/* ============================================
   Academic Profile — Refined Design System
   ============================================ */

@import url('https://fonts.googleapis.com/css2?family=DM+Serif+Display:ital@0;1&family=Outfit:wght@300;400;500;600;700&display=swap');

:root {
  /* Sidebar & dark surfaces */
  --sidebar-bg:       #0f1b2d;
  --sidebar-bg-light: #162236;
  --sidebar-text:     #c8d0dc;
  --sidebar-heading:  #ffffff;

  /* Accent — warm amber-gold */
  --accent:           #d4a054;
  --accent-hover:     #e2b36a;
  --accent-glow:      rgba(212, 160, 84, 0.15);
  --accent-subtle:    rgba(212, 160, 84, 0.08);

  /* Main content surfaces */
  --bg:               #f5f3ef;
  --bg-card:          #ffffff;
  --bg-card-hover:    #fffdf9;

  /* Ink */
  --ink:              #1c2333;
  --ink-secondary:    #4a5068;
  --ink-muted:        #8890a4;
  --ink-faint:        #b8bcc8;

  --border:           #e2dfd8;
  --border-light:     #ece9e3;
  --shadow-sm:        0 1px 3px rgba(15,27,45,0.05), 0 1px 2px rgba(15,27,45,0.03);
  --shadow-md:        0 4px 12px rgba(15,27,45,0.07), 0 1px 4px rgba(15,27,45,0.04);
  --shadow-lg:        0 8px 30px rgba(15,27,45,0.10), 0 2px 8px rgba(15,27,45,0.05);

  --font-display: 'DM Serif Display', Georgia, serif;
  --font-body:    'Outfit', 'Helvetica Neue', Arial, sans-serif;

  --sidebar-w:    280px;
  --radius:       8px;
  --transition:   0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

/* --- Reset --- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; scroll-behavior: smooth; }
body {
  font-family: var(--font-body);
  font-weight: 400;
  line-height: 1.72;
  color: var(--ink);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }
a { color: var(--accent); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--accent-hover); }

/* =========================================
   SIDEBAR
   ========================================= */
.sidebar {
  position: fixed; top: 0; left: 0;
  width: var(--sidebar-w);
  height: 100vh;
  background: var(--sidebar-bg);
  display: flex; flex-direction: column;
  z-index: 100;
  overflow-y: auto;
}

/* Decorative top accent line */
.sidebar::before {
  content: '';
  position: absolute; top: 0; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--accent), var(--accent-hover), var(--accent));
}

.sidebar__header {
  padding: 2.5rem 1.8rem 1.5rem;
  text-align: center;
  border-bottom: 1px solid rgba(255,255,255,0.06);
}

.sidebar__photo {
  width: 130px; height: 130px;
  border-radius: 50%;
  object-fit: cover;
  margin: 0 auto 1.2rem;
  border: 3px solid rgba(212,160,84,0.3);
  box-shadow: 0 4px 20px rgba(0,0,0,0.3);
}
.sidebar__photo-placeholder {
  width: 130px; height: 130px;
  border-radius: 50%;
  margin: 0 auto 1.2rem;
  background: var(--sidebar-bg-light);
  border: 3px solid rgba(212,160,84,0.3);
  display: flex; align-items: center; justify-content: center;
  color: var(--sidebar-text);
  font-size: 0.72rem;
  text-align: center;
}

.sidebar__name {
  font-family: var(--font-display);
  font-size: 1.35rem;
  color: var(--sidebar-heading);
  margin-bottom: 0.3rem;
  letter-spacing: 0.01em;
}
.sidebar__title {
  font-size: 0.78rem;
  font-weight: 400;
  color: var(--sidebar-text);
  line-height: 1.5;
  letter-spacing: 0.02em;
}

/* Navigation */
.sidebar__nav {
  padding: 1.5rem 0;
  flex: 1;
}
.sidebar__nav ul { list-style: none; }
.sidebar__nav li { position: relative; }
.sidebar__nav a {
  display: flex; align-items: center; gap: 0.8rem;
  padding: 0.75rem 1.8rem;
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--sidebar-text);
  letter-spacing: 0.03em;
  transition: all var(--transition);
  border-left: 3px solid transparent;
}
.sidebar__nav a:hover {
  color: var(--sidebar-heading);
  background: rgba(255,255,255,0.04);
  border-left-color: rgba(212,160,84,0.3);
}
.sidebar__nav a.active {
  color: var(--accent);
  background: rgba(212,160,84,0.06);
  border-left-color: var(--accent);
  font-weight: 600;
}
.sidebar__nav .nav-icon {
  width: 18px; height: 18px;
  opacity: 0.7;
  flex-shrink: 0;
}

