/* ==========================================================================
   KB0RB.net — hand-rolled stylesheet
   Colour tokens carry over the HSL palette from the previous site.
   ========================================================================== */

:root,
[data-theme="dark"] {
  --background:        222 84% 5%;
  --surface:           222 47% 9%;
  --surface-raised:    217 33% 13%;
  --foreground:        210 40% 98%;
  --muted-foreground:  215 20% 65%;
  --primary:           217 91% 60%;
  --primary-soft:      217 91% 60%;
  --primary-contrast:  222 47% 11%;
  --border:            217 33% 18%;
  --shadow: 0 1px 2px hsl(222 84% 2% / .4), 0 12px 32px -12px hsl(222 84% 2% / .6);
  --glow: radial-gradient(60rem 32rem at 78% -10%, hsl(217 91% 60% / .16), transparent 60%);
}

[data-theme="light"] {
  --background:        210 40% 98%;
  --surface:           0 0% 100%;
  --surface-raised:    210 40% 96%;
  --foreground:        222 84% 5%;
  --muted-foreground:  215 16% 47%;
  --primary:           221 83% 53%;
  --primary-soft:      221 83% 53%;
  --primary-contrast:  210 40% 98%;
  --border:            214 32% 91%;
  --shadow: 0 1px 2px hsl(222 40% 40% / .06), 0 12px 32px -16px hsl(222 40% 30% / .18);
  --glow: radial-gradient(60rem 32rem at 78% -10%, hsl(221 83% 53% / .10), transparent 60%);
}

:root {
  --font-sans: "SF Pro Display", -apple-system, BlinkMacSystemFont, "Inter", system-ui, sans-serif;
  --font-mono: "SF Mono", "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
  --radius: 0.75rem;
  --radius-sm: 0.5rem;
  --wrap: 68rem;
  --header-h: 4rem;
}

/* --- reset ---------------------------------------------------------------- */

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 1rem);
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.65;
  color: hsl(var(--foreground));
  background-color: hsl(var(--background));
  background-image: var(--glow);
  background-repeat: no-repeat;
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

h1, h2, h3, h4 {
  line-height: 1.2;
  letter-spacing: -0.02em;
  font-weight: 700;
  margin: 0 0 0.5em;
  text-wrap: balance;
}

h1 { font-size: clamp(2rem, 1.4rem + 2.6vw, 3.25rem); }
h2 { font-size: clamp(1.5rem, 1.25rem + 1.1vw, 2rem); }
h3 { font-size: 1.2rem; }

p { margin: 0 0 1rem; }

a {
  color: hsl(var(--primary));
  text-decoration-color: hsl(var(--primary) / .35);
  text-underline-offset: 3px;
  transition: color .15s ease, text-decoration-color .15s ease;
}
a:hover { text-decoration-color: hsl(var(--primary)); }

code, kbd, .mono { font-family: var(--font-mono); font-size: .92em; }

:focus-visible {
  outline: 2px solid hsl(var(--primary));
  outline-offset: 2px;
  border-radius: 4px;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  z-index: 100;
  padding: .6rem 1rem;
  background: hsl(var(--surface));
  border: 1px solid hsl(var(--border));
  border-radius: var(--radius-sm);
}
.skip-link:focus { left: 1rem; top: 1rem; }

.icon { width: 1.25em; height: 1.25em; flex: none; }

/* --- layout --------------------------------------------------------------- */

.wrap {
  width: min(100% - 2.5rem, var(--wrap));
  margin-inline: auto;
}

main { padding-bottom: 5rem; }

.section { padding-block: clamp(3rem, 8vw, 5rem); }
.section + .section { border-top: 1px solid hsl(var(--border)); }

.section-head { margin-bottom: 2rem; }
.section-head h2 { margin-bottom: .35rem; }
.section-head .rule {
  width: 3rem; height: 3px; border-radius: 2px;
  background: hsl(var(--primary));
  margin-bottom: 1.25rem;
}

.lead {
  font-size: clamp(1.05rem, 1rem + .3vw, 1.25rem);
  color: hsl(var(--foreground) / .82);
  max-width: 46rem;
}

.muted { color: hsl(var(--muted-foreground)); }

/* --- header --------------------------------------------------------------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: hsl(var(--background) / .72);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color .2s ease, background-color .2s ease;
}
.site-header.is-scrolled { border-bottom-color: hsl(var(--border)); }

