/* Layout: one centred column (max 1080px); sections separated by hairlines; mono eyebrows label each section.
   Researcher + security engineer: ink navy, cool greys, one deep teal accent. */
:root {
  --bg: #f6f8fa;
  --surface: #ffffff;
  --ink: #0f1b2d;
  --muted: #536175;
  --line: #dbe2ea;
  --accent: #0b5f6b;
  --accent-soft: #e2f0f1;
  --on-accent: #ffffff;
  --display: "Fraunces", Georgia, "Times New Roman", serif;
  --sans: "IBM Plex Sans", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --radius: 10px;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0b121c; --surface: #111b28; --ink: #e5ecf4; --muted: #95a3b6; --line: #1f2c3c;
    --accent: #5cc4cf; --accent-soft: #12303a; --on-accent: #06222a; color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #0b121c; --surface: #111b28; --ink: #e5ecf4; --muted: #95a3b6; --line: #1f2c3c;
  --accent: #5cc4cf; --accent-soft: #12303a; --on-accent: #06222a; color-scheme: dark;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 76px; -webkit-text-size-adjust: 100%; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } * { transition: none !important; } }
body { margin: 0; background: var(--bg); color: var(--ink); font: 17px/1.65 var(--sans); }
img { max-width: 100%; height: auto; display: block; }
a { color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { text-decoration-thickness: 2px; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 4px; }
h1, h2, h3 { margin: 0; text-wrap: balance; line-height: 1.2; }
h2 { font: 600 clamp(28px, 4vw, 38px)/1.15 var(--display); letter-spacing: -.01em; }
h3 { font-size: 19px; font-weight: 600; }
p { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }

.wrap { width: 100%; max-width: 1080px; margin: 0 auto;
  padding-left: max(20px, env(safe-area-inset-left, 0px)); padding-right: max(20px, env(safe-area-inset-right, 0px)); }
.skip { position: absolute; left: -999px; top: 8px; background: var(--accent); color: var(--on-accent); padding: 8px 14px; border-radius: 6px; z-index: 100; }
.skip:focus { left: 12px; }

.eyebrow, .label { font: 500 12.5px/1.4 var(--mono); letter-spacing: .1em; text-transform: uppercase; color: var(--accent); }
.eyebrow a { text-decoration: none; }
.meta { color: var(--muted); font-size: 15px; }
.muted { color: var(--muted); }

/* Header */
.site-header { position: sticky; top: 0; z-index: 50; background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: saturate(1.4) blur(10px); -webkit-backdrop-filter: saturate(1.4) blur(10px); border-bottom: 1px solid var(--line); }
.header-inner { display: flex; align-items: center; gap: 24px; height: 60px; }
.brand { font: 600 19px/1 var(--display); color: var(--ink); text-decoration: none; white-space: nowrap; }
.brand span { color: var(--accent); }
.nav { display: flex; gap: 22px; margin-left: auto; overflow-x: auto; scrollbar-width: none; }
.nav::-webkit-scrollbar { display: none; }
.nav a { color: var(--muted); text-decoration: none; font-size: 15px; white-space: nowrap; padding: 6px 0; }
.nav a:hover { color: var(--ink); }
.theme-toggle { flex: none; display: grid; place-items: center; width: 36px; height: 36px; border: 1px solid var(--line);
  border-radius: 8px; background: var(--surface); color: var(--ink); cursor: pointer; }
.theme-toggle .i-sun { display: none; }
:root[data-theme="dark"] .theme-toggle .i-sun { display: block; }
:root[data-theme="dark"] .theme-toggle .i-moon { display: none; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .theme-toggle .i-sun { display: block; }
  :root:not([data-theme="light"]) .theme-toggle .i-moon { display: none; }
}

/* Hero */
.hero { padding-block: clamp(48px, 8vw, 88px) 40px; }
.hero-text { display: grid; gap: 18px; min-width: 0; }
.hero h1 { font: 600 clamp(42px, 7vw, 68px)/1.02 var(--display); letter-spacing: -.02em; }
.headline { font-size: clamp(19px, 2.2vw, 23px); line-height: 1.45; font-weight: 500; max-width: 34em; }
.intro { color: var(--muted); max-width: 40em; }

.btn-row { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 6px; }
.btn { display: inline-flex; align-items: center; min-height: 44px; padding: 0 18px; border: 1px solid var(--line); border-radius: 8px;
  background: var(--surface); color: var(--ink); font: 500 15px/1 var(--sans); text-decoration: none; cursor: pointer; }
.btn:hover { border-color: var(--accent); }
.btn-primary { background: var(--accent); border-color: var(--accent); color: var(--on-accent); }
.btn-primary:hover { filter: brightness(1.08); }

