/* ==========================================================================
   PORTFOLIO STYLESHEET - ARJUN RAJ A
   Aspiring VLSI Engineer & M.Tech VLSI Design Student
   Modern, Semiconductor & Hardware Oriented, Dark/Light Mode
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Outfit:wght@300;400;500;600;700;800&family=Plus+Jakarta+Sans:wght@400;500;600;700&family=JetBrains+Mono:wght@400;600&display=swap');

/* --- Root Variables & Theme Tokens --- */
:root {
  /* Color Palette - Dark Theme (Default) */
  --bg-primary: #070c18;
  --bg-secondary: #0d1527;
  --bg-tertiary: #17223b;
  --bg-card: rgba(13, 21, 39, 0.78);
  --bg-card-hover: rgba(23, 34, 59, 0.95);
  --bg-glass: rgba(7, 12, 24, 0.75);
  --border-color: rgba(255, 255, 255, 0.08);
  --border-hover: rgba(56, 189, 248, 0.45);

  /* Text Colors */
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --text-inverse: #070c18;

  /* Brand Accents - Silicon & Semiconductor Tones */
  --accent-cyan: #38bdf8;
  --accent-blue: #0284c7;
  --accent-indigo: #818cf8;
  --accent-emerald: #10b981;
  --accent-amber: #f59e0b;
  --accent-purple: #c084fc;
  
  /* Gradients */
  --grad-primary: linear-gradient(135deg, #38bdf8 0%, #818cf8 100%);
  --grad-accent: linear-gradient(135deg, #0284c7 0%, #06b6d4 100%);
  --grad-card: linear-gradient(180deg, rgba(23, 34, 59, 0.6) 0%, rgba(13, 21, 39, 0.85) 100%);
  --grad-glow: radial-gradient(circle at 50% 30%, rgba(56, 189, 248, 0.12) 0%, transparent 65%);

  /* Typography */
  --font-heading: 'Outfit', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-body: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;

  /* Elevations & Shadows */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.25);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 16px 44px rgba(0, 0, 0, 0.55);
  --shadow-glow: 0 0 35px rgba(56, 189, 248, 0.25);

  /* Layout & Transitions */
  --max-width: 1220px;
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-full: 9999px;
  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* --- Light Mode Overrides --- */
[data-theme="light"] {
  --bg-primary: #f8fafc;
  --bg-secondary: #f1f5f9;
  --bg-tertiary: #e2e8f0;
  --bg-card: rgba(255, 255, 255, 0.9);
  --bg-card-hover: rgba(255, 255, 255, 0.98);
  --bg-glass: rgba(255, 255, 255, 0.82);
  --border-color: rgba(15, 23, 42, 0.1);
  --border-hover: rgba(2, 132, 199, 0.5);

  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  --text-inverse: #f8fafc;

  --shadow-sm: 0 2px 8px rgba(15, 23, 42, 0.05);
  --shadow-md: 0 8px 24px rgba(15, 23, 42, 0.08);
  --shadow-lg: 0 16px 40px rgba(15, 23, 42, 0.12);
  --shadow-glow: 0 0 35px rgba(2, 132, 199, 0.15);
  --grad-card: linear-gradient(180deg, rgba(255, 255, 255, 0.95) 0%, rgba(241, 245, 249, 0.75) 100%);
  --grad-glow: radial-gradient(circle at 50% 30%, rgba(2, 132, 199, 0.1) 0%, transparent 65%);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  scroll-padding-top: 85px;
}

body {
  font-family: var(--font-body);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
  transition: background-color var(--transition-normal), color var(--transition-normal);
  background-image: var(--grad-glow);
  background-attachment: fixed;
  background-repeat: no-repeat;
  background-position: top center;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition-fast);
}

img, svg {
  display: block;
  max-width: 100%;
}

button, input, textarea {
  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-primary);
}

.gradient-text {
  background: var(--grad-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
}

/* --- Container & Section Base --- */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: 1.5rem;
  padding-right: 1.5rem;
}

.section {
  padding: 6rem 0;
  position: relative;
}

.section-header {
  text-align: center;
  max-width: 760px;
  margin: 0 auto 3.5rem auto;
}

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-heading);
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--accent-cyan);
  background: rgba(56, 189, 248, 0.1);
  border: 1px solid rgba(56, 189, 248, 0.25);
  padding: 0.35rem 1rem;
  border-radius: var(--radius-full);
  margin-bottom: 1rem;
}