/* Contact block at bottom */
.sidebar__contact {
  padding: 1.5rem 1.8rem;
  border-top: 1px solid rgba(255,255,255,0.06);
  font-size: 0.8rem;
  color: var(--sidebar-text);
}
.sidebar__contact a {
  color: var(--sidebar-text);
  display: flex; align-items: center; gap: 0.6rem;
  padding: 0.4rem 0;
  transition: color var(--transition);
}
.sidebar__contact a:hover { color: var(--accent); }

/* =========================================
   MAIN CONTENT
   ========================================= */
.main {
  margin-left: var(--sidebar-w);
  min-height: 100vh;
}

.content {
  max-width: 780px;
  margin: 0 auto;
  padding: 3rem 3rem 4rem;
}

/* --- Page Hero (Home) --- */
.page-hero {
  padding: 3.5rem 0 2rem;
}
.page-hero h1 {
  font-family: var(--font-display);
  font-size: 2.6rem;
  font-weight: 400;
  line-height: 1.2;
  margin-bottom: 0.4rem;
  color: var(--ink);
}
.page-hero .lead {
  font-size: 1.1rem;
  color: var(--ink-secondary);
  font-weight: 300;
  line-height: 1.7;
  margin-bottom: 1.5rem;
}
.page-hero__divider {
  width: 50px; height: 3px;
  background: var(--accent);
  border: none;
  margin: 0 0 2rem;
  border-radius: 2px;
}

/* --- Page Header (inner pages) --- */
.page-header {
  padding: 3rem 0 1.5rem;
  margin-bottom: 2rem;
}
.page-header h1 {
  font-family: var(--font-display);
  font-size: 2.2rem;
  font-weight: 400;
  color: var(--ink);
}
.page-header__divider {
  width: 40px; height: 3px;
  background: var(--accent);
  border: none;
  margin: 0.8rem 0 0;
  border-radius: 2px;
}

/* --- Section --- */
.section {
  margin-bottom: 3rem;
}
.section__label {
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 1.2rem;
}
.section__title {
  font-family: var(--font-display);
  font-size: 1.45rem;
  font-weight: 400;
  margin-bottom: 1.5rem;
  color: var(--ink);
}

/* --- Interest Tags --- */
.tags {
  display: flex; flex-wrap: wrap; gap: 0.6rem;
  margin-bottom: 1rem;
}
.tag {
  display: inline-block;
  padding: 0.4rem 1rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 50px;
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--ink-secondary);
  transition: all var(--transition);
}
.tag:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-subtle);
}

/* --- Paper Cards --- */
.paper-card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius);
  padding: 1.8rem 2rem;
  margin-bottom: 1.5rem;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}
.paper-card::before {
  content: '';
  position: absolute; top: 0; left: 0;
  width: 4px; height: 100%;
  background: var(--accent);
  opacity: 0;
  transition: opacity var(--transition);
}
.paper-card:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--border);
  transform: translateY(-1px);
}
.paper-card:hover::before { opacity: 1; }

.paper-card__header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 0.4rem;
}
.paper-card__title {
  font-family: var(--font-display);
  font-size: 1.12rem;
  font-weight: 400;
  color: var(--ink);
  line-height: 1.4;
}
.paper-card__authors {
  font-size: 0.88rem;
  color: var(--ink-secondary);
  margin-bottom: 0.2rem;
}
.paper-card__venue {
  font-size: 0.84rem;
  font-style: italic;
  color: var(--ink-muted);
  margin-bottom: 0.8rem;
}
.paper-card__abstract {
  font-size: 0.9rem;
  color: var(--ink-secondary);
  line-height: 1.7;
}
.paper-card__abstract p + p { margin-top: 0.5rem; }
.paper-card__links {
  margin-top: 1rem;
  display: flex; gap: 1rem;
}
.paper-card__links a {
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  padding: 0.35rem 0.9rem;
  border: 1px solid var(--border);
  border-radius: 4px;
  color: var(--ink-secondary);
  transition: all var(--transition);
}
.paper-card__links a:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-subtle);
}

/* Badges */
.badge {
  display: inline-block;
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 4px 10px;
  border-radius: 4px;
  white-space: nowrap;
  flex-shrink: 0;
}
.badge--jmp       { background: linear-gradient(135deg, #d4a054, #e2b36a); color: #1c2333; }
.badge--published { background: #e4f0e0; color: #2d6a1e; }
.badge--revise    { background: #fff3db; color: #7a5d1e; }
.badge--working   { background: #e5eaf4; color: #3a4e78; }