.highlights { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); margin-top: 48px;
  border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface); }
.highlights li { display: grid; gap: 2px; padding: 18px 20px; border-left: 1px solid var(--line); }
.highlights li:first-child { border-left: 0; }
.highlights strong { font: 600 22px/1.2 var(--display); font-variant-numeric: tabular-nums; }
.highlights span { color: var(--muted); font-size: 14px; }

/* Sections */
.section { padding-block: clamp(56px, 8vw, 88px); border-top: 1px solid var(--line); }
.section .wrap { display: grid; gap: 20px; }
.section-lede { color: var(--muted); max-width: 44em; }
.sub { margin-top: 28px; font: 600 22px/1.3 var(--display); }
.more { margin-top: 4px; }
.two-col { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 2fr); gap: 20px 48px; align-items: start; }
.section .two-col { gap: 20px 48px; }
.prose { display: grid; gap: 16px; max-width: 66ch; min-width: 0; }
.prose h2 { font-size: 26px; margin-top: 12px; }
.prose ul { list-style: disc; padding-left: 1.2em; display: grid; gap: 6px; }
.prose pre { overflow-x: auto; background: var(--surface); border: 1px solid var(--line); padding: 14px; border-radius: 8px; font: 14px/1.5 var(--mono); }
.prose code { font-family: var(--mono); font-size: .9em; }

.card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; display: grid; gap: 12px; align-content: start; min-width: 0; }
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 20px; }
.grid-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 32px; }

.tags { display: flex; flex-wrap: wrap; gap: 6px; }
.tags li { font: 13px/1 var(--mono); padding: 6px 9px; border-radius: 6px; background: var(--accent-soft); color: var(--ink); }

/* Focus */
.focus-list { display: grid; border-top: 1px solid var(--line); }
.focus-list li { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1.6fr); gap: 8px 32px; padding: 18px 0; border-bottom: 1px solid var(--line); }
.focus-head { display: grid; gap: 4px; align-content: start; }
.level { font: 12.5px/1.4 var(--mono); color: var(--muted); letter-spacing: .04em; }
.focus-list p { color: var(--ink); }

/* Research */
.thesis { padding: 28px; gap: 14px; }
.thesis h3 { font: 600 clamp(20px, 2.6vw, 25px)/1.3 var(--display); }
.results { display: flex; flex-wrap: wrap; gap: 12px 40px; margin: 6px 0 0; }
.results div { display: grid; gap: 2px; }
.results dt { font-size: 13.5px; color: var(--muted); order: 2; }
.results dd { margin: 0; font: 600 30px/1.1 var(--display); color: var(--accent); font-variant-numeric: tabular-nums; order: 1; }
.pubs { display: grid; gap: 0; border-top: 1px solid var(--line); counter-reset: pub; }
.pubs li { display: grid; gap: 6px; padding: 18px 0; border-bottom: 1px solid var(--line); }
.pub-title { font-weight: 600; font-size: 17.5px; line-height: 1.45; }
.pub-foot { display: flex; flex-wrap: wrap; gap: 8px 16px; align-items: center; font: 14px/1.4 var(--mono); overflow-wrap: anywhere; }
.role { padding: 4px 8px; border-radius: 6px; border: 1px solid var(--line); color: var(--muted); font-size: 12.5px; }
.role-first { border-color: var(--accent); color: var(--accent); }
.interests { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 32px; }
.interests ul { display: grid; gap: 14px; margin-top: 12px; }
.interests li { display: grid; gap: 2px; }
.interests span { color: var(--muted); font-size: 15px; }

/* Projects */
.card-top { display: flex; }
.status { font: 500 12px/1 var(--mono); letter-spacing: .06em; text-transform: uppercase; padding: 6px 9px; border-radius: 999px; }
.status-wip { background: #fff3d6; color: #7a5300; }
.status-done { background: #dcf3e4; color: #1d6b3a; }
:root[data-theme="dark"] .status-wip { background: #3a2e10; color: #f2cf7a; }
:root[data-theme="dark"] .status-done { background: #143322; color: #8fdcab; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .status-wip { background: #3a2e10; color: #f2cf7a; }
  :root:not([data-theme="light"]) .status-done { background: #143322; color: #8fdcab; }
}
.project-card h3 a { color: var(--ink); text-decoration: none; }
.project-card h3 a:hover { color: var(--accent); }
.project-card p { color: var(--muted); }
.card-links { display: flex; flex-wrap: wrap; gap: 6px 16px; font-size: 15px; margin-top: 4px; }

