/* ================================================
   Dr. Deepak Upreti — Portfolio Stylesheet
   ================================================ */

/* ── CSS Variables (Light Mode) ── */
:root {
  --primary:        #1e40af;
  --primary-light:  #3b82f6;
  --primary-dark:   #1e3a8a;
  --secondary:      #0ea5e9;
  --accent:         #7c3aed;
  --accent-light:   #a78bfa;
  --success:        #059669;
  --warning:        #d97706;

  --bg:             #ffffff;
  --bg-alt:         #f8fafc;
  --bg-card:        #ffffff;
  --bg-nav:         rgba(255,255,255,0.96);
  --text:           #0f172a;
  --text-muted:     #64748b;
  --text-light:     #94a3b8;
  --border:         #e2e8f0;
  --border-light:   #f1f5f9;

  --shadow-sm:  0 1px 3px rgba(0,0,0,0.07);
  --shadow:     0 4px 16px rgba(0,0,0,0.08);
  --shadow-lg:  0 8px 32px rgba(0,0,0,0.12);
  --shadow-xl:  0 16px 48px rgba(0,0,0,0.16);

  --font-heading: 'Poppins', sans-serif;
  --font-body:    'Inter', sans-serif;

  --radius:    12px;
  --radius-lg: 20px;
  --transition: all 0.3s ease;
}

/* Dark Mode */
body.dark {
  --bg:             #0f172a;
  --bg-alt:         #1e293b;
  --bg-card:        #1e293b;
  --bg-nav:         rgba(15,23,42,0.97);
  --text:           #f1f5f9;
  --text-muted:     #94a3b8;
  --text-light:     #64748b;
  --border:         #334155;
  --border-light:   #1e293b;
  --shadow-sm:  0 1px 3px rgba(0,0,0,0.3);
  --shadow:     0 4px 16px rgba(0,0,0,0.35);
  --shadow-lg:  0 8px 32px rgba(0,0,0,0.45);
  --shadow-xl:  0 16px 48px rgba(0,0,0,0.55);
}

/* ── Reset ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html   { scroll-behavior: smooth; font-size: 16px; }
body   {
  font-family: var(--font-body);
  background: var(--bg); color: var(--text);
  line-height: 1.6; transition: background 0.3s, color 0.3s;
}
img    { max-width: 100%; height: auto; display: block; }
a      { text-decoration: none; color: inherit; transition: var(--transition); }
ul     { list-style: none; }
button { cursor: pointer; border: none; background: none; font-family: inherit; }

/* ── Typography ── */
h1,h2,h3,h4,h5,h6 { font-family: var(--font-heading); font-weight: 700; line-height: 1.25; color: var(--text); }
h1 { font-size: clamp(2rem,5vw,3.25rem); }
h2 { font-size: clamp(1.5rem,3.5vw,2.1rem); }
h3 { font-size: clamp(1rem,2vw,1.2rem); }
p  { color: var(--text-muted); margin-bottom: 1rem; }

/* ── Utilities ── */
.container   { max-width: 1140px; margin: 0 auto; padding: 0 1.5rem; }
.section-pad { padding: 88px 0; }
.text-center { text-align: center; }

.section-tag {
  display: inline-block;
  font-family: var(--font-heading); font-size: 0.7rem; font-weight: 700;
  letter-spacing: 3px; text-transform: uppercase;
  color: var(--primary); margin-bottom: 0.75rem;
}
.section-divider {
  width: 48px; height: 3px;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  border-radius: 2px; margin: 0.875rem 0 1.5rem;
}
.section-divider.center { margin: 0.875rem auto 1.5rem; }
.section-sub {
  max-width: 560px; color: var(--text-muted); font-size: 0.95rem; line-height: 1.75;
}
.section-sub.center { margin: 0 auto 2.5rem; }

/* ── Buttons ── */
.btn {
  display: inline-flex; align-items: center; gap: 0.5rem;
  padding: 11px 24px; border-radius: 8px;
  font-family: var(--font-heading); font-weight: 600; font-size: 0.85rem;
  letter-spacing: 0.3px; transition: var(--transition); cursor: pointer;
}
.btn-primary {
  background: var(--primary); color: #fff;
  box-shadow: 0 4px 12px rgba(30,64,175,0.3);
}
.btn-primary:hover { background: var(--primary-light); transform: translateY(-2px); box-shadow: 0 6px 18px rgba(30,64,175,0.4); }
.btn-outline { background: transparent; color: var(--primary); border: 2px solid var(--primary); }
.btn-outline:hover { background: var(--primary); color: #fff; transform: translateY(-2px); }
.btn-ghost { background: rgba(30,64,175,0.08); color: var(--primary); border: 1px solid rgba(30,64,175,0.15); }
.btn-ghost:hover { background: rgba(30,64,175,0.15); }
.btn-accent { background: var(--accent); color: #fff; box-shadow: 0 4px 12px rgba(124,58,237,0.3); }
.btn-accent:hover { background: var(--accent-light); transform: translateY(-2px); }
.btn-sm { padding: 7px 16px; font-size: 0.78rem; }
.btn-lg { padding: 14px 30px; font-size: 0.9rem; }