.section-title {
  font-size: 2.35rem;
  margin-bottom: 1rem;
  letter-spacing: -0.5px;
}

.section-subtitle {
  font-size: 1.05rem;
  color: var(--text-secondary);
}

/* --- Navigation Bar --- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: var(--bg-glass);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border-color);
  transition: all var(--transition-normal);
}

.navbar.scrolled {
  box-shadow: var(--shadow-md);
  background: var(--bg-primary);
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 75px;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-family: var(--font-heading);
  font-weight: 800;
  font-size: 1.35rem;
  letter-spacing: -0.5px;
}

.brand-badge {
  width: 38px;
  height: 38px;
  border-radius: 10px;
  background: var(--grad-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #070c18;
  font-weight: 800;
  font-size: 1.1rem;
  box-shadow: 0 4px 12px rgba(56, 189, 248, 0.3);
}

.brand-avatar {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-full);
  object-fit: cover;
  object-position: center top;
  border: 2px solid var(--accent-cyan);
  box-shadow: 0 2px 12px rgba(56, 189, 248, 0.35);
  display: block;
  flex-shrink: 0;
  transition: transform var(--transition-fast), border-color var(--transition-fast);
}

.nav-brand:hover .brand-avatar {
  transform: scale(1.08);
  border-color: #818cf8;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  list-style: none;
}

.nav-link {
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--text-secondary);
  position: relative;
  padding: 0.5rem 0;
  transition: color var(--transition-fast);
}

.nav-link:hover,
.nav-link.active {
  color: var(--accent-cyan);
}

.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: var(--accent-cyan);
  border-radius: 2px;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
}

/* Theme Toggle */
.theme-toggle-btn {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  width: 40px;
  height: 40px;
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.theme-toggle-btn:hover {
  border-color: var(--accent-cyan);
  color: var(--accent-cyan);
  transform: scale(1.05);
}

/* Mobile Toggle */
.mobile-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text-primary);
  cursor: pointer;
  padding: 0.5rem;
  flex-direction: column;
  gap: 5px;
}

.mobile-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background-color: currentColor;
  transition: all var(--transition-fast);
}

/* Mobile Drawer */
.mobile-menu {
  position: fixed;
  top: 75px;
  left: 0;
  width: 100%;
  max-height: calc(100vh - 75px);
  overflow-y: auto;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border-color);
  padding: 1.5rem;
  transform: translateY(-100%);
  opacity: 0;
  pointer-events: none;
  transition: all var(--transition-normal);
  z-index: 999;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  box-shadow: var(--shadow-lg);
}

.mobile-menu.open {
  transform: translateY(0);
  opacity: 1;
  pointer-events: auto;
}

.mobile-menu .nav-link {
  font-size: 1.05rem;
  padding: 0.4rem 0;
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 0.92rem;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: all var(--transition-fast);
  border: 1px solid transparent;
  white-space: nowrap;
}

.btn-primary {
  background: var(--grad-primary);
  color: #070c18;
  box-shadow: 0 4px 16px rgba(56, 189, 248, 0.3);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 22px rgba(56, 189, 248, 0.45);
}

.btn-secondary {
  background: var(--bg-card);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
}

.btn-secondary:hover {
  border-color: var(--accent-cyan);
  color: var(--accent-cyan);
  transform: translateY(-2px);
  background: var(--bg-card-hover);
}

.btn-outline {
  background: transparent;
  color: var(--accent-cyan);
  border: 1px solid var(--accent-cyan);
}

.btn-outline:hover {
  background: rgba(56, 189, 248, 0.1);
  transform: translateY(-2px);
}

.btn-sm {
  padding: 0.5rem 1rem;
  font-size: 0.85rem;
}

/* --- Hero Section --- */
.hero {
  padding-top: 8.5rem;
  padding-bottom: 5.5rem;
  min-height: 88vh;
  display: flex;
  align-items: center;
  position: relative;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 3.5rem;
  align-items: center;
}

.hero-badge-status {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.4rem 1.1rem;
  background: rgba(16, 185, 129, 0.1);
  border: 1px solid rgba(16, 185, 129, 0.3);
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--accent-emerald);
  margin-bottom: 1.5rem;
}

