/**
 * Modern Custom Styles for Portfolio
 * Design System: Modern, Premium, Accessible
 */

/* ============================================
   CSS Variables - Design System
   ============================================ */
:root {
  /* Colors */
  --color-primary: #0A8FA8;
  --color-primary-dark: #0085A1;
  --color-secondary: #6c757d;
  --color-accent: #2563eb;
  --color-bg: #ffffff;
  --color-bg-light: #f8f9fa;
  --color-text: #212529;
  --color-text-muted: #495057;
  --color-border: #dee2e6;
  
  /* Typography */
  --font-heading: 'Poppins', 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-size-base: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
  --font-size-h1: clamp(2rem, 1.5rem + 2.5vw, 3rem);
  --font-size-h2: clamp(1.75rem, 1.5rem + 1.25vw, 2.5rem);
  --font-size-h3: clamp(1.5rem, 1.25rem + 1.25vw, 2rem);
  --font-size-h4: clamp(1.25rem, 1.125rem + 0.625vw, 1.75rem);
  
  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-xxl: 4rem;
  
  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 300ms ease;
  --transition-slow: 500ms ease;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
  
  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  
  /* Breakpoints (for reference) */
  --breakpoint-sm: 576px;
  --breakpoint-md: 768px;
  --breakpoint-lg: 992px;
  --breakpoint-xl: 1200px;
  --breakpoint-xxl: 1400px;
}

/* ============================================
   Reset & Base Styles
   ============================================ */
* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

body {
  font-family: var(--font-body);
  font-size: var(--font-size-base);
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ============================================
   Typography
   ============================================ */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 600;
  line-height: 1.2;
  margin-top: 0;
  margin-bottom: var(--spacing-md);
  color: var(--color-text);
}

h1 {
  font-size: var(--font-size-h1);
}

h2 {
  font-size: var(--font-size-h2);
}

h3 {
  font-size: var(--font-size-h3);
}

h4 {
  font-size: var(--font-size-h4);
}

p {
  margin-bottom: var(--spacing-sm);
}

.lead {
  font-size: clamp(1.125rem, 1rem + 0.625vw, 1.25rem);
  font-weight: 400;
  line-height: 1.6;
}

/* ============================================
   Accessibility
   ============================================ */
.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--color-primary);
  color: white;
  padding: 8px;
  text-decoration: none;
  z-index: 100;
}

.skip-link:focus {
  top: 0;
}

:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* ============================================
   Navigation
   ============================================ */
.navbar {
  background-color: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-base);
  padding-top: var(--spacing-sm);
  padding-bottom: var(--spacing-sm);
}

.navbar.is-fixed {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  box-shadow: var(--shadow-md);
}

.navbar-brand {
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: clamp(1.125rem, 1rem + 0.625vw, 1.25rem);
  color: var(--color-text);
  text-decoration: none;
  transition: color var(--transition-fast);
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
}

.navbar-brand:hover {
  color: var(--color-primary);
}

.navbar-logo {
  max-height: 50px;
  height: auto;
  width: auto;
  transition: transform var(--transition-base);
  display: block;
  object-fit: contain;
}

.navbar-logo:hover {
  transform: scale(1.05);
}

/* Ensure navbar brand only shows logo, no text */
.navbar-brand span {
  display: none !important;
}

.nav-link {
  color: var(--color-text);
  font-weight: 500;
  transition: color var(--transition-fast);
  position: relative;
}

.nav-link:hover,
.nav-link:focus {
  color: var(--color-primary);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  width: 0;
  height: 2px;
  background-color: var(--color-primary);
  transition: all var(--transition-base);
  transform: translateX(-50%);
}

.nav-link:hover::after,
.nav-link.active::after {
  width: 80%;
}

/* Language Switcher */
.language-switcher {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  margin-left: var(--spacing-md);
}