/* ══════════════════════════════════════
   NAVIGATION
══════════════════════════════════════ */
.navbar {
  position: fixed; top: 0; left: 0; width: 100%; z-index: 1000;
  background: var(--bg-nav); border-bottom: 1px solid var(--border);
  backdrop-filter: blur(14px); transition: var(--transition);
}
.navbar.scrolled { box-shadow: var(--shadow); }
.nav-inner {
  display: flex; align-items: center; justify-content: space-between;
  padding: 0.875rem 1.5rem; max-width: 1200px; margin: 0 auto;
}
.nav-logo { display: flex; align-items: center; gap: 0.75rem; }
.nav-logo-avatar {
  width: 38px; height: 38px; border-radius: 10px; flex-shrink: 0;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  display: flex; align-items: center; justify-content: center;
  font-family: var(--font-heading); font-weight: 800; font-size: 0.8rem; color: #fff;
}
.nav-logo-text   { display: flex; flex-direction: column; }
.nav-logo-name   { font-family: var(--font-heading); font-weight: 700; font-size: 0.9rem; color: var(--text); line-height: 1; }
.nav-logo-title  { font-size: 0.62rem; color: var(--text-muted); }
.nav-menu { display: flex; align-items: center; gap: 0.15rem; }
.nav-link {
  font-family: var(--font-heading); font-weight: 600; font-size: 0.75rem;
  letter-spacing: 0.3px; color: var(--text-muted);
  padding: 0.4rem 0.65rem; border-radius: 6px; transition: var(--transition);
}
.nav-link:hover,
.nav-link.active { color: var(--primary); background: rgba(30,64,175,0.08); }
.nav-actions { display: flex; align-items: center; gap: 0.6rem; }
.theme-toggle {
  width: 36px; height: 36px; border-radius: 8px;
  background: var(--bg-alt); border: 1px solid var(--border);
  display: flex; align-items: center; justify-content: center;
  color: var(--text-muted); font-size: 0.9rem; transition: var(--transition);
}
.theme-toggle:hover { color: var(--primary); border-color: var(--primary); }
.nav-toggle { display: none; flex-direction: column; gap: 5px; padding: 5px; z-index: 1001; }
.nav-toggle span { width: 22px; height: 2px; background: var(--text); border-radius: 2px; transition: var(--transition); display: block; }
.nav-toggle.open span:nth-child(1) { transform: rotate(45deg) translate(5px,5px); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: rotate(-45deg) translate(5px,-5px); }

/* ══════════════════════════════════════
   HERO SECTION
══════════════════════════════════════ */
.hero {
  min-height: 100vh; background: var(--bg);
  display: flex; align-items: center;
  padding-top: 80px; position: relative; overflow: hidden;
}
.hero-bg {
  position: absolute; inset: 0; pointer-events: none; overflow: hidden;
}
.hero-blob {
  position: absolute; border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  filter: blur(80px); opacity: 0.06;
}
.hero-blob-1 { width: 500px; height: 500px; top: -150px; right: 5%; }
.hero-blob-2 { width: 350px; height: 350px; bottom: 5%; left: -80px; background: linear-gradient(135deg, var(--secondary), var(--primary)); }
.hero-blob-3 { width: 200px; height: 200px; top: 30%; right: 25%; opacity: 0.04; }

