/* Matthew Davidson, engineering portfolio
   Warm stone drafting paper with a faint navy drawing grid, navy ink and one teal
   accent; the current-work band is a navy blueprint sheet.
   Space Grotesk for text, JetBrains Mono for labels, dates and the title block. */

:root {
  --paper: #f1efea;
  --deep: #e6e3dc;
  --surface: #fbfaf7;
  --ink: #14202e;
  --graphite: #585a5c;
  --rule: rgb(20 32 46 / 0.14);
  --strong-rule: rgb(20 32 46 / 0.5);
  --accent: #0a6b80;
  --on-accent: #ffffff;

  /* Drawing grid: minor lines every 24px, major lines every 120px. */
  --grid-minor: rgb(14 26 43 / 0.035);
  --grid-major: rgb(14 26 43 / 0.06);

  --sans: "Space Grotesk", system-ui, sans-serif;
  --mono: "JetBrains Mono", ui-monospace, "SF Mono", Menlo, monospace;
  --measure: 66ch;
  --gutter: clamp(16px, 4vw, 48px);
  --max: 1200px;
  --radius: 2px;
  color-scheme: light;
}

/* Declared wherever the grid colours change, so --grid picks up the local values. */
:root, .feature {
  --grid:
    linear-gradient(var(--grid-major) 1px, transparent 1px) 0 0 / 120px 120px,
    linear-gradient(90deg, var(--grid-major) 1px, transparent 1px) 0 0 / 120px 120px,
    linear-gradient(var(--grid-minor) 1px, transparent 1px) 0 0 / 24px 24px,
    linear-gradient(90deg, var(--grid-minor) 1px, transparent 1px) 0 0 / 24px 24px;
}

*, *::before, *::after { box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: 72px; background: var(--paper); }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

body {
  margin: 0;
  background: var(--grid), var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 1.0625rem;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

::selection { background: var(--accent); color: var(--on-accent); }

img, video, svg { display: block; max-width: 100%; }
img, video { height: auto; }
code { font-family: var(--mono); font-size: 0.85em; }

a { color: var(--accent); text-underline-offset: 0.2em; text-decoration-thickness: 1px; }
a:hover { text-decoration-thickness: 2px; }

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

h1, h2, h3 { margin: 0; font-weight: 500; line-height: 1.1; text-wrap: balance; }
h1 { font-size: clamp(2.6rem, 6.4vw, 5.2rem); letter-spacing: -0.035em; }
h2 { font-size: clamp(1.9rem, 3.6vw, 2.9rem); letter-spacing: -0.025em; }
h3 { font-size: 1.2rem; line-height: 1.25; letter-spacing: -0.005em; }
p { margin: 0 0 1em; }
ul { margin: 0; padding-left: 1.1em; }
li + li { margin-top: 0.35em; }
li::marker { color: var(--accent); }

/* Small labels set in the mono face, like the lettering on a drawing. */
.meta, .kicker {
  font-family: var(--mono);
  font-size: 0.75rem;
  font-weight: 400;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.wrap { max-width: var(--max); margin-inline: auto; padding-inline: var(--gutter); }
.section { padding-block: clamp(64px, 10vw, 128px); }
.section-head { max-width: var(--measure); margin-bottom: clamp(32px, 5vw, 56px); }
.section-head p { color: var(--graphite); margin-top: 1rem; margin-bottom: 0; }
.muted { color: var(--graphite); }
.skip { position: absolute; left: -999px; }
.skip:focus { left: 16px; top: 16px; z-index: 100; background: var(--surface); padding: 8px 12px; }

