/* ===== CSS Variables / Design Tokens ===== */
:root {
  --bg-primary: #f5f3ef;
  --bg-secondary: #eae7e0;
  --bg-card: #ffffff;
  --bg-nav: rgba(255, 255, 255, 0.85);
  --text-primary: #1a1a1a;
  --text-secondary: #555555;
  --text-muted: #888888;
  --accent: #2c2c2c;
  --accent-hover: #000000;
  --border-color: #d4d0c8;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
  --shadow-lg: 0 8px 30px rgba(0,0,0,0.1);
  --shadow-nav: 0 2px 20px rgba(0,0,0,0.08);
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-full: 9999px;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --max-width: 780px;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] {
  --bg-primary: #121212;
  --bg-secondary: #1e1e1e;
  --bg-card: #1e1e1e;
  --bg-nav: rgba(30, 30, 30, 0.9);
  --text-primary: #e8e6e3;
  --text-secondary: #a0a0a0;
  --text-muted: #707070;
  --accent: #e0ddd5;
  --accent-hover: #ffffff;
  --border-color: #333333;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.2);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.3);
  --shadow-lg: 0 8px 30px rgba(0,0,0,0.4);
  --shadow-nav: 0 2px 20px rgba(0,0,0,0.4);
}

/* ===== Reset & Base ===== */
*, *::before, *::after {
  margin: 0; padding: 0; box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 100px;
}

body {
  font-family: var(--font-body);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  font-size: 15px;
  transition: background-color var(--transition), color var(--transition);
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color var(--transition);
}
a:hover { color: var(--accent-hover); text-decoration: underline; }

img { max-width: 100%; height: auto; display: block; }

/* ===== Floating Capsule Navbar ===== */
.navbar {
  position: fixed;
  top: 16px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 1000;
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 8px;
  background: var(--bg-nav);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  box-shadow: var(--shadow-nav);
  transition: background var(--transition), border-color var(--transition);
}

.navbar a {
  padding: 8px 16px;
  font-size: 13.5px;
  font-weight: 500;
  color: var(--text-secondary);
  border-radius: var(--radius-full);
  text-decoration: none;
  transition: all var(--transition);
  white-space: nowrap;
}
.navbar a:hover, .navbar a.active {
  background: var(--bg-secondary);
  color: var(--text-primary);
  text-decoration: none;
}

/* Top-right controls */
.top-controls {
  position: fixed;
  top: 20px;
  right: 24px;
  z-index: 1001;
  display: flex;
  align-items: center;
  gap: 10px;
}

.theme-toggle {
  width: 38px; height: 38px;
  border: 1px solid var(--border-color);
  border-radius: 50%;
  background: var(--bg-nav);
  backdrop-filter: blur(10px);
  cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  font-size: 16px;
  color: var(--text-primary);
  transition: all var(--transition);
  box-shadow: var(--shadow-sm);
}
.theme-toggle:hover {
  transform: scale(1.1);
  box-shadow: var(--shadow-md);
}

/* ===== Main Content ===== */
.main-content {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== Hero Section ===== */
.hero {
  padding-top: 100px;
  padding-bottom: 40px;
  text-align: left;
}

.hero-top {
  display: flex;
  align-items: flex-start;
  gap: 24px;
  margin-bottom: 20px;
}

.hero-photo {
  width: 90px; height: 90px;
  border-radius: 50%;
  object-fit: cover;
  border: 3px solid var(--border-color);
  flex-shrink: 0;
}

.hero-info { flex: 1; }

.hero-name {
  font-size: 28px;
  font-weight: 700;
  letter-spacing: -0.5px;
  margin-bottom: 2px;
  line-height: 1.2;
}

.hero-title {
  font-size: 15px;
  color: var(--text-secondary);
  font-weight: 400;
  margin-bottom: 12px;
}

.hero-bio {
  font-size: 14.5px;
  color: var(--text-secondary);
  line-height: 1.75;
  margin-bottom: 20px;
}