.lang-btn {
  background: none;
  border: none;
  color: var(--color-text-muted);
  font-weight: 500;
  cursor: pointer;
  padding: 0.25rem 0.5rem;
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}

.lang-btn:hover,
.lang-btn.active {
  color: var(--color-primary);
  background-color: var(--color-bg-light);
}

.lang-separator {
  color: var(--color-border);
}

/* ============================================
   Hero / Masthead
   ============================================ */
.masthead {
  position: relative;
  margin-bottom: var(--spacing-xxl);
  padding-top: calc(8rem + 57px);
  padding-bottom: 8rem;
  background: no-repeat center center;
  background-size: cover;
  background-attachment: scroll;
}

.masthead::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(33, 37, 41, 0.65);
  backdrop-filter: blur(2px);
}

.masthead .site-heading {
  position: relative;
  z-index: 1;
  color: #ffffff !important;
  text-align: center;
}

.masthead .page-heading {
  position: relative;
  z-index: 1;
  color: #ffffff !important;
  text-align: center;
}

.masthead .page-heading h1,
.masthead .page-heading .h1 {
  color: #ffffff !important;
  text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.5), 0 0 10px rgba(0, 0, 0, 0.3);
  font-weight: 700;
}

.masthead .page-heading .subheading {
  color: #ffffff !important;
  text-shadow: 1px 1px 3px rgba(0, 0, 0, 0.5), 0 0 8px rgba(0, 0, 0, 0.3);
}

.masthead .site-heading h1 {
  color: #ffffff !important;
  margin-bottom: var(--spacing-md);
  white-space: normal;
  overflow: visible;
  text-overflow: clip;
  word-wrap: break-word;
  text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.5), 0 0 10px rgba(0, 0, 0, 0.3);
  font-weight: 700;
}

.profile-image {
  width: 280px;
  height: auto;
  display: block;
  margin: var(--spacing-lg) auto;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  border: 4px solid rgba(255, 255, 255, 0.2);
  transition: transform var(--transition-base);
}

.profile-image:hover {
  transform: scale(1.05);
}

.hero-social-links {
  display: flex;
  justify-content: center;
  gap: var(--spacing-md);
  margin: var(--spacing-md) 0;
  min-height: 48px;
}

.hero-social-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  background-color: rgba(255, 255, 255, 0.2);
  border-radius: 50%;
  color: #ffffff !important;
  font-size: 1.5rem;
  text-decoration: none;
  transition: all var(--transition-base);
  backdrop-filter: blur(10px);
  border: 2px solid rgba(255, 255, 255, 0.4);
  position: relative;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

.hero-social-link i,
.hero-social-link img {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  line-height: 1;
  display: inline-block !important;
  z-index: 10;
  opacity: 1 !important;
  visibility: visible !important;
  width: 24px;
  height: 24px;
  object-fit: contain;
}

.hero-social-link i {
  color: #ffffff !important;
  font-size: 1.5rem !important;
  width: auto;
  height: auto;
  text-align: center;
  font-style: normal;
  font-variant: normal;
  text-rendering: auto;
  -webkit-font-smoothing: antialiased;
}

.hero-social-link .sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}

.hero-social-link:hover {
  background-color: rgba(255, 255, 255, 0.3);
  transform: translateY(-3px) scale(1.1);
  border-color: rgba(255, 255, 255, 0.6);
  color: #ffffff !important;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

.hero-social-link:hover i,
.hero-social-link:hover img {
  transform: translate(-50%, -50%);
  opacity: 1 !important;
}

.hero-social-link:hover i {
  color: #ffffff !important;
}

.subheading {
  font-size: clamp(1rem, 0.875rem + 0.625vw, 1.25rem);
  font-weight: 300;
  line-height: 1.4;
  display: block;
  margin-top: var(--spacing-sm);
  text-align: center;
  white-space: normal;
  overflow: visible;
  text-overflow: clip;
  word-wrap: break-word;
  color: #ffffff !important;
  text-shadow: 1px 1px 3px rgba(0, 0, 0, 0.5), 0 0 8px rgba(0, 0, 0, 0.3);
}

