:root {
  --primary-color: #00e5ff; 
  --secondary-color: #00b8d4; 
  --accent-color: #64ffda; 
  --glow-color-primary: rgba(0, 229, 255, 0.5);
  --glow-color-accent: rgba(100, 255, 218, 0.5);

  --text-color: #f0f4f8; 
  --text-color-medium: #a8b2d1; 
  --text-color-light: #8892b0; 

  --bg-color-darkest: #0a192f; 
  --bg-color-dark: #112240; 
  --bg-color-medium: #1f2937; 
  --bg-color-light: #374151; 

  --border-color: #3a506b; 
  --shadow-color: rgba(2, 12, 27, 0.7);
  --shadow-color-light: rgba(0, 0, 0, 0.3); 

  --gradient-primary: linear-gradient(
    90deg,
    var(--primary-color) 0%,
    var(--accent-color) 100%
  );
  --gradient-border: linear-gradient(
    90deg,
    transparent,
    var(--primary-color),
    transparent
  );
  --gradient-radial-glow: radial-gradient(
      circle at 10% 20%,
      transparent 0%,
      transparent 80%,
      rgba(0, 229, 255, 0.1) 100%
    ),
    radial-gradient(
      circle at 90% 80%,
      transparent 0%,
      transparent 80%,
      rgba(100, 255, 218, 0.1) 100%
    );

  /* Fonts */
  --font-family-main: "Poppins", sans-serif;
  --font-family-code: "SF Mono", "Fira Code", "Fira Mono", "Roboto Mono",
    monospace;

  --font-size-xs: 0.75rem; 
  --font-size-sm: 0.875rem; 
  --font-size-md: 1rem; 
  --font-size-lg: 1.125rem; 
  --font-size-xl: 1.25rem; 
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 1.875rem; 
  --font-size-4xl: 2.5rem; 
  --font-size-5xl: 3rem; 
  --font-size-6xl: 4rem; 

  --line-height-tight: 1.2;
  --line-height-normal: 1.6;
  --line-height-loose: 1.8;


  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem; 
  --spacing-md: 1rem; 
  --spacing-lg: 1.5rem; 
  --spacing-xl: 2rem; 
  --spacing-2xl: 3rem; 
  --spacing-3xl: 4rem; 
  --spacing-4xl: 6rem; 
  --spacing-section: 8rem; 

  --border-width: 1px;
  --border-width-thick: 2px;
  --border-radius-sm: 4px;
  --border-radius-md: 8px;
  --border-radius-lg: 16px;
  --border-radius-xl: 24px;
  --border-radius-full: 9999px;

  --transition-fast: 0.15s ease-out;
  --transition-normal: 0.3s ease-in-out;
  --transition-slow: 0.5s ease-in-out;
  --transition-bounce: 0.5s cubic-bezier(0.68, -0.55, 0.27, 1.55);


  --z-background: -1;
  --z-base: 1;
  --z-content: 10;
  --z-navigation: 100;
  --z-overlay: 200;
  --z-modal: 1000;
  --z-cursor: 9999;

  --container-width: 1200px;
  --header-height: 70px;
  --blur-amount: 8px;
}

/*2.Base & Reset*/
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

/* Default Dark Theme (applied via :root) */
body {
  font-family: var(--font-family-main);
  background-color: var(--bg-color-darkest);
  color: var(--text-color); /* Default text for dark mode */
  line-height: var(--line-height-normal);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
  position: relative;
  transition: background-color var(--transition-normal), color var(--transition-normal); /* Smooth transition */
}

.particles-container {
  position: fixed;
  inset: 0;
  z-index: calc(var(--z-background) + 1);
  pointer-events: none;
}

#neural-network-canvas, 
#hero-neural-network {
  position: absolute;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100dvh;
  max-height: 100dvh;
  opacity: 0.6;
  z-index: -1;
  pointer-events: none;
  
}

/*3.Layout --- */
.container {
  width: 100%;
  max-width: var(--container-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--spacing-lg);
  padding-right: var(--spacing-lg);
}

.section {
  padding: var(--spacing-section) 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column; 
  justify-content: center; 
  align-items: center; 
  position: relative;
  overflow: hidden; 
}

.section::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--border-width);
  background: var(--gradient-border);
  opacity: 0.5; 
}

