/* ============================================================
   Personal Academic Website — Phat Tuan Tran-Truong
   Design System & Styles
   ============================================================ */

/* ---------- Google Font ---------- */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&family=JetBrains+Mono:wght@400;500&display=swap');

/* ---------- CSS Custom Properties ---------- */
:root {
  /* colours */
  --bg-primary:    #0a0e1a;
  --bg-secondary:  #111827;
  --bg-card:       rgba(17, 24, 39, 0.65);
  --bg-card-hover: rgba(30, 41, 59, 0.80);
  --border-card:   rgba(99, 102, 241, 0.15);
  --border-glow:   rgba(99, 102, 241, 0.35);

  --accent-1: #6366f1;          /* indigo */
  --accent-2: #06b6d4;          /* cyan */
  --accent-3: #a855f7;          /* purple */
  --accent-gradient: linear-gradient(135deg, var(--accent-1), var(--accent-2));
  --accent-gradient-2: linear-gradient(135deg, var(--accent-3), var(--accent-1));

  --text-primary:   #f1f5f9;
  --text-secondary: #94a3b8;
  --text-tertiary:  #64748b;
  --text-accent:    var(--accent-2);

  /* Sizing */
  --max-width: 1200px;
  --nav-height: 70px;
  --section-padding: 100px 0;
  --card-radius: 16px;
  --card-blur: 16px;

  /* Shadows */
  --shadow-card: 0 8px 32px rgba(0, 0, 0, 0.35);
  --shadow-glow: 0 0 30px rgba(99, 102, 241, 0.10);

  /* Transitions */
  --ease: cubic-bezier(0.4, 0, 0.2, 1);
  --transition-fast: 0.2s var(--ease);
  --transition-med:  0.4s var(--ease);
  --transition-slow: 0.6s var(--ease);
  
  /* Tag colors (Default/Dark) */
  --tag-bg: rgba(254, 240, 138, 0.12);
  --tag-border: rgba(254, 240, 138, 0.20);
  --tag-text: #fef08a;
}

/* ---------- Light theme overrides ---------- */
body.light{
  --bg-primary:    #f4f6fb;
  --bg-secondary:  #e9ecf2;
  --bg-card:       rgba(255, 255, 255, 0.78);
  --bg-card-hover: rgba(240, 242, 248, 0.90);
  --border-card:   rgba(99, 102, 241, 0.18);
  --border-glow:   rgba(99, 102, 241, 0.35);

  --text-primary:   #1e293b;
  --text-secondary: #475569;
  --text-tertiary:  #64748b;

  --shadow-card: 0 8px 32px rgba(0, 0, 0, 0.08);
  --shadow-glow: 0 0 30px rgba(99, 102, 241, 0.12);

  /* Tag colors (Light) */
  --tag-bg: #fef9c3;
  --tag-border: #fef08a;
  --tag-text: #854d0e;
}

/* ---------- Reset & Base ---------- */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0;}
html{scroll-behavior:smooth;font-size:16px;scroll-padding-top:var(--nav-height);}
body{
  font-family:'Inter',system-ui,sans-serif;
  background:var(--bg-primary);
  color:var(--text-primary);
  line-height:1.7;
  overflow-x:hidden;
  -webkit-font-smoothing:antialiased;
  transition:background .4s var(--ease), color .4s var(--ease);
}
a{color:var(--text-accent);text-decoration:none;transition:color var(--transition-fast);}
a:hover{color:var(--accent-1);}
img{max-width:100%;display:block;}
ul{list-style:none;}

/* ---------- Utility ---------- */
.container{max-width:var(--max-width);margin:0 auto;padding:0 clamp(1rem,4vw,2.5rem);}
.section-title{
  font-size:clamp(1.8rem,4vw,2.4rem);
  font-weight:800;
  margin-bottom:1rem;
  position:relative;
  display:inline-block;
}
.section-title::after{
  content:'';display:block;
  width:60px;height:4px;
  border-radius:4px;
  background:var(--accent-gradient);
  margin-top:.6rem;
}
.section-subtitle{
  color:var(--text-secondary);
  font-size:1.05rem;
  max-width:700px;
  margin-bottom:3rem;
}
.badge{
  display:inline-block;
  padding:4px 12px;
  border-radius:99px;
  font-size:.75rem;
  font-weight:600;
  letter-spacing:.03em;
  background:rgba(99,102,241,.12);
  color:var(--accent-1);
  border:1px solid rgba(99,102,241,.25);
}
.badge--cyan{
  background:rgba(6,182,212,.12);
  color:var(--accent-2);
  border-color:rgba(6,182,212,.25);
}
.badge--purple{
  background:rgba(168,85,247,.12);
  color:var(--accent-3);
  border-color:rgba(168,85,247,.25);
}
.badge--red{
  background:rgba(239,68,68,.12);
  color:#ef4444;
  border-color:rgba(239,68,68,.25);
}

