/*!
 * Professional Academic Portfolio Theme
 * Warm, elegant design for optics/research professionals
 */

/* ===============================================
   CSS CUSTOM PROPERTIES (DESIGN SYSTEM)
   =============================================== */

:root {
  /* Light Mode - Warm Beige/Brown Professional */
  --bg-primary: #FDFBF7;        /* Warm off-white */
  --bg-secondary: #F5F0E8;      /* Light beige */
  --bg-tertiary: #EDE6DB;       /* Slightly darker beige */
  --text-primary: #2C2416;      /* Dark brown/charcoal */
  --text-secondary: #5C5040;    /* Medium brown */
  --text-muted: #8B8070;        /* Muted brown */
  --accent: #8B5A2B;            /* Warm brown accent */
  --accent-hover: #6B4423;      /* Darker brown */
  --accent-light: #C4956A;      /* Light tan accent */
  --border: #E0D6C8;            /* Warm border */
  --border-hover: #C9BBA8;      /* Darker warm border */
  --highlight: #D4A574;         /* Gold/tan highlight */
  
  /* Shadows - Warm tinted */
  --shadow-sm: 0 1px 2px 0 rgba(44, 36, 22, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(44, 36, 22, 0.1), 0 2px 4px -1px rgba(44, 36, 22, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(44, 36, 22, 0.1), 0 4px 6px -2px rgba(44, 36, 22, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(44, 36, 22, 0.1), 0 10px 10px -5px rgba(44, 36, 22, 0.04);
  
  /* Spacing */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-24: 6rem;
  
  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  /* Softer Apple-like squircle corners */
  --radius-squircle: 1.25rem;
  --radius-full: 9999px;
  
  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 200ms ease;
  --transition-slow: 300ms ease;
}

/* Dark Mode - Warm Dark Professional */
[data-theme="dark"] {
  --bg-primary: #1A1612;        /* Dark warm brown */
  --bg-secondary: #252019;      /* Slightly lighter */
  --bg-tertiary: #302820;       /* Card backgrounds */
  --text-primary: #F5F0E8;      /* Warm off-white */
  --text-secondary: #C9BBA8;    /* Muted cream */
  --text-muted: #8B8070;        /* Muted brown */
  --accent: #C4956A;            /* Warm tan accent */
  --accent-hover: #D4A574;      /* Lighter tan */
  --accent-light: #8B5A2B;      /* Darker accent */
  --border: #3D3428;            /* Warm dark border */
  --border-hover: #4D4438;      /* Lighter border */
  --highlight: #D4A574;         /* Gold highlight */
  
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4), 0 2px 4px -1px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4), 0 4px 6px -2px rgba(0, 0, 0, 0.3);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.5), 0 10px 10px -5px rgba(0, 0, 0, 0.4);
}

/* ===============================================
   BASE STYLES
   =============================================== */

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-primary);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background-color var(--transition-slow), color var(--transition-slow);
}

/* ===============================================
   TYPOGRAPHY
   =============================================== */

h1, h2, h3, h4, h5, h6 {
  font-family: 'Inter', system-ui, sans-serif;
  font-weight: 600;
  letter-spacing: -0.02em;
  line-height: 1.3;
  color: var(--text-primary);
}

h1 { font-size: 3rem; }
h2 { font-size: 2.25rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }
h5 { font-size: 1.125rem; }
h6 { font-size: 1rem; }

p {
  color: var(--text-secondary);
  line-height: 1.75;
  margin-bottom: var(--space-4);
}

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

a:hover {
  color: var(--accent-hover);
}

.text-muted {
  color: var(--text-muted) !important;
}

/* ===============================================
   NAVIGATION
   =============================================== */

#mainNav {
  background: rgba(253, 251, 247, 0.9) !important;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  transition: all var(--transition-base);
  padding: var(--space-3) 0;
}

[data-theme="dark"] #mainNav {
  background: rgba(26, 22, 18, 0.95) !important;
  border-bottom-color: var(--border);
}

#mainNav.navbar-shrink {
  box-shadow: var(--shadow-sm);
}

.navbar-brand {
  font-weight: 700 !important;
  font-size: 1.25rem !important;
  color: var(--text-primary) !important;
  letter-spacing: -0.02em;
  transition: color var(--transition-fast);
}

.navbar-brand:hover {
  color: var(--accent) !important;
}

.navbar-nav .nav-link {
  font-size: 0.875rem !important;
  font-weight: 500 !important;
  color: var(--text-secondary) !important;
  padding: var(--space-2) var(--space-4) !important;
  transition: color var(--transition-fast);
  position: relative;
}

.navbar-nav .nav-link:hover,
.navbar-nav .nav-link.active {
  color: var(--text-primary) !important;
}