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  height: var(--header-h);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  font-weight: 600;
  color: hsl(var(--primary));
  text-decoration: none;
  letter-spacing: .02em;
}
.brand-call { font-family: var(--font-mono); font-size: 1.05rem; }

.nav { display: flex; align-items: center; gap: 1.75rem; }
.nav a {
  color: hsl(var(--foreground) / .78);
  text-decoration: none;
  font-size: .95rem;
  position: relative;
  padding-block: .25rem;
}
.nav a:hover { color: hsl(var(--primary)); }
.nav a.is-active { color: hsl(var(--foreground)); }
.nav a.is-active::after {
  content: "";
  position: absolute;
  left: 0; right: 0; bottom: -2px;
  height: 2px; border-radius: 2px;
  background: hsl(var(--primary));
}

.header-actions { display: flex; align-items: center; gap: .5rem; }

.icon-btn {
  display: inline-grid;
  place-items: center;
  width: 2.25rem; height: 2.25rem;
  padding: 0;
  border-radius: 999px;
  border: 1px solid hsl(var(--border));
  background: hsl(var(--surface) / .6);
  color: hsl(var(--foreground) / .8);
  cursor: pointer;
  transition: color .15s ease, border-color .15s ease, background-color .15s ease;
}
.icon-btn:hover { color: hsl(var(--primary)); border-color: hsl(var(--primary) / .5); }

.nav-toggle { display: none; }
.nav-icon-close { display: none; }
[data-theme="dark"] .theme-icon-light { display: none; }
[data-theme="light"] .theme-icon-dark { display: none; }

@media (max-width: 47.9375em) {
  .nav-toggle { display: inline-grid; }
  .nav {
    position: absolute;
    top: 100%; left: 0; right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: .5rem 1.25rem 1rem;
    background: hsl(var(--background));
    border-bottom: 1px solid hsl(var(--border));
    box-shadow: var(--shadow);
    display: none;
  }
  .nav.is-open { display: flex; }
  .nav a { padding: .75rem 0; border-bottom: 1px solid hsl(var(--border)); }
  .nav a:last-child { border-bottom: 0; }
  .nav a.is-active { color: hsl(var(--primary)); font-weight: 500; }
  .nav a.is-active::after { display: none; }
  .nav-toggle[aria-expanded="true"] .nav-icon-open { display: none; }
  .nav-toggle[aria-expanded="true"] .nav-icon-close { display: block; }
}

/* --- hero ----------------------------------------------------------------- */

.hero {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(2rem, 5vw, 3.5rem);
  align-items: center;
  padding-block: clamp(2.5rem, 7vw, 4.5rem);
}

@media (min-width: 56em) {
  .hero { grid-template-columns: 1.15fr .85fr; }
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  padding: .3rem .75rem;
  border-radius: 999px;
  background: hsl(var(--primary) / .12);
  color: hsl(var(--primary));
  border: 1px solid hsl(var(--primary) / .2);
  font-size: .82rem;
  font-weight: 500;
  letter-spacing: .01em;
  margin-bottom: 1.25rem;
}
.eyebrow .icon { width: 1rem; height: 1rem; }

.hero h1 { margin-bottom: .75rem; }
.hero h1 .call {
  color: hsl(var(--primary));
  font-family: var(--font-mono);
  letter-spacing: -0.01em;
}

.hero-photo {
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid hsl(var(--border));
  box-shadow: var(--shadow);
}
.hero-photo img { width: 100%; }

/* --- buttons -------------------------------------------------------------- */

.btn-row { display: flex; flex-wrap: wrap; gap: .75rem; margin: 1.75rem 0 2rem; }
.hero .btn-row { margin-bottom: 0; }

.btn {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  height: 2.6rem;
  padding-inline: 1.4rem;
  border-radius: var(--radius-sm);
  border: 1px solid hsl(var(--border));
  background: hsl(var(--surface) / .7);
  color: hsl(var(--foreground));
  font-size: .95rem;
  font-weight: 500;
  text-decoration: none;
  cursor: pointer;
  transition: background-color .15s ease, border-color .15s ease, transform .15s ease;
}
.btn:hover { border-color: hsl(var(--primary) / .55); transform: translateY(-1px); }
.btn .icon { width: 1rem; height: 1rem; }

