:root {
  --primary: #1a1f2e;
  --secondary: #2c5282;
  --accent: #4299e1;
  --background: #f7fafc;
  --text: #2d3748;
  --card-bg: #ffffff;
  --nav-height: 10vh;
}
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  line-height: 1.6;
  color: var(--text);
  background: var(--background);
  overflow-x: hidden;
}
.loading-screen {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 1000;
  transition: opacity 0.5s;
}
.loader {
  width: 40px;
  height: 40px;
  border: 3px solid rgba(255, 255, 255, 0.1);
  border-radius: 50%;
  border-top-color: var(--accent);
  animation: spin 1s infinite ease-in-out;
  box-shadow: 0 0 20px rgba(66, 153, 225, 0.2);
}
@keyframes spin {
  to { transform: rotate(360deg); }
}
nav {
  position: fixed;
  top: 0;
  width: 100%;
  background: rgba(255, 255, 255, 0.98);
  backdrop-filter: blur(10px);
  z-index: 100;
  box-shadow: 0 2px 20px rgba(0, 0, 0, 0.05);
}
.nav-content {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}
.nav-name {
  font-weight: 700;
  font-size: 1.3rem;
  color: var(--primary);
  letter-spacing: -0.02em;
}
@media (max-width: 576px) {
  .hero-content h1 { font-size: 2rem; }
  .hero-content p { font-size: 0.9rem; padding-top: 5%; }
  .nav-name { display: none; }
  .cta-button { padding: 0.6rem 1.2rem; }
}
.nav-links {
  display: flex;
  gap: 2rem;
}
.nav-links a {
  color: var(--text);
  text-decoration: none;
  font-weight: 500;
  font-size: 1rem;
  padding: 0.5rem 0;
  transition: all 0.3s;
}
.nav-links a:hover {
  color: var(--accent);
  transform: translateY(-2px);
}
.hero-section {
  min-height: 100vh;
  display: flex;
  padding-top: calc(var(--nav-height));
  align-items: center;
  position: relative;
  background: linear-gradient(135deg, var(--primary) 0%, #1f2d4e 100%);
  overflow: hidden;
}
.hero-section::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none'%3E%3Cg fill='%23ffffff' fill-opacity='0.02'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
  opacity: 0.5;
}
.particle-container {
  position: absolute;
  width: 100%;
  height: 100%;
  pointer-events: none;
}
.particle {
  position: absolute;
  width: 2.5px;
  height: 2.5px;
  background: rgba(255, 250, 255, 0.9);
  border-radius: 50%;
  opacity: 0.7;
  box-shadow: 0 0 20px rgba(165, 100, 255, 0.85);
}