.hero-inner {
  display: grid; grid-template-columns: 1fr 320px;
  gap: 4rem; align-items: center;
  max-width: 1140px; margin: 0 auto;
  padding: 60px 1.5rem 80px; width: 100%;
}
.hero-greeting {
  font-family: var(--font-heading); font-size: 1rem; font-weight: 600;
  color: var(--primary); letter-spacing: 1px; margin-bottom: 0.5rem;
  display: flex; align-items: center; gap: 0.5rem;
}
.hero-greeting::before {
  content: ''; display: block; width: 28px; height: 2px;
  background: var(--primary); border-radius: 2px;
}
.hero h1 { line-height: 1.15; margin-bottom: 0.75rem; }
.hero h1 .name-grad {
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 60%, var(--secondary) 100%);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}
.hero-typing {
  font-family: var(--font-heading); font-size: 1.15rem; font-weight: 600;
  color: var(--text-muted); margin-bottom: 1.5rem; min-height: 1.75em;
  display: flex; align-items: center; gap: 0;
}
.typing-cursor {
  display: inline-block; width: 2px; height: 1.1em;
  background: var(--primary); margin-left: 2px;
  animation: blink 1s step-end infinite; vertical-align: middle;
}
@keyframes blink { 0%,100% { opacity: 1; } 50% { opacity: 0; } }
.hero-bio {
  max-width: 540px; font-size: 0.95rem; line-height: 1.85;
  color: var(--text-muted); margin-bottom: 2rem;
}
.hero-buttons { display: flex; flex-wrap: wrap; gap: 0.875rem; margin-bottom: 3rem; }
.hero-divider { height: 1px; background: var(--border); max-width: 500px; margin-bottom: 2rem; }
.hero-stats { display: flex; gap: 2.5rem; flex-wrap: wrap; }
.hero-stat h3 {
  font-size: 2.2rem; font-weight: 800;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
  margin: 0; line-height: 1;
}
.hero-stat p { font-size: 0.72rem; color: var(--text-light); margin: 0.25rem 0 0; text-transform: uppercase; letter-spacing: 1.2px; font-family: var(--font-heading); font-weight: 600; }

/* Profile Photo */
.hero-photo-wrap { display: flex; justify-content: center; align-items: center; }
.profile-photo-ring {
  position: relative; display: flex; align-items: center; justify-content: center;
}
.profile-photo {
  width: 280px; height: 280px; border-radius: 50%;
  background: linear-gradient(135deg, #1e40af 0%, #7c3aed 60%, #0ea5e9 100%);
  display: flex; align-items: center; justify-content: center;
  font-family: var(--font-heading); font-weight: 800; font-size: 4.5rem;
  color: rgba(255,255,255,0.85); position: relative; overflow: hidden;
  box-shadow: 0 0 0 6px var(--bg), 0 0 0 10px rgba(30,64,175,0.2), var(--shadow-xl);
  z-index: 2;
}
.profile-photo img { width: 100%; height: 100%; object-fit: cover; border-radius: 50%; }
.profile-ring {
  position: absolute; inset: -18px; border-radius: 50%;
  border: 2px dashed rgba(30,64,175,0.3);
  animation: spinRing 25s linear infinite;
}
@keyframes spinRing { to { transform: rotate(360deg); } }
.profile-badge {
  position: absolute; bottom: -8px; left: 50%; transform: translateX(-50%);
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: 50px; padding: 0.4rem 1rem;
  display: flex; align-items: center; gap: 0.5rem;
  font-family: var(--font-heading); font-weight: 700; font-size: 0.72rem;
  color: var(--primary); box-shadow: var(--shadow); white-space: nowrap; z-index: 3;
}

/* ══════════════════════════════════════
   SECTION BASE
══════════════════════════════════════ */
section { position: relative; }
.bg-alt { background: var(--bg-alt); }
.section-header { margin-bottom: 2.5rem; }

/* ══════════════════════════════════════
   ABOUT SECTION
══════════════════════════════════════ */
.about-grid { display: grid; grid-template-columns: 300px 1fr; gap: 4rem; align-items: start; }
.about-photo-col { position: sticky; top: 100px; }
.about-portrait {
  width: 100%; aspect-ratio: 4/5; max-width: 300px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 70%);
  border-radius: var(--radius-lg); position: relative; overflow: hidden;
  display: flex; align-items: center; justify-content: center;
  margin: 0 auto 1.5rem; box-shadow: var(--shadow-lg);
}
.about-portrait .initials {
  font-family: var(--font-heading); font-weight: 800;
  font-size: 4.5rem; color: rgba(255,255,255,0.75); z-index: 1;
}
.about-portrait::after {
  content: '';
  position: absolute; bottom: 0; left: 0; right: 0; height: 40%;
  background: linear-gradient(to top, rgba(0,0,0,0.25), transparent);
}
.about-info { display: flex; flex-direction: column; gap: 0.6rem; }
.about-info-item {
  display: flex; align-items: center; gap: 0.875rem;
  padding: 0.75rem 1rem; background: var(--bg-alt);
  border: 1px solid var(--border); border-radius: var(--radius);
  transition: var(--transition);
}
.about-info-item:hover { border-color: var(--primary); background: rgba(30,64,175,0.04); }
.aii-icon {
  width: 34px; height: 34px; border-radius: 8px; flex-shrink: 0;
  background: rgba(30,64,175,0.1); color: var(--primary);
  display: flex; align-items: center; justify-content: center; font-size: 0.85rem;
}
.aii-text { min-width: 0; }
.aii-text .label { font-size: 0.68rem; color: var(--text-light); text-transform: uppercase; letter-spacing: 1px; font-family: var(--font-heading); font-weight: 600; }
.aii-text .value { font-size: 0.82rem; color: var(--text); font-weight: 600; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }

