/* ================================
   Static Portfolio — Base Styles
   Keep colors here so the theme can
   be changed easily later.
   ================================ */

:root {
  --background: #ffffff;
  --surface: #f7f7f7;
  --text: #171717;
  --muted: #666666;
  --border: #dddddd;
  --accent: #171717;
  --max-width: 1120px;
  --radius: 10px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--background);
  color: var(--text);
  font-family: Arial, Helvetica, sans-serif;
  line-height: 1.6;
}

a {
  color: inherit;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.96);
  border-bottom: 1px solid var(--border);
}

.navbar {
  max-width: var(--max-width);
  min-height: 64px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  font-weight: 700;
  text-decoration: none;
  white-space: nowrap;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 24px;
}

.nav-links a {
  text-decoration: none;
  color: var(--muted);
  font-size: 0.95rem;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--text);
}

.menu-toggle {
  display: none;
  border: 0;
  background: transparent;
  font-size: 1.4rem;
  cursor: pointer;
}

.container {
  width: min(calc(100% - 48px), var(--max-width));
  margin: 0 auto;
}

.hero {
  min-height: calc(100vh - 64px);
  padding: 80px 0;
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  align-items: center;
  gap: 72px;
}

.hero h1 {
  margin: 0 0 8px;
  font-size: clamp(2.8rem, 7vw, 5.5rem);
  line-height: 1;
  letter-spacing: -0.05em;
}

.lead {
  margin: 0 0 36px;
  color: var(--muted);
  font-size: 1.2rem;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--muted);
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.info-block {
  margin: 24px 0;
}

.info-block h2 {
  margin: 0 0 6px;
  font-size: 1rem;
}

.info-block p {
  margin: 3px 0;
  color: var(--muted);
}

.hero-photo {
  display: flex;
  justify-content: center;
}

.photo-placeholder,
.image-placeholder {
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  color: #888;
  background: var(--surface);
  border: 1px dashed #bdbdbd;
  font-size: 0.85rem;
  letter-spacing: 0.08em;
}

.photo-placeholder {
  width: min(100%, 400px);
  aspect-ratio: 1 / 1;
}

.hero-photo img {
  width: min(100%, 400px);
  aspect-ratio: 1 / 1;
  object-fit: cover;
  border-radius: var(--radius);
}

.social-links {
  display: flex;
  gap: 10px;
  margin-top: 32px;
}

.social-links a {
  text-decoration: none;
}

.social-icon {
  width: 42px;
  height: 42px;
  border: 1px solid var(--border);
  border-radius: 50%;
  display: grid;
  place-items: center;
  font-weight: 700;
  font-size: 0.9rem;
}

.quick-links {
  padding-bottom: 80px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.card,
.contact-card,
.skill-card {
  padding: 28px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  text-decoration: none;
}

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

.card h2,
.contact-card h2,
.skill-card h2 {
  margin-top: 0;
}

.card p,
.contact-card p {
  margin-bottom: 0;
  color: var(--muted);
}

.page {
  padding-top: 80px;
  padding-bottom: 100px;
}

.page-heading {
  max-width: 720px;
  margin-bottom: 56px;
}

.page-heading h1 {
  margin: 0 0 12px;
  font-size: clamp(2.5rem, 6vw, 4.5rem);
  line-height: 1;
  letter-spacing: -0.04em;
}

.page-heading > p:last-child {
  margin: 0;
  color: var(--muted);
}

.project-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.project-card {
  overflow: hidden;
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.project-card .image-placeholder {
  aspect-ratio: 16 / 10;
}

.project-body {
  padding: 28px;
}

.project-number {
  margin: 0 0 8px;
  color: var(--muted);
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.08em;
}

.project-body h2,
.research-item h2 {
  margin-top: 0;
}

.project-body p:not(.project-number),
.research-item > div:last-child > p {
  color: var(--muted);
}

.project-body ul,
.research-item ul,
.timeline-content ul,
.skill-card ul {
  padding-left: 20px;
}

.text-link {
  display: inline-block;
  margin-top: 12px;
  font-weight: 700;
  text-decoration: none;
}

.research-list {
  display: grid;
  gap: 56px;
}

.research-item {
  display: grid;
  grid-template-columns: 0.8fr 1.2fr;
  gap: 48px;
  align-items: start;
}

.research-image {
  aspect-ratio: 16 / 10;
  border-radius: var(--radius);
}

.timeline {
  border-left: 1px solid var(--border);
}

.timeline-item {
  position: relative;
  display: grid;
  grid-template-columns: 120px 1fr;
  gap: 32px;
  padding: 0 0 56px 40px;
}

.timeline-item::before {
  content: "";
  position: absolute;
  left: -5px;
  top: 6px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--accent);
}

.timeline-year {
  font-weight: 700;
}

.timeline-content h2 {
  margin: 0 0 8px;
}

.timeline-content p {
  color: var(--muted);
}

.skills-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.skill-card li {
  margin: 6px 0;
}

.contact-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.contact-card a {
  color: var(--text);
}

.site-footer {
  padding: 32px 24px;
  border-top: 1px solid var(--border);
  text-align: center;
  color: var(--muted);
  font-size: 0.9rem;
}

@media (max-width: 800px) {
  .menu-toggle {
    display: block;
  }

  .nav-links {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    padding: 16px 24px 24px;
    background: var(--background);
    border-bottom: 1px solid var(--border);
    flex-direction: column;
    align-items: flex-start;
  }

  .nav-links.open {
    display: flex;
  }

  .hero {
    grid-template-columns: 1fr;
    padding: 56px 0;
    gap: 48px;
  }

  .hero-photo {
    order: -1;
  }

  .quick-links,
  .project-grid,
  .skills-grid,
  .contact-grid {
    grid-template-columns: 1fr;
  }

  .research-item {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .timeline-item {
    grid-template-columns: 1fr;
    gap: 4px;
    padding-left: 28px;
  }
}