/* ==========================================================================
   Malik A. Hussain — shared site styles (editorial theme)
   Adapted from Mark Koyama's site design
   ========================================================================== */

:root {
  --navy:        #1a365d;
  --navy-deep:   #102542;
  --navy-soft:   #2c5282;
  --accent:      #b08442;   /* warm gold */
  --accent-dark: #8a6630;
  --ink:         #2a2a2a;
  --muted:       #5d5d5d;
  --bg:          #faf8f4;   /* warm off-white */
  --card:        #ffffff;
  --line:        #e6e0d6;
  --line-soft:   #efeae1;
  --serif:       'Fraunces', Georgia, 'Times New Roman', serif;
  --body:        Georgia, 'Times New Roman', serif;
  --sans:        'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --shadow-sm:   0 1px 3px rgba(16, 37, 66, 0.06);
  --shadow-md:   0 8px 24px rgba(16, 37, 66, 0.10);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  font-family: var(--body);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

a       { color: var(--navy-soft); text-decoration: none; transition: color .15s ease; }
a:hover { color: var(--accent-dark); text-decoration: underline; text-underline-offset: 2px; }

/* ---------- Top navigation ------------------------------------------------ */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: saturate(160%) blur(8px);
  border-bottom: 1px solid var(--line);
}
.site-nav__inner {
  max-width: 1140px;
  margin: 0 auto;
  padding: 0 30px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 60px;
  gap: 20px;
}
.site-nav__brand {
  font-family: var(--serif);
  font-weight: 600;
  font-size: 1.25rem;
  color: var(--navy);
  letter-spacing: .2px;
  white-space: nowrap;
}
.site-nav__brand:hover { color: var(--navy); text-decoration: none; }
.site-nav__links {
  display: flex;
  align-items: center;
  gap: 26px;
  flex-wrap: wrap;
}
.site-nav__links a {
  font-family: var(--sans);
  font-size: .82rem;
  font-weight: 500;
  letter-spacing: .06em;
  text-transform: uppercase;
  color: var(--muted);
  padding: 4px 0;
  border-bottom: 2px solid transparent;
}
.site-nav__links a:hover {
  color: var(--navy);
  text-decoration: none;
  border-bottom-color: var(--accent);
}
.site-nav__links a.is-active {
  color: var(--navy);
  border-bottom-color: var(--navy);
}

/* ---------- Hero ---------------------------------------------------------- */
.hero {
  background:
    radial-gradient(1200px 400px at 80% -10%, rgba(176, 132, 66, 0.22), transparent 60%),
    linear-gradient(135deg, var(--navy) 0%, var(--navy-deep) 100%);
  color: #fff;
}
.hero__inner {
  max-width: 1140px;
  margin: 0 auto;
  padding: 56px 30px 60px;
  display: flex;
  align-items: center;
  gap: 48px;
}
.hero__photo { flex-shrink: 0; }
.hero__photo img {
  width: 190px;
  height: 190px;
  object-fit: cover;
  border-radius: 50%;
  border: 5px solid rgba(255, 255, 255, 0.16);
  box-shadow: 0 12px 36px rgba(0, 0, 0, 0.30);
}
.hero__text { min-width: 0; }
.hero__eyebrow {
  font-family: var(--sans);
  font-size: .8rem;
  font-weight: 600;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 10px;
}
.hero__title {
  font-family: var(--serif);
  font-weight: 600;
  font-size: 3.2rem;
  line-height: 1.05;
  margin: 0 0 16px;
  color: #fff;
}
.hero__lead {
  font-size: 1.12rem;
  line-height: 1.6;
  margin: 0 0 18px;
  color: rgba(255, 255, 255, 0.92);
  max-width: 640px;
}
.hero__lead a { color: #fff; text-decoration: underline; text-decoration-color: var(--accent); text-underline-offset: 3px; }
.hero__lead a:hover { color: var(--accent); }
.hero__cta {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 6px;
}
.hero__cta a {
  font-family: var(--sans);
  font-size: .85rem;
  font-weight: 600;
  letter-spacing: .04em;
  padding: 10px 20px;
  border-radius: 6px;
  border: 1px solid rgba(255, 255, 255, 0.35);
  color: #fff;
}
.hero__cta a:hover { background: var(--accent); text-decoration: none; border-color: var(--accent); color: #1c1303; }
.hero__cta a.is-primary { background: var(--accent); border-color: var(--accent); color: #1c1303; }
.hero__cta a.is-primary:hover { background: #c79552; }

/* ---------- Page layout --------------------------------------------------- */
#wrap {
  max-width: 1140px;
  margin: 0 auto;
  padding: 0 30px;
}
.page-container {
  display: flex;
  gap: 48px;
  padding: 44px 0 60px;
  align-items: flex-start;
}
.main-content { flex: 1; min-width: 0; }
.main-content.is-wide { max-width: none; }

/* Page heading (Research / Teaching) */
.page-head { padding: 40px 0 6px; }
.page-head h1 {
  font-family: var(--serif);
  font-weight: 600;
  font-size: 2.6rem;
  color: var(--navy);
  margin: 0 0 8px;
}
.page-head p {
  font-family: var(--sans);
  color: var(--muted);
  font-size: 1rem;
  margin: 0;
  max-width: 640px;
}