.about-content .lead { font-size: 1.05rem; color: var(--text); line-height: 1.85; margin-bottom: 1.25rem; font-weight: 500; }
.about-content p { font-size: 0.93rem; line-height: 1.85; margin-bottom: 1rem; }
.about-highlights { display: grid; grid-template-columns: 1fr 1fr; gap: 0.875rem; margin: 1.75rem 0; }
.ah-card {
  padding: 1rem 1.25rem; background: var(--bg-alt);
  border: 1px solid var(--border); border-radius: var(--radius);
  border-left: 3px solid var(--primary); transition: var(--transition);
}
.ah-card:hover { border-color: var(--primary); box-shadow: var(--shadow-sm); }
.ah-card h4 { font-size: 0.82rem; color: var(--primary); font-family: var(--font-heading); margin-bottom: 0.15rem; }
.ah-card p  { font-size: 0.78rem; color: var(--text-muted); margin: 0; }
.interests-tags { display: flex; flex-wrap: wrap; gap: 0.5rem; margin-top: 1.5rem; }
.itag {
  display: inline-block; padding: 0.3rem 0.85rem;
  border-radius: 50px; font-size: 0.75rem;
  font-family: var(--font-heading); font-weight: 600;
  transition: var(--transition); cursor: default;
}
.itag-blue   { background: rgba(30,64,175,0.08); color: var(--primary); border: 1px solid rgba(30,64,175,0.2); }
.itag-purple { background: rgba(124,58,237,0.08); color: var(--accent); border: 1px solid rgba(124,58,237,0.2); }
.itag-sky    { background: rgba(14,165,233,0.08); color: var(--secondary); border: 1px solid rgba(14,165,233,0.2); }
.itag-blue:hover   { background: var(--primary); color: #fff; }
.itag-purple:hover { background: var(--accent); color: #fff; }
.itag-sky:hover    { background: var(--secondary); color: #fff; }

/* ══════════════════════════════════════
   TIMELINE (Experience + Education)
══════════════════════════════════════ */
.timeline { position: relative; padding-left: 2.25rem; }
.timeline::before {
  content: ''; position: absolute; left: 17px; top: 0; bottom: 0; width: 2px;
  background: linear-gradient(to bottom, var(--primary), var(--accent), rgba(124,58,237,0.1));
}
.tl-item { position: relative; padding-bottom: 2.25rem; }
.tl-item:last-child { padding-bottom: 0; }
.tl-dot {
  position: absolute; left: -2.25rem; top: 1.25rem;
  width: 38px; height: 38px; border-radius: 50%;
  background: var(--bg-card); border: 2.5px solid var(--primary);
  display: flex; align-items: center; justify-content: center;
  color: var(--primary); font-size: 0.9rem;
  box-shadow: 0 0 0 4px var(--bg);
}
.tl-dot.accent { border-color: var(--accent); color: var(--accent); }
.tl-dot.sky    { border-color: var(--secondary); color: var(--secondary); }
.tl-card {
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 1.5rem 1.75rem;
  transition: var(--transition); box-shadow: var(--shadow-sm);
}
.tl-card:hover { box-shadow: var(--shadow-lg); border-color: rgba(30,64,175,0.25); transform: translateX(4px); }
.tl-top { display: flex; align-items: flex-start; justify-content: space-between; gap: 0.75rem; margin-bottom: 0.4rem; flex-wrap: wrap; }
.tl-title { font-family: var(--font-heading); font-weight: 700; font-size: 1rem; color: var(--text); margin: 0; }
.tl-badge {
  display: inline-flex; align-items: center; gap: 0.3rem;
  padding: 0.2rem 0.7rem; border-radius: 50px; font-size: 0.68rem;
  font-family: var(--font-heading); font-weight: 700; white-space: nowrap; flex-shrink: 0;
}
.badge-present { background: rgba(5,150,105,0.1); color: var(--success); border: 1px solid rgba(5,150,105,0.25); }
.badge-past    { background: rgba(30,64,175,0.08); color: var(--primary); border: 1px solid rgba(30,64,175,0.2); }
.tl-org { font-size: 0.875rem; color: var(--primary); font-weight: 700; margin-bottom: 0.4rem; font-family: var(--font-heading); }
.tl-meta { display: flex; flex-wrap: wrap; gap: 0.875rem; margin-bottom: 0.875rem; }
.tl-meta-item { font-size: 0.78rem; color: var(--text-light); display: flex; align-items: center; gap: 0.35rem; }
.tl-meta-item i { font-size: 0.72rem; color: var(--text-light); }
.tl-desc { font-size: 0.875rem; color: var(--text-muted); line-height: 1.75; margin: 0; }

