@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&display=swap');

:root {
  /* Signature Color Palette - Kondepudi Venkata Durga (Deep Obsidian, Luminous Emerald, Royal Azure, Solar Gold) */
  --bg-page: #06080D;
  --bg-surface: #0B101B;
  --bg-card: #0F1626;
  --bg-card-glass: rgba(15, 22, 38, 0.78);
  --bg-card-hover: rgba(22, 32, 54, 0.9);
  --bg-nav: rgba(6, 8, 13, 0.85);
  --bg-input: rgba(15, 22, 38, 0.85);
  --border: rgba(255, 255, 255, 0.08);
  --border-glow: rgba(16, 185, 129, 0.35);
  --text-primary: #F8FAFC;
  --text-secondary: #94A3B8;
  --text-muted: #64748B;
  --accent: #10B981;          /* Luminous Emerald signature */
  --accent-cyan: #0EA5E9;     /* Cyber Cobalt / Sky */
  --accent-pink: #F59E0B;     /* Solar Amber Gold */
  --accent-gold: #F59E0B;     /* Champagne Gold */
  --accent-soft: rgba(16, 185, 129, 0.12);
  --shadow-card: 0 20px 50px rgba(0, 0, 0, 0.55);
  --shadow-popup: 0 25px 70px rgba(0, 0, 0, 0.75);
  
  /* Gradients */
  --gradient-primary: linear-gradient(135deg, #10B981, #0EA5E9);
  --gradient-warm: linear-gradient(135deg, #F59E0B, #10B981, #0EA5E9);
  --gradient-glow: linear-gradient(135deg, rgba(16,185,129,0.35), rgba(14,165,233,0.35));
  --gradient-gold: linear-gradient(135deg, #F59E0B, #FBBF24, #D97706);
  
  /* Spacing Scale */
  --s-8: 8px;
  --s-16: 16px;
  --s-24: 24px;
  --s-32: 32px;
  --s-48: 48px;
  --s-64: 64px;
  --s-96: 96px;
  --section-pad: 140px;
  
  /* Typography */
  --font-inter: 'Inter', sans-serif;
  
  /* Effects */
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --radius-lg: 24px;
  --radius-md: 12px;
  --radius-sm: 8px;
}

[data-theme="light"] {
  /* Color Palette - Executive Muted Platinum Slate (Soft & Easy on the Eyes, Zero Pure White Glare) */
  --bg-page: #EAEFF5;
  --bg-surface: #DFE5ED;
  --bg-card: #F3F6FA;
  --bg-card-glass: rgba(235, 241, 248, 0.88);
  --bg-card-hover: rgba(228, 235, 244, 0.96);
  --bg-nav: rgba(234, 239, 245, 0.92);
  --bg-input: #DDE3EC;
  --border: rgba(30, 41, 59, 0.12);
  --border-glow: rgba(5, 150, 105, 0.35);
  --text-primary: #1E293B;
  --text-secondary: #475569;
  --text-muted: #64748B;
  --accent: #059669;          /* Deep Emerald */
  --accent-cyan: #0284C7;     /* Ocean Cobalt */
  --accent-pink: #D97706;     /* Warm Amber */
  --accent-gold: #D97706;     /* Warm Amber */
  --accent-soft: rgba(5, 150, 105, 0.12);
  --shadow-card: 0 10px 30px rgba(15, 23, 42, 0.08), 0 2px 6px rgba(15, 23, 42, 0.04);
  --shadow-popup: 0 20px 50px rgba(15, 23, 42, 0.15);
  
  --gradient-primary: linear-gradient(135deg, #059669, #0284C7);
  --gradient-warm: linear-gradient(135deg, #D97706, #059669, #0284C7);
  --gradient-glow: linear-gradient(135deg, rgba(5,150,105,0.2), rgba(2,132,199,0.2));
  --gradient-gold: linear-gradient(135deg, #D97706, #F59E0B, #EA580C);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  -webkit-font-smoothing: antialiased;
}

html {
  scroll-behavior: smooth;
  background-color: var(--bg-page);
  font-size: 18px;
}

#canvas-bg {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -1;
  pointer-events: none;
  opacity: 0.7;
}

body {
  font-family: var(--font-inter);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
}

/* Layout */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--s-32);
}

section {
  padding: var(--section-pad) 0;
  position: relative;
}

/* Section Gradient Dividers */
section::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 60%;
  height: 1px;
  background: var(--gradient-primary);
  opacity: 0.2;
}

section:last-of-type::after {
  display: none;
}

/* Navbar - Glassmorphic */
nav {
  position: fixed;
  top: 24px;
  left: 50%;
  transform: translateX(-50%) translateY(-20px);
  width: min(1200px, 90%);
  background: var(--bg-nav);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid rgba(16, 185, 129, 0.15);
  border-radius: 100px;
  padding: 12px 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  z-index: 1000;
  opacity: 0;
  transition: opacity 0.8s ease, transform 0.8s cubic-bezier(0.2, 0.8, 0.2, 1);
}

nav.active {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

.nav-logo {
  font-weight: 800;
  font-size: 20px;
  letter-spacing: -0.02em;
  background: var(--gradient-warm);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  cursor: pointer;
  transition: var(--transition);
}


.nav-actions {
  display: flex;
  gap: var(--s-16);
  align-items: center;
}

.nav-cta-btn {
  padding: 8px 18px;
  font-size: 13px;
}

.nav-logo:hover {
  filter: brightness(1.2);
}

.nav-links {
  display: flex;
  gap: var(--s-24);
  list-style: none;
}

.nav-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 13px;
  font-weight: 500;
  transition: var(--transition);
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--gradient-primary);
  transition: width 0.3s ease;
  border-radius: 2px;
}

.nav-links a:hover {
  color: var(--text-primary);
}

.nav-links a:hover::after {
  width: 100%;
}

/* Theme Toggle Button */
.theme-toggle-btn {
  background: var(--accent-soft);
  border: 1px solid var(--border-glow);
  color: var(--text-primary);
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 16px;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  overflow: hidden;
  flex-shrink: 0;
}

.theme-toggle-btn:hover {
  transform: rotate(20deg) scale(1.1);
  border-color: var(--accent-cyan);
  box-shadow: 0 0 15px var(--border-glow);
}

[data-theme="light"] .theme-toggle-btn .sun-icon {
  display: none;
}
[data-theme="light"] .theme-toggle-btn .moon-icon {
  display: inline-block;
}
:root:not([data-theme="light"]) .theme-toggle-btn .moon-icon {
  display: none;
}
:root:not([data-theme="light"]) .theme-toggle-btn .sun-icon {
  display: inline-block;
}

/* Hero Section */
.hero {
  min-height: 90vh;
  display: flex;
  align-items: center;
  padding-top: 160px;
}

.hero-layout {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: var(--s-64);
  align-items: center;
}