/* ---------- Animated background ---------- */
.bg-grid{
  position:fixed;inset:0;z-index:0;pointer-events:none;
  background-image:
    radial-gradient(circle at 20% 30%, rgba(99,102,241,.07) 0, transparent 50%),
    radial-gradient(circle at 80% 70%, rgba(6,182,212,.06) 0, transparent 50%);
  transition:background-image .4s var(--ease);
}
body.light .bg-grid{
  background-image:
    radial-gradient(circle at 20% 30%, rgba(99,102,241,.10) 0, transparent 50%),
    radial-gradient(circle at 80% 70%, rgba(6,182,212,.08) 0, transparent 50%);
}
.bg-grid::before{
  content:'';position:absolute;inset:0;
  background-size:60px 60px;
  background-image:
    linear-gradient(to right,rgba(99,102,241,.04) 1px,transparent 1px),
    linear-gradient(to bottom,rgba(99,102,241,.04) 1px,transparent 1px);
}
body.light .bg-grid::before{
  background-image:
    linear-gradient(to right,rgba(99,102,241,.06) 1px,transparent 1px),
    linear-gradient(to bottom,rgba(99,102,241,.06) 1px,transparent 1px);
}

/* ---------- Scroll reveal ---------- */
.reveal{
  opacity:0;
  transform:translateY(40px);
  transition:opacity .7s var(--ease), transform .7s var(--ease);
}
.reveal.visible{
  opacity:1;
  transform:translateY(0);
}

/* =====================  NAVIGATION  ===================== */
.navbar{
  position:fixed;top:0;left:0;width:100%;
  height:var(--nav-height);
  z-index:1000;
  display:flex;align-items:center;
  transition:background var(--transition-med), box-shadow var(--transition-med);
}
.navbar.scrolled{
  background:rgba(10,14,26,.92);
  backdrop-filter:blur(14px);
  box-shadow:0 2px 20px rgba(0,0,0,.4);
}
body.light .navbar.scrolled{
  background:rgba(244,246,251,.92);
  box-shadow:0 2px 20px rgba(0,0,0,.08);
}
/* ---------- Theme toggle button ---------- */
.theme-toggle{
  background:transparent;
  border:1px solid var(--border-card);
  border-radius:10px;
  padding:8px 10px;
  cursor:pointer;
  display:flex;align-items:center;justify-content:center;
  color:var(--text-secondary);
  font-size:1rem;
  transition:all var(--transition-fast);
  position:relative;
  overflow:hidden;
  width:38px;height:38px;
}
.theme-toggle:hover{
  border-color:var(--border-glow);
  color:var(--text-primary);
  box-shadow:var(--shadow-glow);
}
#theme-icon-light{display:none;}
body.light #theme-icon-dark{display:none;}
body.light #theme-icon-light{display:block;color:#f59e0b;}
.navbar .container{display:flex;align-items:center;justify-content:space-between;width:100%;}
.nav-logo{
  font-size:1.3rem;font-weight:800;
  background:var(--accent-gradient);
  -webkit-background-clip:text;-webkit-text-fill-color:transparent;
  letter-spacing:-.02em;
}
.nav-links{display:flex;gap:2rem;align-items:center;}
.nav-links a{
  color:var(--text-secondary);font-size:.88rem;font-weight:500;
  position:relative;
  transition:color var(--transition-fast);
}
.nav-links a::after{
  content:'';position:absolute;bottom:-4px;left:0;
  width:0;height:2px;border-radius:2px;
  background:var(--accent-gradient);
  transition:width var(--transition-fast);
}
.nav-links a:hover,
.nav-links a.active{color:var(--text-primary);}
.nav-links a:hover::after,
.nav-links a.active::after{width:100%;}

/* hamburger */
.hamburger{display:none;flex-direction:column;gap:5px;cursor:pointer;z-index:1001;}
.hamburger span{display:block;width:24px;height:2px;background:var(--text-primary);border-radius:2px;transition:all var(--transition-fast);}
.hamburger.open span:nth-child(1){transform:rotate(45deg) translate(5px,5px);}
.hamburger.open span:nth-child(2){opacity:0;}
.hamburger.open span:nth-child(3){transform:rotate(-45deg) translate(5px,-5px);}

/* =====================  HERO  ===================== */
.hero{
  min-height:100vh;
  display:flex;align-items:center;
  position:relative;
  padding-top:calc(var(--nav-height) + 2rem);
  overflow:hidden;
}
.hero .container{
  display:flex;align-items:center;gap:4rem;
  flex-wrap:wrap;
}
.hero-text{flex:1 1 500px;}
.hero-greeting{
  font-size:1.1rem;font-weight:500;
  color:var(--text-secondary);
  margin-bottom:.6rem;
  display:flex;align-items:center;gap:.5rem;
}
.hero-greeting .wave{display:inline-block;animation:wave 2.5s infinite;transform-origin:70% 70%;}
@keyframes wave{
  0%,60%,100%{transform:rotate(0)}
  10%{transform:rotate(14deg)}
  20%{transform:rotate(-8deg)}
  30%{transform:rotate(14deg)}
  40%{transform:rotate(-4deg)}
  50%{transform:rotate(10deg)}
}
.hero-name{
  font-size:clamp(2.6rem,6vw,4rem);
  font-weight:900;
  line-height:1.1;
  margin-bottom:.8rem;
}
.hero-name .gradient-text{
  background:var(--accent-gradient);
  -webkit-background-clip:text;-webkit-text-fill-color:transparent;
}
.hero-role-lines{
  margin-bottom:1.5rem;
}
.hero-role-lines p{
  font-size:clamp(.95rem,2vw,1.15rem);
  color:var(--text-secondary);
  line-height:1.6;
}
.hero-role-lines p:first-child{
  font-weight:600;
  color:var(--text-primary);
}