/*4.Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
  color: var(--text-color);
  line-height: var(--line-height-tight);
  margin-bottom: var(--spacing-md);
}

h1 { font-size: var(--font-size-5xl); }
h2 { font-size: var(--font-size-4xl); } 
h3 { font-size: var(--font-size-2xl); } 
h4 { font-size: var(--font-size-xl); }
h5 { font-size: var(--font-size-lg); }
h6 { font-size: var(--font-size-md); }

p {
  margin-bottom: var(--spacing-md);
  max-width:auto; 
}

a {
  color: var(--primary-color);
  text-decoration: none;
  transition: color var(--transition-fast), filter var(--transition-fast);
}

a:hover, a:focus {
  color: var(--secondary-color);
  filter: brightness(1.1);
  outline: none; 
}

img, svg {
  max-width: 100%;
  height: auto;
  display: flex; 
}

ul, ol {
  list-style-position: inside;
  margin-bottom: var(--spacing-md);
  padding-left: var(--spacing-md); 
}

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

code, pre {
  font-family: var(--font-family-code);
  font-size: var(--font-size-sm);
  background-color: rgba(0, 229, 255, 0.05);
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--border-radius-sm);
  color: var(--text-color-light);
}

pre {
  padding: var(--spacing-md);
  overflow-x: auto;
  white-space: pre-wrap; 
  word-wrap: break-word;
}

/*5.Header & Navigation*/
header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: var(--z-navigation);
  background-color: rgba(10, 25, 47, 0.85);
  backdrop-filter: blur(var(--blur-amount));
  transition: background-color var(--transition-normal), box-shadow var(--transition-normal), height var(--transition-normal);
  height: var(--header-height);
  display: flex;
  align-items: center;
  box-shadow: 0 2px 10px var(--shadow-color);
}

header.scrolled {
  background-color: rgba(10, 25, 47, 0.95);
  box-shadow: 0 4px 15px var(--shadow-color);
}

#navbar {
  display: flex;
  justify-content: center;
  align-items: center;
  width: 100%; 
}


.nav-links {
  display: flex;
  align-items: center;
  gap: var(--spacing-lg);
}

.nav-link {
  color: var(--text-color);
  font-weight: 500;
  font-size: var(--font-size-sm); 
  position: relative;
  padding: var(--spacing-sm) 0; 
  transition: color var(--transition-fast);
}

.nav-link::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0; 
  width: 0%;
  height: 2px;
  background: var(--gradient-primary);
  box-shadow: 0 0 8px var(--glow-color-primary);
  transition: width var(--transition-normal);
}

.nav-link:hover::after,
.nav-link.active::after { 
  width: 100%;
}

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

/* Mobile Menu Button */
.mobile-menu-btn {
  display: none; 
  flex-direction: column;
  justify-content: space-between;
  width: 28px;
  height: 20px;
  cursor: pointer;
  z-index: calc(var(--z-navigation) + 1);
  background: none;
  border: none;
}

.mobile-menu-btn span {
  display: block; 
  width: 100%;
  height: 2px;
  background-color: var(--text-color);
  border-radius: var(--border-radius-sm);
  transition: transform var(--transition-normal), opacity var(--transition-normal);
}

.mobile-menu-btn.active span:nth-child(1) {
  transform: translateY(9px) rotate(45deg);
}
.mobile-menu-btn.active span:nth-child(2) {
  opacity: 0;
}
.mobile-menu-btn.active span:nth-child(3) {
  transform: translateY(-9px) rotate(-45deg);
}

/*6.Hero Section*/
#hero {
  min-height: 100vh; 
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  position: relative;
}

.hero-content {
  max-width: flex; 
  z-index: var(--z-content);
}

.hero-content h1 {
  font-size: clamp(var(--font-size-3xl), 8vw, var(--font-size-6xl)); 
  font-weight: 700; 
  margin-bottom: var(--spacing-sm);
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  background-clip: text;
  text-shadow: 0 0 15px var(--glow-color-primary), 0 0 25px var(--glow-color-accent);
  letter-spacing: -1px;
}

.hero-content h2 {
  font-size: clamp(var(--font-size-lg), 4vw, var(--font-size-2xl));
  font-weight: 400; 
  color: #d6e0ff;
  margin-bottom: var(--spacing-lg);
  letter-spacing: 0.5px;
}

.tagline { 
  font-size: var(--font-size-lg);
  margin-bottom: var(--spacing-xl);
}

.hero-cta {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--spacing-md);
  margin-top: var(--spacing-xl);
}

/*7.Buttons*/
.btn {
  display: inline-flex; 
  align-items: center;
  justify-content: center;
  padding: var(--spacing-sm) var(--spacing-lg);
  border-radius: var(--border-radius-full);
  font-weight: 600;
  font-size: var(--font-size-sm);
  border: none;
  cursor: pointer;
  transition: all var(--transition-normal);
  text-align: center;
  white-space: nowrap; 
}