.hero-content {
  max-width: 800px;
}

/* Gradient Hero Heading */
h1 {
  font-size: clamp(56px, 10vw, 96px);
  line-height: 1.05;
  font-weight: 800;
  letter-spacing: -0.05em;
  margin-bottom: var(--s-32);
  background: var(--gradient-warm);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-sub {
  font-size: 20px;
  color: var(--text-secondary);
  max-width: 700px;
  margin-bottom: var(--s-48);
  line-height: 1.7;
}

/* Glowing Hero Visual */
.hero-visual {
  position: relative;
  animation: float 6s ease-in-out infinite;
}

.hero-visual::before {
  content: '';
  position: absolute;
  inset: -3px;
  border-radius: calc(var(--radius-lg) + 3px);
  background: var(--gradient-primary);
  opacity: 0.5;
  z-index: -1;
  filter: blur(20px);
  animation: glowPulse 4s ease-in-out infinite;
}

@keyframes glowPulse {
  0%, 100% { opacity: 0.3; }
  50% { opacity: 0.6; }
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-20px); }
}

.hero-visual img {
  width: 100%;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-glow);
  box-shadow: 0 40px 80px rgba(0, 0, 0, 0.5);
}

/* Badge */
.badge {
  display: inline-flex;
  align-items: center;
  padding: 6px 16px;
  background: rgba(16, 185, 129, 0.08);
  border: 1px solid rgba(16, 185, 129, 0.2);
  border-radius: 100px;
  font-size: 13px;
  color: var(--accent-cyan);
  margin-bottom: var(--s-32);
  font-family: 'Inter', monospace;
  gap: 8px;
  font-weight: 500;
}

.badge span {
  color: var(--accent);
}

.pulse {
  width: 8px;
  height: 8px;
  background: #10B981;
  border-radius: 50%;
  box-shadow: 0 0 0 rgba(16, 185, 129, 0.4);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% { box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.4); }
  70% { box-shadow: 0 0 0 10px rgba(16, 185, 129, 0); }
  100% { box-shadow: 0 0 0 0 rgba(16, 185, 129, 0); }
}

/* Buttons - Gradient Primary */
.btn-group {
  display: flex;
  gap: var(--s-16);
}

.btn {
  padding: 14px 28px;
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-weight: 600;
  text-decoration: none;
  transition: var(--transition);
  display: inline-block;
  position: relative;
}

.btn-primary {
  background: var(--gradient-primary);
  color: #FFFFFF;
  box-shadow: 0 4px 20px rgba(16, 185, 129, 0.3);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(16, 185, 129, 0.5);
}

.btn-secondary {
  background: transparent;
  color: var(--text-primary);
  border: 1px solid rgba(16, 185, 129, 0.3);
}

.btn-secondary:hover {
  background: rgba(16, 185, 129, 0.08);
  border-color: var(--accent);
  transform: translateY(-2px);
}

/* Infinite Tech Marquee */
.tech-strip {
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: var(--s-24) 0;
  background: var(--bg-card-glass);
  overflow: hidden;
  white-space: nowrap;
  position: relative;
}

.tech-strip::before,
.tech-strip::after {
  content: "";
  position: absolute;
  top: 0;
  width: 150px;
  height: 100%;
  z-index: 2;
}

.tech-strip::before {
  left: 0;
  background: linear-gradient(to right, var(--bg-page), transparent);
}

.tech-strip::after {
  right: 0;
  background: linear-gradient(to left, var(--bg-page), transparent);
}

.tech-scroll {
  display: inline-flex;
  animation: marquee 40s linear infinite;
}

.tech-item {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-secondary);
  margin-right: var(--s-64);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  display: flex;
  align-items: center;
  gap: 8px;
  transition: color 0.3s ease;
}

.tech-item::before {
  content: '◆';
  font-size: 8px;
  color: var(--accent);
}

@keyframes marquee {
  0% { transform: translateX(0); }
  100% { transform: translateX(-50%); }
}

/* Section Header */
.section-header {
  margin-bottom: var(--s-64);
  position: relative;
}

/* Custom CSS 3D Floating Object */
.css-3d-wrapper {
  position: absolute;
  right: 2%;
  top: -20px;
  width: 100px;
  height: 100px;
  perspective: 800px;
  pointer-events: none;
  z-index: 0;
}

.core-3d {
  width: 100%;
  height: 100%;
  position: relative;
  transform-style: preserve-3d;
  animation: spin3d 12s linear infinite;
}

.core-ring {
  position: absolute;
  inset: 5px;
  border: 2px solid rgba(14, 165, 233, 0.3);
  border-radius: 50%;
  transform-style: preserve-3d;
}

.core-ring:nth-child(1) { transform: rotateX(0deg) rotateY(0deg); border-color: rgba(16, 185, 129, 0.5); }
.core-ring:nth-child(2) { transform: rotateX(60deg) rotateY(30deg); border-color: rgba(14, 165, 233, 0.5); }
.core-ring:nth-child(3) { transform: rotateX(120deg) rotateY(60deg); border-color: rgba(245, 158, 11, 0.5); }

.core-center {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 20px;
  height: 20px;
  background: var(--gradient-primary);
  border-radius: 50%;
  transform: translate(-50%, -50%);
  box-shadow: 0 0 15px rgba(14, 165, 233, 0.6);
}

@keyframes spin3d {
  0% { transform: rotateX(0deg) rotateY(0deg) rotateZ(0deg); }
  100% { transform: rotateX(360deg) rotateY(360deg) rotateZ(360deg); }
}

.section-label {
  color: var(--accent-cyan);
  font-size: 13px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  margin-bottom: var(--s-16);
  display: block;
}

h2 {
  font-size: clamp(32px, 5vw, 48px);
  font-weight: 700;
  letter-spacing: -0.03em;
}

/* Project Cards - Glassmorphic */
.project-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--s-32);
}

.project-card {
  background: var(--bg-card-glass);
  backdrop-filter: blur(12px);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 0;
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  overflow: visible;
  display: flex;
  flex-direction: column;
  transform-style: preserve-3d;
}

/* Gradient border glow on hover */
.project-card::before {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: var(--radius-lg);
  padding: 1px;
  background: var(--gradient-primary);
  -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  opacity: 0;
  transition: opacity 0.4s ease;
  z-index: 1;
  pointer-events: none;
}

.project-card:hover::before {
  opacity: 1;
}

.project-card:hover {
  transform: translateY(-6px) scale(1.02);
  box-shadow: 0 25px 70px rgba(16, 185, 129, 0.2), 0 0 45px rgba(16, 185, 129, 0.12);
  z-index: 10;
}

.project-image {
  width: 100%;
  aspect-ratio: 16 / 10;
  background: rgba(0, 0, 0, 0.4);
  overflow: hidden;
  border-bottom: 1px solid var(--border);
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}

.project-image img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  padding: 8px;
  transition: transform 0.8s cubic-bezier(0.2, 0.8, 0.2, 1);
}

.project-card:hover .project-image img {
  transform: scale(1.08);
}

.project-info {
  padding: var(--s-48);
  display: flex;
  flex-direction: column;
  flex-grow: 1;
  transform: translateZ(30px);
  overflow: visible;
}