.hero-links {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.hero-links a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px; height: 36px;
  border-radius: 50%;
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  font-size: 15px;
  transition: all var(--transition);
  text-decoration: none;
  background: var(--bg-card);
}
.hero-links a:hover {
  background: var(--text-primary);
  color: var(--bg-primary);
  border-color: var(--text-primary);
  transform: translateY(-2px);
  text-decoration: none;
}

.email-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  font-size: 13px;
  font-weight: 500;
  border-radius: var(--radius-full);
  border: 1px solid var(--border-color);
  background: var(--bg-card);
  color: var(--text-primary);
  cursor: pointer;
  transition: all var(--transition);
  text-decoration: none !important;
}
.email-btn:hover {
  background: var(--text-primary);
  color: var(--bg-primary);
  border-color: var(--text-primary);
  text-decoration: none;
}
.email-btn i { font-size: 12px; }

/* ===== Section Styles ===== */
.section {
  padding: 50px 0 30px;
}

.section-title {
  font-size: 24px;
  font-weight: 700;
  letter-spacing: -0.3px;
  margin-bottom: 8px;
  display: inline-block;
  border-bottom: 3px solid var(--accent);
  padding-bottom: 6px;
}

.section-subtitle {
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: 30px;
}

/* ===== Timeline Items ===== */
.timeline-item {
  display: grid;
  grid-template-columns: 160px 1fr;
  gap: 24px;
  padding: 28px 0;
  border-bottom: 1px solid var(--border-color);
  transition: opacity var(--transition);
}
.timeline-item:last-child { border-bottom: none; }

.timeline-date {
  font-size: 13.5px;
  color: var(--text-muted);
  padding-top: 4px;
  font-weight: 400;
}

.timeline-content h3 {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 4px;
  line-height: 1.4;
}

.timeline-content .org {
  font-size: 14px;
  font-weight: 500;
  color: var(--text-primary);
}

.timeline-content .location {
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 10px;
}

.timeline-content p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.7;
}

.timeline-content .grade {
  display: inline-block;
  margin-top: 6px;
  padding: 3px 10px;
  font-size: 12px;
  font-weight: 500;
  background: var(--bg-secondary);
  border-radius: var(--radius-full);
  color: var(--text-secondary);
}

.timeline-links {
  display: flex;
  gap: 10px;
  margin-top: 10px;
  flex-wrap: wrap;
}

.timeline-links a {
  font-size: 13px;
  padding: 5px 12px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  color: var(--text-secondary);
  transition: all var(--transition);
  text-decoration: none;
}
.timeline-links a:hover {
  background: var(--text-primary);
  color: var(--bg-primary);
  border-color: var(--text-primary);
  text-decoration: none;
}

/* ===== Skills Section ===== */
.skills-category {
  margin-bottom: 24px;
}
.skills-category h3 {
  font-size: 14px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--text-muted);
  margin-bottom: 10px;
}

.skill-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.skill-tag {
  padding: 6px 14px;
  font-size: 13px;
  font-weight: 500;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  color: var(--text-secondary);
  transition: all var(--transition);
}
.skill-tag:hover {
  background: var(--text-primary);
  color: var(--bg-primary);
  border-color: var(--text-primary);
  transform: translateY(-1px);
}

/* ===== Awards Grid ===== */
.awards-list {
  list-style: none;
}
.awards-list li {
  padding: 14px 0;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: flex-start;
  gap: 12px;
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.6;
}
.awards-list li:last-child { border-bottom: none; }
.awards-list li::before {
  content: '◆';
  color: var(--text-muted);
  font-size: 8px;
  margin-top: 7px;
  flex-shrink: 0;
}
.awards-list .award-year {
  font-size: 12px;
  color: var(--text-muted);
  margin-left: auto;
  flex-shrink: 0;
  padding-left: 12px;
}

/* ===== Achievements Photo Grid ===== */
.photo-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 16px;
  margin-top: 24px;
}