/* ---------- Top bar ---------- */

.topbar {
  position: sticky; top: 0; z-index: 20;
  background: color-mix(in srgb, var(--paper) 86%, transparent);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--rule);
}
.topbar .wrap { display: flex; align-items: center; justify-content: space-between; gap: 16px; height: 60px; }
.brand {
  display: inline-flex; align-items: center; gap: 10px;
  color: var(--ink); text-decoration: none;
  font-family: var(--mono); font-size: 0.85rem; font-weight: 500;
  letter-spacing: 0.1em; text-transform: uppercase; white-space: nowrap;
}
/* A small registration mark in the accent colour. */
.brand::before { content: ""; width: 10px; height: 10px; border: 1.5px solid var(--accent); flex: none; }
/* On narrow phones the name and the four links do not fit in one row, so the brand
   becomes the MD monogram used for the favicon; the link keeps the full name as its label. */
.brand-short { display: none; }
@media (max-width: 480px) {
  .brand-full { display: none; }
  .brand-short { display: inline; }
}
.topbar nav ul { display: flex; gap: clamp(14px, 2.5vw, 32px); list-style: none; padding: 0; margin: 0; }
.topbar nav li + li { margin: 0; }
.topbar nav a { color: var(--ink); text-decoration: none; font-size: 0.95rem; }
.topbar nav a:hover { color: var(--accent); }
@media (max-width: 640px) {
  .topbar nav a { font-size: 0.9rem; }
}

/* ---------- Hero ---------- */

.hero {
  position: relative; overflow: hidden;
  background: var(--grid), var(--paper);
  border-bottom: 1px solid var(--rule);
}
.hero .wrap {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  grid-template-areas: "text block" "links block";
  column-gap: clamp(24px, 5vw, 72px);
  row-gap: 40px;
  padding-block: clamp(56px, 9vw, 120px) clamp(40px, 6vw, 72px);
}
.hero-text { grid-area: text; align-self: center; }
.hero h1 small {
  display: block; margin-top: 1.1em;
  font-family: var(--mono); font-size: max(0.8rem, 0.2em); font-weight: 400;
  letter-spacing: 0.12em; text-transform: uppercase; color: var(--accent);
}
.hero .lead { font-size: clamp(1.1rem, 1.6vw, 1.3rem); line-height: 1.55; max-width: 34em; margin: 1.6rem 0 0; }
.hero-links { grid-area: links; align-self: start; display: flex; flex-wrap: wrap; gap: 12px 28px; }

.button {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 11px 20px;
  border: 1px solid var(--strong-rule);
  border-radius: var(--radius);
  color: var(--ink);
  text-decoration: none;
  font-family: var(--mono);
  font-size: 0.8rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  background: transparent;
  cursor: pointer;
  transition: background-color 0.15s, color 0.15s, border-color 0.15s;
}
.button:hover { border-color: var(--accent); color: var(--accent); }
.button.primary { background: var(--accent); border-color: var(--accent); color: var(--on-accent); }
.button.primary:hover { background: var(--ink); border-color: var(--ink); color: var(--on-accent); }
.textlink { align-self: center; color: var(--ink); font-size: 0.95rem; }
.textlink:hover { color: var(--accent); }

/* Title block, as on a drawing sheet */
.titleblock {
  grid-area: block;
  align-self: end;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border: 1.5px solid var(--accent);
  background: color-mix(in srgb, var(--paper) 80%, transparent);
  margin: 0;
  font-size: 0.92rem;
}
.titleblock div { padding: 8px 12px 9px; border-right: 1px solid var(--rule); border-bottom: 1px solid var(--rule); }
.titleblock div:nth-child(2n) { border-right: 0; }
.titleblock div:nth-last-child(-n + 2) { border-bottom: 0; }
.titleblock dt {
  color: var(--accent); line-height: 1.5;
  font-family: var(--mono); font-size: 0.68rem; letter-spacing: 0.1em; text-transform: uppercase;
}
.titleblock dd { margin: 0; line-height: 1.35; }

@media (max-width: 860px) {
  .hero .wrap { grid-template-columns: 1fr; grid-template-areas: "text" "links" "block"; row-gap: 32px; }
}

/* ---------- Capabilities ---------- */

.capabilities { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 0; border-top: 1.5px solid var(--accent); }
.capabilities > div { padding: 24px 24px 8px 0; }
.capabilities > div + div { padding-left: 24px; border-left: 1px solid var(--rule); }
.capabilities h3 { margin-bottom: 0.6rem; }
.capabilities p { color: var(--graphite); font-size: 0.97rem; }
@media (max-width: 960px) {
  .capabilities { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .capabilities > div:nth-child(3) { padding-left: 0; border-left: 0; }
  .capabilities > div:nth-child(n + 3) { border-top: 1px solid var(--rule); }
}
@media (max-width: 560px) {
  .capabilities { grid-template-columns: 1fr; }
  .capabilities > div, .capabilities > div + div { padding-left: 0; border-left: 0; }
  .capabilities > div + div { border-top: 1px solid var(--rule); }
}