.project-card h3 {
  font-size: 24px;
  margin-bottom: var(--s-16);
  display: flex;
  align-items: center;
  gap: var(--s-16);
}

.project-card p {
  color: var(--text-secondary);
  margin-bottom: var(--s-32);
  flex-grow: 1;
  line-height: 1.7;
}

/* Tags - Enhanced */
.tag-group {
  display: flex;
  flex-wrap: wrap;
  gap: var(--s-8);
  margin-top: auto;
}

.tag {
  font-size: 12px;
  background: rgba(16, 185, 129, 0.08);
  padding: 5px 12px;
  border-radius: 100px;
  color: var(--accent-cyan);
  border: 1px solid rgba(16, 185, 129, 0.15);
  font-weight: 500;
  transition: var(--transition);
}

.tag:hover {
  background: rgba(16, 185, 129, 0.15);
  border-color: var(--accent);
}

/* Award Tags */
.award-tag {
  background: rgba(255, 215, 0, 0.08);
  color: var(--accent-gold);
  border-color: rgba(255, 215, 0, 0.2);
}

.award-tag:hover {
  background: rgba(255, 215, 0, 0.15);
  border-color: var(--accent-gold);
}

/* Expandable Flex Grid Gallery */
.expandable-grid {
  display: flex;
  gap: var(--s-24);
  height: 520px;
  width: 100%;
}

.expandable-card {
  flex: 1;
  background: var(--bg-card-glass);
  backdrop-filter: blur(12px);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: flex 0.6s cubic-bezier(0.2, 0.8, 0.2, 1), border-color 0.4s ease, box-shadow 0.4s ease, transform 0.4s ease;
  position: relative;
  cursor: pointer;
  transform-style: preserve-3d;
}

.expandable-card:hover {
  flex: 3.5;
  border-color: var(--accent);
  box-shadow: 0 25px 70px rgba(16, 185, 129, 0.25), 0 0 45px rgba(16, 185, 129, 0.12);
  transform: scale(1.01);
  z-index: 10;
}

.expandable-card::before {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: var(--radius-lg);
  padding: 1px;
  background: var(--gradient-primary);
  -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  opacity: 0;
  transition: opacity 0.6s ease;
  z-index: 1;
  pointer-events: none;
}

.expandable-card:hover::before {
  opacity: 1;
}

/* Collapsed state view inside the card */
.ec-collapsed {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  padding: 0;
  transition: opacity 0.3s ease;
  transition-delay: 0.2s; /* remain visible when unhovered */
  overflow: hidden;
  width: 100%;
  height: 100%;
}

.expandable-card:hover .ec-collapsed {
  opacity: 0;
  pointer-events: none;
  transition-delay: 0s;
}

.ec-collapsed .ec-thumb {
  width: 100%;
  height: 220px;
  background: rgba(0, 0, 0, 0.4);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--s-16);
}

.ec-collapsed .ec-thumb img {
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.ec-collapsed .ec-preview-info {
  padding: var(--s-24);
  display: flex;
  flex-direction: column;
  flex-grow: 1;
  justify-content: space-between;
}

.ec-collapsed .ec-preview-info h4 {
  font-size: 20px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: var(--s-8);
  display: flex;
  align-items: center;
  gap: 8px;
}

.ec-collapsed .ec-preview-info p {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.5;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
  margin-bottom: var(--s-16);
}

/* Expanded state detailed view */
.ec-expanded {
  position: absolute;
  inset: 0;
  display: grid;
  grid-template-columns: 1fr 1.3fr;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.4s ease;
  transition-delay: 0s;
  overflow: hidden;
  width: 100%;
  height: 100%;
}

.expandable-card:hover .ec-expanded {
  opacity: 1;
  pointer-events: auto;
  transition-delay: 0.3s; /* beautifully reveal detailed contents */
}

.ec-expanded .ec-image {
  height: 100%;
  border-right: 1px solid var(--border);
  background: rgba(0, 0, 0, 0.4);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--s-16);
}

.ec-expanded .ec-image img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  transition: transform 0.6s cubic-bezier(0.2, 0.8, 0.2, 1);
}

.expandable-card:hover .ec-expanded .ec-image img {
  transform: scale(1.05);
}

.ec-expanded .ec-info {
  padding: var(--s-32) var(--s-48);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  overflow-y: auto;
  transform: translateZ(30px);
}

.ec-expanded .ec-info h3 {
  font-size: 28px;
  margin-bottom: var(--s-8);
  display: flex;
  align-items: center;
  gap: var(--s-16);
}

.ec-expanded .ec-info p {
  color: var(--text-secondary);
  font-size: 15px;
  line-height: 1.6;
  margin-bottom: var(--s-24);
}

/* Skill Progress Bars */
.skill-bars {
  display: flex;
  flex-direction: column;
  gap: var(--s-24);
  margin-top: var(--s-32);
}

.skill-bar-item {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.skill-bar-label {
  display: flex;
  justify-content: space-between;
  font-size: 14px;
  color: var(--text-secondary);
  font-weight: 500;
}

.skill-bar-label span:last-child {
  color: var(--accent-cyan);
  font-size: 12px;
}

.skill-bar-track {
  width: 100%;
  height: 6px;
  background: rgba(255, 255, 255, 0.05);
  border-radius: 100px;
  overflow: hidden;
}

.skill-bar-fill {
  height: 100%;
  background: var(--gradient-primary);
  border-radius: 100px;
  width: 0%;
  transition: width 1.5s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: 0 0 10px rgba(16, 185, 129, 0.4);
}

.skill-bar-fill.active {
  /* Width set via inline style */
}

/* Expertise Lists - Enhanced */
.expertise-list {
  list-style: none;
  margin-top: var(--s-24);
}

.expertise-list li {
  font-size: 14px;
  color: var(--text-secondary);
  padding: 8px 0;
  display: flex;
  align-items: flex-start;
  gap: 12px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.03);
  transition: var(--transition);
}

.expertise-list li:last-child {
  border-bottom: none;
}

.expertise-list li:hover {
  color: var(--text-primary);
  padding-left: 8px;
}

.expertise-list li::before {
  content: '→';
  color: var(--accent-cyan);
  font-weight: bold;
  flex-shrink: 0;
}

/* Architecture Showcase - Glassmorphic */
.arch-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--s-32);
}

.arch-card {
  background: var(--bg-card-glass);
  backdrop-filter: blur(12px);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--s-32);
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  display: flex;
  flex-direction: column;
  position: relative;
  transform-style: preserve-3d;
}

.arch-card::before {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: var(--radius-lg);
  padding: 1px;
  background: var(--gradient-primary);
  -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  opacity: 0;
  transition: opacity 0.4s ease;
  pointer-events: none;
}

.arch-card:hover::before {
  opacity: 0.7;
}

.arch-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 20px 40px rgba(16, 185, 129, 0.1);
}

.arch-visual {
  width: 100%;
  aspect-ratio: 16/9;
  border: 1px solid var(--border);
  margin-bottom: var(--s-24);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.arch-visual img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  background: #000;
}