.pulse-dot {
  width: 8px;
  height: 8px;
  background-color: var(--accent-emerald);
  border-radius: 50%;
  box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.7);
  animation: pulseAnimation 2s infinite;
}

@keyframes pulseAnimation {
  0% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.7); }
  70% { transform: scale(1); box-shadow: 0 0 0 8px rgba(16, 185, 129, 0); }
  100% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(16, 185, 129, 0); }
}

.hero-title {
  font-size: 3.4rem;
  line-height: 1.15;
  margin-bottom: 1.15rem;
  letter-spacing: -1px;
}

.hero-role {
  font-size: 1.3rem;
  color: var(--accent-cyan);
  font-weight: 600;
  margin-bottom: 1.35rem;
  letter-spacing: -0.2px;
}

.hero-description {
  font-size: 1.05rem;
  color: var(--text-secondary);
  line-height: 1.75;
  margin-bottom: 2.25rem;
  max-width: 620px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1.1rem;
  margin-bottom: 2.25rem;
}

.hero-socials {
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

.social-icon-link {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: var(--radius-full);
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  transition: all var(--transition-fast);
}

.social-icon-link:hover {
  color: var(--accent-cyan);
  border-color: var(--accent-cyan);
  transform: translateY(-3px);
  box-shadow: 0 4px 14px rgba(56, 189, 248, 0.2);
}

/* Hero Visual & Avatar Card */
.hero-visual {
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero-avatar-wrapper {
  position: relative;
  width: 380px;
  height: 500px;
  display: flex;
  justify-content: center;
  align-items: flex-end;
}

.hero-avatar-glow {
  position: absolute;
  width: 320px;
  height: 400px;
  bottom: 25px;
  background: radial-gradient(circle at center, rgba(56, 189, 248, 0.35) 0%, rgba(129, 140, 248, 0.2) 45%, transparent 70%);
  border-radius: var(--radius-full);
  filter: blur(35px);
  z-index: 1;
}

.hero-avatar-pedestal {
  position: absolute;
  bottom: 0;
  width: 80%;
  height: 30px;
  background: radial-gradient(ellipse at center, rgba(56, 189, 248, 0.5) 0%, transparent 75%);
  border-radius: 50%;
  z-index: 1;
}

.hero-avatar-img {
  width: 100%;
  height: 100%;
  position: relative;
  z-index: 2;
  object-fit: contain;
  object-position: bottom center;
  filter: drop-shadow(0 18px 30px rgba(0, 0, 0, 0.65));
  transition: transform var(--transition-normal);
}

.hero-avatar-img:hover {
  transform: scale(1.02);
}

/* Floating Tech Badges */
.floating-badge {
  position: absolute;
  z-index: 3;
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-color);
  padding: 0.6rem 1.1rem;
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  gap: 0.6rem;
  box-shadow: var(--shadow-md);
  animation: floatUpDown 4s ease-in-out infinite;
  font-size: 0.85rem;
  font-weight: 600;
}

.floating-badge-1 {
  bottom: 110px;
  left: -50px;
  animation-delay: 0s;
}

.floating-badge-2 {
  bottom: 25px;
  right: -50px;
  animation-delay: 2s;
}

@keyframes floatUpDown {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-8px); }
}

/* --- About Section & Profile Card --- */
.about-grid {
  display: grid;
  grid-template-columns: 0.85fr 1.15fr;
  gap: 3.5rem;
  align-items: flex-start;
}

.about-profile-card {
  background: var(--grad-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  box-shadow: var(--shadow-md);
  transition: all var(--transition-normal);
  position: relative;
  overflow: hidden;
  max-width: 380px;
  width: 100%;
  margin: 0 auto;
}

.about-profile-card:hover {
  border-color: var(--accent-cyan);
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.about-profile-img-wrap {
  width: 100%;
  aspect-ratio: 806 / 1024;
  border-radius: var(--radius-md);
  overflow: hidden;
  margin-bottom: 1.25rem;
  border: 1.5px solid var(--border-color);
  background: var(--bg-tertiary);
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
  display: flex;
  align-items: center;
  justify-content: center;
}

.about-profile-img {
  width: 100%;
  height: 100%;
  display: block;
  object-fit: contain;
  transition: transform var(--transition-normal);
}