.primary-btn {
  background: var(--gradient-primary);
  color: var(--bg-color-darkest); 
  box-shadow: 0 4px 15px rgba(0, 229, 255, 0.3); 
}

.primary-btn:hover, .primary-btn:focus {
  transform: translateY(-3px) scale(1.03);
  box-shadow: 0 8px 25px var(--glow-color-primary);
  filter: brightness(1.1);
  color: var(--bg-color-darkest);
}

.secondary-btn {
  background-color: transparent;
  color: var(--primary-color);
  border: var(--border-width-thick) solid var(--primary-color);
  box-shadow: 0 0 10px rgba(0, 229, 255, 0.2); 
}

.secondary-btn:hover, .secondary-btn:focus {
  background-color: rgba(0, 229, 255, 0.1);
  transform: translateY(-3px);
  box-shadow: 0 0 20px var(--glow-color-primary);
  color: var(--primary-color);
}

/*8.Section Title*/
.section-title {
  font-size: var(--font-size-4xl);
  margin-bottom: var(--spacing-3xl); 
  position: relative;
  display: inline-block; 
  color: var(--text-color);
}

.section-title::after {
  content: "";
  position: absolute;
  bottom: calc(-1 * var(--spacing-md)); /* Position below text */
  left: 50%; /* Center align */
  transform: translateX(-50%);
  width: 70px; /* Initial width */
  height: 3px;
  background: var(--gradient-primary);
  border-radius: var(--border-radius-full);
  box-shadow: 0 0 10px var(--glow-color-primary);
  /* Keep pulsing animation if desired */
  animation: width-pulse 3s ease-in-out infinite;
}

@keyframes width-pulse {
  0%, 100% { width: 70px; }
  50% { width: 100px; }
}

.about-content {
  display: flex;
  flex-direction: column; 
  align-items: center;
  gap: var(--spacing-2xl);
  max-width: 1200px; 
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

.image-container {
  flex: 0 0 300px; 
  max-width: 100%;
  aspect-ratio: 1 / 1;
  border-radius: var(--border-radius-lg);
  overflow: hidden;
  position: relative;
  box-shadow: 0 10px 30px var(--shadow-color);
  transition: transform var(--transition-slow), box-shadow var(--transition-slow);
}

.profile-pic {
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: inherit; 
  transition: transform var(--transition-slow), filter var(--transition-slow);
  filter: grayscale(70%) contrast(1.1);
}

.image-container:hover {
  transform: scale(1.03);
  box-shadow: 0 15px 40px var(--shadow-color), 0 0 20px var(--glow-color-primary);
}

.image-container:hover .profile-pic {
  transform: scale(1.1); 
  filter: grayscale(0%) contrast(1); 
}


@media (min-width: 768px) {
  .about-content {
    flex-direction: row;
    justify-content: space-between;
    align-items: flex-start;
  }

}

.about-text {
  flex: 1; 
  max-width: 700px; 
  text-align: left; 
}

.about-text p {
  color: var(--text-color-medium);
  max-width: 600px;
}

.skills {
  margin-top: var(--spacing-xl);
}

.skill-category {
  margin-bottom: var(--spacing-lg);
}

.skill-category h3 {
  font-size: var(--font-size-lg);
  margin-bottom: var(--spacing-md);
  color: var(--primary-color); 
  font-weight: 600;
}

.skills-list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
}

.skill-tag {
  background-color: rgba(0, 229, 255, 0.1);
  color: var(--text-color);
  padding: var(--spacing-xs) var(--spacing-md);
  border-radius: var(--border-radius-sm); 
  font-size: var(--font-size-sm);
  border: var(--border-width) solid rgba(0, 229, 255, 0.3);
  transition: all var(--transition-fast);
  cursor: default; 
}

.skill-tag:hover {
  background-color: rgba(0, 229, 255, 0.2);
  color: var(--primary-color);
  transform: translateY(-2px);
  box-shadow: 0 0 10px rgba(0, 229, 255, 0.3);
}

/*10.Projects Section --- */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: var(--spacing-xl);
  width: 100%; 
}

.project-card {
  background-color: rgba(31, 41, 55, 0.6); 
  backdrop-filter: blur(var(--blur-amount));
  border: var(--border-width) solid var(--border-color);
  border-radius: var(--border-radius-md); 
  overflow: hidden;
  box-shadow: 0 5px 15px var(--shadow-color-light);
  transition: transform var(--transition-normal), box-shadow var(--transition-normal), border-color var(--transition-normal);
  display: flex; 
  flex-direction: column;
  position: relative; 
  z-index: var(--z-base);
}