.navbar-nav .nav-link::after {
  display: none !important;
}

/* Theme Toggle */
.theme-toggle {
  background: transparent;
  border: none;
  color: var(--text-secondary);
  width: 40px;
  height: 40px;
  border-radius: calc(var(--radius-squircle) - 0.5rem);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.theme-toggle:hover {
  background: var(--bg-tertiary);
  color: var(--text-primary);
}

.theme-toggle i {
  font-size: 1.125rem;
}

/* Navbar Controls Container */
.navbar-controls {
	display: none;
	align-items: center;
	gap: var(--space-2);
	margin-left: auto;
}

/* Theme toggle visibility */
.theme-toggle-mobile {
	display: none;
}

.theme-toggle-desktop {
	display: block;
}

/* Mobile Navigation */
.navbar-toggler {
	border: 1px solid var(--border) !important;
	padding: var(--space-2) var(--space-3) !important;
	font-size: 0.875rem !important;
	color: var(--text-primary) !important;
	background: var(--bg-secondary) !important;
	border-radius: calc(var(--radius-squircle) - 0.5rem);
}

@media (max-width: 991px) {
	.navbar-collapse {
		background: var(--bg-primary);
		padding: var(--space-4);
		border-radius: var(--radius-squircle);
		margin-top: var(--space-2);
		border: 1px solid var(--border);
	}
	
	.navbar-nav .nav-link {
		padding: var(--space-3) var(--space-4) !important;
	}
	
	/* Show mobile theme toggle, hide desktop version */
	.navbar-controls {
		display: flex;
	}
	
	.theme-toggle-mobile {
		display: block;
	}
	
	.theme-toggle-desktop {
		display: none;
	}
}

@media (max-width: 576px) {
  .navbar-collapse {
    padding: var(--space-3);
    margin-top: var(--space-1);
  }
  
  .navbar-nav .nav-link {
    padding: var(--space-2) var(--space-3) !important;
    font-size: 0.8125rem !important;
  }
}

/* ===============================================
   HERO SECTION (MASTHEAD)
   =============================================== */

header.masthead {
  text-align: center;
  color: white;
  background-image: linear-gradient(rgba(0, 0, 0, 0.7), rgba(0, 0, 0, 0.7)), url("../img/header-bg.jpg");
  background-repeat: no-repeat;
  background-attachment: fixed;
  background-position: center center;
  background-size: cover;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
}

header.masthead .intro-text {
  padding: var(--space-24) var(--space-4);
}

/* Hero buttons: align horizontally (wrap if needed) */
header.masthead .hero-actions {
  margin-top: var(--space-6);
  display: flex;
  justify-content: center;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-3);
}

header.masthead .hero-actions .btn {
  margin: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 180px;
}

header.masthead .intro-lead-in {
  font-size: 1.25rem;
  font-weight: 400;
  color: rgba(255, 255, 255, 0.9);
  margin-bottom: var(--space-4);
  font-style: normal;
  font-family: 'Inter', system-ui, sans-serif;
}

header.masthead .intro-heading {
  font-size: 3.5rem;
  font-weight: 700;
  color: white;
  margin-bottom: var(--space-8);
  letter-spacing: -0.03em;
  line-height: 1.1;
  text-transform: none;
  background: none;
  -webkit-background-clip: unset;
  -webkit-text-fill-color: unset;
  background-clip: unset;
  animation: none;
}

@media (min-width: 768px) {
  header.masthead .intro-heading {
    font-size: 4.5rem;
  }
  
  header.masthead .intro-lead-in {
    font-size: 1.5rem;
  }
}

/* Mobile hero adjustments */
@media (max-width: 576px) {
  header.masthead {
    min-height: auto;
    padding: var(--space-16) 0;
  }
  
  header.masthead .intro-text {
    padding: var(--space-8) var(--space-4);
  }
  
  header.masthead .intro-heading {
    font-size: 2rem;
    line-height: 1.2;
    margin-bottom: var(--space-4);
  }
  
  header.masthead .intro-lead-in {
    font-size: 1rem;
    margin-bottom: var(--space-3);
  }
  
  .intro-institution {
    font-size: 0.875rem !important;
  }
}

/* ===============================================
   BUTTONS
   =============================================== */

.btn {
  font-family: 'Inter', system-ui, sans-serif;
  font-weight: 500;
  font-size: 0.9375rem;
  padding: var(--space-3) var(--space-6);
  border-radius: calc(var(--radius-squircle) - 0.25rem);
  transition: all var(--transition-fast);
  border: none;
  cursor: pointer;
}

.btn-primary {
  background-color: var(--accent);
  color: white;
  border: none;
}