/* ══════════════════════════════════════
   RESEARCH SECTION
══════════════════════════════════════ */
.research-grid { display: grid; grid-template-columns: repeat(2,1fr); gap: 1.5rem; }
.research-card {
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 2rem; position: relative; overflow: hidden;
  transition: var(--transition); box-shadow: var(--shadow-sm);
}
.research-card::before {
  content: ''; position: absolute; top: 0; left: 0; right: 0; height: 3px;
  background: linear-gradient(90deg, var(--primary), var(--accent));
}
.research-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-5px); border-color: transparent; }
.rc-icon {
  width: 54px; height: 54px; border-radius: var(--radius);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.4rem; margin-bottom: 1.25rem;
}
.rci-blue   { background: rgba(30,64,175,0.1);  color: var(--primary); }
.rci-purple { background: rgba(124,58,237,0.1); color: var(--accent); }
.rci-sky    { background: rgba(14,165,233,0.1); color: var(--secondary); }
.rci-green  { background: rgba(5,150,105,0.1);  color: var(--success); }
.research-card h3 { font-size: 1.05rem; margin-bottom: 0.75rem; }
.research-card p  { font-size: 0.875rem; line-height: 1.78; margin-bottom: 1.25rem; }
.rc-tags { display: flex; flex-wrap: wrap; gap: 0.4rem; }
.rctag {
  display: inline-block; padding: 0.2rem 0.6rem;
  background: var(--bg-alt); border: 1px solid var(--border);
  border-radius: 4px; font-size: 0.68rem;
  font-family: var(--font-heading); font-weight: 600; color: var(--text-muted);
}

/* ══════════════════════════════════════
   PUBLICATIONS
══════════════════════════════════════ */
.pub-card {
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 1.75rem;
  transition: var(--transition); box-shadow: var(--shadow-sm);
  margin-bottom: 1.25rem; position: relative;
}
.pub-card:hover { box-shadow: var(--shadow-lg); border-color: rgba(30,64,175,0.25); }
.pub-card::before {
  content: ''; position: absolute; left: 0; top: 1.5rem; bottom: 1.5rem; width: 3px;
  background: linear-gradient(to bottom, var(--primary), var(--accent));
  border-radius: 0 2px 2px 0;
}
.pub-header { display: flex; align-items: center; gap: 0.75rem; margin-bottom: 0.75rem; flex-wrap: wrap; }
.pub-year {
  display: inline-block; padding: 0.2rem 0.7rem;
  background: var(--primary); color: #fff;
  border-radius: 50px; font-size: 0.68rem; font-family: var(--font-heading); font-weight: 700;
}
.pub-type {
  font-size: 0.7rem; color: var(--text-light); font-family: var(--font-heading);
  font-weight: 600; text-transform: uppercase; letter-spacing: 0.5px;
}
.pub-title {
  font-family: var(--font-heading); font-weight: 700; font-size: 0.95rem;
  color: var(--text); line-height: 1.5; margin-bottom: 0.6rem;
}
.pub-authors { font-size: 0.82rem; color: var(--text-muted); margin-bottom: 0.35rem; line-height: 1.6; }
.pub-authors .me { color: var(--primary); font-weight: 700; text-decoration: underline; text-decoration-style: dotted; }
.pub-journal { font-size: 0.8rem; color: var(--secondary); font-style: italic; margin-bottom: 1.25rem; }
.pub-footer { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 0.75rem; }
.pub-tags { display: flex; gap: 0.4rem; flex-wrap: wrap; }
.ptag {
  display: inline-block; padding: 0.2rem 0.6rem;
  background: rgba(14,165,233,0.08); color: var(--secondary);
  border: 1px solid rgba(14,165,233,0.2); border-radius: 4px;
  font-size: 0.68rem; font-family: var(--font-heading); font-weight: 600;
}

/* ══════════════════════════════════════
   SKILLS SECTION
══════════════════════════════════════ */
.skills-tabs { display: flex; gap: 0.5rem; flex-wrap: wrap; margin-bottom: 2rem; }
.skill-tab {
  padding: 0.5rem 1.2rem; border-radius: 8px;
  font-family: var(--font-heading); font-weight: 600; font-size: 0.78rem;
  border: 2px solid var(--border); color: var(--text-muted);
  transition: var(--transition); background: transparent; display: flex; align-items: center; gap: 0.4rem;
}
.skill-tab:hover,
.skill-tab.active { background: var(--primary); color: #fff; border-color: var(--primary); }
.skill-panel { display: none; }
.skill-panel.active { display: block; animation: panelIn 0.3s ease; }
@keyframes panelIn { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }
.skills-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 0 2.5rem; }
.skill-item { margin-bottom: 1.5rem; }
.skill-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 0.6rem; }
.skill-name { display: flex; align-items: center; gap: 0.5rem; font-family: var(--font-heading); font-weight: 600; font-size: 0.875rem; color: var(--text); }
.skill-name i { font-size: 1rem; }
.skill-pct { font-size: 0.78rem; color: var(--primary); font-family: var(--font-heading); font-weight: 700; }
.skill-bar { height: 7px; background: var(--border); border-radius: 50px; overflow: hidden; }
.skill-fill {
  height: 100%; border-radius: 50px; width: 0;
  transition: width 1.3s cubic-bezier(0.4,0,0.2,1);
}
.sf-primary { background: linear-gradient(90deg, var(--primary), var(--primary-light)); }
.sf-accent  { background: linear-gradient(90deg, var(--accent), var(--accent-light)); }
.sf-sky     { background: linear-gradient(90deg, var(--secondary), #38bdf8); }
.sf-success { background: linear-gradient(90deg, var(--success), #34d399); }

