:root {
  --bg: #0a121c;
  --bg-elevated: #0f1b29;
  --ink: #e9e4d8;
  --ink-dim: #8296a6;
  --ink-faint: #4d6072;
  --accent: #ffb454;
  --accent-2: #6fd8c7;
  --rule: rgba(143, 163, 179, 0.16);
  --rule-strong: rgba(143, 163, 179, 0.32);
  --display: "Space Mono", monospace;
  --body: "IBM Plex Sans", sans-serif;
  --mono: "IBM Plex Mono", monospace;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  background: var(--bg);
  color: var(--ink);
  font-family: var(--body);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* faint blueprint grid */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(var(--rule) 1px, transparent 1px),
    linear-gradient(90deg, var(--rule) 1px, transparent 1px);
  background-size: 48px 48px;
  opacity: 0.35;
  pointer-events: none;
  z-index: 0;
}

a {
  color: var(--accent-2);
  text-decoration: none;
}
a:hover {
  text-decoration: underline;
}
a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

.wrap {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 84px 1fr;
  max-width: 1180px;
  margin: 0 auto;
}

/* ---------- Memory-map rail ---------- */
.rail {
  position: sticky;
  top: 0;
  height: 100vh;
  border-right: 1px solid var(--rule);
  padding-top: 48px;
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 0;
}
.rail-addr {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--ink-faint);
  padding-right: 14px;
  letter-spacing: 0.02em;
  writing-mode: vertical-rl;
  text-orientation: mixed;
  height: var(--h, 220px);
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 10px;
  border-bottom: 1px solid var(--rule);
  transition: color 0.3s ease;
  position: relative;
}
.rail-addr::before {
  content: "";
  position: absolute;
  right: -1px;
  top: 0;
  width: 3px;
  height: 100%;
  background: transparent;
  transition: background 0.3s ease;
}
.rail-addr.active {
  color: var(--accent);
}
.rail-addr.active::before {
  background: var(--accent);
}
.rail-seg {
  text-transform: uppercase;
}

@media (max-width: 760px) {
  .wrap {
    grid-template-columns: 1fr;
  }
  .rail {
    display: none;
  }
}

/* ---------- Sections ---------- */
main {
  min-width: 0;
}

section {
  padding: 96px 40px;
  border-bottom: 1px solid var(--rule);
  opacity: 0;
  transform: translateY(14px);
  transition:
    opacity 0.6s ease,
    transform 0.6s ease;
}
section.in-view {
  opacity: 1;
  transform: translateY(0);
}
@media (prefers-reduced-motion: reduce) {
  section {
    opacity: 1;
    transform: none;
    transition: none;
  }
}
@media (max-width: 760px) {
  section {
    padding: 64px 22px;
  }
}

.eyebrow {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--ink-faint);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin-bottom: 14px;
  display: flex;
  align-items: center;
  gap: 10px;
}
.eyebrow::before {
  content: "";
  width: 18px;
  height: 1px;
  background: var(--ink-faint);
}

h1,
h2,
h3 {
  font-family: var(--display);
  font-weight: 700;
}
h2 {
  font-size: clamp(1.5rem, 3vw, 2.1rem);
  color: var(--ink);
  margin-bottom: 28px;
  letter-spacing: -0.01em;
}

/* ---------- Hero ---------- */
#hero {
  padding-top: 120px;
  padding-bottom: 100px;
  border-bottom: 1px solid var(--rule);
}
.boot-line {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--accent-2);
  margin-bottom: 26px;
  opacity: 0.85;
}
.boot-line .cursor {
  display: inline-block;
  width: 7px;
  height: 13px;
  background: var(--accent-2);
  margin-left: 4px;
  animation: blink 1.1s step-end infinite;
  vertical-align: -2px;
}
@keyframes blink {
  50% {
    opacity: 0;
  }
}
@media (prefers-reduced-motion: reduce) {
  .boot-line .cursor {
    animation: none;
  }
}

h1 {
  font-size: clamp(2.1rem, 5.4vw, 3.6rem);
  line-height: 1.12;
  letter-spacing: -0.015em;
  max-width: 15ch;
}
h1 .hl {
  color: var(--accent);
}

.tagline {
  margin-top: 22px;
  max-width: 56ch;
  font-size: 1.05rem;
  color: var(--ink-dim);
}

.hero-links {
  margin-top: 38px;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}
.btn {
  font-family: var(--mono);
  font-size: 13px;
  padding: 10px 16px;
  border: 1px solid var(--rule-strong);
  border-radius: 3px;
  color: var(--ink);
  transition:
    border-color 0.2s ease,
    color 0.2s ease,
    background 0.2s ease;
}
.btn:hover {
  border-color: var(--accent);
  color: var(--accent);
  text-decoration: none;
  background: rgba(255, 180, 84, 0.06);
}
.btn.primary {
  border-color: var(--accent-2);
  color: var(--accent-2);
}
.btn.primary:hover {
  background: rgba(111, 216, 199, 0.08);
  border-color: var(--accent-2);
  color: var(--accent-2);
}

/* ---------- About ---------- */
#about p {
  max-width: 64ch;
  color: var(--ink-dim);
  font-size: 1.02rem;
}
#about p + p {
  margin-top: 16px;
}
#about strong {
  color: var(--ink);
  font-weight: 600;
}

/* ---------- Project cards ---------- */
.card-grid {
  display: grid;
  gap: 20px;
  grid-template-columns: 1fr;
}
.card {
  border: 1px solid var(--rule);
  border-radius: 4px;
  padding: 26px 28px;
  background: var(--bg-elevated);
  position: relative;
  transition:
    border-color 0.2s ease,
    transform 0.2s ease;
}
.card:hover {
  border-color: var(--rule-strong);
  transform: translateY(-2px);
}
.card.placeholder {
  border-style: dashed;
  opacity: 0.55;
}
.card-addr {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--ink-faint);
  letter-spacing: 0.04em;
  margin-bottom: 10px;
}
.card h3 {
  font-family: var(--body);
  font-weight: 600;
  font-size: 1.12rem;
  color: var(--ink);
  margin-bottom: 10px;
  letter-spacing: 0;
}
.card p {
  color: var(--ink-dim);
  font-size: 0.96rem;
  max-width: 64ch;
}
.tag-row {
  margin-top: 16px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.tag {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--accent-2);
  border: 1px solid rgba(111, 216, 199, 0.28);
  border-radius: 3px;
  padding: 3px 8px;
}
.card-link {
  display: inline-block;
  margin-top: 18px;
  font-family: var(--mono);
  font-size: 12.5px;
}

/* ---------- Research ---------- */
.research-block {
  display: grid;
  gap: 28px;
  grid-template-columns: repeat(3, 1fr);
  margin-top: 8px;
}
@media (max-width: 900px) {
  .research-block {
    grid-template-columns: 1fr;
  }
}
.research-item .k {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 10px;
  display: block;
}
.research-item p {
  color: var(--ink-dim);
  font-size: 0.95rem;
}
#research > p {
  max-width: 68ch;
  color: var(--ink-dim);
  margin-bottom: 36px;
}

/* ---------- Footer / contact ---------- */
#contact {
  border-bottom: none;
  padding-bottom: 80px;
}
.contact-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 10px;
}
footer.meta {
  margin-top: 60px;
  font-family: var(--mono);
  font-size: 11px;
  color: var(--ink-faint);
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px;
}