/* =====================================================================
   Ole Köster — portfolio
   Concept: "the self-taught engineer's logbook."
   Signature: section labels rendered as code comments (// about) in mono.
   Palette: cool paper + deep navy + a single disciplined teal accent.
   ===================================================================== */

:root {
  --paper: #f4f6f8;
  --surface: #ffffff;
  --ink: #16212b;
  --ink-soft: #3b4855;
  --muted: #5c6878;
  --navy: #1b2b47;
  --navy-deep: #12203a;
  --teal: #0f6f79;
  --teal-ink: #0b565e; /* darker teal for text on light bg (AA) */
  --teal-light: #5fc2cc; /* teal for use on the dark band */
  --teal-tint: #dcebed; /* offset block behind the portrait */
  --line: #e2e6ec;
  --line-strong: #d2d9e1;

  --serif: "Newsreader", Georgia, "Times New Roman", serif;
  --sans:
    "Inter", system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial,
    sans-serif;
  --mono:
    "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  --wrap: 1120px;
  --radius: 12px;
  --radius-sm: 6px;
}

/* ---------- reset / base ---------- */
*,
*::before,
*::after {
  box-sizing: border-box;
}
* {
  margin: 0;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--sans);
  color: var(--ink);
  background: var(--paper);
  line-height: 1.65;
  font-size: 1rem;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img {
  max-width: 100%;
  display: block;
}
a {
  color: inherit;
}
ul,
ol {
  list-style: none;
  padding: 0;
}

h1,
h2,
h3 {
  font-family: var(--serif);
  font-weight: 500;
  line-height: 1.1;
  color: var(--navy);
  letter-spacing: -0.012em;
}

/* ---------- layout helpers ---------- */
.wrap {
  width: min(100% - 2.5rem, var(--wrap));
  margin-inline: auto;
}
.wrap.measure {
  width: min(100% - 2.5rem, 760px);
}

section:not(:first-child) {
  border-top: 1px solid var(--line);
}

.section {
  position: relative;
  padding-block: clamp(3.5rem, 8vw, 7rem);
}
section[id] {
  scroll-margin-top: 84px;
}

.section-title {
  font-size: clamp(1.9rem, 3.6vw, 2.7rem);
  margin-bottom: 1.4rem;
}
.section-intro {
  color: var(--ink-soft);
  max-width: 60ch;
  font-size: 1.08rem;
  margin-bottom: 2.4rem;
}

/* ---------- signature: code-comment eyebrows ---------- */
.eyebrow {
  font-family: var(--mono);
  font-size: 0.8rem;
  font-weight: 500;
  letter-spacing: 0.03em;
  color: var(--teal-ink);
  margin-bottom: 1rem;
}
.eyebrow::before {
  content: "// ";
  color: var(--teal);
}
.eyebrow--light {
  color: var(--teal-light);
}
.eyebrow--light::before {
  color: var(--teal-light);
}

/* ---------- skip link / focus ---------- */
.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  z-index: 100;
  background: var(--navy);
  color: #fff;
  padding: 0.6rem 1rem;
  border-radius: var(--radius-sm);
}
.skip-link:focus {
  left: 1rem;
  top: 1rem;
}
:focus-visible {
  outline: 2px solid var(--teal);
  outline-offset: 3px;
  border-radius: 3px;
}

/* ---------- header / nav ---------- */
.glass-filter-defs {
  position: absolute;
  width: 0;
  height: 0;
  overflow: hidden;
}

.site-header {
  margin: 12px 12px 0 12px;
  border-radius: var(--radius-sm);
  position: sticky;
  top: 12px;
  z-index: 50;
  background: linear-gradient(
    180deg,
    rgba(247, 249, 250, 0.5),
    rgba(244, 246, 248, 0.38)
  );
  /* Safari / Firefox fallback: frosted glass, no distortion (they don't support filter refs here) */
  -webkit-backdrop-filter: saturate(160%) blur(8px);
  /* Chromium: refractive liquid-glass distortion of whatever scrolls behind the header */
  backdrop-filter: url(#liquid-glass) brightness(1.1) blur(2px);
  /* box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.55); */
  filter: drop-shadow(-8px -10px 46px #0000005f);
}

@supports not (backdrop-filter: blur(1px)) {
  .site-header {
    background: rgba(244, 246, 248, 0.94);
  }
}
.nav {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  height: 64px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  text-decoration: none;
  color: var(--navy);
}
.brand-mark {
  font-family: var(--mono);
  font-weight: 500;
  font-size: 0.85rem;
  letter-spacing: 0.02em;
  width: 30px;
  height: 30px;
  display: grid;
  place-items: center;
  background: var(--navy);
  color: #fff;
  border-radius: var(--radius-sm);
}
.brand-name {
  font-family: var(--serif);
  font-size: 1.08rem;
  letter-spacing: 0.01em;
}