.project-card::after { 
  content: "";
  position: absolute;
  inset: 0;
  background: var(--gradient-radial-glow);
  pointer-events: none;
  z-index: -1; 
  opacity: 0;
  transition: opacity var(--transition-normal);
}

.project-card:hover {
  transform: translateY(-8px);
  box-shadow: 0 15px 35px var(--shadow-color), 0 0 15px var(--glow-color-primary);
  border-color: var(--primary-color);
}

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

.project-image {
  height: 200px;
  overflow: hidden;
  background-color: var(--bg-color-light);
}

.project-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition-slow), filter var(--transition-slow);
  filter: contrast(0.9) brightness(0.9);
}

.project-card:hover .project-image img {
  transform: scale(1.05);
  filter: contrast(1) brightness(1); 
}

.project-content {
  padding: var(--spacing-lg);
  flex-grow: 1; 
  display: flex;
  flex-direction: column;
}

.project-content h3 {
  font-size: var(--font-size-xl);
  margin-bottom: var(--spacing-sm);
  color: var(--text-color);
}

.project-content p {
  color: var(--text-color-light);
  margin-bottom: var(--spacing-md);
  font-size: var(--font-size-sm);
  flex-grow: 1; 
}

.project-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-xs);
  margin-bottom: var(--spacing-md);
}

.project-tags span {
  background-color: var(--bg-color-dark);
  color: var(--text-color-light);
  padding: calc(var(--spacing-xs) / 2) var(--spacing-sm);
  border-radius: var(--border-radius-sm);
  font-size: var(--font-size-xs); 
  font-family: var(--font-family-code); 
  border: 1px solid var(--border-color);
}

.project-links {
  display: flex;
  gap: var(--spacing-lg);
  margin-top: auto;
}

.project-link {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--text-color-light); 
  transition: color var(--transition-fast);
}

.project-link:hover {
  color: var(--primary-color); 
}

.project-link .icon {
  width: 18px; 
  height: 18px;
  fill: currentColor;
}

/*11.Experience Section(Timeline)*/
.timeline {
  position: relative;
  width: 100%; 
  max-width: 800px;
  margin: 0 auto;
  padding: var(--spacing-xl) 0; 
}

.timeline::before { /*vertical Bar*/
  content: "";
  position: absolute;
  top: 0;
  left: 20px; 
  height: 100%;
  width: 2px;
  background: linear-gradient(
    to bottom,
    var(--primary-color) 0%,
    var(--accent-color) 70%,
    transparent 100%
  );
  z-index: var(--z-base);
}

.timeline-item {
  position: relative;
  padding-left: 60px;
  margin-bottom: var(--spacing-2xl);
}

.timeline-item {
  opacity: 0;
  transform: translateX(-20px);
  transition: opacity var(--transition-slow), transform var(--transition-slow);
}
.timeline-item.visible { 
  opacity: 1;
  transform: translateX(0);
}

.timeline-item:nth-child(odd).visible { transition-delay: 0.1s; }
.timeline-item:nth-child(even).visible { transition-delay: 0.2s; }


.timeline-dot {
  position: absolute;

  left: 11px; 
  top: 8px; 
  width: 18px; 
  height: 18px;
  border-radius: 50%;
  background: var(--gradient-primary);
  z-index: calc(var(--z-base) + 1);
  box-shadow: 0 0 15px var(--glow-color-primary);

  animation: pulse 2s infinite ease-in-out;
}

@keyframes pulse {
  0% { transform: scale(1); box-shadow: 0 0 15px var(--glow-color-primary); }
  50% { transform: scale(1.1); box-shadow: 0 0 25px var(--glow-color-primary); }
  100% { transform: scale(1); box-shadow: 0 0 15px var(--glow-color-primary); }
}

.timeline-date {
  font-size: var(--font-size-sm);
  font-weight: 500; /* Normal weight */
  color: var(--text-color-light); /* Less prominent */
  margin-bottom: var(--spacing-xs);
  font-family: var(--font-family-code); /* Code font for dates */
}

.timeline-content {
  background-color: var(--bg-color-medium); /* Use variable */
  padding: var(--spacing-lg);
  border-radius: var(--border-radius-md);
  box-shadow: 0 5px 15px var(--shadow-color-light);
  border: 1px solid var(--border-color);
  transition: border-color var(--transition-normal), box-shadow var(--transition-normal);
}
.timeline-item:hover .timeline-content {
  border-color: var(--primary-color);
  box-shadow: 0 8px 20px var(--shadow-color), 0 0 10px var(--glow-color-primary);
}

