/* Sandra K — personal engineering site. Calm, text-forward, minimal. */

:root {
  --bg: var(--accent-soft);
  --bg-alt: #f7f7f8;
  --ink: #14161a;
  --muted: #5b6270;
  --border: #e6e8eb;
  --accent: #3f6b4f;
  --accent-ink: #ffffff;
  --accent-soft: #e8f3ea;
  --accent-soft-border: #cfe6d5;
  --code-bg: #14161a;
  --code-ink: #e6e8eb;
  --max: 760px;
  --max-wide: 1040px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0e0f13;
    --bg-alt: #16181d;
    --ink: #eef0f3;
    --muted: #9aa1ad;
    --border: #262a33;
    --accent: #5fbf8c;
    --accent-ink: #0b120d;
    --accent-soft: #182720;
    --accent-soft-border: #24382c;
    --code-bg: #090a0d;
    --code-ink: #d8dbe2;
  }
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Inter", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
  background: var(--accent);
  color: var(--accent-ink);
  padding: 0.6rem 1rem;
  z-index: 100;
}
.skip-link:focus { left: 0.5rem; top: 0.5rem; }

a {
  color: var(--accent);
  text-decoration: none;
}
a:hover { text-decoration: underline; }

h1, h2, h3, h4 {
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -0.01em;
}

code, pre {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

/* ── NAV ── */
.site-nav {
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  background: var(--bg);
  z-index: 10;
}

.nav-inner {
  max-width: var(--max-wide);
  margin: 0 auto;
  padding: 1.1rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.75rem 1.5rem;
}

.nav-brand {
  font-weight: 600;
  color: var(--ink);
  font-size: 1rem;
}
.nav-brand:hover { text-decoration: none; }

.nav-links {
  display: flex;
  gap: 1.5rem;
  flex-wrap: wrap;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-links a {
  color: var(--muted);
  font-size: 0.92rem;
}

.nav-links a:hover,
.nav-links a[aria-current="page"] {
  color: var(--ink);
  text-decoration: none;
}

.nav-links a[aria-current="page"] {
  border-bottom: 2px solid var(--accent);
  padding-bottom: 2px;
}

/* ── LAYOUT ── */
main {
  max-width: var(--max-wide);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.prose {
  max-width: var(--max);
  margin: 0 auto;
}

section {
  padding: 4rem 0;
}

section + section {
  border-top: 1px solid var(--accent-soft-border);
}

.section-label {
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 0.75rem;
  display: block;
}

/* ── HERO ── */
.hero {
  padding: 5rem 0 3.5rem;
}

.hero h1 {
  font-size: clamp(2.1rem, 5vw, 3rem);
  margin: 0 0 1rem;
}

.hero .subhead {
  font-size: 1.2rem;
  color: var(--muted);
  max-width: 640px;
  margin: 0 0 1.5rem;
  line-height: 1.55;
}

.hero .body {
  max-width: 640px;
  font-size: 1.02rem;
}

.hero-inner {
  display: flex;
  align-items: flex-start;
  gap: 2rem;
}

.hero-photo {
  width: 140px;
  height: 140px;
  border-radius: 50%;
  object-fit: cover;
  flex-shrink: 0;
  border: 1px solid var(--border);
}

.hero-text {
  min-width: 0;
}

@media (max-width: 640px) {
  .hero-inner {
    flex-direction: column;
  }

  .hero-photo {
    width: 110px;
    height: 110px;
  }
}

/* ── BUTTONS ── */
.btn-row {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  margin-top: 1.75rem;
}

.btn {
  display: inline-block;
  padding: 0.7rem 1.3rem;
  border-radius: 6px;
  font-size: 0.95rem;
  font-weight: 500;
  border: 1px solid var(--border);
}

.btn:hover { text-decoration: none; }

.btn-primary {
  background: var(--ink);
  color: var(--bg);
  border-color: var(--ink);
}
.btn-primary:hover { opacity: 0.85; }

.btn-secondary {
  color: var(--accent);
  border-color: var(--accent-soft-border);
}
.btn-secondary:hover {
  border-color: var(--accent);
  background: var(--accent-soft);
}

/* ── CARDS / GRID ── */
.card-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
}

@media (max-width: 720px) {
  .card-grid { grid-template-columns: 1fr; }
}

.card {
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.75rem;
  background: var(--bg-alt);
  display: flex;
  flex-direction: column;
  transition: border-color 0.15s ease;
}

.card:hover {
  border-color: var(--accent);
}

.card.featured {
  border-color: var(--accent);
  background: var(--accent-soft);
}

.card h2 {
  font-size: 1.15rem;
  margin: 0 0 0.6rem;
}

.card p {
  color: var(--muted);
  font-size: 0.95rem;
  margin: 0 0 1rem;
  flex-grow: 1;
}