@keyframes float {
  0% { transform: translateY(120vh) translateX(-50px); opacity: 0.1; }
  25% { opacity: 0.5; }
  50% { opacity: 1; }
  75% { opacity: 0.35; }
  100% { transform: translateY(-150px) translateX(50px); opacity: 0.2; }
}
.hero-content {
  max-width: 1200px;
  margin: 0 auto;
  padding: 4rem 2rem;
  color: white;
  z-index: 1;
  position: relative;
}
.hero-content h1 {
  font-size: 3.5rem;
  line-height: 1.2;
  margin-bottom: 1.8rem;
  background: linear-gradient(135deg, #ffffff 0%, var(--accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  font-weight: 800;
}
.hero-content p {
  font-size: 1.2rem;
  max-width: 700px;
  margin-bottom: 1rem;
  opacity: 0.9;
}
.cta-button {
  display: inline-block;
  margin-top: 1rem;
  padding: 0.75rem 1.5rem;
  background: var(--accent);
  color: #fff;
  text-decoration: none;
  border-radius: 4px;
  transition: background 0.3s;
}
.cta-button:hover { background: var(--primary); }
.interests-section {
  padding: 6rem 2rem;
  background: white;
}
.section-title {
  text-align: center;
  margin-bottom: 4rem;
  font-size: 2.5rem;
  color: var(--primary);
}
.interests-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  max-width: 1200px;
  margin: 0 auto;
}
.interest-card {
  background: var(--card-bg);
  padding: 2rem;
  border-radius: 8px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.05);
  transition: transform 0.3s;
  border: 1px solid rgba(0, 0, 0, 0.05);
}
.papers-section {
  padding: 6rem 2rem;
  background: var(--background);
  min-height: calc(100vh - var(--nav-height) * 3);
}
.publications-tabs {
  display: flex;
  justify-content: center;
  gap: 1rem;
  margin-bottom: 2rem;
}
.publications-tabs button {
  padding: 0.75rem 1.5rem;
  border: none;
  background: var(--accent);
  color: white;
  border-radius: 4px;
  cursor: pointer;
  transition: background 0.3s;
}
.publications-tabs button.active {
  background: var(--primary);
}
.publications-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  gap: 2rem;
  max-width: 1200px;
  margin: 0 auto;
}
.paper-card {
  background: hsla(0, 0%, 90%, 0.90);
  padding: 2rem;
  border-radius: 8px;
  box-shadow: 0 6px 20px rgba(25, 5, 30, 0.2);
  cursor: pointer;
  transition: transform 0.3s;
  border: 0.6px solid rgba(50, 100, 198, 0.3);
}
.paper-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 5px 12px rgba(100, 100, 160, 0.4);
}
.paper-card h3 {
  color: var(--primary);
  margin-bottom: 1rem;
  font-size: 1.2rem;
}
.paper-category {
  display: inline-block;
  padding: 0.3rem 1rem;
  background: var(--accent);
  color: white;
  border-radius: 20px;
  font-size: 0.9rem;
  margin-bottom: 1rem;
}
.pdf-viewer-section {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.9);
  z-index: 1000;
  display: flex;
  justify-content: center;
  align-items: center;
  transition: opacity 0.3s;
}
.pdf-viewer-section.hidden {
  opacity: 0;
  pointer-events: none;
}
.pdf-viewer-container {
  width: 100%;
  height: 100%;
  background: var(--background);
  border-radius: 8px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  border: 1px solid rgba(0, 0, 0, 0.1);
}
.pdf-viewer-header {
  padding: 1rem;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.pdf-viewer-header button:not(:first-child) {
  box-shadow: 0 0 5px rgba(0, 255, 0, 0.1);
  border: solid 2px  rgba(0, 255, 0, 0.3);
  color: rgba(0, 255, 0, 0.55);
  background-color: transparent;
  padding:0.5rem 1rem;
  border-radius: 10px;
  margin-left: 1rem;
}

.pdf-viewer-header button:not(:last-child) {
  margin-right: 1rem;
  box-shadow: 0 0 5px rgba(255, 0, 0, 0.1);
  border: solid 2px rgba(255, 0, 0, 0.55);
  color: rgba(255, 0, 0, 0.75);
  background-color: transparent;
  padding:0.5rem 1rem;
  border-radius: 10px;
}

.pdf-viewer-header button:not(:first-child):hover {
  box-shadow: 0 0 5px rgba(0, 255, 0, 7);
  border: solid 2px  rgba(0, 255, 0, 1);
  color: rgba(0, 255, 0, 1);
  background-color: transparent;
  backdrop-filter: blur(10px);
}

.pdf-viewer-header button:not(:last-child):hover {
  box-shadow: 0 0 5pxrgba(255, 0, 0, 7);
  border: solid 2px rgba(255, 0, 0, 1);
  color: rgba(255, 0, 0, 1);
  backdrop-filter: blur(10px);
  background-color: transparent;
}