.hero-links{display:flex;flex-wrap:wrap;gap:.8rem;margin-top:1rem;}
.hero-links a{
  display:inline-flex;align-items:center;gap:.5rem;
  padding:10px 20px;border-radius:10px;
  font-size:.88rem;font-weight:600;
  border:1px solid var(--border-card);
  background:var(--bg-card);
  backdrop-filter:blur(var(--card-blur));
  color:var(--text-primary);
  transition:all var(--transition-fast);
}
.hero-links a:hover{
  border-color:var(--border-glow);
  box-shadow:var(--shadow-glow);
  transform:translateY(-2px);
}
.hero-links a svg{width:18px;height:18px;}

.hero-photo{
  flex:0 0 280px;
  position:relative;
}
.hero-photo-wrapper{
  width:280px;height:280px;
  border-radius:50%;
  background:var(--accent-gradient);
  padding:4px;
  position:relative;
  animation:float 6s ease-in-out infinite;
}
.hero-photo-wrapper img{
  width:100%;height:100%;
  border-radius:50%;
  object-fit:cover;
  background:var(--bg-secondary);
}
@keyframes float{
  0%,100%{transform:translateY(0)}
  50%{transform:translateY(-14px)}
}
.hero-photo-wrapper::after{
  content:'';position:absolute;inset:-8px;
  border-radius:50%;
  border:2px dashed rgba(99,102,241,.25);
  animation:spin 20s linear infinite;
}
@keyframes spin{to{transform:rotate(360deg)}}

/* =====================  ABOUT / RESEARCH INTERESTS  ===================== */
#about{padding:var(--section-padding);}
.about-grid{
  display:grid;
  grid-template-columns:repeat(auto-fit,minmax(320px,1fr));
  gap:2rem;
  margin-top:2rem;
}
.about-card{
  background:var(--bg-card);
  border:1px solid var(--border-card);
  border-radius:var(--card-radius);
  backdrop-filter:blur(var(--card-blur));
  padding:2rem;
  transition:all var(--transition-med);
}
.about-card:hover{
  border-color:var(--border-glow);
  box-shadow:var(--shadow-glow);
  transform:translateY(-4px);
}
.about-card h3{
  font-size:1.15rem;font-weight:700;
  margin-bottom:1rem;
  display:flex;align-items:center;gap:.6rem;
}
.about-card h3 .icon{
  font-size:1.4rem;
  background:var(--accent-gradient);
  -webkit-background-clip:text;-webkit-text-fill-color:transparent;
}
.about-card p,.about-card ul{color:var(--text-secondary);font-size:.94rem;}
.about-card ul{display:flex;flex-wrap:wrap;gap:.5rem;}
.about-card ul li{
  padding:5px 14px;border-radius:8px;
  background:rgba(99,102,241,.08);
  border:1px solid rgba(99,102,241,.15);
  font-size:.82rem;font-weight:500;
  color:var(--text-primary);
  transition:all var(--transition-fast);
}
.about-card ul li:hover{
  background:rgba(99,102,241,.18);
  border-color:var(--accent-1);
}

/* =====================  NEWS  ===================== */
#news{padding:var(--section-padding);background:var(--bg-secondary);}
.news-list{display:grid;gap:1rem;margin-top:2rem;}
.news-item{
  display:flex;gap:1.2rem;align-items:flex-start;
  padding:1.2rem 1.6rem;
  border-radius:12px;
  background:var(--bg-card);
  border:1px solid var(--border-card);
  backdrop-filter:blur(var(--card-blur));
  transition:all var(--transition-fast);
}
.news-item:hover{border-color:var(--border-glow);transform:translateX(6px);}
.news-date{
  flex-shrink:0;
  font-size:.78rem;font-weight:700;
  color:var(--accent-2);
  padding:4px 10px;
  border-radius:6px;
  background:rgba(6,182,212,.1);
  white-space:nowrap;
}
.news-item p{color:var(--text-secondary);font-size:.92rem;}
.news-item p a{font-weight:600;}