.btn-primary:hover,
.btn-primary:focus {
  background-color: var(--accent-hover);
  color: white;
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

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

.btn-outline-primary:hover {
  background: var(--accent);
  color: white;
}

.btn-xl {
  font-size: 1rem;
  padding: var(--space-4) var(--space-8);
  border-radius: calc(var(--radius-squircle) - 0.25rem);
}

/* Mobile button adjustments */
@media (max-width: 576px) {
  .btn-xl {
    padding: var(--space-3) var(--space-6);
    font-size: 0.875rem;
    display: block;
    width: 100%;
    margin: var(--space-2) 0;
  }

  /* Override global full-width buttons inside hero */
  header.masthead .hero-actions .btn-xl {
    width: auto;
    display: inline-flex;
    flex: 1 1 140px;
    min-width: 140px;
    margin: 0;
  }
}

.btn-gradient {
  background: var(--accent);
  border: none;
  color: white;
  margin: var(--space-4);
  padding: var(--space-4) var(--space-8);
  border-radius: calc(var(--radius-squircle) - 0.25rem);
  font-weight: 600;
  transition: all var(--transition-fast);
  box-shadow: var(--shadow-md);
}

.btn-gradient:hover {
  background: var(--accent-hover);
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
  color: white;
  text-decoration: none;
}

@media (max-width: 576px) {
  /* Keep hero buttons neatly grouped */
  header.masthead .hero-actions {
    width: 100%;
    gap: var(--space-2);
  }
  
  /* Remove extra margins added by .btn-gradient in hero */
  header.masthead .hero-actions .btn-gradient {
    margin: 0;
  }
}

/* ===============================================
   SECTIONS
   =============================================== */

section {
  padding: var(--space-16) 0;
  background: var(--bg-primary);
  transition: background-color var(--transition-slow);
}

/* Mobile section padding */
@media (max-width: 576px) {
  section {
    padding: var(--space-8) 0;
  }
  
  .py-5 {
    padding-top: var(--space-8) !important;
    padding-bottom: var(--space-8) !important;
  }
}

section.bg-light,
#portfolio,
#skills,
#certifications,
#blog,
#achievements {
  background: var(--bg-secondary) !important;
}

.section-heading {
  font-size: 2.25rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: var(--space-4);
  position: relative;
}

.section-heading::after {
  content: '';
  position: absolute;
  bottom: -8px;
  left: 50%;
  transform: translateX(-50%);
  width: 48px;
  height: 3px;
  background: var(--accent);
  border-radius: var(--radius-full);
}

.section-subheading {
  font-size: 1.125rem;
  font-weight: 400;
  color: var(--text-secondary) !important;
  margin-bottom: var(--space-8);
  font-style: normal;
  font-family: 'Inter', system-ui, sans-serif;
}

.section-subsubheading {
  font-size: 1rem;
  color: var(--text-muted) !important;
  margin-top: var(--space-4);
}

/* ===============================================
   CARDS
   =============================================== */

.portfolio-card,
.blog-card,
.expertise-card,
.certification-card,
.achievement-card {
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-squircle);
  overflow: hidden;
  transition: all var(--transition-base);
  height: 100%;
}

.portfolio-card:hover,
.blog-card:hover,
.expertise-card:hover,
.certification-card:hover,
.achievement-card:hover {
  border-color: var(--border-hover);
  box-shadow: var(--shadow-lg);
  transform: translateY(-4px);
}

/* Remove gradient borders */
.portfolio-card::before,
.blog-card::before,
.expertise-card::before,
.certification-card::before,
.achievement-card::before {
  display: none !important;
}

/* ===============================================
   PORTFOLIO SECTION
   =============================================== */

.portfolio-container {
  margin-top: var(--space-8);
}

.portfolio-link {
  display: block;
  position: relative;
  width: 100%;
  height: 220px;
  overflow: hidden;
}

/* Mobile portfolio image adjustments */
@media (max-width: 576px) {
  .portfolio-link {
    height: 180px;
  }
}

.portfolio-link img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition-slow);
}

.portfolio-card:hover .portfolio-link img {
  transform: scale(1.05);
}

.portfolio-hover {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(139, 90, 43, 0.9);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transition: opacity var(--transition-base);
}

.portfolio-card:hover .portfolio-hover {
  opacity: 1;
}

.portfolio-hover-content {
  color: white;
  text-align: center;
}

.portfolio-hover-content i {
  font-size: 2.5rem;
}

.portfolio-caption {
  padding: var(--space-6);
  background: var(--bg-primary);
}

.portfolio-caption h4 {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--space-2);
}

.portfolio-caption p {
  font-size: 0.875rem;
  color: var(--text-muted);
  margin: 0;
  font-style: normal;
}