/* Subtitle styles - allow wrapping and center alignment */
header.masthead .site-heading .subheading,
.masthead .site-heading .subheading,
header.masthead .site-heading .subheading strong,
.masthead .site-heading .subheading strong {
  white-space: normal;
  display: block;
  overflow: visible;
  text-overflow: clip;
  word-break: normal;
  word-wrap: break-word;
  text-align: center;
  color: #ffffff !important;
  text-shadow: 1px 1px 3px rgba(0, 0, 0, 0.5), 0 0 8px rgba(0, 0, 0, 0.3);
}

/* Hero title - allow wrapping for long names */
header.masthead .site-heading h1,
.masthead .site-heading h1,
header.masthead .site-heading .h1 {
  white-space: normal;
  overflow: visible;
  text-overflow: clip;
  word-break: normal;
  word-wrap: break-word;
}

@media (min-width: 992px) {
  .masthead {
    padding-top: 12.5rem;
    padding-bottom: 12.5rem;
  }
  
  .masthead .site-heading h1 {
    font-size: clamp(3rem, 2rem + 5vw, 5rem);
    white-space: normal;
  }
}

/* ============================================
   Sections
   ============================================ */
.home-section {
  padding: var(--spacing-xxl) 0;
  position: relative;
}

.home-section-bg {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: var(--color-bg-light);
  opacity: 0.5;
  z-index: -1;
}

.featurette-heading {
  font-size: var(--font-size-h2);
  font-weight: 600;
  margin-bottom: var(--spacing-lg);
  color: var(--color-text);
}

hr {
  margin: var(--spacing-xl) 0;
  border: 0;
  border-top: 1px solid var(--color-border);
  opacity: 0.25;
}

/* ============================================
   Experience Section
   ============================================ */
.experience-item {
  background: var(--color-bg);
  border-radius: var(--radius-md);
  padding: var(--spacing-lg);
  margin-bottom: var(--spacing-lg);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-base);
}

.experience-item:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.experience-header {
  margin-bottom: var(--spacing-md);
}

.experience-header h3 {
  margin-bottom: var(--spacing-xs);
  color: var(--color-primary);
}

.experience-meta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
  font-size: 0.9rem;
  color: var(--color-text-muted);
}

.experience-meta .company {
  font-weight: 600;
  color: var(--color-text);
}

.experience-impact,
.experience-stack {
  margin-top: var(--spacing-lg);
}

.experience-impact h4,
.experience-stack h4 {
  font-size: var(--font-size-h4);
  margin-bottom: var(--spacing-sm);
  color: var(--color-text);
}

.experience-impact ul {
  list-style: none;
  padding-left: 0;
}

.experience-impact ul li {
  position: relative;
  padding-left: var(--spacing-md);
  margin-bottom: var(--spacing-sm);
}

.experience-impact ul li::before {
  content: '▸';
  position: absolute;
  left: 0;
  color: var(--color-primary);
  font-weight: bold;
}

.tech-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-xs);
  margin-top: var(--spacing-sm);
}

.tech-tag {
  display: inline-block;
  padding: 0.375rem 0.75rem;
  background-color: var(--color-bg-light);
  color: var(--color-text);
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 500;
  border: 1px solid var(--color-border);
  transition: all var(--transition-fast);
}

.tech-tag:hover {
  background-color: var(--color-primary);
  color: white;
  border-color: var(--color-primary);
  transform: translateY(-2px);
}

/* ============================================
   Publications & Projects
   ============================================ */
.pub-list-item {
  margin-bottom: var(--spacing-lg);
  padding: var(--spacing-md);
  background: var(--color-bg);
  border-radius: var(--radius-md);
  border-left: 3px solid var(--color-primary);
  transition: all var(--transition-base);
}