/* =====================  EDUCATION  ===================== */
#education{padding:var(--section-padding);}
.timeline{position:relative;margin-top:2rem;}
.timeline::before{
  content:'';position:absolute;left:20px;top:0;bottom:0;
  width:2px;background:linear-gradient(to bottom,var(--accent-1),var(--accent-2));
  border-radius:2px;
}
.timeline-item{display:flex;gap:2rem;margin-bottom:2.5rem;position:relative;}
.timeline-dot{
  flex-shrink:0;
  width:42px;height:42px;
  border-radius:50%;
  background:var(--bg-primary);
  border:2px solid var(--accent-1);
  display:flex;align-items:center;justify-content:center;
  color:var(--accent-2);font-size:1.1rem;
  z-index:1;
  transition:all var(--transition-fast);
}
.timeline-item:hover .timeline-dot{
  background:var(--accent-1);color:#fff;
  box-shadow:0 0 20px rgba(99,102,241,.4);
}
.timeline-content{
  flex:1;
  background:var(--bg-card);
  border:1px solid var(--border-card);
  border-radius:var(--card-radius);
  backdrop-filter:blur(var(--card-blur));
  padding:1.5rem 2rem;
  transition:all var(--transition-med);
}
.timeline-content:hover{
  border-color:var(--border-glow);
  box-shadow:var(--shadow-glow);
}
.timeline-content h3{font-size:1.1rem;font-weight:700;margin-bottom:.3rem;}
.timeline-content .institution{color:var(--accent-2);font-size:.92rem;font-weight:600;margin-bottom:.5rem;}
.timeline-content .date{color:var(--text-tertiary);font-size:.82rem;margin-bottom:.6rem;}
.timeline-content ul{padding-left:1.2rem;list-style:disc;}
.timeline-content ul li{color:var(--text-secondary);font-size:.9rem;margin-bottom:.3rem;}
.timeline-content ul li strong{color:var(--text-primary);}

/* =====================  EXPERIENCE  ===================== */
#experience{padding:var(--section-padding);background:var(--bg-secondary);}
.experience-cards{display:grid;gap:1.5rem;margin-top:2rem;}
.exp-card{
  background:var(--bg-card);
  border:1px solid var(--border-card);
  border-radius:var(--card-radius);
  backdrop-filter:blur(var(--card-blur));
  padding:2rem;
  transition:all var(--transition-med);
}
.exp-card:hover{
  border-color:var(--border-glow);
  box-shadow:var(--shadow-glow);
  transform:translateY(-3px);
}
.exp-card-header{display:flex;justify-content:space-between;align-items:flex-start;flex-wrap:wrap;gap:.8rem;margin-bottom:1rem;}
.exp-card-header h3{font-size:1.1rem;font-weight:700;}
.exp-card-header .org{color:var(--accent-2);font-size:.92rem;font-weight:600;}
.exp-card-header .date{color:var(--text-tertiary);font-size:.82rem;white-space:nowrap;}
.exp-card ul{padding-left:1.2rem;list-style:disc;}
.exp-card ul li{color:var(--text-secondary);font-size:.9rem;margin-bottom:.35rem;}
.exp-card-projects{margin-top:1rem;}
.exp-card-projects h4{font-size:.95rem;font-weight:700;margin-bottom:.6rem;color:var(--accent-3);}
.project-tag{
  display:inline-block;padding:3px 10px;
  border-radius:6px;font-size:.72rem;font-weight:700;
  margin-right:.4rem;
}
.project-tag.research{background:rgba(239,68,68,.12);color:#ef4444;}
.project-tag.application{background:rgba(34,197,94,.12);color:#22c55e;}
.project-tag.ongoing{background:rgba(251,191,36,.12);color:#fbbf24;}
.project-tag.finished{background:rgba(99,102,241,.12);color:var(--accent-1);}

/* =====================  PUBLICATIONS  ===================== */
#publications{padding:var(--section-padding);}
.pub-filters{
  display:flex;gap:.6rem;flex-wrap:wrap;
  margin-bottom:2rem;
}
.pub-filter-btn{
  padding:8px 18px;
  border-radius:10px;
  border:1px solid var(--border-card);
  background:transparent;
  color:var(--text-secondary);
  font-family:inherit;font-size:.85rem;font-weight:600;
  cursor:pointer;
  transition:all var(--transition-fast);
}
.pub-filter-btn:hover,.pub-filter-btn.active{
  background:var(--accent-gradient);
  color:#fff;border-color:transparent;
}
.pub-count{
  display:inline-flex;align-items:center;justify-content:center;
  min-width:22px;height:22px;
  padding:0 6px;
  border-radius:99px;
  font-size:.72rem;font-weight:700;
  background:rgba(255,255,255,.15);
  margin-left:6px;
}
.pub-filter-btn.active .pub-count{
  background:rgba(255,255,255,.25);
}
.pub-role-legend{
  margin:-.5rem auto 2.5rem;
  text-align:center;
  font-size:.85rem;
  color:var(--text-secondary);
  opacity:.8;
}
.pub-role-legend span{
  color:var(--accent-2);
  font-weight:700;
  margin-right:2px;
}
.pub-list{display:grid;gap:1rem;}
.pub-item{
  display:flex;gap:1rem;
  padding:1.2rem 1.6rem;
  border-radius:12px;
  background:var(--bg-card);
  border:1px solid var(--border-card);
  backdrop-filter:blur(var(--card-blur));
  transition:all var(--transition-fast);
}
.pub-item.hidden {
  display: none !important;
}