.pdf-viewer-header button {
  background: none;
  border: none;
  color: white;
  border:
  cursor: pointer;
  font-size: 1.2rem;
  transition: color 0.3s;
}
.pdf-viewer-header button:hover {
  color: var(--accent);
}
#pdf-viewer {
  flex: 1;
  overflow: auto;
}
.pdf-navigation {
  position: fixed;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  background: rgba(0, 0, 0, 0.8);
  backdrop-filter: blur(10px);
  border-radius: 20px;
  padding: 0.5rem;
  display: flex;
  gap: 0.5rem;
  z-index: 2000;
}
.pdf-nav-button {
  background: none;
  border: none;
  color: white;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.pdf-nav-button:hover {
  background: rgba(255, 255, 255, 0.2);
}
.pdf-page-number {
  font-size: 1rem;
}
#pdf-display {
  flex: 1;
  overflow: auto;
  background: #f5f5f5;
  padding: 0.2rem;
}
---webkit-scrollbar {
  width: 8px;
}
::-webkit-scrollbar-track {
  background: #f1f1f1;
}
::-webkit-scrollbar-thumb {
  background: #888;
  border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
  background: #555;
}
.pdf-page {
  background: white;
  margin: 1rem auto;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  max-width: 100%;
  display: flex;
  justify-content: center;
  position: relative;
}
.pdf-page canvas {
  max-width: 100%;
  height: auto;
}
.loading,
.error {
  text-align: center;
  padding: 2rem;
  color: var(--text);
  font-size: 1.2rem;
}
footer {
  background: var(--primary);
  color: white;
  padding: 4rem 3rem;
}
.footer-content {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 3rem;
}
.footer-section h3 {
  margin-bottom: 1.5rem;
  font-size: 1.2rem;
}
.contact-info {
  opacity: 0.9;
  font-size: 0.95rem;
}
footer a {
  color: var(--accent);
  text-decoration: none;
  transition: color 0.3s;
}
footer a:hover { color: white; }
.search-interface {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background: rgba(255, 255, 255, 0.98);
  backdrop-filter: blur(10px);
  padding: 1rem 2rem;
  transform: translateY(-100%);
  transition: transform 0.4s;
  z-index: 90;
  box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
}
.search-interface.active { transform: translateY(0); }
.search-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  gap: 1rem;
  align-items: center;
}
.search-input {
  flex: 1;
  padding: 1rem;
  border: none;
  background: rgba(0, 0, 0, 0.05);
  border-radius: 8px;
  font-size: 1rem;
  transition: all 0.3s;
}
.search-input:focus { background: rgba(0, 0, 0, 0.08); outline: none; }
.search-filters { display: flex; gap: 0.5rem; }
.filter-chip {
  padding: 0.5rem 1rem;
  background: var(--accent);
  color: white;
  border-radius: 20px;
  font-size: 0.9rem;
  cursor: pointer;
  transition: all 0.3s;
}
.filter-chip:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(66, 153, 225, 0.2);
}
.reading-progress {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: rgba(0, 0, 0, 0.1);
  z-index: 2001;
}
.reading-progress-bar {
  height: 100%;
  background: var(--accent);
  width: 0;
  transition: width 0.3s;
}
.annotation-toolbar {
  position: fixed;
  left: 50%;
  bottom: 2rem;
  transform: translateX(-50%);
  background: rgba(0, 0, 0, 0.8);
  backdrop-filter: blur(10px);
  padding: 0.75rem;
  border-radius: 12px;
  display: flex;
  gap: 0.5rem;
  z-index: 2002;
}
.annotation-tool {
  padding: 0.5rem;
  color: white;
  border-radius: 6px;
  cursor: pointer;
  transition: all 0.3s;
}
.annotation-tool:hover { background: rgba(255, 255, 255, 0.2); }
.annotation-tool.active { background: var(--accent); }
.pdf-annotation {
  position: absolute;
  z-index: 3;
  pointer-events: all;
}
.highlight-layer {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: all;
  z-index: 2;
}
.highlight {
  position: absolute;
  background: rgba(255, 236, 61, 0.3);
  border: 1px solid rgba(255, 236, 61, 0.5);
  pointer-events: none;
  transition: all 0.2s;
}

@media (max-width: 768px) {
  .nav-content { padding: 1rem; }
  .nav-links { display: flex; justify-content: space-around; align-items: center; width: 100% !important; padding-left: 7.5%; padding-right: 7.5%; }
  .nav-links a { justify-content: space-around; align-items: center; font-size: 1rem; }
  .hero-content { padding: 1rem 1rem 3rem 1rem; }
  .hero-content h1 { font-size: 2.8rem; margin-top: -3rem; }
  .section-title { font-size: clamp(1.75rem, 5vw, 2rem); }
  .interests-grid, .publications-grid { grid-template-columns: 1fr; }
  .publications-tabs { flex-direction: column; align-items: center; }
  .publications-tabs button { width: 100%; }
  .footer-content { grid-template-columns: 1fr; }
}
@media (max-width: 992px) {
  .nav-links { gap: 1rem; }
  .nav-links a { font-size: 0.9rem; }
  .hero-content h1 { font-size: clamp(2rem, 3vw, 4vw, 5vw); }
  .hero-content p { font-size: clamp(1rem, 2vw, 3vw); }
}
@media (max-width: 1200px) {
  .nav-content, .hero-content, .interests-grid, .publications-grid, .footer-content, .search-container {
  max-width: 960px;
}
}
@media (max-width: 576px) {
  .nav-name { font-size: 1.1rem; }
  .nav-links a { font-size: 0.95rem; text-transform: uppercase; font-weight: 600; };
  .section-title { font-size: 1.75rem; }
  .hero-content h1 { font-size: 2.2rem; }
  .hero-content p { font-size: 1rem; }
  .cta-button { padding: 0.7rem 1.4rem; }
}

@media (max-width: 576px) and (max-height:900px) {
  .hero-content h1 { margin-top: -6rem; }
}