.pub-list-item:hover {
  box-shadow: var(--shadow-md);
  transform: translateX(4px);
}

.pub-icon {
  color: var(--color-primary);
  margin-right: var(--spacing-xs);
}

.article-metadata {
  display: block;
  margin-bottom: var(--spacing-xs);
  font-size: 0.9rem;
  color: var(--color-text-muted);
}

.article-metadata a {
  color: var(--color-text);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.article-metadata a:hover {
  color: var(--color-primary);
}

.btn-links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-xs);
  margin-top: var(--spacing-sm);
}

.btn {
  display: inline-block;
  padding: 0.5rem 1rem;
  font-weight: 500;
  text-align: center;
  text-decoration: none;
  border-radius: var(--radius-sm);
  transition: all var(--transition-base);
  border: 1px solid transparent;
  cursor: pointer;
}

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

.btn-outline-primary:hover {
  background-color: var(--color-primary);
  color: white;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn-sm {
  padding: 0.375rem 0.75rem;
  font-size: 0.875rem;
}

.see-all {
  margin-top: var(--spacing-xl);
  text-align: center;
}

.see-all a {
  color: var(--color-primary);
  font-weight: 600;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  transition: all var(--transition-base);
}

.see-all a:hover {
  gap: var(--spacing-sm);
  transform: translateX(4px);
}

/* ============================================
   Footer
   ============================================ */
footer {
  background-color: var(--color-bg-light);
  padding: var(--spacing-xl) 0;
  margin-top: var(--spacing-xxl);
}

.footer-copyright {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  flex-wrap: wrap;
  margin-top: var(--spacing-md);
}

.footer-logo-link {
  display: inline-flex;
  align-items: center;
  text-decoration: none;
}

.footer-logo-img {
  max-height: 30px;
  height: auto;
  width: auto;
  transition: transform var(--transition-base);
  opacity: 0.8;
  vertical-align: middle;
}

.footer-logo-img:hover {
  transform: scale(1.1);
  opacity: 1;
}

.list-inline {
  list-style: none;
  padding-left: 0;
  margin-bottom: var(--spacing-md);
}

.list-inline-item {
  display: inline-block;
  margin: 0 var(--spacing-xs);
}

.fa-stack {
  transition: transform var(--transition-base);
}

.fa-stack:hover {
  transform: scale(1.1);
}

.fa-stack a {
  color: var(--color-text-muted);
  transition: color var(--transition-fast);
}

.fa-stack a:hover {
  color: var(--color-primary);
}

/* ============================================
   Responsive Design
   ============================================ */
@media (max-width: 768px) {
  .home-section {
    padding: var(--spacing-xl) 0;
  }
  
  .experience-meta {
    flex-direction: column;
    gap: 0.25rem;
  }
  
  .language-switcher {
    margin-left: 0;
    margin-top: var(--spacing-sm);
  }
  
  .profile-image {
    width: 200px;
  }
  
  .navbar-logo {
    max-height: 35px;
  }
  
  .footer-logo-img {
    max-height: 30px;
  }
  
  /* Hero title and subtitle on mobile - allow wrapping */
  header.masthead .site-heading h1,
  .masthead .site-heading h1 {
    white-space: normal;
    font-size: clamp(1.5rem, 4vw, 2.5rem);
  }
  
  header.masthead .site-heading .subheading,
  .masthead .site-heading .subheading,
  .masthead .site-heading .subheading strong {
    white-space: normal;
    font-size: clamp(0.875rem, 2vw, 1rem);
    text-align: center;
  }
}

/* ============================================
   Animations (Reveal on Scroll)
   ============================================ */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* ============================================
   Utility Classes
   ============================================ */
.text-center {
  text-align: center;
}

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

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

.mt-4 {
  margin-top: var(--spacing-lg);
}

/* Container adjustments */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

@media (min-width: 768px) {
  .container {
    padding: 0 var(--spacing-lg);
  }
}