.pub-scholar-link {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 8px 20px;
  background: rgba(99, 102, 241, 0.08);
  color: var(--accent-1);
  border-radius: 50px;
  font-weight: 600;
  font-size: 0.9rem;
  transition: all var(--transition-fast);
  text-decoration: none;
  border: 1px solid rgba(99, 102, 241, 0.15);
  margin-top: 0.5rem;
}

.pub-scholar-link i {
  font-size: 1.1rem;
}

.pub-scholar-link:hover {
  background: var(--accent-1);
  color: #fff !important;
  transform: translateY(-2px);
  box-shadow: 0 4px 15px rgba(99, 102, 241, 0.25);
}

/* --- Publication Search --- */
.pub-search-container {
  max-width: 600px;
  margin: 0 auto 2rem;
}

.pub-search-group {
  position: relative;
  display: flex;
  align-items: center;
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: 12px;
  padding: 0.8rem 1.2rem;
  transition: all var(--transition-fast);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

.pub-search-group:focus-within {
  border-color: var(--accent-1);
  box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.1), 0 8px 30px rgba(0, 0, 0, 0.15);
  transform: translateY(-2px);
}

#pub-search-clear {
  background: transparent;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  padding: 0.5rem;
  opacity: 0;
  pointer-events: none;
  transition: all var(--transition-fast);
}

#pub-search-clear.visible {
  opacity: 1;
  pointer-events: auto;
}

#pub-search-clear:hover {
  color: var(--accent-1);
}

.search-icon {
  color: var(--accent-1);
  font-size: 1.1rem;
  margin-right: 1rem;
}

#pub-search-input {
  flex: 1;
  background: transparent;
  border: none;
  color: var(--text-primary);
  font-size: 1rem;
  font-family: inherit;
  outline: none;
  width: 100%;
}

.pub-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 0.8rem;
  margin-bottom: 0.5rem;
}

.pub-tag {
  font-size: 0.72rem;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: 40px;
  background: var(--tag-bg);
  color: var(--tag-text);
  border: 1px solid var(--tag-border);
  transition: all var(--transition-fast);
  text-transform: uppercase;
  letter-spacing: 0.02em;
}

#pub-search-input::placeholder {
  color: var(--text-secondary);
  opacity: 0.6;
}

#pub-search-clear {
  background: transparent;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  padding: 5px;
  font-size: 0.9rem;
  opacity: 0;
  pointer-events: none;
  transition: all var(--transition-fast);
}

#pub-search-clear.visible {
  opacity: 0.7;
  pointer-events: auto;
}

#pub-search-clear:hover {
  opacity: 1;
  color: var(--accent-1);
}

.pub-item:hover{border-color:var(--border-glow);transform:translateX(4px);}
.pub-item.hidden{display:none;}
.pub-item {
  min-width: 0; /* Prevent flex children from expanding */
}
.pub-year{
  flex-shrink:0;
  font-size:.82rem;font-weight:800;
  color:var(--accent-1);
  min-width:42px;
  padding-top:2px;
}
.pub-details {
  flex: 1;
  min-width: 0; /* Prevent flex children from expanding */
}
.pub-details .pub-title{font-size:.92rem;font-weight:600;margin-bottom:.3rem;}
.pub-details .pub-authors{color:var(--text-secondary);font-size:.84rem;margin-bottom:.2rem;}
.pub-details .pub-venue{color:var(--text-secondary);font-size:.84rem;margin-bottom:.4rem;font-style:italic;}
.pub-details .pub-venue strong{color:var(--accent-2);font-style:normal;}
.pub-details .pub-meta{display:flex;gap:.5rem;flex-wrap:wrap;align-items:center;}

.pub-abstract-btn {
  background: rgba(99, 102, 241, 0.1);
  color: var(--accent-1);
  border: 1px solid rgba(99, 102, 241, 0.2);
  padding: 4px 10px;
  border-radius: 6px;
  font-size: 0.78rem;
  font-weight: 600;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  transition: all var(--transition-fast);
  font-family: inherit;
}

.pub-abstract-btn:hover {
  background: var(--accent-1);
  color: #fff;
  transform: translateY(-2px);
}

.pub-abstract-btn.active {
  background: var(--accent-3);
  color: #fff;
  border-color: var(--accent-3);
}

.pub-abstract {
  display: none;
  margin-top: 1rem;
  padding: 1.2rem;
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-left: 3px solid var(--accent-1);
  border-radius: 0 12px 12px 0;
  font-size: 0.88rem;
  line-height: 1.6;
  color: var(--text-secondary);
  animation: slideDown 0.4s var(--ease) forwards;
}

.pub-abstract.active {
  display: block;
}

.abstract-title {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--accent-1);
  margin-bottom: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.abstract-title::after {
  content: '';
  flex: 1;
  height: 1px;
  background: linear-gradient(to right, rgba(99, 102, 241, 0.2), transparent);
}