.arch-card h4 {
  font-size: 20px;
  margin-bottom: var(--s-8);
  color: var(--text-primary);
}

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

/* Capabilities */
.cap-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: var(--s-16);
}

/* --- Compact trigger pill --- */
.cap-item {
  background: var(--bg-card-glass);
  border: 1px solid var(--border);
  padding: 18px var(--s-24);
  border-radius: var(--radius-md);
  transition: all 0.45s cubic-bezier(0.2, 0.8, 0.2, 1);
  position: relative;
  cursor: pointer;
  min-height: 90px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  overflow: visible;
}

.cap-item::before {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: var(--radius-md);
  background: var(--gradient-primary);
  opacity: 0;
  transition: opacity 0.4s ease;
  z-index: 0;
  padding: 1px;
  -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
}

.cap-item:hover {
  border-color: var(--accent);
  background: rgba(16, 185, 129, 0.1);
  box-shadow: 0 8px 30px rgba(16, 185, 129, 0.2);
  transform: translateY(-3px);
}

.cap-item:hover::before {
  opacity: 1;
}

.cap-header {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  gap: 3px;
}

.cap-item h4 {
  font-size: 15px;
  font-weight: 600;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 0;
}

.cap-item .cap-sub {
  font-size: 12px;
  color: var(--text-secondary);
}

/* --- Global Floating popup card (JS-positioned) --- */
.cap-popup {
  position: fixed;
  width: 360px;
  background: var(--bg-card-glass);
  border: 1px solid rgba(16, 185, 129, 0.4);
  border-radius: var(--radius-lg);
  box-shadow: 0 30px 80px rgba(0, 0, 0, 0.6), 0 0 40px rgba(16, 185, 129, 0.15);
  backdrop-filter: blur(20px);
  overflow: hidden;
  opacity: 0;
  pointer-events: none;
  transform: translateY(16px) scale(0.94);
  transition: opacity 0.4s cubic-bezier(0.2, 0.8, 0.2, 1),
              transform 0.4s cubic-bezier(0.2, 0.8, 0.2, 1);
  z-index: 9999;
}

.cap-popup.is-visible {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0) scale(1);
}

.cap-popup-image {
  width: 100%;
  height: 180px;
  overflow: hidden;
  background: rgba(0,0,0,0.4);
  border-bottom: 1px solid rgba(16, 185, 129, 0.2);
  display: flex;
  align-items: center;
  justify-content: center;
}

.cap-popup-image img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  padding: 12px;
  transition: transform 0.6s cubic-bezier(0.2, 0.8, 0.2, 1);
}

.cap-popup.is-visible .cap-popup-image img {
  transform: scale(1.06);
}

.cap-popup-body {
  padding: 20px 22px 18px;
}

.cap-popup-body h4 {
  font-size: 17px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.cap-popup-body p {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.55;
  margin-bottom: 14px;
}

.cap-popup-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.cap-popup-tags .tag {
  padding: 3px 10px;
  font-size: 10px;
}

/* ═══════════════════════════════════════════════════════════════
   AWARDS & RECOGNITIONS SECTION
   ═══════════════════════════════════════════════════════════════ */

.awards-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--s-32);
  margin-bottom: var(--s-48);
}

.award-card {
  background: var(--bg-card-glass);
  backdrop-filter: blur(12px);
  border: 1px solid rgba(255, 215, 0, 0.1);
  border-radius: var(--radius-lg);
  padding: 0;
  overflow: hidden;
  transition: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  transform-style: preserve-3d;
}

.award-card::before {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: var(--radius-lg);
  padding: 1px;
  background: var(--gradient-gold);
  -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  opacity: 0;
  transition: opacity 0.4s ease;
  z-index: 1;
  pointer-events: none;
}

.award-card:hover::before {
  opacity: 1;
}

.award-card:hover {
  transform: translateY(-8px) scale(1.02);
  box-shadow: 
    0 25px 60px rgba(255, 215, 0, 0.12),
    0 0 40px rgba(255, 165, 0, 0.08),
    0 0 80px rgba(16, 185, 129, 0.06);
  border-color: rgba(255, 215, 0, 0.3);
}

.award-trophy {
  position: absolute;
  top: 16px;
  right: 16px;
  font-size: 32px;
  z-index: 2;
  filter: drop-shadow(0 0 10px rgba(255, 215, 0, 0.5));
  animation: trophyFloat 3s ease-in-out infinite;
}

@keyframes trophyFloat {
  0%, 100% { transform: translateY(0) rotate(0deg); }
  25% { transform: translateY(-5px) rotate(5deg); }
  75% { transform: translateY(-3px) rotate(-3deg); }
}

.award-image {
  width: 100%;
  height: 220px;
  overflow: hidden;
  position: relative;
  background: rgba(0, 0, 0, 0.3);
  border-bottom: 1px solid rgba(255, 215, 0, 0.1);
}

.award-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.8s cubic-bezier(0.2, 0.8, 0.2, 1);
  filter: brightness(0.9);
}

.award-card:hover .award-image img {
  transform: scale(1.08);
  filter: brightness(1);
}

.award-year {
  position: absolute;
  bottom: 12px;
  left: 12px;
  background: rgba(0, 0, 0, 0.7);
  backdrop-filter: blur(10px);
  padding: 4px 14px;
  border-radius: 100px;
  font-size: 13px;
  font-weight: 700;
  color: var(--accent-gold);
  border: 1px solid rgba(255, 215, 0, 0.2);
  letter-spacing: 0.05em;
}

.award-info {
  padding: var(--s-24) var(--s-32) var(--s-32);
}

.award-info h3 {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: var(--s-8);
  background: var(--gradient-gold);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.award-info p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: var(--s-16);
}

/* ═══════════════════════════════════════════════════════════════
   PUBLICATIONS & RESEARCH SECTION (Distinct Research Paper Boxes)
   ═══════════════════════════════════════════════════════════════ */

.publications-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--s-32);
  margin-bottom: var(--s-48);
}

.pub-box {
  background: var(--bg-card-glass);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid rgba(16, 185, 129, 0.18);
  border-radius: var(--radius-lg);
  padding: var(--s-32);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  position: relative;
  overflow: hidden;
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
}

.pub-box::before {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: var(--radius-lg);
  padding: 1px;
  background: linear-gradient(135deg, rgba(16, 185, 129, 0.5), rgba(14, 165, 233, 0.35), transparent 70%);
  -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  opacity: 0;
  transition: opacity 0.4s ease;
  pointer-events: none;
}

.pub-box:hover::before {
  opacity: 1;
}

.pub-box:hover {
  transform: translateY(-8px);
  border-color: rgba(16, 185, 129, 0.4);
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.6), 0 0 35px rgba(16, 185, 129, 0.2);
}

.pub-box-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--s-20);
}

.pub-box-meta {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.pub-type-tag {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--accent);
  background: var(--accent-soft);
  border: 1px solid rgba(16, 185, 129, 0.28);
  padding: 4px 10px;
  border-radius: 100px;
}