.about-profile-card:hover .about-profile-img {
  transform: scale(1.03);
}

.about-profile-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.3rem 0.85rem;
  background: rgba(56, 189, 248, 0.1);
  border: 1px solid rgba(56, 189, 248, 0.25);
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--accent-cyan);
  margin-bottom: 0.5rem;
}

.about-profile-name {
  font-size: 1.25rem;
  margin-bottom: 0.25rem;
}

.about-profile-title {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

.about-content-col {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.about-text {
  font-size: 1.05rem;
  color: var(--text-secondary);
  line-height: 1.8;
}

.about-text p {
  margin-bottom: 1.25rem;
}

.about-metrics {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
}

.metric-card {
  background: var(--grad-card);
  border: 1px solid var(--border-color);
  padding: 1.75rem 1.5rem;
  border-radius: var(--radius-md);
  text-align: center;
  transition: all var(--transition-fast);
}

.metric-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent-cyan);
  box-shadow: var(--shadow-md);
}

.metric-number {
  font-family: var(--font-heading);
  font-size: 1.85rem;
  font-weight: 800;
  color: var(--accent-cyan);
  margin-bottom: 0.25rem;
}

.metric-label {
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--text-secondary);
}

/* --- Timeline Architecture (Education & Experience) --- */
.timeline-container {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  position: relative;
  max-width: 1000px;
  margin: 0 auto;
}

.timeline-card {
  background: var(--grad-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 2rem;
  position: relative;
  transition: all var(--transition-fast);
}

.timeline-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

.timeline-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-bottom: 0.85rem;
}

.timeline-title {
  font-size: 1.3rem;
  font-weight: 700;
}

.timeline-institution {
  font-size: 1.05rem;
  color: var(--accent-cyan);
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.timeline-period-badge {
  display: inline-flex;
  align-items: center;
  padding: 0.3rem 0.85rem;
  background: rgba(56, 189, 248, 0.1);
  border: 1px solid rgba(56, 189, 248, 0.25);
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--accent-cyan);
}

.timeline-body {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

.timeline-bullet-list {
  list-style: none;
  margin-top: 0.85rem;
}

.timeline-bullet-list li {
  position: relative;
  padding-left: 1.4rem;
  margin-bottom: 0.5rem;
  font-size: 0.92rem;
  color: var(--text-secondary);
}

.timeline-bullet-list li::before {
  content: '▹';
  position: absolute;
  left: 0;
  color: var(--accent-cyan);
  font-weight: bold;
}

/* --- Skills Section --- */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.75rem;
}

.skill-category-card {
  background: var(--grad-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 2rem 1.75rem;
  transition: all var(--transition-normal);
  position: relative;
  overflow: hidden;
}

.skill-category-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: var(--grad-primary);
  opacity: 0;
  transition: opacity var(--transition-fast);
}

.skill-category-card:hover {
  transform: translateY(-5px);
  border-color: var(--border-hover);
  box-shadow: var(--shadow-md);
}

.skill-category-card:hover::before {
  opacity: 1;
}

.skill-cat-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.skill-cat-icon {
  width: 46px;
  height: 46px;
  border-radius: 12px;
  background: rgba(56, 189, 248, 0.1);
  color: var(--accent-cyan);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.35rem;
}

.skill-cat-title {
  font-size: 1.25rem;
  font-weight: 700;
}

.skill-tags-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}

.skill-pill {
  background: var(--bg-tertiary);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  padding: 0.4rem 0.85rem;
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-weight: 500;
  transition: all var(--transition-fast);
}

.skill-pill:hover {
  background: rgba(56, 189, 248, 0.15);
  border-color: var(--accent-cyan);
  color: var(--accent-cyan);
  transform: translateY(-2px);
}

/* --- Projects Section --- */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: 2rem;
}

.project-card {
  background: var(--grad-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: all var(--transition-normal);
}

.project-card:hover {
  transform: translateY(-6px);
  border-color: var(--border-hover);
  box-shadow: var(--shadow-lg);
}

.project-img-wrapper {
  width: 100%;
  height: 215px;
  background: var(--bg-secondary);
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid var(--border-color);
}

.project-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition-normal);
}

.project-card:hover .project-img {
  transform: scale(1.03);
}

.project-badge-pill {
  position: absolute;
  top: 1rem;
  left: 1rem;
  background: rgba(13, 21, 39, 0.88);
  backdrop-filter: blur(8px);
  border: 1px solid var(--border-color);
  color: var(--accent-cyan);
  padding: 0.25rem 0.75rem;
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
}