.pub-bibtex-btn {
  background: rgba(168, 85, 247, 0.1);
  color: var(--accent-3);
  border: 1px solid rgba(168, 85, 247, 0.2);
  padding: 4px 10px;
  border-radius: 6px;
  font-size: 0.78rem;
  font-weight: 600;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  transition: all var(--transition-fast);
  font-family: inherit;
}

.pub-bibtex-btn:hover {
  background: var(--accent-3);
  color: #fff;
  transform: translateY(-2px);
}

.pub-bibtex-btn.active {
  background: var(--accent-1);
  color: #fff;
  border-color: var(--accent-1);
}

.pub-bibtex {
  display: none;
  margin-top: 1rem;
  padding: 1.2rem;
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-left: 3px solid var(--accent-3);
  border-radius: 0 12px 12px 0;
  font-size: 0.82rem;
  line-height: 1.5;
  color: var(--text-secondary);
  animation: slideDown 0.4s var(--ease) forwards;
  position: relative;
}

.pub-bibtex.active {
  display: block;
}

.bibtex-wrapper {
  position: relative;
  background: rgba(0, 0, 0, 0.2);
  border-radius: 8px;
  margin-top: 0.5rem;
  /* overflow moved to pre */
}

/* Custom scrollbar for BibTeX */
.pub-bibtex pre::-webkit-scrollbar {
  height: 6px;
}
.pub-bibtex pre::-webkit-scrollbar-track {
  background: rgba(255, 255, 255, 0.05);
  border-radius: 10px;
}
.pub-bibtex pre::-webkit-scrollbar-thumb {
  background: var(--accent-3);
  border-radius: 10px;
}

.pub-bibtex pre {
  margin: 0;
  padding: 1.2rem;
  padding-right: 3.5rem; /* Space for copy button */
  font-family: 'JetBrains Mono', monospace;
  color: var(--text-primary);
  white-space: pre;
  word-wrap: normal;
  overflow-x: auto; /* Scroll here instead of wrapper */
  display: block;
}

.pub-bibtex code {
  white-space: pre;
  display: block; /* Ensure it behaves as a block to avoid inline gaps */
  margin: 0;
  padding: 0;
}

.copy-bibtex {
  position: absolute;
  top: 0.75rem;
  right: 0.75rem;
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.2);
  color: var(--text-secondary);
  padding: 6px 10px;
  border-radius: 6px;
  cursor: pointer;
  transition: all var(--transition-fast);
  backdrop-filter: blur(4px);
  z-index: 5;
}

.copy-bibtex:hover {
  background: var(--accent-1);
  color: #fff;
}

@keyframes slideDown {
  from {
    opacity: 0;
    transform: translateY(-10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.pub-link{
  display:inline-flex;align-items:center;gap:.3rem;
  font-size:.78rem;font-weight:600;
  padding:3px 10px;border-radius:6px;
  background:rgba(6,182,212,.1);
  color:var(--accent-2);
  transition:all var(--transition-fast);
}
.pub-link:hover{background:rgba(6,182,212,.2);color:var(--accent-2);}

.pub-code{
  display:inline-flex;align-items:center;gap:.3rem;
  font-size:.78rem;font-weight:600;
  padding:3px 10px;border-radius:6px;
  background:rgba(168,85,247,.1);
  color:var(--accent-3);
  transition:all var(--transition-fast);
  text-decoration:none;
}
.pub-code:hover{background:rgba(168,85,247,.2);color:var(--accent-3);transform:translateY(-1px);}

/* =====================  AWARDS  ===================== */
#awards{padding:var(--section-padding);background:var(--bg-secondary);}
.awards-grid{
  display:grid;
  grid-template-columns:repeat(auto-fill,minmax(320px,1fr));
  gap:1.2rem;
  margin-top:2rem;
}
.award-card{
  background:var(--bg-card);
  border:1px solid var(--border-card);
  border-radius:var(--card-radius);
  backdrop-filter:blur(var(--card-blur));
  padding:1.6rem;
  transition:all var(--transition-med);
  display:flex;gap:1rem;align-items:flex-start;
}
.award-card:hover{border-color:var(--border-glow);box-shadow:var(--shadow-glow);transform:translateY(-3px);}
.award-icon{
  font-size:1.8rem;flex-shrink:0;
  background:var(--accent-gradient);
  -webkit-background-clip:text;-webkit-text-fill-color:transparent;
}
.award-card h4{font-size:.95rem;font-weight:700;margin-bottom:.3rem;}
.award-card p{color:var(--text-secondary);font-size:.84rem;}
.award-card .award-year{
  font-size:.78rem;font-weight:700;color:var(--accent-2);
  margin-top:.4rem;
}