/* Interest Cards (in skills sidebar or separate) */
.interest-grid { display: grid; grid-template-columns: repeat(4,1fr); gap: 1rem; }
.interest-card {
  padding: 1.25rem 1rem; background: var(--bg-card); border: 1px solid var(--border);
  border-radius: var(--radius); text-align: center; transition: var(--transition);
}
.interest-card:hover { border-color: var(--primary); transform: translateY(-3px); box-shadow: var(--shadow); }
.interest-card i   { font-size: 1.6rem; color: var(--primary); display: block; margin-bottom: 0.6rem; }
.interest-card p   { font-size: 0.75rem; color: var(--text-muted); margin: 0; font-family: var(--font-heading); font-weight: 600; line-height: 1.4; }
.interest-card.purple i { color: var(--accent); }
.interest-card.purple:hover { border-color: var(--accent); }
.interest-card.sky i { color: var(--secondary); }
.interest-card.sky:hover { border-color: var(--secondary); }

/* ══════════════════════════════════════
   SEMINARS & CONFERENCES
══════════════════════════════════════ */
.seminar-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
.seminar-card {
  display: flex; align-items: flex-start; gap: 1rem;
  padding: 1.25rem; background: var(--bg-card); border: 1px solid var(--border);
  border-radius: var(--radius); transition: var(--transition);
}
.seminar-card:hover { border-color: var(--secondary); box-shadow: var(--shadow); }
.seminar-icon {
  width: 40px; height: 40px; border-radius: 8px; flex-shrink: 0;
  background: rgba(14,165,233,0.1); display: flex; align-items: center; justify-content: center;
  color: var(--secondary); font-size: 0.9rem;
}
.seminar-text h4 { font-size: 0.85rem; color: var(--text); font-family: var(--font-heading); font-weight: 700; margin-bottom: 0.2rem; line-height: 1.4; }
.seminar-text p  { font-size: 0.75rem; color: var(--text-muted); margin: 0; }

/* ══════════════════════════════════════
   GRANTS & AWARDS
══════════════════════════════════════ */
.grants-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 1.25rem; }
.grant-card {
  display: flex; align-items: flex-start; gap: 1.25rem;
  padding: 1.5rem; background: var(--bg-card); border: 1px solid var(--border);
  border-radius: var(--radius-lg); transition: var(--transition); box-shadow: var(--shadow-sm);
}
.grant-card:hover { border-color: var(--accent); box-shadow: var(--shadow-lg); }
.grant-icon {
  width: 50px; height: 50px; border-radius: var(--radius); flex-shrink: 0;
  background: rgba(124,58,237,0.1); display: flex; align-items: center; justify-content: center;
  color: var(--accent); font-size: 1.25rem;
}
.grant-text h4 { font-size: 0.9rem; color: var(--text); font-family: var(--font-heading); font-weight: 700; margin-bottom: 0.3rem; line-height: 1.45; }
.grant-text p  { font-size: 0.8rem; color: var(--text-muted); margin: 0; }
.grant-period { font-size: 0.72rem; color: var(--accent); font-family: var(--font-heading); font-weight: 700; margin-top: 0.4rem; }

/* ══════════════════════════════════════
   MEMBERSHIPS
══════════════════════════════════════ */
.membership-row { display: grid; grid-template-columns: repeat(3,1fr); gap: 1.25rem; }
.mem-card {
  padding: 1.5rem; background: var(--bg-card); border: 1px solid var(--border);
  border-radius: var(--radius-lg); text-align: center; transition: var(--transition);
}
.mem-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); border-color: var(--primary); }
.mem-abbr {
  display: inline-flex; align-items: center; justify-content: center;
  width: 60px; height: 60px; border-radius: 50%;
  font-family: var(--font-heading); font-weight: 800; font-size: 1rem;
  color: #fff; margin: 0 auto 1rem;
}
.mem-card h4 { font-size: 0.85rem; color: var(--text); font-family: var(--font-heading); font-weight: 700; margin-bottom: 0.25rem; }
.mem-card p  { font-size: 0.78rem; color: var(--text-muted); margin: 0; line-height: 1.5; }