/* ---------- Current work (LM26) ---------- */

/* A navy blueprint sheet: the colour tokens are redefined for everything inside it. */
.feature {
  --paper: #0e1a2b;
  --ink: #e6edf5;
  --graphite: #9fb0c4;
  --rule: rgb(230 237 245 / 0.14);
  --strong-rule: rgb(230 237 245 / 0.55);
  --accent: #6fd3e8;
  --on-accent: #0b1726;
  --grid-minor: rgb(111 211 232 / 0.04);
  --grid-major: rgb(111 211 232 / 0.08);
  background: var(--grid), var(--paper);
  color: var(--ink);
}
.feature .wrap { display: grid; grid-template-columns: minmax(0, 5fr) minmax(0, 6fr); gap: clamp(32px, 6vw, 88px); align-items: center; }
.feature figure { margin: 0; }
.feature figure img { width: 100%; aspect-ratio: 1172 / 1106; object-fit: cover; border-radius: var(--radius); }
.feature figcaption { color: var(--graphite); font-size: 0.85rem; margin-top: 10px; }
.feature .kicker { color: var(--accent); margin-bottom: 0.9rem; }
.feature h2 { margin-bottom: 1.4rem; }
.feature p { max-width: var(--measure); }
.facts { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 0; margin: 2rem 0; border-top: 1px solid var(--rule); }
.facts div { padding: 14px 16px 14px 0; border-bottom: 1px solid var(--rule); }
.facts div:nth-child(2n) { padding-left: 16px; border-left: 1px solid var(--rule); }
.facts dt { font-size: 1.6rem; font-weight: 500; line-height: 1.2; letter-spacing: -0.02em; color: var(--accent); }
.facts dd { margin: 4px 0 0; color: var(--graphite); font-size: 0.92rem; line-height: 1.45; }
.feature .actions { display: flex; flex-wrap: wrap; gap: 12px 28px; align-items: center; }
@media (max-width: 700px) { .feature .wrap { grid-template-columns: 1fr; } .feature figure { max-width: 480px; } }
@media (max-width: 420px) { .facts { grid-template-columns: 1fr; } .facts div:nth-child(2n) { padding-left: 0; border-left: 0; } }

/* ---------- Work ---------- */

.filters { display: flex; flex-wrap: wrap; gap: 8px; margin: -16px 0 36px; }
.filters button {
  font-family: var(--mono); font-size: 0.78rem; letter-spacing: 0.04em;
  padding: 7px 12px;
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  background: var(--paper);
  color: var(--ink);
  cursor: pointer;
}
.filters button:hover { border-color: var(--accent); color: var(--accent); }
.filters button[aria-pressed="true"] { background: var(--accent); border-color: var(--accent); color: var(--on-accent); }
.filters .count { color: inherit; opacity: 0.7; margin-left: 4px; font-variant-numeric: tabular-nums; }

.projects { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: clamp(28px, 3.5vw, 44px) clamp(20px, 2.5vw, 32px); }
@media (max-width: 960px) { .projects { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
@media (max-width: 560px) { .projects { grid-template-columns: 1fr; } }