.btn-primary {
  background: hsl(var(--primary));
  border-color: hsl(var(--primary));
  color: hsl(var(--primary-contrast));
  font-weight: 600;
}
.btn-primary:hover { background: hsl(var(--primary) / .9); }

/* --- cards ---------------------------------------------------------------- */

.card {
  background: hsl(var(--surface) / .75);
  border: 1px solid hsl(var(--border));
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.card-pad { padding: clamp(1.25rem, 3vw, 1.75rem); }

.card-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1.25rem clamp(1.25rem, 3vw, 1.75rem) 0;
}
.card-head h2 { font-size: 1.35rem; margin: 0; }
.card-head .icon { color: hsl(var(--primary)); }
.card-sub {
  margin: .15rem 0 0;
  padding: 0 clamp(1.25rem, 3vw, 1.75rem);
  color: hsl(var(--muted-foreground));
  font-size: .95rem;
}

.card-foot {
  padding: .85rem 1.25rem;
  border-top: 1px solid hsl(var(--border));
  background: hsl(var(--surface-raised) / .5);
  border-radius: 0 0 var(--radius) var(--radius);
  text-align: center;
  color: hsl(var(--muted-foreground));
  font-size: .9rem;
}
.card-foot p { margin: 0; }

/* --- contact grid --------------------------------------------------------- */

.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(15rem, 1fr));
  gap: 1.25rem 1.5rem;
  padding: 1.25rem clamp(1.25rem, 3vw, 1.75rem) 1.5rem;
}

.contact-item { display: flex; align-items: center; gap: .85rem; }
.contact-item-wide { align-items: flex-start; grid-column: 1 / -1; }
.contact-item-wide .bubble { margin-top: .1rem; }

.contact-item .bubble {
  display: grid;
  place-items: center;
  width: 2.5rem; height: 2.5rem;
  flex: none;
  border-radius: 999px;
  background: hsl(var(--primary) / .12);
  color: hsl(var(--primary));
}
.contact-item .label {
  display: block;
  font-size: .8rem;
  color: hsl(var(--muted-foreground));
  line-height: 1.3;
}
.contact-item .value {
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: .3rem;
  color: hsl(var(--foreground));
  text-decoration: none;
}
.contact-item .value.mono { font-family: var(--font-mono); letter-spacing: .01em; }
a.value:hover { color: hsl(var(--primary)); }
a.value .icon { width: .85rem; height: .85rem; opacity: .7; }

.pill-row { display: flex; flex-wrap: wrap; gap: .5rem; margin-top: .35rem; }
.pill {
  display: inline-flex;
  align-items: center;
  padding: .25rem .7rem;
  border-radius: 999px;
  background: hsl(var(--primary) / .1);
  color: hsl(var(--primary));
  font-size: .85rem;
  text-decoration: none;
  transition: background-color .15s ease;
}
.pill:hover { background: hsl(var(--primary) / .2); }

/* --- split section (sticky heading + content) ----------------------------- */

.split { display: grid; gap: 2rem; }

@media (min-width: 62em) {
  .split { grid-template-columns: 15rem 1fr; gap: 3rem; }
  .split-aside { position: sticky; top: calc(var(--header-h) + 2rem); align-self: start; }
}

.split-aside h2 { margin-bottom: .75rem; }
.split-aside .rule {
  width: 3rem; height: 3px; border-radius: 2px;
  background: hsl(var(--primary));
  margin-bottom: 1.25rem;
}
.split-links { display: none; flex-direction: column; gap: .6rem; }
.split-links a { color: hsl(var(--muted-foreground)); text-decoration: none; font-size: .95rem; }
.split-links a:hover { color: hsl(var(--primary)); }
@media (min-width: 62em) { .split-links { display: flex; } }

/* --- equipment ------------------------------------------------------------ */

.equipment-grid {
  display: grid;
  gap: 1.25rem;
  grid-template-columns: repeat(auto-fit, minmax(17rem, 1fr));
}

.equipment-card { display: flex; flex-direction: column; height: 100%; transition: border-color .2s ease, transform .2s ease; }
.equipment-card:hover { border-color: hsl(var(--primary) / .4); transform: translateY(-2px); }

.equipment-card h3 { display: flex; align-items: center; gap: .75rem; margin-bottom: 1rem; font-size: 1.05rem; }
.equipment-card h3 .bubble {
  display: grid; place-items: center;
  width: 2.25rem; height: 2.25rem;
  border-radius: 999px;
  background: hsl(var(--primary) / .12);
  color: hsl(var(--primary));
}