.timeline-content h3 { /* Job Title / Position */
  font-size: var(--font-size-lg);
  margin-bottom: var(--spacing-xs);
  color: var(--text-color);
}

.timeline-content h4 { /* Company Name */
  font-size: var(--font-size-md);
  color: var(--primary-color); /* Highlight company */
  font-weight: 500;
  margin-bottom: var(--spacing-md);
}

.timeline-content ul {
  list-style-type: none; /* Remove default bullets */
  padding-left: 0;
  color: var(--text-color-medium);
}

.timeline-content li {
  margin-bottom: var(--spacing-sm);
  position: relative;
  padding-left: var(--spacing-lg); /* Space for custom bullet */
  font-size: var(--font-size-sm);
}

.timeline-content li::before { /* Custom bullet */
  content: "▹"; /* Use a suitable character */
  position: absolute;
  left: 0;
  top: 0;
  color: var(--primary-color);
  font-weight: bold;
}


/* --- 12. Organizations Section --- */
#organizations {
  background-color: rgba(17, 34, 64, 0.3); /* Subtle background difference */
}

.organizations-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); /* Smaller cards */
  gap: var(--spacing-lg);
  margin-top: var(--spacing-xl);
  width: 100%;
}

.organization-card {
  background-color: rgba(31, 41, 55, 0.7);
  backdrop-filter: blur(calc(var(--blur-amount) / 2)); /* Less blur */
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-md);
  overflow: hidden;
  padding: var(--spacing-lg);
  box-shadow: 0 5px 15px var(--shadow-color-light);
  transition: transform var(--transition-normal), box-shadow var(--transition-normal), border-color var(--transition-normal);
  text-align: center;
}

.organization-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 25px var(--shadow-color), 0 0 10px var(--glow-color-primary);
  border-color: var(--primary-color);
}

.organization-logo {
  width: 60px; /* Smaller logo */
  height: 60px;
  margin: 0 auto var(--spacing-md);
  background-color: rgba(0, 229, 255, 0.1);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid rgba(0, 229, 255, 0.3);
  transition: transform var(--transition-normal);
}
.organization-card:hover .organization-logo {
    transform: scale(1.1);
}

.organization-logo svg {
  width: 30px; /* Smaller SVG */
  height: 30px;
  fill: var(--primary-color);
}

.organization-name {
  font-size: var(--font-size-md); /* Smaller name */
  font-weight: 600;
  margin-bottom: var(--spacing-xs);
  color: var(--text-color); /* White name */
}

.organization-role {
  font-size: var(--font-size-sm);
  color: var(--primary-color); /* Highlight role */
  margin-bottom: var(--spacing-sm);
  font-weight: 500;
}

.organization-period {
  font-size: var(--font-size-xs);
  color: var(--text-color-light);
  opacity: 0.8;
  font-family: var(--font-family-code);
}

/* --- 13. Certificates Section --- */
#certificates .container {
  max-width: 80%; /* Limit width for slider */
}

.certificates-wrapper { /* New wrapper for layout */
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-lg);
}

.certificate-viewer {
  width: 100%; /* Full width within wrapper */
  max-width: 700px; /* Max width for the image/info */
  position: relative;
  overflow: hidden;
  border-radius: var(--border-radius-lg);
  background-color: rgba(31, 41, 55, 0.7);
  backdrop-filter: blur(var(--blur-amount));
  border: 1px solid var(--border-color);
  box-shadow: 0 10px 30px var(--shadow-color);
  min-height: 400px; /* Ensure minimum height */
  display: flex; /* Use flex for slide positioning */
}

.certificate-slider {
  display: flex;
  width: 100%; /* Should contain all slides horizontally */
  transition: transform var(--transition-slow); /* Animate slide transition */
}

.certificate-slide {
  min-width: 100%; /* Each slide takes full viewer width */
  padding: var(--spacing-xl);
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  opacity: 0; /* Hidden by default */
  visibility: hidden;
  position: absolute; /* Overlay slides */
  transition: opacity var(--transition-slow), visibility var(--transition-slow);
  left: 0;
  top: 0;
}

.certificate-slide.active {
  opacity: 1;
  visibility: visible;
  position: relative; /* Take up space when active */
}

.certificate-slide img {
  max-width: 100%;
  max-height: 300px; /* Limit image height */
  height: auto;
  border-radius: var(--border-radius-md);
  cursor: pointer; /* Indicate clickable */
  transition: transform var(--transition-normal), box-shadow var(--transition-normal);
  box-shadow: 0 5px 15px var(--shadow-color-light);
  border: 1px solid var(--border-color);
}