.project { position: relative; }
.project[hidden] { display: none; }
.project .thumb {
  aspect-ratio: 4 / 3;
  overflow: hidden;
  border-radius: var(--radius);
  background: var(--surface);
  outline: 1px solid var(--rule);
  outline-offset: -1px;
  margin-bottom: 14px;
}
.project .thumb img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.4s ease; }
/* Renders and diagrams drawn on white keep a light sheet behind them. */
.project .thumb.contain { background: #ffffff; }
.project .thumb.contain img { object-fit: contain; padding: 6%; }
/* Square illustration on a navy field matched to its own edges. */
.project .thumb.navy { background: linear-gradient(90deg, #071a3a, #08224c); }
.project .thumb.navy img { object-fit: contain; }
.project:hover .thumb { outline-color: var(--accent); }
.project:hover .thumb img { transform: scale(1.025); }
@media (prefers-reduced-motion: reduce) { .project:hover .thumb img { transform: none; } }
.project .meta { color: var(--graphite); margin: 0 0 6px; }
.project h3 { margin-bottom: 8px; }
.project h3 button {
  all: unset;
  cursor: pointer;
}
.project h3 button::after { content: ""; position: absolute; inset: 0; }
.project h3 button:focus-visible { outline: none; }
.project:has(h3 button:focus-visible) .thumb { outline: 2px solid var(--accent); outline-offset: 2px; }
.project:hover h3 { color: var(--accent); }
.project > p:last-of-type { color: var(--graphite); font-size: 0.97rem; margin: 0; }
.project .detail { display: none; }

/* Section hatching stands in for projects without photographs. */
.thumb.hatched {
  display: grid; place-items: end start;
  padding: 18px 20px;
  background:
    repeating-linear-gradient(-45deg, transparent 0 9px, rgb(20 32 46 / 0.16) 9px 10px),
    var(--surface);
}
.thumb.hatched span {
  background: var(--paper);
  padding: 6px 10px;
  font-size: 1.05rem;
  line-height: 1.25;
  border: 1px solid var(--accent);
  max-width: 85%;
}

/* ---------- Project dialog ---------- */

dialog.project-dialog {
  width: min(1120px, calc(100vw - 32px));
  max-height: calc(100dvh - 32px);
  padding: 0;
  border: 1px solid var(--rule);
  border-top: 2px solid var(--accent);
  border-radius: var(--radius);
  background: var(--paper);
  color: var(--ink);
  overflow: hidden;
}
dialog.project-dialog::backdrop { background: rgb(4 9 16 / 0.72); backdrop-filter: blur(3px); }
dialog.project-dialog[open] { display: flex; flex-direction: column; }
@media (prefers-reduced-motion: no-preference) {
  dialog.project-dialog[open] { animation: rise 0.22s ease-out; }
}
@keyframes rise { from { opacity: 0; transform: translateY(12px); } }

.dialog-bar { display: flex; justify-content: space-between; align-items: start; gap: 16px; padding: 22px clamp(20px, 3vw, 36px) 18px; border-bottom: 1px solid var(--rule); }
.dialog-bar .meta { color: var(--accent); margin: 0 0 6px; }
.dialog-bar h2 { font-size: clamp(1.5rem, 2.6vw, 2.1rem); }
.close {
  flex: none;
  font-family: var(--mono); font-size: 0.78rem; letter-spacing: 0.08em; text-transform: uppercase;
  padding: 8px 14px;
  border: 1px solid var(--strong-rule);
  border-radius: var(--radius);
  background: transparent;
  color: var(--ink);
  cursor: pointer;
}
.close:hover { border-color: var(--accent); color: var(--accent); }
.dialog-body {
  overflow-y: auto;
  display: grid;
  grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
  gap: clamp(24px, 4vw, 48px);
  padding: clamp(20px, 3vw, 36px);
}
.dialog-text { font-size: 1rem; }
@media (min-width: 801px) { .dialog-text { position: sticky; top: 0; align-self: start; } }
.dialog-text .summary { font-size: 1.1rem; }
.dialog-text h3 { font-size: 1rem; margin: 1.6rem 0 0.5rem; }
.dialog-text ul { margin-bottom: 1rem; }
.dialog-text .links { list-style: none; padding: 0; }
.dialog-text .muted { font-family: var(--mono); font-size: 0.8rem; line-height: 1.7; }
.dialog-text .credit { color: var(--graphite); font-size: 0.88rem; margin-top: 1.5rem; }
.dialog-media { display: grid; gap: 22px; align-content: start; }
.dialog-media figure { margin: 0; }
.dialog-media img, .dialog-media video { width: 100%; height: auto; max-height: 72vh; object-fit: contain; border-radius: var(--radius); background: var(--surface); outline: 1px solid var(--rule); outline-offset: -1px; }
.dialog-media figcaption { color: var(--graphite); font-size: 0.88rem; margin-top: 8px; }
.dialog-media .hatched { aspect-ratio: 16 / 9; border-radius: var(--radius); outline: 1px solid var(--rule); outline-offset: -1px; }
@media (max-width: 800px) { .dialog-body { grid-template-columns: 1fr; } .dialog-media { order: -1; } }