/* =====================  SERVICES  ===================== */
#services{padding:var(--section-padding);}
.services-grid{
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:2rem;
  margin-top:2rem;
}
.service-card{
  background:var(--bg-card);
  border:1px solid var(--border-card);
  border-radius:var(--card-radius);
  backdrop-filter:blur(var(--card-blur));
  padding:2rem;
  transition:all var(--transition-med);
}
.service-card:hover{border-color:var(--border-glow);box-shadow:var(--shadow-glow);}
.service-card h3{font-size:1.1rem;font-weight:700;margin-bottom:1rem;display:flex;align-items:center;gap:.5rem;}
.service-list{display:flex;flex-wrap:wrap;gap:.5rem;}
.service-list li{
  padding:6px 14px;border-radius:8px;
  font-size:.82rem;font-weight:500;
  background:rgba(99,102,241,.08);
  border:1px solid rgba(99,102,241,.15);
  color:var(--text-primary);
  transition:all var(--transition-fast);
}
.service-list li:hover{background:rgba(99,102,241,.18);border-color:var(--accent-1);}

/* =====================  TEACHING  ===================== */
#teaching{padding:var(--section-padding);background:var(--bg-secondary);}
.teaching-grid{
  display:grid;
  grid-template-columns:repeat(auto-fill,minmax(340px,1fr));
  gap:1.2rem;
  margin-top:2rem;
}
.teaching-card{
  background:var(--bg-card);
  border:1px solid var(--border-card);
  border-radius:var(--card-radius);
  backdrop-filter:blur(var(--card-blur));
  padding:1.5rem;
  transition:all var(--transition-med);
}
.teaching-card:hover{border-color:var(--border-glow);box-shadow:var(--shadow-glow);transform:translateY(-3px);}
.teaching-card h4{font-size:.95rem;font-weight:700;margin-bottom:.4rem;}
.teaching-card p{color:var(--text-secondary);font-size:.85rem;margin-bottom:.3rem;}

.thesis-card {
  width: fit-content;
  margin-bottom: 2rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: 1.5rem 2.5rem;
}
.thesis-card h2 {
  font-size: 2.8rem;
  font-weight: 800;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  margin-bottom: 0.5rem;
  line-height: 1;
}
.thesis-card h4 {
  margin-bottom: 0 !important;
  font-size: 1rem !important;
  color: var(--text-primary);
}
.teaching-card .role-badge{
  display:inline-block;margin-top:.5rem;
  padding:3px 10px;border-radius:6px;
  font-size:.72rem;font-weight:700;
  background:rgba(6,182,212,.12);color:var(--accent-2);
}

.teaching-details {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease-out, opacity 0.3s ease;
  opacity: 0;
}

.teaching-details.active {
  max-height: 300px;
  opacity: 1;
  margin-top: 0.8rem;
  padding-top: 0.5rem;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.teaching-toggle-btn {
  background: rgba(99, 102, 241, 0.05);
  border: 1px solid rgba(99, 102, 241, 0.2);
  color: var(--accent-1);
  padding: 6px 14px;
  border-radius: 8px;
  font-size: 0.78rem;
  font-weight: 600;
  cursor: pointer;
  margin-top: 1rem;
  transition: all var(--transition-fast);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.teaching-toggle-btn:hover {
  background: var(--accent-1);
  color: #fff;
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(99, 102, 241, 0.2);
}

.teaching-toggle-btn i {
  transition: transform 0.3s ease;
  font-size: 0.7rem;
}

.teaching-toggle-btn.active {
  background: rgba(244, 63, 94, 0.05);
  border-color: rgba(244, 63, 94, 0.2);
  color: #f43f5e;
}

.teaching-toggle-btn.active:hover {
  background: #f43f5e;
  color: #fff;
}

/* =====================  SKILLS  ===================== */
#skills{padding:var(--section-padding);}
.skills-grid{
  display:grid;
  grid-template-columns:repeat(auto-fill,minmax(280px,1fr));
  gap:1.2rem;
  margin-top:2rem;
}
.skill-card{
  background:var(--bg-card);
  border:1px solid var(--border-card);
  border-radius:var(--card-radius);
  backdrop-filter:blur(var(--card-blur));
  padding:1.5rem;
  transition:all var(--transition-med);
}
.skill-card:hover{border-color:var(--border-glow);box-shadow:var(--shadow-glow);transform:translateY(-3px);}
.skill-card h4{font-size:.95rem;font-weight:700;margin-bottom:.8rem;display:flex;align-items:center;gap:.5rem;}
.skill-tags{display:flex;flex-wrap:wrap;gap:.4rem;}
.skill-tags span{
  padding:5px 12px;border-radius:8px;
  font-size:.8rem;font-weight:500;
  background:rgba(99,102,241,.08);
  border:1px solid rgba(99,102,241,.15);
  color:var(--text-primary);
  transition:all var(--transition-fast);
}
.skill-tags span:hover{background:rgba(99,102,241,.2);border-color:var(--accent-1);}

