/* ==========================================================================
   Custom styles — Kyungho Lee
   ========================================================================== */

/* ── Base palette ─────────────────────────────────────────── */
:root {
  --yale-blue:   #0F4D92;
  --yale-dark:   #0a3561;
  --yale-light:  #e8eff8;
  --yale-accent: #1a6bc4;
  --warm-bg:     #fafaf8;
  --warm-bg-alt: #f5f4f1;
  --text-primary:#1a1a1a;
  --text-secondary:#555;
  --text-muted:  #888;
  --border-light:#e5e2dd;
  --border-subtle:#eeebe6;
}

/* ── Typography ───────────────────────────────────────────── */
body {
  font-family: 'Noto Serif', Georgia, serif;
  background-color: var(--warm-bg);
  color: var(--text-primary);
}

h1, h2, h3, h4, h5, h6 {
  font-family: 'Noto Serif', Georgia, serif;
  font-weight: 700;
}

p, li, dd, dt, blockquote {
  font-family: 'Noto Serif', Georgia, serif;
  font-weight: 400;
}

/* ── Accent top-border ────────────────────────────────────── */
body::before {
  content: '';
  display: block;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--yale-blue), var(--yale-accent), var(--yale-blue));
  z-index: 9999;
}

/* ── Wrapper / canvas warm background ─────────────────────── */
.wrapper {
  background-color: var(--warm-bg) !important;
}

.sidebar {
  background-color: var(--warm-bg-alt);
  border-right: 1px solid var(--border-subtle);
}

/* ── Links — cohesive Yale blue ───────────────────────────── */
a,
a:visited {
  color: var(--yale-blue) !important;
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover,
a:focus,
a:active {
  color: var(--yale-dark) !important;
}

/* ── Buttons ──────────────────────────────────────────────── */
a.btn {
  color: #fff !important;
  background-color: var(--yale-blue) !important;
  border: 1px solid var(--yale-blue) !important;
  border-radius: 4px;
  padding: 0.5em 1.25em;
  font-family: 'Source Sans 3', Helvetica, sans-serif;
  font-size: 0.85em;
  font-weight: 500;
  letter-spacing: 0.3px;
  transition: background-color 0.2s ease, box-shadow 0.2s ease;
}

a.btn:hover {
  background-color: var(--yale-dark) !important;
  box-shadow: 0 2px 8px rgba(15, 77, 146, 0.2);
}

/* ── Intro / Home ─────────────────────────────────────────── */
h1.intro-title {
  margin-bottom: 1rem;
  color: var(--text-primary);
  line-height: 1;
}

.intro-text {
  color: var(--text-secondary);
}

/* ── Section headings ─────────────────────────────────────── */
h2 {
  color: var(--text-primary);
  padding-bottom: 0.3em;
  border-bottom: 1px solid var(--border-light);
  margin-bottom: 1rem;
}

h3 {
  color: var(--text-primary);
  margin-bottom: 0.3rem;
}

/* ── Page content — refined spacing ───────────────────────── */
.page-content {
  line-height: 1.75;
}

.entry-content {
  line-height: 1.75;
}

/* ── Site title ───────────────────────────────────────────── */
.site-title a {
  color: var(--text-primary) !important;
  letter-spacing: -0.3px;
}

/* ── Navigation ───────────────────────────────────────────── */
.site-nav .menu-item a {
  font-family: 'Source Sans 3', Helvetica, sans-serif;
  font-weight: 700;
  font-size: 0.95em;
  color: var(--text-secondary) !important;
  transition: color 0.2s ease;
}

.site-nav .menu-item a:hover {
  color: var(--yale-blue) !important;
}

/* ── Contact list in sidebar ──────────────────────────────── */
.contact-list a {
  font-family: 'Source Sans 3', Helvetica, sans-serif;
  font-size: 0.9em;
}

/* ── Footer ───────────────────────────────────────────────── */
.site-footer {
  border-top: 1px solid var(--border-light);
  color: var(--text-muted);
  font-size: 0.85em;
}

/* ── Research page ────────────────────────────────────────── */

.research-page h1 {
  font-family: 'Noto Serif', Georgia, serif;
  font-size: 28px;
  font-weight: 600;
  letter-spacing: -0.3px;
  margin-bottom: 2px;
  border-bottom: none;
}

.research-page .page-subtitle {
  font-size: 13px;
  color: var(--text-muted);
  font-weight: 400;
  margin-bottom: 1.5rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border-light);
}

.research-page h2 {
  font-family: 'Source Sans 3', Helvetica, sans-serif;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 1.2px;
  text-transform: uppercase;
  color: var(--yale-blue);
  margin-top: 2.5rem;
  margin-bottom: 1.25rem;
  padding-bottom: 0;
  border-bottom: none;
}

.research-page hr {
  border: none;
  border-top: 1px solid var(--border-light);
  margin: 2.5rem 0 0;
}

.research-page .paper {
  margin-bottom: 2.5rem;
  padding-left: 1rem;
  border-left: 2px solid var(--border-subtle);
  transition: border-color 0.2s ease;
}

.research-page .paper:hover {
  border-left-color: var(--yale-blue);
}

.research-page .paper-title {
  font-family: 'Noto Serif', Georgia, serif;
  font-size: 17px;
  font-weight: 600;
  line-height: 1.4;
  margin-bottom: 2px;
}

.research-page .paper-title a {
  color: inherit !important;
  text-decoration: none;
}

.research-page .paper-title a:hover {
  color: var(--yale-blue) !important;
  text-decoration: none;
}

.research-page .paper-authors {
  font-family: 'Source Sans 3', Helvetica, sans-serif;
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 6px;
}

.research-page .paper-desc {
  font-size: 13.5px;
  color: var(--text-secondary);
  line-height: 1.55;
  margin-bottom: 8px;
  font-style: italic;
}

.research-page .paper-links {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 6px;
}

.research-page .paper-links a,
.research-page .paper-links a:visited {
  display: inline-block;
  font-family: 'Source Sans 3', Helvetica, sans-serif;
  font-size: 12px;
  font-weight: 500;
  padding: 3px 10px;
  border-radius: 4px;
  border: 1px solid var(--border-light);
  color: var(--text-secondary) !important;
  text-decoration: none !important;
  background: var(--warm-bg-alt);
  transition: border-color 0.15s, color 0.15s, background 0.15s;
}

.research-page .paper-links a:hover {
  border-color: var(--yale-blue);
  color: var(--yale-blue) !important;
  background: var(--yale-light);
}

.research-page .paper-venue {
  font-family: 'Source Sans 3', Helvetica, sans-serif;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-primary);
  margin-bottom: 2px;
}

.research-page .paper-venue em {
  font-style: italic;
}

.research-page .paper-presentations {
  font-family: 'Source Sans 3', Helvetica, sans-serif;
  font-size: 12.5px;
  color: var(--text-muted);
  line-height: 1.5;
  margin-top: 4px;
}

.research-page .paper-presentations em {
  font-style: normal;
  font-weight: 500;
  color: var(--text-secondary);
}

.research-page .award {
  display: inline-block;
  font-family: 'Source Sans 3', Helvetica, sans-serif;
  font-size: 12px;
  font-weight: 500;
  color: #85600b;
  background: #fdf3e0;
  padding: 3px 10px;
  border-radius: 4px;
  margin-top: 6px;
  margin-right: 6px;
}