.project-body {
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  flex-grow: 1;
}

.project-title {
  font-size: 1.35rem;
  margin-bottom: 0.75rem;
}

.project-desc {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 1.25rem;
  flex-grow: 1;
}

.project-highlights {
  list-style: none;
  margin-bottom: 1.25rem;
}

.project-highlights li {
  font-size: 0.85rem;
  color: var(--text-muted);
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
  margin-bottom: 0.4rem;
}

.project-highlights li svg {
  color: var(--accent-emerald);
  flex-shrink: 0;
  margin-top: 3px;
}

.project-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
}

.project-tag {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent-cyan);
  background: rgba(56, 189, 248, 0.1);
  padding: 0.25rem 0.65rem;
  border-radius: 4px;
}

.project-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
}

/* --- Research & IEEE Publication Highlight Section --- */
.publication-card {
  background: var(--grad-card);
  border: 2px solid rgba(56, 189, 248, 0.35);
  border-radius: var(--radius-lg);
  padding: 2.75rem;
  margin-bottom: 3.5rem;
  position: relative;
  box-shadow: var(--shadow-glow);
}

.pub-badge-top {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: #006699;
  color: #ffffff;
  padding: 0.35rem 0.9rem;
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.5px;
  margin-bottom: 1.25rem;
}

.pub-title {
  font-size: 1.85rem;
  line-height: 1.3;
  margin-bottom: 1rem;
}

.pub-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  margin-bottom: 1.5rem;
  font-size: 0.92rem;
  color: var(--text-secondary);
}

.pub-meta-item strong {
  color: var(--text-primary);
}

.pub-summary {
  font-size: 1.05rem;
  color: var(--text-secondary);
  line-height: 1.75;
  margin-bottom: 1.75rem;
}

.pub-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1.25rem;
}

.doi-pill {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--accent-cyan);
  background: rgba(56, 189, 248, 0.08);
  border: 1px solid rgba(56, 189, 248, 0.25);
  padding: 0.5rem 1rem;
  border-radius: var(--radius-sm);
}

/* Conference Grid */
.conference-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(290px, 1fr));
  gap: 1.75rem;
}

.conference-card {
  background: var(--grad-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.75rem;
  transition: all var(--transition-fast);
}

.conference-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent-cyan);
  box-shadow: var(--shadow-md);
}

.conf-tag {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--accent-indigo);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 0.5rem;
}

.conf-title {
  font-size: 1.15rem;
  margin-bottom: 0.5rem;
}

.conf-desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* --- Awards & Leadership Section --- */
.awards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 1.5rem;
}

.award-card {
  background: var(--grad-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.75rem;
  display: flex;
  gap: 1.25rem;
  align-items: flex-start;
  transition: all var(--transition-fast);
}

.award-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent-amber);
  box-shadow: var(--shadow-md);
}

.award-icon-box {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  background: rgba(245, 158, 11, 0.12);
  color: var(--accent-amber);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.35rem;
  flex-shrink: 0;
}

.award-content h4 {
  font-size: 1.1rem;
  margin-bottom: 0.35rem;
}

.award-event {
  font-size: 0.88rem;
  color: var(--accent-cyan);
  font-weight: 600;
  margin-bottom: 0.4rem;
}

.award-desc {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.55;
}

/* --- Contact Us Section --- */
.contact-grid {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 3.5rem;
  align-items: flex-start;
}

.contact-info-col {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.contact-card-item {
  display: flex;
  align-items: flex-start;
  gap: 1.25rem;
  padding: 1.5rem;
  background: var(--grad-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.contact-card-item:hover {
  transform: translateX(5px);
  border-color: var(--accent-cyan);
}

.contact-icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  background: rgba(56, 189, 248, 0.1);
  color: var(--accent-cyan);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  flex-shrink: 0;
}

.contact-info-content h4 {
  font-size: 1rem;
  margin-bottom: 0.25rem;
}

.contact-info-content p,
.contact-info-content a {
  font-size: 0.92rem;
  color: var(--text-secondary);
}

.contact-info-content a:hover {
  color: var(--accent-cyan);
}

/* Contact Form */
.contact-form-wrapper {
  background: var(--grad-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  box-shadow: var(--shadow-md);
}