/* =====================  STUDENTS  ===================== */
.students-section {
  margin-top: 4rem;
}
.students-intro-text {
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 2rem;
  font-size: 0.95rem;
}
.students-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 1.2rem;
}
.student-project-card {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: var(--card-radius);
  padding: 1.5rem;
  backdrop-filter: blur(var(--card-blur));
  transition: all var(--transition-med);
}
.student-project-card:hover {
  border-color: var(--border-glow);
  box-shadow: var(--shadow-glow);
  transform: translateY(-3px);
}
.student-names {
  font-size: 0.98rem;
  font-weight: 700;
  margin-bottom: 0.6rem;
  color: var(--text-primary);
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 0.15rem;
}
.student-name-header {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}
.student-info-detail {
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--text-secondary);
  padding-left: 1.55rem;
  font-style: italic;
  opacity: 0.85;
}
.student-names i {
  color: var(--accent-1);
  font-size: 0.85rem;
}
.student-project-details {
  list-style: none;
  padding-left: 0;
  margin-top: 0.5rem;
}
.student-project-details li {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 0.2rem;
  display: flex;
  gap: 0.5rem;
}
.student-project-details li strong {
  color: var(--text-primary);
  min-width: 60px;
}
.project-topic {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.skill-subsection {
  margin-top: 1.2rem;
}
.skill-subsection:first-of-type {
  margin-top: 0.5rem;
}
.skill-sub-title {
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 0.6rem;
  opacity: 0.8;
}

.external-link-icon {
  font-size: 0.72rem;
  margin-left: 4px;
  opacity: 0.7;
  transition: opacity var(--transition-fast);
}

a:hover .external-link-icon {
  opacity: 1;
  color: var(--accent-1);
}

/* =====================  SOCIAL ACTIVITIES  ===================== */
#activities{padding:var(--section-padding);background:var(--bg-secondary);}
.activities-list{
  display:grid;
  grid-template-columns:repeat(auto-fill,minmax(340px,1fr));
  gap:1rem;
  margin-top:2rem;
}
.activity-item{
  display:flex;gap:1rem;align-items:flex-start;
  padding:1.2rem 1.4rem;
  border-radius:12px;
  background:var(--bg-card);
  border:1px solid var(--border-card);
  backdrop-filter:blur(var(--card-blur));
  transition:all var(--transition-fast);
}
.activity-item:hover{border-color:var(--border-glow);transform:translateY(-2px);}
.activity-icon{font-size:1.4rem;flex-shrink:0;}
.activity-item h4{font-size:.92rem;font-weight:700;margin-bottom:.2rem;}
.activity-item p{color:var(--text-secondary);font-size:.84rem;}

/* =====================  FOOTER  ===================== */
.footer{
  padding:60px 0 30px;
  border-top:1px solid var(--border-card);
  text-align:center;
}
.footer-links{display:flex;justify-content:center;gap:1.5rem;margin-bottom:1.5rem;flex-wrap:wrap;}
.footer-links a{
  display:inline-flex;align-items:center;gap:.4rem;
  color:var(--text-secondary);font-size:.88rem;font-weight:500;
  transition:color var(--transition-fast);
}
.footer-links a:hover{color:var(--text-accent);}
.footer p{color:var(--text-tertiary);font-size:.82rem;margin-top:.8rem;}

/* =====================  RESPONSIVE  ===================== */
@media(max-width:900px){
  .about-grid,.services-grid{grid-template-columns:1fr;}
  .hero .container{flex-direction:column-reverse;text-align:center;}
  .hero-links{justify-content:center;}
  .hero-photo{flex:0 0 220px;}
  .hero-photo-wrapper{width:220px;height:220px;}
}
@media(max-width:768px){
  .nav-links{
    position:fixed;top:0;right:-100%;
    width:280px;height:100vh;
    background:rgba(10,14,26,.98);
    backdrop-filter:blur(20px);
    flex-direction:column;
    padding:100px 2rem 2rem;
    gap:1.5rem;
    transition:right var(--transition-med);
  }
  .nav-links.open{right:0;}
  .hamburger{display:flex;}
  .awards-grid,.teaching-grid,.skills-grid,.activities-list{grid-template-columns:1fr;}
  .timeline::before{left:14px;}
  .timeline-dot{width:30px;height:30px;font-size:.85rem;}
}
@media(max-width:480px){
  :root{--section-padding:60px 0;}
  .hero-name{font-size:2rem;}
  .pub-item{flex-direction:column;gap:.5rem;}
  .pub-year{min-width:auto;}
}

/* ---------- Scrollbar ---------- */
::-webkit-scrollbar{width:8px;}
::-webkit-scrollbar-track{background:var(--bg-primary);}
::-webkit-scrollbar-thumb{background:var(--accent-1);border-radius:4px;}
::-webkit-scrollbar-thumb:hover{background:var(--accent-2);}

/* Light mode card adjustments */
body.light .about-card,
body.light .exp-card,
body.light .award-card,
body.light .service-card,
body.light .teaching-card,
body.light .skill-card,
body.light .pub-item,
body.light .news-item,
body.light .timeline-content,
body.light .activity-item{
  box-shadow:0 2px 12px rgba(0,0,0,.06);
}
body.light .pub-filter-btn{
  border-color:rgba(99,102,241,.25);
  color:var(--text-secondary);
}
body.light .hero-links a{
  box-shadow:0 2px 8px rgba(0,0,0,.06);
}