.photo-card {
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--border-color);
  background: var(--bg-card);
  transition: all var(--transition);
  cursor: default;
}
.photo-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
}
.photo-card img {
  width: 100%;
  height: 160px;
  object-fit: cover;
}
.photo-card .card-body {
  padding: 12px 14px;
}
.photo-card .card-body h4 {
  font-size: 13.5px;
  font-weight: 600;
  margin-bottom: 4px;
  line-height: 1.4;
}
.photo-card .card-body p {
  font-size: 12.5px;
  color: var(--text-muted);
  line-height: 1.5;
}

/* ===== References ===== */
.ref-card {
  padding: 20px 0;
  border-bottom: 1px solid var(--border-color);
}
.ref-card:last-child { border-bottom: none; }
.ref-card h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 2px;
}
.ref-card .ref-role {
  font-size: 13.5px;
  color: var(--text-secondary);
}
.ref-card .ref-dept {
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 8px;
}
.ref-card .ref-links {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}
.ref-card .ref-links a {
  font-size: 13px;
  color: var(--text-secondary);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}
.ref-card .ref-links a:hover { color: var(--accent-hover); }
.ref-card .ref-links a i { font-size: 12px; }

/* ===== Footer ===== */
.footer {
  text-align: center;
  padding: 40px 24px 32px;
  margin-top: 40px;
  border-top: 1px solid var(--border-color);
  font-size: 13px;
  color: var(--text-muted);
}
.footer a { color: var(--text-muted); }
.footer a:hover { color: var(--text-primary); }

/* ===== PDF Floating Button ===== */
.pdf-btn {
  position: fixed;
  bottom: 28px;
  right: 28px;
  z-index: 999;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 18px;
  font-size: 13.5px;
  font-weight: 600;
  background: var(--bg-card);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  box-shadow: var(--shadow-md);
  cursor: pointer;
  transition: all var(--transition);
  text-decoration: none;
  font-family: var(--font-body);
}
.pdf-btn:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
  text-decoration: none;
}
.pdf-btn i { font-size: 15px; }

/* ===== Mobile Nav Toggle ===== */
.nav-toggle {
  display: none;
  position: fixed;
  top: 16px;
  left: 16px;
  z-index: 1002;
  width: 40px; height: 40px;
  border-radius: 50%;
  background: var(--bg-nav);
  backdrop-filter: blur(10px);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
  cursor: pointer;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  color: var(--text-primary);
}

/* ===== Personal Info Grid ===== */
.info-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px 32px;
}
.info-item {
  padding: 8px 0;
}
.info-label {
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--text-muted);
  font-weight: 600;
  margin-bottom: 2px;
}
.info-value {
  font-size: 14px;
  color: var(--text-primary);
}

/* ===== Animations ===== */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}
.animate-in {
  animation: fadeInUp 0.6s ease-out forwards;
  opacity: 0;
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .navbar { display: none; }
  .navbar.mobile-open {
    display: flex;
    flex-direction: column;
    top: 60px;
    left: 16px;
    right: 16px;
    transform: none;
    border-radius: var(--radius-lg);
    padding: 12px;
  }
  .nav-toggle { display: flex; }
  .top-controls { right: 16px; }

  .hero { padding-top: 80px; }
  .hero-top { flex-direction: column; align-items: flex-start; gap: 16px; }
  .hero-photo { width: 72px; height: 72px; }
  .hero-name { font-size: 24px; }

  .timeline-item {
    grid-template-columns: 1fr;
    gap: 4px;
  }
  .timeline-date { padding-top: 0; font-size: 12.5px; }

  .photo-grid { grid-template-columns: repeat(auto-fill, minmax(160px, 1fr)); }
  .info-grid { grid-template-columns: 1fr; }

  .section-title { font-size: 20px; }
  .pdf-btn { bottom: 16px; right: 16px; padding: 8px 14px; font-size: 12.5px; }
}

@media (max-width: 480px) {
  .main-content { padding: 0 16px; }
  .photo-grid { grid-template-columns: 1fr 1fr; gap: 10px; }
  .photo-card img { height: 120px; }
}