.certificate-slide img:hover {
  transform: scale(1.03);
  box-shadow: 0 8px 25px var(--glow-color-primary);
}

.certificate-slide h3 {
  margin-top: var(--spacing-lg);
  font-size: var(--font-size-lg); /* Slightly smaller title */
  color: var(--primary-color);
}

.certificate-slide p { /* Issuer/Date */
  margin-top: var(--spacing-xs);
  color: var(--text-color-light);
  font-size: var(--font-size-sm);
}

.certificate-navigation {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-lg); /* More space */
  margin-top: var(--spacing-md); /* Space above controls */
}

.certificate-nav-btn {
  background-color: rgba(0, 229, 255, 0.1);
  border: 1px solid var(--primary-color);
  color: var(--primary-color);
  width: 45px; /* Slightly smaller */
  height: 45px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-normal);
}

.certificate-nav-btn:hover:not(:disabled) {
  background-color: var(--primary-color);
  color: var(--bg-color-darkest);
  transform: scale(1.1);
  box-shadow: 0 0 15px var(--glow-color-primary);
}
.certificate-nav-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    border-color: var(--border-color);
    color: var(--text-color-light);
}


.certificate-nav-btn .icon {
  width: 20px; /* Smaller icon */
  height: 20px;
  fill: currentColor;
}

.certificate-counter {
  font-size: var(--font-size-sm);
  color: var(--text-color-light);
  font-family: var(--font-family-code);
}

.current-certificate {
  color: var(--primary-color);
  font-weight: bold;
}

/* Certificate Modal */
.certificate-modal {
  position: fixed;
  inset: 0;
  background-color: rgba(10, 25, 47, 0.9); /* Darker overlay */
  backdrop-filter: blur(5px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: var(--z-modal);
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-normal), visibility var(--transition-normal);
}

.certificate-modal.active {
  opacity: 1;
  visibility: visible;
}

.certificate-modal-content {
  max-width: 90vw; /* Limit width by viewport */
  max-height: 90vh; /* Limit height by viewport */
  position: relative;
}

.certificate-modal-content img {
  display: block; /* Remove extra space */
  max-width: 100%;
  max-height: 90vh; /* Ensure image fits vertically */
  border-radius: var(--border-radius-sm); /* Small radius */
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.5);
}

.certificate-modal-close {
  position: absolute;
  top: -15px;
  right: -15px;
  width: 36px;
  height: 36px;
  background-color: var(--primary-color);
  border: none;
  border-radius: 50%;
  color: var(--bg-color-darkest);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-normal);
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.3);
}

.certificate-modal-close:hover {
  transform: scale(1.1) rotate(90deg);
  background-color: var(--secondary-color);
}

.certificate-modal-close .icon {
  width: 20px;
  height: 20px;
  fill: currentColor;
}


/* --- 14. Contact Section --- */
.contact-content {
  display: grid;
  grid-template-columns: 1fr; /* Stack columns by default */
  gap: var(--spacing-2xl);
  width: 100%;
  max-width: 1000px; /* Max width for the contact section */
}

.contact-info {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
}

.contact-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  font-size: var(--font-size-sm);
}

.contact-item .icon {
  width: 20px; /* Smaller icons */
  height: 20px;
  fill: var(--primary-color);
  flex-shrink: 0; /* Prevent icon shrinking */
}
.contact-item a {
    word-break: break-all; /* Prevent long links overflowing */
}


.contact-form {
  background-color: rgba(31, 41, 55, 0.7);
  backdrop-filter: blur(calc(var(--blur-amount) / 2));
  border: 1px solid var(--border-color);
  padding: var(--spacing-xl);
  border-radius: var(--border-radius-lg);
  box-shadow: 0 10px 30px var(--shadow-color);
  position: relative;
  overflow: hidden; /* For shine effect */
}


.btn-spinner {
  display: inline-block;
  width: 16px;
  height: 16px;
  border: 2px solid transparent;
  border-top: 2px solid white;
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  margin-left: 8px;
  vertical-align: middle;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

/* Optional: Shine effect - can be distracting */
/* .contact-form::before { ... } */
/* @keyframes shine { ... } */