/* ---------- Headings ------------------------------------------------------ */
h2 { font-family: var(--serif); color: var(--navy); font-weight: 600; }
h3 {
  font-family: var(--serif);
  font-weight: 600;
  color: var(--navy);
  font-size: 1.55rem;
  margin: 46px 0 22px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--line);
  position: relative;
}
h3::before {
  content: "";
  position: absolute;
  left: 0;
  bottom: -2px;
  width: 64px;
  height: 2px;
  background: var(--accent);
}

p { margin: 0 0 1.2em; }

/* ---------- Sidebar ------------------------------------------------------- */
.sidebar {
  width: 248px;
  flex-shrink: 0;
  font-family: var(--sans);
}
.sidebar-section { margin-bottom: 26px; }
.sidebar-section h4 {
  font-family: var(--sans);
  font-size: .78rem;
  font-weight: 700;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--navy);
  margin: 0 0 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--line);
}
.sidebar-section ul { list-style: none; padding: 0; margin: 0; }
.sidebar-section li { margin-bottom: 9px; line-height: 1.4; }
.sidebar-section a { font-size: .88rem; color: var(--navy-soft); }
.sidebar-section a:hover { color: var(--accent-dark); }

/* Collapsible sidebar sections */
.collapsible-header { cursor: pointer; display: flex; justify-content: space-between; align-items: center; }
.collapsible-header:hover { color: var(--accent-dark); }
.collapsible-header::after { content: '+'; font-size: 1.1em; font-weight: 700; color: var(--accent); }
.collapsible-header.active::after { content: '\2212'; }
.collapsible-content { display: none; padding-top: 8px; }
.collapsible-content.show { display: block; }

/* ---------- Paper entries (Research) -------------------------------------- */
.paper-title { color: var(--navy); }
a .paper-title:hover, .paper-title a:hover { color: var(--accent-dark); }

.paper-abstract {
  font-family: var(--sans);
  color: var(--muted);
  font-size: .94rem;
  line-height: 1.55;
  margin-top: 6px;
}

.paper-entry {
  display: flex;
  gap: 28px;
  align-items: center;
  margin-bottom: 22px;
  padding: 22px 24px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 10px;
  box-shadow: var(--shadow-sm);
  transition: box-shadow .2s ease, transform .2s ease, border-color .2s ease;
}
.paper-entry:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
  border-color: #d8cdb8;
}
.paper-text { flex: 1; min-width: 0; }
.paper-text > p { margin-bottom: 0; }

/* expandable full abstract */
.full-abstract { margin-top: 8px; }
.full-abstract summary {
  font-family: var(--sans);
  font-size: .85rem;
  font-weight: 600;
  color: var(--navy-soft);
  cursor: pointer;
  list-style: none;
}
.full-abstract summary::-webkit-details-marker { display: none; }
.full-abstract summary::before { content: '\25B8  '; color: var(--accent); }
.full-abstract[open] summary::before { content: '\25BE  '; }
.full-abstract summary:hover { color: var(--accent-dark); }
.full-abstract p {
  font-family: var(--sans);
  font-size: .9rem;
  color: var(--muted);
  margin-top: 8px;
  line-height: 1.6;
}

/* simple list rows (full list, work in progress) */
.paper-list p {
  padding: 14px 0;
  border-bottom: 1px solid var(--line-soft);
}
.paper-list p:last-child { border-bottom: none; }

/* ---------- Course cards (Teaching) --------------------------------------- */
.course-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-left: 4px solid var(--accent);
  padding: 20px 24px;
  margin-bottom: 18px;
  border-radius: 8px;
  box-shadow: var(--shadow-sm);
  transition: box-shadow .2s ease, transform .2s ease;
}
.course-card:hover { box-shadow: var(--shadow-md); transform: translateY(-2px); }
.course-card h4 { font-family: var(--serif); margin: 0 0 4px; color: var(--navy); font-size: 1.18rem; }
.course-card h4 a { color: var(--navy); }
.course-card h4 a:hover { color: var(--accent-dark); }
.course-card .course-meta { font-family: var(--sans); color: var(--muted); font-size: .85rem; margin-bottom: 8px; }
.course-card p { margin: 0; font-size: .96rem; }

/* ---------- Buttons ------------------------------------------------------- */
.button {
  background: var(--navy-soft);
  border: none;
  color: #fff;
  padding: 10px 22px;
  font-family: var(--sans);
  font-size: .85rem;
  font-weight: 600;
  letter-spacing: .03em;
  border-radius: 6px;
  cursor: pointer;
  transition: background-color .18s ease;
}
.button:hover { background: var(--navy); }
.button3 { border-radius: 6px; }

/* ---------- Footer -------------------------------------------------------- */
.site-footer {
  border-top: 1px solid var(--line);
  background: #fff;
  margin-top: 20px;
}
.site-footer__inner {
  max-width: 1140px;
  margin: 0 auto;
  padding: 26px 30px;
  font-family: var(--sans);
  font-size: .85rem;
  color: var(--muted);
  display: flex;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

/* ---------- Responsive ---------------------------------------------------- */
@media screen and (max-width: 880px) {
  .hero__inner { flex-direction: column; text-align: center; align-items: center; gap: 28px; padding: 44px 24px 48px; }
  .hero__title { font-size: 2.5rem; }
  .hero__lead { font-size: 1.02rem; }
  .hero__cta { justify-content: center; }
  .page-container { flex-direction: column; gap: 0; }
  .sidebar { width: 100%; order: 2; margin-top: 20px; }
}
@media screen and (max-width: 720px) {
  #wrap { padding: 0 18px; }
  .site-nav__inner { padding: 0 18px; flex-wrap: wrap; min-height: 54px; }
  .site-nav__links { gap: 16px; }
  .paper-entry { flex-direction: column; align-items: flex-start; gap: 16px; padding: 18px; }
}