.card .tags {
  margin-bottom: 1rem;
}

.tag {
  display: inline-block;
  font-size: 0.72rem;
  letter-spacing: 0.03em;
  color: var(--accent);
  border: 1px solid var(--accent-soft-border);
  background: var(--accent-soft);
  border-radius: 4px;
  padding: 0.15rem 0.5rem;
  margin: 0 0.35rem 0.35rem 0;
}

/* ── FIELD NOTES LIST ── */
.note-item {
  padding: 1.75rem 0;
  border-bottom: 1px solid var(--border);
  transition: background-color 0.15s ease;
}
.note-item:last-child { border-bottom: none; }

.note-item:not(.upcoming):hover {
  background: var(--accent-soft);
}

.note-item h2 {
  font-size: 1.2rem;
  margin: 0 0 0.4rem;
}

.note-item .note-sub {
  color: var(--muted);
  font-size: 0.95rem;
  margin: 0 0 0.6rem;
}

.note-item.upcoming {
  opacity: 0.7;
}

.pill {
  display: inline-block;
  font-size: 0.7rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 0.2rem 0.55rem;
  border-radius: 4px;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  color: var(--muted);
}

/* ── ARTICLE ── */
.article-header {
  padding: 3.5rem 0 2rem;
}

.article-header h1 {
  font-size: clamp(1.8rem, 4vw, 2.5rem);
  margin: 0 0 0.75rem;
}

.article-sub {
  color: var(--muted);
  font-size: 1.1rem;
  line-height: 1.6;
}

.article-body p,
.article-body ul,
.article-body ol {
  margin: 0 0 1.3rem;
}

.article-body h2 {
  font-size: 1.35rem;
  margin: 2.2rem 0 1rem;
}

.article-body h3 {
  font-size: 1.1rem;
  margin: 1.6rem 0 0.75rem;
}

.article-body li {
  margin-bottom: 0.5rem;
}

.callout {
  border-left: 3px solid var(--accent);
  background: var(--accent-soft);
  padding: 1rem 1.5rem;
  margin: 1.75rem 0;
  color: var(--muted);
  font-style: italic;
}

pre {
  background: var(--code-bg);
  color: var(--code-ink);
  padding: 1.1rem 1.3rem;
  border-radius: 8px;
  overflow-x: auto;
  font-size: 0.85rem;
  line-height: 1.6;
  margin: 1rem 0 1.5rem;
}

.code-label {
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 0 0 0.4rem;
}

/* ── CASE STUDY META ── */
.meta-row {
  display: flex;
  gap: 2.5rem;
  flex-wrap: wrap;
  margin: 1.5rem 0 0;
  padding: 1.5rem 0;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.meta-item .meta-label {
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted);
  display: block;
  margin-bottom: 0.25rem;
}

.meta-item .meta-value {
  font-size: 0.95rem;
}

/* ── INTERESTS ── */
.interest-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}

.interest-list .tag {
  font-size: 0.85rem;
  padding: 0.35rem 0.8rem;
}

/* ── HERO SKILLS + AVAILABILITY ── */
.hero .interest-list {
  margin: 1.5rem 0 0;
}

.availability-line {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin: 1.25rem 0 0;
  font-size: 0.92rem;
  color: var(--muted);
}

.availability-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent);
  flex-shrink: 0;
}

/* ── APPROACH LIST ── */
.approach-list {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem 1.5rem;
  list-style: none;
  margin: 1.75rem 0 0;
  padding: 0;
}

@media (max-width: 640px) {
  .approach-list { grid-template-columns: 1fr; }
}

.approach-list li {
  display: flex;
  align-items: baseline;
  gap: 0.6rem;
  font-size: 0.98rem;
}

.approach-list li::before {
  content: "→";
  color: var(--accent);
  flex-shrink: 0;
}

/* ── SKILLS GROUPS ── */
.skills-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  margin-top: 1.75rem;
}

@media (max-width: 640px) {
  .skills-grid { grid-template-columns: 1fr; }
}

.skill-group h3 {
  font-size: 0.95rem;
  margin: 0 0 0.85rem;
}

.skill-group .interest-list .tag {
  font-size: 0.8rem;
  padding: 0.3rem 0.7rem;
}

/* ── RESUME SUMMARY ── */
.resume-summary-list {
  columns: 2;
  column-gap: 2rem;
  margin: 1.5rem 0 0;
  padding: 0;
  list-style: none;
}

@media (max-width: 640px) {
  .resume-summary-list { columns: 1; }
}

.resume-summary-list li {
  break-inside: avoid;
  padding: 0.4rem 0;
  font-size: 0.98rem;
}

/* ── FOOTER ── */
footer {
  border-top: 1px solid var(--border);
  margin-top: 2rem;
}

.footer-inner {
  max-width: var(--max-wide);
  margin: 0 auto;
  padding: 2.5rem 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  color: var(--muted);
  font-size: 0.88rem;
}

.footer-links {
  display: flex;
  gap: 1.25rem;
}

/* ── UTIL ── */
.center { text-align: center; }
.mt-0 { margin-top: 0; }
.small { font-size: 0.88rem; color: var(--muted); }