.form-group {
  margin-bottom: var(--spacing-lg);
}

.form-group label {
  display: block;
  margin-bottom: var(--spacing-sm); /* More space */
  font-weight: 500;
  font-size: var(--font-size-sm);
  color: var(--text-color-light);
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: var(--spacing-md);
  border: var(--border-width) solid var(--border-color);
  border-radius: var(--border-radius-md);
  background-color: var(--bg-color-dark); /* Darker input bg */
  color: var(--text-color);
  font-family: inherit;
  font-size: var(--font-size-md);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-group textarea {
  resize: vertical;
  min-height: 150px; /* Taller text area */
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(0, 229, 255, 0.2), 0 0 10px var(--glow-color-primary); /* Focus ring + glow */
}

.contact-form button[type="submit"] {
  width: 100%; /* Full width submit */
  margin-top: var(--spacing-sm); /* Space above button */
}

/* --- 15. Footer --- */
footer {
  background-color: var(--bg-color-dark); /* Darker footer */
  padding: var(--spacing-lg) 0;
  text-align: center;
  border-top: 1px solid var(--border-color);
  margin-top: var(--spacing-section); /* Space above footer */
}

footer .container {
  display: flex;
  flex-direction: column; /* Stack elements on small screens */
  justify-content: space-between;
  align-items: center;
  gap: var(--spacing-md);
}

.footer-text { /* Wrap the copyright text */
  font-size: var(--font-size-sm);
  color: var(--text-color-light);
}

.social-links { /* Add a container for social icons */
    display: flex;
    gap: var(--spacing-lg);
}
.social-links a {
    color: var(--text-color-light);
    transition: color var(--transition-fast), transform var(--transition-fast);
}
.social-links a:hover {
    color: var(--primary-color);
    transform: translateY(-3px);
}
.social-links .icon {
    width: 24px;
    height: 24px;
    fill: currentColor;
}


.back-to-top { /* Style the link directly if preferred */
  display: inline-flex; /* Use inline-flex */
  justify-content: center;
  align-items: center;
  width: 40px;
  height: 40px;
  background-color: rgba(0, 229, 255, 0.1); /* Subtle background */
  border: 1px solid var(--primary-color);
  color: var(--primary-color);
  border-radius: 50%;
  transition: all var(--transition-normal);
}

.back-to-top:hover {
  background-color: var(--primary-color);
  color: var(--bg-color-darkest);
  transform: translateY(-5px) scale(1.1);
  box-shadow: 0 0 15px var(--glow-color-primary);
}

.back-to-top .icon {
  width: 20px;
  height: 20px;
  fill: currentColor;
}

/* --- 16. Animations & Effects --- */

/* Fade-in (Generic - Use with JS observer) */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}
.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Fade-Slide (Alternative) */
.fade-slide {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.8s cubic-bezier(0.645, 0.045, 0.355, 1), transform 0.8s cubic-bezier(0.645, 0.045, 0.355, 1);
}
.fade-slide.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Delay helper classes */
.delay-1 { transition-delay: 0.1s; }
.delay-2 { transition-delay: 0.2s; }
.delay-3 { transition-delay: 0.3s; }
.delay-4 { transition-delay: 0.4s; }


/* Custom Cursor (Optional - Can impact performance/UX) */
.cursor, .cursor-follower {
    display: none; /* Hide by default, enable if desired */
}


/* Futuristic Scrollbar */
::-webkit-scrollbar {
  width: 8px;
}
::-webkit-scrollbar-track {
  background: var(--bg-color-dark);
}
::-webkit-scrollbar-thumb {
  background: linear-gradient(to bottom, var(--primary-color), var(--accent-color));
  border-radius: var(--border-radius-full);
  border: 2px solid var(--bg-color-dark); /* Create track separation */
}
::-webkit-scrollbar-thumb:hover {
  background: var(--primary-color);
  box-shadow: 0 0 10px var(--glow-color-primary);
}
/* Firefox scrollbar - less customizable */
/* html { scrollbar-color: var(--primary-color) var(--bg-color-dark); scrollbar-width: thin; } */


/* Glitch Animation (Use sparingly) */
@keyframes glitch {
  /* Keep original keyframes or simplify if needed */
  0%, 14%, 100% {
    text-shadow: 0.05em 0 0 var(--glow-color-primary), -0.05em -0.025em 0 var(--glow-color-accent);
  }
  15%, 49% {
    text-shadow: -0.05em -0.025em 0 var(--glow-color-primary), 0.025em 0.025em 0 var(--glow-color-accent);
  }
  50%, 99% {
    text-shadow: 0.025em 0.05em 0 var(--glow-color-primary), 0.05em 0 0 var(--glow-color-accent);
  }
}