.tick-list { list-style: none; margin: 0; padding: 0; display: grid; gap: .55rem; }
.tick-list li { display: flex; gap: .7rem; color: hsl(var(--foreground) / .85); font-size: .95rem; line-height: 1.5; }
.tick-list li::before {
  content: "";
  flex: none;
  width: .375rem; height: .375rem;
  margin-top: .6rem;
  border-radius: 999px;
  background: hsl(var(--primary));
}

/* --- projects ------------------------------------------------------------- */

.project-grid {
  display: grid;
  gap: 1.25rem;
  grid-template-columns: repeat(auto-fit, minmax(19rem, 1fr));
}

/* A card holds more than one link (title, App Store badge, call to action),
   so it is a container rather than a single anchor. */
.project-card {
  display: flex;
  flex-direction: column;
  gap: .85rem;
  padding: clamp(1.25rem, 3vw, 1.6rem);
  color: inherit;
  transition: border-color .2s ease, transform .2s ease;
}
.project-card:hover,
.project-card:focus-within { border-color: hsl(var(--primary) / .45); transform: translateY(-2px); }

.project-card h3 a {
  color: inherit;
  text-decoration: none;
}
.project-card h3 a:hover { color: hsl(var(--primary)); }

.project-card .bubble {
  display: grid; place-items: center;
  width: 2.5rem; height: 2.5rem;
  border-radius: var(--radius-sm);
  background: hsl(var(--primary) / .12);
  color: hsl(var(--primary));
}

/* App icons ship as full-bleed squares, so round them here rather than
   depending on each source image having its own corners. */
.app-icon {
  width: 3rem;
  height: 3rem;
  flex: none;
  border-radius: 22.37%; /* Apple's squircle proportion, near enough */
  object-fit: cover;
  box-shadow: 0 1px 3px hsl(222 84% 2% / .3), 0 0 0 1px hsl(var(--border));
}

.app-icon-lg {
  width: 4rem;
  height: 4rem;
  margin-top: .35rem;
}

@media (min-width: 40em) {
  .app-icon-lg { width: 5rem; height: 5rem; }
}
.project-card h3 { margin: 0; font-size: 1.15rem; }
.project-card .tagline { margin: 0; color: hsl(var(--primary)); font-size: .9rem; font-weight: 500; }
.project-card p.summary { margin: 0; color: hsl(var(--muted-foreground)); font-size: .95rem; flex: 1; }

.tag-row { display: flex; flex-wrap: wrap; gap: .4rem; margin: .25rem 0 0; }
.tag {
  display: inline-flex;
  align-items: center;
  padding: .2rem .6rem;
  border-radius: 999px;
  border: 1px solid hsl(var(--border));
  background: hsl(var(--surface-raised) / .6);
  color: hsl(var(--muted-foreground));
  font-size: .78rem;
  letter-spacing: .01em;
}
.tag-status { border-color: hsl(var(--primary) / .3); background: hsl(var(--primary) / .1); color: hsl(var(--primary)); }

.card-cta {
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  font-size: .9rem;
  font-weight: 500;
  color: hsl(var(--primary));
  text-decoration: none;
  margin-top: auto;
  align-self: flex-start;
}
.card-cta:hover { text-decoration: underline; text-underline-offset: 3px; }
.card-cta .icon { width: 1rem; height: 1rem; transition: transform .2s ease; }
.project-card:hover .card-cta .icon { transform: translateX(3px); }

/* Apple's badge is a fixed-proportion asset — size it by height only and
   never recolour or crop it. */
.appstore-badge {
  display: inline-block;
  align-self: flex-start;
  line-height: 0;
  border-radius: 8px;
  transition: opacity .15s ease;
}
.appstore-badge:hover { opacity: .85; }
.appstore-badge img {
  height: 2.5rem;
  width: auto;
}
[data-theme="dark"] .appstore-badge .badge-on-light,
[data-theme="light"] .appstore-badge .badge-on-dark { display: none; }
.project-head .appstore-badge { margin-top: .35rem; }

/* --- page heads, breadcrumbs, prose --------------------------------------- */

.page-head { padding-block: clamp(2.5rem, 6vw, 3.5rem) 1.5rem; }
.page-head h1 { margin-bottom: .5rem; }