.nav-links {
  display: flex;
  gap: 1.4rem;
  margin-inline: auto;
}
.nav-links a {
  position: relative;
  font-size: 0.92rem;
  color: var(--ink-soft);
  text-decoration: none;
  padding: 0.25rem 0;
  transition: color 0.2s;
}
.nav-links a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -2px;
  height: 2px;
  width: 0;
  background: var(--teal);
  transition: width 0.25s ease;
}
.nav-links a:hover {
  color: var(--navy);
}
.nav-links a:hover::after,
.nav-links a:focus-visible::after {
  width: 100%;
}

.nav-meta {
  display: flex;
  align-items: center;
  gap: 1rem;
}
.pill {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  font-family: var(--mono);
  font-size: 0.76rem;
  color: var(--teal-ink);
  border: 1px solid var(--line-strong);
  background: var(--surface);
  padding: 0.3rem 0.65rem;
  border-radius: 999px;
  white-space: nowrap;
}
.pill-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--teal);
  animation: pulse 2.6s infinite;
}
.lang {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-family: var(--mono);
  font-size: 0.8rem;
}
.lang-btn {
  background: none;
  border: none;
  cursor: pointer;
  color: var(--muted);
  padding: 0.15rem 0.2rem;
  font: inherit;
  transition: color 0.2s;
}
.lang-btn:hover {
  color: var(--navy);
}
.lang-btn.is-active {
  color: var(--navy);
  font-weight: 500;
  text-decoration: underline;
  text-underline-offset: 4px;
  text-decoration-color: var(--teal);
}
.lang-sep {
  color: var(--line-strong);
}

@keyframes pulse {
  0% {
    box-shadow: 0 0 0 0 rgba(15, 111, 121, 0.45);
  }
  70% {
    box-shadow: 0 0 0 6px rgba(15, 111, 121, 0);
  }
  100% {
    box-shadow: 0 0 0 0 rgba(15, 111, 121, 0);
  }
}

/* ---------- hero ---------- */
.hero {
  padding-top: clamp(3rem, 7vw, 5.5rem);
}
.hero-grid {
  display: grid;
  grid-template-columns: 1.25fr 0.85fr;
  gap: clamp(2rem, 5vw, 4rem);
  align-items: center;
}
.hero-name {
  font-size: clamp(2.8rem, 7vw, 4.6rem);
  font-weight: 600;
  letter-spacing: -0.025em;
  line-height: 1.02;
}
.hero-lead {
  font-family: var(--serif);
  font-style: italic;
  font-weight: 400;
  font-size: clamp(1.5rem, 3.2vw, 2.15rem);
  color: var(--ink);
  margin: 0.5rem 0 1.1rem;
}
.hero-support {
  max-width: 46ch;
  color: var(--ink-soft);
  font-size: 1.06rem;
}
.hero-cta {
  display: flex;
  gap: 0.8rem;
  flex-wrap: wrap;
  margin: 1.7rem 0 1.4rem;
}
.hero-social {
  display: contents;
}

.hero-social li {
  display: flex;
}

.hero-social a {
  color: var(--muted);
  display: inline-flex;
  transition:
    color 0.2s,
    transform 0.2s;
}
.hero-social a:hover {
  color: var(--navy);
  transform: translateY(-2px);
}

.hero-portrait {
  position: relative;
  width: fit-content;
  margin-inline: auto;
}
.hero-portrait img {
  width: 100%;
  height: auto;
  max-width: 340px;
  border-radius: var(--radius);
  border: 1px solid var(--line-strong);
  background: var(--surface);
  box-shadow:
    0 1px 2px rgba(20, 33, 55, 0.06),
    16px 16px 0 -1px var(--teal-tint);
}
.portrait-note {
  font-family: var(--mono);
  font-size: 0.7rem;
  color: var(--muted);
  text-align: center;
  margin-top: 1.3rem;
}
.portrait-note code {
  color: var(--teal-ink);
}

/* ---------- buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--sans);
  font-weight: 500;
  font-size: 0.98rem;
  padding: 0.72rem 1.3rem;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  cursor: pointer;
  text-decoration: none;
  transition:
    transform 0.15s ease,
    background 0.2s,
    border-color 0.2s,
    color 0.2s;
}
.btn-primary {
  background: var(--navy);
  color: #fff;
}
.btn-primary:hover {
  background: var(--navy-deep);
  transform: translateY(-1px);
}
.btn-ghost {
  background: transparent;
  color: var(--navy);
  border-color: var(--line-strong);
}
.btn-ghost:hover {
  border-color: var(--navy);
  transform: translateY(-1px);
}

/* ---------- about ---------- */
.prose p {
  font-size: 1.12rem;
  color: var(--ink-soft);
  max-width: 64ch;
  margin-bottom: 1.1rem;
}
.prose p:last-child {
  margin-bottom: 0;
}

/* ---------- skills ---------- */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.6rem 2rem;
}
.skill-title {
  font-family: var(--mono);
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--navy);
  letter-spacing: 0.02em;
  margin-bottom: 0.9rem;
}
.chips {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}
.chip {
  font-size: 0.86rem;
  color: var(--ink-soft);
  background: var(--surface);
  border: 1px solid var(--line-strong);
  padding: 0.32rem 0.66rem;
  border-radius: 999px;
}