/* --- Course Cards (Teaching) --- */
.course-card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius);
  padding: 1.5rem 1.8rem;
  margin-bottom: 1.2rem;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition);
}
.course-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}
.course-card__title {
  font-weight: 600; font-size: 1rem;
  margin-bottom: 0.15rem; color: var(--ink);
}
.course-card__meta {
  font-size: 0.84rem; color: var(--ink-muted); margin-bottom: 0.6rem;
  display: flex; align-items: center; gap: 0.5rem;
}
.course-card__meta .role-tag {
  font-size: 0.68rem; font-weight: 700; text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 2px 8px; border-radius: 3px;
  background: var(--accent-subtle); color: var(--accent);
}
.course-card__desc {
  font-size: 0.9rem; color: var(--ink-secondary); line-height: 1.65;
}

/* --- CV Sections --- */
.cv-download-btn {
  display: inline-flex; align-items: center; gap: 0.6rem;
  padding: 0.75rem 1.6rem;
  background: linear-gradient(135deg, var(--accent), var(--accent-hover));
  color: var(--sidebar-bg);
  border-radius: 6px;
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  transition: all var(--transition);
  box-shadow: 0 2px 8px rgba(212,160,84,0.25);
  margin-bottom: 2.5rem;
}
.cv-download-btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(212,160,84,0.35);
  color: var(--sidebar-bg);
}

.cv-group { margin-bottom: 2.5rem; }
.cv-group__title {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 400;
  margin-bottom: 1.2rem;
  padding-bottom: 0.6rem;
  border-bottom: 2px solid var(--border-light);
  color: var(--ink);
}
.cv-item { margin-bottom: 1.2rem; padding-left: 1rem; border-left: 2px solid var(--border-light); }
.cv-item__row {
  display: flex; justify-content: space-between;
  align-items: baseline; flex-wrap: wrap; gap: 0.5rem;
}
.cv-item__title  { font-weight: 600; font-size: 0.93rem; color: var(--ink); }
.cv-item__date   { font-size: 0.82rem; color: var(--ink-muted); white-space: nowrap; }
.cv-item__sub    { font-size: 0.88rem; color: var(--ink-secondary); }
.cv-item__detail { font-size: 0.88rem; color: var(--ink-secondary); margin-top: 0.15rem; }

/* --- Bio Prose --- */
.bio-text {
  font-size: 1rem;
  color: var(--ink-secondary);
  line-height: 1.78;
}
.bio-text p { margin-bottom: 1rem; }
.bio-text strong { color: var(--ink); font-weight: 600; }

/* --- Footer --- */
.site-footer {
  margin-top: 3rem;
  padding: 2rem 0;
  border-top: 1px solid var(--border-light);
  text-align: center;
  font-size: 0.78rem;
  color: var(--ink-muted);
}

/* --- Animations --- */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(16px); }
  to   { opacity: 1; transform: translateY(0); }
}
.animate-in {
  animation: fadeUp 0.5s ease forwards;
  opacity: 0;
}
.animate-in:nth-child(1) { animation-delay: 0.05s; }
.animate-in:nth-child(2) { animation-delay: 0.12s; }
.animate-in:nth-child(3) { animation-delay: 0.19s; }
.animate-in:nth-child(4) { animation-delay: 0.26s; }
.animate-in:nth-child(5) { animation-delay: 0.33s; }

/* =========================================
   MOBILE RESPONSIVE
   ========================================= */
.mobile-header {
  display: none;
  position: sticky; top: 0; z-index: 100;
  background: var(--sidebar-bg);
  padding: 1rem 1.5rem;
  align-items: center;
  justify-content: space-between;
}
.mobile-header__name {
  font-family: var(--font-display);
  color: var(--sidebar-heading);
  font-size: 1.1rem;
}
.mobile-header__toggle {
  background: none; border: none; cursor: pointer; padding: 4px;
}
.mobile-header__toggle span {
  display: block; width: 22px; height: 2px;
  background: var(--sidebar-text); margin: 5px 0;
  transition: 0.3s;
}

@media (max-width: 860px) {
  .sidebar { transform: translateX(-100%); transition: transform 0.3s ease; }
  .sidebar.open { transform: translateX(0); }
  .mobile-header { display: flex; }
  .main { margin-left: 0; }
  .content { padding: 2rem 1.5rem 3rem; }

  /* overlay when sidebar open */
  .sidebar-overlay {
    display: none;
    position: fixed; inset: 0;
    background: rgba(0,0,0,0.5);
    z-index: 90;
  }
  .sidebar-overlay.active { display: block; }
}