/* --- 17. Responsive Design --- */

/* Large Screens (adjust breakpoint if needed) */
@media (min-width: 769px) {
  .about-content {
    flex-direction: row; /* Side-by-side on larger screens */
    text-align: left;
    gap: var(--spacing-3xl); /* More gap */
  }
  .about-text {
    flex: 1; /* Take more space */
    text-align: left;
  }
  .image-container {
    flex-basis: 1 1 350px; /* Fixed width */
    flex-shrink: 0; /* Prevent shrinking */
    width: auto; 
    max-width: 100%;/* Override smaller screen width */
  }
  .contact-content {
      grid-template-columns: 1fr 1.5fr; /* Info | Form */
      align-items: start; /* Align items to top */
  }
  .contact-form button[type="submit"] {
      width: auto; /* Auto width on larger screens */
      min-width: 150px;
  }
  footer .container {
      flex-direction: row; /* Side-by-side footer content */
  }
}

/* Tablets and Smaller Desktops */
@media (max-width: 992px) {
  :root {
    /* Slightly reduce large font sizes */
    --font-size-6xl: 3.5rem;
    --font-size-5xl: 2.75rem;
    --font-size-4xl: 2.25rem;
  }
  .projects-grid {
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  }
}

/* Mobile Devices */
@media (max-width: 768px) {
  :root {
    /* Further reduce font sizes */
    --font-size-6xl: 3rem;
    --font-size-5xl: 2.5rem;
    --font-size-4xl: 2rem;
    --font-size-3xl: 1.75rem;
    --spacing-section: 6rem; /* Less vertical space */
    --header-height: 60px; /* Shorter header */
  }

  .section-title {
      font-size: var(--font-size-3xl); /* Smaller section titles */
      margin-bottom: var(--spacing-2xl);
  }
  .section-title::after {
      bottom: calc(-1 * var(--spacing-sm));
  }

  /* Mobile Navigation */
  .nav-links {
    position: fixed;
    top: 0;
    right: -100%; /* Off-screen */
    width: min(75vw, 300px); /* Responsive width */
    height: 100vh;
    background-color: var(--bg-color-dark); /* Slightly different bg */
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: var(--spacing-xl); /* More gap between mobile links */
    transition: right var(--transition-normal);
    box-shadow: -5px 0 20px var(--shadow-color);
    z-index: calc(var(--z-navigation) - 1); /* Below header */
    padding-top: var(--header-height); /* Avoid overlapping header */
  }
  .nav-links.active {
    right: 0; /* Slide in */
  }
  .nav-link {
      font-size: var(--font-size-md); /* Larger links in mobile menu */
  }

  .mobile-menu-btn {
    display: flex; /* Show hamburger */
  }

  .theme-toggle {
      margin-left: auto; /* Push toggle to the right side of logo */
      margin-right: var(--spacing-lg);
  }
  #navbar .nav-links .theme-toggle {
      display: none; /* Hide theme toggle inside nav links container on mobile */
  }

  .hero-content h1 {
      letter-spacing: -0.5px;
  }

  .timeline::before {
      left: 15px; /* Adjust line position */
  }
  .timeline-item {
      padding-left: 45px; /* Adjust item padding */
  }
  .timeline-dot {
      left: 6px; /* Adjust dot position */
      width: 16px;
      height: 16px;
  }

  .certificates-wrapper {
      width: 95%; /* Slightly wider on mobile */
  }
   .certificate-viewer {
       min-height: 350px;
   }
   .certificate-slide img {
       max-height: 250px;
   }
   .certificate-navigation {
       gap: var(--spacing-md);
   }
   .certificate-nav-btn {
       width: 40px;
       height: 40px;
   }
}

/* Very Small Devices */
@media (max-width: 480px) {
  :root {
    --font-size-5xl: 2rem;
    --font-size-4xl: 1.75rem;
    --font-size-3xl: 1.5rem;
    --spacing-lg: 1rem; /* Reduce padding/gaps */
    --spacing-xl: 1.5rem;
  }
  .container {
    padding-left: var(--spacing-md);
    padding-right: var(--spacing-md);
  }
  .hero-cta {
    flex-direction: column; /* Stack buttons */
    align-items: center; /* Center stacked buttons */
    gap: var(--spacing-md);
  }
  .primary-btn, .secondary-btn {
      width: 80%; /* Make buttons wider */
  }
  .projects-grid {
    grid-template-columns: 1fr; /* Single column */
  }
  .organizations-grid {
    grid-template-columns: 1fr; /* Single column */
  }
  .contact-content {
      gap: var(--spacing-xl);
  }
  .contact-form {
      padding: var(--spacing-lg);
  }
}