/* ---------- projects ---------- */
.projects {
  display: flex;
  flex-direction: column;
  gap: 1.4rem;
}
.project {
  display: grid;
  gap: 0.85rem;
  position: relative;
  padding: 1.9rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: transparent;
}

.project.is-featured {
  background: var(--surface);
  box-shadow: 0 1px 2px rgba(20, 33, 55, 0.04);
}
.project.is-featured::before {
  content: "featured";
  position: absolute;
  top: 1.9rem;
  right: 1.9rem;
  font-family: var(--mono);
  font-size: 0.68rem;
  letter-spacing: 0.06em;
  color: var(--teal-ink);
  text-transform: uppercase;
}

.project-title {
  font-size: 1.4rem;
}
.project.is-featured .project-title {
  font-size: clamp(1.5rem, 2.6vw, 2rem);
}
.project-desc {
  color: var(--ink-soft);
  max-width: 68ch;
  font-size: 1.04rem;
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
}
.tags li {
  font-family: var(--mono);
  font-size: 0.73rem;
  color: var(--muted);
  border: 1px solid var(--line);
  background: var(--paper);
  border-radius: 5px;
  padding: 0.2rem 0.46rem;
}
.project-links {
  display: flex;
  flex-wrap: wrap;
  gap: 1.2rem;
}
.project-links a {
  font-family: var(--mono);
  font-size: 0.82rem;
  color: var(--teal-ink);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  transition: color 0.2s;
}
.project-links a::before {
  content: "↗";
  color: var(--teal);
}
.project-links a:hover {
  color: var(--navy);
}

/* ---------- vision (inverted band) ---------- */
.section--dark {
  background: linear-gradient(160deg, var(--navy) 0%, var(--navy-deep) 100%);
  color: #e7edf5;
}
.section--dark .section-title {
  color: #fff;
}
.vision-body {
  font-family: var(--serif);
  font-weight: 400;
  font-size: clamp(1.3rem, 2.6vw, 1.85rem);
  line-height: 1.5;
  color: #dce5f0;
  max-width: 38ch;
}

/* ---------- contact ---------- */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}
.contact-card {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  padding: 1.1rem 1.3rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  text-decoration: none;
  color: var(--ink);
  transition:
    border-color 0.2s,
    transform 0.15s ease,
    box-shadow 0.2s;
}
.contact-card:hover {
  border-color: var(--teal);
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(20, 33, 55, 0.07);
}
.contact-kind {
  font-family: var(--mono);
  font-size: 0.8rem;
  color: var(--teal-ink);
}
.contact-value {
  font-weight: 500;
  color: var(--navy);
}
.contact-card--primary {
  background: var(--navy);
  border-color: var(--navy);
}
.contact-card--primary .contact-kind {
  color: var(--teal-light);
}
.contact-card--primary .contact-value {
  color: #fff;
}
.contact-card--primary:hover {
  border-color: var(--teal-light);
}

/* ---------- privacy ---------- */
.privacy-section {
  border-top: 1px solid var(--line);
  background: var(--paper);
}
.privacy-copy {
  max-width: 72ch;
  color: var(--muted);
  line-height: 1.75;
}

/* ---------- footer ---------- */
.site-footer {
  position: relative;
  background: var(--paper);
  padding-block: 2.5rem;
}
.footer-inner {
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
  justify-content: space-between;
}
.footer-note {
  font-family: var(--mono);
  font-size: 0.8rem;
  color: var(--muted);
}
.footer-link {
  font-family: var(--mono);
  font-size: 0.8rem;
  color: var(--teal-ink);
  text-decoration: none;
}
.footer-link:hover {
  color: var(--navy);
  text-decoration: underline;
}
.footer-rights {
  font-size: 0.85rem;
  color: var(--muted);
}

/* ---------- scroll reveal (only when JS is on) ---------- */
.js .reveal {
  opacity: 0;
  transform: translateY(18px);
  transition:
    opacity 0.7s ease,
    transform 0.7s ease;
}
.js .reveal.is-visible {
  opacity: 1;
  transform: none;
}

/* ---------- responsive ---------- */
@media (max-width: 900px) {
  .hero-grid {
    grid-template-columns: 1fr;
  }
  .hero-portrait {
    margin-top: 1rem;
  }
  .hero-portrait img {
    max-width: 260px;
  }
  .vision-body {
    max-width: 100%;
  }
}
@media (max-width: 720px) {
  .nav-links {
    display: none;
  }
}
@media (max-width: 560px) {
  .pill {
    display: none;
  }
  .contact-card {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.3rem;
  }
}

/* ---------- reduced motion ---------- */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  *,
  *::before,
  *::after {
    animation: none !important;
    transition: none !important;
  }
  .js .reveal {
    opacity: 1 !important;
    transform: none !important;
  }
}