.portfolio-cta {
  margin-top: var(--space-4);
  padding-top: var(--space-4);
  border-top: 1px solid var(--border);
}

.portfolio-cta .btn {
  font-size: 0.8125rem;
  padding: var(--space-2) var(--space-4);
  border-radius: calc(var(--radius-squircle) - 0.75rem);
}

/* ===============================================
   SKILLS SECTION
   =============================================== */

.expertise-card {
  padding: var(--space-6);
}

.expertise-header {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  margin-bottom: var(--space-6);
  padding-bottom: var(--space-4);
  border-bottom: 1px solid var(--border);
}

.expertise-header i {
  font-size: 1.5rem;
  color: var(--accent);
  background: var(--bg-secondary);
  padding: var(--space-4);
  border-radius: var(--radius-squircle);
}

.expertise-header h4 {
  margin: 0;
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text-primary);
}

.expertise-content {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.expertise-item {
  padding: var(--space-4);
  background: var(--bg-secondary);
  border-radius: calc(var(--radius-squircle) - 0.5rem);
  border: 1px solid var(--border);
  transition: background-color var(--transition-fast);
}

.expertise-item:hover {
  background: var(--bg-tertiary);
}

.expertise-title {
  display: inline-block;
  font-weight: 600;
  font-size: 0.9375rem;
  color: var(--text-primary);
  background: var(--accent);
  color: white;
  padding: var(--space-1) var(--space-3);
  border-radius: calc(var(--radius-squircle) - 0.75rem);
  margin-bottom: var(--space-2);
  max-width: 100%;
  overflow-wrap: anywhere;
}

/* Remove rainbow gradient from titles */
.expertise-title::after,
.certification-title::after,
.achievement-title::after {
  display: none !important;
}

.expertise-item p {
  margin: 0;
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.expertise-item.highlight {
  background: rgba(139, 90, 43, 0.08);
  border-color: rgba(139, 90, 43, 0.35);
  box-shadow: 0 6px 18px rgba(44, 36, 22, 0.06);
}

.thm-link {
  color: var(--accent) !important;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.thm-link:hover {
  color: var(--accent-hover) !important;
}

.thm-link i {
  color: #fbbf24;
}

/* ===============================================
   CERTIFICATIONS SECTION
   =============================================== */

.certification-card {
  padding: var(--space-6);
}

.certification-header {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  margin-bottom: var(--space-6);
  padding-bottom: var(--space-4);
  border-bottom: 1px solid var(--border);
}

.certification-header i {
  font-size: 1.5rem;
  color: var(--accent);
  background: var(--bg-secondary);
  padding: var(--space-4);
  border-radius: var(--radius-squircle);
}

.certification-header h4 {
  margin: 0;
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text-primary);
}

.certification-content {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.certification-item {
  padding: var(--space-4);
  background: var(--bg-secondary);
  border-radius: calc(var(--radius-squircle) - 0.25rem);
  border: 1px solid var(--border);
  transition: background-color var(--transition-fast);
}

.certification-item:hover {
  background: var(--bg-tertiary);
}

.certification-item.highlight {
  background: rgba(139, 90, 43, 0.08);
  border-color: rgba(139, 90, 43, 0.35);
  box-shadow: 0 6px 18px rgba(44, 36, 22, 0.06);
}

.certification-item.in-progress {
  background: rgba(251, 191, 36, 0.1);
  border-left: 3px solid #f59e0b;
}

.certification-title {
  display: block;
  width: 100%;
  font-weight: 650;
  font-size: 0.95rem;
  line-height: 1.35;
  letter-spacing: -0.01em;
  color: white;
  background: var(--accent);
  padding: 0.75rem 1rem;
  border-radius: calc(var(--radius-squircle) - 0.25rem);
  margin-bottom: var(--space-3);
  white-space: normal;
  overflow-wrap: anywhere;
}

/* Make publication title link feel like a single clean tap-target */
.certification-item > a {
  display: block;
}

.certification-item p {
  margin: 0 0 var(--space-1) 0;
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.certification-details {
  margin: var(--space-2) 0 0 0;
  padding-left: var(--space-4);
  color: var(--text-secondary);
  font-size: 0.875rem;
}

.certification-details li {
  margin-bottom: var(--space-1);
}

.journal-info {
  font-style: italic;
  color: var(--text-secondary) !important;
}

.doi-info {
  color: var(--accent) !important;
  font-size: 0.8125rem !important;
  font-family: 'SF Mono', Monaco, 'Cascadia Code', monospace;
  overflow-wrap: anywhere;
  word-break: break-word;
}

