body {
  font-family: 'Segoe UI', Tahoma, sans-serif;
  margin: 0;
  padding: 0;
  background: #f4f6f8;
  color: #333;
  transition: background-color 0.5s ease, color 0.5s ease;
}

nav {
  background: #222;
  color: #fff;
  padding: 1rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-links {
  display: flex;
  gap: 2rem;
}

nav a {
  color: #fff;
  text-decoration: none;
  font-weight: 500;
  transition: color 0.3s;
}

nav a:hover {
  color: #00bcd4;
}

.dark-toggle {
  background: none;
  border: none;
  color: #fff;
  font-size: 1.2rem;
  cursor: pointer;
  transition: color 0.3s, opacity 0.3s;
}

.dark-toggle:hover {
  color: #00bcd4;
}

section {
  max-width: 900px;
  margin: 2rem auto;
  padding: 2rem;
  background: #fff;
  border-radius: 8px;
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
  transition: background-color 0.5s ease, color 0.5s ease;
}

h1, h2, h3 {
  margin-top: 0;
  color: #222;
  transition: color 0.5s ease;
}

ul {
  list-style: none;
  padding: 0;
}

ul li {
  margin: 0.5rem 0;
  padding: 0.5rem;
  background: #f9f9f9;
  border-radius: 4px;
}

.certificates {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1rem;
}

.certificate {
  text-align: center;
}

.img-container {
  position: relative;
  display: inline-block;
}

.img-container img {
  width: 100%;
  max-width: 300px;
  border-radius: 8px;
  cursor: pointer;
  transition: transform 0.3s, box-shadow 0.3s;
}

.img-container img:hover {
  transform: scale(1.05);
  box-shadow: 0 6px 16px rgba(0,0,0,0.2);
}

.hover-text {
  position: absolute;
  bottom: 10px;
  left: 50%;
  transform: translateX(-50%);
  background: rgba(0,0,0,0.7);
  color: #fff;
  padding: 6px 10px;
  border-radius: 4px;
  opacity: 0;
  transition: opacity 0.3s;
  white-space: nowrap;
  font-size: 0.9rem;
}

.img-container:hover .hover-text {
  opacity: 1;
}

.monkeytype-link {
  color: #ff9800;
  text-decoration: none;
  font-weight: 500;
  transition: color 0.3s;
}

.monkeytype-link:hover {
  color: #e65100;
  text-decoration: underline;
}

.social-links {
  display: flex;
  justify-content: center;
  gap: 1.5rem;
  margin-top: 1rem;
}

.social-links a {
  text-decoration: none;
  color: #333;
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  transition: color 0.3s, transform 0.3s;
}

.social-links a i {
  font-size: 1.5rem;
}

.social-links a.email:hover { color: #d93025; transform: scale(1.1); }
.social-links a.github:hover { color: #000; transform: scale(1.1); }
.social-links a.linkedin:hover { color: #0077b5; transform: scale(1.1); }
.social-links a.hackerrank:hover { color: #2ec866; transform: scale(1.1); }
.social-links a.codeforces:hover { color: #ff5722; transform: scale(1.1); }

body.dark-mode {
  background: #121212;
  color: #e0e0e0;
}

body.dark-mode nav {
  background: #1e1e1e;
}

body.dark-mode section {
  background: #1e1e1e;
  color: #e0e0e0;
  box-shadow: 0 4px 12px rgba(255,255,255,0.1);
}

body.dark-mode h1,
body.dark-mode h2,
body.dark-mode h3 {
  color: #fff;
}

body.dark-mode a {
  color: #80cbc4;
}

body.dark-mode .hover-text {
  background: rgba(255,255,255,0.2);
}

.lightbox {
  display: none;
  position: fixed;
  z-index: 999;
  left: 0; top: 0;
  width: 100%; height: 100%;
  background: rgba(0,0,0,0.8);
  justify-content: center;
  align-items: center;
}

.lightbox img {
  max-width: 90%;
  max-height: 90%;
  border-radius: 8px;
  box-shadow: 0 4px 20px rgba(0,0,0,0.5);
}

.tagline-boxes {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin: 1rem 0;
}

.tagline {
  background: #00bcd4;
  color: #fff;
  padding: 0.6rem 1.2rem;
  border-radius: 6px;
  font-weight: 600;
  box-shadow: 0 4px 10px rgba(0,0,0,0.15);
  transition: transform 0.3s, background-color 0.3s;
}

.tagline:hover {
  transform: translateY(-3px);
  background-color: #0097a7;
}

body.dark-mode .tagline {
  background: #80cbc4;
  color: #000;
}

body.dark-mode .tagline:hover {
  background: #4db6ac;
}

.certificate-viewer {
  margin-top: 2rem;
  display: flex;
  justify-content: center;
}

.certificate-viewer iframe {
  width: 90%;
  height: 600px;
  border: 2px solid #ccc;
  border-radius: 8px;
}

#skills p strong {
  color: #00bcd4;
}

#skills p:last-child {
  margin-top: 0.5rem;
}

#skills p:last-child span {
  background: #0097a7;
  color: #fff;
  padding: 2px 6px;
  border-radius: 4px;
  font-weight: 600;
}

.skill-boxes {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin: 1rem 0;
}

.skill {
  background: #00bcd4;
  color: #fff;
  padding: 0.6rem 1.2rem;
  border-radius: 6px;
  font-weight: 600;
  box-shadow: 0 4px 10px rgba(0,0,0,0.15);
  transition: transform 0.3s, background-color 0.3s;
}

.skill:hover {
  transform: translateY(-3px);
  background-color: #0097a7;
}

.skill.highlight {
  background: #ff9800;
  color: #fff;
}

body.dark-mode .skill {
  background: #80cbc4;
  color: #000;
}

body.dark-mode .skill:hover {
  background: #4db6ac;
}

body.dark-mode .skill.highlight {
  background: #ffb74d;
  color: #000;
}