0 0 18px; padding-left: 18px; }
.course .links { margin-top: auto; }

/* ---------- CV ---------- */
.cv-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-bottom: 8px; }
.timeline { list-style: none; margin: 0; padding: 0; }
.timeline > li { display: grid; grid-template-columns: 150px 1fr; gap: 20px; padding: 14px 0; border-bottom: 1px solid var(--line); }
.timeline > li:last-child { border-bottom: none; }
.when { font-size: .88rem; color: var(--muted); font-weight: 500; }
.what h3 { font-family: var(--sans); font-size: 1rem; font-weight: 600; }
.what .org { color: var(--muted); font-size: .92rem; margin: 2px 0 6px; }
.what ul { margin: 6px 0 0; padding-left: 18px; font-size: .93rem; }
.what li { margin-bottom: 4px; }
.skills { display: grid; grid-template-columns: 150px 1fr; gap: 10px 20px; font-size: .94rem; }
.skills dt { font-weight: 600; }
.skills dd { margin: 0; color: var(--muted); }
.cv-embed { margin-top: 18px; height: 80vh; overflow: hidden; }
.cv-embed iframe { width: 100%; height: 100%; border: 0; }

/* ---------- Footer ---------- */
footer { margin-top: 40px; color: var(--muted); font-size: .88rem; }
.ridge { display: block; width: 100%; height: 70px; }
.ridge polygon { fill: var(--ridge); }
.foot { background: var(--ridge); padding: 6px 0 22px; }
.foot .wrap { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 10px; }
.foot a { color: var(--muted); }

/* ---------- Responsive ---------- */
@media (max-width: 860px) {
  .about-grid { grid-template-columns: 1fr; }
  .sketch-card { max-width: 320px; }
  .courses { grid-template-columns: 1fr; }
}
@media (max-width: 680px) {
  .nav .wrap { height: auto; padding-top: 10px; padding-bottom: 8px; flex-wrap: wrap; gap: 6px; }
  .tabs { margin-left: 0; width: 100%; order: 3; }
  .tabs a { padding: 6px 9px; font-size: .86rem; }
  .cover { height: 230px; }
  .cover figcaption { top: 10px; bottom: auto; left: 10px; right: auto; font-size: .72rem; max-width: calc(100% - 20px); }
  .theme-btn { margin-left: auto; }
  .profile { grid-template-columns: 1fr; margin-top: -70px; padding: 0 12px; gap: 16px; }
  .portrait { width: 170px; }
  .pub { grid-template-columns: 1fr; padding: 18px; gap: 12px; }
  .pub-tag { height: auto; width: fit-content; padding: 6px 14px; font-size: 1rem; }
  .viz { padding: 10px 10px 8px; }
  .plasma { grid-template-columns: 1fr; gap: 12px; }
  .plasma-canvas { aspect-ratio: 3 / 1; }
  .news li, .timeline > li, .skills { grid-template-columns: 1fr; gap: 4px; }
}