/* ============================================
   Henry Fan — Research Portfolio
   Academic editorial design system
   ============================================ */

@import url('https://fonts.googleapis.com/css2?family=Newsreader:ital,opsz,wght@0,6..72,300;0,6..72,400;0,6..72,500;0,6..72,600;1,6..72,400;1,6..72,500&family=DM+Sans:ital,wght@0,400;0,500;0,600;1,400&display=swap');

:root {
  --color-text: #1c1c1c;
  --color-text-secondary: #4a4a4a;
  --color-text-muted: #717171;
  --color-accent: #2c4a6e;
  --color-accent-light: #3a6b9f;
  --color-bg: #fafaf8;
  --color-bg-alt: #f2f1ed;
  --color-border: #d8d6d0;
  --color-border-light: #e8e6e2;
  --color-white: #ffffff;
  --font-serif: 'Newsreader', 'Georgia', serif;
  --font-sans: 'DM Sans', 'Helvetica Neue', sans-serif;
  --max-width: 720px;
  --max-width-wide: 960px;
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2.5rem;
  --space-2xl: 4rem;
  --space-3xl: 6rem;
}

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

html {
  font-size: 17px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-serif);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ---- Navigation ---- */

.site-nav {
  font-family: var(--font-sans);
  border-bottom: 1px solid var(--color-border);
  background: var(--color-bg);
  position: sticky;
  top: 0;
  z-index: 100;
}

.site-nav .nav-inner {
  max-width: var(--max-width-wide);
  margin: 0 auto;
  padding: 0.85rem 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.site-nav .nav-name {
  font-weight: 600;
  font-size: 0.9rem;
  letter-spacing: 0.02em;
  color: var(--color-text);
  text-decoration: none;
}

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

.site-nav .nav-links a {
  font-size: 0.82rem;
  color: var(--color-text-secondary);
  text-decoration: none;
  letter-spacing: 0.01em;
  transition: color 0.15s;
}

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

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.25rem;
  color: var(--color-text);
  font-size: 1.4rem;
  line-height: 1;
}

@media (max-width: 640px) {
  .nav-toggle {
    display: block;
  }
  .site-nav .nav-links {
    display: none;
    width: 100%;
    flex-direction: column;
    gap: 0.75rem;
    padding-top: 0.75rem;
    border-top: 1px solid var(--color-border-light);
  }
  .site-nav .nav-links.open {
    display: flex;
  }
}

/* ---- Layout ---- */

.page-container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--space-2xl) 1.5rem var(--space-3xl);
}

.page-container.wide {
  max-width: var(--max-width-wide);
}

/* ---- Typography ---- */

h1 {
  font-family: var(--font-serif);
  font-size: 2.2rem;
  font-weight: 500;
  line-height: 1.2;
  margin-bottom: var(--space-lg);
  letter-spacing: -0.01em;
}

h2 {
  font-family: var(--font-serif);
  font-size: 1.45rem;
  font-weight: 500;
  line-height: 1.3;
  margin-top: var(--space-2xl);
  margin-bottom: var(--space-md);
  color: var(--color-text);
}

h3 {
  font-family: var(--font-sans);
  font-size: 0.95rem;
  font-weight: 600;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-top: var(--space-xl);
  margin-bottom: var(--space-sm);
}

p {
  margin-bottom: var(--space-md);
}

a {
  color: var(--color-accent);
  text-decoration-thickness: 1px;
  text-underline-offset: 2px;
}

a:hover {
  color: var(--color-accent-light);
}

blockquote {
  border-left: 2px solid var(--color-accent);
  padding-left: var(--space-lg);
  margin: var(--space-xl) 0;
  font-style: italic;
  color: var(--color-text-secondary);
}

strong {
  font-weight: 600;
}

em {
  font-style: italic;
}

hr {
  border: none;
  border-top: 1px solid var(--color-border);
  margin: var(--space-2xl) 0;
}

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

.page-header {
  margin-bottom: var(--space-2xl);
}

.page-header .label {
  font-family: var(--font-sans);
  font-size: 0.78rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: var(--space-sm);
}

.page-header h1 {
  margin-bottom: var(--space-sm);
}

.page-header .subtitle {
  font-size: 1.05rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

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

.hero {
  padding: var(--space-3xl) 1.5rem;
  max-width: var(--max-width);
  margin: 0 auto;
}

.hero-label {
  font-family: var(--font-sans);
  font-size: 0.78rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: var(--space-lg);
}

.hero h1 {
  font-size: 2.6rem;
  font-weight: 400;
  line-height: 1.25;
  margin-bottom: var(--space-xl);
  max-width: 600px;
}

.hero .lead {
  font-size: 1.1rem;
  line-height: 1.75;
  color: var(--color-text-secondary);
  margin-bottom: var(--space-lg);
}

.hero .meta-info {
  font-family: var(--font-sans);
  font-size: 0.82rem;
  color: var(--color-text-muted);
  line-height: 1.8;
}

.hero .meta-info span {
  display: inline-block;
  margin-right: var(--space-lg);
}

/* ---- Cards ---- */

.card {
  background: var(--color-white);
  border: 1px solid var(--color-border);
  padding: var(--space-xl);
  margin-bottom: var(--space-lg);
  transition: border-color 0.15s;
}

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

.card .card-label {
  font-family: var(--font-sans);
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: var(--space-sm);
}

.card .card-title {
  font-family: var(--font-serif);
  font-size: 1.2rem;
  font-weight: 500;
  margin-bottom: var(--space-sm);
  color: var(--color-text);
  text-transform: none;
  letter-spacing: normal;
}

.card .card-desc {
  font-size: 0.95rem;
  color: var(--color-text-secondary);
  line-height: 1.65;
}