/* ===============================================
   BLOG SECTION
   =============================================== */

.blog-card {
  display: flex;
  flex-direction: column;
}

.blog-header {
  padding: var(--space-4) var(--space-6) 0;
}

.blog-category {
  display: inline-block;
  background: var(--accent);
  color: white;
  padding: var(--space-1) var(--space-3);
  border-radius: calc(var(--radius-squircle) - 0.75rem);
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.blog-content {
  padding: var(--space-4) var(--space-6) var(--space-6);
  flex: 1;
  display: flex;
  flex-direction: column;
}

.blog-title {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--space-3);
  line-height: 1.4;
}

.blog-excerpt {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.6;
  flex: 1;
  margin-bottom: var(--space-4);
}

.blog-meta {
  margin-top: auto;
  padding-top: var(--space-4);
  border-top: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.blog-date {
  font-size: 0.8125rem;
  color: var(--text-muted);
  font-weight: 500;
}

.blog-read-more {
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--accent);
}

.blog-read-more:hover {
  color: var(--accent-hover);
}

/* ===============================================
   ACHIEVEMENTS SECTION
   =============================================== */

.achievement-card {
  padding: var(--space-6);
}

.achievement-header {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  margin-bottom: var(--space-6);
  padding-bottom: var(--space-4);
  border-bottom: 1px solid var(--border);
}

.achievement-header i {
  font-size: 1.5rem;
  color: var(--accent);
  background: var(--bg-secondary);
  padding: var(--space-4);
  border-radius: var(--radius-squircle);
}

.achievement-header h4 {
  margin: 0;
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text-primary);
}

.achievement-content {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.achievement-item {
  padding: var(--space-4);
  background: var(--bg-secondary);
  border-radius: calc(var(--radius-squircle) - 0.5rem);
  border: 1px solid var(--border);
  transition: background-color var(--transition-fast);
}

.achievement-item:hover {
  background: var(--bg-tertiary);
}

.achievement-title {
  display: inline-block;
  font-weight: 600;
  font-size: 0.9375rem;
  color: white;
  background: var(--accent);
  padding: var(--space-1) var(--space-3);
  border-radius: calc(var(--radius-squircle) - 0.75rem);
  margin-bottom: var(--space-2);
  max-width: 100%;
  overflow-wrap: anywhere;
}

.achievement-item p {
  margin: 0;
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.achievement-item.highlight {
  background: rgba(139, 90, 43, 0.08);
  border-color: rgba(139, 90, 43, 0.35);
  box-shadow: 0 6px 18px rgba(44, 36, 22, 0.06);
}

/* ===============================================
   TIMELINE
   =============================================== */

.timeline {
  position: relative;
  padding: 0;
  list-style: none;
}

.timeline::before {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 40px;
  width: 2px;
  margin-left: -1px;
  content: '';
  background-color: var(--border);
}

.timeline > li {
  position: relative;
  min-height: 50px;
  margin-bottom: var(--space-12);
}

.timeline > li::after,
.timeline > li::before {
  display: table;
  content: ' ';
}

.timeline > li::after {
  clear: both;
}

.timeline > li .timeline-panel {
  position: relative;
  float: right;
  width: 100%;
  padding: 0 var(--space-4) 0 100px;
  text-align: left;
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-squircle);
  padding: var(--space-6);
  margin-left: 80px;
  width: calc(100% - 80px);
}

.timeline > li .timeline-image {
  position: absolute;
  z-index: 100;
  left: 0;
  width: 80px;
  height: 80px;
  text-align: center;
  color: white;
  border: 4px solid var(--border);
  border-radius: 50%;
  background-color: var(--accent);
  display: flex;
  align-items: center;
  justify-content: center;
}

.timeline > li .timeline-image h4 {
  font-size: 0.625rem;
  line-height: 1.3;
  color: white;
  margin: 0;
}

.timeline > li .timeline-image i {
  font-size: 1.5rem;
}

.timeline .timeline-heading h4 {
  margin-top: 0;
  margin-bottom: var(--space-2);
  color: var(--text-primary);
  font-weight: 600;
}

.timeline .timeline-heading h4.subheading {
  font-size: 1rem;
  font-weight: 500;
  color: var(--text-secondary);
  text-transform: none;
}

.timeline .timeline-body > p {
  margin-bottom: 0;
  color: var(--text-secondary);
  font-size: 0.9375rem;
}

@media (min-width: 768px) {
  .timeline::before {
    left: 50%;
  }
  
  .timeline > li {
    min-height: 100px;
    margin-bottom: var(--space-16);
  }
  
  .timeline > li .timeline-panel {
    float: left;
    width: 41%;
    padding: var(--space-6);
    margin-left: 0;
    text-align: right;
  }
  