.pub-type-tag.ieee-tag {
  color: var(--accent-cyan);
  background: rgba(14, 165, 233, 0.1);
  border-color: rgba(14, 165, 233, 0.3);
}

.pub-date-tag {
  font-size: 11px;
  color: var(--text-muted);
  font-weight: 500;
}

.pub-icon-badge {
  font-size: 26px;
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: rgba(15, 22, 38, 0.6);
  border: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
  flex-shrink: 0;
}

.pub-box-content {
  flex: 1;
  display: flex;
  flex-direction: column;
}

.pub-box-title {
  font-size: 18px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--text-primary);
  margin-bottom: var(--s-12);
  transition: color 0.3s ease;
}

.pub-box:hover .pub-box-title {
  color: #FFFFFF;
}

.pub-box-desc {
  font-size: 13.5px;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: var(--s-16);
}

.pub-tag-highlight {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
  margin-bottom: var(--s-16);
}

.pub-chip {
  font-size: 11px;
  font-weight: 600;
  color: var(--text-muted);
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border);
  padding: 3px 10px;
  border-radius: 6px;
}

.pub-chip.metric-chip {
  color: var(--accent);
  background: var(--accent-soft);
  border-color: rgba(16, 185, 129, 0.3);
  font-weight: 700;
}

.pub-authors-box {
  background: rgba(6, 8, 13, 0.45);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 10px 14px;
  margin-bottom: var(--s-16);
}

.pub-authors-label {
  display: block;
  font-size: 10px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-muted);
  margin-bottom: 4px;
}

.pub-authors-list {
  font-size: 12.5px;
  color: var(--text-secondary);
  line-height: 1.5;
}

.author-highlight {
  color: var(--accent);
  font-weight: 700;
  text-decoration: underline;
  text-decoration-color: rgba(16, 185, 129, 0.4);
  text-underline-offset: 2px;
}

.pub-venue-badge {
  font-size: 11px;
  color: var(--accent-cyan);
  background: rgba(14, 165, 233, 0.08);
  border: 1px solid rgba(14, 165, 233, 0.2);
  padding: 6px 10px;
  border-radius: 6px;
  margin-bottom: var(--s-16);
  line-height: 1.4;
  font-weight: 500;
}

.pub-box-footer {
  margin-top: auto;
  padding-top: var(--s-16);
  border-top: 1px solid var(--border);
}

.pub-action-btn {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: 12px 18px;
  border-radius: var(--radius-sm);
  background: var(--gradient-primary);
  color: #FFFFFF;
  text-decoration: none;
  font-size: 13.5px;
  font-weight: 600;
  letter-spacing: 0.02em;
  transition: all 0.3s ease;
  box-shadow: 0 4px 15px rgba(16, 185, 129, 0.25);
}

.pub-action-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(16, 185, 129, 0.45);
  filter: brightness(1.1);
  color: #FFFFFF;
}

.pub-action-btn.ieee-btn {
  background: linear-gradient(135deg, #0EA5E9, #10B981);
}

.pub-btn-arrow {
  font-size: 16px;
  transition: transform 0.25s ease;
}

.pub-action-btn:hover .pub-btn-arrow {
  transform: translate(3px, -3px);
}

/* ═══════════════════════════════════════════════════════════════
   RESUME SECTION
   ═══════════════════════════════════════════════════════════════ */

.resume-wrapper {
  display: grid;
  grid-template-columns: 1.5fr 1fr;
  gap: var(--s-48);
  align-items: start;
}

.resume-stat-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--s-16);
  margin-bottom: var(--s-48);
}

.resume-stat {
  background: var(--bg-card-glass);
  backdrop-filter: blur(12px);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: var(--s-24);
  text-align: center;
  transition: all 0.4s ease;
}

.resume-stat:hover {
  border-color: var(--accent);
  transform: translateY(-4px);
  box-shadow: 0 15px 30px rgba(16, 185, 129, 0.15);
}

.resume-stat-number {
  font-size: 32px;
  font-weight: 800;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
  margin-bottom: 6px;
}

.resume-stat-label {
  font-size: 12px;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-weight: 500;
}

/* Timeline */
.resume-timeline {
  position: relative;
  padding-left: var(--s-32);
}

.resume-timeline::before {
  content: '';
  position: absolute;
  left: 7px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--gradient-primary);
  opacity: 0.3;
}

.timeline-item {
  position: relative;
  margin-bottom: var(--s-32);
}

.timeline-dot {
  position: absolute;
  left: calc(-1 * var(--s-32) + 2px);
  top: 6px;
  width: 12px;
  height: 12px;
  background: var(--gradient-primary);
  border-radius: 50%;
  box-shadow: 0 0 10px rgba(16, 185, 129, 0.5);
}

.timeline-content {
  padding-bottom: var(--s-16);
}

.timeline-date {
  font-size: 12px;
  color: var(--accent-cyan);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 4px;
}

.timeline-content h4 {
  font-size: 18px;
  color: var(--text-primary);
  margin-bottom: 4px;
}

.timeline-content p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* Resume Download Card */
.resume-download-area {
  position: sticky;
  top: 120px;
}

.resume-preview-card {
  background: var(--bg-card-glass);
  backdrop-filter: blur(12px);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--s-48);
  text-align: center;
  transition: all 0.4s ease;
  position: relative;
  overflow: hidden;
}

.resume-preview-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 200px;
  height: 200px;
  background: radial-gradient(circle, rgba(16, 185, 129, 0.12), transparent 70%);
  pointer-events: none;
}

.resume-preview-card:hover {
  border-color: rgba(16, 185, 129, 0.3);
  box-shadow: 0 20px 40px rgba(16, 185, 129, 0.1);
}

.resume-doc-icon {
  width: 64px;
  height: 64px;
  margin: 0 auto var(--s-24);
  color: var(--accent);
  opacity: 0.8;
}

.resume-doc-icon svg {
  width: 100%;
  height: 100%;
}

.resume-preview-card h4 {
  font-size: 16px;
  color: var(--text-primary);
  margin-bottom: var(--s-8);
  word-break: break-all;
}

.resume-preview-card p {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* ═══════════════════════════════════════════════════════════════
   ANIMATED WALKING ROBOT GUIDE COMPANION
   ═══════════════════════════════════════════════════════════════ */

.robot-guide {
  position: fixed;
  bottom: 24px;
  left: 0;
  z-index: 999;
  display: flex;
  flex-direction: column;
  align-items: center;
  pointer-events: auto;
  user-select: none;
  transform: translate3d(60px, 0, 0);
  transition: transform 0.12s linear;
  will-change: transform;
}

/* Minimized / Floating Orb State */
.robot-guide.is-minimized {
  transform: translate3d(calc(100vw - 72px), 0, 0) !important;
  bottom: 20px !important;
}

.robot-guide.is-minimized .robot-speech {
  display: none !important;
}

.robot-guide.is-minimized .robot-avatar-wrapper {
  width: 48px;
  height: 48px;
  background: var(--bg-card-glass);
  border: 2px solid var(--accent);
  border-radius: 50%;
  box-shadow: 0 0 20px rgba(16, 185, 129, 0.4), var(--shadow-card);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  animation: orbPulse 2.5s infinite;
  padding: 0;
  overflow: hidden;
}