/* ══════════════════════════════════════
   CONTACT SECTION
══════════════════════════════════════ */
.contact-layout { display: grid; grid-template-columns: 1.3fr 1fr; gap: 3rem; }
.contact-form-box {
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 2.5rem; box-shadow: var(--shadow);
}
.form-group { margin-bottom: 1.25rem; }
.form-group label {
  display: block; font-family: var(--font-heading); font-weight: 700;
  font-size: 0.72rem; color: var(--text); margin-bottom: 0.45rem;
  letter-spacing: 0.5px; text-transform: uppercase;
}
.form-group input,
.form-group select,
.form-group textarea {
  width: 100%; padding: 0.875rem 1rem;
  border: 2px solid var(--border); border-radius: var(--radius);
  font-family: var(--font-body); font-size: 0.9rem;
  color: var(--text); background: var(--bg-alt); transition: var(--transition);
}
.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none; border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(30,64,175,0.1); background: var(--bg);
}
.form-group textarea { min-height: 130px; resize: vertical; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
.form-error { font-size: 0.73rem; color: #dc2626; margin-top: 0.3rem; display: none; font-family: var(--font-heading); }
.form-group.error input,
.form-group.error textarea { border-color: #dc2626; }
.form-group.error .form-error { display: block; }
.form-success {
  background: rgba(5,150,105,0.08); color: var(--success);
  border: 1px solid rgba(5,150,105,0.3); border-radius: var(--radius);
  padding: 1rem 1.25rem; margin-top: 1rem; display: none;
  font-size: 0.875rem; font-family: var(--font-heading); font-weight: 600;
}

.contact-info-stack { display: flex; flex-direction: column; gap: 1rem; }
.ci-card {
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 1.25rem;
  display: flex; align-items: flex-start; gap: 1rem; transition: var(--transition);
}
.ci-card:hover { border-color: var(--primary); }
.ci-icon {
  width: 44px; height: 44px; border-radius: 10px; flex-shrink: 0;
  background: rgba(30,64,175,0.1); display: flex; align-items: center; justify-content: center;
  color: var(--primary); font-size: 1.1rem;
}
.ci-text h4 { font-size: 0.72rem; color: var(--text-light); margin-bottom: 0.2rem; font-family: var(--font-heading); font-weight: 700; text-transform: uppercase; letter-spacing: 0.5px; }
.ci-text p, .ci-text a { font-size: 0.875rem; color: var(--text-muted); margin: 0; }
.ci-text a:hover { color: var(--primary); }
.social-row { display: flex; gap: 0.5rem; flex-wrap: wrap; margin-top: 0.75rem; }
.social-btn {
  width: 38px; height: 38px; border-radius: 8px;
  border: 1px solid var(--border); background: var(--bg-alt);
  display: flex; align-items: center; justify-content: center;
  color: var(--text-muted); font-size: 0.9rem; transition: var(--transition);
}
.social-btn:hover { background: var(--primary); color: #fff; border-color: var(--primary); transform: translateY(-2px); }

/* ══════════════════════════════════════
   REFERENCES (collapsible)
══════════════════════════════════════ */
.ref-toggle {
  width: 100%; display: flex; align-items: center; justify-content: space-between;
  padding: 1.25rem 1.5rem; background: var(--bg-card); border: 1px solid var(--border);
  border-radius: var(--radius); font-family: var(--font-heading); font-weight: 700;
  font-size: 0.9rem; color: var(--text); transition: var(--transition); margin-bottom: 0.5rem;
}
.ref-toggle:hover { border-color: var(--primary); color: var(--primary); }
.ref-toggle i { font-size: 0.8rem; transition: transform 0.3s; }
.ref-toggle.open i { transform: rotate(180deg); }
.ref-panel { display: none; grid-template-columns: 1fr 1fr; gap: 1rem; padding-top: 0.25rem; }
.ref-panel.open { display: grid; }
.ref-card {
  padding: 1.25rem; background: var(--bg-card); border: 1px solid var(--border);
  border-radius: var(--radius);
}
.ref-card h4 { font-size: 0.875rem; color: var(--text); font-family: var(--font-heading); font-weight: 700; margin-bottom: 0.25rem; }
.ref-card .ref-inst { font-size: 0.82rem; color: var(--primary); margin-bottom: 0.5rem; font-weight: 600; }
.ref-card p  { font-size: 0.78rem; color: var(--text-muted); margin-bottom: 0.2rem; }
.ref-card a  { font-size: 0.78rem; color: var(--primary); }
.ref-card a:hover { text-decoration: underline; }