  .timeline > li .timeline-image {
    left: 50%;
    width: 100px;
    height: 100px;
    margin-left: -50px;
  }
  
  .timeline > li .timeline-image h4 {
    font-size: 0.75rem;
  }
  
  .timeline > li .timeline-image i {
    font-size: 2rem;
  }
  
  .timeline > li.timeline-inverted > .timeline-panel {
    float: right;
    text-align: left;
  }
}

@media (min-width: 992px) {
  .timeline > li .timeline-image {
    width: 120px;
    height: 120px;
    margin-left: -60px;
  }
  
  .timeline > li .timeline-image h4 {
    font-size: 0.875rem;
  }
  
  .timeline > li .timeline-image i {
    font-size: 2.5rem;
  }
}

/* ===============================================
   CONTACT SECTION
   =============================================== */

section#contact {
  background-color: var(--bg-tertiary);
  background-image: none;
  padding: var(--space-16) 0;
}

section#contact .section-heading {
  color: var(--text-primary);
}

/* ===============================================
   FOOTER
   =============================================== */

footer {
  padding: var(--space-8) 0;
  text-align: center;
  background: var(--bg-primary);
  border-top: 1px solid var(--border);
}

footer .copyright {
  font-size: 0.875rem;
  color: var(--text-muted);
}

/* ===============================================
   MODALS
   =============================================== */

.portfolio-modal .modal-dialog {
  max-width: 900px;
  margin: var(--space-8) auto;
}

.portfolio-modal .modal-content {
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-squircle);
  padding: var(--space-8);
}

.portfolio-modal .modal-content h2 {
  font-size: 1.75rem;
  color: var(--text-primary);
  margin-bottom: var(--space-4);
}

.portfolio-modal .modal-content p {
  color: var(--text-secondary);
}

.portfolio-modal .modal-content p.item-intro {
  font-size: 0.9375rem;
  color: var(--text-muted);
  font-style: normal;
  font-family: 'Inter', system-ui, sans-serif;
}

.portfolio-modal .close-modal {
  position: absolute;
  top: var(--space-4);
  right: var(--space-4);
  width: 40px;
  height: 40px;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: calc(var(--radius-squircle) - 0.5rem);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  color: var(--text-secondary);
  transition: all var(--transition-fast);
}

.portfolio-modal .close-modal:hover {
  background: var(--bg-tertiary);
  color: var(--text-primary);
}

.modal-img-row {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: var(--space-6);
  margin: var(--space-6) 0;
}

.modal-img-large {
  max-width: 45%;
  height: auto;
  border-radius: calc(var(--radius-squircle) - 0.25rem);
  border: 1px solid var(--border);
}

@media (max-width: 768px) {
  .modal-img-row {
    flex-direction: column;
  }
  
  .modal-img-large {
    max-width: 100%;
  }
}

@media (max-width: 576px) {
  .portfolio-modal .modal-dialog {
    margin: var(--space-4) auto;
  }
  
  .portfolio-modal .modal-content {
    padding: var(--space-4);
  }
  
  .portfolio-modal .modal-content h2 {
    font-size: 1.5rem;
  }
  
  .portfolio-modal .close-modal {
    width: 32px;
    height: 32px;
    font-size: 1rem;
  }
  
  .modal-img-row {
    gap: var(--space-4);
    margin: var(--space-4) 0;
  }
}

/* ===============================================
   ANIMATIONS
   =============================================== */

/* Simple fade-in for scroll reveal */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* WOW.js compatibility */
.wow {
  visibility: visible !important;
}

.fadeIn,
.fadeInUp {
  animation-name: fadeInUp;
  animation-duration: 0.6s;
  animation-fill-mode: both;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ===============================================
   UTILITIES
   =============================================== */

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

.text-uppercase {
  text-transform: uppercase;
}

.mb-4 {
  margin-bottom: var(--space-4);
}

.mt-5 {
  margin-top: var(--space-8);
}

.py-5 {
  padding-top: var(--space-12);
  padding-bottom: var(--space-12);
}

/* ===============================================
   RESPONSIVE ADJUSTMENTS
   =============================================== */

@media (max-width: 768px) {
  h1 { font-size: 2.25rem; }
  h2 { font-size: 1.75rem; }
  
  .section-heading {
    font-size: 1.75rem;
  }
  
  section {
    padding: var(--space-12) 0;
  }
  
  header.masthead .intro-heading {
    font-size: 2.5rem;
  }
  
  header.masthead .intro-lead-in {
    font-size: 1.125rem;
  }
  
  .btn-xl {
    padding: var(--space-3) var(--space-6);
    font-size: 0.9375rem;
  }
  