/* ---------- Experience ---------- */

.timeline { list-style: none; padding: 0; margin: 0; border-top: 1.5px solid var(--accent); }
.timeline > li { display: grid; grid-template-columns: 11rem minmax(0, 1fr); gap: 8px 32px; padding: 28px 0; border-bottom: 1px solid var(--rule); margin: 0; }
.timeline time { color: var(--accent); font-family: var(--mono); font-size: 0.85rem; font-variant-numeric: tabular-nums; padding-top: 4px; }
.timeline h3 { margin-bottom: 2px; }
.timeline .org { color: var(--graphite); margin-bottom: 12px; }
.timeline ul { max-width: var(--measure); }
.timeline .brk h3 { font-weight: 400; }
@media (max-width: 700px) { .timeline > li { grid-template-columns: 1fr; } }

.credentials { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 32px; margin-top: clamp(48px, 7vw, 80px); }
.credentials h3 { margin-bottom: 8px; }
.credentials p { color: var(--graphite); font-size: 0.97rem; }
@media (max-width: 860px) { .credentials { grid-template-columns: 1fr; gap: 20px; } }

/* ---------- Open source ---------- */

.repos { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 0; list-style: none; padding: 0; margin: 0; border-top: 1.5px solid var(--accent); }
.repos li { margin: 0; padding: 20px 24px 20px 0; border-bottom: 1px solid var(--rule); }
.repos li:not(:nth-child(3n + 1)) { padding-left: 24px; border-left: 1px solid var(--rule); }
.repos a { font-family: var(--mono); font-size: 0.95rem; font-weight: 500; }
.repos .lang { color: var(--graphite); font-family: var(--mono); font-size: 0.72rem; letter-spacing: 0.06em; text-transform: uppercase; margin-left: 8px; }
.repos p { color: var(--graphite); font-size: 0.95rem; margin: 6px 0 0; }
@media (max-width: 960px) {
  .repos { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .repos li:not(:nth-child(3n + 1)) { padding-left: 0; border-left: 0; }
  .repos li:nth-child(2n) { padding-left: 24px; border-left: 1px solid var(--rule); }
}
@media (max-width: 560px) {
  .repos { grid-template-columns: 1fr; }
  .repos li:nth-child(2n) { padding-left: 0; border-left: 0; }
}

/* ---------- About ---------- */

.about { display: grid; grid-template-columns: minmax(0, 4fr) minmax(0, 7fr); gap: clamp(32px, 6vw, 88px); align-items: start; }
.about img { width: 100%; aspect-ratio: 4 / 5; object-fit: cover; object-position: 50% 30%; border-radius: var(--radius); outline: 1px solid var(--rule); outline-offset: 6px; }
.about h2 { margin-bottom: 1.5rem; }
.about p { max-width: var(--measure); }
@media (max-width: 760px) { .about { grid-template-columns: 1fr; } .about img { max-width: 320px; } }

/* ---------- Contact ---------- */

.contact {
  background: var(--grid), var(--deep);
  border-top: 1px solid var(--rule);
}
.contact .wrap { max-width: var(--max); }
.contact h2 { margin-bottom: 1.2rem; }
.contact p { max-width: 40em; font-size: 1.1rem; }
.contact .actions { display: flex; flex-wrap: wrap; gap: 12px; }

/* ---------- 404 page ---------- */

/* The hero, alone: it fills the window between the top bar and the footer. */
.notfound-page { display: flex; flex-direction: column; min-height: 100dvh; }
.hero.notfound { flex: 1; display: flex; align-items: center; border-bottom: 0; }
.hero.notfound .wrap { width: 100%; grid-template-columns: minmax(0, 1fr); grid-template-areas: "text" "links"; }

footer.site { padding-block: 28px 40px; color: var(--graphite); font-size: 0.85rem; background: var(--deep); }
footer.site .wrap { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 8px 32px; }
footer.site p { margin: 0; max-width: 70ch; }