/* ══════════════════════════════════════
   FOOTER
══════════════════════════════════════ */
footer {
  background: var(--bg-alt); border-top: 1px solid var(--border);
  padding: 56px 0 28px;
}
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 3rem; margin-bottom: 2.5rem; }
.footer-brand p { font-size: 0.875rem; color: var(--text-muted); max-width: 280px; margin-top: 0.875rem; line-height: 1.75; }
.footer-social { display: flex; gap: 0.5rem; margin-top: 1.25rem; }
.footer-col h4 { font-family: var(--font-heading); font-size: 0.72rem; letter-spacing: 2px; text-transform: uppercase; color: var(--text); margin-bottom: 1rem; }
.footer-links { display: flex; flex-direction: column; gap: 0.6rem; }
.footer-links a { font-size: 0.875rem; color: var(--text-muted); transition: var(--transition); display: flex; align-items: center; gap: 0.4rem; }
.footer-links a:hover { color: var(--primary); padding-left: 4px; }
.footer-links a i { font-size: 0.7rem; }
.footer-bottom {
  border-top: 1px solid var(--border); padding-top: 1.5rem;
  display: flex; justify-content: space-between; align-items: center;
  font-size: 0.8rem; color: var(--text-light); flex-wrap: wrap; gap: 0.75rem;
}
.footer-bottom a { color: var(--primary); }

/* ══════════════════════════════════════
   SCROLL-TO-TOP
══════════════════════════════════════ */
.scroll-top {
  position: fixed; bottom: 2rem; right: 2rem;
  width: 44px; height: 44px; border-radius: 12px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: #fff; display: flex; align-items: center; justify-content: center;
  font-size: 1rem; box-shadow: var(--shadow-lg);
  opacity: 0; transform: translateY(12px);
  pointer-events: none; transition: var(--transition); z-index: 900;
}
.scroll-top.visible { opacity: 1; transform: translateY(0); pointer-events: all; }
.scroll-top:hover { transform: translateY(-3px); box-shadow: var(--shadow-xl); }

/* ══════════════════════════════════════
   ANIMATIONS
══════════════════════════════════════ */
.fade-up {
  opacity: 0; transform: translateY(22px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.fade-up.visible { opacity: 1; transform: translateY(0); }
.fade-in { opacity: 0; transition: opacity 0.65s ease; }
.fade-in.visible { opacity: 1; }

/* ══════════════════════════════════════
   RESPONSIVE
══════════════════════════════════════ */
@media (max-width: 1024px) {
  .hero-inner          { grid-template-columns: 1fr; gap: 2.5rem; }
  .hero-photo-wrap     { order: -1; }
  .profile-photo       { width: 200px; height: 200px; font-size: 3.5rem; }
  .about-grid          { grid-template-columns: 1fr; gap: 2.5rem; }
  .about-photo-col     { position: static; }
  .research-grid       { grid-template-columns: 1fr; }
  .interest-grid       { grid-template-columns: repeat(4,1fr); }
  .contact-layout      { grid-template-columns: 1fr; }
  .footer-grid         { grid-template-columns: 1fr 1fr; gap: 2rem; }
  .grants-grid         { grid-template-columns: 1fr; }
  .membership-row      { grid-template-columns: 1fr 1fr; }
  .seminar-grid        { grid-template-columns: 1fr; }
  .ref-panel.open      { grid-template-columns: 1fr; }
  .skills-grid         { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
  .section-pad { padding: 60px 0; }
  .nav-menu {
    display: none; position: fixed; inset: 0;
    background: var(--bg); flex-direction: column;
    align-items: center; justify-content: center;
    gap: 1.75rem; z-index: 999;
  }
  .nav-menu.open { display: flex; }
  .nav-link { font-size: 1.1rem; padding: 0.5rem 1.5rem; }
  .nav-toggle { display: flex; }
  .hero-stats { gap: 1.5rem; }
  .about-highlights { grid-template-columns: 1fr; }
  .interest-grid { grid-template-columns: repeat(2,1fr); }
  .research-grid { grid-template-columns: 1fr; }
  .seminar-grid  { grid-template-columns: 1fr; }
  .grants-grid   { grid-template-columns: 1fr; }
  .membership-row { grid-template-columns: 1fr; }
  .footer-grid   { grid-template-columns: 1fr; gap: 2rem; }
  .footer-bottom { flex-direction: column; text-align: center; }
  .form-row { grid-template-columns: 1fr; }
}

@media (max-width: 480px) {
  .hero-buttons { flex-direction: column; align-items: flex-start; }
  .interest-grid { grid-template-columns: repeat(2,1fr); }
  .skills-tabs { gap: 0.35rem; }
  .skill-tab { font-size: 0.72rem; padding: 0.4rem 0.875rem; }
}