  .timeline > li .timeline-panel {
    padding: var(--space-4);
    margin-left: 60px;
    width: calc(100% - 60px);
  }
  
  .timeline > li .timeline-image {
    width: 60px;
    height: 60px;
  }
  
  .timeline > li .timeline-image i {
    font-size: 1.25rem;
  }
}

/* Small mobile devices (< 576px) */
@media (max-width: 576px) {
  h1 { font-size: 1.75rem; }
  h2 { font-size: 1.5rem; }
  h3 { font-size: 1.25rem; }
  h4 { font-size: 1.125rem; }
  
  .section-heading {
    font-size: 1.5rem;
    margin-bottom: var(--space-3);
  }
  
  .section-heading::after {
    width: 36px;
    height: 2px;
  }
  
  .section-subheading {
    font-size: 1rem;
    margin-bottom: var(--space-6);
  }
  
  .section-subsubheading {
    font-size: 0.875rem;
  }
  
  /* Timeline improvements for small mobile */
  .timeline::before {
    left: 30px;
  }
  
  .timeline > li {
    margin-bottom: var(--space-8);
  }
  
  .timeline > li .timeline-panel {
    padding: var(--space-3);
    margin-left: 50px;
    width: calc(100% - 50px);
  }
  
  .timeline > li .timeline-image {
    width: 50px;
    height: 50px;
    left: 0;
  }
  
  .timeline > li .timeline-image i {
    font-size: 1rem;
  }
  
  .timeline > li .timeline-image h4 {
    font-size: 0.5rem;
  }
  
  .timeline .timeline-heading h4 {
    font-size: 1rem;
  }
  
  .timeline .timeline-heading h4.subheading {
    font-size: 0.875rem;
  }
  
  .timeline .timeline-body > p {
    font-size: 0.875rem;
  }
  
  /* Teaching card mobile adjustments */
  .teaching-card {
    padding: var(--space-4);
  }
  
  .teaching-icon {
    width: 50px;
    height: 50px;
  }
  
  .teaching-icon i {
    font-size: 1.25rem;
  }
  
  /* Research card mobile adjustments */
  .research-card {
    padding: var(--space-4);
  }
  
  .research-card h4 {
    font-size: 1.125rem;
  }
  
  /* Conference item mobile adjustments */
  .conference-item {
    padding: var(--space-4);
  }
  
  .conference-item h4 {
    font-size: 1rem;
  }
  
  /* Expertise card mobile adjustments */
  .expertise-card {
    padding: var(--space-4);
  }
  
  .expertise-header {
    gap: var(--space-3);
    margin-bottom: var(--space-4);
  }
  
  .expertise-header i {
    font-size: 1.25rem;
    padding: var(--space-3);
  }
  
  .expertise-item {
    padding: var(--space-3);
  }
  
  /* Blog card mobile adjustments */
  .blog-card {
    padding: var(--space-4);
  }
  
  .blog-title {
    font-size: 1rem;
  }
  
  /* Achievement card mobile adjustments */
  .achievement-card {
    padding: var(--space-4);
  }
  
  /* Certification card mobile adjustments */
  .certification-card {
    padding: var(--space-4);
  }
  
  /* Portfolio caption mobile adjustments */
  .portfolio-caption {
    padding: var(--space-4);
  }
  
  .portfolio-caption h4 {
    font-size: 1rem;
  }
  
  .portfolio-caption p {
    font-size: 0.8125rem;
  }
  
  .portfolio-cta {
    margin-top: var(--space-3);
    padding-top: var(--space-3);
  }
  
  .portfolio-cta .btn {
    font-size: 0.75rem;
    padding: var(--space-1) var(--space-3);
  }
}

/* ===============================================
   RESEARCH SECTION
   =============================================== */

#research {
  background: var(--bg-primary) !important;
}

.research-card {
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-squircle);
  padding: var(--space-6);
  margin-bottom: var(--space-6);
  transition: all var(--transition-base);
}

.research-card:hover {
  border-color: var(--border-hover);
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

.research-card.featured {
  border-left: 4px solid var(--accent);
  background: linear-gradient(135deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
}

.research-card h4 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--space-2);
}

.research-meta {
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-bottom: var(--space-3);
  font-style: italic;
}

.publication-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  background: rgba(139, 90, 43, 0.1);
  padding: var(--space-2) var(--space-4);
  border-radius: calc(var(--radius-squircle) - 0.5rem);
  margin-bottom: var(--space-4);
  font-size: 0.875rem;
}

.publication-link i {
  color: var(--accent);
}

.publication-link a {
  color: var(--accent);
  font-weight: 500;
}

.publication-link a:hover {
  color: var(--accent-hover);
  text-decoration: underline;
}