.form-group {
  margin-bottom: 1.35rem;
}

.form-label {
  display: block;
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}

.form-control {
  width: 100%;
  padding: 0.85rem 1.1rem;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 0.95rem;
  transition: all var(--transition-fast);
}

.form-control:focus {
  outline: none;
  border-color: var(--accent-cyan);
  box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.2);
}

.form-control::placeholder {
  color: var(--text-muted);
}

textarea.form-control {
  resize: vertical;
  min-height: 120px;
}

.form-feedback {
  margin-top: 1rem;
  padding: 0.85rem 1rem;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  display: none;
}

.form-feedback.success {
  display: block;
  background: rgba(16, 185, 129, 0.15);
  color: var(--accent-emerald);
  border: 1px solid rgba(16, 185, 129, 0.3);
}

.form-feedback.error {
  display: block;
  background: rgba(239, 68, 68, 0.15);
  color: #f87171;
  border: 1px solid rgba(239, 68, 68, 0.3);
}

/* --- Footer --- */
.footer {
  border-top: 1px solid var(--border-color);
  background: var(--bg-secondary);
  padding: 3.5rem 0 2rem 0;
  position: relative;
}

.footer-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 1.75rem;
  margin-bottom: 2.5rem;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 1.75rem;
  list-style: none;
}

.footer-link {
  font-size: 0.92rem;
  color: var(--text-secondary);
}

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

.footer-bottom {
  border-top: 1px solid var(--border-color);
  padding-top: 1.75rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* Floating Back-to-Top */
.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 44px;
  height: 44px;
  border-radius: var(--radius-full);
  background: var(--grad-primary);
  color: #070c18;
  border: none;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  z-index: 900;
  opacity: 0;
  pointer-events: none;
  transform: translateY(15px);
  transition: all var(--transition-fast);
  box-shadow: 0 4px 14px rgba(56, 189, 248, 0.35);
}

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

.back-to-top:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 20px rgba(56, 189, 248, 0.5);
}

/* Toast */
.toast-container {
  position: fixed;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  border: 1px solid var(--accent-cyan);
  color: var(--text-primary);
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-full);
  box-shadow: var(--shadow-lg);
  font-size: 0.9rem;
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  z-index: 2000;
  opacity: 0;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.toast-container.show {
  transform: translateX(-50%) translateY(0);
  opacity: 1;
}

/* --- Responsive Media Queries --- */
@media (max-width: 992px) {
  .hero-grid,
  .about-grid,
  .contact-grid {
    grid-template-columns: 1fr;
    gap: 3rem;
  }

  .hero {
    text-align: center;
    padding-top: 7.5rem;
  }

  .hero-badge-status,
  .hero-description {
    margin-left: auto;
    margin-right: auto;
  }

  .hero-actions,
  .hero-socials {
    justify-content: center;
  }

  .hero-visual {
    order: -1;
  }

  .hero-avatar-wrapper {
    width: 320px;
    height: 420px;
  }

  .floating-badge-1 {
    bottom: 80px;
    left: -20px;
  }

  .floating-badge-2 {
    bottom: 15px;
    right: -20px;
  }

  .nav-links {
    display: none;
  }

  .mobile-toggle {
    display: flex;
  }
}

@media (max-width: 640px) {
  .section {
    padding: 4.5rem 0;
  }

  .hero-title {
    font-size: 2.35rem;
  }

  .hero-role {
    font-size: 1.15rem;
  }

  .hero-avatar-wrapper {
    width: 270px;
    height: 360px;
  }

  .floating-badge-1 {
    bottom: 60px;
    left: -10px;
  }

  .floating-badge-2 {
    bottom: 10px;
    right: -10px;
  }

  .floating-badge {
    padding: 0.4rem 0.8rem;
    font-size: 0.75rem;
  }

  .about-metrics {
    grid-template-columns: 1fr;
  }

  .publication-card {
    padding: 1.5rem;
  }

  .pub-title {
    font-size: 1.35rem;
  }

  .contact-form-wrapper {
    padding: 1.5rem;
  }

  .footer-bottom {
    flex-direction: column;
    gap: 1rem;
    text-align: center;
  }

  .btn {
    width: 100%;
  }

  .hero-actions {
    flex-direction: column;
    width: 100%;
  }
}