.card a {
  text-decoration: none;
  color: inherit;
}

/* ---- Status badges ---- */

.status {
  font-family: var(--font-sans);
  font-size: 0.7rem;
  font-weight: 500;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  padding: 0.15rem 0.5rem;
  display: inline-block;
  margin-bottom: var(--space-sm);
}

.status.proposed {
  color: var(--color-accent);
  background: #e8eef5;
}

.status.in-progress {
  color: #5a6e3a;
  background: #eef3e5;
}

.status.submitted {
  color: #7a5a2e;
  background: #f5f0e5;
}

/* ---- Research question blocks ---- */

.rq-block {
  border-left: 2px solid var(--color-border);
  padding: var(--space-lg) 0 var(--space-lg) var(--space-xl);
  margin-bottom: var(--space-xl);
}

.rq-block .rq-id {
  font-family: var(--font-sans);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--space-xs);
}

.rq-block .rq-title {
  font-family: var(--font-serif);
  font-size: 1.15rem;
  font-weight: 500;
  margin-bottom: var(--space-sm);
  color: var(--color-text);
}

.rq-block .rq-text {
  font-size: 0.95rem;
  color: var(--color-text-secondary);
  line-height: 1.65;
}

.rq-block .rq-methods {
  font-family: var(--font-sans);
  font-size: 0.8rem;
  color: var(--color-text-muted);
  margin-top: var(--space-sm);
}

/* ---- Detail sections (project pages, etc.) ---- */

.detail-section {
  margin-top: var(--space-xl);
}

.detail-section h3 {
  margin-top: 0;
}

.detail-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-md) var(--space-xl);
  margin-top: var(--space-md);
}

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

.detail-grid dt {
  font-family: var(--font-sans);
  font-size: 0.78rem;
  font-weight: 500;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: 0.15rem;
}

.detail-grid dd {
  font-size: 0.92rem;
  color: var(--color-text-secondary);
  line-height: 1.55;
}

/* ---- Timeline / Roadmap ---- */

.timeline-item {
  padding-left: var(--space-xl);
  border-left: 1px solid var(--color-border);
  padding-bottom: var(--space-xl);
  position: relative;
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: -4px;
  top: 0.4rem;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--color-accent);
}

.timeline-item:last-child {
  border-left: none;
}

.timeline-item .timeline-date {
  font-family: var(--font-sans);
  font-size: 0.78rem;
  font-weight: 500;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--space-xs);
}

.timeline-item .timeline-title {
  font-family: var(--font-serif);
  font-size: 1.05rem;
  font-weight: 500;
  margin-bottom: var(--space-xs);
  text-transform: none;
  letter-spacing: normal;
}

.timeline-item .timeline-desc {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* ---- Writing / Reading list items ---- */

.writing-item {
  padding: var(--space-lg) 0;
  border-bottom: 1px solid var(--color-border-light);
}

.writing-item:first-child {
  padding-top: 0;
}

.writing-item .writing-type {
  font-family: var(--font-sans);
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: var(--space-xs);
}

.writing-item .writing-title {
  font-size: 1.05rem;
  font-weight: 500;
  margin-bottom: var(--space-xs);
}

.writing-item .writing-desc {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* ---- About / Background section ---- */

.role-list {
  list-style: none;
  margin-top: var(--space-md);
}

.role-list li {
  padding: var(--space-md) 0;
  border-bottom: 1px solid var(--color-border-light);
  font-size: 0.95rem;
}

.role-list li:last-child {
  border-bottom: none;
}

.role-list .role-title {
  font-weight: 500;
  color: var(--color-text);
}

.role-list .role-context {
  color: var(--color-text-secondary);
  font-size: 0.9rem;
  margin-top: 0.15rem;
}

/* ---- Contact / Footer ---- */

.site-footer {
  border-top: 1px solid var(--color-border);
  padding: var(--space-xl) 1.5rem;
  font-family: var(--font-sans);
  font-size: 0.78rem;
  color: var(--color-text-muted);
  text-align: center;
}

.contact-block {
  font-family: var(--font-sans);
  font-size: 0.88rem;
  line-height: 1.8;
  margin-top: var(--space-xl);
  padding: var(--space-xl);
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border-light);
}

.contact-block a {
  color: var(--color-accent);
}

/* ---- Expandable sections ---- */

details {
  margin-top: var(--space-md);
}

details summary {
  font-family: var(--font-sans);
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--color-accent);
  cursor: pointer;
  list-style: none;
}

details summary::-webkit-details-marker {
  display: none;
}

details summary::before {
  content: '+ ';
}

details[open] summary::before {
  content: '− ';
}

details .detail-content {
  padding-top: var(--space-md);
  font-size: 0.92rem;
  color: var(--color-text-secondary);
  line-height: 1.65;
}

/* ---- Utility ---- */

.text-muted {
  color: var(--color-text-muted);
}

.text-small {
  font-size: 0.85rem;
}

.font-sans {
  font-family: var(--font-sans);
}

.mt-0 { margin-top: 0; }
.mt-sm { margin-top: var(--space-sm); }
.mt-md { margin-top: var(--space-md); }
.mt-lg { margin-top: var(--space-lg); }
.mt-xl { margin-top: var(--space-xl); }
.mt-2xl { margin-top: var(--space-2xl); }
.mb-0 { margin-bottom: 0; }
.mb-sm { margin-bottom: var(--space-sm); }
.mb-md { margin-bottom: var(--space-md); }

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
}

/* ---- Print ---- */

@media print {
  .site-nav, .nav-toggle { display: none; }
  body { font-size: 11pt; }
  .page-container { max-width: none; padding: 0; }
}