.robot-guide.is-minimized .robot-gif-img {
  width: 42px;
  height: 42px;
  object-fit: cover;
  border-radius: 50%;
}

.robot-guide.is-minimized .robot-action-controls {
  display: none !important;
}

@keyframes orbPulse {
  0%, 100% { box-shadow: 0 0 12px rgba(16, 185, 129, 0.35); }
  50% { box-shadow: 0 0 26px rgba(16, 185, 129, 0.7); }
}

/* Avatar Holographic Capsule Wrapper */
.robot-avatar-wrapper {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  background: radial-gradient(circle at 50% 60%, rgba(16, 185, 129, 0.18), rgba(6, 8, 13, 0.45));
  border: 1.5px solid var(--border-glow);
  border-radius: 24px;
  padding: 6px;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.6), 0 0 20px rgba(16, 185, 129, 0.25);
  transition: all 0.3s ease;
}

.robot-avatar-wrapper:hover {
  border-color: var(--accent);
  box-shadow: 0 12px 35px rgba(0, 0, 0, 0.7), 0 0 25px rgba(16, 185, 129, 0.45);
}

.robot-gif-img {
  width: 90px;
  height: 90px;
  object-fit: contain;
  border-radius: 16px;
  display: block;
  transition: opacity 0.25s ease;
  filter: drop-shadow(0 4px 12px rgba(0, 0, 0, 0.5));
}

/* Walking floating step animation */
.robot-guide.is-walking .robot-avatar-wrapper {
  animation: walkingBob 0.6s ease-in-out infinite alternate;
}

@keyframes walkingBob {
  from { transform: translateY(0); }
  to { transform: translateY(-4px); }
}

/* Action Controls Pill */
.robot-action-controls {
  position: absolute;
  bottom: -6px;
  display: flex;
  gap: 4px;
  background: var(--bg-card-glass);
  backdrop-filter: blur(10px);
  border: 1px solid var(--border-glow);
  border-radius: 100px;
  padding: 2px 6px;
  opacity: 0;
  transform: translateY(4px);
  transition: all 0.25s ease;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.4);
  z-index: 2;
}

.robot-guide:hover .robot-action-controls {
  opacity: 1;
  transform: translateY(0);
}

.robot-ctrl-btn {
  background: transparent;
  border: none;
  color: var(--text-secondary);
  font-size: 11px;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.2s ease;
}

.robot-ctrl-btn:hover {
  color: var(--accent);
  background: var(--accent-soft);
  transform: scale(1.15);
}

/* Speech Bubble - Screen-Safe Floating Card */
.robot-speech {
  position: fixed;
  bottom: 110px;
  left: 0;
  background: var(--bg-card-glass);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--border-glow);
  border-radius: var(--radius-md);
  padding: 14px 18px;
  color: var(--text-primary);
  width: 310px;
  max-width: 330px;
  line-height: 1.55;
  opacity: 0;
  pointer-events: none;
  transform: translate3d(60px, 0, 0);
  transition: opacity 0.35s cubic-bezier(0.2, 0.8, 0.2, 1);
  box-shadow: var(--shadow-popup), 0 0 25px rgba(16, 185, 129, 0.2);
  z-index: 9998;
}

.robot-speech.active {
  opacity: 1;
  pointer-events: auto;
}

.robot-speech-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 6px;
}

.robot-badge {
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--accent);
  text-transform: uppercase;
  background: var(--accent-soft);
  padding: 2px 8px;
  border-radius: 100px;
  border: 1px solid rgba(16, 185, 129, 0.3);
  display: inline-flex;
  align-items: center;
  gap: 5px;
}

.robot-status-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 8px var(--accent);
  animation: radarPing 2s infinite;
}

@keyframes radarPing {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.4; transform: scale(1.3); }
}

.robot-speech-close {
  background: transparent;
  border: none;
  color: var(--text-muted);
  font-size: 18px;
  line-height: 1;
  cursor: pointer;
  padding: 0 4px;
  transition: color 0.2s ease;
}

.robot-speech-close:hover {
  color: var(--accent-pink);
}

#robotText {
  font-size: 13px;
  color: var(--text-primary);
  margin: 0;
  min-height: 38px;
  word-break: break-word;
}

/* Mobile & Tablet Responsiveness */

/* ═══════════════════════════════════════════════════════════════
   MOBILE NAVIGATION BUTTON & DRAWER OVERLAY
   ═══════════════════════════════════════════════════════════════ */

.mobile-menu-btn {
  display: none;
  background: var(--accent-soft);
  border: 1px solid var(--border-glow);
  color: var(--text-primary);
  width: 34px;
  height: 34px;
  border-radius: 50%;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 3.5px;
  cursor: pointer;
  padding: 0;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  flex-shrink: 0;
  z-index: 1001;
}

.mobile-menu-btn:hover,
.mobile-menu-btn:focus-visible {
  background: rgba(16, 185, 129, 0.2);
  border-color: var(--accent);
  box-shadow: 0 0 12px var(--border-glow);
}

.mobile-menu-btn .hamburger-line {
  display: block;
  width: 14px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: all 0.3s ease;
}

.mobile-menu-btn.is-active .hamburger-line:nth-child(1) {
  transform: translateY(5.5px) rotate(45deg);
}

.mobile-menu-btn.is-active .hamburger-line:nth-child(2) {
  opacity: 0;
  transform: scaleX(0);
}

.mobile-menu-btn.is-active .hamburger-line:nth-child(3) {
  transform: translateY(-5.5px) rotate(-45deg);
}

/* Mobile Navigation Drawer & Backdrop */
.mobile-nav-drawer {
  position: fixed;
  inset: 0;
  z-index: 99999;
  visibility: hidden;
  pointer-events: none;
  transition: visibility 0.3s ease;
}

.mobile-nav-drawer.is-open {
  visibility: visible;
  pointer-events: auto;
}

.mobile-nav-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(4, 6, 10, 0.8);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  opacity: 0;
  transition: opacity 0.3s ease;
}

.mobile-nav-drawer.is-open .mobile-nav-backdrop {
  opacity: 1;
}

.mobile-nav-sheet {
  position: absolute;
  top: 14px;
  left: 12px;
  right: 12px;
  background: var(--bg-card);
  border: 1px solid var(--border-glow);
  border-radius: 22px;
  padding: 18px 18px 22px;
  box-shadow: var(--shadow-popup), 0 0 40px rgba(16, 185, 129, 0.22);
  transform: translateY(-16px) scale(0.97);
  opacity: 0;
  transition: transform 0.3s cubic-bezier(0.2, 0.8, 0.2, 1), opacity 0.3s ease;
  max-height: calc(100vh - 28px);
  overflow-y: auto;
}

[data-theme="light"] .mobile-nav-sheet {
  background: var(--bg-card);
  border-color: rgba(5, 150, 105, 0.3);
  box-shadow: 0 25px 60px rgba(15, 23, 42, 0.2), 0 0 25px rgba(5, 150, 105, 0.15);
}