/* Timeline */
.timeline { display: grid; border-top: 1px solid var(--line); }
.timeline > li { display: grid; grid-template-columns: 190px minmax(0, 1fr); gap: 8px 32px; padding: 22px 0; border-bottom: 1px solid var(--line); }
.timeline > li > div { display: grid; gap: 6px; }
.dates { font: 14px/1.6 var(--mono); color: var(--muted); font-variant-numeric: tabular-nums; }
.timeline ul { list-style: disc; padding-left: 1.2em; display: grid; gap: 4px; margin-top: 4px; }

/* Skills & certs */
.skill-group { display: grid; gap: 10px; align-content: start; }
.group-title { font-size: 17px; margin-bottom: 12px; }
.certs { display: grid; gap: 14px; }
.cert-name { font-weight: 500; }

/* Notes */
.post-list { display: grid; border-top: 1px solid var(--line); }
.post-list li { display: flex; justify-content: space-between; gap: 16px; padding: 14px 0; border-bottom: 1px solid var(--line); }
.post-list time { color: var(--muted); font: 14px/1.6 var(--mono); white-space: nowrap; }
.empty { color: var(--muted); padding: 24px 0; }

/* Contact */
.contact-list { display: grid; gap: 10px; margin-top: 20px; }
.contact-list li { display: grid; grid-template-columns: 96px minmax(0, 1fr); align-items: baseline; overflow-wrap: anywhere; }
.contact-list .label { color: var(--muted); }
.contact-form { display: grid; gap: 8px; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; }
.contact-form label { font-size: 14px; font-weight: 500; margin-top: 6px; }
.contact-form input, .contact-form textarea { width: 100%; font: 16px/1.5 var(--sans); color: var(--ink); background: var(--bg);
  border: 1px solid var(--line); border-radius: 8px; padding: 10px 12px; }
.contact-form input:focus, .contact-form textarea:focus { outline: 2px solid var(--accent); outline-offset: 0; border-color: transparent; }
.contact-form button { margin-top: 12px; justify-self: start; }
.form-status { font-size: 14px; color: var(--muted); min-height: 1.4em; }
.form-status.is-ok { color: var(--accent); font-weight: 500; }
.form-status.is-error { color: #b42318; }
:root[data-theme="dark"] .form-status.is-error { color: #ff8a80; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .form-status.is-error { color: #ff8a80; } }
.contact-form .hp { display: none; }
.contact-form button[disabled] { opacity: .6; cursor: progress; }

/* Inner pages */
.page { padding-block: 48px 88px; display: grid; gap: 28px; }
.page-head { display: grid; gap: 14px; justify-items: start; }
.page-head h1 { font: 600 clamp(32px, 5vw, 48px)/1.1 var(--display); letter-spacing: -.01em; }
.lede { font-size: 19px; color: var(--muted); max-width: 40em; }
.embed iframe { width: 100%; height: min(80vh, 720px); border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface); }
.embed.video iframe { height: auto; aspect-ratio: 16 / 9; max-width: 100%; }

.site-footer { border-top: 1px solid var(--line); padding-block: 28px; color: var(--muted); font-size: 14px; }
.footer-inner { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 12px; }
.footer-links { display: flex; flex-wrap: wrap; gap: 16px; }
.footer-links a { color: var(--muted); }

/* Narrow screens */
@media (max-width: 860px) {
  .grid-3 { grid-template-columns: 1fr; }
  .two-col, .interests { grid-template-columns: 1fr; }
  .highlights { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .highlights li:nth-child(3) { border-left: 0; }
  .highlights li:nth-child(n+3) { border-top: 1px solid var(--line); }
}
@media (max-width: 640px) {
  body { font-size: 16px; }
  .header-inner { height: auto; flex-wrap: wrap; gap: 4px 12px; padding-block: 10px 0; }
  .nav { order: 3; width: 100%; margin: 0; gap: 18px; padding-bottom: 6px; }
  .theme-toggle { margin-left: auto; }
  html { scroll-padding-top: 100px; }
  .focus-list li, .timeline > li { grid-template-columns: 1fr; }
  .grid { grid-template-columns: 1fr; }
  .post-list li { flex-direction: column; gap: 2px; }
}