.research-card ul {
  margin: var(--space-4) 0;
  padding-left: var(--space-6);
}

.research-card ul li {
  margin-bottom: var(--space-2);
  color: var(--text-secondary);
  font-size: 0.9375rem;
  line-height: 1.6;
}

.research-card ul li strong {
  color: var(--text-primary);
  font-weight: 600;
}

.research-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-top: var(--space-4);
}

.research-tags span {
  background: var(--bg-tertiary);
  color: var(--text-secondary);
  padding: var(--space-1) var(--space-3);
  border-radius: calc(var(--radius-squircle) - 0.75rem);
  font-size: 0.75rem;
  font-weight: 500;
  border: 1px solid var(--border);
}

/* ===============================================
   CONFERENCES SECTION
   =============================================== */

#conferences {
  background: var(--bg-secondary) !important;
}

.conference-item {
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-squircle);
  padding: var(--space-6);
  margin-bottom: var(--space-4);
  transition: all var(--transition-base);
}

.conference-item:hover {
  border-color: var(--border-hover);
  box-shadow: var(--shadow-md);
}

.presentation-type {
  display: inline-block;
  padding: var(--space-1) var(--space-3);
  border-radius: calc(var(--radius-squircle) - 0.75rem);
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: var(--space-3);
}

.presentation-type.oral {
  background: var(--accent);
  color: white;
}

.presentation-type.poster {
  background: var(--highlight);
  color: var(--text-primary);
}

.conference-item h4 {
  font-size: 1.0625rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--space-2);
  line-height: 1.4;
}

.conference-item p {
  font-size: 0.875rem;
  color: var(--text-muted);
  margin: 0;
}

/* ===============================================
   TEACHING SECTION
   =============================================== */

#teaching {
  background: var(--bg-primary) !important;
}

.teaching-card {
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-squircle);
  padding: var(--space-6);
  margin-bottom: var(--space-4);
  transition: all var(--transition-base);
  display: flex;
  gap: var(--space-6);
  align-items: flex-start;
}

.teaching-card:hover {
  border-color: var(--border-hover);
  box-shadow: var(--shadow-md);
}

.teaching-icon {
  flex-shrink: 0;
  width: 60px;
  height: 60px;
  background: var(--bg-secondary);
  border-radius: var(--radius-squircle);
  display: flex;
  align-items: center;
  justify-content: center;
}

.teaching-icon i {
  font-size: 1.5rem;
  color: var(--accent);
}

.teaching-card h4 {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--space-1);
}

.teaching-org {
  font-size: 0.9375rem;
  color: var(--accent);
  margin-bottom: var(--space-1);
  font-weight: 500;
}

.teaching-years {
  font-size: 0.8125rem;
  color: var(--text-muted);
  margin-bottom: var(--space-3);
}

.teaching-card > div:last-child p:last-child {
  color: var(--text-secondary);
  font-size: 0.9375rem;
  margin: 0;
}

@media (max-width: 768px) {
  .teaching-card {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }
}

/* ===============================================
   INSTITUTION BADGE (Hero)
   =============================================== */

.intro-institution {
  font-size: 1rem;
  color: rgba(255, 255, 255, 0.8);
  margin-top: var(--space-4);
  margin-bottom: var(--space-6);
  font-weight: 400;
}

/* Additional mobile text optimizations */
@media (max-width: 576px) {
  .intro-institution {
    margin-top: var(--space-3);
    margin-bottom: var(--space-4);
  }
  
  /* Ensure text doesn't overflow on small screens */
  header.masthead .intro-text {
    word-wrap: break-word;
    overflow-wrap: break-word;
  }
  
  /* Research tags on mobile */
  .research-tags {
    gap: var(--space-1);
  }
  
  .research-tags span {
    font-size: 0.6875rem;
    padding: var(--space-1) var(--space-2);
  }
}

/* ===============================================
   MOBILE CTA FIXES (Contact section + button spacing)
   =============================================== */

@media (max-width: 576px) {
  /* Global: prevent .btn-gradient from keeping large desktop margins */
  .btn-gradient {
    margin: var(--space-2) 0;
  }

  /* Hero: keep gradient button flush inside the hero action row */
  header.masthead .hero-actions .btn-gradient {
    margin: 0;
  }

  /* Contact section: force the two CTAs to stack and look centered */
  section#contact .btn-xl {
    display: block;
    width: 100%;
    max-width: 420px;
    margin-left: auto;
    margin-right: auto;
  }
}

/* ===============================================
   PRINT STYLES
   =============================================== */

@media print {
  body {
    background: white;
    color: black;
  }
  
  .navbar,
  .theme-toggle,
  footer {
    display: none;
  }
  
  section {
    page-break-inside: avoid;
  }
}