.mobile-nav-drawer.is-open .mobile-nav-sheet {
  transform: translateY(0) scale(1);
  opacity: 1;
}

.mobile-nav-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 10px;
}

.mobile-nav-title {
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  display: flex;
  align-items: center;
  gap: 6px;
}

.mobile-nav-close {
  background: var(--accent-soft);
  border: 1px solid var(--border-glow);
  color: var(--text-primary);
  width: 28px;
  height: 28px;
  border-radius: 50%;
  font-size: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  line-height: 1;
  transition: all 0.2s ease;
}

.mobile-nav-close:hover {
  background: rgba(239, 68, 68, 0.18);
  border-color: #ef4444;
  color: #ef4444;
}

.mobile-nav-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 3px;
}

.mobile-nav-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 14px;
  border-radius: 12px;
  font-size: 14.5px;
  font-weight: 600;
  color: var(--text-primary);
  text-decoration: none;
  transition: all 0.2s ease;
}

.mobile-nav-icon {
  font-size: 16px;
}

.mobile-nav-item:hover,
.mobile-nav-item:active {
  background: var(--accent-soft);
  color: var(--accent);
  transform: translateX(4px);
}

.mobile-nav-footer {
  margin-top: 14px;
  padding-top: 12px;
  border-top: 1px solid var(--border);
}

.mobile-nav-cta {
  width: 100%;
  text-align: center;
  display: block;
  padding: 10px 16px !important;
  font-size: 13.5px !important;
  font-weight: 600 !important;
  border-radius: 100px !important;
}

@media (max-width: 768px) {
  .robot-guide {
    bottom: 16px !important;
    left: auto !important;
    right: 16px !important;
    transform: none !important;
  }
  .robot-gif-img {
    width: 68px;
    height: 76px;
  }
  .robot-speech {
    right: 0 !important;
    left: auto !important;
    width: 280px;
    max-width: calc(100vw - 32px);
  }
  .robot-speech::after {
    right: 30px !important;
    left: auto !important;
  }
}

/* Scroll to Top Button */
.scroll-top-btn {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 48px;
  height: 48px;
  background: var(--bg-card-glass);
  backdrop-filter: blur(15px);
  border: 1px solid rgba(16, 185, 129, 0.3);
  border-radius: 50%;
  color: var(--accent-cyan);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  transform: translateY(20px);
  transition: all 0.4s cubic-bezier(0.2, 0.8, 0.2, 1);
  z-index: 998;
}

.scroll-top-btn svg {
  width: 20px;
  height: 20px;
}

.scroll-top-btn.visible {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}

.scroll-top-btn:hover {
  background: rgba(16, 185, 129, 0.2);
  border-color: var(--accent);
  transform: translateY(-4px);
  box-shadow: 0 8px 25px rgba(16, 185, 129, 0.3);
}

/* Contact CTA - Glassmorphic */
.cta-box {
  background: var(--bg-card-glass);
  backdrop-filter: blur(12px);
  border: 1px solid rgba(16, 185, 129, 0.15);
  border-radius: var(--radius-lg);
  padding: var(--s-96) var(--s-32);
  text-align: center;
  position: relative;
  overflow: hidden;
  transform-style: preserve-3d;
}

.cta-box::before {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 300px;
  height: 300px;
  background: radial-gradient(circle, rgba(16, 185, 129, 0.15), transparent 70%);
  pointer-events: none;
}

.cta-box h2 {
  margin-bottom: var(--s-32);
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  transform: translateZ(30px);
}

.cta-box .btn {
  transform: translateZ(40px);
}

/* Footer */
footer {
  padding: var(--s-64) 0;
  border-top: 1px solid var(--border);
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.footer-copy {
  color: var(--text-secondary);
  font-size: 14px;
}

.footer-links {
  display: flex;
  gap: var(--s-24);
}

.footer-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 14px;
  transition: var(--transition);
}

.footer-links a:hover {
  color: var(--accent-cyan);
}

/* Animations - Enhanced Staggered Reveal */
.reveal {
  opacity: 0;
  transform: translateY(30px) scale(0.98);
  transition: opacity 1s cubic-bezier(0.2, 0.8, 0.2, 1), transform 1s cubic-bezier(0.2, 0.8, 0.2, 1);
}

.reveal.active {
  opacity: 1;
  transform: translateY(0) scale(1);
}

.reveal-delay-1 { transition-delay: 0.1s; }
.reveal-delay-2 { transition-delay: 0.2s; }
.reveal-delay-3 { transition-delay: 0.3s; }
.reveal-delay-4 { transition-delay: 0.4s; }

/* ═══════════════════════════════════════════════════════════════
   RESPONSIVE LAYOUTS & MOBILE EXCELLENCE
   ═══════════════════════════════════════════════════════════════ */

html, body {
  overflow-x: hidden !important;
  max-width: 100vw !important;
  width: 100% !important;
}

@media (max-width: 1100px) {
  .publications-grid { grid-template-columns: repeat(2, 1fr) !important; gap: 20px !important; }
  .awards-grid { grid-template-columns: 1fr; }
  .resume-wrapper { grid-template-columns: 1fr; }
  .resume-stat-grid { grid-template-columns: repeat(2, 1fr); }
  .resume-download-area { position: static; }
}

@media (max-width: 992px) {
  .project-grid { grid-template-columns: 1fr !important; }
  .project-card { grid-column: span 1 !important; }
  .arch-grid { grid-template-columns: 1fr !important; }
  h1 { font-size: clamp(34px, 7vw, 56px) !important; }
  
  .hero-layout,
  .project-card .hero-layout {
    grid-template-columns: 1fr !important;
    gap: var(--s-24);
  }
  
  .project-card .hero-layout .project-image {
    order: -1;
    border-right: none !important;
    border-left: none !important;
    border-bottom: 1px solid var(--border);
    height: 240px;
  }
  
  .project-card .project-info {
    padding: var(--s-24) !important;
  }

  .expandable-grid {
    display: flex !important;
    flex-direction: column !important;
    height: auto !important;
    gap: 20px !important;
  }

  .expandable-card {
    flex: none !important;
    height: auto !important;
    min-height: 0 !important;
    overflow: hidden !important;
  }

  .expandable-card .ec-collapsed {
    display: none !important;
  }

  .expandable-card .ec-expanded {
    display: flex !important;
    position: static !important;
    opacity: 1 !important;
    pointer-events: auto !important;
    flex-direction: column !important;
    width: 100% !important;
    height: auto !important;
  }

  .expandable-card .ec-image {
    width: 100% !important;
    height: 220px !important;
    border-right: none !important;
    border-bottom: 1px solid var(--border) !important;
  }

  .expandable-card .ec-info {
    padding: 22px 20px !important;
  }

  .publication-card {
    flex-direction: column;
    text-align: center;
    gap: var(--s-16);
  }
}