.project-head { display: flex; gap: 1.25rem; align-items: flex-start; }
.project-head-icon {
  display: grid; place-items: center;
  width: 3.25rem; height: 3.25rem;
  flex: none;
  margin-top: .35rem;
  border-radius: var(--radius);
  background: hsl(var(--primary) / .12);
  color: hsl(var(--primary));
}
.project-head-icon .icon { width: 1.6rem; height: 1.6rem; }

.breadcrumb {
  padding-top: 1.5rem;
  margin: 0;
  font-size: .875rem;
  color: hsl(var(--muted-foreground));
}
.breadcrumb a { text-decoration: none; }
.breadcrumb span { margin-inline: .4rem; opacity: .5; }

.effective { color: hsl(var(--muted-foreground)); font-size: .9rem; margin-top: .75rem; }

.prose { max-width: 46rem; }
.prose > :first-child { margin-top: 0; }
.prose h2 { margin-top: 2.5rem; }
.prose h3 { margin-top: 1.75rem; }
.prose ul, .prose ol { padding-left: 1.25rem; margin: 0 0 1rem; }
.prose li { margin-bottom: .4rem; }
.prose li::marker { color: hsl(var(--primary)); }
.prose blockquote {
  margin: 1.5rem 0;
  padding: .25rem 0 .25rem 1.25rem;
  border-left: 3px solid hsl(var(--primary) / .5);
  color: hsl(var(--muted-foreground));
}
.prose code {
  padding: .15em .4em;
  border-radius: 4px;
  background: hsl(var(--surface-raised));
  border: 1px solid hsl(var(--border));
}
.prose hr { border: 0; border-top: 1px solid hsl(var(--border)); margin: 2.5rem 0; }
.prose table { width: 100%; border-collapse: collapse; margin: 1.5rem 0; font-size: .95rem; }
.prose th, .prose td { text-align: left; padding: .6rem .75rem; border-bottom: 1px solid hsl(var(--border)); }
.prose th { color: hsl(var(--muted-foreground)); font-weight: 600; font-size: .85rem; text-transform: uppercase; letter-spacing: .04em; }

.prose-legal { max-width: 44rem; }
.prose-legal h2 { font-size: 1.3rem; margin-top: 2.25rem; }

.link-list { list-style: none; padding: 0; }
.link-list a { display: inline-flex; align-items: center; gap: .5rem; text-decoration: none; }
.link-list a:hover { text-decoration: underline; }

.callout {
  display: flex;
  gap: .9rem;
  padding: 1.1rem 1.25rem;
  margin: 1.75rem 0;
  border: 1px solid hsl(var(--primary) / .3);
  background: hsl(var(--primary) / .08);
  border-radius: var(--radius-sm);
}
.callout .icon { color: hsl(var(--primary)); margin-top: .2rem; }
.callout > div > :last-child { margin-bottom: 0; }

/* --- footer --------------------------------------------------------------- */

.site-footer {
  border-top: 1px solid hsl(var(--border));
  padding-block: 3rem 2.5rem;
  margin-top: auto;
}

.footer-top {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
}
.footer-nav { display: flex; flex-wrap: wrap; gap: 1.5rem; }
.footer-nav a { color: hsl(var(--foreground) / .7); text-decoration: none; font-size: .95rem; }
.footer-nav a:hover { color: hsl(var(--primary)); }
.footer-copy { margin: 0; font-size: .875rem; color: hsl(var(--muted-foreground)); }

.footer-bottom {
  margin-top: 2rem;
  padding-top: 1.5rem;
  border-top: 1px solid hsl(var(--border));
  text-align: center;
  font-size: .875rem;
  color: hsl(var(--muted-foreground));
}
.footer-bottom a { color: inherit; text-decoration: none; }
.footer-bottom a:hover { color: hsl(var(--primary)); }
.footer-bottom p { margin: 0 0 .35rem; }
.memberships .sep { margin-inline: .6rem; opacity: .5; }
.grid-note { font-size: .82rem; opacity: .8; }

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

.notfound { text-align: center; padding-block: clamp(4rem, 14vw, 8rem); }
.notfound .code {
  font-family: var(--font-mono);
  font-size: clamp(3rem, 12vw, 6rem);
  color: hsl(var(--primary));
  line-height: 1;
  margin-bottom: 1rem;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .01ms !important;
    transition-duration: .01ms !important;
  }
}