/* Official Post Verification Link */
.award-verify-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-top: var(--s-16);
  font-size: 12px;
  font-weight: 600;
  color: var(--accent);
  text-decoration: none;
  background: var(--accent-soft);
  border: 1px solid var(--border-glow);
  padding: 6px 14px;
  border-radius: 100px;
  transition: all 0.25s ease;
}

.award-verify-link:hover {
  background: rgba(16, 185, 129, 0.25);
  border-color: var(--accent);
  color: #FFFFFF;
  transform: translateY(-2px);
  box-shadow: 0 4px 15px rgba(16, 185, 129, 0.35);
}

/* Mobile Screens (Phone & Small Tablets) */
@media (max-width: 768px) {
  .container {
    padding: 0 16px !important;
    width: 100% !important;
    max-width: 100% !important;
  }

  nav { 
    width: calc(100% - 20px) !important;
    padding: 8px 12px !important;
    top: 8px !important;
    border-radius: 100px !important;
    gap: 8px !important;
    display: flex !important;
    justify-content: space-between !important;
    align-items: center !important;
  }
  
  .nav-links { display: none !important; }
  .nav-badge-hide-mobile { display: none !important; }
  
  .nav-logo {
    font-size: clamp(12px, 3.2vw, 13.5px) !important;
    font-weight: 800 !important;
    white-space: nowrap !important;
    overflow: hidden !important;
    text-overflow: ellipsis !important;
    max-width: 48% !important;
    letter-spacing: -0.01em !important;
    flex-shrink: 1 !important;
  }

  .nav-actions {
    display: flex !important;
    align-items: center !important;
    gap: 6px !important;
    flex-shrink: 0 !important;
  }

  .theme-toggle-btn {
    width: 32px !important;
    height: 32px !important;
    font-size: 13px !important;
  }

  .nav-cta-btn {
    padding: 6px 12px !important;
    font-size: 12px !important;
    border-radius: 100px !important;
    white-space: nowrap !important;
  }

  .mobile-menu-btn {
    display: flex !important;
  }
  
  section { padding: 56px 0 !important; }
  .section-header { margin-bottom: 28px !important; }
  .section-header h2 { font-size: clamp(26px, 7vw, 36px) !important; }
  .css-3d-wrapper { display: none !important; } /* Hide floating 3D rings on mobile to avoid header overlap */

  .hero { 
    padding-top: 90px !important; 
    min-height: auto !important; 
    text-align: center;
  }

  .hero-content {
    text-align: center;
  }

  .hero-content .badge {
    margin: 0 auto 16px auto !important;
    font-size: 11px !important;
    padding: 5px 12px !important;
  }

  h1 {
    font-size: clamp(28px, 8vw, 42px) !important;
    line-height: 1.18 !important;
    margin-bottom: 14px !important;
  }

  .hero-sub {
    font-size: 14px !important;
    line-height: 1.6 !important;
    margin-bottom: 22px !important;
  }

  .btn-group {
    flex-direction: column !important;
    width: 100% !important;
    gap: 10px !important;
  }

  .btn-group .btn {
    width: 100% !important;
    justify-content: center !important;
    text-align: center;
    padding: 12px 20px !important;
    font-size: 14px !important;
  }

  .hero-visual {
    margin-top: 16px;
  }

  .cap-grid-wrapper {
    grid-template-columns: 1fr !important;
    gap: 10px !important;
  }

  .cap-popup {
    max-width: calc(100vw - 28px) !important;
    width: auto !important;
    left: 14px !important;
    right: 14px !important;
  }

  .project-card .project-info {
    padding: 18px 14px !important;
  }

  .project-card .project-info h3 {
    font-size: 20px !important;
  }

  .awards-grid { 
    grid-template-columns: 1fr !important; 
    gap: 20px !important; 
  }
  
  .award-image {
    height: 190px !important;
  }
  
  .award-info {
    padding: 18px 16px !important;
  }
  
  .award-info h3 {
    font-size: 18px !important;
  }

  .resume-stat-grid { 
    grid-template-columns: repeat(2, 1fr) !important; 
    gap: 10px !important; 
  }

  .resume-stat {
    padding: 14px 10px !important;
  }

  .resume-stat-number {
    font-size: clamp(20px, 5.5vw, 28px) !important;
  }

  .resume-stat-label {
    font-size: 10px !important;
  }

  .resume-preview-card {
    padding: 24px 16px !important;
  }

  .cta-box { 
    padding: 36px 16px !important; 
    text-align: center; 
  }

  .cta-box h2 {
    font-size: clamp(24px, 6.5vw, 32px) !important;
    margin-bottom: 16px !important;
  }

  .contact-grid { grid-template-columns: 1fr !important; }

  /* Mobile Publications - Single Column Clean Card Grid */
  .publications-grid {
    grid-template-columns: 1fr !important;
    gap: 16px !important;
  }

  .pub-box {
    padding: 20px 16px !important;
    border-radius: 18px !important;
  }

  .pub-box-title {
    font-size: 16px !important;
  }

  .pub-box-desc {
    font-size: 13px !important;
  }

  .pub-authors-box {
    padding: 8px 12px !important;
  }

  .pub-authors-list {
    font-size: 12px !important;
  }

  /* Mobile Walking Robot Guide: walks smoothly across bottom */
  .robot-guide {
    position: fixed !important;
    bottom: 12px !important;
    left: 0 !important;
    right: auto !important;
    z-index: 9999 !important;
    pointer-events: auto !important;
  }

  .robot-avatar-wrapper {
    width: 58px !important;
    height: 58px !important;
    padding: 3px !important;
    border-radius: 18px !important;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.6), 0 0 15px rgba(16, 185, 129, 0.4) !important;
  }

  .robot-gif-img {
    width: 52px !important;
    height: 52px !important;
    object-fit: contain !important;
    border-radius: 14px !important;
  }

  .robot-action-controls {
    display: none !important;
  }

  /* Compact responsive speech bubble card on mobile - stable full-width toast */
  .robot-speech {
    position: fixed !important;
    bottom: 84px !important;
    left: 14px !important;
    right: 14px !important;
    width: auto !important;
    max-width: none !important;
    min-width: 0 !important;
    transform: none !important;
    padding: 12px 16px !important;
    font-size: 13px !important;
    line-height: 1.5 !important;
    border-radius: 16px !important;
    box-shadow: 0 12px 35px rgba(0, 0, 0, 0.8), 0 0 20px rgba(16, 185, 129, 0.3) !important;
    z-index: 10001 !important;
    white-space: normal !important;
    word-break: normal !important;
    transition: opacity 0.3s ease !important;
  }

  .robot-speech p {
    font-size: 13px !important;
    line-height: 1.5 !important;
    margin: 0 !important;
    white-space: normal !important;
    word-break: normal !important;
    display: block !important;
  }

  .robot-speech.anchor-left,
  .robot-speech.anchor-right,
  .robot-speech.anchor-center {
    left: 14px !important;
    right: 14px !important;
    transform: none !important;
  }

  .robot-speech::after {
    display: none !important;
  }

  .footer-inner {
    flex-direction: column;
    gap: var(--s-16);
    text-align: center;
  }
}